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Voice frequency primary patch bay In telecommunication, a voice frequency primary patch bay (VF) is a patching facility that provides the first appearance of local-user VF circuits in the technical control facility (TCF). The VF primary patch bay provides patching, monitoring, and testing for all VF circuits. Signals will have various levels and signaling schemes depending on the user terminal equipment. | https://en.wikipedia.org/wiki?curid=41856 | 304,036 |
Multipoint control unit A multipoint control unit (MCU) is a device commonly used to bridge videoconferencing connections. The multipoint control unit is an endpoint on the LAN that provides the capability for three or more terminals and gateways to participate in a multipoint conference. The MCU consists of a mandatory multipoint controller (MC) and optional multipoint processors (MPs). | https://en.wikipedia.org/wiki?curid=2078819 | 294,328 |
Interband cascade laser Since the hole population tends to substantially exceed the electron population in undoped or moderately-doped ICLs, carrier rebalancing is achieved by heavily n-doping the electron injector (typically, with Si) so as to add electrons to the active QWs. The gain within a given waveguide required to reach the lasing threshold is given by the equation: where α is the waveguide loss, α is the mirror loss, and Γ is the optical confinement factor. The mirror loss is due to photons escaping through the mirrors of the optical resonator. Waveguide losses can be due to absorption in the active, separate confinement, optical cladding materials, and metal contacts (if the claddings are not thick enough), or result from scattering at the ridge sidewalls. The confinement factor is that percentage of the optical energy concentrated in the cascade stages. As with other semiconductor lasers, ICLs have a tradeoff between optical loss in the waveguide and Γ. The overall goal of waveguide design is to find the proper structure that minimizes the threshold gain. The choice of waveguide material depends on the substrate used. For ICLs grown on GaSb, the separate confinement layers are typically low-doped GaSb while the optical cladding layers are InAs/AlSb superlattices lattice-matched to the GaSb substrate. The bottom cladding must be fairly thick to prevent leakage of the guided mode into the substrate, since the refractive index of GaSb (about 3.8) is larger than the effective index of the lasing mode (typically 3.4-3.6) | https://en.wikipedia.org/wiki?curid=37769853 | 412,465 |
HD Tach is a software program for Microsoft Windows (2000 or XP) that tests and graphs the sequential read, random access and interface burst speeds of attached storage devices (hard drive, flash drive, removable drive etc.). Drive technologies such as SCSI, IDE/ATA, IEEE 1394, USB, SATA and RAID are supported. A prominent feature of the software was an included library of drive benchmarks, as well as the option to save your own drive's benchmarks locally or submit them to an online database. The company's website also had a forum with over 2000 user posts. On December 5, 2011, citing the lack of time to devote to the project, Simpli Software formally announced on its website that had reached end-of-life and was no longer being supported. The domain has since expired. The latest version of this application (3.0.4.0) is not fully compatible with Windows Vista, Windows 7, or Windows 8. However, works in these operating systems by running it in Windows XP SP2 or SP3 compatibility mode. 2.70 is the last version to work on Windows NT 4.0. was originally developed by TCD Labs, Inc. In 2000 the company was acquired by Oak Technology, Inc. Simpli Software, Inc. was formed by the original group of TCD Labs employees and acquired all rights to the benchmarks and source code from Oak Technology in 2003. The domain name displayed in the software, simplisoftware.com, began resolving to a domain reseller landing page in November 2012. | https://en.wikipedia.org/wiki?curid=8770352 | 103,903 |
Callus (cell biology) Nevertheless, callus cells are often considered similar enough for standard scientific analysis to be performed as if on a single subject. For example, an experiment may have half a callus undergo a treatment as the experimental group, while the other half undergoes a similar but non-active treatment as the control group. Plant calluses derived from many different cell types can differentiate into a whole plant, a process called regeneration, through addition of plant hormones to the culture medium. This ability is known as totipotency. Regeneration of a whole plant from a single cell allows transgenics researchers to obtain whole plants which have a copy of the transgene in every cell. Regeneration of a whole plant that has some genetically transformed cells and some untransformed cells yields a chimera. In general, chimeras are not useful for genetic research or agricultural applications. Genes can be inserted into callus cells using biolistic bombardment, also known as a gene gun, or "Agrobacterium tumefaciens". Cells that receive the gene of interest can then be recovered into whole plants using a combination of plant hormones. The whole plants that are recovered can be used to experimentally determine gene function(s), or to enhance crop plant traits for modern agriculture. Callus is of particular use in micropropagation where it can be used to grow genetically identical copies of plants with desirable characteristics | https://en.wikipedia.org/wiki?curid=1009199 | 145,749 |
Biopython PDB, one can navigate through individual components of a macromolecular structure file, such as examining each atom in a protein. Common analyses can be carried out, such as measuring distances or angles, comparing residues and calculating residue depth. The Bio.PopGen module adds support to for Genepop, a software package for statistical analysis of population genetics. This allows for analyses of Hardy–Weinberg equilibrium, linkage disequilibrium and other features of a population's allele frequencies. This module can also carry out population genetic simulations using coalescent theory with the fastsimcoal2 program. Many of Biopython's modules contain command line wrappers for commonly used tools, allowing these tools to be used from within Biopython. These wrappers include BLAST, Clustal, PhyML, EMBOSS and SAMtools. Users can subclass a generic wrapper class to add support for any other command line tool. | https://en.wikipedia.org/wiki?curid=559868 | 167,446 |
Nuclear safety and security It was concentrated in leafy vegetation after absorption in the soil. It also stays in animals’ milk if the animals eat the vegetation. When Iodine 131 enters the human body, it migrates to the thyroid gland in the neck and can cause thyroid cancer. Other elements from nuclear waste can lead to cancer as well. For example, Strontium 90 causes breast cancer and leukemia, Plutonium 239 causes liver cancer. Redesigns of fuel pellets and cladding are being undertaken which can further improve the safety of existing power plants. Newer reactor designs intended to provide increased safety have been developed over time. These designs include those that incorporate passive safety and Small Modular Reactors. While these reactor designs "are intended to inspire trust, they may have an unintended effect: creating distrust of older reactors that lack the touted safety features". The next nuclear plants to be built will likely be Generation III or III+ designs, and a few such are already in operation in Japan. Generation IV reactors would have even greater improvements in safety. These new designs are expected to be passively safe or nearly so, and perhaps even inherently safe (as in the PBMR designs) | https://en.wikipedia.org/wiki?curid=4222539 | 276,479 |
Thermochromism The acids include bisphenol A, parabens, 1,2,3-triazole derivates, and 4-hydroxycoumarin and act as proton donors, changing the dye molecule between its leuco form and its protonated colored form; stronger acids would make the change irreversible. Leuco dyes have less accurate temperature response than liquid crystals. They are suitable for general indicators of approximate temperature ("too cool", "too hot", "about OK"), or for various novelty items. They are usually used in combination with some other pigment, producing a color change between the color of the base pigment and the color of the pigment combined with the color of the non-leuco form of the leuco dye. Organic leuco dyes are available for temperature ranges between about and , in wide range of colors. The color change usually happens in a 3 °C (5.4 °F) interval. Leuco dyes are used in applications where temperature response accuracy is not critical: e.g. novelties, bath toys, flying discs, and approximate temperature indicators for microwave-heated foods. Microencapsulation allows their use in wide range of materials and products. The size of the microcapsules typically ranges between 3–5 µm (over 10 times larger than regular pigment particles), which requires some adjustments to printing and manufacturing processes. An application of leuco dyes is in the Duracell battery state indicators. A layer of a leuco dye is applied on a resistive strip to indicate its heating, thus gauging the amount of current the battery is able to supply | https://en.wikipedia.org/wiki?curid=1584732 | 97,904 |
Deep underground However, due to technical difficulties in ventilation, emergency procedures and other safety-related issues and the relatively high cost, no projects using deep underground have been completed as of 2010. In the case of public use, no compensation to the land owner is required. | https://en.wikipedia.org/wiki?curid=23210832 | 341,862 |
Occupational safety and health "Occupational health should aim at: the promotion and maintenance of the highest degree of physical, mental and social well-being of workers in all occupations; the prevention amongst workers of departures from health caused by their working conditions; the protection of workers in their employment from risks resulting from factors adverse to health; the placing and maintenance of the worker in an occupational environment adapted to his physiological and psychological capabilities; and, to summarize, the adaptation of work to man and of each man to his job. The research and regulation of occupational safety and health are a relatively recent phenomenon. As labor movements arose in response to worker concerns in the wake of the industrial revolution, worker's health entered consideration as a labor-related issue. In the United Kingdom, the Factory Acts of the early nineteenth century (from 1802 onwards) arose out of concerns about the poor health of children working in cotton mills: the Act of 1833 created a dedicated professional Factory Inspectorate. The initial remit of the Inspectorate was to police restrictions on the working hours in the textile industry of children and young persons (introduced to prevent chronic overwork, identified as leading directly to ill-health and deformation, and indirectly to a high accident rate) | https://en.wikipedia.org/wiki?curid=35319154 | 475,745 |
February 13, 1979 windstorm It took nearly three years and over $140 million U.S. to rebuild the lost bridge. | https://en.wikipedia.org/wiki?curid=1202383 | 2,437 |
Porphyry copper deposit This interaction between subduction zones and the aforementioned oceanic features can explain the development of multiple metallogenic belts in a given region; as each time the subduction zone interacts with one of these features it can lead to ore genesis. Finally, in oceanic island arcs, ridge subduction can lead to slab flattening or arc reversal; whereas, in continental arcs it can lead to periods of Flat Slab Subduction. Arc reversal has been shown to slightly pre-date the formation of porphyry deposits in the south-west Pacific, after a collisional event. Arc reversal occurs due to collision between an island arc and either another island arc, a continent, or an oceanic plateau. The collision may result in the termination of subduction and thereby induce mantle melting. Porphyry deposits do not generally have any requisite structural controls for their formation; although major faults and lineaments are associated with some. The presence of intra-arc fault systems are beneficial, as they can localize porphyry development. Furthermore, some authors have indicated that the occurrence of intersections between continent-scale traverse fault zones and arc-parallel structures are associated with porphyry formation. This is actually the case of Chile's Los Bronces and El Teniente porphyry copper deposits each of which lies at the intersection of two fault systems. Characteristics of porphyry copper deposits include: Porphyry copper deposits are typically mined by open-pit methods | https://en.wikipedia.org/wiki?curid=3049753 | 66,488 |
Preservative Drying prevents yeasts and bread molds ("Rhizopus") from growing by removing moisture so bacteria cannot grow. Cellars, caves, and cool streams were used for freezing. American estates had ice houses built to store ice and food on the ice. The icehouse was then converted to an “icebox”. The Icebox was converted in the 1800s to mechanical refrigeration. Clarence Birdseye found in the 1800s that freezing meats and vegetables at a low temperature made them taste better. Fermenting was discovered when a few grains of barley were left in the rain and turned into beer. Microorganisms ferment the starch-derived sugars into alcohols. This is also how fruits are fermented into wine and cabbage into Kimchi or sauerkraut. Anthropologists believe that as early as 10,000 B.C people began to settle and grow barley. They began to make beer and believed that it was a gift from gods. It was used to preserve foods and to create more nutritious foods from less desirable ingredients. Vitamins are produced through fermentation by microorganisms making the end product more nutritious. Pickling occurs when foods are placed in a container with vinegar or another acid. It is thought that pickling came about when people used to place food in wine or beer to preserve it due to them having a low pH. Containers had to be stoneware or glass (vinegar will dissolve metal from pots). After the food was eaten, the pickling brine had other uses. Romans would make a concentrated pickle sauce called “garum” | https://en.wikipedia.org/wiki?curid=24862 | 96,779 |
