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74,200,516 | https://en.wikipedia.org/wiki/NGC%202110 | NGC 2110 is a lenticular galaxy located in the constellation Orion. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 2110 is about 90,000 light years across. It was discovered by William Herschel on October 5, 1785. It is a Seyfert galaxy.
Characteristics
NGC 2110 has been categorised as a lenticular galaxy, but it had been categorised as an elliptical galaxy in the past. Images by Hubble Space Telescope revealed the presence of curved dust lanes about one arcsecond west of the nucleus. A bar of material measuring 90 by 35 parsec has been found in the nucleus in infrared.
In the circumnuclear region have been found 4 star clusters by Keck Observatory in the near infrared, that form a semicircular structure with a diameter of 90 parsecs, while observations by Gemini Observatory indicate the presence of ring with stars of intermediate age (100–700 million years) with diameter of 140 parsecs. Closer to the nucleus, the star population is predominately old.
Active nucleus
The nucleus of NGC 2110 has been found to be active, as it a bright source of X-rays, and it has been categorised as a type II Seyfert galaxy. Type 2 Seyfert galaxies are characterised by the presence of narrow emission lines, but a broad double-peaked H-alpha emission line has been detected indicating the presence of a broad line region that is hidden by a dust torus.
The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole. The mass of the black hole in the centre of NGC 2110 is estimated to be (1.95 billion) based on velocity dispersion or when using the M–sigma relation.
NGC 2110 has been found to emit X-rays. The X-ray spectrum is similar to that of Seyfert 1 galaxies that is obstructed by a complex absorber, with column densities between 4 and 30 × 1022/cm2 as measured by BeppoSAX. The presence of a patchy absorber around the nucleus along with a uniform one of lower column density was confirmed with observations made by Chandra X-ray Observatory, XMM Newton, and Suzaku. Although the FeKα line is detected, there is no detectable reflection element. The line appears to come from two components, one from distant Compton-thick material and one variable from material close to the black hole. The temperature of the hot corona of the nucleus is estimated to be keV.
When observed in radio waves, the galaxy features radio emission that extends for 4 arcseconds. The centre of the emission coincides with the nucleus, and from it emanate two jets, one north and one south, with S-shaped morphology. Similarly, north of the nucleus has been found in OIII and H-alpha+NII imaging a narrow strongly curved outflow that is one arcsecond long and looks like a jet. H-alpha imaging also reveals the presence of ionised gas in an s-shaped pattern that extends for 4 arcseconds north and south of the nucleus. In the region 4 arcseconds north of the nucleus, just beyond the end of the radio jet, has been found soft X-rays emission by Chandra X-ray Observatory. There is also soft X-rays emission south of the nucleus that extends for 30 arcseconds.
Gas kinematics of the central region of NGC 2110 indicate that there is an inflow of cold gas of 2.2 × 10−2 per year while the outflow of gas is estimated to be 0.9 or 0.5 per year. The outflow causes gas to be blueshifted by 100 km/s to the southwest of the nucleus and to be redshifted by 40 km/s to the northeast. Other kinematic components in the central region of the galaxy are a cold gas disk, with velocity dispersion of 60–90 km/s, a hot gas disk, with velocity dispersion of 220–600 km/s, and a cloud of ionised gas 1–4 arcseconds north of the nucleus. The region of the north ionised cloud is devoid of CO 2–1 emission.
See also
NGC 1386 - a similar Seyfert 2 galaxy
References
External links
NGC 2110 on SIMBAD
Lenticular galaxies
Seyfert galaxies
Orion (constellation)
2110
18030
Discoveries by William Herschel
Astronomical objects discovered in 1785 | NGC 2110 | [
"Astronomy"
] | 961 | [
"Constellations",
"Orion (constellation)"
] |
74,200,735 | https://en.wikipedia.org/wiki/Paul%20Brombacher | Paul Jacob Brombacher (10 October 1930 – 2 July 2020) was a Dutch clinical chemist, professor at Maastricht University and the head clinical chemist at in Heerlen.
Personal life
Paul Brombacher was born on 10 October 1930 in Rotterdam, Netherlands and he died on 2 July 2020 in Heerlen, Netherlands. His wife, Prijna Everdina Brombacher-Binnendijk was born in Noordwijk, Netherlands on 23 October 1931 and she died on 6 April 2021 in Heerlen, Netherlands. His sister, Jannie Brombacher was a major in the Royal Netherlands Army.
Paul spoke fluent Dutch, German, English, Italian, French and intermediate Spanish, Hebrew and Arabic.
Academic career
In 1955, Brombacher completed a Master's degree in Chemistry with a minor in Physiology at the Free University of Amsterdam. Afterwards he worked as a clinical chemist in the Antoni van Leeuwenhoekziekenhuis (hospital) of the Netherlands Cancer Institute. In 1960, he became the head of the clinical chemistry laboratory of the hospital and the clinical chemistry research laboratory of the Free University of Amsterdam. In April 1964, he became the new head clinical chemist at (later renamed to ) in Heerlen, Netherlands.
On 9 May 1975, he received a Doctor of Medicine from the Free University of Amsterdam. His research on adrenal cortex hormones took place entirely in De Wever Hospital. Despite not being funded, he continued his research during his private time due to the lack of a research budget.
In December 1994 he retired from De Wever Hospital after working there for thirty years, and later in 1995 he retired from professorship at the Rijksuniversiteit Limburg (now Maastricht University).
Publications
Brombacher was the Dutch national editor of the European Journal of Clinical Chemistry and Clinical Biochemistry in 1991. He was the lead author for works in the following peer-reviewed journals:
Clinica Chimica Acta
Annals of Clinical Biochemistry
Clinical Chemistry
The Lancet
Drug Research
Awards
1991 he received the Gorter en De Graaff-prijs ( and De Graaf Prize) for his clinical chemistry work.
In 1994 he became an officer in the Order of Orange-Nassau.
References
External links
1930 births
2020 deaths
Dutch biochemists
Clinical chemists
Academic staff of Maastricht University
Vrije Universiteit Amsterdam alumni
People from Heerlen
Dutch academics
Officers of the Order of Orange-Nassau
Scientists from Rotterdam
20th-century Dutch chemists | Paul Brombacher | [
"Chemistry"
] | 512 | [
"Biochemists",
"Clinical chemists"
] |
74,201,328 | https://en.wikipedia.org/wiki/Six-dimensional%20holomorphic%20Chern%E2%80%93Simons%20theory | In mathematical physics, six-dimensional holomorphic Chern–Simons theory or sometimes holomorphic Chern–Simons theory is a gauge theory on a three-dimensional complex manifold. It is a complex analogue of Chern–Simons theory, named after Shiing-Shen Chern and James Simons who first studied Chern–Simons forms which appear in the action of Chern–Simons theory. The theory is referred to as six-dimensional as the underlying manifold of the theory is three-dimensional as a complex manifold, hence six-dimensional as a real manifold.
The theory has been used to study integrable systems through four-dimensional Chern–Simons theory, which can be viewed as a symmetry reduction of the six-dimensional theory. For this purpose, the underlying three-dimensional complex manifold is taken to be the three-dimensional complex projective space , viewed as twistor space.
Formulation
The background manifold on which the theory is defined is a complex manifold which has three complex dimensions and therefore six real dimensions. The theory is a gauge theory with gauge group a complex, simple Lie group The field content is a partial connection .
The action is
where
where is a holomorphic (3,0)-form and with denoting a trace functional which as a bilinear form is proportional to the Killing form.
On twistor space P3
Here is fixed to be . For application to integrable theory, the three form must be chosen to be meromorphic.
See also
Chern–Simons theory
Four-dimensional Chern-Simons theory
External links
Holomorphic Chern–Simons theory nLab
References
Gauge theories
Integrable systems | Six-dimensional holomorphic Chern–Simons theory | [
"Physics"
] | 346 | [
"Integrable systems",
"Theoretical physics"
] |
74,202,786 | https://en.wikipedia.org/wiki/Dislon | A dislon is a quantized field associated with the quantization of the lattice displacement in crystalline solids. It is a localized collective excitation of a crystal dislocation.
Description
Dislons are special quasiparticles that emerge from the quantization of the lattice displacement field around a dislocation in a crystal. They exhibit unique particle statistics depending on the dimension of quantization. In one-dimensional quantization, dislons behave as bosonic quasiparticles. However, in three-dimensional quantization, the topological constraint of the dislocation leads to a breakdown of the canonical commutation relation, resulting in the emergence of two independent bosonic fields known as the d-field and f-field.
Interaction
Dislons interact with other particles such as electrons and phonons. In the presence of multiple dislocations, the electron-dislon interaction can affect the electrical conductivity of the system. The distance-dependent interaction between electrons and dislocations leads to oscillations in the electron self-energy away from the dislocation core.
Applications
The study of dislons provides insights into various phenomena in materials science, including the variation of superconducting transition temperatures in dislocated crystals. Dislons play a role in understanding the interaction between dislocations and phonons, affecting thermal transport properties in the presence of dislocations.
See also
Quasiparticle
Special theory of relativity
List of particles
List of quasiparticles
Strong interaction
References
Physical phenomena
Condensed matter physics
Quantum phases
Quasiparticles
Mesoscopic physics | Dislon | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 334 | [
"Quantum phases",
"Matter",
"Physical phenomena",
"Phases of matter",
"Quantum mechanics",
"Materials science",
"Condensed matter physics",
"Quasiparticles",
"Mesoscopic physics",
"Subatomic particles"
] |
74,202,973 | https://en.wikipedia.org/wiki/Phoniton | A phoniton is a theoretical quasiparticle that emerges from the hybridization of a localized, long-lived phonon (a quantum of sound) with a matter excitation. It serves as a sound-based analogue of cavity quantum electrodynamics, where the phonon plays a role similar to that of a photon in coupling with a matter excitation to form a polariton.
The concept of phonitons was introduced in research conducted by Soykal et al. In their study, they explore the possibility of realizing these hybrid objects based on sound and matter. By investigating strained silicon systems, the authors identify low-lying donor transitions that can be driven solely by acoustic phonons at wavelengths suitable for constructing high-Q phonon cavities. The strongly coupled regime of the phonon-matter resonance is achieved, surpassing the thresholds of spontaneous phonon emission, phonon leakage, anharmonicity, and scattering. The proposed micropillar distributed Bragg reflector Si/Ge cavity demonstrates the feasibility of achieving high-Q factors and small mode volumes.
Phonitons offer exciting prospects in manipulating quantized vibrations in nanoscale mechanical systems and gaining deeper insights into the nature of sound and heat at the quantum level. phonitons can serve as fundamental components in constructing new macroscopic artificial quantum systems.
See also
Quasiparticle
Cavity quantum electrodynamics
Quantum mechanics
References
Quantum mechanics
Quasiparticles | Phoniton | [
"Physics",
"Materials_science"
] | 304 | [
"Matter",
"Theoretical physics",
"Quantum mechanics",
"Condensed matter physics",
"Quasiparticles",
"Subatomic particles"
] |
74,203,091 | https://en.wikipedia.org/wiki/Configuron | A configuron is an elementary configurational excitation in an amorphous material which involves breaking of a chemical bond. Coined by scientists C.A. Angell and K.J. Rao, this concept often involves the breaking and reforming of a chemical bond.
These configurational excitations, or configurons, serve as a crucial aspect of understanding the dynamic behaviors of amorphous materials. Essentially, these are the fundamental building blocks that dictate the arrangements of atoms or molecules within these substances.
Understanding configurons can open avenues in various fields, such as materials science and electronics, by allowing more precise manipulation of amorphous materials' properties.
See also
Quasiparticle
Amorphous solid
Condensed matter physics
Configuration interaction
References
Condensed matter physics
Materials science
Quasiparticles
Amorphous solids | Configuron | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 170 | [
"Matter",
"Applied and interdisciplinary physics",
"Phases of matter",
"Materials science",
"Unsolved problems in physics",
"Condensed matter physics",
"nan",
"Quasiparticles",
"Amorphous solids",
"Subatomic particles"
] |
74,204,240 | https://en.wikipedia.org/wiki/Reactances%20of%20synchronous%20machines | The reactances of synchronous machines comprise a set of characteristic constants used in the theory of synchronous machines. Technically, these constants are specified in units of the electrical reactance (ohms), although they are typically expressed in the per-unit system and thus dimensionless. Since for practically all (except for the tiniest) machines the resistance of the coils is negligibly small in comparison to the reactance, the latter can be used instead of (complex) electrical impedance, simplifying the calculations.
Two reactions theory
The air gap of the machines with a salient pole rotor is quite different along the pole axis (so called direct axis) and in the orthogonal direction (so called quadrature axis). Andre Blondel in 1899 proposed in his paper "Empirical Theory of Synchronous Generators" the two reactions theory that divided the armature magnetomotive force (MMF) into two components: the direct axis component and the quadrature axis component. The direct axis component is aligned with the magnetic axis of the rotor, while the quadrature (or transverse) axis component is perpendicular to the direct axis. The relative strengths of these two components depend on the design of the machine and the operating conditions. Since the equations naturally split into direct and quadrature components, many reactances come in pairs, one for the direct axis (with the index d), one for the quadrature axis (with the index q). This is often using direct-quadrature-zero transformation.
In machines with a cylindrical rotor the air gap is uniform, the reactances along the d and q axes are equal, and d/q indices are frequently dropped.
States of the generator
The flux linkages of the generator vary with its state. Usually applied for transients after a short circuit current. Three states are considered:
the steady-state is the normal operating condition with the armature magnetic flux going through the rotor;
the sub-transient state () is the one the generator enters immediately after the fault (short circuit). In this state the armature flux is pushed completely out of the rotor. The state is very brief, as the current in the damper winding quickly decays allowing the armature flux to enter the rotor poles only. The generator goes into transient state;
in the transient state () the flux is still out of the field winding of the rotor. The transient state decays to steady-state in few cycles.
The sub-transient () and transient () states are cheracterized by significantly smaller reactances.
Leakage reactances
The nature of magnetic flux makes it inevitable that part of the flux deviates from the intended "useful" path. In most designs, the productive flux links the rotor and stator; the flux that links just the stator (or the rotor) to itself is useless for energy conversion and thus is considered to be wasted leakage flux (stray flux). The corresponding inductance is called leakage inductance. Due to the presence of air gap, the role of the leakage flux is more important in a synchronous machine in comparison to a transformer.
Synchronous reactances
The synchronous reactances are exhibited by the armature in the steady-state operation of the machine. The three-phase system is viewed as a superposition of two: the direct one, where the maximum of the phase current is reached when the pole is oriented towards the winding and the quadrature one, that is 90° offset.
The per-phase reactance can be determined in a mental experiment where the rotor poles are perfectly aligned with a specific angle of the phase field in the armature (0° for , 90° for the ). In this case, the reactance will be related with the flux linkage and the phase current as , where is the circular frequency. The conditions for this mental experiment are hard to recreate in practice, but:
when the armature is short-circuited, the flowing current is practically all reactive (as the coil resistance is negligible), thus under the short-circuit condition the poles of the rotor are aligned with the armature magnetomotive force;
when the armature is left open-circuit, the voltage on the terminals is also aligned with the same phase and is equal to . If saturation is neglected, the flux linkage is the same.
Therefore, the direct synchronous reactance can be determined as a ratio of the voltage in open condition to short-circuit current : . These current and voltage values can be obtained from the open-circuit saturation curve and the synchronous impedance curve.
The synchronous reactance is a sum of the leakage reactance and the reactance of the armature itself (): .
Sequence network reactances
When analyzing unbalanced three-phase systems it is common to describe a system of symmetrical components. This models the machine by three components, each with a positive sequence reactance , a negative sequence reactance and a
zero sequence reactance .
List of reactances
Das identifies the following reactances:
leakage reactance . Potier reactance is an estimate of the armature leakage reactance;
synchronous reactance (also );
transient reactance ;
subtransient reactance ;
quadrature axis reactances , , , counterparts to , , ;
negative sequence reactance ;
zero sequence reactance .
References
Sources
Electrical engineering
Electrical generators | Reactances of synchronous machines | [
"Physics",
"Technology",
"Engineering"
] | 1,137 | [
"Physical systems",
"Electrical generators",
"Machines",
"Electrical engineering"
] |
74,208,712 | https://en.wikipedia.org/wiki/Curium%28III%29%20iodide | Curium(III) iodide is the chemical compound with the formula . Since all isotopes of curium are only artificially produced, the compound has no natural occurrence.
Synthesis
Elemental curium and iodine can be reacted to synthesize curium(III) iodide.
Also by the reaction of curium(III) chloride with ammonium iodide:
Physical properties
Curium(III) iodide is a colorless ionic compound consisting of Cm3+ and I− ions. It forms white crystals the hexagonal crystal system in the space group R3 (space group no. 148) with the lattice parameters a = 744 pm and c = 2040 pm with six units per unit cell. Its crystal structure is isotypic with that of bismuth(III) iodide.
References
Curium compounds
Nuclear materials
Iodides
Actinide halides | Curium(III) iodide | [
"Physics"
] | 183 | [
"Materials",
"Nuclear materials",
"Matter"
] |
74,209,694 | https://en.wikipedia.org/wiki/Domain-specific%20architecture | A domain-specific architecture (DSA) is a programmable computer architecture specifically tailored to operate very efficiently within the confines of a given application domain. The term is often used in contrast to general-purpose architectures, such as CPUs, that are designed to operate on any computer program.
History
In conjunction with the semiconductor boom that started in the 1960s, computer architects were tasked with finding new ways to exploit the increasingly large number of transistors available. Moore's Law and Dennard Scaling enabled architects to focus on improving the performance of general-purpose microprocessors on general-purpose programs.
These efforts yielded several technological innovations, such as multi-level caches, out-of-order execution, deep instruction pipelines, multithreading, and multiprocessing. The impact of these innovations was measured on generalist benchmarks such as SPEC, and architects were not concerned with the internal structure or specific characteristics of these programs.
The end of Dennard Scaling pushed computer architects to switch from a single, very fast processor to several processor cores. Performance improvement could no longer be achieved by simply increasing the operating frequency of a single core.
The end of Moore's Law shifted the focus away from general-purpose architectures towards more specialized hardware. Although general-purpose CPU will likely have a place in any computer system, heterogeneous systems composed of general-purpose and domain-specific components are the most recent trend for achieving high performance.
While hardware accelerators and ASIC have been used in very specialized application domains since the inception of the semiconductor industry, they generally implement a specific function with very limited flexibility. In contrast, the shift towards domain-specific architectures wants to achieve a better balance of flexibility and specialization.
A notable early example of a domain-specific programmable architecture are GPUs. These specialized hardware were developed specifically to operate within the domain of image processing and computer graphics. These programmable processing units found widespread adoption both in gaming consoles and personal computers. With the improvement of the hardware/software stack for both NVIDIA and AMD GPUs, these architectures are being used more and more for the acceleration of massively and embarrassingly parallel tasks, even outside of the domain of image processing.
Since the renaissance of machine-learning-based artificial intelligence in the 2010s, several domain-specific architectures have been developed to accelerate inference for different forms of artificial neural networks. Some examples are Google's TPU, NVIDIA's NVDLA and ARM's MLP.
Guidelines for DSA design
John Hennessy and David Patterson outlined five principles for DSA design that lead to better area efficiency and energy savings. The objective in these types of architecture is often also to reduce the Non-Recurring Engineering (NRE) costs so that the investment in a specialized solution can be more easily amortized.
Minimize the distance over which data is moved: moving data in general-purpose memory hierarchies requires a remarkable amount of energy in order to attempt to minimize the latency to access data. In the case of Domain-Specific Architectures, it is expected that understanding the application domains by hardware and compiler designers allows for simpler and specialized memory hierarchies, where the data movement is largely handled in software, with tailor-made memories for specific functions within the domain.
Invest saved resources into arithmetic units or bigger memories: since a remarkable amount of hardware resources can be saved by dropping general-purpose architectural optimizations such as out-of-order execution, prefetching, address coalescing, and hardware speculation, the resources saved should be re-invested to maximally exploit the available parallelism, for example, by adding more arithmetic units or solve any memory bandwidth issues by adding bigger memories.
Use the easiest form of parallelism that matches the domain: since the target application domains almost always present an inherent form of parallelism, it is important to decide how to take advantage of this parallelism and expose it to the software. If, for example, a SIMD architecture can work in the domain, it would be easier for the programmer to use than a MIMD architecture.
Reduce data size and type to the simplest needed for the domain: whenever possible, using narrower and simpler data types yields several advantages. For example, it reduces the cost of moving data for memory-bound applications, and it can also reduce the amount of resources required to implement the respective arithmetic units.
Use a domain-specific programming language to port code to the DSA: one of the challenges for DSAs is ease of use, and more specifically, being able to effectively program the architecture and run applications on it. Whenever possible, it is advised to use existing Domain-Specific Languages (DSL) such as Halide and TensorFlow to more easily program a DSA. Re-use of existing compiler toolchains and software frameworks makes using a new DSA significantly more accessible.
DSA for deep neural networks
One of the application domains where DSA have found the most amount of success is that of artificial intelligence. In particular, several architectures have been developed for the acceleration of Deep Neural Networks (DNN). In the following sections, we report some examples.
TPU
Google's TPU was developed in 2015 to accelerate DNN inference since the company projected that the use of voice search would require to double the computational resources allocated at the time for neural network inference.
The TPU was designed to be a co-processor communicating via a PCIe bus, to be easily incorporated in existing servers. It is primarily a matrix-multiplication engine following a CISC (Complex Instruction Set Computer) ISA. The multiplication engine uses systolic execution to save energy, reducing the number of writes to SRAM.
The TPU was fabricated with a 28-nm process and clocked at 700MHz. The portion of the application that runs on the TPU is implemented in TensorFlow.
The TPU computes primarily reduced precision integers, which further contributes to energy savings and increased performance.
Microsoft Catapult
Microsoft's Project Catapult put an FPGA connected through a PCIe bus into data center servers, with the idea of using the FPGA to accelerate various applications running on the server, leveraging the reconfiguration capabilities of FPGA to accelerate many different applications.
Differently from Google's TPU, the Catapult FPGA needed to be programmed via hardware-description languages such as Verilog and VHDL. For this reason, a major concern for the authors of the framework was the limited programmability.
Microsoft designed a CNN accelerator for the Catapult framework that was primarily designed to accelerate the ranking function in the Bing search engine. The proposed architecture provided a runtime reconfigurable design based on a two-dimensional systolic array.
NVDLA
NVDLA is NVIDIA's deep-learning inference accelerator. It is an open-source hardware design available in a number of highly parametrizable configurations. The small-NVDLA model is designed to be deployed in resource-constrained scenarios such as IoT where cost, area and power are the main concerns. Conversely. the large-NVDLA model is more suitable for HPC scenarios. NVDLA provides its own dedicated training infrastructure, compilation tools and runtime software stack.
DSA for other domains
Aside from an application in artificial intelligence, DSAs are being adopted in many domains within scientific computing, image processing, and networking.
Pixel Visual Core
The Pixel Visual Core (PVC) is an of ARM-based image processors designed by Google. The PVC is a fully programmable image, vision and AI multi-core domain-specific architecture (DSA) for mobile devices and in future for IoT. It first appeared in the Google Pixel 2 and 2 XL which were introduced on October 19, 2017. It has also appeared in the Google Pixel 3 and 3 XL. Starting with the Pixel 4, this chip was replaced with the Pixel Neural Core.
Anton3
Anton3 is a DSA designed to efficiently compute molecular-dynamics simulations. It uses a specialized 3D torus topology interconnection network to connect several computing nodes. Each computing node contains a set of 64 cores interconnected through a mesh. The cores implement a specialized deep pipeline to efficiently compute the force-field between molecules. This heterogeneous system combines general-purpose hardware and domain-specific components to achieve record-breaking simulation speed.
References
Further reading
Computer Architecture. A Quantitative Approach. Sixth Edition. John L. Hennessy. Stanford University. David A. Patterson. University of California, Berkeley.
See also
Hardware Accelerator
AI Accelerator
ASIC
FPGA
Computer architecture | Domain-specific architecture | [
"Technology",
"Engineering"
] | 1,767 | [
"Computers",
"Computer engineering",
"Computer architecture"
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74,209,797 | https://en.wikipedia.org/wiki/LUMIO%20%28space%20mission%29 | LUnar Meteoroid Impact Observer (LUMIO) is a planned ESA lunar exploration mission expected to launch as early as 2027. The main goal of the mission is to detect, quantify, and characterize the impacts of near-Earth meteoroids on the lunar far side. The spacecraft consists of a 12-U CubeSat that will operate in a halo orbit around the L2 Lagrange point of the Earth-Moon system. It is an autonomus mission of the European Space Agency and is currently being developed by an international consortium which includes Politecnico di Milano, Argotec, Leonardo, IMT, Nautilus and S&T Norway.
The main scientific payload of LUMIO is a custom-designed optical camera, called LUMIO-Cam, which will observe the lunar surface in umbra to detect the flashes caused by asteroid impacts. Scientific data from the mission will be integrated with observations from the Earth to elaborate the first complete and accurate model of meteoroids flux in the lunar environment.
Background
Near-Earth meteoroids are fragments of asteroids and comets with sizes ranging from micrometers to meters. These objects impact the Earth and Moon on a daily basis. It is estimated that ~33 tons of these fragments get attracted into Earth's atmosphere every day. However, due to the extreme heat of the atmospheric entry, only a few manage to reach the surface. Since the Moon has no atmosphere, lunar impacts are much more frequent and constitute a constant threat to human and robotic operations on the surface.
When a meteoroid impacts the ground, most of its kinetic energy is suddenly converted into heat which partially vaporizes the impacting mass and scatters secondary debris all around the site. If an impact occurs where the surface is in umbra, it appears as bright flash, which can be detected by optical telescopes on the Earth. The intensity of the flashes can be measured to determine the kinetic energy of the meteoroid.
However, observations from Earth must be performed at nighttime and are often disturbed by atmospheric events. Moreover, only those impacts that occur on the observable face of the Moon can be detected.
On the contrary, LUMIO will have a constant and unobstructed view on the lunar far side from its orbit around the L2 Earth-Moon Lagrangian point. Since the observation periods (i.e., when the surface is in shadow) are opposite with respect to Earth, LUMIO will considerably increase the monitored portion of the Moon's surface. The measurements coming from the spacecraft, coupled with those from Earth, will provide a more detailed statistics about the probability and distribution of meteoroids impacts on the Moon.
Spacecraft
LUMIO will be a 12-U Cubesat with dimensions of 30x20x20 cm, having a maximum wet mass of 28 kg. The platform will be manufactured by Argotec, an Italian aerospace engineering company based in Turin. Argotec has previous experiences in deep-space CubeSats, having designed LICIACube, the companion of NASA's DART spacecraft, and Argomoon, one of the secondary payloads of the Artemis-1 mission.
The spacecraft will be equipped with a propulsion system in order to perform the space maneuvers needed to reach the final orbit and small station-keeping corrections.
Extendable solar arrays produced by IMT will provide enough power during all the phases of the mission. IMT will also manufacture the X-band transponder needed for establishing communications to the Earth and performing navigation routines.
Mission profile
Orbit
The L2 Lagrangian point is specific zone of equilibrium in the combined gravitational field of the Earth-Moon system. At the L2 point, the gravitational attractions of the two celestial objects are combined. Due to this, it exists a particular family of three-dimensional trajectories, called halo orbits, which a satellite can exploit to remain in the vicinity of the Moon without orbiting it.
The LUMIO spacecraft will fly on one of these trajectories, having the possibility of constantly observing the lunar far-side from a distance ranging between 36,000 and 86,000 km.
Mission phases
The LUMIO mission will be divided into four phases:
Parking phase. The spacecraft is launched as a secondary payload and gets released into selenocentric orbit by the carrier. During the 14 days of this phase the CubeSat will begin commissioning.
Transfer phase. LUMIO performs a stable manifold injection maneuver (SMIM) and begins the transfer towards the L2 point. This phase has a duration of 14 days.
Operative phase. The spacecraft executes the halo injection maneuver (HIM) and is inserted into the operational orbit. During this 1-year phase, LUMIO will perform all its scientific tasks and relay the data back to Earth. Multiple station-keeping maneuvers will take place to keep the satellite in the nominal trajectory.
End of life. At the end of the operative phase, LUMIO will perform a final maneuver for the safe disposal of the spacecraft.
Scientific payload
The LUMIO-Cam is the main scientific instrument of the LUMIO mission. It will be designed and manufactured by Leonardo, in their facilities of Campi Bisenzio (Florence). The camera will have a resolution of 1024 x 1024 pixels and will be able to acquire images in both the visual and near-infrared spectrums. The refresh rate will be of 15 frames per second in order to detect flashes with duration as fast as 30 ms.
The camera will have a focal length of 127 mm, obtaining a Field-Of-View of 6.0º. This angular size is just enough to perform full disk observations of the Moon, which has an apparent size of 5.6° at the closest point of the trajectory.
When more than 50% of the Moon's surface is illuminated, the glare deriving from the albedo is too intense for observing the flashes on the unlit portion. Due to this, the surface monitoring will be possible only 50% of the time, in 15-days time windows. The spacecraft will perform station-keeping maneuvers and secondary scientific activities while waiting for the next monitoring window.
The amount of data generated by the payload during the scientific phases is close to 5 TB/day. Since this value is too large to be transferred back to Earth, the images will be preliminarly processed on board. Only the images with detected impact flashes will be sent to the ground-stations, effectively reducing the required data transfer to approximately 1 MB/day.
Navigation experiment
The secondary objective of the LUMIO mission is to demonstrate the possibility of performing navigation routines in complete autonomy, without communicating with ground stations. The images from the LUMIO-Cam will be processed by optical navigation algorithms to provide an estimate of the position of the satellite with respect to the Moon. The technique that will be used is called full-disk navigation and It is expected to achieve an operational accuracy of less than 100 km.
With this technique each picture is processed to find the edges of the moon. Then, an ellipse is fitted to reconstruct the location of full lunar limb in the image. The fitted ellipse is the bi-dimensional projection of the three-dimensional Moon ellipsoid onto the image plane. Since the characteristics of the camera and the dimensions of the Moon ellipsoid are known, the ellipse points can be used as a state measurements in a Kalman filter.
See also
List of missions to the Moon
Near-Earth meteoroids
Asteroid impact
CubeSat
References
Space missions
Space exploration
Missions to the Moon
European Space Agency space probes
CubeSats | LUMIO (space mission) | [
"Astronomy"
] | 1,550 | [
"Space exploration",
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74,209,853 | https://en.wikipedia.org/wiki/Thermodynamic%20modelling | Thermodynamic modelling is a set of different strategies that are used by engineers and scientists to develop models capable of evaluating different thermodynamic properties of a system. At each thermodynamic equilibrium state of a system, the thermodynamic properties of the system are specified. Generally, thermodynamic models are mathematical relations that relate different state properties to each other in order to eliminate the need of measuring all the properties of the system in different states.
The easiest thermodynamic models, also known as equations of state, can come from simple correlations that relate different thermodynamic properties using a linear or second-order polynomial function of temperature and pressures. They are generally fitted using experimental data available for that specific properties. This approach can result in limited predictability of the correlation and as a consequence it can be adopted only in a limited operating range.
By contrast, more advanced thermodynamic models are built in a way that can predict the thermodynamic behavior of the system, even if the functional form of the model is not based on the real thermodynamic behaviour of the material. These types of models contain different parameters that are gradually developed for each specific model in order to enhance the accuracy of the evaluating thermodynamic properties.
Cubic model development
Cubic equations of state refer to the group of thermodynamic models that can evaluate the specific volume of gas and liquid systems as a function of pressure and temperature. To develop a cubic model, first, it is essential to select a cubic functional form. The most famous functional forms of this category are Redlich-Kwong, Soave-Redlich-Kwong and Peng-Robinson. Although their initial form is empirically suggested, they are categorised as semi-empirical models as their parameters can be adjusted to fit the real experimental measurement data of the target system.
Pure component modelling
In case the development of a cubic model for a pure component is targeted, the purpose would be to replicate the specific volume behaviour of the fluid in terms of temperature and pressure. At a given temperature, any cubic functional form results in two separate roots which makes us capable of modelling the behaviour of both vapour and liquid phases within a single model. Finding the roots of the cubic function will be done by simulating the vapour-liquid equilibrium condition of the pure component where the fugacity coefficients of the two phases are equal to each other.
So, in this case, the main aim can be limited to deriving fugacity coefficients of vapour and liquid phases from the cubic model and refining the adjustable parameters of the model such that they will become equal to each other at different equilibrium pairs of temperature and pressure. As the equilibrium pressure and temperature are related together in the case of a pure component system, the functional form of cubic models are able to evaluate the specific volume of the system in the wide range of temperature and pressure domain.
Multi-component modelling
Cubic model development for mixtures of more than one component is different as, according to the Gibbs phase rule, at each temperature level of a multi-component system, equilibrium states can exist at multiple pressure levels. Because of that, development of the thermodynamic model should be performed following different steps:
Selection of the cubic model: The initial step is the selection of a cubic functional form. Essentially, there exists no specific rule for this step. It can be done based on common practices of the cubic models already developed for the pure components existing in the mixture.
Single phase: Although a cubic model for a pure component is capable of predicting the specific volume of the system at both vapour and liquid phases, this is not the case for multi-component systems. Currently cubic models are used for the prediction of specific volume only in the vapour phase, while the liquid phase is modelled with more complex models based on the excess Gibbs energy, such as UNIFAC, UNIQUAQ, etc.
Vapour and liquid phases: Cubic models can be expanded to model multi-component systems at both vapour and liquid phases by integrating a proper mixing rule in their structural function.
Mixing rules
Mixing rules refer to different approaches that can be used to modify the cubic model in the case of multi-component mixtures. The simplest mixing rule is proposed by van der Waals and is called the van der Waals one fluid (vdW1f) mixing rule. As it can be understood from its name, this mixing rule is only used in case of modelling of a single phase (vapor phase). As a first step, to combine the model parameters for each binary combination of the mixture, the following equations are suggested:
where and are the parameters of the main target cubic model that was previously chosen. Then, all the possible binary combinations together with the concentration of each constituent in the mixture are used to define the final parameters for the mixture model as below:
In the case of using this mixing rule, except the two adjustable binary interaction parameters (BIPs) for each combination ( and ), other parameters are specified based on the pure component parameters and the concentration of different constituents in the mixture. So, the model developed in this case is limited to adjusting these two parameters such that the fugacity coefficients at different phases will be equal to each other at a certain temperature and pressure level. To overcome the limitation of the sole single-phase behaviour prediction in the case of using this mixing rule, other advanced mixing rules are developed. To predict the thermodynamic behaviour of the multi-component system in different phases, it is essential to build the energy function as a fundamental property of the system. Although this is mainly the case for the fundamental models, advanced mixing rules such as Huran-Vidal mixing rule and Wong-Sandler mixing rule are developed to adjust the parameters of the cubic models to contain these fundamental properties. This is usually done by building a mathematical structure capable of calculating the excess Gibbs energy of the system. It is generally built by two widely used approaches, namely UNIFAC and Non Random Two Liquid (NRTL) method. The choice of the proper mixing rule to be implemented in the target system can be done based on the inherent properties of the target system such as the polarity of different components, the reactivity of system's constituents with respect to each other, etc.