Phases of clinical research Phase IV studies may be required by regulatory authorities or may be undertaken by the sponsoring company for competitive (finding a new market for the drug) or other reasons (for example, the drug may not have been tested for interactions with other drugs, or on certain population groups such as pregnant women, who are unlikely to subject themselves to trials). The safety surveillance is designed to detect any rare or long-term adverse effects over a much larger patient population and longer time period than was possible during the Phase I-III clinical trials. Harmful effects discovered by Phase IV trials may result in a drug being no longer sold, or restricted to certain uses; recent examples involve cerivastatin (brand names Baycol and Lipobay), troglitazone (Rezulin) and rofecoxib (Vioxx). The minimum time period mandatory for Phase IV clinical trials is 2 years. The entire process of developing a drug from preclinical research to marketing can take approximately 12 to 18 years and often costs well over $1 billion. | https://en.wikipedia.org/wiki?curid=34382035 | 179,334 |
Dragons' Den (British TV programme) In the final episode of Series 11, after accepting Peter Jones and Deborah Meaden's offer of £50,000 for 40% (later 30%) of his company Bobo Buddies, James Roupell rejected the deal after filming. In Series 12, Daniel and Mat of Pure Pet Food turned down both Deborah Meaden and Kelly Hoppen's offers of £40,000 for 30% and 20% respectively. Also in Series 12, owner of gourmet marshmallow company Mallow & Marsh, Harriet Pleydell-Bouverie, turned down both Peter Jones and Deborah Meaden who wanted 40% and 33⅓% of the company respectively in exchange for £65,000 (later £80,000 from Jones). In Episode 10, Cally Russell rejected Peter Jones' offer of £75,000 for 20% of his company Mallzee, a mobile shopping app, even after Jones offered to drop his share to 15% once the investment was returned. In series 13, Ellen Green, director of the Blue Badge Company, declined Touker Suleyman's offer of £70,000 for 35% of her company. Also in Series 13, Jo Hilditch rejected Peter Jones' offer of £50,000 for 30% of her wine-making company, British Cassis. In episode 10 of the same series, Roy Fitter rejected Peter Jones' offer of £80,000 for 30% of his company, Ram Training Ltd, a horror events company. In Episode 13, Yann Morvan and Richard Lee rejected Peter Jones and Nick Jenkins' offer of £75,000 for 30% of their portable drumming business Aerodrums | https://en.wikipedia.org/wiki?curid=12617978 | 490,809 |
SystemVerilog introduces three new procedural blocks intended to model hardware: codice_17 (to model combinational logic), codice_18 (for flip-flops), and codice_19 (for latches). Whereas Verilog used a single, general-purpose codice_20 block to model different types of hardware structures, each of SystemVerilog's new blocks is intended to model a specific type of hardware, by imposing semantic restrictions to ensure that hardware described by the blocks matches the intended usage of the model. An HDL compiler or verification program can take extra steps to ensure that only the intended type of behavior occurs. An codice_17 block models combinational logic. The simulator infers the sensitivity list to be all variables from the contained statements: An codice_19 block is meant to infer a level-sensitive latch. Again, the sensitivity list is inferred from the code: An codice_18 block is meant to model synchronous logic (especially edge-sensitive sequential logic): Electronic design automation (EDA) tools can verify the design's intent by checking that the hardware model does not violate any block usage semantics. For example, the new blocks restrict assignment to a variable by allowing only one source, whereas Verilog's codice_20 block permitted assignment from multiple procedural sources. For small designs, the Verilog "port" compactly describes a module's connectivity with the surrounding environment. But major blocks within a large design hierarchy typically possess port counts in the thousands | https://en.wikipedia.org/wiki?curid=2540686 | 415,860 |
Inmarsat Other services provide mobile Integrated Services Digital Network (ISDN) services used by the media for live reporting on world events via videophone, and inflight Internet access via the European Aviation Network. The price of a call via has now dropped to a level where they are comparable to, and in many cases lower than, international roaming costs, or hotel phone calls. Voice call charges are the same for any location in the world where the service is used. Tariffs for calls to country codes vary, depending on the country in which they are placed. primarily uses country code 870 (see below). Newer services use an IP technology that features an always-on capability where the users are only charged for the amount of data they send and receive, rather than the length of time they are connected. In addition to its own satellites, has a collaboration agreement with ACeS regarding handheld voice services. There are three types of coverage related to each I-4 satellite. The I-5 satellites provide global coverage using four geostationary satellites. Each satellite supports 89 beams, giving a total coverage of approximately one-third of the Earth's surface per satellite. In addition, 6 steerable beams are available per satellite, which may be moved to provide higher capacity to selected locations. On 26 November 2019, the first satellite to extend the original 4 satellite first generation Global Xpress constellation was launched from Guiana Space Centre by an Ariane 5 rocket | https://en.wikipedia.org/wiki?curid=5952567 | 252,123 |
Loudspeaker In 1954, Edgar Villchur developed the acoustic suspension principle of loudspeaker design in Cambridge, Massachusetts. This allowed for better bass response than previously from drivers mounted in smaller cabinets which was important during the transition to stereo recording and reproduction. He and his partner Henry Kloss formed the Acoustic Research company to manufacture and market speaker systems using this principle. Subsequently, continuous developments in enclosure design and materials led to significant audible improvements. The most notable improvements to date in modern dynamic drivers, and the loudspeakers that employ them, are improvements in cone materials, the introduction of higher-temperature adhesives, improved permanent magnet materials, improved measurement techniques, computer-aided design, and finite element analysis. At low frequencies, the application of electrical network theory to the acoustic performance allowed by various enclosure designs (initially by Thiele, and later by Small) has been very important at the design level. The most common type of driver, commonly called a dynamic loudspeaker, uses a lightweight diaphragm, or "cone", connected to a rigid "basket", or "frame", via a flexible suspension, commonly called a "spider", that constrains a voice coil to move axially through a cylindrical magnetic gap. A protective cap glued in the cone's center prevents dust, especially iron filings, from entering the gap | https://en.wikipedia.org/wiki?curid=45871 | 207,499 |
DO-254 The planning process is the first step where the design authority (the company who develops the H/W and implements the COTS into its design) declares its approach towards the certification. At this point the PHAC (Plan for H/W Aspects of Certification) is presented to the authorities (EASA, FAA...). In this plan, the developer presents its approach and how DO-254/ED-80 is implemented. The PHAC is submitted as part of the authorities 1st stage of involvement (SOI#1). The hardware requirement validation process provides assurance that the hardware item derived requirements are correct and complete with respect to system requirements allocated to the hardware item. Validation of hardware requirements allocated from system requirements is a system process, rather than a hardware process. As such, hardware requirements that are derived by hardware processes should be identified to system processes for validation against the system requirements. For the purposes of this document's processes, a requirement is complete when all the attributes that have been defined are necessary and that all the necessary attributes have been defined, and a requirement is correct when the requirement is defined without ambiguity and there are no errors in the defined attributes. The verification process provides assurance that the hardware item implementation meets all of the hardware requirements, including derived requirements. Methods of verification include qualitative review, quantitative analysis, and functional testing | https://en.wikipedia.org/wiki?curid=3296562 | 109,148 |
Traditionalist Worker Party Heimbach and his group advocate white separatism, and the group also adheres to a white nationalist and white supremacist ideology. Heimbach and Parrott are "self-declared ethnonationalists" who aim to create a separate white ethnostate. The group specifically promotes a white supremacist interpretation of Christianity, recruiting members to battle what it terms "anti-Christian degeneracy." The group supports the prohibition of abortion, restrictions on immigration, and ultimately the carrying out of what Heimbach describes as "peaceful secessionist projects." Heimbach has been described in media reports as an "alt-right personality". The SPLC describes the group's ideology as being "virulently racist and anti-Semitic." Both the SPLC and the Anti-Defamation League note that the group is modeled after the European Identitarian movement. The TWP proclaims itself to be "against modernism, individualism, globalism and Marxism." The group identifies itself as an anti-capitalist organization and it connects this position to its advocacy of nationalism stating "For us, to be anti-capitalist is to be a nationalist. Nationalism is a bulwark against capitalist exploitation and globalism." In 2016, Heimbach hailed the British vote to leave the European Union as "the greatest European nationalist victory since 1933," the year of the Nazi rise to power in Germany. In 2016, the TWP and the "Barnes Review", a Holocaust denial publication, announced a partnership to promote each other | https://en.wikipedia.org/wiki?curid=48849657 | 473,518 |
Naranjo algorithm The Naranjo algorithm, Naranjo Scale, or Naranjo Nomogram is a questionnaire designed by Naranjo "et al." for determining the likelihood of whether an ADR (adverse drug reaction) is actually due to the drug rather than the result of other factors. Probability is assigned via a score termed definite, probable, possible or doubtful. Values obtained from this algorithm are often used in peer reviews to verify the validity of author's conclusions regarding adverse drug reactions. It is also called the Naranjo Scale or Naranjo Score. It is often compared to the WHO-UMC system for standardized causality assessment for suspected adverse drug reactions (ADRs). Empirical approaches to identifying ADRs have fallen short because of the complexity of the set of variables involved in their detection. Computer decision programs have helped in this analysis. Electronic medical record systems can be programmed to fire alerts when a potential adverse drug event is about to occur or has already occurred.[3,4] Automated adverse drug event monitors can search for keywords or phrases throughout the patient's medical record to identify drug therapies, laboratory results, or problem lists that may indicate that a patient has already been treated for an ADR. This detection method uncovers significantly more adverse events, including medication errors, than relying on empirical methods or incident reports.[1,2] Empirical methods to assess the likelihood that an ADR has taken place have been lacking | https://en.wikipedia.org/wiki?curid=12515271 | 89,288 |
Sewer alligator stories date back to the late 1920s and early 1930s; in most instances they are part of contemporary legend. They are based upon reports of alligator sightings in rather unorthodox locations, in particular New York City. "The New York Times" reports the city rescues several alligators per year, some directly from homes where they are kept as illegal pets (which can be legally ordered online in other states and are legal to mail when small), and some from outside (where they can attract considerable attention) though mostly above-ground. Though escapees and former pets may survive for a short time in New York sewers, longer-term survival is not possible due to low temperatures and the bacteria in human feces. Sewer maintenance crews have confirmed there is no underground population. A similar story from 1851 involves feral pigs in the sewers of Hampstead, London. Following the reports of sewer alligators in the 1930s, the story has built up over the decades and become more of a contemporary legend. Many have even questioned how accurate the original stories are, and some have even suggested they are fictions created by Teddy May, who was the Commissioner of Sewers at the time. Interviews with him were the basis of the first published accounts of sewer alligators. However, the story of the "sewer gator" in New York City is well known and various versions have been told. As late as the middle of the 20th century, souvenir shops in Florida sold live baby alligators (in small fish tanks) as novelty souvenirs | https://en.wikipedia.org/wiki?curid=2997965 | 312,142 |
Inertial audio effects controller However, currently the only commercially available products use acceleration sensing only or acceleration combined with angular velocity, as sensed by a gyroscope. Inertial control of an audio device, wired or wireless, is a relatively recent and growing trend as technology advances have reduced pricing and size as well as improved usability and performance of the core components. Specifically the core components are an inertial device called a Mirco- Electro-Mechanical-System (MEMs), a microcontroller, and for wireless systems, a radio frequency transmitter/receiver. | https://en.wikipedia.org/wiki?curid=55813510 | 390,828 |