Fundamental model development
Fundamental models refer to a family of thermodynamic models that propose a mathematical form for one of the fundamental thermodynamic properties of the system, such as Gibbs free energy or Helmholtz free energy. The core idea behind this type of thermodynamic models is that, by constructing the fundamental property, it is possible to take advantage of thermodynamic relations that express different thermodynamic properties as the first or second-order derivatives of fundamental properties, with respect to pressure, temperature or density.
Helmholtz free energy models
For the development of Helmholtz free energy models, the idea is to associate different parameters that resemble different inter-molecular forces between system species. As a result, these models are referred to as multi-parameter models. Steps to develop a Helmholtz free energy model can be summarized as:
Helmholtz free energy of pure components: Like all the thermodynamic models, the first step is to build the Helmholtz free energy of pure constituents of a system. For well-known components, such as carbon dioxide and nitrogen, such functions are already established and reported in the literature. These can be used as the starting point to establish such models for multi-component systems.
Helmholtz free energy of binary mixtures: Helmholtz free energy of a multi-component system can be obtained from the weighted sum of the Helmholtz free energy of each binary combination of the system constituents. The binary Helmholtz free energy contains different terms that are taking into account various intermolecular forces that can exist based on the inherent of the two target components. Such models are developed for natural gas components through GERG-2008 thermodynamic model and EOS-CGfor the humid and combustion gas-like mixtures. The main advantages of these models are their generality, which makes them applicable to a wide range of pressure, temperature, and the whole concentration range of involved constituents.
Thermodynamic models criterions
A thermodynamic model predicts different properties with a certain level of accuracy. In fact, based on the functional form of the thermodynamic model and the real behaviour of the system some properties can be predicted with high accuracy level, while the other ones could not be predicted accurately enough to comply with different industrial needs. In this regard several criterions should be taken into account for the proper choice of thermodynamic model to be practical based on the targeted application.
Applicability
Although thermodynamic models are generally developed to predict thermodynamic properties in a wide range of temperatures and pressures, due to the lack of experimental data for different compounds in the full operational range, model accuracy varies by moving towards wider temperature and pressure ranges. When a model is targeted to be used in a specific application, the initial step is to identify the temperature and pressure at what the model is intended to be implemented. If the model is able to perform in the target operating window, the second step is to investigate whether the model can cover all the system constituents within the concentration ranges of interest or not. Fundamental models answered this ambiguity by covering the whole concentration range of the compounds that they involved. However, this is not the case for ad-hoc cubic model developments which may be considered in the specific range of concentration based on the application.
Robustness
Thermodynamic models should be robust and reliable, providing consistent results across different conditions and applications. They should be able to handle non-ideal behaviour, phase transitions, and complex interactions without significant loss of accuracy. Although some models are capable of taking into account the possible reactions between the system constituents, this is not the case for other simpler models that can only predict the behaviour of the system only in a specific phase. So, it is essential to identify the typical behaviour of the fluid in the target application to select and develop a proper model. However, in most engineering applications, developing a model that would be able to predict the thermodynamic properties of the system in different phases, critical regions and taking into account the possible reaction between systems is a necessity.
Accuracy
Based on the foundation that each thermodynamic model is built, the accuracy could vary not only for a specific property evaluation from different models but also for predicting different properties within a specific model itself. Cubic models are developed based on the phase equilibrium and as a result, they can predict the phase equilibrium of pure and multi-component systems within an acceptable accuracy level in case the model is fine-tuned to the experimental data of interest. However, this family of models is not accurate enough in predicting density and specific heat capacity as the two main thermodynamic properties that are of importance in most industrial applications. In the recent case, some corrections are suggested to enhance the accuracy of the cubic models for different properties, such as Peneloux translation for density prediction.
On the other hand, models that are developed based on fundamental properties such as Gibbs free energy or Helmholtz free energy, are generally capable of predicting a wider range of properties. As these models have a multiple number of adjustable parameters that fitted to different of experimental properties data, it makes them a pioneer when it comes to accuracy.
Computational speed
The model should be computationally efficient, especially for complex systems and large-scale simulations. The model's equations and algorithms should be designed to minimize computational time. This is especially important in cases where transient processes are targeted that thermodynamic properties change significantly over the transient time domain and computationally demanding models cannot satisfy industrial needs.
Availability
In certain applications, it may be important to consider the acceptance and implementation of a specific thermodynamic model within the industry. Industrial standards and guidelines can provide insights into the preferred models for specific processes. However, not all thermodynamic models are widely available in commercial software packages. This is especially the case for more complex fundamental models that despite their robustness, they are not still well-accepted by industry to their limited availability.
See also
Thermodynamic equilibrium
List of thermodynamic properties
Equation of state
Wong-sandler mixing rule
Combining rules
UNIFAC
NRTL
References
Thermodynamic models
Engineering thermodynamics
Equations of state | Thermodynamic modelling | [
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74,209,862 | https://en.wikipedia.org/wiki/Medical%20open%20network%20for%20AI | Medical open network for AI (MONAI) is an open-source, community-supported framework for Deep learning (DL) in healthcare imaging. MONAI provides a collection of domain-optimized implementations of various DL algorithms and utilities specifically designed for medical imaging tasks. MONAI is used in research and industry, aiding the development of various medical imaging applications, including image segmentation, image classification, image registration, and image generation.
MONAI was first introduced in 2019 by a collaborative effort of engineers from Nvidia, the National Institutes of Health, and the King's College London academic community. The framework was developed to address the specific challenges and requirements of DL applied to medical imaging.
Built on top of PyTorch, a popular DL library, MONAI offers a high-level interface for performing everyday medical imaging tasks, including image preprocessing, augmentation, DL model training, evaluation, and inference for diverse medical imaging applications. MONAI simplifies the development of DL models for medical image analysis by providing a range of pre-built components and modules.
MONAI is part of a larger suite of Artificial Intelligence (AI)-powered software called NVIDIA Clara. Besides MONAI, Clara also comprises NVIDIA Parabricks for genome analysis.
Medical image analysis foundations
Medical imaging is a range of imaging techniques and technologies that enables clinicians to visualize the internal structures of the human body. It aids in diagnosing, treating, and monitoring various medical conditions, thus allowing healthcare professionals to obtain detailed and non-invasive images of organs, tissues, and physiological processes.
Medical imaging has evolved, driven by technological advancements and scientific understanding. Today, it encompasses modalities such as X-ray, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), ultrasound, nuclear medicine, and digital pathology, each offering capabilities and insights into human anatomy and pathology.
The images produced by these medical imaging modalities are interpreted by radiologists, trained specialists in analyzing and diagnosing medical conditions based on the visual information captured in the images. In recent years, the field has witnessed advancements in computer-aided diagnosis, integrating Artificial intelligence and Deep learning techniques to automatize medical image analysis and assist radiologists in detecting abnormalities and improving diagnostic accuracy.
Features
MONAI provides a robust suite of libraries, tools, and Software Development Kits (SDKs) that encompass the entire process of building medical imaging applications. It offers a comprehensive range of resources to support every stage of developing Artificial intelligence (AI) solutions in the field of medical imaging, from initial annotation (MONAI Label), through models development and evaluation (MONAI Core), and final application deployment (MONAI deploy application SDK).
Medical data labeling
MONAI Label is a versatile tool that enhances the image labeling and learning process by incorporating AI assistance. It simplifies the task of annotating new datasets by leveraging AI algorithms and user interactions. Through this collaboration, MONAI Label trains an AI model for a specific task and continually improves its performance as it receives additional annotated images. The tool offers a range of features and integrations that streamline the annotation workflow and ensure seamless integration with existing medical imaging platforms.
AI-assisted annotation: MONAI Label assists researchers and practitioners in medical imaging by suggesting annotations based on user interactions by utilizing AI algorithms. This AI assistance significantly reduces the time and effort required for labeling new datasets, allowing users to focus on more complex tasks. The suggestions provided by MONAI Label enhance efficiency and accuracy in the annotation process.
Continuous learning: as users provide additional annotated images, MONAI Label utilizes this data to improve its performance over time. The tool updates its AI model with the newly acquired annotations, enhancing its ability to label images and adapt to specific tasks.
Integration with medical imaging platforms: MONAI Label integrates with medical imaging platforms such as 3D Slicer, Open Health Imaging Foundation viewer for radiology, QuPath, and digital slide archive for pathology. These integrations enable communication between MONAI Label and existing medical imaging tools, facilitating collaborative workflows and ensuring compatibility with established platforms.
Custom viewer integration: developers have the flexibility to integrate MONAI Label into their custom image viewers using the provided server and client APIs. These APIs are abstracted and thoroughly documented, facilitating smooth integration with bespoke applications.
Deep learning model development and evaluation
Within MONAI Core, researchers can find a collection of tools and functionalities for dataset processing, loading, Deep learning (DL) model implementation, and evaluation. These utilities allow researchers to evaluate the performance of their models. MONAI Core offers customizable training pipelines, enabling users to construct and train models that support various learning approaches such as supervised, semi-supervised, and self-supervised learning. Additionally, users have the flexibility to implement different computing strategies to optimize the training process.
Image I/O, processing, and augmentation: domain-specific APIs are available to transform data into arrays and different dictionary formats. Additionally, patch sampling strategies enable the generation of class-balanced samples from high-dimensional images. This ensures that the sampling process maintains balance and fairness across different classes present in the data. Furthermore, invertible transforms provided by MONAI Core allow for the reversal of model outputs to a previous preprocessing step. This is achieved by leveraging tracked metadata and applied operations, enabling researchers to interpret and analyze model results in the context of the original data.
Datasets and data loading: multi-threaded cache-based datasets support high-frequency data loading, public dataset availability accelerates model deployment and performance reproducibility, and custom APIs support compressed, image- and patched, and multimodal data sources.
Differentiable components, networks, losses, and optimizers: MONAI Core provides network layers and blocks that can seamlessly handle spatial 1D, 2D, and 3D inputs. Users have the flexibility to effortlessly integrate these layers, blocks, and networks into their personalized pipelines. The library also includes commonly used loss functions, such as Dice loss, Tversky loss, and Dice focal loss, which have been (re-)implemented from literature. In addition, MONAI Core offers numerical optimization techniques like Novograd and utilities like learning rate finder to facilitate the optimization process.
Evaluation: MONAI Core provides a comprehensive set of evaluation metrics for assessing the performance of medical image models. These metrics include mean Dice, Receiving operating characteristic curves, Confusion matrices, Hausdorff distance, surface distance, and occlusion sensitivity. The metric summary report generates statistical information such as mean, median, maximum, minimum, percentile, and standard deviation for the computed evaluation metrics.
GPU acceleration, performance profiling, and optimization: MONAI leverages a range of tools including DLProf, Nsight, NVTX, and NVML to detect performance bottlenecks. The distributed data-parallel APIs seamlessly integrate with the native PyTorch distributed module, PyTorch-ignite distributed module, Horovod, XLA, and the SLURM platform.
DL model collection: by offering the MONAI Model Zoo, MONAI establishes itself as a platform that enables researchers and data scientists to access and share cutting-edge models developed by the community. Leveraging the MONAI Bundle format, users can seamlessly and efficiently utilize any model within the MONAI frameworks (Core, Label, or Deploy).
AI-inference application development kit
The MONAI deploy application SDK offers a systematic series of steps empowering users to develop and fine-tune their AI models and workflows for deployment in clinical settings. These steps act as checkpoints, guaranteeing that the AI inference infrastructure adheres to the essential standards and requirements for seamless clinical integration.
Key components of the MONAI Deploy Application SDK include:
Pythonic framework for app development: the SDK presents a Python-based framework designed specifically for creating healthcare-focused applications. With its adaptable foundation, this framework enables the streamlined development of AI-driven applications tailored to the healthcare domain.
MONAI application package packaging mechanism: the SDK incorporates a tool for packaging applications into MONAI Application Packages (MAP). These MAP instances establish a standardized format for bundling and deploying applications, ensuring portability and facilitating seamless distribution.
Local MAP execution via app runner: the SDK provides an app runner feature that enables the local execution of MAP instances. This functionality empowers developers to run and test their applications within a controlled environment, allowing prototyping and debugging.
Sample applications: the SDK includes a selection of sample applications that serve as both practical examples and starting points for developers. These sample applications showcase different use cases and exemplify best practices for effectively utilizing the MONAI Deploy framework.
API documentation: the SDK is complemented by comprehensive documentation that outlines the available APIs and provides guidance to developers on effectively leveraging the provided tools and functionalities.
Applications
MONAI has found applications in various research studies and industry implementations across different anatomical regions. For instance, it has been utilized in academic research involving automatic cranio-facial implant design, brain tumor analysis from Magnetic Resonance images, identification of features in focal liver lesions from MRI scans, radiotherapy planning for prostate cancer, preparation of datasets for fluorescence microscopy imaging, and classification of pulmonary nodules in lung cancer.
In healthcare settings, hospitals have leveraged MONAI to enhance mammography reading by employing Deep learning models for breast density analysis. This approach reduce the waiting time for patients, allowing them to receive mammography results within 15 minutes. Consequently, clinicians save time, and patients experience shorter wait times. This advancement enables patients to engage in immediate discussions with their clinicians during the same appointment, facilitating prompt decision-making and discussion of next steps before leaving the facility. Moreover, hospitals can employ MONAI to identify indications of a COVID-19 patient's deteriorating condition or determine if they can be safely discharged, optimizing patient care and post-COVID-19 decision-making.
In the corporate realm, companies choose MONAI to develop product applications addressing various clinical challenges. These include ultrasound-based scoliosis assessment, Artificial intelligence-based pathology image labeling, in-field pneumothorax detection using ultrasound, characterization of brain morphology, detection of micro-fractures in teeth, and non-invasive estimation of intracranial pressure.
See also
Artificial intelligence in healthcare
Medical imaging
Deep learning
Image segmentation
Image registration
Image generation
References
Further reading
External links
Medical software
Free health care software | Medical open network for AI | [
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74,210,027 | https://en.wikipedia.org/wiki/T-MOS%20thermal%20sensor | TMOS is a type of thermal sensor consisting in a micromachined thermally isolated transistor fabricated using CMOS-SOI(Silicon on Insulator) MEMS(Micro electro-mechanical system) technology. It has been developed in the last decade by the Technion - Israel Institute of Technology. A thermal sensor is a device able to detect the thermal radiation emitted by an object located in the FOV(Field Of View) of the sensor. Infrared radiation ( IR ) striking the sensor produces a change in the temperature of the device that as a consequence generates an electric output signal proportional to the incident IR power. The sensor is able to measure the temperature of the object radiating thanks to the information contained in the impinging radiation, exploiting in this sense Stefan - Boltzmann law. TMOS detector has two important characteristics that make it different from others: it's an active and uncooled sensor.
Fabrication process
A TMOS detector consists in a mosaic structure composed of several sub-pixels, which are electrically connected in parallel or in series or in a mixed combination, and are thermally isolated. In each sub-pixels the sensitive element is the TMOS sensor, that is suspended in vacuum, fabricated in CMOS - SOI technology and dry released. The mosaic structure includes: the pixel frame, the suspended transistor, that absorbs IR radiation and that could also be embedded in an absorbing IR membrane which determine the thermal capacitance of the sensor, and two folding arms that determine the sensor thermal conductivity.
TMOS fabrication is based on built - in masks and dry bulk micromachining. In TMOS fabrication to the standard CMOS - SOI technology, used to produce MOS transistor, is added a MEMS post process necessary to realize the folded arms and the suspension of the transistor. In standard CMOS process there are several metallization layers. In TMOS production the upper ones, made in aluminum or copper, are used as built - in masks. Both metals are not affected by the fluorine plasma, used to dry etch silicon and interlevel dielectrics. The use of built- in mask grants high alignment accuracy and resolution while reducing fabrication costs. Final step of MEMS post process is the metal mask removal. This step is performed using standard wet etchant of aluminum or copper.
At present 130 nm CMOS - SOI technology implemented on 8 inch wafers is used to produce TMOS sensors, employing wafer level processing in standard CMOS facilities, allowing cost reduction and large production volumes.
Packaging
To improve sensor's performance and to protect it from the surrounding environment, especially from moisture, TMOS sensor are packaged under vacuum. The wafer-level production enables also wafer-level packaging, allowing the possibility to integrate optical windows and filters to improve their efficiency and widening their applicability.
TMOS package contains two devices: one "active", that sense and is exposed to external radiation, and another one "blind", that is shielded from the outside through an aluminum mirror deposited on the package.
Operating principle
The working principle of TMOS sensor provides that when thermal IR radiation is absorbed in the sensitive area heats up the TMOS causing a variation in its temperature. The temperature change produces a current or a voltage output signal proportional to the absorbed radiation.
TMOS performance depends on the transistor operating region and configuration: two terminals component, diode-like configuration, or three terminals component. Two terminals configuration is characterized by a grater thermal isolation. On the other side the three-terminal configuration has an higher internal voltage gain, given by the higher output resistivity.
Subthreshold region is the preferred one because avoids self heating effects and leads to higher sensitivity. Another reason to work in subthreshold region is that TMOS is an active device so requires a bias, however in this operating region the power consumption is lower than in other ones.
From a circuit point of view the produced TMOS signal can be modelled as a temperature dependent current source in parallel with the generator for small signal equivalent circuit. The value of is directly proportional to the drain source current variation with respect to TMOS operating temperature and to the temperature variation induced on the TMOS by the radiation absorbed from target object. This temperature has a direct dependence on the absorbing efficiency, the incident radiation power and on the thermal conductance of the sensor.
As mentioned in the previous section TMOS sensor package contains two devices, so the signal is read in a differential configuration. In this way the blind TMOS represents a reference relative to which the measure is done. This configuration is useful because allows to reject the common mode signal and reduce self heating effects.
Responsivity
The most important figure of merit of every kind of sensor is its responsivity. The responsivity is defined as the ratio between the output electrical parameters, both current or voltage, and the incident power on the detector. For TMOS sensor working in subthreshold region is 1,25 x 107 V/W.
TCC and TCV
TMOS sensitivity depends if the device is working in current or voltage mode. In current mode a bias voltage is applied, the current increases by an increment, which is the signal current. In the first case sensitivity corresponds to the temperature coefficient of current TCC, that is inversely proportional to drain source current and directly proportional to the derivative of drain source current respect to the operating temperature. In contrast, at voltage mode, where a bias current is applied, the voltage decreases by an increment, which is the voltage signal. In voltage mode the sensitivity is the temperature coefficient of voltage TCV and is inversely proportional to the voltage bias and directly proportional to the derivative of voltage respect to temperature for the considered operating temperature. TCC values above 4%/K are achieved working in the subthreshold region.
Advantages
TMOS thermal sensor presents several advantages compared to other thermal sensors such as thermopiles, bolometers, and also microbolometers, which have a very similar structure. Both thermopile and bolometer are passive detectors while microbolometers can also have an active structure, but the transistor used is a TFT (thin-film transistor).
The main advantages of using TMOS sensor are:
High sensitivity and responsivity due to the active working mode, and in particular biasing the transistor in subthreshold region.
Low power consumption, that makes it suitable for IOT and wearable applications.
High internal gain.
High reproducible and reliable fabrication process.
Low fabrication costs due to CMOS compatible fabrication process used.
Large volumes production, makes it suitable for consumer electronics.
Disadvantages
The main disadvantage is in the limited sensitivity compared with cooled IR detectors. Quantum photon detectors, for example, reach higher sensitivity but they need to work at cryogenic temperatures, so require a cooling system which consumes a lot of power.
Applications
Thermal sensors may have a lot of different applications. They respond to thermal IR radiation so their main application is for the production of thermal IR cameras. The other possible applications regard different fields from gas analysis, human detection for autonomous driving, presence detection, people counting, security system, or thermal monitoring during the fabrication process.
Until now the main TMOS application has been as a high-sensitivity detector for motion and presence. When an object enters the FOV of the sensor there is a change in the radiation power that reaches the detector. This changing cause a temperature variation concerning the previous case and so coming from this difference the presence or motion is detected. This changing cause a temperature variation respect to previous case and so coming from this difference the presence or motion is detected. TMOS presence commercial products are available.
The low power consumption typical of the TMOS sensor means that it can also be powered by a common ion battery, making it suitable for IOT, wearable devices, mobile phone integration, and smart homes.
The human body emitted radiation falls in the mid-infrared range peaking around 12 μm, so one of the applications of thermal sensors is fever detection. TMOS high performance, in terms of high sensitivity and low power consumption, and low costs fabrication process make it a promising candidate to implement contactless thermometer.
See also
Bolometer
CMOS
Infrared radiation
MOSFET
Semiconductor fabrication process
Thermal radiation
Thermopile
References
Further reading
External links
How Semiconductors and Transistors work
Infrared Waves
Semiconductor Glossary
Measuring instruments
Transducers
Microelectronic and microelectromechanical systems
Microtechnology
Radiometry
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74,213,354 | https://en.wikipedia.org/wiki/Huygens%20principle%20of%20double%20refraction | Huygens principle of double refraction, named after Dutch physicist Christiaan Huygens, explains the phenomenon of double refraction observed in uniaxial anisotropic material such as calcite. When unpolarized light propagates in such materials (along a direction different from the optical axis), it splits into two different rays, known as ordinary and extraordinary rays. The principle states that every point on the wavefront of birefringent material produces two types of wavefronts or wavelets: spherical wavefronts and ellipsoidal wavefronts. These secondary wavelets, originating from different points, interact and interfere with each other. As a result, the new wavefront is formed by the superposition of these wavelets.
History
The systematic exploration of light polarization began during the 17th century. In 1669, Rasmus Bartholin made an observation of double refraction in a calcite crystal and documented it in a published work in 1670. Later, in 1690, Huygens identified polarization as a characteristic of light and provided a demonstration using two identical blocks of calcite placed in succession. Each crystal divided an incoming ray of light into two, which Huygens referred to as "regular" and "irregular" (in modern terminology: ordinary and extraordinary). However, if the two crystals were aligned in the same orientation, no further division of the light occurred.
Huygens–Fresnel principle
While the Huygens' principle of double refraction explains the phenomenon of double refraction in an optically anisotropic medium, the Huygens–Fresnel principle pertains to the propagation of waves in an optically isotropic medium. According to the Huygens–Fresnel principle, each point on a wavefront can be considered a secondary point source of waves, so a new wavefront is formed after the secondary wavelets have traveled for a period equal to one vibration cycle. This new wavefront can be described as an envelope or tangent surface to these secondary wavelets. Understanding and forecasting the classical wave propagation of light is based on the Huygens-Fresnel principle.
Polarization of light
Electric and magnetic fields that are mutually perpendicular and fluctuating give rise to the transverse electromagnetic wave known as light. Electric and magnetic fields are perpendicular to the propagation direction of the wave. For example, if the wave propagation is in the z-direction, both the electric field and the magnetic field lie in the xy-plane. The electric field points in a specific direction in space since it is a vector. The direction of an electromagnetic wave's electric field vector E is referred to as polarization. If the electric field oscillates in the x-direction, the polarization of the light will be linear, along the x-direction.
Plane wave equation of the light
The electromagnetic wave equation's sinusoidal solution has the following form:where
is time (in seconds),
is the angular frequency (in radians per second),
is the phase angle constant (in rad), and
is the wave vector of the wave (in rad/m).
The wave vector is related to the angular frequency and speed of light by
where is the wavenumber (the magnitude of the wave vector) and is the wavelength.
Unpolarized light
If we were able to observe a light wave originating from an ordinary source and directed toward us, such as the light emitted by an incandescent bulb, we would find that it consists of mixture of light waves. These waves exhibit electric field components that fluctuate at a rapid pace, nearly matching the optical frequency itself, with a time scale of approximately 10−14 seconds. Consequently, the direction of oscillation of the electric field vector occurs in all possible planes perpendicular to the direction of the light beam. Unpolarized light is a type of light wave where the electric field vector oscillates in multiple planes. Light emitted by the sun, incandescent lamps, or candle flames is considered to be unpolarized.
Types of polarization
The light wave polarization specifies the form and location of the electric field vector's direction at a particular point in space as a function of time (in the plane perpendicular to the propagation direction). There are three possible polarization states for light, depending on where the vector's direction is located. The first is plane or linear polarization, the second is elliptical polarization, and the third is circular polarization.
The light may also be partially polarized in addition to these. The polarization of light cannot be determined by the human eye on its own. However, some animals and insects have a vision that is sensitive to polarization.
Plane linear polarized light
Light waves that exhibit oscillation in a single plane are referred to as plane-polarized light waves. In such waves, the electric field vector (E) oscillates exclusively within a single plane that is perpendicular to the direction of wave propagation. This type of wave is also called a linearly polarized wave since the orientation of the field vector at any given point in space and time lies along a line within a plane perpendicular to the wave's direction of propagation.
Isotropic and anisotropic materials
Materials can be classified into two categories based on their isotropy. Materials that are isotropic have the same physical characteristics throughout. In other words, regardless of the direction in which they are measured, their characteristics, such as optical, electrical, and mechanical, stay constant. Gases, liquids, and amorphous solids like glass are instances of isotropic materials. On the other hand, anisotropic materials show various physical characteristics depending on the direction of measurement. Their characteristics are not constant throughout the substance. Crystal structure, molecule orientation, or the presence of preferred axes can all be causes of anisotropy. Crystals, certain polymers, calcite, and numerous minerals are typical examples of anisotropic materials. The physical characteristics of anisotropic materials, such as refractive index, electrical conductivity, and mechanical qualities, can differ depending on the direction of measurement.
Optical axis and types of anisotropic materials
A frequent notion in the study of anisotropic materials, particularly in the context of optics, is the optical axis. It refers to a particular axis within the material along which certain optical characteristics remain unaltered. To put it in another way, the light that travels along the optical axis does not experience anisotropic behaviours on the transverse plane.
It is possible to further divide anisotropic materials into two categories: uniaxial anisotropic and biaxial anisotropic materials. One optical axis, also referred to as the extraordinary axis, exists in uniaxially anisotropic materials. In these materials, light propagating along the optical axis experience the same effects independently of the polarization. The optical plane, also known as the plane of polarization, is perpendicular to the optical axis. Light exhibits birefringence within this plane, which means that the refractive index and all the phenomena associated to that, depend on the polarization. A common effect that can be observed is the splitting of an incident ray into two rays when propagating in a birefringent medium. Due to the presence of two independent optical axes in biaxial anisotropic materials, light travelling in two different directions will experience different optical characteristics.
Positive and negative uniaxial material
There are two types of uniaxial material depending on the value of index of refraction for the e-ray and o-ray. When the value of the refractive index of the e-ray (ne) is larger than the index of refraction index of the o-ray(n0), the material is positive uniaxial. On the other hand, when the value of refractive index of the e-ray (ne) is less than index of refraction index of the o-ray (n0), the material is negative uniaxial material. Ice and quartz are examples for positive uniaxial material. Calcite and tourmaline are examples of negative uniaxial materials.
Huygens' explanation of double refraction
The ordinary ray (o-ray) has a spherical wavefront because the o-ray has a constant refractive index (n0) independent of propagation direction inside the uniaxial material and the same velocity in all directions. On the other hand, the extraordinary ray (E-ray) has an ellipsoidal wavefront due to its refractive index, which varies with the propagation direction within the uniaxial material, leading to different velocities in different directions. The two wavefronts come into contact at the points where they intersect with the optical axis.
When unpolarized light incidents on the birefringent material, the o-ray and e-ray will generate new wavefronts. The new wavefront for the o-ray will be tangent to the spherical wavelets, while the new wavefront for the e-ray will be tangent to the ellipsoidal wavelets. Each plane wavefront propagates straight ahead but with different velocities: V0 for the o-ray and Ve for the e-ray. The direction of the k-vector is always perpendicular to the wavefronts and is calculated from Snell's law. For normal incidence, the o-ray and e-ray having the same k-vector direction. However, the Poynting vector, describing the direction of propagation of optical power, is different for the two rays. The power direction for each ray is determined by connecting the line from the imaginary source on the old wavefront to the intersection point between the new wavefront and the spherical or ellipsoidal wavefront. As a result, the o-ray and e-ray will propagate in different directions with different velocities inside the material. For the e-ray, the angle between the k-vector and the power direction is called walk-off angle.
When a light travels through the crystal, these two wave surfaces follow distinct paths within the crystal. Eventually, two refracted rays emerge as a result of this propagation.
See also
Double refraction
Electromagnetic wave equation
Huygens–Fresnel principle
Isotropy
Polarization
Poynting vector
Wave vector
References
External links
Refraction
Optics
Polarization (waves) | Huygens principle of double refraction | [
"Physics",
"Chemistry"
] | 2,163 | [
"Physical phenomena",
"Applied and interdisciplinary physics",
"Refraction",
"Optics",
"Astrophysics",
"Optical phenomena",
" molecular",
"Atomic",
"Polarization (waves)",
" and optical physics"
] |
74,213,591 | https://en.wikipedia.org/wiki/NGC%205135 | NGC 5135 is a barred spiral galaxy located in the constellation Hydra. It is located at a distance of about 200 million light years from Earth. It was discovered by John Herschel on May 8, 1834. It is a Seyfert galaxy.
Characteristics
NGC 5135 has well defined spiral arms and is considered a grand design spiral galaxy. There is star formation along the leading edges of the arms. There are dust lanes along the bar that curve towards the centre of galaxy. Spiral arms become less well structured in the central regions.
NGC 5135 is a bright source in infrared light and with total infrared luminosity of − is considered a luminous infrared galaxy. Also strong ultraviolet emission was detected in the central 2 arcseconds of the galaxy, with a dozen of prominent knots, indicative of a recent starburst. The total star formation rate in the galaxy is estimated to be 15.61 ± 1.87 per year. Knots of gas measuring 45–180 parsecs across are detected along the inner spiral arms in CO(6-5) imaging and some of them are associated with starburst regions.
The nucleus of NGC 5135 has been found to be active and it has been categorised as a type II Seyfert galaxy. The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole. The mass of the black hole in the centre of NGC 5135 is estimated to be 107.29 (19 million) .
The active nucleus is obscured in X-rays by Compton-thick material with a column density of /cm2. An ionization cone has been detected in [Si vi] emission that extends for 600 parsec from the nucleus. To the ionization of the gas apart from the active nucleus also contribute supernova remnant shocks and young stars.
One supernova has been observed in NGC 5135: SN 2023dpj (type II, mag. 17).
Nearby galaxies
NGC 5135 belongs to a galaxy group known as LGG 351 or NGC 5135 group. Other members of the group include ESO 444- 12, NGC 5124, IC 4248, NGC 5150, NGC 5152, NGC 5153, IC 4275, NGC 5182, ESO 444- 47, ESO 444- 15, ESO 444- 21 and IC 4251, along with NGC 5126. IC 4248, which lies 13.5 arcminutes from NGC 5135 and form a pair, looks distorted and asymmetrical.
See also
NGC 1241 and NGC 7469 - Seyfert galaxies with circumnuclear star formation ring
References
External links
NGC 5135 on SIMBAD
Barred spiral galaxies
Seyfert galaxies
Luminous infrared galaxies
Hydra (constellation)
5135
46974
Discoveries by John Herschel
Astronomical objects discovered in 1834 | NGC 5135 | [
"Astronomy"
] | 597 | [
"Hydra (constellation)",
"Constellations"
] |
68,380,748 | https://en.wikipedia.org/wiki/DOMELRE | DOMELRE (an acronym of Domestic Electric Refrigerator) was one of the first domestic electrical refrigerators, invented by Frederick William Wolf Jr. (1879–1954) in 1913 and produced starting in 1914 by Wolf's Mechanical Refrigerator Company in Chicago. Several hundred units were sold, which made it the most commercially successful product out of several competing designs of its time. The unit replaced the block of ice in the icebox with an electrical-powered cooling device, and was completely automatic.
Often labelled as the "first electrical refrigerator" or similar, It has been described as "revolutionary" in the history of domestic refrigeration.
History
DOLMERE was invented by Frederick William Wolf Jr. (American engineer also known as Fred W. Wolf Jr., 1879-1954), a charter member of the American Society of Refrigerating Engineers, in 1913. An estimated several hundred to thousands of units were produced starting in 1914 by his Mechanical Refrigerator Company in Chicago. Fred Heideman was also involved in the unit's design. In 1916 Wolf sold the rights to the invention to Henry Joy, president of Packard Motor Car Company in Detroit, which released an upgraded version under the name ISKO. Having sold about a thousand more models, Joy's company nonetheless went bankrupt in 1922.
Commercially, DOMELRE was described as "a quick hit". The unit was considered relatively inexpensive for its time. The original model was sold for $900 ($24,450 in 2021 dollars); the 1916 model was priced at $385 in 1916 ($9,600 in 2021 dollars), later dropping to $275 ($6,850 in 2021 dollars). 525 were sold.
Significance
DOMELRE has been described as "revolutionary" in the history of domestic refrigeration. It has been described as the "first domestic refrigerator", the "first household refrigerator", the "first electrical refrigerator", the "first successful, mass marketed package automatic electric refrigeration unit", "the first plug-in refrigeration unit", "the first mass-produced small refrigeration system", "the first electric household refrigerator to survive its infancy" or just as "the domestic electric refrigerator".
According to ASHRAE, DOMELRE contained a number of innovations not found in prior domestic refrigerators, such as offering automatic temperature control by thermostat, an air cooled condenser that did not require water, and not the least, it also introduced a freezing tray for ice cubes.
A 2005 assessment of the history of the ice delivery business in the New York Times concluded that the technology that DOMELRE pioneered gradually led to the end of that business in New York by 1950.
References
External links
US patents for Fred W. Wolf including for his "refrigerating apparatuses"
Products introduced in 1913
Cooling technology
American inventions
Food preservation
Home appliances | DOMELRE | [
"Physics",
"Technology"
] | 588 | [
"Physical systems",
"Machines",
"Home appliances"
] |
68,380,880 | https://en.wikipedia.org/wiki/1%2C2-Bis%28diphenylphosphino%29ethylene | cis-1,2-Bis(diphenylphosphino)ethylene (dppv) is an organophosphorus compound with the formula C2H2(PPh2)2 (Ph = C6H5). Both the cis and trans isomers are known, but the cis isomer is of primary interest. Classified as a diphosphine ligand, it is a bidentate ligand in coordination chemistry. For example it gives rise to the complex Ni(dppv)2 and the coordination polymer [Ni(dppv)]n. As a chelating ligand, dppv is very similar to 1,2-bis(diphenylphosphino)benzene.
The diphosphine is prepared by reaction of lithium diphenylphosphide with cis-dichloroethylene.
2LiPPh2 + C2H2Cl2 → C2H2(PPh2)2 + 2LiCl
trans-1,2-Bis(diphenylphosphino)ethylene is made similarly, but using trans-dichloroethylene.
References
Chelating agents
Diphosphines
Phenyl compounds | 1,2-Bis(diphenylphosphino)ethylene | [
"Chemistry"
] | 250 | [
"Chelating agents",
"Process chemicals"
] |
68,381,216 | https://en.wikipedia.org/wiki/Moshio%20salt | Moshio salt () is a type of Japanese sea salt made using an ancient method where it is collected using a dried seaweed known as hondawara (Sargassum fulvellum). The seaweed is believed to confer additional umami flavor to the salt.