Swisscom-Sendeturm St. Chrischona On the north side is a construction similar to a “backpack” which has a height of 103 m; and two drinking water tanks that are 100 s high that contain water supplies for the municipality of Bettingen. During the construction, the weight of the water had to be included in the tension of the tower, which is why it stood southwardly inclined before the completion. The tower stands on a base construction which includes three basements which accommodate company / technical equipment. Because the location of the tower lies in the seismic zone of Basel – Erdbebengebiet in the Upper Rhine district, this has been built especially securely about the base. The tower should remain stable in an earthquake up to 8 on the Richter scale. The television tower was under construction from July 1980 until December 1983, and was put into operation on 2 August 1984. It replaced a 136 m high steel radio tower that was built in 1962 in Beromünster, where it carried an antenna for medium wave transmission, like today's backup broadcasting tower. Saint Chrischona was already in use since 1954, a broadcasting tower that was 30 m high at that time which transferred the Swiss television program up to this time. Today's tower of Saint Chrischona carries broadcasting antennas for Swiss Radio (DRS) and the “Southwest German Radio” (SWR). Because of this unique construction, it is said that the tower could remain standing during the high winds of a hurricane, where wind speeds appear up to 220 km/h, with an oscillation of only 40 cm. | https://en.wikipedia.org/wiki?curid=838723 | 310,159 |
Mach reflection is a supersonic fluid dynamics effect, named for Ernst Mach, and is a shock wave reflection pattern involving three shocks. can exist in steady, pseudo-steady and unsteady flows. When a shock wave, which is moving with a constant velocity, propagates over a solid wedge, the flow generated by the shock impinges on the wedge thus generating a second reflected shock, which ensures that the velocity of the flow is parallel to the wedge surface. Viewed in the frame of the reflection point, this flow is locally steady, and the flow is referred to as pseudosteady. When the angle between the wedge and the primary shock is sufficiently large, a single reflected shock is not able to turn the flow to a direction parallel to the wall and a transition to occurs. In a steady flow situation, if a wedge is placed into a steady supersonic flow in such a way that its oblique attached shock impinges on a flat wall parallel to the free stream, the shock turns the flow toward the wall and a reflected shock is required to turn the flow back to a direction parallel to the wall. When the shock angle exceeds a certain value, the deflection achievable by a single reflected shock is insufficient to turn the flow back to a direction parallel to the wall and transition to is observed. consists of three shocks, namely the incident shock, the reflected shock and a Mach stem, as well as a slip plane. The point where the three shocks meet is known as the 'triple point' in two dimensions, or a shock-shock in three dimensions | https://en.wikipedia.org/wiki?curid=11053791 | 81,438 |
Hidden Markov model Yet another variant is the "factorial hidden Markov model", which allows for a single observation to be conditioned on the corresponding hidden variables of a set of formula_37 independent Markov chains, rather than a single Markov chain. It is equivalent to a single HMM, with formula_38 states (assuming there are formula_39 states for each chain), and therefore, learning in such a model is difficult: for a sequence of length formula_40, a straightforward Viterbi algorithm has complexity formula_41. To find an exact solution, a junction tree algorithm could be used, but it results in an formula_42 complexity. In practice, approximate techniques, such as variational approaches, could be used. All of the above models can be extended to allow for more distant dependencies among hidden states, e.g. allowing for a given state to be dependent on the previous two or three states rather than a single previous state; i.e. the transition probabilities are extended to encompass sets of three or four adjacent states (or in general formula_37 adjacent states). The disadvantage of such models is that dynamic-programming algorithms for training them have an formula_44 running time, for formula_37 adjacent states and formula_40 total observations (i.e. a length-formula_40 Markov chain). Another recent extension is the "triplet Markov model", in which an auxiliary underlying process is added to model some data specificities. Many variants of this model have been proposed | https://en.wikipedia.org/wiki?curid=98770 | 192,845 |
Cell-penetrating peptide "In vivo" administration of these agents allows the labeling of tumor cells; or cells can be labeled "in vitro" with contrast agents and then they can be injected and monitored "in vivo" by using MRI techniques. SPIO nanoparticles confer high sensitivity in MRI but they have lower affinity for cells; they work at high concentrations. Functionalizations of these compounds using dendrimeric guanidines showed similar activities as TAT-based CPPs but higher toxicity. New substrates based on dendrons with hydroxyl or amine peripheries show low toxicity. Applications of SPIO includes cell labeling "in vivo"; due to low toxicity, they are clinically approved for use in liver, spleen, and gastrointestinal imaging. The presence of octamer arginine residues allows cell membrane transduction of various cargo molecules including peptides, DNA, siRNA, and contrast agents. However, the ability of cross membrane is not unidirectional; arginine-based CPPs are able to enter-exit the cell membrane, displaying an overall decreasing concentration of contrast agent and a decrease of magnetic resonance (MR) signal in time. This limits their application "in vivo". To solve this problem, contrast agents with disulfide, reversible bond between metal chelate and transduction moiety enhance the cell-associated retention. The disulfide bond is reduced by the target cell environment and the metal chelate remains trapped in the cytoplasm, increasing the retention time of chelate in the target cell. | https://en.wikipedia.org/wiki?curid=9470331 | 153,428 |
Radiosonde By 1940, the NBS radiosonde system included a pressure drive, which measured temperature and humidity as functions of pressure. It also gathered data on cloud thickness and light intensity in the atmosphere. Due to this and other improvements in cost (about $25), weight (> 1 kilogram), and accuracy, hundreds of thousands of NBS-style radiosondes were produced nationwide for research purposes, and the apparatus was officially adopted by the U.S. Weather Bureau. Diamond was given the Washington Academy of Sciences Engineering Award in 1940 and the IRE Fellow Award (which was later renamed the Harry Diamond Memorial Award) in 1943 for his contributions to radio-meteorology. The expansion of economically important government weather forecasting services during the 1930s and their increasing need for data motivated many nations to begin regular radiosonde observation programs In 1985, as part of the Soviet Union's Vega program, the two Venus probes, Vega 1 and Vega 2, each dropped a radiosonde into the atmosphere of Venus. The sondes were tracked for two days. Although modern remote sensing by satellites, aircraft and ground sensors is an increasing source of atmospheric data, none of these systems can match the vertical resolution ( or less) and altitude coverage () of radiosonde observations, so they remain essential to modern meteorology. Although hundreds of radiosondes are launched worldwide each day year-round, fatalities attributed to radiosondes are rare | https://en.wikipedia.org/wiki?curid=172851 | 225,915 |
History of children in the military Orphans of the Imperial Guard fought in the Netherlands with Marshal MacDonald and were between the ages of 14 and 17. Many of the conscripts who reported to the ranks in 1814 were referred to as Marie Louises after the Empress Marie Louise of France; they were also known as "The Infants of the Emperor". These soldiers were in their mid-teens. One of their more visible roles was as the ubiquitous "drummer boy". During the age of sail, young boys formed part of the crew of British Royal Navy ships and were responsible for many essential tasks including bringing powder and shot from the ship's magazine to the gun crews. These children were called "powder monkeys." During the American Civil War a young boy, Bugler John Cook, served in the US Army at the age of 15 and received the Medal of Honor for his acts during the Battle of Antietam, the bloodiest day in American history. Several other minors, including 11-year-old Willie Johnston, have also received the Medal of Honor. By a law signed by Nicholas I of Russia in 1827 a disproportionate number of Jewish boys, known as the cantonists, were forced into military training establishments to serve in the army. The 25-year conscription term officially commenced at the age of 18, but boys as young as eight were routinely taken to fulfill the quota. In the final stages of the Paraguayan War, children fought in the Battle of Acosta Ñu against the Allied forces of Brazil, Argentina and Uruguay. The day is commemorated as a national holiday in Paraguay | https://en.wikipedia.org/wiki?curid=56921904 | 469,167 |
Living systems Not just those specialized in international communication, but all communication science scholars could pay particular attention to the major contributions of living systems theory (LST) to social systems approaches that Bailey has pointed out: Bailey says that LST, perhaps the "most integrative" social systems theory, has made many more contributions that may be easily overlooked, such as: providing a detailed analysis of types of systems; making a distinction between concrete and abstracted systems; discussion of physical space and time; placing emphasis on information processing; providing an analysis of entropy; recognition of totipotential systems, and partipotential systems; providing an innovative approach to the structure–process issue; and introducing the concept of joint subsystem—a subsystem that belongs to two systems simultaneously; of dispersal—lateral, outward, upward, and downward; of inclusion—inclusion of something from the environment that is not part of the system; of artifact—an animal-made or human-made inclusion; of adjustment process, which combats stress in a system; and of critical subsystems, which carry out processes that all living systems need to survive. LST's analysis of the twenty interacting subsystems, Bailey adds, clearly distinguishing between matter–energy-processing and information-processing, as well as LST's analysis of the eight interrelated system levels, enables us to understand how social systems are linked to biological systems | https://en.wikipedia.org/wiki?curid=16554664 | 171,689 |
Great Industrial Exhibition (1853) The Great Industrial Exhibition in 1853 was held in Dublin, Ireland. In its day, it was the largest international event to be held in Ireland. The Irish Industrial Exhibition Building, located on the grounds of Leinster House, housed the entire fair. It lasted from 12 May to 31 October, Queen Victoria accompanied by the Prince Consort and the Prince of Wales, paid an official visit on 29 August. It was entirely funded by William Dargan, entrepreneur and developer of Irish railways. He had planned to donate $100,000 to the effort, but ended up giving $400,000. The intent of the exhibition was to introduce the industrial revolution to Ireland, which was behind some other European countries. Visitors were struck with the richness and splendor of the building more than by any of the objects that it contained. Critics described the large exhibition building and "the rapidity with which it was erected" (a few months), and "the sufficiency of its plans, and the enormous mass of its carefully worked materials." The building is described by The Illustrated Dublin Exhibition Catalogue as: On 12 May 1853, when the exhibition opened, the architect (who had also been the architect for the industrial exhibition held in Cork the previous year), John Benson, was granted a knighthood. Part of the roof blew off during a storm on Christmas Eve, the year before opening. Some limited Irish furniture industry was shown, including the linen and lace industry which the Irish could identify with | https://en.wikipedia.org/wiki?curid=1755827 | 292,778 |
Jurin's law Yet the pressure at this point follows a vertical pressure variation as where formula_18 is the gravitational acceleration and formula_19 the density of the liquid. This equation means that the pressure at point formula_15 is the pressure at the interface plus the pressure due to the weight of the liquid column of height formula_5. In this way, we can calculate the pressure at the convex interface formula_22 The hydrostatic analysis shows that formula_23, combining this with the Laplace pressure calculation we have:formula_24solving for formula_5 returns Jurin's law. | https://en.wikipedia.org/wiki?curid=30639331 | 445,207 |
Reinforced concrete Steel is the strongest commonly available fiber, and comes in different lengths (30 to 80 mm in Europe) and shapes (end-hooks). Steel fibers can only be used on surfaces that can tolerate or avoid corrosion and rust stains. In some cases, a steel-fiber surface is faced with other materials. Glass fiber is inexpensive and corrosion-proof, but not as ductile as steel. Recently, spun basalt fiber, long available in Eastern Europe, has become available in the U.S. and Western Europe. Basalt fibre is stronger and less expensive than glass, but historically has not resisted the alkaline environment of Portland cement well enough to be used as direct reinforcement. New materials use plastic binders to isolate the basalt fiber from the cement. The premium fibers are graphite-reinforced plastic fibers, which are nearly as strong as steel, lighter in weight, and corrosion-proof. Some experiments have had promising early results with carbon nanotubes, but the material is still far too expensive for any building. There is considerable overlap between the subjects of non-steel reinforcement and fiber-reinforcement of concrete. The introduction of non-steel reinforcement of concrete is relatively recent; it takes two major forms: non-metallic rebar rods, and non-steel (usually also non-metallic) fibres incorporated into the cement matrix. For example, there is increasing interest in glass fiber reinforced concrete (GFRC) and in various applications of polymer fibres incorporated into concrete | https://en.wikipedia.org/wiki?curid=54232 | 207,796 |