Japan's climate is too cool and wet to allow easy production of salt by simple evaporation of seawater. Boiling down seawater directly used a tremendous amount of fuel, so seaweed was historically the main technique used until the 7th century when enden pan salt – clay pan salt fields – became the main salt production technique.
Process
To make the salt, the seaweed is dried out, and salt crystals form on the seaweed. These are collected by boiling the seaweed in seawater in bags to form a concentrated brine. The resultant solution is boiled down until it crystallizes out.
References
Edible salt | Moshio salt | [
"Chemistry"
] | 184 | [
"Edible salt",
"Salts"
] |
68,381,819 | https://en.wikipedia.org/wiki/Ibn%20Hibinta | Ibn Hibintā (fl. 950) was a Christian in Iraq known from an Arabic manuscript on Islamic astrology al-Mughnī fī aḥkām al-nujūm, the second part of which is preserved in Munich.
Hibinta's lived during the reign of the Buwayhid rulers Ahmad ibn Buwayh (946–949) and ʿAḍūd al-Dawla (949–982) at Baghdad. His only known work, the Kitab al-Mughnī fī aḥkām al-nujūm (literally, the enriching book of the judgement of the stars) includes notes from Ptolemy, Dorotheus of Sidon, al-Khwarizmi and the Indian astrologer Kanaka. A manuscript copy of the second part is held as Arabic Codex 852 at the Bayerische Staatsbibliothek, Munich.
References
Astrologers of the medieval Islamic world
Arab astronomers
Scholars under the Buyid dynasty
Christian astrologers
Christians under the Buyid dynasty | Ibn Hibinta | [
"Astronomy"
] | 214 | [
"Astronomers",
"Arab astronomers"
] |
68,382,558 | https://en.wikipedia.org/wiki/Good%20Design%20Award%20%28Japan%29 | The Good Design Award () is an award sponsored by the Japan Institute of Design Promotion, which is given to things with excellent design every year. It is the only comprehensive evaluation and recommendation system of design in Japan.
The Chicago Athenaeum also sponsors an annual Good Design Award which is unrelated to the Japanese award.
References
External links
Design awards
Japanese awards | Good Design Award (Japan) | [
"Engineering"
] | 71 | [
"Design",
"Design awards"
] |
68,382,914 | https://en.wikipedia.org/wiki/Pigcasso | Pigcasso (April 2016 – March 2024) was a pig from South Africa whose paintings have sold for millions of rand all over the world. Pigcasso is best known for being the first non-human artist to be given her own art exhibition, and for holding the record for most expensive artwork by an animal ever sold. She is also famous for the watchmaker Swatch using one of her paintings in its 2019 limited-edition Flying Pig timepiece. More broadly, she was known for inspiring conversations around veganism, vegetarianism, and factory farming.
Life
Early life
Pigcasso was a female pig (Sus domesticus) born in April 2016 on an industrialised pig farm in the Winelands region of the Western Cape, South Africa. Along with her sister Rosie, she was rescued from a slaughterhouse, in May, by Joanne Lefson and taken to Farm Sanctuary SA in Franschhoek, the nonprofit animal sanctuary that Lefson founded that year. Lefson is a former professional golfer who briefly dated John Denver and travelled the world with Oscar, a dog she adopted and married, but later accidentally ran over, which it did not survive.
Art career
When Lefson noticed that the pig ate and destroyed everything in her stall besides some paint brushes, she employed clicker training and positive reinforcement techniques to teach the pig to hold the brush in her mouth and apply paint to paper mounted on an easel placed before her. By dipping the brush in different colors, the pig began to create colorful abstract paintings in October 2016, which Lefson then sold to raise funds for the sanctuary. Each of Pigcasso's works was signed by dipping her nose-tip into beetroot ink and touching it onto the canvas.
Pigcasso and Lefson were the first non-human/human collaboration to have held an art exhibition together, OINK, which took place at the V&A Waterfront in Cape Town in 2018. Subsequently, Pigcasso's works were displayed in art exhibitions in the Netherlands (2021); Germany (2022); the UK (2023); and China (2023/24). Pigcasso's artworks have been described as Abstract expressionism and have sold for millions of rand to collectors around the world. Three of her most famous pieces are Penguin, Snowman, and Mouse, each of which sold for $5,000 in 2021. A painting of Prince Harry that was sold to a Spanish buyer for £2,350 in 2021 also received global notoriety, because of its subject. Works by Pigcasso have been held by Jane Goodall, Rafael Nadal, Ed Westwick, and George Clooney. On 13 December 2021, a work by Pigcasso sold for £20,000, a record price for an artwork created by an animal. The canvas, titled Wild and Free, was purchased by German art collector Peter Esser, eclipsing the £14,000 American collector Howard Hong paid for a painting by Congo the chimpanzee. By the time of her death, Lefson had sold over $1 million worth of Pigcasso's paintings, with proceeds going towards the upkeep of the sanctuary where she lived.
The relationship between Pigcasso and Lefson has been noted for igniting debate around the definition of art and animal creativity, while also drawing attention to the living conditions of farm animals around the world. Lefson stated that her aim is to educate the public about the devastating effects of animal husbandry on the welfare of animals and the environment in order to inspire a kinder, more sustainable world.
Media
The watchmaker Swatch commissioned an artwork of Pigcasso's for a 2019 watch called Flying Pig. She was also featured in the 60th anniversary advertisement of the Nissan Skyline (2017), and in 2020, a "Pigcasso" range of wine, produced from the grapes that grow at the farm sanctuary where she lived, was launched.
Over the course of her life, Pigcasso was featured on various global media channels. Her exploits were covered on Saturday Night Live, ABC, NBC, CBS, CNN, National Geographic, Sky News, and the BBC. Pigcasso also appeared live on The Jeremy Vine Show in 2020 and in publications such as The Times newspaper and Der Spiegel. In August 2023, a book about Pigcasso’s life was released in London, titled Pigcasso. The Pig That Saved a Sanctuary, which includes a foreword by Jane Goodall.
Illness and death
Pigcasso had chronic rheumatoid arthritis, which calcified her spine. Her condition deteriorated rapidly in September 2023 and by October her hind legs were nearly non-functional. On 6 March 2024, Lefson announced that Pigcasso had died. Among Pigcasso's many admirers, Dr Jane Goodall was present to pay her respects the day after she died. Goodall flew out to the sanctuary after hearing about the pig's condition, but arrived one day too late, with Pigcasso passing away before the two had a chance to formally meet. The next day, Goodall shared a tribute for the pig at a gala hosted by the sanctuary, raising R300,000 (or USD16,062) for her non-profit organisation.
Notes
References
External links
Pigcasso official website
Farm Sanctuary SA official website
Joanne Lefson official website
2016 animal births
2024 animal deaths
Individual pigs
Veganism
Animal rights
Individual animals in South Africa
Visual arts by animals
Deaths from arthritis
Abstract expressionist artists | Pigcasso | [
"Biology"
] | 1,137 | [
"Ethology",
"Behavior",
"Animals",
"Visual arts by animals"
] |
68,384,883 | https://en.wikipedia.org/wiki/Vujica%20Jev%C4%91evi%C4%87 | Vujica Jevđević (Vujica M. Yevjevich) (12 October 1913 – 26 March 2006) was a Yugoslav hydrologist and educator.
He was the founder and the first director of the Hydroenergetic Institute in Belgrade and the Hydraulic Laboratory, institutions that led the construction of hydroelectric power plants in post-WW2 Yugoslavia. In the US, Jevđević was the director of the International Water Resources Institute at George Washington University and professor in the engineering department at Colorado State University.
Biography
Jevđević graduated from the University of Belgrade before doing a specialisation in hydrology at the University of Grenoble. During World War 2 he was a war prisoner of the Axis troops, and in 1944 he successfully returned to the liberated Belgrade and joined the newly formed Ministry of Construction. He led the establishment of the new institutes for and hydroenergy, and returned to the University of Belgrade as a lecturer. There he defended his doctoral thesis in 1955 as Yugoslavia's first doctor in hydrology..
In the following years, he was a visiting scientist for the U.S. National Bureau of Standards and for the U.S. Geological Survey in Washington, D.C. before taking the professorial post at Colorado State University where he taught hydro-engineering. He was also the Director of the International Water Resources Institute at George Washington University in Washington, D.C. Jevđević won many awards during his prolific academic career, including the inaugural 1996 Ven Te Chow Award of ASCE, inaugural 1988 Ven Te Chow Award of IWRA, as well as IAHS International Hydrology Award in 1987
Jevđević died in 2006 after a long battle with Parkinson's disease.
At the time of his death, he was finishing a seven-volume autobiography.
References
1913 births
2006 deaths
Yugoslav scientists
Hydrologists
Neurological disease deaths in Colorado
Deaths from Parkinson's disease
People from Priboj
George Washington University faculty
Yugoslav emigrants to the United States
Colorado State University faculty
University of Belgrade alumni
World War II prisoners of war
Serbian people of World War II | Vujica Jevđević | [
"Environmental_science"
] | 425 | [
"Hydrology",
"Hydrologists"
] |
68,386,230 | https://en.wikipedia.org/wiki/List%20of%20environmental%20sampling%20techniques | Environmental sampling techniques are used in biology, ecology and conservation as part of scientific studies to learn about the flora and fauna of a particular area and establish a habitat's biodiversity, the abundance of species and the conditions in which these species live amongst other information. Where species are caught, researchers often then take the trapped organisms for further study in a lab or are documented by a researcher in the field before the animal is released. This information can then be used to better understand the environment, its ecology, the behaviour of species and how organisms interact with one another and their environment. Here is a list of some sampling techniques and equipment used in environmental sampling:
Quadrats - used for plants and slow moving animals
Techniques for Birds and/or Flying Invertebrates and/or Bats
Malaise Trap
Flight Interception Trap
Harp Trap
Robinson Trap
Butterfly Net
Mist Net
Techniques for Terrestrial Animals
Transect
Tullgren Funnel - used for soil-living arthropods
Pitfall Trap - used for small terrestrial animals like insects and amphibians
Netting techniques for terrestrial animals
Beating Net - used for insects dwelling in trees and shrubs
Sweep Netting - used for insects in grasses
Aspirator/Pooter - used for insects
Camera Trap - used for larger animals
Sherman Trap - used for small mammals
See also
Insect Collecting
Wildlife Biology
Sampling
Sources
Scientific method
Survey methodology
Scientific observation
Biological techniques and tools | List of environmental sampling techniques | [
"Biology"
] | 270 | [
"nan"
] |
68,386,378 | https://en.wikipedia.org/wiki/C/2021%20O3%20%28PanSTARRS%29 | C/2021 O3 (PanSTARRS) is perhaps an Oort cloud comet, discovered on 26 July 2021 by the Pan-STARRS sky survey. It came to perihelion on 21 April 2022 at . from the Sun.
The comet was expected to reach apparent magnitude 5 by late April 2022, while being only 15 degrees from the Sun. While near perihelion the comet was dimmer than expectations. It was faintly visible in STEREO/SECCHI COR2-A on 27 April 2022. Observations by Lowell Discovery Telescope on April 29 in the twilight detected a diffuse glow with a magnitude of 9 where the comet was expected to be, indicating that the comet nucleus disintegrated during perihelion. C/2021 O3 made its closest approach to Earth on 8 May 2022 at a distance of . As a dynamically new comet from the Oort cloud there was a high risk of disintegration.
The comet was recovered by multiple observatories after perihelion at magnitudes not too different from those observed pre-perihelion. Calculations carried out using the pre- and post-perihelion orbits indicate that although the comet is probably dynamically old, it may also be a fragment of a dynamically new comet that was released during the first perihelion passage of its parent comet.
Orbit
With a short observation arc of 7 days, the Minor Planet Center used an assumed eccentricity of 1.0 for the orbit solution. Due to statistics of small numbers, with a short 10 day arc JPL had an eccentricity of which could be as high as 1.00039 or as low as 0.99151. With an observation arc of 53 days, JPL Horizons shows both an inbound and outbound eccentricity greater than 1.
C/2021 O3 probably took millions of years to arrive from the outer Oort cloud and, had it survived, may have been fated to be ejected from the Solar System. This is also the most likely scenario when considering the post-perihelion orbit determination of the surviving object.
References
External links
Non-periodic comets
Discoveries by Pan-STARRS
20210726
Oort cloud
Hyperbolic comets
Destroyed comets
Comets in 2021
Comets in 2022 | C/2021 O3 (PanSTARRS) | [
"Astronomy"
] | 466 | [
"Astronomical hypotheses",
"Oort cloud"
] |
68,388,430 | https://en.wikipedia.org/wiki/Pixel%206 | The Pixel 6 and Pixel 6 Pro are a pair of Android smartphones designed, developed, and marketed by Google as part of the Google Pixel product line. They collectively serve as the successor to the Pixel 5. The phones were first previewed in August 2021, confirming reports that they would be powered by a custom system-on-chip named Google Tensor. The cameras are housed in a horizontal bar on the back, while the front features a hole-punch display notch in the center. They shipped with Android 12, with Google announcing numerous artificial intelligence and ambient computing features during the phones' launch event.
The Pixel 6 and Pixel 6 Pro were officially announced on October 19, 2021, at the Pixel Fall Launch event, and were released in the United States on October 28, following an extensive marketing campaign. They received generally positive reviews from critics, who praised its Tensor chip, cameras, performance, design, and price, though the fingerprint sensor and battery life received mixed reactions. The phones became Google's fastest-selling Pixel devices, allowing the company to become the fifth-largest smartphone manufacturer in North America and the United Kingdom during the first quarter of 2022. They were succeeded by the Pixel 7 and Pixel 7 Pro in 2022.
History
The Pixel 6 and Pixel 6 Pro were previewed by Google on August 2, 2021, confirming the phones' new designs and the introduction of its custom Tensor system-on-chip (SoC). Previous Pixel devices had used Qualcomm Snapdragon chips, with Google having begun developing its own chips codenamed Whitechapel as early as April 2016. The devices were approved by the Federal Communications Commission (FCC) in September. Google officially announced the phones on October 19, 2021, at the Pixel Fall Launch event, and they became available in nine countries on October 28. The phones were manufactured by Foxconn, and were originally intended to be produced in Vietnam before shifting back to China due to the Chinese government's stringent border controls imposed in response to the COVID-19 pandemic. Google doubled the production of its phones compared to last year in attempt to boost its market share, manufacturing approximately seven million devices. The phones were not made available in India at launch due to supply chain issues.
During the launch event, Google also announced the phones' official cases, which became available for pre-order on the same day with three color options for the Pixel 6 and four color options for the Pixel 6 Pro, as well as the second-generation Pixel Stand wireless charger, which went on sale on November 18 and began shipping on December 13. Pre-orders for the phones began on the same day as the announcement, with shipping commencing on October 25. The Google Store did not offer any discounts for the devices on Black Friday, a departure from prior years. In February 2022, the Pixel 6 and Pixel 6 Pro became available in Italy and Spain in "limited quantities", with a limited launch in Singapore two weeks later.
Specifications
Design
The Pixel 6 and Pixel 6 Pro both feature a unique design that is visually distinct from previous-generation Pixel phones, including a large camera bar and two-tone color scheme on the back. The front of both phones also feature a centered hole-punch display notch. They are each available in three colors:
Hardware
The Pixel 6 has a FHD+ 1080p OLED display at 411 ppi with a pixel resolution and a 20:9 aspect ratio, while the Pixel 6 Pro has a QHD+ 1440p LTPO OLED curved edges display at 512 ppi with a pixel resolution and a 19.5:9 aspect ratio. Both displays have HDR10+ support; the Pixel 6 has a 90 Hz refresh rate and the Pixel 6 Pro has a 120 Hz variable refresh rate. Both phones contain a 50 megapixel wide rear camera and a 12 megapixel ultrawide rear camera, with the Pixel 6 Pro featuring an additional 48 megapixel 4× optical zoom telephoto rear camera. The front camera on the Pixel 6 contains an 8 megapixel wide lens, while the one on the Pixel 6 Pro contains an 11.1 megapixel ultrawide lens. The new Tensor chip also brought Live HDR+ to video as well as enhancements to the Night Sight and Super Res Zoom features on the devices.
The Pixel 6 has a 4614 mAh battery, while the Pixel 6 Pro has a 5003 mAh battery. Both phones support fast charging, Qi wireless charging, as well as reverse wireless charging. The Pixel 6 is available in 128 or 256 GB of storage and 8 GB of RAM, and the Pixel 6 Pro is available in 128, 256, or 512 GB of storage and 12 GB of RAM. In addition to the Tensor chip, both phones are also equipped with the Titan M2 security module, which is based on the RISC-V open standard, along with an under-display optical fingerprint scanner, stereo speakers, and Gorilla Glass Victus. In April 2022, 9to5Google reported that the Pixel 6 Pro was originally planning to be launched with a Face Unlock facial recognition feature, similar to that of the Pixel 4 and Pixel 4 XL's but solely relying on the phone's front camera rather than on Project Soli radar technology; the feature was canceled for unknown reasons shortly prior to the launch event.
Software
As with prior generations of the Pixel phone, Google placed heavy emphasis on artificial intelligence and ambient computing capabilities during the Pixel Fall Launch event, debuting features such as Magic Eraser, Face Unblur, Motion Mode, Real Tone, Direct My Call, Wait Times, and Live Translate. Additionally, Assistant voice typing and grammar correction serve as exclusive features on the Pixel 6 series, while Google Pay's digital car key feature launched first on the Pixel 6, Pixel 6 Pro, and Samsung Galaxy S21 in November. Material You, a more personalized variant of Google's Material Design design language, was also a major focus in Google's marketing efforts.
The Pixel 6 and Pixel 6 Pro shipped with Android 12 at launch, coinciding with the stable release of Android 12 on the Android Open Source Project (AOSP), along with version 8.4 of the Google Camera app. It was originally set to receive three years of major OS upgrades and five years of security updates, but the former was later increased to five years, with support extending to 2026. Continuing the Pixel 5a's trend, the Pixel 6 and Pixel 6 Pro did not come with unlimited photo storage in "high quality" on Google Photos, being the second Pixel phone not to include the offer. Concurrently with the Pixel Fall Launch event, Android 12 became available on older Pixel phones, while the Security Hub and Privacy Dashboard were introduced. Google also announced Pixel Pass, a subscription bundle similar to Apple One and Xbox All Access which bundles the Pixel 6 series with Google One, YouTube Premium, YouTube Music Premium, Google Play Pass, and an extended warranty; the service was discontinued two years later, ahead of the launch of the .
Marketing
Google kickstarted the phones' marketing campaign early, beginning with online commercials, billboards in major cities, and magazine advertisements in September 2021. Pixel 6-themed potato chips were made available in Japan. Additionally, the company partnered with Channel 4, the NBA, and Snapchat to promote the phones. Models of the phones were also available on display at the Google Store Chelsea in New York City prior to the launch event. Google CFO Ruth Porat had previously revealed during parent company Alphabet's quarterly earnings investor call in August that the company was planning to substantially increase its marketing and sales expenses in anticipation for the phones' launch, while Google hardware chief Rick Osterloh declared their intention to "invest in marketing".
In November 2021, it was announced that actor Simu Liu, who portrays Shang-Chi in the Marvel Cinematic Universe (MCU) media franchise, would serve as the Pixel 6's brand ambassador in Canada, days after Liu shot a video as part of Google TV's "Watch with Me" marketing campaign. NBA athletes Giannis Antetokounmpo and Magic Johnson also serve as brand ambassadors for the phones in the U.S., with tennis player Leylah Fernandez doing the same in Canada. In February 2022, Google released a commercial titled "Seen on Pixel" which advertised the Pixel 6's Real Tone feature, ahead of its airing during Super Bowl LVI. It featured a then-unreleased song by Lizzo entitled "If You Love Me". Directed by Joshua Kissi and created in collaboration with advertising agency Gut Miami, the 60-second advertisement marked the company's first Pixel-related Super Bowl spot, and was noted by GLAAD as the only Super Bowl LVI commercial featuring LGBTQ people. Other promotions include Pixel 6 socks and a Tensor sticker for "Pixel Superfans", as well as a Pixel 6-themed tarot deck for #TeamPixel members ahead of Christmas in 2021.
Reception
Critical response
The Pixel 6 and Pixel 6 Pro received much attention prior to its launch. Ben Schoon of 9to5Google highlighted the potential of the new Tensor chip, finding Google's premature reveal of the devices to be a "show of confidence" in the Pixel 6 series. Michael L. Hicks of Android Central believed that the Pixel 6 and Pixel 6 Pro could appeal to iPhone users, urging Google to rethink its marketing strategy, while Sareena Dayaram of CNET opined that the phones were "more exciting" than Apple's iPhone 13. Commentators also noted the increased anticipation of the Pixel 6 series in comparison to earlier generations of the Pixel smartphone line, attributing this to its early reveal as well as the announcement of the Tensor chip.
Both phones received generally positive reviews following their release. Julian Chokkattu of Wired and Dan Seifert of The Verge praised their performance, cameras, and battery life, but criticized the speed of the fingerprint scanner and the large sizes of both models. On the contrary, Patrick Holland and Andrew Laxon of CNET took issue with the phones' battery life, though they both praised the phones' camera and design. Lanxon also highlighted the premium specifications of the Pixel 6 Pro, including the triple-camera setup, and believed it to be on par with the iPhone 13 and Samsung's Galaxy S21. Similarly, Jacon Krol of CNN Underscored and Sam Rutherford of Gizmodo appreciated the phones' design and cameras, with Krol declaring them "the best Android phones you can buy", though Rutherford also noted the slow fingerprint sensor and lack of a headphone jack. Philip Michaels and Jordan Palmer of Tom's Guide praised the phones' affordable pricing, the Tensor chip, and the debut of Android 12, but criticized the fingerprint scanner and battery life. Writing for TechRadar, David Lumb and James Peckham commended the phones' design, build, and cameras but found the battery life and storage subpar. Marques Brownlee praised the phones' competitive pricing, selfie cameras, and software features, but also noted the slow fingerprint sensor and poor battery life.
Commercial reception
Google accommodated the increased interest for the Pixel 6 and Pixel 6 Pro by signing partnership agreements with more than 45 wireless carriers and retailers across nine countries. Shortly after the phones became available for pre-order, both the online Google Store and the Google Fi store suffered temporary outages. Google attributed delayed shipping times for the Pro model to unexpectedly high demand on the Google Store, with other carriers also facing shipping delays.
In December 2021, a report indicated that the Pixel 6 and Pixel 6 Pro experienced greater carrier sales numbers during its first month of availability in comparison to prior models, while smartphone accessory manufacturer Bellroy announced that its phone cases for the Pixel 6 series were its most popular products of all time. During Alphabet's quarterly earnings investor call in February 2022, Google and Alphabet CEO Sundar Pichai touted "record" sales numbers for the company's 2021 Pixel phones, especially the Pixel 6 series; however, a later study conducted by Counterpoint Research revealed that the Pixel line may have only experienced moderate year-over-year growth in comparison to the Pixel 5. In March, the International Data Corporation (IDC) analyzed that the introduction of the Tensor chip on the Pixel 6 series had been a factor in allowing MediaTek to overtake Qualcomm as the most popular Android chip manufacturer in the U.S., though the latter disputed the report. Another report published by Counterpoint Research the same month revealed that Tensor made up approximately one to two percent of the high-end system-on-chip market.
In April 2022, a report from market research firm Wave7 claimed that the Pixel 6 and Pixel 6 Pro had experienced low carrier sales, with Google offering unusually high "kickbacks to salespeople" and Verizon finding the most success with the phones. Pichai stated that the Pixel 6 series were the fastest-selling Pixel devices ever, with the company further revealing during the 2022 Google I/O keynote on May 11 that the Pixel 6 and Pixel 6 Pro had been sold more than the Pixel 4 and Pixel 5 combined. Data from the IDC in October 2022 revealed that Google had sold approximately 3.75 million units of the Pixel 6 series globally by then. The Pixel 6 series was instrumental in allowing Google's smartphone market share in North America to increase by 380 percent during the first quarter of 2022, becoming the fifth-largest smartphone manufacturer in both North America and the United Kingdom for the first time; the next quarter, Pixel sales increased by 230 percent in North America, acquiring 2 percent of the smartphone market on the continent.
Future
The Pixel 6 and Pixel 6 Pro were succeeded by the Pixel 7 and Pixel 7 Pro in October 2022, with the phones first previewed during the 2022 I/O keynote. They were powered by the second-generation Tensor chip and shipped with Android 13. At I/O, Google also announced the Pixel 6a, a mid-range variant of the Pixel 6 series, which launched in July.
References
External links
Pixel 6 (archived)
Pixel 6 Pro (archived)
Pixel Fall Launch (archived)
Android (operating system) devices
Discontinued flagship smartphones
Foxconn
Google hardware
Google Pixel
Mobile phones introduced in 2021
Mobile phones with 4K video recording
Mobile phones with multiple rear cameras | Pixel 6 | [
"Technology"
] | 2,946 | [
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
68,388,930 | https://en.wikipedia.org/wiki/GV%20Tauri | GK Tauri is a young binary system composed of T Tauri-type pre-main sequence stars in the constellation of Taurus about away, belonging to the Taurus Molecular Cloud.
System
The stars GV Tauri A (GV Tauri S) and G Tauri B (GV Tauri N) form a wide binary system, with the projected separation between components being 170 AU. Both are strongly shrouded by circumstellar dust - GV Tauri A by 30 magnitudes and the GV Tauri B up to 59 magnitudes in the V band. Both components are suspected to be binaries themselves, as they produce strongly ionized jets and molecular outflows.
Properties
Both members of the binary system are medium-mass objects still contracting towards the main sequence and accreting mass, although accretion rates remain highly uncertain as of 2009.
Protoplanetary system
Both stars are surrounded by protoplanetary disks, with the observable dust in each being about , and the gas about 0.005 . The disk of GV Tauri B is rich in carbon monoxide, hydrogen cyanide and, unusually, methane.
References
Binary stars
T Tauri stars
Circumstellar disks
Taurus (constellation)
J04292373+2433002
Tauri, GV | GV Tauri | [
"Astronomy"
] | 276 | [
"Taurus (constellation)",
"Constellations"
] |
68,389,279 | https://en.wikipedia.org/wiki/HD%203443 | HD 3443 is a binary system composed of medium-mass main sequence stars in the constellation of Cetus about away.
System
This binary star system, with an orbital semimajor axis 8.9 AU, has not had any circumstellar dust detected as of 2020. While the habitable zones of the stars stretch from 0.55 to 0.95 AU from the stars, planetary orbits with a semimajor axis beyond 1.87 AU would become unstable due to the influence of the binary companion.
Properties
The star system is enriched in oxygen compared to the Solar System, having 140% of solar oxygen abundance, but is depleted in heavier elements, having 75% of solar abundance of iron.
References
Binary stars
Cetus
J00372057-2446023
CD-25 225
002941
0025
0159
G-type main-sequence stars
K-type main-sequence stars
003443 | HD 3443 | [
"Astronomy"
] | 188 | [
"Cetus",
"Constellations"
] |
68,390,653 | https://en.wikipedia.org/wiki/Happy%20victimizing | Happy victimizing phenomenon, happy victimization phenomenon or happy victimizer phenomenon is a phenomenon in child development, particularly moral development and cognitive development. It amounts to an apparent disparity in moral conceptions of children under the age 6-7: while they understand that acts of victimization are wrong, they attribute exclusively positively valenced or "happy" emotions to victimizers, who achieve their goals while harming others. While the belief that "getting what one wants" is good regardless the cost may be attributed to people of any age, the happy victimizer phenomenon appears to contradict a number of mainstream theories according to which the awareness of victims' harm is supposed to give rise to certain negative emotions, such as remorse or fear of punishment.
Bryan Sokol points out that the earliest demonstration in which young children ascribed wrongdoers positive emotions was provided in 1980 by Barden, Zelko, Duncan, and Masters. In their test, they provided 40 hypothetical situations and asked subjects to predict one of the selected affective reactions ("happy", "scared", "sad", etc.) They singled out an observation that the situation "dishonesty (not caught)" was predicted by the youngest children to produce the "happy" emotion, while in the oldest group the consensus was for "fear". A more detailed report, frequently cited as pioneering, was that of Nunner-Winkler and Sodian (1988). In an effort to clarify the nature of young children's morality, they conducted a certain experiment and reported that most 4-year-olds attributed positive moral emotions to the wrongdoer focusing on the successful outcome of the wrongdoer's action, while 8-year-olds focused on the moral value of the wrongdoer's action and therefore attributed him negative feelings.
References
Further reading
Gerhard Minnameier, "The problem of moral motivation and the happy victimizer phenomenon: killing two birds with one stone", New Dir Child Adolesc Dev. Fall 2010;2010(129):55-7,
Gertrud Nunner-Winkler, "Moral Motivation and the Happy Victimizer Phenomenon", In: Handbook of Moral Motivation. Moral Development and Citizenship Education, vol 1. SensePublishers, Rotterdam.
Arsenio, W., & A. Lover (1995). Children’s conceptions of sociomoral affect: Happy victimizers, mixed emotions, and other expectancies. In M. Killen and D. Hart (Eds.), Morality in everyday life (pp. 87-128). New York: Cambridge University Press.
Keller, M., O. Lourenco, et al. (2003). The multifaceted phenomenon of ’happy victimizers’: A crosscultural comparison of moral emotions. British Journal of Developmental Psychology, 21, 1-18.
Lourenco, O. (1997). Children’s attributions of moral emotions to victimizers: Some data, doubts and suggestions. British Journal of Developmental Psychology, 15, 425-438.
Gerhard Minnameier, A cognitive approach to the ‘happy victimiser’, Journal of Moral Education, , 41, 4, (491-508), (2012).
Child development
Developmental psychology
Moral psychology
Abuse
Harassment and bullying
Victimology | Happy victimizing | [
"Biology"
] | 682 | [
"Behavior",
"Developmental psychology",
"Abuse",
"Behavioural sciences",
"Harassment and bullying",
"Aggression",
"Human behavior"
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68,391,510 | https://en.wikipedia.org/wiki/Balloon%20popping | A balloon pops when the material that makes up its surface tears or shreds, creating a hole. Normally, there is a balance of the balloon skin's elastic tension in which every point on the balloon's surface is being pulled by the material surrounding it. However, if a hole is made on the balloon's surface, the force becomes imbalanced, since there is no longer any force exerted by the center of the hole on the material at its edge. As a result, the balloon's surface at the edge of the hole pulls away, making it bigger; the high pressure air can then escape through the hole and the balloon pops. A balloon can be popped by either physical or chemical actions. Limpanuparb et al. use popping a balloon as a demonstration to teach about physical and chemical hazards in laboratory safety.
Physical
A pin or needle is frequently used to pop a balloon. As the needle or pin creates a hole on the balloon surface, the balloon pops. However, if tape is placed on the part where the hole is created, the balloon will not pop since the tape helps reinforce the elastic tension in that area, preventing the edges of the hole pulling away from the center. Likewise, the thick spots of the balloon at the top and the bottom can be pierced by a needle, pin, or even skewer without the balloon popping.
Chemical
Organic solvent
Applying an organic solvent such as toluene onto a balloon's surface can pop it, since the solvent can partially dissolve the material making up the balloon's surface.
cis-1,4-polyisoprene (solid) + organic solvent → cis-1,4-polyisoprene (partly dissolved)
Baby oil can also be applied to water balloons to pop them.
Orange peel
Orange peel contains a compound called limonene which is a hydrocarbon compound similar to the rubber that can be used to make balloons. Based on "like dissolves like" principle, rubber balloons can be dissolved by limonene, popping the balloon. If the balloon is vulcanized (hardened with sulfur), the balloon will not pop.
Gallery
See also
Balloon phobia
References
Balloons
Physics education
Chemistry classroom experiments
Articles containing video clips
External links
The science behind why a balloon pops when squirted with an orange peel. | Balloon popping | [
"Physics",
"Chemistry"
] | 469 | [
"Applied and interdisciplinary physics",
"Physics education",
"Balloons",
"Chemistry classroom experiments",
"Fluid dynamics"
] |
68,392,179 | https://en.wikipedia.org/wiki/Carbon%20storage%20in%20the%20North%20Sea | Carbon storage in the North Sea (also known as carbon sequestration in the North Sea) includes programmes being run by several Northern European countries to capture carbon (in the form of carbon dioxide, ), and store it under the North Sea in either old oil and gas workings, or within saline aquifers. Whilst there have been some moves to international co-operation, most of the Carbon Capture and Storage (CCS) programmes are governed by the laws of the country that is running them. Because the governments have pledged net zero carbon emissions by 2050, they have to find ways to deal with any remaining produced, such as by heavy industry. Around 90% of the identified storage geologies for carbon dioxide in Europe are shared between Norway and the United Kingdom; all of the designated sites for storage are located in the North Sea.
The first carbon storage operation to utilise the North Sea bed, was the Sleipner Field in 1996, which was operated by a Norwegian oil and gas company. However, the storage of carbon was down to the gas product having a high carbon content, and so needed to be scrubbed (stripped) of its carbon, which was pumped back down into the gas well.
Background
Gas and oil were first discovered in the North Sea off the coast of The Netherlands in 1959. This led to a huge oil and gas industry, and whilst the industry peaked around the year 2000, it is projected that gas and oil could be successfully recovered from the North Sea until the 2050s. A 1958 law enacted by the United Nations (United Nations Convention on the Continental Shelf), and a later law from 1982 (United Nations Convention on the Law of the Sea [UNCLOS]), afforded nations certain rights for the use of the seabed on the continental shelf, but also, the responsibilities that a country should adhere to. So, whilst installing oil and gas rigs was allowed, the rigs and pipelines are sometimes required to be removed when the drilling was finished to avoid interfering with shipping and fishing. This is of paramount importance off the coast of The Netherlands where the coastal waters are very shallow, but for Norway and the UK, decisions could be taken on a case-by-case basis, thereby affording the opportunity of re-using the infrastructure for CO2 storage.
The previous use of drilling for oil and gas, and the plentiful availability of the saline aquifers on the sea bed, means that Norway and the United Kingdom share 90% of the identified locations that are geologically stable enough to store carbon dioxide under pressure. The chief executive of Storegga, a company behind a scheme to store carbon working from Scotland stated that "..While I don’t doubt there will be other stores found in Europe over time . . . they will still be dwarfed by the North Sea."
Although carbon storage is deemed by most scientists as an essential element to the reduction of greenhouse gas emissions, the cost of removal of the CO2, the transportation and then the eventual storage of the gas, is quite prohibitive, and as countries have pledged a net zero economy by 2050, efforts have been concentrated on the technologies to deal either with the carbon produced, or to remove it entirely. In April 2021, the commercial removal, transportation and storage of CO2 was rated at $600 per tonne, but this was expected to be reduced to between $200 and $300 by the late 2020s. Despite the necessity to achieve carbon-zero programmes, there has been public opposition to storing carbon onshore, and the North Sea offers the largest offshore storage capacity in Europe.
Whilst studies have developed the prospect of storing in the depths of the sea, where the pressure will keep it submerged, the preferred method is for storage in old oil and gas wells. When CO2 mixes with seawater, the imbalance may harm marine life, and would lead to a "measurable change in ocean chemistry".
The first commercial storage of in the North Sea (and in the world) was enacted in 1996 at the Sleipner gas field, though the carbon was removed from the gas on-site (ie, at sea) and pumped into a saline aquifer due to commercial reasons. However, the monitoring of the storage site, and the data acquired over the years provides a useful benchmark for other projects to learn from. A study conducted on the Sleipner storage reservoir in 2003, when it had been in operation for seven years, determined that the CO2 would not "migrate into the North Sea for 100,000 years. Others have stated that whilst seepage from storage reservoirs may be inevitable, the loss rate will be negligible and the environmental impact of not storing CO2 would be worse. Similarly, a study conducted in the Forties Oil Field, determined that over a 1,000 year period, 0,2% of the CO2 would leach out of the storage facility and move upwards. Even so, the maximum distance it would move would be only half the distance to the seabed level. However, some existing oil and gas wells were leaking methane into the sea. A study in 2012/2013, determined that of 43 wells observed in the North Sea, 28 were leaching methane, the second most important greenhouse gas after carbon dioxide. Methane in the sea water leads to acidification of the water.
The ability to re-use depleted oil and gas wells, or saline aquifers, and the ability to back flow carbon dioxide through redundant pipelines, means a cost-saving benefit. A study conducted by University of Edinburgh on the Beatrice Oilfield off the coast of Scotland, determined that decommissioning the oil platform would cost £260 million, but re-purposing the platform to accept captured over a thirty-year period, would cost only £26 million. One scheme slated to be worked from the St Fergus Gas Terminal in Scotland, would save £730 million by pumping the CO2 back through the redundant pipelines, saving on investment in transportation. Some of the UK schemes are looking beyond their domestic markets in terms of CO2 storage, and will lobby to store the gas on behalf of other nations. One storage site investigated lies down, under the Moray Firth off the east coast of Scotland. The depleted reservoir lies underneath the Captain Sandstone Formation, and if was injected from two points simultaneously, the reservoir has the capacity to store in just 1/6 of its area. This is the amount of emitted by Scotland over 23 years.
In 2009, the European Union issued a directive governing carbon capture and storage, stating that sites for storage need to be secure against harm to human health, and that operators must have the financial backing to see the project through, should problems occur. Companies (and Member States) that store CO2 under the conditions of the directive, are free to designate the CO2 as not having been "emitted" under the Emission Trading Scheme.
Enhanced oil recovery
Enhanced oil recovery (EOR), involves injecting into oil fields to force remaining oil and residues out of the field. This can extend the life of the oilfield in addition to storing the , provided the geology is stable enough to do so. The technology for this has been proven onshore, but offshore workings are still under evaluation. Two projects in the North Sea were initiated in 1998 and in 2002, one which involved injected liquid methane into an oil well. The success of the two ventures led to increased confidence in the use of EOR offshore. A further venture at the Forties Oil Field has been suggested, which would store the and make the oil recovery easier, although not economically viable.
Denmark
Project Greensand
A consortium of three companies (Ineos, Maersk Drilling and Wintershall Dea) are running a project to store carbon in the Nini West oilfield. The susbsea reservoir was confirmed as feasible in November 2020 after a drilling programme determined that it could store of captured over a ten-year period. The Nini West subsea reservoir is estimated to be below the sea, and in an area which has been geologically stable enough to store oil and gas for 20 million years.
Norway
Gas and oil exploration, drilling, and recovery of assets used in those ventures are awarded by the Ministry of Petroleum and Energy (MPE). As the Continental Shelf in Norwegian waters consists of very deep water, pipelines can be left in-situ when they become redundant provided they do not interfere with fishing rights.
Sleipner Field
Drilling of the Sleipner Oil and Gas Field initiated a project in 1996 to remove the carbon dioxide from the gas it was acquiring from the gas field some below the sea level. It was rated with around 9% , which needed to be reduced significantly if the gas was to be commercially acceptable. A level of 2.5% was stipulated due to pipeline specifications and also to meet a carbon tax enacted by the Norwegian Government in 1990. The process involves passing the natural gas through an amine scrubber which removes the , and then the amine/ mix is heated up, producing a pure CO2 stream that is piped back down to the seabed and stored in a saline reservoir. This reservoir has been monitored since the project started in 1996 so that the cap rock keeps the gas contained. The cap rock is Nordland Shale, with a thickness varying between and .
By 2011, over of had been sequestered in the saline aquifer in the Utsira sand formation underneath the sandstone cap. The operation is carried out with adherence to Norwegian petroleum law.
Project Longship
In 2011, a project in Norway targeted at reducing carbon in power plants (coal and gas) failed to gain any ground. The project did not work because the energy source could be switched to renewables. In 2021, another proposal, Project Longship, unveiled a kr25 billion ($3 billion) plan to target the carbon emissions from cement, glass, paper and fertiliser plants, which emit large tonnages of carbon in their production processes.
By January 2021, the sides of a fjord outside Bergen had been cut out with explosives to site the tanks needed to store the captured . The consortium running Longship have stated that their aim is to run a business and expect to take shiploads of captured CO2 from as far afield as Northern Spain.
United Kingdom
Drilling for oil and gas in and around the United Kingdom is governed by the Petroleum Act 1998, but the storage of is directed by the Energy Act 2008. The UK oil and gas industry is not state owned, as it is in the Netherlands and Norway.
By 2030, the UK government wish to see four industrial clusters, which will trap, transport and store carbon to prevent emissions into the atmosphere. The five largest industrial areas that have been selected to work on this are Grangemouth in Scotland; Teesside, the Humber and Merseyside in England; and Port Talbot in Wales. In 2012, the government sponsored two projects to go forward with CCS; one at Peterhead/St Fergus in Scotland based on the combustion of natural gas, and the other at Drax Power Station in North Yorkshire in England.
Besides the North Sea, which is listed by stored in three different regions (Northern North Sea, Central North Sea, Southern North Sea), the coastal waters around the United Kingdom also have identified sites in the East Irish Sea, and the English Channel. Altogether, sites identified around the UK continental shelf have the capacity to store over 4 billion tonnes (including in the Irish Sea).
England
Heavy industry on Teesside and the Humber Estuary, (known as the East Coast Cluster), have combined to focus storing in a saline aquifer under the North Sea, under the name Northern Endurance Partnership. The combined carbon output from the two industrial areas, account for almost 50% of that which is emitted by heavy industry in the United Kingdom. The Endurance storage site, which is offshore of the Yorkshire Coast, and below the seabed, was initially earmarked for a carbon capture project (the White Rose) from Drax power station, that was cancelled in 2015.
Net Zero Teesside (NZT)
A proposal to site a power station on the site of the former Redcar Steelworks was announced in 2021. The Whitetail Energy Plant is expected to be operational by 2025. Both NZT and ZCH, aim to be operating fully by 2026, and would look to use the Endurance Aquifer for carbon storage. The original proposal for the White Rose Project, estimated that the storage capacity of the Endurance Aquifer was .
Zero Carbon Humber
Zero Carbon Humber (ZCH) is the Zero Carbon programme for Humberside, the region which straddles the north and south banks of the Humber Estuary on the East Coast of England. The region is the largest emitter of processed carbon in the United Kingdom, releasing annually. H2H Saltend is a proposed low carbon hydrogen plant that will aim to be producing hydrogen from natural gas by 2027. The cancelled White Rose Project, planned for a pipeline to travel to the aquifer from the Humber area and make leave the coastline at Barmston.
Scotland
Acorn CCS intends to focus its efforts on heavy industry around Grangemouth, with the gas terminal at St Fergus being the export point through the Goldeneye Pipeline to the redundant Goldeneye field, north-east of Aberdeen, and below sea level. The Goldeneye platform exported gas between 2004 and 2011, with permission to decommission the platform in 2019, however, plans were submitted to keep the options open for the rig in case of a CCS programme. The pipeline connecting St Fergus to the Goldeneye field is a carbon-steel tube which is in diameter. The depleted gas well lies at , underneath layers of sandstone, shale and chalk. However, funding for the project from the UK government was cancelled in 2015.
A direct air capture project aims to install a plant that sucks air through a giant fan and fixes the carbon in the air to a solution, which can be refined to enable the captured carbon to be stored. The positioning of such a plant in Scotland is thought to be favoured because the engineering involved is akin to the skills needed in the oil and gas industry, and the plant can be sited near to where the gas pipelines come ashore in Scotland.
Wales
The North Wales cluster will operate jointly with that of the North-West of England. Ahead of the COP 26 summit in Glasgow in 2021, the UK Government announced an investment of at least £140 million, to promote carbon carbon and hydrogen schemes in the North-West England/North Wales cluster, shared jointly with the Humber/Teesside venture. Carbon captured in Wales is planned to be sequestrated in old oil and gas wells in the Irish Sea, or transported to one of the North Sea projects for storage.
Other countries
The Netherlands, Germany, France and Sweden all recognise the need for carbon capture programmes. In 2021, many of these were considering storage under the North Sea. However, none have stated whether they will progress their own storage, or pay for the disposal of the carbon at either the Danish, Norwegian or British sites.
See also
North Sea oil
White Rose Project
Whitetail Clean Energy
Notes
References
Sources
External links
CCS Norway
CO2 stored website
Project Greensand
Zero Carbon Humber
CO2 storage and Enhanced Oil Recovery in the North Sea
A Carbon Capture, Utilisation, & Storage Network for Wales
Carbon capture and storage
Emissions reduction | Carbon storage in the North Sea | [
"Chemistry",
"Engineering"
] | 3,142 | [
"Greenhouse gases",
"Geoengineering",
"Carbon capture and storage",
"Emissions reduction"
] |
72,749,034 | https://en.wikipedia.org/wiki/EA-3887 | EA-3887 is a carbamate nerve agent. The iodide salt of EA-3887 is EA-3887A.
See also
3152 CT
EA-3966
EA-3990
EA-4056
T-1123
TL-1238
References
Carbamate nerve agents
Pyridines
Quaternary ammonium compounds
Acetylcholinesterase inhibitors
Bromides
Bisquaternary anticholinesterases
Aromatic carbamates | EA-3887 | [
"Chemistry"
] | 99 | [
"Bromides",
"Salts"
] |
72,749,652 | https://en.wikipedia.org/wiki/V380%20Cygni | V380 Cygni is an eclipsing binary star in the constellation Cygnus, located about 3,800 light years away from the Earth. Its apparent magnitude ranges from 5.61 to 5.78, making it faintly visible to the naked eye of an observer located far from city lights. Because it is an important test object for models of massive stars, it has been the subject of many scientific studies.
V380 Cygni was discovered to be a spectroscopic binary by Walter Sydney Adams, based on three spectra taken on separate nights in 1912 at the Mount Wilson Observatory. The binary's orbit was first calculated from spectra obtained in 1920 at the DDO; the period was found to be 12.427 days. Because the physical separation of spectroscopic binaries is often relatively small, they are good candidates to be eclipsing binaries. For that reason, in 1923 Joel Stebbins included V380 Cygni (then called Boss 5070) in an early photo-electric photometry study. A secondary eclipse was detected in June 1923 on the first night the star was observed.
V380 Cygni was observed several times at high cadence, for many days, by the Kepler space telescope. In addition to the brightness variations caused by eclipses, the Kepler data showed that the primary star has significant intrinsic variability which is most apt to be caused by gravity-mode oscillations.
References
Algol variables
Cygnus (constellation)
97634
187879
Durchmusterung objects
Cygni, V380
7567 | V380 Cygni | [
"Astronomy"
] | 321 | [
"Cygnus (constellation)",
"Constellations"
] |
72,749,655 | https://en.wikipedia.org/wiki/Diaporthomycetidae | Diaporthomycetidae is a subclass of sac fungi under the class Sordariomycetes.
The subclass was formed in 2015 for some fungi taxa that were already placed within Sordariomycetidae subclass but that were phylogenetically and morphologically distinct from genera in Sordariomycetidae. Members of Diaporthomycetidae can occur in both aquatic and terrestrial habitats as saprobes (living on decayed dead or waste organic matter), pathogens, or endophytes (within a plant for at least part of its life cycle without causing apparent disease).
In 2017, there were up to 15 orders and 65 families in this subclass. More orders may be confirmed in DNA-based phylogenetic analysis studies in 2021.
Distribution
Member in the order have a cosmopolitan distribution, including being found in China and Thailand, and parts of Europe.
They can be found in freshwater habitats.
Orders
As accepted by Wijayawardene et al. 2020;
Annulatascales - family Annulatascaceae (with 13 genera)
Atractosporales
Atractosporaceae (2)
Conlariaceae (2)
Pseudoproboscisporaceae (3)
Calosphaeriales
Calosphaeriaceae (4)
Pleurostomataceae (1)
Diaporthales
Apiosporopsidaceae (1)
Apoharknessiaceae (2)
Asterosporiaceae (1)
Auratiopycnidiellaceae (1)
Coryneaceae (2)
Cryphonectriaceae (27)
Cytosporaceae (6)
Diaporthaceae (15)
Diaporthosporellaceae (1)
Diaporthostomataceae (1)
Dwiroopaceae (1)
Erythrogloeaceae (4)
Foliocryphiaceae (2)
Gnomoniaceae (37)
Harknessiaceae (2)
Juglanconidaceae (2)
Lamproconiaceae (2)
Macrohilaceae (1)
Mastigosporellaceae (1)
Melanconidaceae (1)
Melanconiellaceae (8)
Neomelanconiellaceae (1)
Phaeoappendicosporaceae (2)
Prosopidicolaceae (1)
Pseudomelanconidaceae (3)
Pseudoplagiostomataceae (1)
Pyrisporaceae (1)
Schizoparmaceae (1)
Stilbosporaceae (4)
Sydowiellaceae (21)
Synnemasporellaceae (1)
Tubakiaceae (8)
Distoseptisporales - Distoseptisporaceae (1)
Jobellisiales - Jobellisiaceae (1)
Magnaporthales
Ceratosphaeriaceae (1)
Magnaporthaceae (24)
Ophioceraceae (2)
Pseudohalonectriaceae (1)
Pyriculariaceae (11)
Myrmecridiales
Myrmecridiaceae (2)
Xenodactylariaceae (1)
Ophiostomatales
Kathistaceae (3)
Ophiostomataceae (12)
Pararamichloridiales - Pararamichloridiaceae (1, Pararamichloridium)
Phomatosporales - Phomatosporaceae (3)
Sporidesmiales - Sporidesmiaceae (1, Sporidesmium)
Tirisporellales - Tirisporellaceae (3)
Togniniales - Togniniaceae (1)
Xenospadicoidales - Xenospadicoidaceae (5)
Incertae sedis
As accepted by Wijayawardene et al. 2020;
Families
Barbatosphaeriaceae
Barbatosphaeria (9)
Ceratostomella (18)
Xylomelasma (4)
Papulosaceae
Brunneosporella (1)
Fluminicola (5)
Papulosa (1)
Wongia (3)
Rhamphoriaceae
Rhamphoria (15)
Rhamphoriopsis (1)
Rhodoveronaea (1)
Xylolentia (1)
Thyridiaceae
Pleurocytospora (3)
Thyridium (34)
Trichosphaeriaceae
Aquidictyomyces (1)*
Brachysporium (25)
Collematospora (1)
Coniobrevicolla (1)
Eriosphaeria (24)
Koorchaloma Subram. (11)
Rizalia (6)
Schweinitziella (4)
Setocampanula (1)
Trichosphaeria (20)
Unisetosphaeria (1)
Woswasiaceae
Cyanoannulus (1)
Woswasia (1)
Xylochrysis (1)
Genera incertae sedis
Aquimonospora (1)
Aquaticola (5)
Fusoidispora (1)
Kaarikia (1)*
Platytrachelon (1)
Proliferophorum (1)
Pseudoconlarium (1)
Pseudostanjehughesia (1)
References
Sordariomycetes
Fungus subclasses
Fungus taxa
Taxa described in 2015 | Diaporthomycetidae | [
"Biology"
] | 1,099 | [
"Fungus taxa",
"Fungi"
] |
72,750,596 | https://en.wikipedia.org/wiki/E%20Bija%20e%20H%C3%ABn%C3%ABs%20dhe%20e%20Diellit | E Bija e Hënës dhe e Diellit ("the Daughter of the Moon and the Sun") is a character in Albanian mythology and folklore, the daughter of Hëna ("the Moon") and Dielli ("the Sun"). She is the as ("drop of the sky" or "lightning") which falls everywhere from heaven on the mountains and the valleys and strikes pride and evil. In the legends she helps a hero winning a fight against a kulshedra. Her victory over the kulshedra symbolizes the supremacy of the deity of the sky over that of the underworld in the dualistic struggle between light and darkness.
Mythology
In Albanian folk beliefs the sun (Dielli) and the moon (Hëna) are personified deities. In folk tales, myths and legends the sun appears as a male figure, and the moon as a female figure. In some traditions the sun and the moon are regarded as husband and wife, and in other traditions as brother and sister. In the case of E Bija e Hënës dhe e Diellit the sun is her father and the moon is her mother.
E Bija e Hënës dhe e Diellit is described as ("drop of the sky" or "lightning") which falls everywhere from heaven on the mountains and the valleys and strikes pride and evil. In the legends she helps a hero in his fight against a kulshedra, an earthly/chthonic deity or demon originating from darkness. In Albanian mythology the kulshedra is usually fought and defeated by the drangue, also seen as a sky and lightning deity or divine hero. The supremacy of E Bija e Hënës dhe e Diellit and of other similar celestial Albanian characters – such as Zjermi who is born with the Sun on his forehead – over the kulshedra, reflects the supremacy of the deity of the sky over that of the underworld in the dualistic struggle between light and darkness.
In literature
The legend of E Bija e Hënës dhe e Diellit has also been narrated by the Albanian writer Mitrush Kuteli in the collection Tregime të moçme shqiptare ("Old Albanian tales"), published in 1965.
References
Citations
Bibliography
Albanian paganism
Albanian mythology
Albanian legendary creatures
Sky and weather deities | E Bija e Hënës dhe e Diellit | [
"Physics"
] | 483 | [
"Weather",
"Sky and weather deities",
"Physical phenomena"
] |
72,750,759 | https://en.wikipedia.org/wiki/Sparrow%20%28chatbot%29 | Sparrow is a chatbot developed by the artificial intelligence research lab DeepMind, a subsidiary of Alphabet Inc. It is designed to answer users' questions correctly, while reducing the risk of unsafe and inappropriate answers. One motivation behind Sparrow is to address the problem of language models producing incorrect, biased or potentially harmful outputs. Sparrow is trained using human judgements, in order to be more “Helpful, Correct and Harmless” compared to baseline pre-trained language models. The development of Sparrow involved asking paid study participants to interact with Sparrow, and collecting their preferences to train a model of how useful an answer is.
To improve accuracy and help avoid the problem of hallucinating incorrect answers, Sparrow has the ability to search the Internet using Google Search in order to find and cite evidence for any factual claims it makes.
To make the model safer, its behaviour is constrained by a set of rules, for example "don't make threatening statements" and "don't make hateful or insulting comments", as well as rules about possibly harmful advice, and not claiming to be a person. During development study participants were asked to converse with the system and try to trick it into breaking these rules. A 'rule model' was trained on judgements from these participants, which was used for further training.
Sparrow was introduced in a paper in September 2022, titled "Improving alignment of dialogue agents via targeted human judgements"; however, the bot was not released publicly. DeepMind CEO Demis Hassabis said DeepMind is considering releasing Sparrow for a "private beta" some time in 2023.
Training
Sparrow is a deep neural network based on the transformer machine learning model architecture. It is fine-tuned from DeepMind's Chinchilla AI pre-trained large language model (LLM), which has 70 Billion parameters.
Sparrow is trained using reinforcement learning from human feedback (RLHF), although some supervised fine-tuning techniques are also used. The RLHF training utilizes two reward models to capture human judgements: a “preference model” that predicts what a human study participant would prefer and a “rule model” that predicts if the model has broken one of the rules.
Limitations
Sparrow's training data corpus is mainly in English, meaning it performs worse in other languages.
When adversarially probed by study participants it breaks the rules 8% of the time; however, this is still three times lower than the baseline prompted pre-trained model (Chinchilla).
See also
AI safety
Commonsense reasoning
Ethics of artificial intelligence
Natural language processing
Prompt engineering
References
External links
White paper
Blog post
Chatbots
Language modeling
Natural language processing
Large language models
Google DeepMind | Sparrow (chatbot) | [
"Technology"
] | 544 | [
"Natural language processing",
"Natural language and computing"
] |
72,752,078 | https://en.wikipedia.org/wiki/Scutigerella%20hauserae | Scutigerella hauserae is a species of symphylan myriapod found in Slovenia. It was described by Ulf Scheller, a Swedish entemologist, in 1990. It is known from Postojnska Jama, a cave system in Slovenia. It has several physical adaptations which may make it more suited for trogloniontic (cave) life.
Notes
References
Biota of Slovenia
Symphyla
Myriapods of Europe | Scutigerella hauserae | [
"Biology"
] | 97 | [
"Biota by country",
"Biota of Slovenia"
] |
72,753,814 | https://en.wikipedia.org/wiki/Phillip%20Geissler | Phillip L. Geissler (March 27, 1974 – July 17, 2022) was a theoretical chemist and the Aldo De Benedictis Distinguished Professor of Chemistry at UC Berkeley.
Geissler contributed to the theory and understanding of water, which he described as "a famously unusual liquid”. He was particularly interested in collective fluctuations that dictated kinetics in aqueous solutions, solvation, and ion-specific effects. He examined the vibrational spectra of water and the dynamical trajectories of water models and simulated air–water interfaces. He further studied the statistical mechanics of biological polymers and heterogeneous materials; explored pathways and guiding principles for nanoscale self-assembly; and developed techniques of model and algorithm development.
Education
Geissler was born in 1974 in Ithaca, New York. He grew up in Charlottesville and in Richmond, Virginia, graduating from Douglas S. Freeman High School.
Geissler attended Cornell University as an undergrad from 1992 to 1996. His senior thesis was titled A Theory for the Dynamics of Polymer Melts.
He received his masters' degree and PhD from UC Berkeley, graduating in 2000. He was a postdoc at UC Berkeley in 2000 and a postdoc under Eugene Shakhnovich at Harvard in 2001. He was also an MIT Science Fellow from 2001 to 2003.
Research and career
Geissler joined UC Berkeley as faculty in 2003, becoming a full professor in 2012.
Geissler's research interests included chemical phenomena in condensed phases, biomolecular structure and dynamics, fluctuations in nanomaterials, the elasticity of disordered networks of semiflexible polymers, and the dynamics of nanosolutes in a liquid undergoing phase transition.
Geissler established a program in non-equilibrium statistical mechanics. He gave the 2012 Baker Lecture, titled Why would a small ion adsorb to the air-water interface? and ran a colloqium titled When soft interfaces go still: fluctuating roughness as a driving force in nanoscale assembly.
Geissler was also affiliated with Lawrence Berkeley National Laboratory and the California Institute for Quantitative Biosciences.
Geissler was an editorial committee member for Annual Reviews of Physical Chemistry, Journal of Chemical Physics, Chemical Physics Letters, and Journal of Physical Chemistry.
Geissler received the UC Berkeley Distinguished Teaching Award in 2011.
Geissler was known for playing chemistry-themed songs on his guitar (such as "The Mole Song" or "Acids and Bases") when teaching class. He was also known for giving the same "quiz" on the first day of class.
Personal life
Geissler's hobbies and interests included California wine, guitar playing, hiking, watching soccer or baseball, science fiction, and woodworking.
On July 17, 2022, Geissler was hiking in Canyonlands National Park, attempting a hike from Elephant Hill, and went missing. His body was found on July 19.
References
External links
1974 births
2022 deaths
Theoretical chemists
UC Berkeley College of Chemistry faculty
Scientists from Ithaca, New York
Lawrence Berkeley National Laboratory people
Cornell University alumni | Phillip Geissler | [
"Chemistry"
] | 631 | [
"Theoretical chemists",
"American theoretical chemists"
] |
72,753,978 | https://en.wikipedia.org/wiki/LZ%20Cephei | LZ Cephei, also known by its Flamsteed designation 14 Cephei, is a star about 3,600 light years from the Earth, in the constellation Cepheus. Its apparent magnitude is 5.6, making it faintly visible to the naked eye of an observer far from city lights. The star is a rotating ellipsoidal variable whose brightness, as measured by the Hipparcos satellite, varies between magnitude 5.52 and 5.61.
LZ Cephei was discovered to be a binary star by William Edmund Harper in 1931.
The orbital elements were first calculated by Robert Methven Petrie in 1962. It was discovered to be a variable star in 1972 by N. Kameswara Rao, using the Lick Observatory's 24 inch telescope. The star was given the variable star designation LZ Cephei in 1973. It was classified as an ellipsoidal variable by Hill et al. in 1976.
A 2011 study of LZ Cephei concluded that the existing data are best explained if the system is a semi-detached binary with either the primary or secondary star nearly filling its Roche lobe. The secondary star, now less massive than the primary, was originally the more massive star, and matter has been transferred from the secondary to the primary.
References
Rotating ellipsoidal variables
Cepheus (constellation)
108772
209481
Durchmusterung objects
Cephei, LZ
Cephei, 14
8406 | LZ Cephei | [
"Astronomy"
] | 302 | [
"Constellations",
"Cepheus (constellation)"
] |
72,754,945 | https://en.wikipedia.org/wiki/Adrienne%20Porter%20Felt | Adrienne Porter Felt is an American computer scientist.
Education
Porter Felt completed her PhD at UC Berkeley in 2012. Her dissertation research focused on computer security on mobile devices. Her advisor was David Wagner. Her 2011 paper on Android permissions security won the ACM SIGSAC test-of-time award in 2022.
Career
After graduation, Porter Felt joined Google. Her work there focuses on computer security and Google Chrome. In 2014, she developed malware warnings in Chrome that are more intuitive for users. In 2016, she noted that the Google Chrome HTTPS lock icon looks more like a red purse than a lock. She conducted a study to design a more intuitive icon, and the new icon was deployed to users. In 2018, she worked on improvements to emoji in Google Chrome.
Personal life
Porter Felt's father, Edward Porter Felt was killed in the September 11 attacks.
References
External links
American computer scientists
Living people
Computer security specialists
Year of birth missing (living people)
Computer scientists
Google employees | Adrienne Porter Felt | [
"Technology"
] | 203 | [] |
72,755,145 | https://en.wikipedia.org/wiki/List%20of%20psychoactive%20substances%20derived%20from%20artificial%20fungi%20biotransformation | List of psychoactive substances derived from artificial fungi biotransformation.
4-HO-5-MeO-DMT (psilomethoxin) mushrooms derived from Psilocybe cubensis mycelium in substrate with added 5-MeO-DMT.
4-HO-DET and 4-PO-DET mushrooms derived from Psilocybe cubensis mycelium in substrate with added DET.
4-HO-DiPT mushrooms derived from Psilocybe cubensis mycelium in substrate with added DiPT.
4-HO-DPT mushrooms derived from Psilocybe cubensis mycelium in substrate with added DPT.
Baeocystin (4-PO-NMT) found in Psilocybe cubensis mushrooms from mycelium in substrate with added NMT.
See also
Biodiversity and drugs
List of psychoactive substances and precursor chemicals derived from genetically modified organisms
References
Drug-related lists
Biological sources of psychoactive drugs
Entheogens
Tryptamines
Psychedelic drugs | List of psychoactive substances derived from artificial fungi biotransformation | [
"Chemistry"
] | 209 | [
"Drug-related lists"
] |
72,756,571 | https://en.wikipedia.org/wiki/Suicidal%20ambivalence | Suicidal ambivalence is the coexistence of the will to live and the desire to die in people with suicidal tendencies.
As Craig Bryan et al. point out, one could suppose that people at high suicide risk would generally want to die. However, apart from the desire of death, they actually present the desire to continue living, which implies that they are ambivalent to the matter of life and death. Kovacs & Beck in 1977 described this idea as the internal struggle hypothesis. They corroborated it by research in which half of patients hospitalized after a suicide attempt admitted to having an internal struggle between life and death: 40% of them were inclined to death and 9% expressed a will to live. Moreover, subsequent research showed that ambivalence does not disappear even in the moment of a suicide attempt.
Suicidal ambivalence is a predictor of suicidal behaviors. Suicidal risk depends on the relative balance of the will of live and wanting to die. In one study of subjects ambivalent about suicide, persons inclined towards death were 6.5 times more likely to die than those and inclined towards living. O'Connor et al. even tried to categorize people at risk due to suicidal ambivalence. Patients with a prevailing desire to die were significantly more likely to attempt suicide than were ambivalent persons or those with a prevailing will to live. The group differed also in the level of helplessness and subjectively perceived suicide risk.
In the case of someone in crisis, a full psychiatric examination is recommended with possible psychiatric hospitalization depending on suicide risk evaluation.
References
Suicide | Suicidal ambivalence | [
"Biology"
] | 328 | [
"Behavior",
"Human behavior",
"Suicide"
] |
72,757,396 | https://en.wikipedia.org/wiki/Sphacelaria | Sphacelaria is a genus of brown macroalgae (or seaweed) in the family Sphacelariaceae.
Taxonomy and nomenclature
The genus and its type species (Sphacelaria reticulata) were briefly described by Hans Christian Lyngbye in Florae Danicae in 1818. At the time of publication, such brief descriptions were considered to be valid by virtue of descriptio generico-specifica; Lyngbye immediately added nine more species to the genus in 1819. Recent studies, however have revealed that this genus is polyphyletic, with the type species forming a separate clade with from the rest of the genus—in addition, it was also observed that S. reticulata does not exhibit the key morphological characteristics of the genus. Thus, it has been proposed to change the type species into S. cirrosa, one of the most widespread species, to conserve the genus name. Dr. Willem F. Prud’homme van Reine (1941–2020) was the foremost expert on Sphacelaria taxonomy and has contributed to the clarification and naming of the 37 confirmed species.
Morphology
Sphacelaria is mainly characterized by the blackening of their cell walls when treated with bleach, polystichous (parenchymatous) filamentous thallus, hemiblastic branching (i.e. laterals arise from the secondary), and leptocaulus growth (i.e. uniform size of filaments, such as their mature segments have almost the same diameter as their apical ones); moreover majority of the species also have specialized branchlets for vegetative reproduction called propagules. Delineation of Sphacelaria species have been traditionally based on morphological differences, especially the variation among the propagule shape, cell dimensions, and cell arrangement of the propagules. In terms of cellular ultrastructure, Sphacelaria cells contain discoid chloroplasts and do not have pyrenoids.
Distribution
Sphacelaria is a cosmopolitan genus with a majority of the species found in temperate regions but representatives also thrive in the tropics up to the arctic and antarctic areas. Species from this genus are mainly marine, however, freshwater species have been found in USA (S. lacustris) and China (S. fluviatilis).
Ecology
Sphacelaria species are epiphytic and/or epilithic in nature, they form filamentous tufts or mats on the surfaces they have reclaimed and are normally found on the intertidal to shallow subtidal.
Life history
Members of this genus exhibit isomorphic (i.e., the gametophyte (N) and sporophyte (2N) stage are morphologically similar) and diplohaplontic [i.e., both gametophyte (N) and sporophyte (2N) generations are free-living and equally distinct bodies but only differ in chromosome number and strategy] life cycle with isogamy (i.e., gametes with the same size and form) or anisogamy (i.e., gametes with different size and form). Culture studies have revealed that the reproductive strategy of Sphacelaria species are mainly dictated by the temperature, wherein propagule formation is favored during warmer seasons while sexual reproduction (i.e., formation of plurilocular and unilocular gametangia /zoidangia) occur when temperatures drop; in addition, daylength exposure is believed to contribute to the production of propagules and consequent inhibition of gametogenesis.
Exploitation, harvesting and cultivation
This genus is neither commercially nor traditionally cultivated and harvested.
Chemical composition and natural products chemistry
Sphacelaria has been known to contain several natural products such as carotene, chlorophyll a, and fucoxanthin (the pigment responsible for the brown color of phaeophycean seaweeds). Furthermore, they also contain sulfated polysaccharides in the form of xylogalactofucan and alginic acid which have shown to have antiviral properties against the herpes simplex virus type 1 (HSV-1).
Utilization and management
This genus has been used for plant morphogenesis studies, environmental stressors research, and much of the industry interest on Sphacelaria revolves around its easy protoplast production which has implications in cellular studies involving expression profiling, RNA sequencing, and transcriptomics.
References
Brown algae genera
Brown algae | Sphacelaria | [
"Biology"
] | 949 | [
"Algae",
"Brown algae"
] |
72,757,519 | https://en.wikipedia.org/wiki/Kakyen | Kakyen (), also known as Kakyen Mingamba () or Kakyel Meengamba (), was a big man-eating bird mentioned in Meitei mythology, folklore and history of Kangleipak (Manipur). According to legends, it used to serve King Kangba. It used to eat dead bodies thrown at the water bodies, especially a river near Heibok Ching. It was best known for having a fight with two Meitei princes, Taothingmang and Yoimongba. It was later killed by the two brothers.
According to the Sakok Lamlen Ahanba () text, Kakyen was mentioned as the king of the birds and was named as "Thilpai Ngamba Thinungkhak" ().
Kakyen was mentioned in the Tutenglon () text. The book was about the heroic works of the two Meitei princes, Yoimongba and Taothingmang.
Story
Once Kakyen started killing many people and destroying many villages, including Lokha Haokha area () in ancient Kangleipak. The people requested Taothingmang () and Yoimongba (), the two sons of Khuyoi Tompok (), the then King of Kangleipak, to kill the bird to save them. So, the two royal brothers worshipped goddess Leimarel (Leimalel). The goddess blessed the two men with a divine bow (along with a quiver full of arrows) and a divine sword.
Later, they met the bird. Yoimongba held the sword and Taothingmang held the bow and arrows (in the quiver). Kakyen swallowed prince Yoimongba. Taothingmang shot his arrows to the bird. The bird flew away. Inside its body, Yoimongba cut the bird using his sword. Later, the bird was killed. One of its wings was chopped off.
In another version of the story, goddess Leimarel suggested the brothers to worship goddess Panthoibi () to get the weapons. And the boys did so.
Nomenclature of places
One of the Kakyen bird's chopped off wings was used to stop the flow of water as a dam. That place was later known as "Ithing" (). The place where the bird was beheaded was called "Kaklou" ().
The place where Kakyen was killed was also known as "Kakyen Phabi" ().
Festival
The killing of the Kakyen was celebrated as a part of the festival of Mera Chaorel Houba (), including the Mera Hou Chongba () by the Meitei people and the tribal people of Kangleipak (present day Manipur). The body of the Kakyen was cut into pieces and cooked by the people. Both Meitei people and the tribal people of Kangleipak together had a big feast of the Kakyen meat. However, as there would be no more Kakyen, but they still wanted to celebrate the festival next year, they collectively decided to have feasts on cattle meat instead from the coming years. For the event, they annually sacrificed seven big cattle animals to the gods, and later ate the meat. The ceremony was known as "mera santuba" ().