Academic Health Science Networks As part of the "Sunset Review" a number of initiatives closed in 2013 including the NHS National Innovation Centre, NHS Institute for Innovation and Improvement, and Health Innovation and Education Clusters (HIECs). There is still a range of currently active initiatives including NHS Innovation Hubs, NHS Supply Chain Innovation and NHS Improvement. Core funding will come from NHS England and work was "in hand to identify the funding" when expressions of interest were invited. A briefing paper assumed funding to be in the region of £2 per head of population served. With a population averaging 3m people, a typical AHSN might have expected roughly £6m per AHSN per year. These figures reflect early expectations but were neither clarified nor confirmed with the designation announcement. When contracts were signed with NHS England in November 2013, the 15 AHSNs shared around £60 million of funding. Although their purpose is clear, the structure and approach of individual AHSNs is a matter for local decision. This is apparent in the contrasting approaches taken and the variety of opinions expressed by network founders. As membership organisations, AHSNs do not have any direct authority over their members, but Innovation Health and Wealth states: "all NHS organisations will aspire to be affiliated to their local AHSN where the AHSN will operate as a gateway for the NHS on innovation and working with the life sciences industry on the evaluation, commercialisation and rapid adoption of health technologies" | https://en.wikipedia.org/wiki?curid=39580391 | 165,990 |
Faraday cup In this case, the elementary particle current formula_24 corresponding to the ion density differential formula_25 in the range of velocities between formula_26 and formula_27 of ions flowing in through operating aperture formula_28 of the electron-suppressor can be written in the form where formula_29 is elementary charge, formula_30 is the ion charge state, and formula_31 is the one-dimensional ion velocity distribution function. Therefore, the ion current at the ion-decelerating voltage formula_20 of the can be calculated by integrating Eq. () after substituting Eq. (), where the lower integration limit is defined from the equation formula_33 where formula_34 is the velocity of the ion stopped by the decelerating potential formula_20, and formula_36 is the ion mass. Thus Eq. () represents the I-V characteristic of the Faraday cup. Differentiating Eq. () with respect to formula_20, one can obtain the relation where the value formula_38 is an invariable constant for each measurement. Therefore, the average velocity formula_39 of ions arriving into the and their average energy formula_40 can be calculated (under the assumption that we operate with a single type of ion) by the expressions where formula_41 is the ion mass in atomic units. The ion concentration formula_42 in the ion flow at the vicinity can be calculated by the formula which follows from Eq. () at formula_43, and from the conventional condition for distribution function normalizing Fig | https://en.wikipedia.org/wiki?curid=1777422 | 292,882 |
North polar sequence The is a group of 96 stars that was used to define stellar magnitudes and colors. The cluster of stars lies within two degrees of the Northern Celestial pole. That fact makes them visible to everyone in the northern hemisphere. Originally proposed by Edward Charles Pickering, the system was used between 1900 and 1950. Today it has been replaced by the UBV photometric system. | https://en.wikipedia.org/wiki?curid=24379121 | 10,863 |
Polymer capacitor Heeger and F. Wudl of an organic conductor, the charge-transfer salt TCNQ. TCNQ (7,7,8,8-tetracyanoquinodimethane or N-n-butyl isoquinolinium in combination with TTF (Tetrathiafulvalene)) is a chain molecule of almost perfect one-dimensional structure that has a 10-fold better conductivity along the chains than does MnO, and has a 100-fold better conductivity than non-solid electrolytes. The first Al-e-caps to use the charge transfer salt TTF-TCNQ as a solid organic electrolyte was the OS-CON series offered in 1983 from Sanyo. These were wound, cylindrical capacitors with 10x increased electrolyte conductivity compared with MnO These capacitors were used in devices for applications that required the lowest possible ESR or highest possible ripple current. One OS-CON e-cap could replace three more bulky "wet" e-caps or two Ta-caps. By 1995, the Sanyo OS-CON became the preferred decoupling capacitor for Pentium processor-based IBM personal computers. The Sanyo OS-CON e-cap product line was sold in 2010 to Panasonic. Panasonic then replaced the TCNQ salt with a conducting polymer under the same brand. The next step in ESR reduction was the development of conducting polymers by Alan J. Heeger, Alan MacDiarmid and Hideki Shirakawa in 1975. The conductivity of conductive polymers such as polypyrrole (PPy) or PEDOT is better than that of TCNQ by a factor of 100 to 500, and close to the conductivity of metals | https://en.wikipedia.org/wiki?curid=27956705 | 414,298 |
Civilekonom Civilekonom, literally "civil economist", is a professional title in Sweden (with corresponding titles in Denmark and Norway, see below) which traditionally refers to an individual who holds either a Bachelor's degree or a Master's degree in business administration and economics (with a major in business administration and a minor in economics, or vice versa). Unlike the English language usage, in Swedish, "ekonomi" ("economy") is commonly used as an umbrella designation for both business- and economics-related subjects. As an academic title it was first introduced by the Stockholm School of Economics for the degree that the school offered, and was created in parallel to the already established engineering degree , which etymologically is the same as the English expression civil engineer. Formally, the exam certificate for a "civilekonom" would say "ekonomexamen" ("degree in economy"), or be a general Bachelor's ("kandidat") or Master's ("magister") degree. Although the title remains unprotected in Sweden and the aforementioned practice is still in use, as of 2007 a new academic degree called "Civilekonomexamen" (Master of Science in Business and Economics) has been introduced which can be awarded after four years of studies in business administration and economics by the following universities in Sweden: | https://en.wikipedia.org/wiki?curid=13931631 | 511,861 |
World Trade Organization Likewise, in many of these same PTAs we find that substantial portions of treaty language—sometime the majority of a chapter—is copied verbatim from a WTO agreement... the presence of the WTO in PTAs has increased over time." | https://en.wikipedia.org/wiki?curid=33873 | 465,544 |
Vaccine bath A vaccine bath is an apparatus used in vaccine production. As vaccines are very heat labile but inevitably need to be heated to some extent, these devices are used. These are basically water baths, with a temperature set very low. A long time is taken to sterilize vaccines by this method. Bacterial vaccine are sterilized at 60°C for an hour. | https://en.wikipedia.org/wiki?curid=17200206 | 171,989 |
Rolling-element bearing More specifically, life models are used to determine the bearing size – since this must be sufficient to ensure that the bearing is strong enough to deliver the required life under certain defined operating conditions. Under controlled laboratory conditions, however, seemingly identical bearings operating under identical conditions can have different individual endurance lives. Thus, bearing life cannot be calculated based on specific bearings, but is instead related to in statistical terms, referring to populations of bearings. All information with regard to load ratings is then based on the life that 90% of a sufficiently large group of apparently identical bearings can be expected to attain or exceed. This gives a clearer definition of the concept of bearing life, which is essential to calculate the correct bearing size. Life models can thus help to predict the performance of a bearing more realistically. The prediction of bearing life is described in ISO 281 and the ANSI/American Bearing Manufacturers Association Standards 9 and 11. The traditional method to estimate the life of the rolling-element bearings uses the basic life equation: Where: Basic life or formula_2 is the life that 90% of bearings can be expected to reach or exceed. The median or average life, sometimes called Mean Time Between Failure (MTBF), is about five times the calculated basic rating life | https://en.wikipedia.org/wiki?curid=627542 | 37,397 |
American historic carpentry jpg|thumb|left|Over 5,000 relief cottages after the 1906 San Francisco earthquake were built using single-wall construction]] Box houses (boxed house, box frame, box and strip, piano box, single-wall, board and batten, and many other names) have minimal framing in the corners and widely spaced in the exterior walls, but like the vertical plank wall houses, the vertical boards are structural. The origins of boxed construction is unknown. The term "box-frame" was used in a reconstruction manual in 1868 after the American Civil War. "Box house" may also be a nickname for "Classic Box" or "[[American Foursquare]]" architectural styles in North America, and is also not to be confused with a general type of timber framing called a box frame. A variation on boxed construction is used on the [[Wesleyan Grove]] cottage: cottages around Oak Bluffs (Cottage City), Martha's Vineyard, Massachusetts, are built of vertical, tongue and groove planks without battens usually in a gothic style. This method was “inspired by the tent frame construction” of the original "board tents" used for Methodist [[Camp Meeting]]s beginning in 1835. An A-frame building has framing with little or no walls, the rafters join at the ridge forming an A shape. This is the simplest type of framing but has historically been used for inexpensive cottages and farm shelters until the [[A-frame house]] was popularized in the 1950s as a style of vacation home in the United States | https://en.wikipedia.org/wiki?curid=42451997 | 242,666 |
Lignin It can thus be seen that lignin is handled on a very large scale. is an impediment to papermaking as it is colored, it yellows in air, and its presence weakens the paper. Once separated from the cellulose, it is burned as fuel. Only a fraction is used in a wide range of low volume applications where the form but not the quality is important. Mechanical, or high-yield pulp, which is used to make newsprint, still contains most of the lignin originally present in the wood. This lignin is responsible for newsprint's yellowing with age. High quality paper requires the removal of lignin from the pulp. These delignification processes are core technologies of the papermaking industry as well as the source of significant environmental concerns. In sulfite pulping, lignin is removed from wood pulp as lignosulfonates, for which many applications have been proposed. They are used as dispersants, humectants, emulsion stabilizers, and sequestrants (water treatment). Lignosulfonate was also the first family of water reducers or superplasticizers to be added in the 1930s as admixture to fresh concrete in order to decrease the water-to-cement ("w/c") ratio, the main parameter controlling the concrete porosity, and thus its mechanical strength, its diffusivity and its hydraulic conductivity, all parameters essential for its durability. It has application in environmentally sustainable dust suppression agent for roads | https://en.wikipedia.org/wiki?curid=190996 | 26,895 |
Karl Jaspers " Jaspers is also indebted to his contemporaries, such as Heinrich Blücher from who he borrowed the term, "the anti-political principle" to describe totalitarianism's destruction of a space of resistance. | https://en.wikipedia.org/wiki?curid=332245 | 236,841 |
Ecology Natural historians, such as Humboldt, James Hutton, and Jean-Baptiste Lamarck (among others) laid the foundations of the modern ecological sciences. The term "ecology" () was coined by Ernst Haeckel in his book "Generelle Morphologie der Organismen" (1866). Haeckel was a zoologist, artist, writer, and later in life a professor of comparative anatomy. Opinions differ on who was the founder of modern ecological theory. Some mark Haeckel's definition as the beginning; others say it was Eugenius Warming with the writing of Oecology of Plants: An Introduction to the Study of Plant Communities (1895), or Carl Linnaeus' principles on the economy of nature that matured in the early 18th century. Linnaeus founded an early branch of ecology that he called the economy of nature. His works influenced Charles Darwin, who adopted Linnaeus' phrase on the "economy or polity of nature" in "The Origin of Species". Linnaeus was the first to frame the balance of nature as a testable hypothesis. Haeckel, who admired Darwin's work, defined ecology in reference to the economy of nature, which has led some to question whether ecology and the economy of nature are synonymous. From Aristotle until Darwin, the natural world was predominantly considered static and unchanging. Prior to "The Origin of Species", there was little appreciation or understanding of the dynamic and reciprocal relations between organisms, their adaptations, and the environment | https://en.wikipedia.org/wiki?curid=9630 | 189,889 |
Enhancer-FACS-seq Accelerating the annotation of the regulatory genome in Drosophila should in principle generate the kind of large-scale regulatory interaction data that would allow exploring the network properties of transcriptional regulation. | https://en.wikipedia.org/wiki?curid=44733611 | 79,845 |
Seaborgium at the Lawrence Livermore National Laboratory, a search for element 106 using oxygen-18 projectiles and the previously used californium-249 target was conducted. Several 9.1 MeV alpha decays were reported and are now thought to originate from element 106, though this was not confirmed at the time. In 1972, the HILAC accelerator received equipment upgrades, preventing the team from repeating the experiment, and data analysis was not done during the shutdown. This reaction was tried again several years later, in 1974, and the Berkeley team realized that their new data agreed with their 1971 data, to the astonishment of Ghiorso. Hence, element 106 could have actually been discovered in 1971 if the original data was analyzed more carefully. Two groups claimed discovery of the element. Unambiguous evidence of element 106 was first reported in 1974 by a Russian research team in Dubna led by Yuri Oganessian, in which targets of lead-208 and lead-207 were bombarded with accelerated ions of chromium-54. In total, fifty-one spontaneous fission events were observed with a half-life between four and ten milliseconds. After having ruled out nucleon transfer reactions as a cause for these activities, the team concluded that the most likely cause of the activities was the spontaneous fission of isotopes of element 106. The isotope in question was first suggested to be seaborgium-259, but was later corrected to seaborgium-260. A few months later in 1974, researchers including Glenn T | https://en.wikipedia.org/wiki?curid=28144 | 83,119 |