In popular culture
The Tales of Kanglei Throne, an English language book by Linthoi Chanu
See also
Birds in Meitei culture
Animals in Meitei culture
Hills and mountains in Meitei culture
Keibu Keioiba
Kangla Sha
Nongshaba
Poubi Lai
Taoroinai
References
External links
Kings in Meitei mythology
Birds
Mythological monsters
History of Manipur
Animals in culture | Kakyen | [
"Biology"
] | 783 | [
"Birds",
"Animals"
] |
72,759,843 | https://en.wikipedia.org/wiki/Citlalli%20Gaona-Tiburcio | Citlalli Gaona-Tiburcio is a Mexican materials scientist whose research interests include the treatment of metal-reinforced concrete for resistance to corrosion, and the development of composite materials for extreme environments including high-temperature and aerospace applications. She is a professor and researcher in the Center for Research and Innovation in Aeronautical Engineering, in the Faculty of Mechanical and Electrical Engineering of the Autonomous University of Nuevo León (UANL).
Education and career
Gaona-Tiburcio did her undergraduate studies in metallurgical engineering at UAM Azcapotzalco, graduating in 1993. She earned a master's degree in the subject from the National Autonomous University of Mexico in 1997, and completed a doctorate in 1999 through the Centro de Investigación en Materiales Avanzados (CIMAV).
She continued to work as a researcher for CIMAV from 1995 to 2011. In 2013 she took her present position as a professor and researcher at UANL.
Recognition
Gaona-Tiburcio is a member of the Mexican Academy of Sciences.
References
External links
Year of birth missing (living people)
Living people
Mexican engineers
Mexican women engineers
Materials scientists and engineers
Women materials scientists and engineers
Universidad Autónoma Metropolitana alumni
National Autonomous University of Mexico alumni
Academic staff of the Autonomous University of Nuevo León
Members of the Mexican Academy of Sciences | Citlalli Gaona-Tiburcio | [
"Materials_science",
"Technology",
"Engineering"
] | 272 | [
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology",
"Materials science"
] |
72,759,975 | https://en.wikipedia.org/wiki/Limonium%20sinense | Limonium sinense is a species of flowering plant in the sea lavender genus Limonium, family Plumbaginaceae, native to coastal China, Taiwan, the Ryukyu Islands, and Vietnam. It is a perennial reaching , found on sandy, salty shales next to the ocean. There are a large number of cultivars, with a wide variety of flower colors, created for the cut flower industry. Wild individuals have flowers with white sepals and yellow petals.
References
sinense
Halophytes
Garden plants
Flora of Manchuria
Flora of North-Central China
Flora of Southeast China
Flora of Taiwan
Flora of the Ryukyu Islands
Flora of Vietnam
Plants described in 1891 | Limonium sinense | [
"Chemistry"
] | 134 | [
"Halophytes",
"Salts"
] |
72,760,141 | https://en.wikipedia.org/wiki/2%20Cassiopeiae | 2 Cassiopeiae (2 Cas) is a white bright giant in the constellation Cassiopeia, about 2,800 light years away. It is a chemically peculiar Am star.
2 Cassiopeiae has been described as an A4 type bright giant, but its spectrum is not easy to classify. The calcium K absorption lines indicate a hotter type than the hydrogen lines, while other metals indicate a cooler type, possibly as cool as F0. This makes it an Am star, a type of magnetic chemically peculiar star with unusual abundances showing in its spectrum due to chemical stratification in its atmosphere caused by slow rotation.
About six times as massive as the Sun and 3,000 times as luminous, it has expanded away from the main sequence after exhausting its core hydrogen and now has an effective temperature of about . Some researchers have suggested that it is a post-AGB star.
2 Cassiopeiae has a number of close companions listed in multiple star catalogues, but none are thought to be gravitationally associated.
References
A-type bright giants
Cassiopeia (constellation)
Cassiopeiae, 02
8822
218753
114365
BD+58 2552
Am stars | 2 Cassiopeiae | [
"Astronomy"
] | 248 | [
"Cassiopeia (constellation)",
"Constellations"
] |
72,760,269 | https://en.wikipedia.org/wiki/Buchwaldoboletus%20acaulis | Buchwaldoboletus acaulis is a species of bolete fungus in the family Boletaceae native to Lesser Antilles and Martinique. Found on wood in xero-mesophytic forests, it has a convex bright yellow cap, sulfur-yellow pores and stipe, and a brown spore print. Its edibility is unknown.
Taxonomy and naming
Originally described by David Pegler in 1983 as Pulveroboletus acaulis, it was given its current name by Ernst Both and Beatriz Ortiz-Santana in A preliminary survey of the genus Buchwaldoboletus, published in "Bulletin of the Buffalo Society of Natural Sciences" in 2011.
Description
The cap is bright yellow, convex, and measures in diameter. The flesh may stain blue where it has been cut or bruised. The pores are small, and the pore surface is sulphur-yellow to pinkish-brown in maturity, staining bluish with injury. The stipe is rudimentary, lateral to very excentric, same color as the cap. There is a yellow mycelium at the stipe base.
The mushroom produces a brown spore print. Spores measure 5.5–8 ×2.5–3.5 μm.
References
External links
Boletaceae
Fungi described in 1983
Fungi of the Caribbean
Fungus species | Buchwaldoboletus acaulis | [
"Biology"
] | 274 | [
"Fungi",
"Fungus species"
] |
72,760,567 | https://en.wikipedia.org/wiki/Buchwaldoboletus%20hemichrysus | Buchwaldoboletus hemichrysus is a species of bolete fungus in the family Boletaceae native to USA. Found on pine wood, it has a convex bright golden-yellow cap, rich red-brown pores, and an ochraceous spore print. It's edible, but the flesh is described as "tasteless".
Taxonomy and naming
Originally described by Miles Joseph Berkeley and Moses Ashley Curtis in 1873 as Boletus hemichrysus, it was given its current name by mycologist Albert Pilát in 1969. He placed it in the new genus Buchwaldoboletus on account of its occurrence on wood (rather than in the ground), decurrent and arcuate pores, the yellow mycelium at the base of the stipe, the blueing flesh and lack of hyphal clamps.
Description
The cap is bright golden yellow, convex, and can reach in diameter. The flesh may stain blue where it has been cut or bruised. The pores are small, and the pore surface is red-brown in maturity, staining bluish with injury. The stipe is irregular, varying in thickness, sometimes in diameter, yellowish tinted with red. There is a yellow mycelium at the stipe base.
The mushroom produces an ochraceous spore print. Spores measure 7–9.5 × 3–3.5 μm.
References
External links
Boletaceae
Fungi described in 1873
Fungi of North America
Fungus species
Taxa named by Miles Joseph Berkeley
Taxa named by Moses Ashley Curtis | Buchwaldoboletus hemichrysus | [
"Biology"
] | 319 | [
"Fungi",
"Fungus species"
] |
72,762,647 | https://en.wikipedia.org/wiki/List%20of%20nitrogen-fixing-clade%20families | The nitrogen-fixing clade consists of four orders of flowering plants: Cucurbitales, Fabales, Fagales and Rosales. This subgroup of the rosids encompasses 28 families of trees, shrubs, vines and herbaceous perennials and annuals. The roots of many of the species host bacteria that fix nitrogen into compounds the plants can use.
The trees of this subgroup dominate many temperate forests. Cannabis, with the psychoactive drug tetrahydrocannabinol (THC), has been used recreationally and ceremonially for at least 2400 years, but was in cultivation at least 6000 years before that for its oils and for making fabric and rope. Cucumbers, melons and watermelons are cultivated around the globe. The Mediterranean diet around 6000 years ago included fava beans, lentils, chickpeas and other legumes. Chestnuts were spread throughout Europe by the ancient Romans. The apple (in the rose family) is the second-most-cultivated sweet fruit, after the grape (in the order Vitales, not in this clade).
Glossary
From the glossary of botanical terms:
annual: a plant species that completes its life cycle within a single year or growing season
basal: attached close to the base (of a plant or an evolutionary tree diagram)
climber: a vine that leans on, twines around or clings to other plants for vertical support
deciduous: falling seasonally, as with bark, leaves or petals
herbaceous: not woody; usually green and soft in texture
perennial: not an annual or biennial
succulent (adjective): juicy or fleshy
unisexual: of one sex; bearing only male or only female reproductive organs
woody: hard and lignified; not herbaceous
Fabales is basal within the nitrogen-fixing clade. This clade, the COM clade and the order Zygophyllales constitute the fabids under the fourth Angiosperm Phylogeny Group (APG IV) system.
Families
See also
List of plant family names with etymologies
Notes
Citations
References
See the Creative Commons license.
See their terms-of-use license.
Systematic
Nitrogen-fixing-clade families
Nitrogen-fixing-clade families
nitrogen-fixing-clade families
Rosids | List of nitrogen-fixing-clade families | [
"Biology"
] | 465 | [
"Lists of biota",
"Lists of plants",
"Plants"
] |
72,763,167 | https://en.wikipedia.org/wiki/Amit%20Keren | Amit Keren (Hebrew: עמית קרן) is an Israeli Professor of Physics in the Department of Physics Technion-Israel Institute of Technology. He is an experimentalist investigating mostly the properties of magnetic and superconducting material.
He worked on compounds such as spin glasses, frustrated magnets, molecular magnets, and superconductors. He uses experiential techniques such as muon, electron, and nuclear spin resonance, magnetometers, transport, neutron scattering, various kinds of x-ray scattering and photoemission. He also operates a single crystal growth lab.
Education
Amit Keren received his B.Sc. in Physics and Mathematic in 1986 from Tel Aviv University, his doctorate in 1994 from Columbia University under the supervision of Tomo Uemura, and was a postdoctoral fellow at Orsay University Paris, under the supervisor of Henry Alloul until 1997.
Research work
Common energy scale for magnetism and superconductivity: The Keren group demonstrated experimentally that superconductivity and magnetism in the high temperature cuprate superconductors share a common energy scale, namely, the critical temperature and the superexchange interaction strength are proportional to each other. This finding is backed by many different experiments.
Mapping exotic spin correlations in spin glasses: Keren and collaborators found experimentally that close to the spin glass transition temperature, the field-time-dependent polarization of a probing spin scales like their ratio. They interpreted this behavior using power law correlation function.
Muon relaxation in a stochastic field environment: When a spin polarized muon enters a magnetic sample, it loses its polarization. The analytical relation between the muon polarization and the stochastic properties of the field is known as the Keren function.
Stiffnessometer: When the current in a very long coil, which pierces a superconducting ring, is turned on, a persistent current is generated in the ring. The amount of current depends on the superconductor stiffness. By measuring this current via the magnetic moment of the ring the stiffness can be determined. The Keren group developed an instrument based on these principles
References
External links
20th-century Israeli physicists
21st-century Israeli physicists
Columbia University alumni
Date of birth missing (living people)
Electrochemists
Israeli nuclear physicists
Israeli physical chemists
Living people
Academic staff of Technion – Israel Institute of Technology
Tel Aviv University alumni
Year of birth missing (living people) | Amit Keren | [
"Chemistry"
] | 513 | [
"Electrochemistry",
"Electrochemists"
] |
72,764,724 | https://en.wikipedia.org/wiki/Polyoxetane | Polyoxetane (POX), or poly(oxetane), is synthetic organic heteroatomic thermoplastic polymer with molecular formula (–OCH2CH2CH2–)n. It is polymerized from oxetane monomer, which is a four-membered cyclic ether.
History
Needed chemistry was observed and developed through the 1930s and 1940s. The very first polymerized oxetane was 3,3-bis(chloromethyl)oxetane followed by other 3,3-disubstituted derivatives during the 1950s. Unsubstituted oxetane itself was polymerized in 1956.
Monomers
Tens of oxetane derivatives have been synthesized and many of them are polymerizable. Reasons for inability to polymerize are different basicity and ring strain caused by different electron and bulkiness of substituents also as their position. Major 3-substituted and 3,3-disubstituted monomers are summarized in the oxetane article.
Polymerization
Mechanism
Ring strain of unsubstituted oxetane is 107 kJ/mol. That is twenty times more, than non-polymerizable six-membered tetrahydropyran. Oxetane polymerizes via a cationic, ring-openning mechanism. Special oxetanes are polymerizable by other mechanisms.
The propagation centre is a tertiary oxonium ion, mainly initialized by Lewis acids, trialkyl oxonium salts, carbocationic salts and others. Strong acids tend to generate secondary oxonium ions, which are unreactive, thus they are not initiators of first choice. On the other hand super acids (eg. HSO3F) are effective initiators of cationic polymerization of cyclic ethers, such as oxetane. For sufficient stability of propagation centre, a counterion X– of low nucleophilicity is required, such as SbCl6–, PF6–, AsF6– or SbF6–. First polymerizations were conducted with compounds consisting of BF4– or BF3OH– counterions. Propagation is very fast and thus preparation of lower molecular weight products (also with desired functional end groups) wasnlt performed until today.
Side reactions
Unsymmetrically substituted oxetanes polymerizes according to ability of attacking one or both alpha-carbons of the propagation centre. Unsubstituted and 3-substituted derivatives polymerize in symmetrical manner, but 2-substituted derivatives can form any of the basic types of polymer chain connections (head-to-tail, head-to-head and tail-to-tail). However, with right conditions and initiation system used, a stereospecific propagation can be achieved.
Oxygen atoms of the main chain possess enough reactivity to attack oxonium propagation centre to either form cyclic oligomers (usually tetramers) or to depolymerize.
These reactions within one molecule are referred as backbitting. During polymerization of unsubstituted oxetane, mutual attack of two growing chains may occur, in very small number, to form acyclic oxonium ions. This process is so called temporary termination.
Mentioned side reactions compete in speed with propagation. The faster the propagation, the less side reactions take place. Speed of propagation depends on polymerized monomer, initiation system used and polymerization conditions set.
Example of industrial production
Polymerization is conducted in mixture of methylene chloride and petrol in -25 °C for 4 to 8 hours to obtain suspension of polymer. Catalytic system consists of 1-2 % BF3 and 0,1-0,4 % epichlorhydrin which acts as a cocatalyst. Final suspension is neutralised, stripped by water steam, filtered, washed and dried.
Substituted polyoxetanes
A series of substituted oxetanes have been synthesized and polymerized. The very first polymerized oxetane was 3,3-bis(chloromethyl)oxetane.
Properties
Polyoxetanes can be liquids or solids with high range of crystallinity and melting temperature. Final material characteristics depend on symmetry, bulkiness and polarity of the substituents. For example, melting temperature of POX is 35 °C. One methyl substituent in position 2 or 3 ensures amorphous character of polymethyloxetanes. Oxetanes symmetrically bisubstituted on the same carbon, give crystalline polymers, such as 3,3-dimethyloxetane. Melting point of poly(3,3-dimethyloxetane) is 47 °C. Halogens increase melting point of oxetane polymers. The bigger halogen atom, the higher melting temperature is. Melting temperature of halogenated oxetanes vary from 135 to 290 °C. Amorphous low melting oxetanes are soluble in common organic solvents, on the other hand crystalline are not.
Polymeranalogical reaction
Butyllithium has been used to break up polyoxetane to lower molecular weight POX glycols with hydroxyl (–OH) functional end groups. With the same result, degradation with ozone followed by reduction by LiAlH4 can be used. Polyoxetane glycols can be used for manufacturing of polyurethane networks and preparation of copolymers.
Copolymers
Two main reasons to copolymerize oxetanes are adjustment of crystallinity and modification of material properties.
Oxetanes are copolymerized mainly with tetrahydrofuran (THF) to produce precursors of soft segments of polyurethanes (PUR), polyethers and polyamide elastomers. Particularly statistic copolymer of BCMO and THF is amorphous, tough rubber. Unhomopolymerizable derivatives of oxetane are able to copolymerize with homopolymerizable oxetanes. Most studied monomer in copolymerization problemstics have been BCMO. Also copolymers with thermoplastic elastomer behavior have been prepared.
Applications
Polyoxetanes are engineering polymers. Only one oxetane polymer, derived from 3,3–bis(chloromethyl)oxetane (BCMO) had industrial application. It was available under trade mark Penton by Hercules, Inc. (USA) and Pentaplast (Russia). Main use were sterilizable goods because of relatively high heat-distortion temperature and low water absorption. BCMO is self extinguishing (because of chlorine atoms present in polymer chain) and is highly chemically resistant. It stands up to most organic solvents and strong alkali. It dissolves in strong acids, such as concentrated HNO3 or H2SO4. A typical number-average molecular weight range between 250 000 and 350 000 g/mol. It can be conventionally processed via injection moulding. Moulded goods exhibit low shrinkage and fantastic dimensional stability in general.
Examples of parts that can be constructed from costly PBCMO are bearings, valves, parts for fitting cables and electrical parts, etc. It is a very good anti-corrosive coating with guarantee of corrosive stability with main use for chemical tanks. It's great material for desalination membranes. Perfluorinated oxetanes (–CF2CF2CF2O–)n exhibit great friction-reducing properties and are potentially useful for gas separation membranes
Significant part of oxetanes are turned into polyoxetanes glycols and other polymeric materials.
Energetic polymers
By replacing hydrogen(s) in position 3 by electron deficient groups, energetic polymers can be prepared. Desired functional groups are ethyl (CH3–CH2–), nitro (NO2–) or 2-oxa-4,4-dinitropentyl (CH3–C(NO2)2–CH2–O–CH2–). Energetic polymers can be used as explosives and propellants or they are precursors for manufacturing of mentioned above. They burn with a great deal of smoke.
References
Polymers
Polyethers | Polyoxetane | [
"Chemistry",
"Materials_science"
] | 1,702 | [
"Polymers",
"Polymer chemistry"
] |
72,765,117 | https://en.wikipedia.org/wiki/Limonium%20tetragonum | Limonium tetragonum, the square-stalked sea lavender, is a species of flowering plant in the family Plumbaginaceae. It is native to Primorsky Krai in Russia, South Korea, central and southern Japan, the northern Ryukyu Islands, and New Caledonia some away. A biennial halophyte, it can be found growing at the high tide line in coastal wetlands and in salt marshes. It is collected in the wild and eaten as a vegetable, and is considered to have medicinal properties. There appears to be an ornamental cultivar, 'Confetti'.
References
tetragonum
Halophytes
Flora of Primorsky Krai
Flora of South Korea
Flora of Japan
Flora of the Ryukyu Islands
Flora of New Caledonia
Plants described in 1949 | Limonium tetragonum | [
"Chemistry"
] | 159 | [
"Halophytes",
"Salts"
] |
75,574,827 | https://en.wikipedia.org/wiki/Boletellus%20deceptivus | Boletellus deceptivus is a species of bolete fungus in the family Boletaceae. Found in eastern Australia and Papua New Guinea.
References
External links
deceptivus
Fungi described in 2015
Fungi of Australia
Fungus species | Boletellus deceptivus | [
"Biology"
] | 48 | [
"Fungi",
"Fungus species"
] |
75,575,835 | https://en.wikipedia.org/wiki/Gretchen%20Goldman | Gretchen Goldman is an American environmental scientist and policy advocate. She is currently the climate change research and technology director at the U.S. Department of Transportation. She served between 2021 and 2023 as the assistant director for environmental science, engineering, policy, and justice for the White House Office of Science and Technology Policy. Through a viral tweet and her work with 500 Women Scientists, she has also become known as an advocate for working mothers in the STEM fields.
Education
Goldman earned a bachelor's degree in Atmospheric Science at Cornell University in 2006. She then went on to earn a master's and PhD in Environmental Engineering at Georgia Tech in 2008 and 2011 respectively.
Career
Following a postdoc at Georgia Tech, Goldman served for 10 years as research director for the Center for Science and Democracy at the Union of Concerned Scientists, where she led research efforts at the intersection of science and policy. In this role, she led research in environmental justice, fossil fuels, climate change, energy production, and scientific integrity. She has testified before Congress and offered proposals that have been adopted by the Biden Administration. She also served as an expert on the Public Health Rulemaking of the California Department of Conservation's Geologic Energy Management Division. Additionally, Goldman chaired the Air and Climate Public Advisory Committee for the Metropolitan Washington Council of Governments and she served in the UNESCO/AAAS Consultation Group.
Goldman is also a member of the board of 500 Women Scientists. Through this group, she has worked to support working mothers in STEM fields during the pandemic. In an attempt to raise awareness for the struggles faced by mothers working from home, Goldman posted what became a viral tweet that brought attention to the cause. It showed the chaotic reality of the home office she was using during an online video conference. She continues to fight to protect women's opportunities in the workplace.
She has been quoted and featured in many news outlets including The Washington Post, The New York Times, Science, Nature, CNN, BBC, and NPR.
Personal life
Goldman has two sons.
List of works
Goldman, GT, A Desikan, R Morse, C Kalman, T MacKinney, DS Cohan, G Reed, J Parras. 2021. Assessment of Air Pollution Impacts and Monitoring Data Limitations of a Spring 2019 Chemical Facility Fire. Environmental Justice. doi: 10.1089/env.2021.0030.
Carter, JM; Goldman, GT; Rosenberg, AR; Reed, G; Desikan, A; MacKinney, T. 2021. Strengthen scientific integrity under the Biden administration. Science. 371 (6530) 668-671. doi: 10.1126/science.abg0533
Goldman, GT, J Carter, Y Wang, JM Larson. 2020. Perceived losses of scientific integrity under the Trump administration: A survey of federal scientists. PLoS ONE 15(4):e0231929. doi: 10.1371/journal.pone.0231929
Declet-Barreto, J, GT Goldman, A Desikan, E Berman, J Goldman, C Johnson, L Montenegro, AA Rosenberg. 2020. Hazardous air pollutant emissions implications under 2018 guidance on U.S. Clean Air Act requirements for major sources. J of Air and Waste Management. doi: 10.1080/10962247.2020.1735575
Goldman, GT, F Dominici. 2019. Don’t abandon evidence and process on air pollution policy. Science. March 29. 363 (6434) 1398-1400 DOI: 10.1126/science.aaw9460.
Goldman, GT, E Berman, M Halpern, C Johnson, Y Kothari, G Reed, and AA Rosenberg. 2017. Ensuring Scientific Integrity in the Age of Trump. Science. February 17. 355 (6326). DOI: 10.1126/science.aam5733.
Goldman, GT, K Mulvey, P Frumhoff, R Sethi, S Pfirman, and H Commoss. 2017. A Methodology for Assessment of Corporate Responsibility on Climate Change: A Case Study of the Fossil Energy Industry. Journal of Environmental Investing. September 22.
Carroll, C, B Hartl, GT Goldman, DJ Rohlf, A Treves, JT Kerr, EG Ritchie, RT Kingsford, KE Gibbs, M Maron, JEM Watson. 2017. Defending the Scientific Integrity of Conservation-Policy Processes. Conservation Biology. July 25. DOI: 10.1111/cobi.12958.
Strickland, MJ.; KM Gass; GT Goldman; JA Mulholland. 2015. Effects of ambient air pollution measurement error on health effect estimates in time series studies: a simulation-based analysis. Journal of Exposure Science and Environmental Epidemiology, doi: 10.1038/jes.2013.16.
Rosenberg A, Phartiyal P, Goldman G, Branscomb L. 2014. Exposing Fracking to Sunlight. Issues in Science and Technology 31(1):74-79.
Goldman, GT; Mulholland, JA; Russell, AG; Gass, K; Strickland, MJ; Klein, M; Tolbert, PE. 2012. Characterization of Ambient Air Pollution Measurement Error in a Time-Series Health Study using a Geostatistical Simulation Approach. Atmospheric Environment. 57, 101-108.
Goldman, GT; Mulholland, JA; Russell, AG; Strickland, MJ; Klein, M; Tolbert, PE; Waller, L; Edgerton, E. 2011. Impact of Exposure Measurement Error in Air Pollution Epidemiology: Effect of Error Type in Time-Series Studies. Environmental Health.10:61.
Goldman, GT; Mulholland, JA; Russell, AG; Srivastava, A; Strickland, MJ.; Klein, M; Tolbert, PE; Waller, L; Edgerton, E. 2010. Ambient Air Pollutant Measurement Error: Characterization and Impacts in a Time-Series Epidemiologic Study in Atlanta. Environmental Science & Technology. 44 (19) 7692-7698.
References
Living people
Cornell University alumni
American scientists
American women scientists
American science communicators
Environmental scientists
Georgia Tech alumni
Year of birth missing (living people) | Gretchen Goldman | [
"Environmental_science"
] | 1,311 | [
"American environmental scientists",
"Environmental scientists"
] |
75,575,899 | https://en.wikipedia.org/wiki/Photochemical%20action%20plots | Photochemical action plots are a scientific tool used to understand the effects of different wavelengths of light on photochemical reactions. The methodology involves exposing a reaction solution to the same number of photons at varying monochromatic wavelengths, monitoring the conversion or reaction yield of starting materials and/or reaction products. Such global high-resolution analysis of wavelength-dependent chemical reactivity has revealed that maxima in absorbance and reactivity often do not align. Photochemical action plots are historically connected to (biological) action spectra.
Historical development
The study of biological responses to specific wavelengths dates back to the late 19th century. Research primarily focused on assessing photodamage from solar radiation using broad-band lamps and narrow filters. These studies quantified effects such as cell viability, production of erythema, vitamin D3 degradation, DNA changes, and skin cancer appearance. The first biological action spectrum was recorded by Engelmann, who used a prism to produce different colors of light and then illuminated cladophora in a bacteria suspension. He discovered the effects of different light wavelengths on photosynthesis, marking the first recorded action spectrum of photosynthesis.
Critical evaluations of active wavelength regions in these studies helped identify contributing chromophores to processes such as photosynthesis. These chromophores are key for converting solar energy into chemical energy, with their absorption closely matching the rate of photosynthesis, usually determined by oxygen production or carbon fixation. This correlation led to the discovery of chlorophyll as a key chromophore in plant growth. Such studies have also been instrumental in identifying DNA as the core genetic material, key wavelengths leading to skin cancer, the transparent optical window of biological tissue, and the influence of color on circadian rhythms.
In the late 20th century, action spectra became essential in developing optical devices for photocatalysis and photovoltaics, particularly in measuring photocurrent efficiency at various wavelengths. These studies have been vital in understanding primary contributors to photocurrent generation, leading to advancements in materials, morphologies, and device designs for improved solar energy capture and utilization.
In photochemistry, action spectra have been mainly used in photodissociation studies. These involve a monochromatic light source, often a laser, coupled with a mass spectrometer to record wavelength-dependent ion dissociation in gaseous phases. These spectra help identify contributing chromophores in molecular systems, characterize radical generation and unstable isomers, and understand higher state electron dynamics.
The field underwent a transformation when a team led by Barner-Kowollik and Gescheidt recorded the first modern-day photochemical action plot using a tuneable monochromatic nanosecond pulsed laser system, discovering a strong mismatch between photochemical reactivity and absorptivity and marking a critical advancement in mapping wavelength-dependent conversions in photoinduced polymerizations. Following this, numerous photochemical action plots have been recorded in various molecular and polymerization systems.
Experimental setup
Key differences between traditional (biological) action spectra and modern photochemical action plots lie in the precision resolution of wavelengths (monochromaticity) and that an exact number of photons at each wavelength is applied coupled with the fact that covalent bond forming reactions were investigated for the first time.In the field of photochemical analysis, it is common to measure the extinction of chemicals with high precision, often at the sub-nanometer scale, using UV/Vis spectroscopy. To understand fundamental relationships between a chemical's absorbance and its photoreactivity, a detailed analysis of the reactivity at a similar level of resolution is required. Traditional methods using broadly emitting light sources or filters have inherent limitations in resolving true wavelength dependence in photoreactivity. To record an action plot, a wavelength-tuneable laser system is employed, capable of delivering a stable number of photons at each wavelength. The photoreactive reaction mixture is divided into aliquots and subjected to monochromatic light independently. The photochemical process' yield or conversion is subsequently measured using sensors like UV-Vis absorption or nuclear magnetic resonance (NMR) frequency changes.
Findings and implications
A key finding of modern photochemical action plots is that the absorption spectrum of a photoreactive molecule or reaction mixture correlates poorly with photochemical reactivity as a function of wavelength in many cases. Initial studies showed a significant red-shift in photopolymerization yield compared to the absorption spectrum of the employed photoinitiators, which showed extremely low absorptivity in those regions. This mismatch between absorption spectra and photochemical action plots has by now been observed in a wide array of photoreactive systems. A prominent example is the photoinduced [2+2] cycloaddition of the stilbene derivative, styrypyrene, which exhibited an 80 nm discrepancy between the action plot and absorption spectrum. Current research focuses on understanding the reasons behind these frequently observed mismatches.
For photochemical applications, the consequences of the absorptivity/reactivity mismatch are far reaching, as only photochemical action plots can reveal the most effective wavelength for a given process, moving away from the past paradigm that absorption spectra provide guidance for selecting the most effective wavelength.
References
Scientific techniques
Scientific terminology
Tools
Photosynthesis | Photochemical action plots | [
"Chemistry",
"Biology"
] | 1,089 | [
"Biochemistry",
"Photosynthesis"
] |
75,576,823 | https://en.wikipedia.org/wiki/Artificial%20planet | An artificial planet (also known as a planetary replica or a replica planet) is a proposed stellar megastructure. Its defining characteristic is that it has sufficient mass to generate its own gravity field that is strong enough to prevent atmosphere from escaping, although the term has been sometimes used to describe other types of megastructures that have self-sufficient ecosystems. The concept can be found in many works of science-fiction.
In science
Replica planet
Mark Hempsell suggested that an artificial replica planet could be created in the Solar System as preparation for future space colonization, probably in the habitable zone between the orbits of Venus and Mars. It could evolve from the construction of a smaller space habitat. They would have similar purpose to other large scale megastructures intended as living spaces (such as O'Neill cylinder) or the concept of colonizing (or terraforming) existing planets. Unlike a space habitat, the artificial planet would be large enough to create its own gravity field that would prevent its atmosphere from escaping, and atmosphere would also serve to protect the world from radiation or meteorites. However, an artificial planet would have a much worse mass invested to usable surface area ratio.
Material for artificial planet construction could be extracted from stars or gas giants or from asteroid mining. A sufficiently advanced civilization could use those resources to mass-produce artificial planets using a stellar factory that itself would likely be the size of a large planet.
Construction of an artificial planet has been described as scientifically plausible but likely taking thousands of years and would be highly expensive. It has also been suggested that such an endeavour would be more challenging than terraforming existing planets, although both ideas are mostly speculative at this point of human history.
Other
The term artificial planet has also been used to describe other types of megastructures, such as large spherical space stations. D. R. Glover defined artificial planet as "a self-sufficient, independent ecosystem in space", noting that size of such an entity is less relevant and that it could be much smaller than what is traditionally defined as a planet. Glover sees development of such a station as a precursor step for development of ships capable of interstellar travel.
Paul Birch has used this term to describe a concept of a supramundane planet. Such a structure would resemble the concept of a Dyson sphere, as the habitable surface would exist on the inner side, but it would be built around a massive stellar body, such as a giant planet or a black hole.
In fiction and popular culture
The concept of artificial planet can be found in many works of science fiction. An artificial planet is the main setting of several science fiction series, such as Philip José Farmer's Riverworld series (1971–1983), Jack L. Chalker's Well World series (1977-2000) and Paul J. McAuley's Confluence trilogy (1997-1999). Iain Banks' novel Matter (2008) is set on a shellworld (an artificial planet with several habitable layers).
The concept of artificial planets is also found in, among others, The Hitchhiker’s Guide to the Galaxy franchise created by Douglas Adams, where one of the characters is a "planet designer". The Death Star from the Star Wars franchise has been called an artificial planet as well.
In the 2000 film Titan A.E., a groundbreaking scientific project known as "The Titan Project", was designed to create new man-made, habitable planets in space.
See also
Atherton: The House of Power
Dyson sphere
Generation ship
Ringworld
Shellworld
References
Megastructures
Space habitats | Artificial planet | [
"Technology"
] | 734 | [
"Exploratory engineering",
"Megastructures"
] |
75,577,057 | https://en.wikipedia.org/wiki/Nihad%20Nusseibeh | Nihad Nusseibeh (1926–1999) was a Palestinian military engineer and Fatah member. He was one of the military advisers to Yasser Arafat, president of the Palestine Liberation Organization (PLO).
Biography
Nusseibeh was born in Jerusalem in 1926. He hailed from a leading family. He joined the Palestinian resistance movement at age 16. He was a graduate of the Military Engineering College of the Syrian Army where he graduated in 1948. He fought in the Golan Height battles in the 1950s and became a major after the battles. He was appointed commander of the northern sector of the Golan Front in 1959.
Nusseibeh settled in Jordan in 1964 and joined the Fatah. He was named as the commander of the Detection Department in the Fatah's military training unit and led the Fatah operations. He was made the commander of the Police Force in 1970. He became the PLO leader in Jordan in 1971 when the Palestinian forces left the country after the Black September events. Nusseibeh's tenure ended in 1979. He was promoted to major general and was named as the military advisor of Yasser Arafat in 1982.
Nusseibeh died on 18 December 1999.
References
1926 births
1999 deaths
Palestinian expatriates in Jordan
People from Jerusalem
Arab people in Mandatory Palestine
Major generals
Fatah members
Military engineers
Palestinian engineers | Nihad Nusseibeh | [
"Engineering"
] | 277 | [
"Military engineers",
"Military engineering"
] |
75,578,347 | https://en.wikipedia.org/wiki/AltStore | AltStore is an alternative app store for the iOS and iPadOS mobile operating systems, which allows users to download applications that are not available on the App Store, most commonly tweaked apps, jailbreak apps, and apps including paid apps on the app store. It was publicly announced on September 25, 2019, and launched on September 28.
History
Riley Testut is an American developer who began to work on AltStore after Apple declined to allow his Nintendo emulator Delta on the App Store. Since Xcode allowed him to temporarily install his Delta app to his iOS device for 7 days of testing, he created AltStore in 2019 to replicate this functionality, which could be extended to other .ipa files. As of 2022, AltStore had been downloaded 1.5 million times.
Features
AltStore exploits a loophole in the Xcode developer platform, which allows developers to sideload their own apps which they are working on without needing to jailbreak. Sideloaded apps are signed like a developer project for testing and will expire after 7 days with a free account or one year with a paid developer account, by which they will need to be refreshed or reinstalled.
References
Further reading
External links
Notes
1.AltStore PAL is only available on iPhone.
Application software
IOS software
Mobile software distribution platforms | AltStore | [
"Technology"
] | 271 | [
"Mobile content",
"Mobile software distribution platforms"
] |
75,579,307 | https://en.wikipedia.org/wiki/Transition%20metal%20complexes%20of%20thiocyanate | Transition metal complexes of thiocyanate describes coordination complexes containing one or more thiocyanate (SCN−) ligands. The topic also includes transition metal complexes of isothiocyanate. These complexes have few applications but played significant role in the development of coordination chemistry.
Structure and bonding
Hard metal cations, as classified by HSAB theory, tend to form N-bonded complexes (isothiocyanates), whereas class B or soft metal cations tend to form S-bonded thiocyanate complexes. For the isothiocyanates, the M-N-C angle is usually close to 180°. For the thiocyanates, the M-S-C angle is usually close to 100°.
Homoleptic complexes
Most homoleptic complexes of NCS− feature isothiocyanate ligands (N-bonded). All first-row metals bind thiocyanate in this way. Octahedral complexes [M(NCS)6]z- include M = Ti(III), Cr(III), Mn(II), Fe(III), Ni(II), Mo(III), Tc(IV), and Ru(III). Four-coordinated tetrakis(isothiocyanate) complexes would be tetrahedral since isothiocyanate is a weak-field ligand. Two examples are the deep blue [Co(NCS)4]2- and the green [Ni(NCS)4]2-.