Geochemistry Those rocks that contain the most silica, and on crystallizing yield free quartz, form a group generally designated the "felsic" rocks. Those again that contain least silica and most magnesia and iron, so that quartz is absent while olivine is usually abundant, form the "mafic" group. The "intermediate" rocks include those characterized by the general absence of both quartz and olivine. An important subdivision of these contains a very high percentage of alkalis, especially soda, and consequently has minerals such as nepheline and leucite not common in other rocks. It is often separated from the others as the "alkali" or "soda" rocks, and there is a corresponding series of mafic rocks. Lastly a small sub-group rich in olivine and without feldspar has been called the "ultramafic" rocks. They have very low percentages of silica but much iron and magnesia. Except these last, practically all rocks contain felspars or feldspathoid minerals. In the acid rocks the common feldspars are orthoclase, perthite, microcline, and oligoclase—all having much silica and alkalis. In the mafic rocks labradorite, anorthite and bytownite prevail, being rich in lime and poor in silica, potash and soda. Augite is the most common ferro-magnesian in mafic rocks, but biotite and hornblende are on the whole more frequent in felsic rocks. Rocks that contain leucite or nepheline, either partly or a wholly replacing felspar, are not included in this table. They are essentially of intermediate or of mafic character | https://en.wikipedia.org/wiki?curid=39562 | 38,251 |
Octant (instrument) The only obvious difference is the presence of horizon shades on the Crichton octant that are not on the other. These octants were available with many options. A basic octant with graduations directly on the wood frame were least expensive. These dispensed with a telescopic sight, using a single- or double-holed sighting pinnula instead. Ivory scales would increase the price, as would the use of a brass index arm or a vernier. In 1767 the first edition of the Nautical Almanac tabulated lunar distances, enabling navigators to find the current time from the angle between the sun and the moon. This angle is sometimes larger than 90°, and thus not possible to measure with an octant. For that reason, Admiral John Campbell, who conducted shipboard experiments with the lunar distance method, suggested a larger instrument and the sextant was developed. From that time onward, the sextant was the instrument that experienced significant development and improvements and was the instrument of choice for naval navigators. The octant continued to be produced well into the 19th century, though it was generally a less accurate and less expensive instrument. The lower price of the octant, including versions without telescope, made it a practical instrument for ships in the merchant and fishing fleets. One common practice among navigators up to the late nineteenth century was to use both a sextant and an octant | https://en.wikipedia.org/wiki?curid=2592962 | 199,501 |
BELBIC One logic behind this use in control engineering is a belief held by many experts in the field that there has been too much focus on fully rational deliberative approaches, whereas in many real-world circumstances, we are only provided with a bounded rationality. Factors like computational complexity, multiplicity of objectives and prevalence of uncertainty lead to a desire to obtain more ad-hoc, rule-of-thumb approaches. Emotional decision making is highly capable of addressing these issues because it is neither fully cognitive nor fully behavioral. BELBIC, which is a model free controller, suffers from the same drawback of all intelligent model free controllers: it cannot be applied on unstable systems or systems with unstable equilibrium point. This is a natural result of the trial and error manner of the learning procedure, i.e. exploration for finding the appropriate control signals can lead to instability. By integrating imitative learning and fuzzy inference systems, is generalized in order to be capable of controlling unstable systems. To date, and its modified versions have been tested on the following applications: | https://en.wikipedia.org/wiki?curid=15497991 | 376,183 |
Regulation of genetic engineering The regulation of genetic engineering varies widely by country. Countries such as the United States, Canada, Lebanon and Egypt use "substantial equivalence" as the starting point when assessing safety, while many countries such as those in the European Union, Brazil and China authorize GMO cultivation on a case-by-case basis. Many countries allow the import of GM food with authorization, but either do not allow its cultivation (Russia, Norway, Israel) or have provisions for cultivation, but no GM products are yet produced (Japan, South Korea). Most countries that do not allow for GMO cultivation do permit research. Most (85%) of the world's GMO crops are grown in the Americas (North and South). One of the key issues concerning regulators is whether GM products should be labeled. Labeling of GMO products in the marketplace is required in 64 countries. Labeling can be mandatory up to a threshold GM content level (which varies between countries) or voluntary. A study investigating voluntary labeling in South Africa found that 31% of products labeled as GMO-free had a GM content above 1.0%. In Canada and the USA labeling of GM food is voluntary, while in Europe all food (including processed food) or feed which contains greater than 0.9% of approved GMOs must be labelled. There is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food, but that each GM food needs to be tested on a case-by-case basis before introduction | https://en.wikipedia.org/wiki?curid=31540040 | 272,751 |
Evasion (network security) discusses TCP/IP protocol exploits, evasions and others. More recent discussions on evasions include the report by Kevin Timm. The challenge in protecting servers from evasions is to model the end-host operation at the network security device, i.e., the device should be able to know how the target host would interpret the traffic, and if it would be harmful, or not. A key solution in protecting against evasions is traffic normalization at the IDS/IPS device. Lately there has been discussions on putting more effort on research in evasion techniques. A presentation at Hack.lu discussed some potentially new evasion techniques and how to apply multiple evasion techniques to by-pass network security devices. Singh, Abhishek. "Evasions In Intrusion Prevention Detection Systems". Virus Bulletin. Retrieved 1 April 2010. | https://en.wikipedia.org/wiki?curid=29068309 | 353,238 |
Rotating biological contactor As a result, the issue of short life failure became fully understood in the early 1990s when the correct process and hydraulic issues had been identified to produce a high quality nitrified effluent. There are several other papers which address the whole issue of RBCs. Findlay also developed a system for repairing defective RBCs enabling shaft and frame life to be extended up to 30 years based on the Cranfield designed frame. Where additional capacity was required intermediate frames are used maximising minimising the need for duplication Secondary clarifiers following RBCs are identical in design to conventional humus tanks, as used downstream of trickling filters. Sludge is generally removed daily, or pumped automatically to the primary settlement tank for co-settlement. Regular sludge removal reduces the risk of anaerobic conditions from developing within the sludge, with subsequent sludge flotation due to the release of gases. | https://en.wikipedia.org/wiki?curid=30862811 | 285,718 |
Informal economy The justifications for such criticisms include viewing the informal economy as a fraudulent activity that results in a loss of revenue from taxes, weakens unions, creates unfair competition, leads to a loss of regulatory control on the government's part, reduces observance of health and safety standards, and reduces the availability of employment benefits and rights. These characteristics have led to many nations pursuing a policy of deterrence with strict regulation and punitive procedures. In a 2004 report, the Department for Infrastructure and Economic Cooperation under SIDA explained three perspectives on the role of government and policy in relation to the informal economy. As informal economy has significant job creation and income generation potential, as well as the capacity to meet the needs of poor consumers by providing cheaper and more accessible goods and services, many stakeholders subscribe to the third perspective and support government intervention and accommodation. Embedded in the third perspective is the significant expectation that governments will revise policies that have favored the formal sphere at the expense of the informal sector. Theories of how to accommodate the informal economy argue for government policies that, recognizing the value and importance of the informal sector, regulate and restrict when necessary but generally work to improve working conditions and increase efficiency and production | https://en.wikipedia.org/wiki?curid=66499 | 507,156 |
Loudspeaker In the 1930s, loudspeaker manufacturers began to combine two and three bandpasses' worth of drivers in order to increase frequency response and sound pressure level. In 1937, the first film industry-standard loudspeaker system, "The Shearer Horn System for Theatres" (a two-way system), was introduced by Metro-Goldwyn-Mayer. It used four 15″ low-frequency drivers, a crossover network set for 375 Hz, and a single multi-cellular horn with two compression drivers providing the high frequencies. John Kenneth Hilliard, James Bullough Lansing, and Douglas Shearer all played roles in creating the system. At the 1939 New York World's Fair, a very large two-way public address system was mounted on a tower at Flushing Meadows. The eight 27″ low-frequency drivers were designed by Rudy Bozak in his role as chief engineer for Cinaudagraph. High-frequency drivers were likely made by Western Electric. Altec Lansing introduced the "604", which became their most famous coaxial Duplex driver, in 1943. It incorporated a high-frequency horn that sent sound through a hole in the pole piece of a 15-inch woofer for near-point-source performance. Altec's "Voice of the Theatre" loudspeaker system was first sold in 1945, offering better coherence and clarity at the high output levels necessary in movie theaters. The Academy of Motion Picture Arts and Sciences immediately began testing its sonic characteristics; they made it the film house industry standard in 1955 | https://en.wikipedia.org/wiki?curid=45871 | 304,534 |
Wavelet In particular, assuming a rectangular window region, one may think of the STFT as a transform with a slightly different kernel where formula_38 can often be written as formula_39, where formula_40 and u respectively denote the length and temporal offset of the windowing function. Using Parseval's theorem, one may define the wavelet's energy as From this, the square of the temporal support of the window offset by time u is given by and the square of the spectral support of the window acting on a frequency formula_43 Multiplication with a rectangular window in the time domain corresponds to convolution with a formula_45 function in the frequency domain, resulting in spurious ringing artifacts for short/localized temporal windows. With the continuous-time Fourier Transform, formula_46 and this convolution is with a delta function in Fourier space, resulting in the true Fourier transform of the signal formula_47. The window function may be some other apodizing filter, such as a Gaussian. The choice of windowing function will affect the approximation error relative to the true Fourier transform. A given resolution cell's time-bandwidth product may not be exceeded with the STFT. All STFT basis elements maintain a uniform spectral and temporal support for all temporal shifts or offsets, thereby attaining an equal resolution in time for lower and higher frequencies. The resolution is purely determined by the sampling width | https://en.wikipedia.org/wiki?curid=50903 | 115,829 |
Two-photon excitation microscopy These techniques use focused laser beams scanned in a raster pattern to generate images, and both have an optical sectioning effect. Unlike confocal microscopes, multiphoton microscopes do not contain pinhole apertures that give confocal microscopes their optical sectioning quality. The optical sectioning produced by multiphoton microscopes is a result of the point spread function of the excitation: the multiphoton point spread function is typically dumbbell-shaped (longer in the x-y plane), compared to the upright rugby-ball shaped point spread function of confocal microscopes. The concept of two-photon excitation is based on the idea that two photons, of comparably lower photon energy than needed for one photon excitation, can also excite a fluorophore in one quantum event. Each photon carries approximately half the energy necessary to excite the molecule. Excitation results in the subsequent emission of a fluorescence photon with the same quantum yield that would result from conventional single-photon absorption. The emitted photon is typically at a higher energy (shorter wavelength) than either of the two exciting photons. The probability of the near-simultaneous absorption of two photons is extremely low. Therefore, a high peak flux of excitation photons is typically required, usually generated by femtosecond pulsed laser. The purpose of employing the two-photon effect is that the axial spread of the point spread function is substantially lower than for single-photon excitation | https://en.wikipedia.org/wiki?curid=2105059 | 67,117 |
Medical applications of radio frequency (RF) energy, in the form of electromagnetic waves (radio waves) or electrical currents, have existed for over 125 years, and now include diathermy, hyperthermy treatment of cancer, electrosurgery scalpels used to cut and cauterize in operations, and radiofrequency ablation. Magnetic resonance imaging (MRI) uses radio frequency waves to generate images of the human body. Radio frequencies at non-ablation energy levels are commonly used as a part of aesthetic treatments that can tighten skin, reduce fat by lipolysis and also apoptosis, or promote healing. RF diathermy is a medical treatment that uses RF induced heat as a form of physical therapy and in surgical procedures. It is commonly used for muscle relaxation. It is also a method of heating tissue electromagnetically for therapeutic purposes in medicine. Diathermy is used in physical therapy to deliver moderate heat directly to pathologic lesions in the deeper tissues of the body. Surgically, the extreme heat that can be produced by diathermy may be used to destroy neoplasms, warts, and infected tissues, and to cauterize blood vessels to prevent excessive bleeding. The technique is particularly valuable in neurosurgery and surgery of the eye. Diathermy equipment typically operates in the short-wave radio frequency (range 1–100 MHz) or microwave energy (range 434–915 MHz). Pulsed electromagnetic field therapy (PEMF) is a medical treatment that purportedly helps to heal bone tissue reported in a recent NASA study | https://en.wikipedia.org/wiki?curid=60039992 | 386,913 |
Orion Pictures Republic Pictures and the then-new Savoy Pictures also attempted to buy Orion, but no deal materialized. At the Academy Awards ceremony, broadcast on March 30, 1992, Crystal made another reference to Orion, this time about its demise: "The Silence of the Lambs" swept all five major Academy Awards; however, a majority of key executives, as well as the talent they had deals with, had left the studio. Hollywood observers had doubts that Orion would be resurrected to its former glory. On November 5, 1992, Orion reemerged from bankruptcy. Its reorganization plan would allow for Orion to continue producing and releasing films, but financing for the features would be provided by outside sources, with the studio purchasing the distribution rights to them after their completion. Orion's bankruptcy also delayed the release of many films the studio had produced or acquired, among them: "Love Field" (1992), "RoboCop 3" (1993), "The Dark Half" (1993), "Blue Sky" (1994), "Car 54, Where Are You?" (1994), "Clifford" (1994), "The Favor" (1994), and "There Goes My Baby" (1994). Orion started releasing these films after their reorganization. "Blue Sky" won star Jessica Lange an Academy Award for Best Actress in 1995. In November 1995, Orion, two other companies controlled by Kluge, and film and TV house MCEG Sterling (producer of the "Look Who's Talking" series) were merged to form the Metromedia International Group | https://en.wikipedia.org/wiki?curid=218723 | 500,163 |
Quality-adjusted life year The researchers asked the subjects to respond to 14 questions concerning their preferences for various health states and durations of those states (e.g., 15 years limping versus 5 years in a wheelchair). They concluded that "preferences expressed by the respondents were not consistent with the QALY theoretical assumptions" that quality of life can be measured in consistent intervals, that life-years and quality of life are independent of each other, that people are neutral about risk, and that willingness to gain or lose life-years is constant over time. ECHOUTCOME also released "European Guidelines for Cost-Effectiveness Assessments of Health Technologies," which recommended not using QALYs in healthcare decision making. Instead, the guidelines recommended that cost-effectiveness analyses focus on "costs per relevant clinical outcome." In response to the ECHOUTCOME study, representatives of the National Institute for Health and Care Excellence, the Scottish Medicines Consortium, and the Organisation for Economic Co-operation and Development made the following points. First, QALYs are better than alternative measures. Second, the study was "limited." Third, problems with QALYs were already widely acknowledged. Fourth, the researchers did not take budgetary constraints into consideration. Fifth, the UK's National Institute for Health and Care Excellence uses QALYs that are based on 3395 interviews with residents of the UK, as opposed to residents of several European countries | https://en.wikipedia.org/wiki?curid=1393169 | 457,461 |
Josie and the Pussycats (film) Josie and the Pussycats is a 2001 musical comedy film released by Metro-Goldwyn-Mayer and Universal Pictures. Directed and co-written by Harry Elfont and Deborah Kaplan, the film is loosely based on the Archie Comics series and the Hanna-Barbera cartoon of the same name. The film stars Rachael Leigh Cook, Tara Reid, and Rosario Dawson as the Pussycats, with Alan Cumming, Parker Posey, Gabriel Mann, Paulo Costanzo, and Missi Pyle in supporting roles. The film received mixed reviews and was a box office bomb upon its initial release, but has enjoyed later success as a cult film. Wyatt Frame (Alan Cumming), an executive with the pop music record label MegaRecords, is confronted on a private jet by successful boy band DuJour over a strange backing track they have discovered on their recent single. Wyatt and the plane's pilot parachute out of the jet, leaving it to crash with the band still on board. Wyatt lands outside of the town of Riverdale, and he begins searching for a band to replace DuJour. He discovers struggling local rock band The Pussycats: lead vocalist and guitarist Josie McCoy (Rachael Leigh Cook), drummer Melody Valentine (Tara Reid), and bassist Valerie Brown (Rosario Dawson). The group accept Wyatt's immediate offer of a major record deal despite its seeming implausibility, and they are flown to New York City with their manager Alexander (Paul Costanzo), his sister Alexandra (Missi Pyle), and Josie's friend Alan M (Gabriel Mann) | https://en.wikipedia.org/wiki?curid=754323 | 476,581 |
Economizer It also allows maximum heat exchanger use as minimizes the portion of the heat exchangers used to change the temperature of the fluid, and maximizes the volume in which the refrigerant changes its phase (phenomena involving much more heat flow, the base principle of vapor-compression refrigeration). An internal heat exchanger is simply a type of heat exchanger that uses the cold gas leaving the evaporator coil to cool the high-pressure liquid that is headed into the beginning of the evaporator coil via an expansion device. The gas is used to chill a chamber that normally has a series of pipes for the liquid running through it. The superheated gas then proceeds on to the compressor. The subcooling term refers to cooling the liquid below its boiling point. of subcooling means it is 10 °F colder than boiling at a given pressure. As it represents a difference of temperatures, the subcooling value won't change if it is measured on the absolute scale, or the relative scale (10 °F of subcooling equals of subcooling). | https://en.wikipedia.org/wiki?curid=4655742 | 424,266 |
Network analyzer (AC power) The Westinghouse network analyzer purchased by the State Electricity Commission of Victoria, Australia in 1950 was taken out of utility service in 1967 and donated to the Engineering department at Monash University; but by 1985, even instructional use of the analyzer was no longer practical and the system was finally dismantled. One factor contributing to the obsolescence of analog models was the increasing complexity of interconnected power systems. Even a large analyzer could only represent a few machines, and perhaps a few score lines and busses. Digital computers routinely handled systems with thousands of busses and transmission lines. | https://en.wikipedia.org/wiki?curid=38433617 | 221,585 |
Microwave imaging FMCW is advantageous to determine the depth of defects within the DUT. A test probe attached to the DUT's surface gives information about the material distribution below the point of contact. When moving over the DUT surface point by point many such information is stored and then evaluated to give an overall image. This takes time. Directly imaging procedures are faster: Microwave versions are either electronic or make use of planar microwave detector consisting of a microwave absorbing foil and an infrared camera (NIDIT procedure). Microwave testing is a useful NDT method for dielectric materials. Among them are plastics, glass-fiber reinforced plastics (GFRP), plastic foams, wood, wood-plastic composites (WPC), and most types of ceramics. Defects interior in the DUT and at its surface can be detected, e. g. in semi-finished products or pipes. "Special applications" of microwave testing are non-destructive Microwave testing is used in many industrial sectors: In the last years the need for NDT has increased generally and especially also for dielectric materials. For this reason and because microwave technics more and more are used in consumer products and hereby became much less expensive, NDT with microwaves increases. In recognizing this growing importance, in 2011 the "Expert committee for microwave and THz procedures" of the German Society of Non-Destructive Testing (DGZfP) was founded as in 2014 the "Microwave Testing Committee" of the American Society for Non-Destructive Testing (ASNT) | https://en.wikipedia.org/wiki?curid=42691862 | 224,801 |
Technician fifth grade (abbreviated as T/5 or TEC 5) was a United States Army technician rank during World War II. Those who held this rank were addressed as corporal, though were often called a "tech corporal". Technicians possessed specialized skills that were rewarded with a higher pay grade, but had no command authority. The pay grade number corresponded with the technician's rank. T/5 was under the pay grade 5, along with corporal. Technicians were easily distinguished by the "T" imprinted on the standard chevron design for that pay grade. The technician ranks were removed from the U.S. Army rank system in 1948, though the concept was brought back with the Specialist ranks in 1955. | https://en.wikipedia.org/wiki?curid=6769186 | 212,933 |
Thunderbolt (interface) Thunderbolt is the brand name of a hardware interface developed by Intel (in collaboration with Apple) that allows the connection of external peripherals to a computer. Thunderbolt 1 and 2 use the same connector as Mini DisplayPort (MDP), whereas Thunderbolt 3 re-uses the USB-C connector from USB. It was initially developed and marketed under the name Light Peak, and first sold as part of a consumer product on 24 February 2011. Thunderbolt combines PCI Express (PCIe) and DisplayPort (DP) into two serial signals, and additionally provides DC power, all in one cable. Up to six peripherals may be supported by one connector through various topologies. Thunderbolt controllers multiplex one or more individual data lanes from connected PCIe and DisplayPort devices for transmission via two duplex Thunderbolt lanes, then de-multiplex them for use by PCIe and DisplayPort devices on the other end. A single Thunderbolt port supports up to six Thunderbolt devices via hubs or daisy chains; as many of these as the host has DP sources may be Thunderbolt monitors. A single Mini DisplayPort monitor or other device of any kind may be connected directly or at the very end of the chain. Thunderbolt is interoperable with DP-1.1a compatible devices. When connected to a DP-compatible device, the Thunderbolt port can provide a native DisplayPort signal with four lanes of output data at no more than 5.4 Gbit/s per Thunderbolt lane | https://en.wikipedia.org/wiki?curid=24484686 | 377,578 |
Karl Popper Bartley III tried to radicalise this idea and made the controversial claim that not only can criticism go beyond empirical knowledge, but that everything can be rationally criticised. To Popper, who was an anti-justificationist, traditional philosophy is misled by the false principle of sufficient reason. He thinks that no assumption can ever be or needs ever to be justified, so a lack of justification is not a justification for doubt. Instead, theories should be tested and scrutinised. It is not the goal to bless theories with claims of certainty or justification, but to eliminate errors in them. He writes, Popper's principle of falsifiability runs into "prima facie" difficulties when the epistemological status of mathematics is considered. It is difficult to conceive how simple statements of arithmetic, such as "2 + 2 = 4", could ever be shown to be false. If they are not open to falsification they can not be scientific. If they are not scientific, it needs to be explained how they can be informative about real world objects and events. Popper's solution was an original contribution in the philosophy of mathematics. His idea was that a number statement such as "2 apples + 2 apples = 4 apples" can be taken in two senses. In one sense it is irrefutable and logically true, in the second sense it is factually true and falsifiable. Concisely, the pure mathematics "2 + 2 = 4" is always true, but, when the formula is applied to real-world apples, it is open to falsification | https://en.wikipedia.org/wiki?curid=16623 | 515,905 |
SPINE (molecular biology) SPINE stands for strep–protein interaction experiment. SPINE is a powerful tool to detect protein–protein interactions in vivo. The bait protein has to be expressed with a Strep-tag under the conditions when the potential interaction partners are presumably present in the cells. The addition of formaldehyde links the bait protein to its potential interaction partners. The bait protein together with its potential interaction partners can then be isolated using a Streptactin sepharose column. The cross-links between the bait protein and the potential interaction partner can be cleaved by heating the samples in Laemmli buffer. Finally, the co-purified interaction partner can be separated by SDS PAGE and identified by mass spectrometry. | https://en.wikipedia.org/wiki?curid=15768383 | 51,183 |
Hyperloop pod competition " Best Overall Subsystem Award: Auburn University Hyperloop Team, Auburn University; Safety Subsystem Technical Excellence Award: UWashington Hyperloop, University of Washington; Special Innovation Award in the Other Subsystem: RIT Imaging, Rochester Institute of Technology; :Levitation Subsystem Technical Excellence Award: TAMU Aerospace Hyperloop, Texas A&M; Braking Subsystem Technical Excellence Award: VicHyper, RMIT University; Propulsion/Compression Subsystem Technical Excellence Award: Makers UPV Team, Universitat Politècnica de València; Subsystem Technical Excellence Awards: Hyped, University of Edinburgh; Conant Hyperloop Club, Conant High School; Subsystem Innovation Award: Ryerson's International Hyperloop Team, Ryerson University. Top Design Concept Award: Makers UPV Team (see above); Design Concept Innovation Award: Nova Hyperloop Team, University of Cairo; Design Concept Innovation Award: Auburn University Hyperloop Team (see above). Phase 2 of the competition ran 27–29 January 2017 after previously being planned for as early as August 2016. 27 teams competed in two overall categories and five subcategories. Each pod in the competition needed to progress through ten sequential tests, only the last of which would be a vacuum-environment speed run in the mile-long Hypertube. Problems with dust and misalignment of the track limited performance and caused widespread problems | https://en.wikipedia.org/wiki?curid=49273370 | 214,300 |