Few homoleptic complexes of NCS− feature thiocyanate ligands (S-bonded). Octahedral complexes include [M(SCN)6]3- (M = Rh and Ir) and [Pt(SCN)6]2-. Square planar complexes include [M(SCN)4]z- (M = Pd(II), Pt(II), and Au(III)). Colorless [Hg(SCN)4]2- is tetrahedral.
Some octahedral isothiocyanate complexes undergo redox reactions reversibly. Orange [Os(NCS)6]3- can be oxidized to violet [Os(NCS)6]2-. The Os-N distances in both derivatives are almost identical at 200 picometers.
Linkage isomerism
Thiocyanate shares its negative charge approximately equally between sulfur and nitrogen. Thiocyanate can bind metals at either sulfur or nitrogen — it is an ambidentate ligand. Other factors, e.g. kinetics and solubility, sometimes influence the observed isomer. For example, [Co(NH3)5(NCS)]2+ is the thermodynamic isomer, but [Co(NH3)5(SCN)]2+ forms as the kinetic product of the reaction of thiocyanate salts with [Co(NH3)5(H2O)]3+.
Some complexes of SCN− feature both but only thiocyanate and isothiocyanate ligands. Examples are found for heavy metals in the middle of the d-period: Ir(III), and Re(IV).
SCN-bridged complexes
As a ligand, [SCN]− can also bridge two (M−SCN−M) or even three metals (>SCN− or −SCN<). One example of an SCN-bridged complex is [Ni2(SCN)8]4-.
Mixed ligand complexes
This article focuses on homoleptic complexes, which are simpler to describe and analyze. Most complexes of SCN−, however are mixed ligand species. Mentioned above is one example, [Co(NH3)5(NCS)]2+. Another example is [OsCl2(SCN)2(NCS)2]2-. Reinecke's salt, a precipitating agent, is a derivative of [Cr(NCS)4(NH3)2]−.
Applications and occurrence
Thiocyanate complexes are not widely used commercially. Possibly the oldest application of thiocyanate complexes was the use of thiocyanate as a test for ferric ions in aqueous solution. The reverse was also used: testing for the presence of thiocyanate by the addition of ferric salts. The 1:1 complex of thiocyanate and iron is deeply red. The effect was first reported in 1826. The structure of this species has never been confirmed by X-ray crystallography. The test is largely archaic.
Copper(I) thiocyanate is a reagent for the conversion of aryl diazonium salts to arylthiocyanates, a version of the Sandmeyer reaction.
Since thiocyanate occurs naturally, it is to be expected that it serves as a substrate for enzymes. Two metalloenzymes, thiocyanate hydrolases, catalyze the hydrolysis of thiocyanate. A cobalt-containing hydrolase catalyzes its conversion to carbonyl sulfide:
A copper-containing thiocyanate hydrolase catalyzes its conversion to cyanate:
In both cases, metal-SCN complexes are invoked as intermediates.
Synthesis
Almost all thiocyanate complexes are prepared from thiocyanate salts using ligand substitution reactions. Typical thiocyanate sources include ammonium thiocyanate and potassium thiocyanate.
An unusual route to thiocyanate complexes involves oxidative addition of thiocyanogen to low valent metal complexes:
, where Ph = C6H5
Even though the reaction involves cleavage of the S-S bond in thiocyanogen, the product is the Ru-NCS linkage isomer.
In another unusual method, thiocyanate functions as both a ligand and as a reductant in its reaction with dichromate to give [Cr(NCS)4(NH3)2]−. In this conversion, Cr(VI) converts to Cr(III).
Further reading
References
Inorganic chemistry
Transition metals
Coordination chemistry | Transition metal complexes of thiocyanate | [
"Chemistry"
] | 1,311 | [
"Thiocyanates",
"Coordination chemistry",
"Functional groups",
"nan"
] |
75,583,266 | https://en.wikipedia.org/wiki/Adidas%20miCoach | Adidas miCoach (stylized as adidas miCoach) was an Adidas subsidiary which was first announced as a pacer and smart watch on January 7 at the 2010 International Consumer Electronics Show.
Adidas miCoach was the parent of many products, including a video game, a fitness app, a pacer, a smart watch, and a performance center at the Ajax Youth Academy.
Video game
Adidas miCoach is a fitness/sports simulation game developed by Lightning Fish Games and Chromativity and published by 505 Games. It was released on July 13, 2012, in Europe, July 24, 2012, in North America, and July 26, 2012, in Australia for the Xbox 360 via Kinect and PlayStation 3 via PlayStation Move.
Gameplay
Adidas miCoach brought the miCoach interactive athletic training system to video game consoles. Players received real-time feedback on the actual in-game performance during their workouts when wearing a miCoach heart rate monitor.
Instead of faceless narrators or anonymous characters, Adidas miCoach makes use of digitized video footage of actual star athletes, such as Dwight Howard and Ana Ivanovic.
Adidas miCoach offers fitness training for specific sports across six disciplines. Users can train in basketball, association football, American football, tennis, running and rugby. There are also general fitness plans for both men and women.
Reception
Adidas miCoach received "mixed or average" reviews, according to review aggregator Metacritic.
Liam Martin on Digital Spy rated the game 3/5. Also stated that "Adidas miCoach lacks a little finesse, making it hard to recommend above superior fitness titles such as UFC Personal Trainer."
Ravi Sinha on GamingBolt rated the game 5/10 for the Xbox 360. Also stated that "Adidas miCoach isn’t fun, it isn’t responsive and while it means well with excessive content and features, it just doesn’t measure up to Kinect fitness game standards."
Play Sense rated the PlayStation 3 version of the game 3.5/10, stating that "The game uses the PlayStation Move and after calibrating, you would expect it to work well. However, the registration is pretty worthless." Also stating that "In conclusion, Adidas miCoach is a failure on almost every level."
Fitness app
The adidas miCoach app was a free fitness app that provides real-time audible training and sports-specific training programs. It was available for iOS, Android, and Windows.
The user could customize the app with the voice of an adidas athlete of their choice, such as David Villa.
The app could track the user's exercise and act as a personal trainer. It also provided GPS tracking, though pace and speed were calculated guesses without GPS. The app worked similarly to Nike+.
Discontinuation
In February 2017, Adidas announced it was discontinuing the miCoach platform. On February 28, 2018, it shut down the platform and passed the torch to Runtastic, but users were allowed migrate to Runtastic and get a free Premium membership. Adidas set up a transition service for miCoach users to migrate to Runtastic. Users could link their miCoach account to Runtastic and sync their workout data. All miCoach data from users was anonymized within Adidas systems and is no longer accessible (unless users had migrated to Runtastic). Data migration from the miCoach platform to the Adidas Running app is no longer feasible.
In September 2019, Runtastic rebranded its "Runtastic" app to "Adidas Running" and its "Results" app to "Adidas Training".
Smart watch
The Adidas miCoach Smart Run watch was announced on January 7, 2010, at the 2010 International Consumer Electronics Show and was released on in mid-August 2014 in North America, on August 15, 2014, worldwide.
The game and app were compatible with the discontinued Adidas miCoach Smart Run watch. The Adidas miCoach Smart Run was the sports company's first entry into the smartwatch market and is supposed to feel like a personal coach on your wrist than a simple activity tracker. The Smart Run is a stand-alone device and cannot be used with Adidas Running. It only worked with the Adidas miCoach app.
The miCoach replaced the need for a chest-mounted heart rate monitor, building it in directly beneath the watch, and also came with GPS and Bluetooth for an all-in-one running gadget. The company priced it at $199 and released in mid-August 2014 in the North America, and for the rest of the world on August 15, 2014, through Adidas' website, and on September 1 through Adidas Sports Performance stores.
Richard Trenholm on CNET stated that "Adidas's new high-tech timepiece does a lot more than the new Nike FuelBand SE. The FuelBand is a bracelet that records your activity and converts your exertions into NikeFuel points on the Nike+ website, but fitness fanatics are disappointed (as) the new bracelet doesn't feature a heart rate monitor. Still, its substantially cheaper than the Smart Run."
See also
Adidas
References
Adidas
GPS sports tracking applications
Fitness apps
Exercise equipment
IOS software
WatchOS software
Android (operating system) software
Windows Phone software
Xbox 360 games
PlayStation 3 games
Fitness games
Sports video games
Adidas video games
Kinect games
PlayStation Move-compatible games
2012 video games
505 Games games
Lightning Fish games | Adidas miCoach | [
"Technology"
] | 1,141 | [
"Global Positioning System",
"GPS sports tracking applications"
] |
75,584,466 | https://en.wikipedia.org/wiki/Bunkbed%20conjecture | The bunkbed conjecture (also spelled bunk bed conjecture) is a statement in percolation theory, a branch of mathematics that studies the behavior of connected clusters in a random graph. The conjecture is named after its analogy to a bunk bed structure. It was first posited by Pieter Kasteleyn in 1985. A preprint giving a proposed counterexample to the conjecture was posted on the arXiv in October 2024 by Nikita Gladkov, Igor Pak, and Alexander Zimin.
Description
The conjecture has many equivalent formulations. In the most general formulation it involves two identical graphs, referred to as the upper bunk and the lower bunk. These graphs are isomorphic, meaning they share the same structure. Additional edges, termed posts, are added to connect each vertex in the upper bunk with the corresponding vertex in the lower bunk.
Each edge in the graph is assigned a probability. The edges in the upper bunk and their corresponding edges in the lower bunk share the same probability. The probabilities assigned to the posts can be arbitrary.
A random subgraph of the bunkbed graph is then formed by independently deleting each edge based on the assigned probability.
Equivalently, it can be assumed that all edges have the same deletion probability .
Statement of the conjecture
The bunkbed conjecture states that in the resulting random subgraph, the probability that a vertex in the upper bunk is connected to some vertex in the upper bunk is greater than or equal to the probability that is connected to , the isomorphic copy of in the lower bunk.
Interpretation and significance
The conjecture suggests that two vertices of a graph are more likely to remain connected after randomly removing some edges if the graph distance between the vertices is smaller. This is intuitive, and similar questions for random walks and Ising model were resolved positively. The original motivation for the conjecture was its implication that, in a percolation on the infinite square grid, the probability of being connected to for is greater than the probability of being connected to .
Despite intuitiveness, proving this conjecture is not straightforward and is an active area of research in percolation theory. It was proved for specific types of graphs, such as wheels, complete graphs, complete bipartite graphs, and graphs with a local symmetry. It was also proved in the limit for any graph. Counterexamples for generalizations of the bunkbed conjecture have been published for site percolation, hypergraphs, and directed graphs.
References
Percolation theory
Disproved conjectures | Bunkbed conjecture | [
"Physics",
"Chemistry",
"Mathematics"
] | 507 | [
"Physical phenomena",
"Phase transitions",
"Percolation theory",
"Combinatorics",
"Statistical mechanics"
] |
75,585,731 | https://en.wikipedia.org/wiki/List%20of%20least%20massive%20black%20holes | Below there is a list of the least massive known black holes, sorted by increasing mass. The unit of measurement is the solar mass, equivalent to kg.
List
See also
Stellar black hole
List of most massive black holes
References
Lists of superlatives in astronomy
Black holes | List of least massive black holes | [
"Physics",
"Astronomy"
] | 55 | [
"Black holes",
"Physical phenomena",
"Astronomy-related lists",
"Physical quantities",
"Lists of superlatives in astronomy",
"Unsolved problems in physics",
"Astrophysics",
"Density",
"Stellar phenomena",
"Astronomical objects"
] |
71,260,974 | https://en.wikipedia.org/wiki/TZ%20Mensae | TZ Mensae is a binary star in the southern circumpolar constellation Mensa. The system has a combined maximum apparent magnitude of 6.19, placing it near the limit for naked eye visibility. Parallax measurements place the system at a distance of 403 light years. The radial velocity is small.
The components of TZ Mensae have stellar classifications of A0 V and A8 V, both indicating that they are ordinary A-type main-sequence stars. They have masses of , and radii of , respectively. The primary has an effective temperature of and a luminosity 40 times that of the Sun (). As for the companion, it has a temperature of 7,178 K. and a luminosity less than The rotation of both stars is apparently synchronous with the orbital period, with projected rotational velocities of respectively. The system is estimated to be 141 million years old.
The two components take about 8 days to revolve around each other in a relatively circular orbit. Since the inclination is close to (actually ), the two stars periodically pass in front of one another and it has been classified as a eclipsing binary, specifically the Algol type. If the brighter component is eclipsing the dimmer one, the brightness drops to 6.36. If vice versa, it drops to 6.87, which is below the limit for naked eye visibility.
References
Mensa (constellation)
A-type main-sequence stars
Algol variables
Eclipsing binaries
Mensae, TZ
Mensae, 31
CD-84 00063
039780
025776
2059 | TZ Mensae | [
"Astronomy"
] | 341 | [
"Mensa (constellation)",
"Constellations"
] |
71,260,980 | https://en.wikipedia.org/wiki/Heme%20transporter | A heme transporter is a protein that delivers heme to the various parts of a biological cell that require it.
Heme is a major source of dietary iron in humans and other mammals, and its synthesis in the body is well understood, but heme pathways are not as well understood. It is likely that heme is tightly regulated for two reasons: the toxic nature of iron in cells, and the lack of a regulated excretory system for excess iron. Understanding heme pathways is therefore important in understanding diseases such as hemochromatosis and anemia.
Heme transport
Members of the SLC48 and SLC49 solute carrier family participate in heme transport across cellular membranes (heme-transporting ATPase).
SLC48A1—also known as Heme-Responsive Gene 1 (HRG1)—and its orthologues were first identified as a heme transporter family through a genetic screen in C.elegans. The protein plays a role in mobilizing heme from the lysosome to the cytoplasm.
Deletion of the gene in mice leads to accumulation of heme crystals called hemozoin within the lysosomes of bone marrow, liver and splenic macrophages, but the gene is not known to be associated with human disease.
FLVCR1 was originally identified as the receptor for the feline leukemia virus, whose genetic disruption leads to anemia and disruption of heme transport. It appears to protect cells at the CFU-E stage by exporting heme to prevent heme toxicity. Rare homozygous mutations result in autosomal recessive posterior column ataxia with retinitis pigmentosa.
FLVCR2 is closely related to FLCVR1, and genetic transfection experiments indicate that it transports heme. Mutations in the gene are associated with proliferative vasculopathy and hydranencephaly-hydrocephaly syndrome (PVHH, also known as Fowler syndrome).
Related genes SLC49A3 and SLC49A4 are less well characterized functionally, although SLC49A4 is also known as Disrupted In Renal Cancer Protein 2 or RCC4 due to an association with renal cell cancer.
References
Proteins
Molecular biology stubs
Molecular biology | Heme transporter | [
"Chemistry",
"Biology"
] | 471 | [
"Biomolecules by chemical classification",
"Molecular and cellular biology stubs",
"Molecular biology stubs",
"Biochemistry stubs",
"Molecular biology",
"Biochemistry",
"Proteins"
] |
71,264,374 | https://en.wikipedia.org/wiki/Myrmecopterula%20velohortorum | Myrmecopterula velohortorum is a species of fungus in the family Pterulaceae. It is associated with fungi cultivating ants of the genus Apterostigma.
Taxonomy
M. velohortorum was originally classified as Pterula velohortorum by the American mycologist Bryn Tjader Mason Dentinger in 2014. Before being formally classified it was referred to in studies on fungus growing ants as ant cultivar G2 and was found in ant nests belonging to the Apterostigma dentigerum subclade.
It was placed in the new genus Myrmecopterula by the mycologists Caio A. Leal-Dutra, Bryn Tjader Mason Dentinger and Gareth W. Griffith in 2020.
Description
M. velohortorum is cultivated in hanging 'veiled gardens' where the mycelium forms a thin envelope which surrounds the fungal garden. Gardens are found hanging under logs or inside cavities within them or rarely found in cavities in the ground. A single hole may exist in the veil serving as the entrance to the nest. It is hypothesized that M. velohortorum descended from M. nudihortorum with the two species then taking different evolutionary paths due to co-evolving with ants engaged in varying behaviors. Such as the weaving of mycelial threads to produce the veil which the ants are hypothesized to engage in.
Similar species
Myrmecopterula moniliformis and Myrmecopterula nudihortorum are the only other named species belonging to the genus Myrmecopterula. These are also associated with cultivation by Apterostigma ants. Four other unnamed and poorly documented Myrmecopterula species are known.
References
Pterulaceae
Fungus species | Myrmecopterula velohortorum | [
"Biology"
] | 378 | [
"Fungi",
"Fungus species"
] |
71,264,376 | https://en.wikipedia.org/wiki/Myrmecopterula%20nudihortorum | Myrmecopterula nudihortorum is a species of fungus in the family Pterulaceae. It is associated with fungi cultivating ants of the genus Apterostigma.
Taxonomy
M. nudihortorum was originally classified as Pterula nudihortorum by the American mycologist Bryn Tjader Mason Dentinger in 2014. Before being formally classified it was referred to in studies on fungus growing ants as ant cultivar G4 and was found in ant nests belonging to the Apterostigma manni subclade.
It was placed in the new genus Myrmecopterula by the mycologists Caio A. Leal-Dutra, Bryn Tjader Mason Dentinger and Gareth W. Griffith in 2020.
Description
Unlike M. velohortorum (G2) which is cultivated in veiled hanging gardens, M. nudihortorum is cultivated in spongelike masses on the bottom of the garden cavity either under logs or in cavities excavated in the ground. The garden is not enveloped in or suspended by a woven veil. This nest building behaviour is more similar to that of lower attine ants which engage in cultivation of Lepiotaceous fungi belonging to the G3 group. However only one species of Apterostigma, Apterostigma auriculatum was documented as cultivating the G3 fungus.
Similar species
Myrmecopterula moniliformis and Myrmecopterula velohortorum are the only other named species belonging to the genus Myrmecopterula. These are also associated with cultivation by Apterostigma ants. Four other unnamed and poorly documented Myrmecopterula species are known.
References
Pterulaceae
Fungus species | Myrmecopterula nudihortorum | [
"Biology"
] | 365 | [
"Fungi",
"Fungus species"
] |
71,265,122 | https://en.wikipedia.org/wiki/UV%20Piscium | UV Piscium is a binary star system in the constellation of Pisces. With a peak apparent visual magnitude of 8.98, it is too faint to be visible to the naked eye. This is an eclipsing binary system that decreases to magnitude 10.05 during the primary eclipse, then to magnitude 9.54 with the secondary eclipse. It is located at a distance of 232 light years from the Sun based on parallax measurements, and is receding with a radial velocity of 6.5 km/s. The position of this star near the ecliptic means it is subject to lunar occultation.
This star was found to be variable by H. Huth in 1959. He determined it to be an eclipsing binary and published the first light curve with a period of . R. B. Carr in 1969 proposed this to be an Algol-type variable with a minor tidal distortion of the components, plus a large, anomalous asymmetry in the light curve. D. S. Hall in 1976 grouped it among the class of short-period RS CVn binaries. The following year, variable, non-thermal radio emission was detected coming from this system, the first such discovered for a short-period binary.
Daniel M. Popper in 1969 found a double-lined, G-type spectrum with both components showing emission in the H and K lines. In 1979, A. R. Sadik deduced the system is a detached binary and suggested a bright, hot spot may produce the observed asymmetry in the light curve. He found stellar classifications of G2V and K0IV for the primary and secondary components, respectively. With improved spectra, Popper found main sequence classes of G5 and K3 for the two stars. The presence of a prominence was deduced in 1992, and a flare of hydrogen alpha was observed the following year.
This is a close binary system with an orbital period of 0.86 days. The orbit is circular and the components are spinning rapidly in-sync with their orbital period. This rotation rate is making both stars magnetically active, with average magnetic field strengths of and for the primary and secondary, respectively. Magnetic activity cycles appear to be causing the orbital period to oscillate with a 61 year period. The primary is a G-type main-sequence star of about the same size and mass as the Sun, while the secondary is a smaller K-type main-sequence star. They are estimated to be about 4.6 billion years old.
References
Further reading
G-type main-sequence stars
K-type main-sequence stars
Algol variables
RS Canum Venaticorum variables
Spectroscopic binaries
Pisces (constellation)
Durchmusterung objects
007700
005980
Piscium, UV | UV Piscium | [
"Astronomy"
] | 573 | [
"Pisces (constellation)",
"Constellations"
] |
71,265,537 | https://en.wikipedia.org/wiki/Allyltrimethylsilane | Allyltrimethylsilane is the organosilicon compound with the formula (CH3)3SiCH2CH=CH2. The molecule consists of the trimethylsilyl group attached to allyl group. This colorless liquid is used in organic synthesis.
References
Reagents for organic chemistry
Trimethylsilyl compounds | Allyltrimethylsilane | [
"Chemistry"
] | 72 | [
"Functional groups",
"Trimethylsilyl compounds",
"Reagents for organic chemistry"
] |
71,266,648 | https://en.wikipedia.org/wiki/KDU-414 | The KDU-414 (Russian Корректирующая Двигательная Установка, Corrective Propulsion Unit), is a pressure-fed liquid rocket Propulsion Unit developed and produced by the Isayev Design Bureau (today known as KhimMash). From 1960 onward, it powered several unmanned Soviet Spacecraft, including the first series of Molniya satellites, several Kosmos satellites as well as the space probes Mars 1, Venera 1, Zond 2 and Zond 3, featured as a part of standardized spacecraft buses known as KAUR-2, 2MV and 3MV.
The Corrective Propulsion Unit consists of a single chamber 'S5.19' liquid rocket engine and a conical thermal protection cowl containing the spherical propellant tank.
A barrier splits the tank into two separate compartments, filled with the propellant, UDMH, and the oxidizer, IRFNA, respectively. This combination of propellants is hypergolic, igniting on contact.
The rocket motor is supplied with fuel by pressurizing the tank using gaseous nitrogen, which doubles as a source of RCS propellant.
Elastic barriers within the tank prevent the nitrogen gas and propellant/oxidiser from mixing with each other.
A gimbal mount allows the engine to swivel along two axes.
In 1974, it was replaced with its derived successor, the KDU-414A with the S5.114 engine.
References
External links
KB_KhimMash_rocket_engines
Rocket_engines
Rocket_engines_of_the_Soviet_Union
Rocket_engines_using_hypergolic_propellant
Rocket_engines_using_the_pressure-fed_cycle
Spacecraft attitude control | KDU-414 | [
"Technology"
] | 377 | [
"Rocket engines",
"Engines"
] |
71,267,518 | https://en.wikipedia.org/wiki/Setaphyta | The Setaphyta are a clade within the Bryophyta which includes Marchantiophytina (liverworts) and Bryophytina (mosses). Anthocerotophytina (hornworts) are excluded. A 2018 study found through molecular sequencing that liverworts are more closely related to mosses than hornworts, with the implication that liverworts were not among the first species to colonize land.
Phylogeny
There is strong phylogenetic evidence for Setaphyta.
References
Bryophytes
Plant unranked clades | Setaphyta | [
"Biology"
] | 119 | [
"Bryophytes",
"Plants"
] |
71,269,752 | https://en.wikipedia.org/wiki/Methyldiazonium | Methyldiazonium is an organic compound consisting of a methyl group attached to a diazo group. This cation is the conjugate acid of diazomethane, with an estimated pKa<10.
It is an intermediate in methylation reactions of diazomethane with acidic hydroxyl compounds, such as conversion of carboxylic acids to methyl esters and phenols to methyl ethers.
It has been implicated as the metabolite of N-nitrosodimethylamine responsible for the observed carcinogenicity of that compound.
References
Diazo compounds
Cations
Methylating agents
Methyl compounds | Methyldiazonium | [
"Physics",
"Chemistry"
] | 129 | [
"Matter",
"Methylating agents",
"Methylation",
"Cations",
"Ions",
"Organic chemistry stubs"
] |
71,271,852 | https://en.wikipedia.org/wiki/Leucoagaricus%20barssii | Leucoagaricus barssii, commonly known as the smoky dapperling, or gray parasol, is a species of fungus in the family Agaricaceae.
Taxonomy
Originally classified as Lepiota barssii by the American mycologist Sanford Myron Zeller in 1934 and reclassified as Leucoagaricus barssii by the mycologist Else C. Vellinga in 2000.
The type species of the Leucoagaricus genus, Leucoagaricus macrorhizus was reclassified as Leucoagaricus barssii.
Description
Leucoagaricus barssii is a large dapperling mushrooms with white flesh.
Cap: 4–8 cm. Starts convex before becoming depressed. May also present as slightly umbonate. It is fibrous with scattered scales. Stem: 4–8 cm. Tapers towards the base and possesses a wide annulus. Gills: White or cream in colour and attached freely with a collar. Spore print: creamy white. Spores: Ovoid and smooth. Dextrinoid. 7-8 x 5-5.5 μm. Taste: Indistinct. Smell: Pleasant and fresh.
Habitat and distribution
L. barssii is reported as being widespread but rarely recorded in the United Kingdom. Observations of it appear to be uncommon in Europe with the most common locations for purported observations being the West Coast of the United States.
References
barssii
Fungi described in 1934
Taxa named by Sanford Myron Zeller
Fungi of Europe
Fungi of North America
Fungus species | Leucoagaricus barssii | [
"Biology"
] | 322 | [
"Fungi",
"Fungus species"
] |
71,272,183 | https://en.wikipedia.org/wiki/Leucoagaricus%20meleagris | Leucoagaricus meleagris is a species of fungus in the family Agaricaceae.
Taxonomy
It was first described in 1799 by the British mycologist James Sowerby who classified it as Agaricus meleagris and illustrated it in volume II of Coloured Figures of English Fungi or Mushrooms'. Sowerby stated that the specimens were found in a hot-bed by Lady Arden on May 24, 1798.
In 1821, the species was reclassified as Gymnopus meleagris by the British mycologist Samuel Frederick Gray and the common name Turkey-fowl naked-foot was suggested.
In 1887, it was reclassified as Lepiota meleagris by the Italian mycologist Pier Andrea Saccardo.
In 1891, it was included in the German botanist Otto Kunze's exhaustive list of reclassifications as Mastocephalus biornatus, however Kunze's Mastocephalus genus, along with most of 'Revisio generum plantarum was not widely accepted by the scientific community of the age and so this classification was not accepted and nothing remains in this genus.
In 1936, it was reclassified as Hiatula meleagris by the German mycologist Rolf Singer and then as Leucocoprinus meleagris by Marcel Locquin in 1945. In 1949 Singer reclassified it as Leucoagaricus meleagris.
Sclerotia
Included in the taxonomy of this species by some sources is that of a Cenococcum species which was suspected to be an asexual morph of this species. However, there are issues with these classifications and it is not clear if this species actually produces sclerotia although some Leucoagaricus and Leucocoprinus species do.
In 1829, the Swedish mycologist Elias Magnus Fries described the novel species Cenococcum xylophilum which he described as being similar to Cenococcum geophilum in appearing like small black vetch seeds that are found beneath the soil. The exterior of C. xylophilum was noted as differing in the pale purple floccose (woolly) coating and the white-floury interior.
This was reclassified as Coccobotrys xylophilus in 1900 by the French mycologists Jean Louis Émile Boudier and Narcisse Théophile Patouillard who described the species as having ochre-yellow mycelium producing numerous round, 1-2mm wide structures with a hard outer surface of the same colour as the mycelium. When dissected there is a black layer beneath the exterior and then a red layer of a similar thickness beneath that, finally with a pale ochre centre that may tinge red or become whitish when dry. In this interior section are the sclerotic cells along with short hyphae similar to those surrounding the exterior. The species was found growing amongst tanbark in a hothouse in Angers, France that was growing palm trees.
In 1900, Charles van Bambeke classified Coccobotrys xylophilus as the mycelium and asexual morph of Lepiota meleagris. However the description of Coccobotrys xylophilus given by Boudier and Patouillard appears to significantly differ from that of Fries' Cenococcum xylophilum in colouration. Else Vellinga suggested that the material examined by Boudier and Patouillard and then later Bambeke was not the same as the original collection of Cenococcum xylophilum and so this reclassification had to be rejected. Coccobotrys chilensis however was reclassified as Leucoagaricus chilensis.
The description of the sclerotia given by Boudier and Patouillard may be similar to that of the sclerotia of Leucocoprinus birnbaumii.
Description
Leucoagaricus meleagris is a small dapperling mushrooms with white flesh in the cap and brown flesh in the stem.
Cap: 2–4.5 cm wide, starting hemispherical before expanding to campanulate (bell shaped) then plano-convex with a broad umbo. The surface background is white and covered with brownish-red coarse fibrils and scales. The surface discolours to a dirty red with age or when bruised. This can occur just from handling it. Stem: 6–8 cm long with a clavate taper up from the slightly wider base. The surface is white with a fibrillose coating and also discolours brownish-red when old or bruised. The white, ascending stem ring has reddish scales on the underside and is located towards the top of the stem (superior) but it may disappear. Gills: Free, crowded and white but discolouring like the rest of the mushroom so may be yellowish or brownish with age. Spore print: White. Spores: Ellipsoid with a somewhat thick wall and tiny germ pore. Smooth. Hyaline. Dextrinoid. 8-11 x 6-8 μm. Basidia: Four spored. Taste: Slightly farinaceous (floury). Smell: Indistinct.
Habitat and Distribution
Leucoagaricus meleagris grows in small groups and tufts in the Autumn. It is reported as being widespread but rarely recorded in the United Kingdom. In the early taxonomy of this species the observations are from greenhouses and amongst bark beds in hothouses so it may be more common in these warm environments. It has also been documented more recently from woodchips in England and Skåne, Sweden as well as in greenhouses in Warsaw, Poland. Observations of it appear to be uncommon in Europe with the most common locations for purported observations being the East Coast of the United States.
Similar species
Leucoagaricus americanus may appear similar, grow in the same human-made environments and exhibits similar yellow and then red staining when handled. These species may be confused in books. Leucoagaricus meleagris can be distinguished by the smaller size of the mushrooms and different cap surface.
References
meleagris
Taxa described in 1799
Taxa named by James Sowerby
Fungus species | Leucoagaricus meleagris | [
"Biology"
] | 1,314 | [
"Fungi",
"Fungus species"
] |
71,272,323 | https://en.wikipedia.org/wiki/Leucoagaricus%20nympharum | Leucoagaricus nympharum is a species of fungus in the family Agaricaceae.
Taxonomy
Originally classified as Agaricus nympharum by the Hungarian mycologist Károly Kalchbrenner in 1873 and reclassified as Leucoagaricus nympharum by the French mycologist Marcel Bon in 1977.
Description
Leucoagaricus nympharum is a large white dapperling mushroom with a distinctive scaly cap which resembles that of Chlorophyllum rhacodes only with a smaller, 4-10cm cap and a more starkly white colour. Despite its distinctive appearance it is seldom recorded and little known.
References
nympharum
Taxa described in 1873
Fungus species | Leucoagaricus nympharum | [
"Biology"
] | 151 | [
"Fungi",
"Fungus species"
] |
71,272,605 | https://en.wikipedia.org/wiki/Kaniadakis%20Gaussian%20distribution | The Kaniadakis Gaussian distribution (also known as κ-Gaussian distribution) is a probability distribution which arises as a generalization of the Gaussian distribution from the maximization of the Kaniadakis entropy under appropriated constraints. It is one example of a Kaniadakis κ-distribution. The κ-Gaussian distribution has been applied successfully for describing several complex systems in economy, geophysics, astrophysics, among many others.
The κ-Gaussian distribution is a particular case of the κ-Generalized Gamma distribution.
Definitions
Probability density function
The general form of the centered Kaniadakis κ-Gaussian probability density function is:
where is the entropic index associated with the Kaniadakis entropy, is the scale parameter, and
is the normalization constant.
The standard Normal distribution is recovered in the limit
Cumulative distribution function
The cumulative distribution function of κ-Gaussian distribution is given bywhereis the Kaniadakis κ-Error function, which is a generalization of the ordinary Error function as .
Properties
Moments, mean and variance
The centered κ-Gaussian distribution has a moment of odd order equal to zero, including the mean.
The variance is finite for and is given by:
Kurtosis
The kurtosis of the centered κ-Gaussian distribution may be computed thought:
which can be written asThus, the kurtosis of the centered κ-Gaussian distribution is given by:or
κ-Error function
The Kaniadakis κ-Error function (or κ-Error function) is a one-parameter generalization of the ordinary error function defined as:
Although the error function cannot be expressed in terms of elementary functions, numerical approximations are commonly employed.
For a random variable distributed according to a κ-Gaussian distribution with mean 0 and standard deviation , κ-Error function means the probability that X falls in the interval .
Applications
The κ-Gaussian distribution has been applied in several areas, such as:
In economy, the κ-Gaussian distribution has been applied in the analysis of financial models, accurately representing the dynamics of the processes of extreme changes in stock prices.
In inverse problems, Error laws in extreme statistics are robustly represented by κ-Gaussian distributions.
In astrophysics, stellar-residual-radial-velocity data have a Gaussian-type statistical distribution, in which the K index presents a strong relationship with the stellar-cluster ages.
In nuclear physics, the study of Doppler broadening function in nuclear reactors is well described by a κ-Gaussian distribution for analyzing the neutron-nuclei interaction.
In cosmology, for interpreting the dynamical evolution of the Friedmann–Robertson–Walker Universe.
In plasmas physics, for analyzing the electron distribution in electron-acoustic double-layers and the dispersion of Langmuir waves.
See also
Giorgio Kaniadakis
Kaniadakis statistics
Kaniadakis distribution
Kaniadakis κ-Exponential distribution
Kaniadakis κ-Gamma distribution
Kaniadakis κ-Weibull distribution
Kaniadakis κ-Logistic distribution
Kaniadakis κ-Erlang distribution
References
External links
Kaniadakis Statistics on arXiv.org
Probability distributions
Mathematical and quantitative methods (economics) | Kaniadakis Gaussian distribution | [
"Mathematics"
] | 668 | [
"Functions and mappings",
"Mathematical relations",
"Mathematical objects",
"Probability distributions"
] |
71,272,853 | https://en.wikipedia.org/wiki/Kaniadakis%20logistic%20distribution | The Kaniadakis Logistic distribution (also known as κ-Logisticdistribution) is a generalized version of the Logistic distribution associated with the Kaniadakis statistics. It is one example of a Kaniadakis distribution. The κ-Logistic probability distribution describes the population kinetics behavior of bosonic () or fermionic () character.
Definitions
Probability density function
The Kaniadakis κ-Logistic distribution is a four-parameter family of continuous statistical distributions, which is part of a class of statistical distributions emerging from the Kaniadakis κ-statistics. This distribution has the following probability density function:
valid for , where is the entropic index associated with the Kaniadakis entropy, is the rate parameter, , and is the shape parameter.
The Logistic distribution is recovered as
Cumulative distribution function
The cumulative distribution function of κ-Logistic is given by
valid for . The cumulative Logistic distribution is recovered in the classical limit .
Survival and hazard functions
The survival distribution function of κ-Logistic distribution is given by
valid for . The survival Logistic distribution is recovered in the classical limit .
The hazard function associated with the κ-Logistic distribution is obtained by the solution of the following evolution equation:with , where is the hazard function:
The cumulative Kaniadakis κ-Logistic distribution is related to the hazard function by the following expression:
where is the cumulative hazard function. The cumulative hazard function of the Logistic distribution is recovered in the classical limit .