Witches' Well, Edinburgh The Witches' Well is a monument to accused witches burned at the stake in Edinburgh, Scotland, and is the only one of its kind in the city. The memorial drinking fountain is attached to a wall at the lower end of the Castle Esplanade, below Edinburgh Castle, and located close to where many witches were burned at the stake. During the high point of witch hunting in the early modern period, 32% of accused witches came from the Lothian area. The well was commissioned by Sir Patrick Geddes in 1894, and designed by Geddes' friend John Duncan. The bronze relief features a foxglove plant, a snake curled around the heads of Hygeia, the Greek goddess of good health, and her father Aesculapius, god of medicine. Other parts of the well feature trees, healing hands, and the evil eye. The water spout, now dry, is located beneath the snake's head. In the top left and bottom right are the Roman numerals for the years 1479 and 1722 respectively, the time period during which most witches were persecuted in Scotland. The model for the Well is held by the City Art Centre in Edinburgh. The building upon which it is affixed (now containing the Tartan Weaving Mill) was built in 1851, for the Castlehill Reservoir. The 1851 building replaced its 17th-century predecessor, constructed when act of parliament in 1624 enabled the bringing of fresh water into the city from the nearby Pentland Hills. In 1674 the reservoir was connected to 12 wells around the city, eventually closing in 1992, and converted into the Tartan Mill in 1996 | https://en.wikipedia.org/wiki?curid=62077301 | 351,430 |
Lead Books of Sacromonte Both Castillo and Luna escaped the expulsion, as the archbishop of Granada, Pedro de Vaca de Castro y Quiñones, grateful for the immense increase in the prestige of his see arising from the discovery of the relics of St Caecilius, extended his personal protection to them and their families. Many of the deported Moriscos remained convinced of the books' authenticity however, and transcripts continued to circulate within Tunisia, until this practice was forcibly suppressed by Islamic religious authorities there. The authenticity of the bones and ashes of the 12 martyrs was never officially challenged, and they continue to be venerated in the Abbey that Archbishop Castro built on the spot. Hence the legend has acquired a moral function directly contrary to the intention of its presumed original propagators; far from validating the authentically Spanish identity of Granada's Morisco traditions, the legend has served to sanction and celebrate the supersession of those traditions. | https://en.wikipedia.org/wiki?curid=19193869 | 63,339 |
Dunning–Kruger effect To do so, they employed different kinds of graphics that suppress or eliminate the noise responsible for most of the artifacts and distortions. The authors discovered that the different graphics refuted the assertions made for the Effect. Instead, they showed that most people are reasonably accurate in their self-assessments. About half of the 1154 participants in their studies accurately estimated their performance within ±10 percentage points (ppts). Two-thirds of these participants self-assessed their competency scores within ±15 ppts. Only about 6% of participants displayed wild overconfidence and were unable to accurately self-assess their abilities within 30 ppts. All groups overestimated and underestimated their actual ability with equal frequency. No marked tendency toward overconfidence, as predicted by the Effect, occurs, even in the most novice groups. In 2020, with an updated database of over 5000 participants, this relationship still held true. The revised mathematical interpretation of data confirmed that people typically have no pronounced tendency to overestimate their actual proficiency. Groups' mean self-assessments prove more than an order of magnitude more accurate than do individuals'. In randomly selected groups of 50 participants, 81% of groups' self-assessed mean scores were within 3 ppts of their actual mean competency score | https://en.wikipedia.org/wiki?curid=2288777 | 482,597 |
Criticisms of Sky UK Although the bid was "dropped after only five weeks" some media commentators presumed it had been done to "bide time" and that News Corp were "still confident" they could prove their bid was not "a serious threat to competition". In October 2010, a group of media companies – accounting for a third of Fleet Street and the BBC – jointly wrote to Vince Cable, the Business Secretary, to lay out their reasons for the BSkyB share bid being a breach of media plurality. The BBC's contribution to the letter was subsequently attacked in a (News International owned) Times editorial. Ofcom complained that Sky's plan to operate pay TV services on Freeview was "generating serious consumer detriment" and the National Consumer Council call Sky's plan "bad news for consumers," combined with representations from BT, Setanta, Top Up TV, and Virgin Media caused Ofcom to launch an investigation into the "features of the [UK pay TV] market, including control over content, ownership of distribution platforms, retail subscriber bases and vertical integration." Sky repeatedly used its lawyers to lodge complaints with the soon-to-be-rival YouView service, considered by some to be a delaying tactic in order to promote its own services, especially considering its failure to complain about other services, such as Google TV | https://en.wikipedia.org/wiki?curid=28906679 | 485,907 |
Corona radiata (embryology) The corona radiata is the innermost layer of the cells of the cumulus oophorus and is directly adjacent to the zona pellucida, the inner protective glycoprotein layer of the ovum. Its main purpose in many animals is to supply vital proteins to the cell. It is formed by follicle cells adhering to the oocyte before it leaves the ovarian follicle, and originates from the squamous granulosa cells present at the primordial stage of follicular development. The corona radiata is formed when the granulosa cells enlarge and become cuboidal, which occurs during the transition from the primordial to primary stage. These cuboidal granulosa cells, also known as the granulosa radiata, form more layers throughout the maturation process, and remain attached to the zona pellucida after the ovulation of the Graafian follicle. For fertilization to occur, sperm cells rely on hyaluronidase (an enzyme found in the acrosome of spermatozoa) to disperse the corona radiata from the zona pellucida of the secondary (ovulated) oocyte, thus permitting entry into the perivitelline space and allowing contact between the sperm cell and the nucleus of the oocyte. | https://en.wikipedia.org/wiki?curid=4249362 | 151,511 |
TSheets It also features an open API — allowing developers to merge with their existing applications and software (if no integration exists). has received press in the technology and business sectors, including an interview with CEO Matt Rissell in Fast Company’s WorkFast TV series, and mentions in Inc. and TechCrunch, republished in the Washington Post. has also appeared in Business 2 Community, Idaho Business Review, and the WSJ among several other news and online technology sources. | https://en.wikipedia.org/wiki?curid=32166425 | 486,851 |
Photogeochemistry At the same time, many other workers reported negative results. One of the pioneer experiments was that of Bach in 1893, who observed the formation of lower uranium oxides upon irradiation of a solution of uranium acetate and carbon dioxide, implying the formation of formaldehyde. Some experiments included reducing agents such as hydrogen gas, and others detected formaldeyhde or other products in the absence of any additives, although the possibility was admitted that reducing power may have been produced from the decomposition of water during the experiment. In addition to the main focus on synthesis of formaldehyde and simple sugars, other light-assisted reactions were occasionally reported, such as the decomposition of formaldehyde and subsequent release of methane, or the formation of formamide from carbon monoxide and ammonia. In 1912 Benjamin Moore summarized the main facet of photogeochemistry, that of inorganic photocatalysis: "the inorganic colloid must possess the property of transforming sunlight, or some other form of radiant energy, into chemical energy." Many experiments, still focused on how plants assimilate carbon, did indeed explore the effect of a "transformer" (catalyst); some effective "transformers" were similar to naturally occurring minerals, including iron(III) oxide or colloidal iron hydroxide; cobalt carbonate, copper carbonate, nickel carbonate; and iron(II) carbonate | https://en.wikipedia.org/wiki?curid=47664587 | 46,025 |
Sensory loss It also comprises essential processing centres, or sensory modalities, such as proprioception, touch, temperature, and nociception. The sensory receptors cover the skin and epithelia, skeletal muscles, bones and joints, internal organs, and the cardiovascular system. While touch (also called tactile or tactual perception) is considered one of the five traditional senses, the impression of touch is formed from several modalities. In medicine, the colloquial term "touch" is usually replaced with "somatic senses" to better reflect the variety of mechanisms involved. Insensitivity to somatosensory stimuli, such as heat, cold, touch, and pain, are most commonly a result of a more general physical impairment associated with paralysis. Damage to the spinal cord or other major nerve fiber may lead to a termination of both afferent and efferent signals to varying areas of the body, causing both a loss of touch and a loss of motor coordination. Other types of somatosensory loss include hereditary sensory and autonomic neuropathy, which consists of ineffective afferent neurons with fully functioning efferent neurons; essentially, motor movement without somatosensation. can occur due to a minor nick or lesion on the spinal cord which creates a problem within the neurosystem. This can lead to loss of smell, taste, touch, sight, and hearing. In most cases it often leads to issues with touch. Sometimes people cannot feel touch at all while other times a light finger tap feels like someone has punched them | https://en.wikipedia.org/wiki?curid=29018856 | 178,002 |
Microraft A (Isoraft) is an arrays of microwells for cell sorting, isolating cells, analyzing cells over time, and generating clonal populations. This platform provides biomedical scientists with access to diverse cell culture surfaces with integrated, easy-to-use cell separating capabilities at low cost. The microrafts have bases composed of detachable concave elements fabricated by a dip-coating process using a polydimethylsiloxane mold as the template and the array substrate. This manufacturing approach allows the microrafts to possess low autofluorescence and can therefore be utilized for fluorescence-based identification of cells. Cells plated on the microarray settle and attach at the center of the wells due to the microrafts’ concavity. Individual microrafts are dislodged using a needle inserted through the compliant polymer substrate. The hard polymer material of the microrafts protect the cells from damage by the needle. Cell analysis and isolation can be carried out using a standard inverted microscope. Released cells/microrafts can be collected, cultured and clonally expanded. Using this system, extremely high single-cell cloning rates of greater than 95% have been achieved. This system is ideal for both adherent and non-adherent cell types. | https://en.wikipedia.org/wiki?curid=38939487 | 271,844 |
Autophosphorylation The known structures include: In general, the structures of the phosphorylation of internal loops involve important domain-domain contacts that have been confirmed by site-directed mutagenesis, while the phosphorylation of positions in the N or C terminal tails more than 10 amino acids away from the kinase domain do not involve important domain-domain contacts away from the substrate binding site. Among a number of various molecules, Receptor Tyrosine Kinases (RTKs ) play a critical role in transducing signals through a range of signaling pathways. All RTKs consists of an extracellular ligand binding region, a single transmembrane helix and a cytoplasmic region (the tyrosine kinase domain). Prior to ligand stimulation most RTKs present as a monomer on the surface of cells. Ligand binding to the extracellular domain induces dimerization. Dimerization of RTKs leads to autophosphorylation of tyrosine in the catalytic core of the dimer, and finally stimulation of the tyrosine kinase activity and cell signaling. It is thus an example of a trans-autophosphorylation reaction, where one receptor subunit of the dimer phosphorylates the other subunit. An example of RTKs that undergo autophosphorylation is the Epidermal Growth Factor receptor (EGFR ). EGFR was the first discovered example of RTKs. Following ligand binding, a conformational change occurs in the EGFR monomers. This leads to EGFR dimerization. Dimerization brings the two receptors into close proximity | https://en.wikipedia.org/wiki?curid=33838036 | 61,660 |
Martin Khor His wake was held at the funeral parlor at Mount Erskine on the following day and his funeral was held on April 2nd at the same location. He had a daughter and a wife at the time of his death and Datuk Seri Mohamad Hasan paid tribute to him. WSF 2003 Scenarios for the future | https://en.wikipedia.org/wiki?curid=2960328 | 513,900 |