Related distributions
The survival function of the κ-Logistic distribution represents the κ-deformation of the Fermi-Dirac function, and becomes a Fermi-Dirac distribution in the classical limit .
The κ-Logistic distribution is a generalization of the κ-Weibull distribution when .
A κ-Logistic distribution corresponds to a Half-Logistic distribution when , and .
The ordinary Logistic distribution is a particular case of a κ-Logistic distribution, when .
Applications
The κ-Logistic distribution has been applied in several areas, such as:
In quantum statistics, the survival function of the κ-Logistic distribution represents the most general expression of the Fermi-Dirac function, reducing to the Fermi-Dirac distribution in the limit .
See also
Giorgio Kaniadakis
Kaniadakis statistics
Kaniadakis distribution
Kaniadakis κ-Exponential distribution
Kaniadakis κ-Gaussian distribution
Kaniadakis κ-Gamma distribution
Kaniadakis κ-Weibull distribution
Kaniadakis κ-Erlang distribution
References
External links
Kaniadakis Statistics on arXiv.org
Probability distributions
Mathematical and quantitative methods (economics) | Kaniadakis logistic distribution | [
"Mathematics"
] | 547 | [
"Functions and mappings",
"Mathematical relations",
"Mathematical objects",
"Probability distributions"
] |
71,272,920 | https://en.wikipedia.org/wiki/Human%20Biomolecular%20Atlas%20Program | The Human Biomolecular Atlas Program (HuBMAP) is a program funded by the US National Institutes of Health to characterize the human body at single cell resolution, integrated to other efforts such as the Human Cell Atlas. Among the products of the program is the Azimuth reference datasets for single-cell RNA seq data and the ASCT+B Reporter, a visualization tool for anatomical structures, cell types and biomarkers.
Millitomes are used to create uniformly sized tissue blocks that match the shape and size of organs from HuBMAP's 3D Reference Object Library.
The HuBMAP received 27 million US dollars of funding from the NIH in 2020 and about 28.5 million in 2021.
References
External links
Official website
Biological databases
Proteomics
National Institutes of Health | Human Biomolecular Atlas Program | [
"Biology"
] | 164 | [
"Bioinformatics",
"Biological databases"
] |
71,273,423 | https://en.wikipedia.org/wiki/HD%2033142 | HD 33142 is a solitary 8th-magnitude red giant located about away in the southern constellation of Lepus. It is orbited by three confirmed exoplanets, namely the Jupiter-sized planets HD 33142 b and c, and a Saturn-like planet, d, located closer to the star.
Stellar characteristics
HD 33142 belongs to a class of "retired A stars," meaning it was likely once an A-type main-sequence star but has since evolved past the main sequence. Now, it is entering the red-giant branch with a spectral type of K0 III, a radius of 4.17 , and a mass of 1.52 . The effective temperature of HD 33142 is estimated to be about , giving it an orange color. The star is ten times as bright as the Sun, which, combined with its distance from Earth, places its apparent magnitude at 7.96, making it too faint to be visible by the naked eye under most circumstances, but it can be observed using binoculars. It has a solar-like metallicity of 0.06, which translates to an iron abundance 15% higher than the Sun. The star is aged approximately 2.72 billion years, making it three-fifths as old as the Solar System (4.568 billion years old).
The star's rotation period has been measured to be about 106 days from rotational broadening (i.e., Doppler broadening caused by the star's rotation), but this value is very uncertain as only the upper limit of the rotation velocity is known and the axial tilt is entirely undetermined. Light curves obtained by the TESS reveal no transit signals and suggest that the star is photometrically quiet. Archived data from Hipparcos photometry generally agree with this, with no indication of variability.
Planetary system
In 2011, Johnson et al. reported the discovery of a Jovian planet, HD 33142 b, alongside 17 other planets orbiting retired A stars. It revolves around the star in an Earth-like circular (eccentricity 0.049) orbit that lasts each, and has an estimated minimum mass of 1.26 .
The second planet, c, was discovered by Bryan et al. in 2016, and was initially described as a super-Jupiter with a minimum mass of 5.97 and an orbital period of . A 2019 follow-up study by Luhn et al., independently reported radial velocity signals that indicated the existence of a planet with a similar period of , but with a far smaller mass of 0.62 . A 2022 study by Trifonov et al. seems to agree more with the latter, confirming an 810-day period planet weighing at least 0.89 . Its orbit has a low eccentricity and a semi-major axis of 1.955 AU, roughly twice that of planet b.
In 2022, at the same time Trifonov et al. confirmed the previous two planets, they also reported another smaller object, d, with a mass of 64 , two-thirds that of Saturn (95 ). With a period of 89.9 days, an eccentricity of 0.191, and a semi-major axis of 0.452 AU, its orbit closely resembles that of Mercury, which has a period of 88.0 days, an eccentricity of 0.2056, and a semi-major axis of 0.3871 AU.
Stability and future
The HD 33142 system features massive planets in closely packed orbits, which makes it prone to orbital instability due to gravitational perturbations. While the system is presently stable, out of the 1,000 simulations conducted by Trifonov et al. with randomly generated initial conditions, one-third of them resulted in orbital destabilization within the million-year simulation span. For the unstable runs, the planetary system's median survival time was a mere 8,500 years.
Having left the main-sequence stage, HD 33142 is in the midst of developing into a red giant, and is expected to undergo two periods of rapid expansion in the next 300 million years: first during the red-giant branch, when it will reach a diameter of ~0.75 AU; and then in the asymptotic giant branch, ballooning to around 1.45 AU; all before ceasing nucleosynthesis and shriveling up into a white dwarf. In both phases, tidal forces from the bloated star cause orbital decay. According to simulations, the two inner planets, d and b, will be engulfed by the star before the tip of the red-giant branch as their orbits contract. The outermost planet, c, is predicted to survive the red-giant branch and migrate outward to ~2.5 AU, but will ultimately either succumb to the same fate during the asymptotic giant branch, or be ejected from the system entirely.
Notes
References
Lepus (constellation)
033142
023844
BD-14 01051
K-type giants
Planetary systems with three confirmed planets
J05073553-1359113 | HD 33142 | [
"Astronomy"
] | 1,040 | [
"Lepus (constellation)",
"Constellations"
] |
71,273,640 | https://en.wikipedia.org/wiki/Neodymium%28II%29%20bromide | Neodymium(II) bromide is an inorganic compound of neodymium and bromide.
Preparation
Neodymium(II) bromide can be obtained via the reduction of neodymium(III) bromide with neodymium in a vacuum at 800 to 900 °C.
Properties
Neodymium(II) bromide is a dark green solid. The compound is extremely hygroscopic and can only be stored and handled under carefully dried inert gas or under a high vacuum. In air or on contact with water, it converts to hydrates by absorbing moisture, but these are unstable and more or less rapidly transform into oxybromides with evolution of hydrogen. The compound has the same crystal structure as lead(II) chloride type.
References
Neodymium(II) compounds
Lanthanide halides
Bromides | Neodymium(II) bromide | [
"Chemistry"
] | 171 | [
"Bromides",
"Salts"
] |
71,273,648 | https://en.wikipedia.org/wiki/Ozark%20Highlands%20Spirits | Ozark Highlands Spirits refers to a category of distilled liquor codified by the Missouri General Assembly of the U.S. State of Missouri in 2022. It was signed by the Missouri Governor on July 1, 2022, and became law on August 28, 2022.
History
The Ozark Highlands are known for their limestone bluffs and caves that were used by the early inhabitants as shelters. These first settlers, Paleo-Indians known as Bluff Dwellers, inhabited the region as far back as 12,000 years ago. The first documentation of white settlers in the Ozark Highlands was around 1705. In 1799, Daniel Boone left Kentucky and settled within the northern edge of the Ozark Highlands, in what is today known as Defiance, Missouri.
The history of making spirits, primarily moonshine, is embedded in the history of the Ozark Highlands. In the 18th Century, Irish and Scottish immigrants settled in the region, bringing their distilling skills with them. In order to avoid taxation, distillers hid their production by creating and selling their liquor at night, giving birth to the name moonshine. During prohibition (1920-1933), this moonlight manufacturing actually increased and distilling became a part of the Ozarks culture.
In 2022, a group of consumers and distillers came together to discuss how to codify Ozark Highlands spirits in Missouri law. Today, more than half of the 51 distilleries in Missouri are located in the Ozark Highlands.
Geology & Topography
The Ozark Highlands is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in four U.S. states. Most of the region is within Missouri, with a part in Arkansas and small sections in Oklahoma and Kansas. It is the largest subdivision of the region known as the Ozark Mountains, less rugged in comparison to the Boston Mountains in Arkansas, the highest part of the Ozarks. The Ozarks cover a significant portion of northern Arkansas and most of the southern half of Missouri, extending from Interstate 40 in central Arkansas to Interstate 70 in central Missouri.
The Ozark Highlands ecoregion has been subdivided into eleven Level IV ecoregions, seven of which lie completely within Missouri.
The Ozarks cover nearly , making it the most extensive highland region between the Appalachians and Rockies. Together with the Ouachita Mountains, the area is known as the U.S. Interior Highlands. It is one of nine true highland regions in the world which are distinct for their soils mineral composition and limestone base.
Legislation
The Ozark Highlands Spirits legislation was first introduced in the Missouri House as HB 2621 on February 1, 2022. The House hearing took place on March 21 and was passed by the House Committee on General Laws on March 31, 2022.
During the final days of session in 2022, the "Ozark Highlands Spirits" language was included as a Senate amendment to HB 1738 sponsored by Representative Shamed Dogan. The legislation was passed by the Missouri Senate on May 11, 2022, and was passed by the Missouri House on May 13, 2022, the final day of the 2022 session. It was delivered to Missouri Governor Mike Parson on May 18 and was signed by the Governor on July 1.
The law came into effect on August 28, 2022, and is listed as Missouri Revised Statutes 311.028. The region described as the Ozark Highlands for the purposes of this legislation was drafted by the Missouri Department of Natural Resources, as required by the language of the legislation.
Requirements
Under the new Missouri law, the following requirements must be followed for a distiller to label their spirit as "Ozark Highlands" and sell it in Missouri.
Produced and bottled in the Ozark Highlands
Aged product must be aged in barrels manufactured in Missouri
Whiskey must be aged for a minimum of 4 years
Uses chemical-free water from the Ozark Highlands
Certification
Under Missouri law, any distiller wishing to produce Ozark Highlands Spirits and label them as such for sale in Missouri must have each product initially certified by the Ozark Highland Distillers Guild. The Guild is a non-profit, volunteer-run, 501(c)(3) organization.
References
External links
Ozark Highland Distillers Guild
Distilleries in Missouri
Ozarks
Economy of Missouri
Agriculture in Missouri
Distilled drinks
Highlands | Ozark Highlands Spirits | [
"Chemistry"
] | 885 | [
"Distillation",
"Distilled drinks"
] |
78,539,092 | https://en.wikipedia.org/wiki/Wood%20Science%20and%20Technology | Wood Science and Technology is a bimonthly peer-reviewed scientific journal covering all aspects of wood science and technology. It is published by Springer Nature and the editors are Klaus Richter and Jan-Willem van de Kuilen, both of the Technical University of Munich.
The journal was established in 1967 and since then, it is the official journal of the International Academy of Wood Science.
Abstracting and indexing
The journal is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2023 impact factor of 3.1.
References
External links
English-language journals
Wood science journals
Springer Science+Business Media academic journals | Wood Science and Technology | [
"Materials_science"
] | 129 | [
"Wood science journals",
"Materials science journals"
] |
78,539,126 | https://en.wikipedia.org/wiki/List%20of%20most-polluted%20rivers | This list contains rivers and other streams that have been regarded, currently or historically, as among the most polluted in the world due to their quantity of pollution, the severity of different components of the stream's pollution, its impact on the local population, or a combination of all factors.
Africa
Asia
Europe
North America
Oceania
South America
Historically polluted rivers
See also
List of most-polluted cities by particulate matter concentration
References
Pollutants
Water pollution
Pollution-related lists | List of most-polluted rivers | [
"Chemistry",
"Environmental_science"
] | 96 | [
"Water pollution"
] |
78,541,502 | https://en.wikipedia.org/wiki/Narayama%20Tile%20Kiln%20Sites | The is the collective name for several archaeological sites containing Nara period kilns located in northern Nara city in Nara Prefecture and southern Kizugawa city in Kyoto Prefecture in the Kansai region of Japan. The site was designated a National Historic Site of Japan in 1976 with the area under protection expanded in 2010..
Overview
The Narayama kiln ruins are located in the gentle hill range at an elevation of 90 to 100 meters to the north of the site of Heijō-kyō palace, the capital of Japan in the Nara period. The hills are dotted with the remains of several kilns that fired roof tiles for the palace and temples of Heijō-kyō. roof tiles made of fired clay were introduced to Japan from Baekche during the 6th century along with Buddhism. During the 570s under the reign of Emperor Bidatsu, the king of Baekche sent six people to Japan skilled in various aspects of Buddhism, including a temple architect. Initially, tiled roofs were a sign of great wealth and prestige, and used for temple and government buildings. The material had the advantages of great strength and durability, and could also be made at locations around the country wherever clay was available.
At the the existence of six semi-underground flat kilns lined up from north-to-south has been confirmed, with the existence of two or three more flat-type kilns suspected to exist to the south of those. The one at the southern end is the best preserved, and is a flat kiln with a total length of 4.2 meters, with tahe rotisserie type structure with a flame passage with seven flame vents that separate the combustion chamber from the firing chamber. The kiln walls are made of flat tiles and clay, and the fire hole is made of stone. The firing chamber is about 0.5 meters higher than the combustion chamber and measures 1.1 meters in length and 2.3 meters in width. The roof tiles fired at this tile kiln site are mainly round tiles and flat tiles, and are the same as the roof tiles found at the Heijō-kyō Palace from the end of the Nara period. It was designated a National Historic Site in 1976. It is located on the east-facing slope of the western hill facing the Shika River in northern Nara.
Four sets of kiln remains are all located in Kizugawa. The consist of four kiln remains and several post-hole buildings. It has been confirmed as the location where the roof tiles for the temple of Hokke-ji were fired. Currently, the tile kiln site has been backfilled and is preserved, and full-size replicas of the two kiln in good condition have been made and are on display. The contains traces of four buildings and eight kilns . The has been confirmed as the location where the roof tiles for the temple of Kofuku-ji were fired. Seven kiln remains have been found. At the , a clay pit and parts of "mokko" (wooden sacks) used for transportation of roof tiles were excavated along with the remains of two kilns.
The , which has been newly designated, was discovered in 1972 and found to be a kiln that supplied tiles for the construction of the first Daigokuden-in Hall of Heijō-kyō Palace, making it an important archaeological site as the earliest operating tile kiln on Narayama. Ten kilns have been identified, including rebuilt ones, and there are differences in their structures. They are thought to have been in operation between the time when the capital was moved to Nara (710) and when it was temporarily moved to Kuni-kyo (740). The site is currently preserved in a backfilled state within a private residential area.
The Utahime Tile Kiln ruins are about a 10-minute walk from Heijoyama Station on the JR West Kansai Main Line.
See also
List of Historic Sites of Japan (Kyoto)
List of Historic Sites of Japan (Nara)
References
External links
Kizugawa City home page
Nara City home page
History of Kyoto Prefecture
Nara, Nara
History of Nara Prefecture
Kizugawa, Kyoto
Yamato Province
Yamashiro Province
Historic Sites of Japan
Japanese pottery kiln sites | Narayama Tile Kiln Sites | [
"Chemistry",
"Engineering"
] | 871 | [
"Kilns",
"Japanese pottery kiln sites"
] |
78,542,376 | https://en.wikipedia.org/wiki/TYC%201031-1262-1 | TYC 1031-1262-1 is a spectroscopic binary in the northern constellation of Hercules, near the border with Ophiuchus, approximately distant. With an apparent magnitude of 11.64, it is too faint to be seen by the naked eye, but is observable using a telescope with an aperture of or larger.
The star's variability was first detected in 2005. In 2007, it was reported as the first eclipsing binary system with a type II Cepheid component to be detected in the Milky Way. It also had the shortest period of any known Cepheid binary at that time. A follow-up study in 2013, however, argues that the pulsating component is too massive to be a type II Cepheid and thus is instead an anomalous Cepheid, an object located between classical Cepheids and type II Cepheids in the Hertzsprung-Russell diagram. A similar object, NSV 10993 (V1135 Herculis), was discovered in 2008.
Physical properties
The two components are both evolved bright giants (luminosity class II), more luminous than normal giant stars but less so than supergiants. The brighter of the pair (hereafter component "A") is the Cepheid that pulsates at a period of 4.15270 days, which is increasing at a rate of for unknown reasons. It is 64% more massive than the Sun but has ballooned to 27 times the girth, radiating 764 times the luminosity of the Sun from its photosphere at an effective temperature of , corresponding to its spectral type of F8II. Its dimmer G6II companion (B) is slightly less massive than the Sun and cooler at , but has a radius 15 times larger and emits a little over 100 times the solar luminosity.
A and B revolve around each other with an orbital period of 51.2857 days at a distance of , only twice the sum of their radii. As a result of this close proximity, the pulsation and evolution of A has been affected. Furthermore, A fills nearly 85% of its Roche lobe, while B occupies 61%, meaning that a loss or transfer of mass has likely occurred from A. The amplitude of the brightness changes caused by one star eclipsing the other is relatively small, which implies that the two stars only partially eclipse each other.
The star is a member of the thick disk population, located from the Galactic plane.
Nearby objects
Follow-up observations on the star in 2008 revealed nine new variable stars in the immediate vicinity, including seven eclipsing binaries, one RR Lyrae variable, and one long-period, irregular or semiregular variable star.
See also
V1334 Cygni: a binary system containing a classical Cepheid variable.
Footnotes
References
F-type bright giants
G-type bright giants
Cepheid variables
Binary stars
Eclipsing binaries
Hercules (constellation)
J18261150+1212349 | TYC 1031-1262-1 | [
"Astronomy"
] | 638 | [
"Hercules (constellation)",
"Constellations"
] |
78,542,881 | https://en.wikipedia.org/wiki/Breakfast%20cup | The breakfast cup is a culinary measurement unit in the United Kingdom. It is named after a cup for drinking tea or coffee while eating breakfast. 1 breakfast cup is 8 British imperial fluid ounces.
Five British culinary measurement units are related to the breakfast cup: the tumbler (10 British imperial fluid ounces), the cup (6 British imperial fluid ounces), the teacup (5 British imperial fluid ounces), the coffee cup (2 British imperial fluid ounces), and the wine glass (2 British imperial fluid ounces).
All six units are the traditional British equivalents of the US customary cup and the metric cup, used in situations where a US cook would use the US customary cup and a cook using metric units the metric cup. The breakfast cup is the most similar in size to the US customary cup and the metric cup. Which of these six units is used depends on the quantity or volume of the ingredient: there is division of labour between these six units, like the tablespoon and the teaspoon. British cookery books and recipes, especially those from the days before the UK's partial metrication, commonly use two or more of these units simultaneously: for example, the same recipe may call for a ‘tumblerful’ of one ingredient and a ‘wineglassful’ of another one; or a ‘breakfastcupful’ or ‘cupful’ of one ingredient, a ‘teacupful’ of a second one, and a ‘coffeecupful’ of a third one. Unlike the US customary cup and the metric cup, a tumbler, a breakfast cup, a cup, a teacup, a coffee cup, and a wine glass are not measuring cups: they are simply everyday drinking vessels commonly found in British households and typically having the volumes listed above; due to long‑term and widespread use, they have been transformed into measurement units for cooking. There is no British imperial unit–based culinary measuring cup.
See also
Tumbler (glass)#Culinary measurement unit
Cup (unit)#British cup
Teacup (unit)
Coffee cup (unit)
Wine glass#Capacity measure
Cooking weights and measures
References
Measurement
Units of volume
Imperial units
Cooking weights and measures | Breakfast cup | [
"Physics",
"Mathematics"
] | 447 | [
"Units of volume",
"Physical quantities",
"Quantity",
"Measurement",
"Size",
"Units of measurement"
] |
78,543,490 | https://en.wikipedia.org/wiki/Cloud-init | cloud-init is a software tool developed by Canonical. It is used for doing the initial setup of virtual machines in cloud computing.
References
External links
Canonical (company) | Cloud-init | [
"Technology"
] | 36 | [
"Computing stubs",
"Software stubs"
] |
78,543,972 | https://en.wikipedia.org/wiki/Data%20clean%20room | The data clean room (DCR) is a secure, intermediary, cloud service used among companies to mutually agree on sharing and collaborating on sensitive first-party data, which is data that is collected directly from customers and consumers. Otherwise, organizations would use anonymized and obfuscated data to help preserve sensitive first-party data, such as personal identifiable information (PII). With organizations using other organizations' first-party data (third-party data) through DCRs, some say "third-party data has now become a first-class citizen in the information ecosystem".
Early data clean rooms started as data-sharing products within walled gardens, including Google's Ads Data Hub. And in 2018, this product was the only way to use Google ad data in Europe due to the General Data Protection Regulation (GDPR).
On July 5, 2023, IAB Tech Lab, a non-profit consortium that develops open technical standards for the ad-supported digital economy, released a set of common principles and operating recommendations on using DCRs.
Motivations
The creation of DCRs was needed after the deprecation of third-party cookie data with Apple's AppTrackingTransparent (ATT) framework. In 2023, IAB Tech Lab released the Open Private Join and Activation (OPJA) specification to help with clean room interoperability among clean room providers.
The demand for data clean rooms has also increased because of the Europe's GDPR law, potential fears from data breaches such as the Facebook–Cambridge Analytica data scandal, and how some advertisers don't know the data they are purchasing.
Examples
In 2019, The Hershey Company pitched the idea of a data clean room to retailers to help "get data needed to see whether its ads encourage people to buy its chocolate bars." The data clean room would allow retailers to store their loyalty card data along with ad exposure data. However, retailers resisted the idea, instead wanting the data to be in a closed platform.
In 2023, Pinterest announced that it will be using a data clean room solution from LiveRamp with Albertsons in their efforts to make Pinterest into an ecommerce platform.
Colt Technology Services has a travel platform that integrates with third party data so that employees are able to see emissions data and help them decide on choices for more sustainable travel.
In 2022, Acrisure bought the naming rights to the NFL stadium of the Pittsburgh Steelers. Hypothetically, if Acrisure wants to measure the sponsorship value of renaming the stadium, they could partner with Ticketmaster or Kraft Heinz to measure whether fans would support the name change.
Benefits
Using DCRs allow organizations to collaborate with other organizations and their data in hopes to deliver "new business opportunities and enhanced customer experiences" and is possibly "changing the way organizations collaborate, analyse and derive insights from data, enabling them to unlock new opportunities for growth and success". This data collaboration is also done where participants in the exchange are unable to see each other's raw data.
Challenges
Some key challenges for using data clean rooms include:
Agreeing on the scope of data shared
Governance and monitoring
Finding partners to agree on a shared clean room
Data clean rooms not completely solving privacy and data sharing issues
Technical challenges of integrating the data exchange with the rest of an organization's software stack
Privacy conerns
According to the Federal Trade Commission (FTC), DCRs do not necessarily mean these solutions are private and thus could lead to privacy washing. Privacy washing occurs when a company claims to prioritize data protections for its customers' data, but actually fails to implement best practices for securing the data. In other words, DCRs may facilitate the exchange of data between untrusted parties.
Corporations who operate clean rooms argue against these privacy concerns. Matt Karasick, VP of product at LiveRamp, claims that when DCRs are implemented properly, privacy policies are adhered to. He also emphasizes that when using DCR automated data protections, no consumer data is shared using clean rooms. Vlad Stesin, co-founder and chief strategy officer at a DCR company Optable, also comments that DCRs "need to be part of a broader approach to data collaboration" in order to both adhere to privacy needs and create business value.
More criticisms of DCRs include more accurately describing them as "secure" rather than "private" due to data clean rooms being owned by data companies that have their own identity graph data to connect to.
Companies
A list of some companies that operate and offer data clean room solutions include:
InfoSum
Optable
Google's Ads Data Hub
Amazon AWS' Amazon Marketing Cloud
Roku, Inc.
Paramount Pictures
The Walt Disney Company
NBCUniversal
With the rise of data clean rooms, there was a consolidation of companies offering data clean rooms. This consolidation meant eliminating friction of using multiple venders, valuing ease of use over flexible pricing, and questionable interoperability among service providers.
A list of data clean room acquisitions:
Habu (acquired by LiveRamp in 2023)
Samooha (acquired by Snowflake in 2023)
See also
Walled garden (technology)
Confidential computing
Privacy-enhancing technologies
Differential privacy
Information privacy
References
Further reading
Data Clean Rooms - Guidance and Recommended Practices Version 1.0 - IAB Tech Lab (Released July 5, 2023)
Open Private Join and Activation (OPJA) specification (Released February 14, 2024)
Data Clean Rooms: Everything You Need to Know - LiveRamp (Released Oct 5, 2022)
Data security
Information sensitivity
As a service | Data clean room | [
"Engineering"
] | 1,134 | [
"Cybersecurity engineering",
"Data security"
] |
78,546,150 | https://en.wikipedia.org/wiki/Chaetomorpha%20coliformis | Chaetomorpha coliformis, or sea emerald, is a species of seaweed.
Description
A small seaweed that grows in the intertidal zone, with glassy or clear round bladders that give the impression of strings of emeralds.
Range
New Zealand.
References
Cladophoraceae
Flora of New Zealand | Chaetomorpha coliformis | [
"Biology"
] | 67 | [
"Algae stubs",
"Algae"
] |
78,549,514 | https://en.wikipedia.org/wiki/NGC%201155 | NGC 1155 is a lenticular galaxy located in the constellation Eridanus. It was discovered by Francis Leavenworth in 1886. The galaxy is classified as type S0 and has an apparent magnitude of 13.4.
Observation
NGC 1155 can be observed in the southern sky, located at a right ascension of 02h 58m 13.0s and a declination of −10° 21′ 01″. It is part of the Eridanus constellation and is visible with moderate-sized telescopes due to its magnitude.
References
External links
SEDS - NGC 1155
In-The-Sky.org - NGC 1155
Lenticular galaxies
Eridanus (constellation)
1155 | NGC 1155 | [
"Astronomy"
] | 140 | [
"Eridanus (constellation)",
"Constellations"
] |
78,549,645 | https://en.wikipedia.org/wiki/PKS%202255-282 | PKS 2255-282 is a blazar located in the constellation of Piscis Austrinus. This is a low-polarized quasar at the redshift of 0.926, first discovered in 1975 by astronomers via a spectroscopic observation. The radio spectrum of this source appears as flat, making it as a flat-spectrum quasar but also a Gigahertz Peaked Spectrum source (GPS) with turnover frequency between 22 and 37 GHz.
Description
PKS 2255-282 is found variable on the electromagnetic spectrum. It is a source of gamma ray activity. Furthermore, it underwent a powerful millimeter wave outburst detected in 1997. During April 1997, its 90 GHz flux density exceeded 8 Jansky (Jy), which was twice the value compared to the prior observation 11 months prior to the outburst. At the end June 1997, the 90 GHz flux reached 10.1 Jy making PKS 2255-282 one of the fewer sources with high detections above 10 Jy.
In December 1997, PKS 2255-282 showed a gamma ray flare which lasted for a period of 2 weeks. During the observations, it remained in a bright state with a total measured flux of (1.6 ± 0.3) x 10−6 cm−2 s−1 and a peak flux of (4.8 ± 1.1) x 10−6 cm−2 s−1, making this value higher by factor of 20, than the upper limits of its quiescent state. A gamma ray outburst was observed by the Energetic Gamma Ray Experiment Telescope mounted abroad the Compton Gamma Ray Observatory in January 1998. In September 2012, a near-infrared ray was shown to be brightening.
The radio structure in PKS 2255-282 is complex. A 5 GHz radio image of the object made via Very Long Baseline Array, shows a strong bright core component marginally resolved at 2.8 Jy and a short jet extending southwest by 5 mas. However, when shown at higher frequencies, the jet is completely omitted from radio imaging with the core only present at 4.2 and 2.7 Jy. This core is estimated to have a size of 0.2 mas with extended emission in both south and east directions.
A quasi-periodic oscillation was detected in PKS 2255–282 in October 2024 with a period of 97 days. This is possibly explained by a binary black hole system which a model shows a secondary black hole orbiting round the primary black hole before passing through an accretion disk. Quasi-periodic signals have also been detected in this object with three high states showed during 2009–2013, 2017-2021 and in 2023.
References
External links
PKS 2255-282 on SIMBAD
Blazars
Quasars
Piscis Austrinus
Active galaxies
2831543
Astronomical objects discovered in 1975 | PKS 2255-282 | [
"Astronomy"
] | 585 | [
"Piscis Austrinus",
"Constellations"
] |
78,549,648 | https://en.wikipedia.org/wiki/NGC%201154 | NGC 1154 is a barred spiral galaxy located in the constellation Eridanus. It lies approximately 200 million light-years (62.26 Mpc) away from Earth. The galaxy was discovered by the American astronomer Francis Preserved Leavenworth on December 2, 1885.
Characteristics
NGC 1154 is classified as an SB(rs)b galaxy, indicating that it is a barred spiral galaxy with a somewhat ring-like structure. It has an apparent magnitude of 13.6, making it relatively faint and observable primarily with large telescopes.
Distance and position
Distance: ~200 million light-years (62.26 Mpc)
- Right Ascension: 02h 56m 38.6s
- Declination: −10° 21′ 47″
NGC 1154's coordinates place it within the celestial sphere of the constellation Eridanus, a region known for hosting numerous galaxies.
Possible interaction with NGC 1155
NGC 1154 is in close proximity to the galaxy NGC 1155, with which it may be interacting. A faint bridge of material appears to connect the two galaxies, suggesting tidal forces may be at play.
Observation history
NGC 1154 was discovered by Francis Leavenworth in 1885 as part of his deep-sky surveys. Modern observations have been carried out by surveys such as the Pan-STARRS and Sloan Digital Sky Survey (SDSS).
Supernova
One supernova has been observed in NGC 1154: SN2011jp (type II-P, mag. 15.5) was discovered by Greg Bock on 27 December 2011.
References
External links
SIMBAD Astronomical Database - NGC 1154
Wikisky - NGC 1154
- NGC 1154
Wikimedia Commons - Images of NGC 1154
Eridanus (constellation)
Barred spiral galaxies
1154 | NGC 1154 | [
"Astronomy"
] | 360 | [
"Eridanus (constellation)",
"Constellations"
] |
78,549,743 | https://en.wikipedia.org/wiki/Shilshila%20Acharya | Shilshila Acharya is a Nepalese environmental scientist who led successful campaigns to increase Nepal's plastic recycling. She has reduced her country's use of plastic bags and she has recovered refuse abandoned by visiting mountaineers. In 2024 she joined the BBC's list of 100 inspiring women.
Life
Acharya was born in Baglung. She surprised her family after she won a valuable Bachelor of Medicine, Bachelor of Surgery scholarship that would establish her as a surgeon. She persuaded her family that she would prefer to study environmental science even though the finances made little sense. She would need to pay for her tuition at Kathmandu University as there was no scholarship for environmental science. After graduating she went to Norway to study this time with scholarship supported by Nepal's and Norway's government. She studied biodiversity and environmental science at Tribhuvan University and the University of Bergen and she gained a master's degree.
One of her early campaigns was to suggest the a Nepalese highway should have trees planted beside it.
In 2014, she joined the Himalayan Climate Initiative as it began a move to reduce the use of plastic bags in Nepal although this was not the initial idea. Her group wanted to reduce the number of girls who were trafficked abroad. Her group joined a partnership with Bhat-Bhateni Supermarket, a large supermarket chain, to encourage the use of cloth bags instead of disposable plastic bags. The cloth bags were very popular. People bought them, but they didn't use them. The group needed to find a new way to influence people. Their new campaign's slogan was "No Thanks, I Carry My Own Bag" and this changed behaviour. It led the Nepalese government to ban the use of plastic bags in Kathmandu.
In 2018 the World Wildlife Fund in Nepal celebrated its 25th anniversary and they decided to reconstitute their Conservation awards. Acharya received one of the awards, given to individuals, because of her work as the CEO of the Himalayan Climate Initiative.
In 2019 she was involved in a campaign to reduce the large amount of refuse left in the Himalayas by visiting mountaineers. Her campaign resulted in nearly 120 tonnes of rubbish being removed.
In 2024 she was chosen to join the BBC's list of 100 inspiring women.
References
Living people
People from Baglung District
Nepalese businesspeople
Environmental scientists
Nepalese scientists
University of Bergen alumni
Tribhuvan University alumni
Year of birth missing (living people)
Nepalese women scientists | Shilshila Acharya | [
"Environmental_science"
] | 503 | [
"Environmental scientists"
] |
78,549,850 | https://en.wikipedia.org/wiki/NGC%201153 | NGC 1153 is a lenticular galaxy located in the constellation Cetus. It was discovered by Lewis Swift on December 30, 1880. The galaxy is cataloged as type S0-a, indicating a lenticular morphology, which lies between spiral and elliptical galaxies.
Characteristics
NGC 1153 has an apparent magnitude of 12.4 in the visual band and 13.3 in the blue band. Its dimensions are approximately 1.23 arcminutes by 0.85 arcminutes. The galaxy's redshift of 0.010454 indicates it is receding from the Earth at a velocity of about 3118 km/s, placing it roughly 144 million light-years (44 megaparsecs) away from the Milky Way.
Observations
NGC 1153 can be observed in the constellation Cetus, which is known for its numerous deep-sky objects. The surface brightness of NGC 1153 is relatively low, making it more challenging to observe without advanced equipment. It is part of the New General Catalogue (NGC) and has alternate designations such as PGC 11230 and UGC 2439.
References
External links
NGC 1153 on SIMBAD
Lenticular galaxies
Cetus
1153 | NGC 1153 | [
"Astronomy"
] | 242 | [
"Cetus",
"Constellations"
] |
78,550,245 | https://en.wikipedia.org/wiki/Prostitute%27s%20caution | A prostitute's caution is a type of police caution in the United Kingdom. They are issued to those the police consider to be "loitering and soliciting". Unlike other forms of police cautions, they are not regulated by statute law, but are based on an agreement between British police chiefs.
Description
Prostitute's cautions can be used as police as evidence of "persistence" for the criminal offence of persistently loitering or soliciting defined in Section1(1) of the Street Offences Act 1959, which states that "the conduct is persistent if it takes place on two or more occasions in any period of three months".
There is no need for a criminal offence to be committed for one to be issued, nor is there any need for the person they are issued to admit to an offence.
Unlike an ordinary police cautions, they do not expire until the person they are issued to reaches the age of 100, making them effectively life-long. Having a prostitute's caution can prevent its recipient (usually a woman) from taking on other forms of work that require vetting, such as work in the care sector.
References
See also
Common prostitute
Prostitution in the United Kingdom
Law of the United Kingdom
Law enforcement in the United Kingdom | Prostitute's caution | [
"Biology"
] | 257 | [
"Behavior",
"Sexuality stubs",
"Sexuality"
] |
78,552,976 | https://en.wikipedia.org/wiki/Rosa%20V%C3%A1squez%20Espinoza | Rosa Vásquez Espinoza is a Peruvian chemical biologist and conservationist who founded Amazon Research Internacional, an organization focused on biodiversity research and conservation in the Amazon rainforest. Her work integrates traditional ecological knowledge with modern science, emphasizing sustainable practices and community collaboration.
Early life and education
Rosa Vásquez Espinoza was born in Peru, with family roots in both the Andes and the Amazon rainforest. Her upbringing was influenced by her grandmother, a traditional healer in the Andes who relied on medicinal plants to create remedies. This early exposure to natural medicine and cultural traditions inspired Vásquez Espinoza and later influenced her scientific career.
Vásquez Espinoza attended school in Lima, but spent her summers in the Amazon and Andes, experiencing rural life and interacting with the local biodiversity. She received a scholarship to attend Tennessee Tech, where she earned a B.S. in biology and chemistry in 2015. She completed a Ph.D. in chemical biology from the University of Michigan.
From 2016 to 2022, Vásquez Espinoza worked in the life science laboratory at the University of Michigan under David H. Sherman, including as a postdoctoral researcher. In 2019, she joined a scientific expedition to the shanay-timpishka to study its unique ecosystem. During the trip, she collected samples of water, sediment, and microbes, documenting environmental conditions such as temperature and sunlight to better understand the microorganisms thriving in the river’s extreme heat.
Career
Vásquez Espinoza is a chemical biologist whose work centers on exploring biodiversity in extreme ecosystems, particularly the Amazon rainforest. Her research focuses on microorganisms and stingless bees, examining their ecological roles and potential applications in medicine and conservation. She founded Amazon Research Internacional, an institute dedicated to collaborative research and the integration of traditional knowledge with modern science.
Vásquez Espinoza's projects include mapping stingless bee populations and studying their honey's chemical properties, which have shown potential medicinal benefits. She collaborates with Indigenous communities, incorporating their knowledge and practices into conservation strategies. Her partnerships extend to academic institutions and policymakers, focusing on biodiversity preservation and sustainability.
Vásquez Espinoza has participated in initiatives to address the impacts of deforestation, climate change, and environmental pollutants on the Amazon's ecosystem. She has contributed to legislative efforts advocating for the protection of stingless bees in Peru, aiming to enhance conservation and support local economies. In 2024, she was listed on BBC 100 Women.
References
External links
Living people
Place of birth missing (living people)
Year of birth missing (living people)
Date of birth missing (living people)
Scientists from Lima
Peruvian women scientists
Conservationists
Peruvian women environmentalists
21st-century Peruvian women
21st-century Peruvian scientists
21st-century biologists
Chemical biologists
Women biologists
Tennessee Technological University alumni
University of Michigan alumni | Rosa Vásquez Espinoza | [
"Chemistry"
] | 578 | [
"Chemical biologists"
] |
78,553,332 | https://en.wikipedia.org/wiki/Stibinidene | Stibinidenes are a class of organoantimony compounds in which the antimony center exhibits a formal oxidation state of +1. The parent stibinidenes have the formula R–Sb, with the antimony center possessing two lone pairs of electrons and a vacant 5p orbital (Figure 1). Reflecting their unusual low coordination number]] (i.e., 1) at [antimony]], stibinidines cannot be isolated. Instead, their oligomers or their adducts are often robust.
Synthesis
Attempted synthesis of stibinidenes, like carbenes, gives cyclic oligomeric forms. 6-, 5-, 4-, and 3-membered rings have been characterized. They are orange solids. These species exist in equilibrium:
Distibinidenes, in principle, can be produced by reduction of the corresponding dichlorides. The following idealized equations apply:.
2,4,6-Tris[bis(trimethylsilyl)methyl]phenyl, 2,6-bis-[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl, and various m-terphenyl ligands, exist as dimers with the formula RSb=SbR.
When R is bulky, the product "RSb" is obtained as ring with Sb-Sb bonds. Larger substituents give smaller rings, otherwise 5- and 6-membered rings form. In some cases, a dimer with an Sb=Sb bond is isolated.
Base-stabilized stibinidene
Monomeric stibinidenes were first obtained by Dostál reported a Sb(I) center stabilized by an N,C,N-pincer ligand. The ligand employed was L = 2,6-bis[N-(2',6'-dimethylphenyl)ketimino]phenyl. The synthesis of this complex was achieved by reducing LSb(III)Cl2 with two equivalents of t K[B(iBu)3H], resulting in the formation of isolable crystals of the stable monomeric stibinidene [C6H3-2,6-(C(Me)=N-2',6'-Me2C6H3)2]Sb via dihydrogen elimination (Scheme 2). In this system, coordination from the nitrogen centers provides thermodynamic stabilization to the Sb(I) center by delocalizing electron density, while the bulky N,C,N ligand introduces significant steric hindrance, which kinetically stabilizes the monomeric stibinidene by preventing dimerization or further reactions. Subsequently, other N,C,N-coordinating ligands were developed to produce stibinidenes, such as ArSb (where Ar = C6H3-2,6-(CH=NtBu)2 & Ar = C6H3-2,6-(CH=NDipp)2) which gained prominence in studies on stibinidene reactivity.
Carbene stabilized stibinidene
Diamidocarbene (DAC) stabilize monomeric stibinidenes. The synthesis involved the reaction of phenylantimony dichloride, stabilized by a DAC, with magnesium powder in THF (Scheme 3). This process yielded stable, isolable, fluorescent red crystals of the carbene-stabilized stibinidene, (DAC)Sb-Ph. Despite the exocyclic Sb(I) center being exposed, the compound exists as a monomer, with its stability attributed to the strong backbonding between the DAC and the antimony center. The steric bulk of the mesityl group in the carbene further contributes to the compound's kinetic stability. Density functional theory (DFT) calculations revealed that the stability of the compound arises from partial double bond character between the carbene carbon and the Sb(I) center. This is attributed to backbonding from the antimony center into the vacant p orbital of the carbene. Chloro-substituted stibinidenes have been trapped using a cyclic alkyl(amino)carbene (CAAC) ligand. The synthesis involved reduction of CAAC-coordinated SbCl3 with KC8. Subsequently, the phosphine stabilized stibinidene (o-PPh2)C6H4(Ar*)Ge(Cl)Sb (E, where Ar* = 2,6-Trip2C6H3), was reported.
Reactivity
Theoretically, singlet stibinidenes are ambiphilic due to the presence of both empty and filled 5p orbitals, which respectively confer Lewis acidic and Lewis basic character. However, N,C,N-pincer-coordinated stibinidenes exhibit diminished Lewis acidity because of nN → p*Sb donor-acceptor interactions. Despite this reduction in Lewis acidity, Dostál’s stibinidene remains widely utilized in reactivity studies. In contrast, carbene-stabilized stibinidenes show significantly reduced reactivity as strong electron donation from the carbene ligand diminishes the Lewis acidic nature, while strong back-donation from the Sb center to the carbene weakens their Lewis basicity. Due to their ambiphilic nature, Dostál’s stibinidenes are capable of activating small molecules, like disulfides, through oxidative addition. This reactivity arises from their ability to donate electron density to the LUMO of small molecules while simultaneously accepting electron density into the vacant 5p orbital. Dostál's N,C,N-coordinated stibinidene ArSb (where Ar = C6H3-2,6-(CH=NtBu)2) has been reported to act as a catalyst in the hydroboration of disulfides (Scheme 5). This reactivity exploits the ability of the stibinidene to reversibly interconvert between Sb(I) and Sb(III) oxidation states under the reaction conditions. The catalytic cycle involves the oxidative addition of disulfides to the Sb(I) center, followed by reductive elimination to regenerate the active species, enabling efficient hydroboration. As of 2024, this is the only reported example of catalysis involving stibinidene, demonstrating its potential in organometallic catalysis. Notably, triplet stibinidenes exhibit a distinct mode of reactivity. Acting as diradicals, they can react with small molecules such as alkynes and butadienes, forming antimony-substituted heterocycles, including three-membered and five-membered rings respectively (Scheme 4).
Small molecule activation and catalysis
The stibinidene ArSb (where Ar = C6H3-2,6-(CH=NtBu)2) oxidatively adds E2Ph2 (E = S, Se), resulting giving ArSb(EPh)2 (Scheme 5). catalytic cycle using this oxidized product (Scheme 5). The Sb(III)dithiolate reacts with pinacolborane at 70 °C to produce ArSb(SR)(H) and the S-borylated thiophenol derivatives. This process can be made catalytic in the presence of an α,β-unsaturated carbonyl to facilitate Michael addition reactions.
Fluind ligand and reported by Cornella et al., exhibits remarkable small molecule activation. Under a 1.2 bar atmosphere of H2 or ethylene at 60°C, the distibene was converted into the corresponding antimony dihydride or stibacyclopropane, respectively, via a transient stibinidene intermediate. NMR studies confirmed that this transient stibinidene adopts a triplet electronic configuration, allowing it to activate small molecules in a diradical fashion. Similarly, the reactivity of an isolated triplet stibinidene was observed. Acting as diradicals, this stibinidene react with small molecules such as 2,3-dimethyl-1,3-butadiene and 4-tetrabutylphenylacetylene, leading to the formation of antimony-substituted heterocycles, including five-membered and three-membered rings.
Hetero Diels-Alder reaction with alkynes
The Dostál group demonstrated that N,C,N-pincer-coordinated stibinidenes can act as masked heterocyclic dienes. When treated with the electron-deficient alkyne dimethyl acetylenedicarboxylate (DMAD), these stibinidenes undergo a hetero Diels–Alder [4+2] cycloaddition reaction (Scheme 6). This transformation yields a CO2Me-disubstituted 1-stiba-1,4-dihydro-iminonaphthalene, effectively converting one of the pendant imine arms of the stibinidene into a nitrogen-bridged stibacyclohexadiene. In this product, the Sb(III) atom serves as a bridgehead, while the second imine arm loses coordination with the Sb(III) center. Additionally, similar cycloaddition reactions were observed between Dostal's stibinidene and other substrates, such as methyl propiolate and N-alkyl/aryl-maleimides, RN(C(O)CH)2 (R = Me, tBu, Ph). These findings highlight the reactivity of stibinidenes as dienes, expanding their utility in cycloaddition chemistry.
Transition metal-"stabilized" stibinidenes
Complexes containing one or more ligands with the formula RSb (R = halide, alkyl, chloride, aryl) are called stibinidene complexes. The terminology is debatable because these complexes do not release RSb. As ligands, stibinidenes ligand resemble carbenes to some extent. bulky N,C,N-pincer ligands, phosphine based and gallium based ligand. Based on computational studies, ⲡ-donating substituents, such as nitrogen- and phosphorus-based anionic ligands attached to the pnictogen atom, significantly stabilize the singlet ground state of stibinidenes. In this state, the molecule features one stereochemically inactive lone pair with predominantly s-character and another lone pair with predominantly p-character, accompanied by a vacant p orbital, making stibinidenes ambiphilic (Figure 1). In contrast, σ-type ligands, such as hydride and alkyl groups, favor the triplet ground state, where two unpaired electrons occupy two 5p orbitals and one lone pair resides in the 5s orbital.
One early example is , which was obtained from phenyldiiodostibane. The geometry at Sb is trigonal planar . the authors proposed the presence of Sb–Mn π-bonding. The chloro substituted stibinidene complex, [ClSb{Cr(CO)5}2] again features a three-center, four-π-electron bond across both Sb–Cr bonds. Trigonal planar stibinidene complexes of the type [ClSb{M(CO)5}2] (A, where M = Cr, Mo, W) are typically prepared via salt-elimination reactions between Na2[M2(CO)10] and SbCl3 (Scheme 1). However, these complexes are highly unstable due to the vacant p orbital on the antimony center and, in the case of M = Mo or W, cannot easily be isolated. To stabilize these complexes, they can be trapped using Lewis bases (LB), forming stable adducts with the general formula [ClSb{M(CO)5}2LB] (B) (Scheme 1). Huttner and colleagues also identified distibene complexes of the type [RSb=SbR][W(CO)5]3 as side products during stibinidene synthesis, particularly when non-donor solvents were used. This observation highlights the critical role of donor molecules in stabilizing these compounds.
Stibinidene cation
Stibinidene cations are isoelectronic with carbenes (Scheme 8). The stibinidene cation was generated by reduction of SbX3 (X = F, Cl) with KC8, in the presence of one equivalent of LiOTf, with stabilization provided by the addition of an IPr CAAC ligand. This process resulted in the formation of a CAAC-stabilized Sb(I) cation. Previously, attempts to stabilize Sb(I) cations were made using a bis(diisopropylamino)cyclopropenylidene ligand. However, the resulting species was obtained in low yield and exhibited significant instability, undergoing decomposition. Subsequently, Majumdar et al. reported the isolation of an Sb(I) cation stabilized with a diphosphine ligand. In this synthesis, SbCl3, the bis(phosphine) ligand, and trimethylsilyl trifluoromethanesulfonate were reacted in a 1:2:3 ratio at room temperature. The bis(phosphine) ligand was found to act as both a reductant and a supporting ligand. Despite the overall positive charge of the Sb(I) site, it was observed to bind metal centers, forming complexes with Au(I), Ag(I), and Cu(I). Further progress was made by Zhenbo et al., who isolated an Sb(I) cation stabilized by a bis-silylene ligand. The lone pair on the Sb(I) center in this species was shown to coordinate with Cr and Mo carbonyls. Sb(I) cations can also be generated when a diiminopyridine ligand on Sb.
Further reading
References
Organoantimony compounds | Stibinidene | [
"Chemistry"
] | 3,011 | [
"Functional groups",
"Octet-deficient functional groups"
] |
78,553,555 | https://en.wikipedia.org/wiki/Oksana%20Chubykalo-Fesenko | Oksana Chubykalo-Fesenko is a Ukrainian physicist and materials scientist whose research interests include spintronics and the dynamics and multiscale modeling of magnetic materials and magnetic particles. She works in Spain as a senior scientist at the Materials Science Institute of Madrid, a research institute of the Spanish National Research Council.
Education and career
Chubykalo-Fesenko was a student at the National University of Kharkiv (then called Kharkiv State University) where she received a master's degree in 1986 and a Ph.D. in 1990, with the dissertation Soliton scattering by inpurities in one-dimensional nonlinear systems.
She worked as a researcher at the Clarendon Laboratory of the University of Oxford, at the Complutense University of Madrid, at the University of Milan, at the University of the Basque Country, and at the IBM Almaden Research Center in California, before taking her present position at the Materials Science Institute of Madrid. She joined the institute in 2001 as a Ramon y Cajal Fellow, obtained a tenured scientist position in 2002, and has been senior scientist since 2004.
Recognition
Chubykalo-Fesenko was named to the 2025 class of IEEE Fellows, "for development of multiscale methods for modeling of thermal magnetization dynamics."
References
External links
Year of birth missing (living people)
Living people
Ukrainian emigrants to Spain
Ukrainian physicists
Ukrainian women physicists
Spanish physicists
Spanish women physicists
Materials scientists and engineers
Women materials scientists and engineers
National University of Kharkiv alumni
Fellows of the IEEE | Oksana Chubykalo-Fesenko | [
"Materials_science",
"Technology",
"Engineering"
] | 323 | [
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology",
"Materials science"
] |
78,553,678 | https://en.wikipedia.org/wiki/Christian%20Hackenberger | Christian P. R. Hackenberger (b. Osnabruck, 1976) is a German chemist. He is a professor of Chemical Biology at the Humboldt University of Berlin and heads the research unit Biomolecule Modification and Delivery at the Leibniz Research Institute for Molecular Pharmacology. He is a co-founder of the Munich-based biotech company Tubulis.
Life and education
Christian Hackenberger grew up in Damme. He attended the Gymnasium Damme, where he obtained his Abitur in 1995. After completing his civil service, he studied chemistry at the Alfred-Ludwig-Universität in Freiberg (1996–1998) and the University of Wisconsin-Madison (M.S. with Samuel H. Gellman, 1998–1999), with support from the German Academic Scholarship Foundation. He pursued his doctoral studies at the RTWH Aachen (2000–2003), where he worked under Prof. Carsten Bolm as a Kekulé Fellow from the Fonds der Chemischen Industrie. During this time, he also worked as an editorial assistant in scientific journalism for the WDR broadcast "Quarks & Co". From 2003 to 2005 he was a DAAD Postdoctoral Fellow at the Massachusetts Institute of Technology under Prof. Barbara Imperiali.
In 2005, Hackenberger founded his own research group at the Free University of Berlin in 2005 as an Emmy Noether Fellow. In 2011, he was appointed as W2 Professor of Bioorganic Chemistry at the Free University of Berlin as the first Plus 3 awardee from the Boehringer Ingelheim Foundation. In 2012, he became Leibniz-Humboldt Professor for Chemical Biology at the Leibniz Research Institute for Molecular Pharmacology and the Humboldt University of Berlin. In 2020, Hackenberger co-founded the Munich-based biotechnology company Tubulis, which specializes in developing antibody-drug conjugates. He has served as associate editor of the Royal Society of Chemistry's scientific journals Organic and Biomolecular Chemistry (2015–2023) and Chemical Science (since 2024). Hackenberger lives in Berlin, and is married to the art historian Michel Otayek.
Research
Hackenberger's research at the Leibniz Research Institute focuses on chemical strategies to functionalize proteins and antibodies using highly selective chemical reactions to generate protein-based therapeutics against cancer, Alzheimer's and viral infections. A particular focus of Hackenberger's research group is the engineering of new reactions for the modification and cellular delivery of proteins and antibodies to advance their use in biological and pharmacological research.
Awards
Hackenberger has received numerous awards for his work, including the Heinz Maier-Leibnitz Prize of the German Research Foundation (2011), the ORCHEM Prize of the German Chemical Society (2012), the Zervas Award of the European Peptide Society (2018), the Breakthrough of the Year Award in the life sciences from the Falling Walls Foundation (2020), the Astra-Zeneca Award of the Royal Society of Chemistry (2023), the Xiaoyu Hu Memorial Award of the Chinese Peptide Society (2023), and the Max Bergmann Medal (2024).
External links
The Hackenberger Group (Homepage)
The Hackenberger Group (X Profile)
BR Campus Talk: Wie kommen Medikamente im Körper sicher ans Ziel?
References
1976 births
Living people
21st-century German chemists
People from Damme
Humboldt University of Berlin
Chemical biologists
Free University of Berlin | Christian Hackenberger | [
"Chemistry"
] | 736 | [
"Chemical biologists"
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78,553,777 | https://en.wikipedia.org/wiki/Deucalion%20%28supercomputer%29 | Deucalion is a supercomputer located at the Minho Advanced Computing Center (MAAC) in Guimarães, Portugal. It was inaugurated in September 2023 and is co-funded by the EuroHPC Joint Undertaking and Portugal's Foundation for Science and Technology. It is currently the fastest supercomputer in Portugal and is ranked 257th in the TOP500 global list of supercomputers.
History
In June 2019, the European High-Performance Computing (EuroHPC) Joint Undertaking announced the building of eight supercomputers in several sites across the European Union, with the aim of equipping the European Union with a world-class supercomputing infrastructure. The Minho region in Portugal was one of the selected sites.
In February 2021, the contract for a new petascale supercomputer, named Deucalion, was signed by the EuroHPC Joint Undertaking, the Portuguese Foundation for Science and Technology, and Fujitsu. It was also announced that Deucalion would be installed in the Minho Advanced Computing Centre (MACC).
Deucalion was officially inaugurated on 6 September 2023. It entered the TOP500 global list of supercomputers in June 2024, ranked 219th in processing speed and 80th in energy efficiency.
Architecture
The Deucalion supercomputer consists of two main general-purpose compute partitions based on different processor architectures (ARMv8-A and x86) and one GPU-based compute partition. Users have access to the system through a set of front-end servers. All nodes are connected to a high-performance shared storage through an InfiniBand high-speed interconnect based on Mellanox QM8790 switches, and to an Ethernet network.
Deucalion’s largest compute partition is based on the ARMv8-A architecture and consists of 1632 Fujitsu PRIMEHPC FX700 nodes equipped with Fujitsu A64FX 2.0 GHz processors. Each node offers 16 GB of in-processor High Bandwidth Memory. The partition peaks at 5 petaFLOPS of double precision performance.
The second compute partition is based on the x86 architecture and consists of 500 ATOS Bull Sequana X440 dual processor nodes equipped with AMD EPYC Rome 7742 (2.25 GHz) processors. Each node offers 256 GB of RAM. The partition peaks at 2.3 petaFLOPS of double precision performance.
The GPU-based compute partition consists of 33 ATOS Bull Sequana E410 nodes equipped with four Nvidia A100 GPUs and two AMD Epyc Rome 7742 (2.25 GHz) processors. Each node offers 80 GB of High Bandwidth Memory per GPU and 512 GB of RAM. The partition peaks at 2.7 petaFLOPS of double precision performance.
All nodes have access to a high-performance shared storage based on the DDN EXAScaler subsystem using ES400VNX controllers. The storage offers a 10.6 PB parallel filesystem and a 430 TB NVM multi-purpose high-speed layer. An additional NetApp All Flash A220 network attached storage with 70 TB is available for user homes and spooling.
See also
Leonardo, another EuroHPC computer in Bologna, Italy
LUMI, another EuroHPC supercomputer in Kajaani, Finland
References
Petascale computers
Supercomputing in Europe | Deucalion (supercomputer) | [
"Technology"
] | 715 | [
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78,554,064 | https://en.wikipedia.org/wiki/History%20of%20the%20LED | The first Light-Emitting Diode (LED) was created in 1927 by Russian inventor Oleg Losev, and used silicon carbide as a semiconductor. However, electroluminescence as a phenomenon was discovered twenty years earlier by the English experimenter Henry Joseph Round of Marconi Labs, using the same crystal and a cat's-whisker detector. Despite having distributed his report in Soviet, German and British scientific journals, Losev's LED found no practical use for several decades, partly due to the very inefficient light-producing properties the semiconductor used.
In 1936, Georges Destriau observed that electroluminescence could be produced when zinc sulphide (ZnS) powder is suspended in an insulator and an alternating electrical field is applied to it. In his publications, Destriau often referred to luminescence as Losev-Light. Destriau worked in the laboratories of Madame Marie Curie, also an early pioneer in the field of luminescence with research on radium.
Hungarian Zoltán Bay together with György Szigeti patenting a lighting device in Hungary in 1939 based on silicon carbide, with an option on boron carbide, that emitted white, yellowish white, or greenish white depending on impurities present. Kurt Lehovec, Carl Accardo, and Edward Jamgochian explained these first LEDs in 1951 using an apparatus employing SiC crystals with a current source of a battery or a pulse generator and with a comparison to a variant, pure, crystal in 1953.
Rubin Braunstein of the Radio Corporation of America reported on infrared emission from gallium arsenide (GaAs) and other semiconductor alloys in 1955. Braunstein observed infrared emission generated by simple diode structures using gallium antimonide (GaSb), GaAs, indium phosphide (InP), and silicon-germanium (SiGe) alloys at room temperature and at 77K. In 1957, Braunstein further demonstrated that the rudimentary devices could be used for non-radio communication across a short distance. As noted by Kroemer Braunstein "…had set up a simple optical communications link: Music emerging from a record player was used via suitable electronics to modulate the forward current of a GaAs diode. The emitted light was detected by a PbS diode some distance away. This signal was fed into an audio amplifier and played back by a loudspeaker. Intercepting the beam stopped the music. We had a great deal of fun playing with this setup."
In September 1961, while working at Texas Instruments in Dallas, Texas, James R. Biard and Gary Pittman discovered near-infrared (900 nm) light emission from a tunnel diode they had constructed on a GaAs substrate. By October 1961, they had demonstrated efficient light emission and signal coupling between a GaAs p-n junction light emitter and an electrically isolated semiconductor photodetector. On August 8, 1962, Biard and Pittman filed a patent titled "Semiconductor Radiant Diode" based on their findings, which described a zinc-diffused p–n junction LED with a spaced cathode contact to allow for efficient emission of infrared light under forward bias.
After establishing the priority of their work based on engineering notebooks predating submissions from G.E. Labs, RCA Research Labs, IBM Research Labs, Bell Labs, and Lincoln Lab at MIT, the U.S. patent office issued the two inventors the patent for the GaAs infrared light-emitting diode (U.S. Patent US3293513), the first practical LED. Immediately after filing the patent, Texas Instruments (TI) began a project to manufacture infrared diodes. In October 1962, TI announced the first commercial LED product (the SNX-100), which employed a pure GaAs crystal to emit an 890 nm light output. In October 1963, TI announced the first commercial hemispherical LED, the SNX-110.
In the 1960s, several laboratories focused on LEDs that would emit visible light. A particularly important device was demonstrated by Nick Holonyak on October 9, 1962, while he was working for General Electric in Syracuse, New York. The device used the semiconducting alloy gallium phosphide arsenide (GaAsP). It was the first semiconductor laser to emit visible light, albeit at low temperatures. At room temperature it still functioned as a red light-emitting diode. GaAsP was the basis for the first wave of commercial LEDs emitting visible light. It was mass produced by the Monsanto and Hewlett-Packard companies and used widely for displays in calculators and wrist watches.
M. George Craford, a former graduate student of Holonyak, invented the first yellow LED and improved the brightness of red and red-orange LEDs by a factor of ten in 1972. In 1976, T. P. Pearsall designed the first high-brightness, high-efficiency LEDs for optical fiber telecommunications by inventing new semiconductor materials specifically adapted to optical fiber transmission wavelengths.
Initial commercial development
Until 1968, visible and infrared LEDs were extremely costly, on the order of US$200 per unit, and so had little practical use. The first commercial visible-wavelength LEDs used GaAsP semiconductors and were commonly used as replacements for incandescent and neon indicator lamps, and in seven-segment displays, first in expensive equipment such as laboratory and electronics test equipment, then later in such appliances as calculators, TVs, radios, telephones, as well as watches.
The Hewlett-Packard company (HP) was engaged in research and development (R&D) on practical LEDs between 1962 and 1968, by a research team under Howard C. Borden, Gerald P. Pighini at HP Associates and HP Labs. During this time HP collaborated with Monsanto Company on developing the first usable LED products. The first usable LED products were HP's LED display and Monsanto's LED indicator lamp, both launched in 1968.
Monsanto was the first organization to mass-produce visible LEDs, using Gallium arsenide phosphide (GaAsP) in 1968 to produce red LEDs suitable for indicators. Monsanto had previously offered to supply HP with GaAsP, but HP decided to grow its own GaAsP. In February 1969, Hewlett-Packard introduced the HP Model 5082-7000 Numeric Indicator, the first LED device to use integrated circuit (integrated LED circuit) technology. It was the first intelligent LED display, and was a revolution in digital display technology, replacing the Nixie tube and becoming the basis for later LED displays.
In the 1970s, commercially successful LED devices at less than five cents each were produced by Fairchild Optoelectronics. These devices employed compound semiconductor chips fabricated with the planar process (developed by Jean Hoerni, ). The combination of planar processing for chip fabrication and innovative packaging methods enabled the team at Fairchild led by optoelectronics pioneer Thomas Brandt to achieve the needed cost reductions. LED producers have continued to use these methods as of about 2009.
The early red LEDs were bright enough for use as indicators, as the light output was not enough to illuminate an area. Readouts in calculators were so small that plastic lenses were built over each digit to make them legible. Later, other colors became widely available and appeared in appliances and equipment.
Early LEDs were packaged in metal cases similar to those of transistors, with a glass window or lens to let the light out. Modern indicator LEDs are packed in transparent molded plastic cases, tubular or rectangular in shape, and often tinted to match the device color. Infrared devices may be dyed, to block visible light. More complex packages have been adapted for efficient heat dissipation in high-power LEDs. Surface-mounted LEDs further reduce the package size. LEDs intended for use with fiber optics cables may be provided with an optical connector.
Blue LED
The first blue-violet LED, using magnesium-doped gallium nitride was made at Stanford University in 1972 by Herb Maruska and Wally Rhines, doctoral students in materials science and engineering. At the time Maruska was on leave from RCA Laboratories, where he collaborated with Jacques Pankove on related work. In 1971, the year after Maruska left for Stanford, his RCA colleagues Pankove and Ed Miller demonstrated the first blue electroluminescence from zinc-doped gallium nitride, though the subsequent device Pankove and Miller built, the first actual gallium nitride light-emitting diode, emitted green light.
In 1974 the U.S. Patent Office awarded Maruska, Rhines, and Stanford professor David Stevenson a patent for their work in 1972 (U.S. Patent US3819974 A). Today, magnesium-doping of gallium nitride remains the basis for all commercial blue LEDs and laser diodes. In the early 1970s, these devices were too dim for practical use, and research into gallium nitride devices slowed.
In August 1989, Cree introduced the first commercially available blue LED, based on the indirect bandgap semiconductor, silicon carbide (SiC). SiC LEDs had very low efficiency, no more than about 0.03%, but did emit in the blue portion of the visible light spectrum.
In the late 1980s, key breakthroughs in GaN epitaxial growth and p-type doping ushered in the modern era of GaN-based optoelectronic devices. Building upon this foundation, Theodore Moustakas at Boston University patented a method for producing high-brightness blue LEDs using a new two-step process in 1991. In 2015, a US court ruled that three Taiwanese companies had infringed Moustakas's prior patent, and ordered them to pay licensing fees of not less than US$13 million.
Two years later, in 1993, high-brightness blue LEDs were demonstrated by Shuji Nakamura of Nichia Corporation using a gallium nitride (GaN) growth process. These LEDs had efficiencies of 10%. In parallel, Isamu Akasaki and Hiroshi Amano of Nagoya University were working on developing the important GaN deposition on sapphire substrates and the demonstration of p-type doping of GaN. This new development revolutionized LED lighting, making high-power blue light sources practical, leading to the development of technologies like Blu-ray.
Nakamura was awarded the 2006 Millennium Technology Prize for his invention. Nakamura, Hiroshi Amano, and Isamu Akasaki were awarded the Nobel Prize in Physics in 2014 for "the invention of efficient blue light-emitting diodes, which has enabled bright and energy-saving white light sources."
In 1995, Alberto Barbieri at the Cardiff University Laboratory (GB) investigated the efficiency and reliability of high-brightness LEDs and demonstrated a "transparent contact" LED using indium tin oxide (ITO) on (AlGaInP/GaAs).
In 2001 and 2002, processes for growing gallium nitride (GaN) LEDs on silicon were successfully demonstrated. In January 2012, Osram demonstrated high-power InGaN LEDs grown on silicon substrates commercially, and GaN-on-silicon LEDs are in production at Plessey Semiconductors. As of 2017, some manufacturers are using SiC as the substrate for LED production, but sapphire is more common, as it has the most similar properties to that of gallium nitride, reducing the need for patterning the sapphire wafer (patterned wafers are known as epi wafers). Samsung, the University of Cambridge, and Toshiba are performing research into GaN on Si LEDs.
Toshiba has stopped research, possibly due to low yields. Some opt for epitaxy, which is difficult on silicon, while others, like the University of Cambridge, choose a multi-layer structure, in order to reduce (crystal) lattice mismatch and different thermal expansion ratios, to avoid cracking of the LED chip at high temperatures (e.g. during manufacturing), reduce heat generation and increase luminous efficiency. Sapphire substrate patterning can be carried out with nanoimprint lithography.
GaN-on-Si is difficult but desirable since it takes advantage of existing semiconductor manufacturing infrastructure. It allows for the wafer-level packaging of LED dies resulting in extremely small LED packages.
GaN is often deposited using metalorganic vapour-phase epitaxy (MOCVD), and it also uses lift-off.
White LEDs and the illumination breakthrough
Even though white light can be created using individual red, green and blue LEDs, this results in poor color rendering, since only three narrow bands of wavelengths of light are being emitted. The attainment of high efficiency blue LEDs was quickly followed by the development of the first white LED. In this device a :Ce (known as "YAG" or Ce:YAG phosphor) cerium-doped phosphor coating produces yellow light through fluorescence. The combination of that yellow with remaining blue light appears white to the eye. Using different phosphors produces green and red light through fluorescence. The resulting mixture of red, green and blue is perceived as white light, with improved color rendering compared to wavelengths from the blue LED/YAG phosphor combination.
The first white LEDs were expensive and inefficient. The light output then increased exponentially. The latest research and development has been propagated by Japanese manufacturers such as Panasonic and Nichia, and by Korean and Chinese manufacturers such as Samsung, Solstice, Kingsun, Hoyol and others. This trend in increased output has been called Haitz's law after Roland Haitz.
Light output and efficiency of blue and near-ultraviolet LEDs rose and the cost of reliable devices fell. This led to relatively high-power white-light LEDs for illumination, which are replacing incandescent and fluorescent lighting.
Experimental white LEDs were demonstrated in 2014 to produce 303 lumens per watt of electricity (lm/W); some can last up to 100,000 hours. Commercially available LEDs have an efficiency of up to 223 lm/W as of 2018. A previous record of 135 lm/W was achieved by Nichia in 2010. Compared to incandescent bulbs, this is a huge increase in electrical efficiency, and even though LEDs are more expensive to purchase, overall lifetime cost is significantly cheaper than that of incandescent bulbs.
The LED chip is encapsulated inside a small, plastic, white mold although sometimes an LED package can incorporate a reflector. It can be encapsulated using resin (polyurethane-based), silicone, or epoxy containing (powdered) Cerium-doped YAG phosphor particles. The viscosity of phosphor-silicon mixtures must be carefully controlled. After application of a phosphor-silicon mixture on the LED using techniques such as jet dispensing, and allowing the solvents to evaporate, the LEDs are often tested, and placed on tapes for SMT placement equipment for use in LED light bulb production. Some "remote phosphor" LED light bulbs use a single plastic cover with YAG phosphor for one or several blue LEDs, instead of using phosphor coatings on single-chip white LEDs. Ce:YAG phosphors and epoxy in LEDs can degrade with use, and is more apparent with higher concentrations of Ce:YAG in phosphor-silicone mixtures, because the Ce:YAG decomposes with use.
The output of LEDs can shift to yellow over time due to degradation of the silicone. There are several variants of Ce:YAG, and manufacturers in many cases do not reveal the exact composition of their Ce:YAG offerings. Several other phosphors are available for phosphor-converted LEDs to produce several colors such as red, which uses nitrosilicate phosphors, and many other kinds of phosphor materials exist for LEDs such as phosphors based on oxides, oxynitrides, oxyhalides, halides, nitrides, sulfides, quantum dots, and inorganic-organic hybrid semiconductors. A single LED can have several phosphors at the same time. Some LEDs use phosphors made of glass-ceramic or composite phosphor/glass materials. Alternatively, the LED chips themselves can be coated with a thin coating of phosphor-containing material, called a conformal coating.
The temperature of the phosphor during operation and how it is applied limits the size of an LED die. Wafer-level packaged white LEDs allow for extremely small LEDs.
Polychromatic
In 2024, QPixel introduced as polychromatic LED that could replace the 3-subpixel model for digital displays. The technology uses a gallium nitride semiconductor that emits light of different frequencies modulated by voltage changes. A prototype display achieved a resolution of 6,800 PPI or 3k x 1.5k pixels.
References
Physics
History of technology
+ | History of the LED | [
"Technology"
] | 3,594 | [
"Science and technology studies",
"History of science and technology",
"History of technology"
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