Seismic magnitude scales This is especially useful for measuring local or regional earthquakes, both powerful earthquakes that might drive the seismometer off-scale (a problem with the analog instruments formerly used) and preventing measurement of the maximum wave amplitude, and weak earthquakes, whose maximum amplitude is not accurately measured. Even for distant earthquakes, measuring the duration of the shaking (as well as the amplitude) provides a better measure of the earthquake's total energy. Measurement of duration is incorporated in some modern scales, such as and . M scales usually measure the duration or amplitude of a part of the seismic wave, the "coda". For short distances (less than ~100 km) these can provide a quick estimate of magnitude before the quake's exact location is known. Magnitude scales generally are based on instrumental measurement of some aspect of the seismic wave as recorded on a seismogram. Where such records do not exist, magnitudes can be estimated from reports of the macroseismic events such as described by intensity scales. One approach for doing this (developed by Beno Gutenberg and Charles Richter in 1942) relates the maximum intensity observed (presumably this is over the epicenter), denoted "I" (capital I with a subscripted zero), to the magnitude. It has been recommended that magnitudes calculated on this basis be labeled "M(I)", but are sometimes labeled with a more generic M. Another approach is to make an "isoseismal map" showing the area over which a given level of intensity was felt | https://en.wikipedia.org/wiki?curid=6207163 | 331,272 |
Thermoelectric cooling formula_1 There are few materials that are suitable for TEC applications since the relationship between thermal and electrical conductivity is usually a positive correlation. Improvements in reduced thermal transport with increased electrical conductivity are an active area of material science research. Common thermoelectric materials used as semiconductors include bismuth telluride, lead telluride, silicon germanium, and bismuth-antimony alloys. Of these bismuth telluride is the most commonly used. New high-performance materials for thermoelectric cooling are being actively researched. The working elements must be in an isolated casing, and the best geometry is a plane. Usually this will be them being sandwiched between a pair of ceramic plaques, sealed (or not). The vast majority of thermoelectric coolers have an ID printed on the cooled side. These universal IDs clearly indicate the size, number of stages, number of couples, and current rating in amps, as seen in the adjacent diagram. Very common Tec1-12706, square of 40 millimeters size and 3-4 mm high, are found for a few dollars, and sold as able to move around 60W or generate a 60°C temperature difference with a 6 Amp current. Their electrical resistance will be of 1-2 ohm magnitude. There are many factors motivating further research on TEC including lower carbon emissions and ease of manufacturing. However, several challenges have arisen. A significant benefit of TEC systems is that they have no moving parts | https://en.wikipedia.org/wiki?curid=310597 | 449,796 |
Breathing gas The tissues and organs within the body (notably the heart and brain) are damaged if deprived of oxygen for much longer than four minutes. Filling a diving cylinder with pure oxygen costs around five times more than filling it with compressed air. As oxygen supports combustion and causes rust in diving cylinders, it should be handled with caution when gas blending. Oxygen has historically been obtained by fractional distillation of liquid air, but is increasingly obtained by non-cryogenic technologies such as pressure swing adsorption (PSA) and vacuum swing adsorption (VSA) technologies. The fraction of the oxygen component of a breathing gas mixture is sometimes used when naming the mix: The fraction of the oxygen determines the greatest depth at which the mixture can safely be used to avoid oxygen toxicity. This depth is called the maximum operating depth. The concentration of oxygen in a gas mix depends on the fraction and the pressure of the mixture. It is expressed by the partial pressure of oxygen (P). The partial pressure of any component gas in a mixture is calculated as: For the oxygen component, where: The minimum safe partial pressure of oxygen in a breathing gas is commonly held to be 16 kPa (0.16 bar). Below this partial pressure the diver may be at risk of unconsciousness and death due to hypoxia, depending on factors including individual physiology and level of exertion. When a hypoxic mix is breathed in shallow water it may not have a high enough P to keep the diver conscious | https://en.wikipedia.org/wiki?curid=459471 | 68,582 |
Biosynthesis of doxorubicin Dnr P, rhodomycin D methylesterase, removes the methyl group added previously by DnrC. It initially served to activate the adjacent methylene bridge, and after that it prevented its carboxyl group from leaving the C-10 carbon (see Fig 2). Had the carboxyl group not been esterified prior to the fourth ring cyclization, its departure as [ CO2 would have been favored by the formation of a bicyclic aromatic system. After C-7 reduction and glycosylation, the C-8 methylene bridge is no longer activated for deprotonation, thereby making aromatization less likely. Note that the non-isolable intermediate, with numbering, is the 3rd molecule in Figure 2. The numbering system is very odd and a vestige of early nomenclature. The decarboxylation of the intermediate occurs spontaneously, or by the influence of Dnr P, giving 13-deoxycarminomycin. A crystal structure, with bound products, of aclacinomycin methylesterase, an [enzyme] with 53% sequence homology to Dnr P, from "streptomyces purpurascens", has been solved. It is able to catalyze the same reaction and uses a classic Ser-His-Asp catalytic triad with serine acting as the nucleophile and gly-met providing stabilization of the transition state by forming an "oxyanion hole". The active site amino acids are almost entirely the same as Dnr P, and the mechanism is almost certainly identical | https://en.wikipedia.org/wiki?curid=12804558 | 89,584 |
Downregulation and upregulation In the biological context of organisms' production of gene products, downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus. The complementary process that involves increases of such components is called upregulation. An example of downregulation is the cellular decrease in the expression of a specific receptor in response to its increased activation by a molecule, such as a hormone or neurotransmitter, which reduces the cell's sensitivity to the molecule. This is an example of a locally acting (negative feedback) mechanism. An example of upregulation is the response of liver cells exposed to such xenobiotic molecules as dioxin. In this situation, the cells increase their production of cytochrome P450 enzymes, which in turn increases degradation of these molecules. Downregulation or upregulation of an RNA or protein may also arise by an epigenetic alteration. An epigenetic alteration can be permanent or semi-permanent in a somatic cell lineage. Such an epigenetic alteration can cause expression of the RNA or protein to no longer respond to an external stimulus. This occurs, for instance, during drug addiction or progression to cancer. All living cells have the ability to receive and process signals that originate outside their membranes, which they do by means of proteins called receptors, often located at the cell's surface imbedded in the plasma membrane | https://en.wikipedia.org/wiki?curid=1197980 | 50,979 |
Dragon King Theory In an adaptive system, where prediction of dragon kings is successful, one can act to defend the system or even profit. How to design such resilient systems, as well as their real time risk monitoring systems , is an important and interdisciplinary problem where dragon kings must be considered. On another note, when it comes to the quantification of risk in a given system (whether it be a bank, an insurance company, a dike, a bridge, or a socio-economic system), risk needs to be accounted for over a period, such as annually. Typically one is interested in statistics such as the annual probability of loss or damage in excess of some value (Value at risk), other tail risk measures, and return periods. To provide such risk characterizations, the dynamic dragon kings must be reasoned about in terms of annual frequency and severity statistics. These frequency and severity statistics can then be brought together in a model such as a Compound Poisson Process. Provided that the statistical properties of the system are consistent over time (stationary), frequency and severity statistics may be constructed based on past observations, simulations, and/or assumptions. If not, one may only construct scenarios. However, in any case, given the uncertainty present, a range of scenarios should be considered. Due to the shortage of data for extreme events, the principle of parsimony, and theoretical results from extreme value theory about universal tail models, one typically relies on a GPD tail model | https://en.wikipedia.org/wiki?curid=48403381 | 432,443 |
Distributed workforce Today, the new economy is characterized by an increasing virtualization of products, processes, organizations and relationships. The new economy production no longer requires people to work together in the same physical space to access the tools and resources they need to produce their work and allows for distributed work. After reviewing the chapter "Trust and Control in the Hudson's Bay Company in the book "Distributed Work", distributed work has been studied throughout history and not simply since the middle of the 1900s. Between 1670 and 1826, management had to rely on trust and control to successfully manage distributed work. During this time, in addition to dispersed operations that relied heavily on a combination of explicit information and detailed record keeping, more tacit and situated knowledge developed through socialization and participating in life on the Bay. The Hudson's Bay Company case of distributed work showed a variety of control mechanisms including selection techniques, information requirements, and direct local oversight through its distributed practices of socialization, communication, and participation. For example, the elaboration of reporting requirements during the period of inland expansion were used to supplement the current knowledge. A final aspect to note from the HBC case is the senior managements early learning about the strengths and weaknesses of contracts as a means of controlling distant agents | https://en.wikipedia.org/wiki?curid=21270193 | 451,485 |
Lean software development People might be resources from the point of view of a statistical data sheet, but in software development, as well as any organizational business, people do need something more than just the list of tasks and the assurance that they will not be disturbed during the completion of the tasks. People need motivation and a higher purpose to work for – purpose within the reachable reality, with the assurance that the team might choose its own commitments. The developers should be given access to the customer; the team leader should provide support and help in difficult situations, as well as ensure that skepticism does not ruin the team’s spirit. Respecting people and acknowledging their work is one way to empower the team. The customer needs to have an overall experience of the System. This is the so-called perceived integrity: how it is being advertised, delivered, deployed, accessed, how intuitive its use is, its price and how well it solves problems. Conceptual integrity means that the system’s separate components work well together as a whole with balance between flexibility, maintainability, efficiency, and responsiveness. This could be achieved by understanding the problem domain and solving it at the same time, not sequentially. The needed information is received in small batch pieces – not in one vast chunk - preferably by face-to-face communication and not any written documentation | https://en.wikipedia.org/wiki?curid=1902163 | 202,739 |
Technology during World War II After World War I, the concept of massed aerial bombing—"The bomber will always get through"—had become very popular with politicians and military leaders seeking an alternative to the carnage of trench warfare, and as a result, the air forces of Britain, France, and Germany had developed fleets of bomber planes to enable this (France's bomber wing was severely neglected, whilst Germany's bombers were developed in secret as they were explicitly forbidden by the Treaty of Versailles). The bombing of Shanghai by the Imperial Japanese Navy on January 28, 1932, and August 1937 and the bombings during the Spanish Civil War (1936–1939), had demonstrated the power of strategic bombing, and so air forces in Europe and the United States came to view bomber aircraft as extremely powerful weapons which, in theory, could bomb an enemy nation into submission on their own. As a result, the fear of bombers triggered major developments in aircraft technology. The Spanish Civil War had proved that tactical dive-bombing using Stukas was a very efficient way of destroying enemy troops concentrations, and so resources and money had been devoted to the development of smaller bomber craft. As a result, the Luftwaffe was forced to attack London in 1940 with heavily overloaded Heinkel and Dornier medium bombers, and even with the unsuitable Junkers Ju 87 | https://en.wikipedia.org/wiki?curid=326225 | 236,770 |
Immune Therapy Holdings AB or ITH is a Swedish biotechnology R&D holding company headquartered at the Karolinska Institutet and Karolinska University Hospital in Stockholm. ITH's research is primarily focused on its Tailored Leukapheresis (TLA) treatment for immune mediated inflammatory diseases (IMIDs). Tailored Leukapheresis (TLA) treatment is an apheresis immunotherapy for selective removal of disease-causing pro-inflammatory cells extracorporeally, which has therapeutic application in various IMIDs that are caused and maintained by inflammation. TLA utilises the natural affinity of chemokines and chemokine receptors to selectively attract, bind, and deplete circulating pro-inflammatory cells "en route" to the site of inflammation. It is the first, and hitherto novel, apheresis technology with a demonstrated efficacy in targeting and removing selected leukocytes while leaving all other blood cells unaffected. The immunotherapy has been evaluated in a Phase I/II placebo-controlled clinical trial, where all primary and secondary clinical endpoints were met and the treatment showed an absence of any side effects of clinical significance. TLA received the Dagens Medicin's Athena Prize (Sweden, 2013) and Universal Biotech Innovation Prize (France, 2012). During 2014, TLA was selected by the Swedish Institute for its Innovative Sweden exhibition that highlights Swedish innovativeness worldwide. TLA has received competitive research funding from the following sources: The global anti-inflammatory therapeutics market was $57 | https://en.wikipedia.org/wiki?curid=42277447 | 164,219 |
Broadcast television systems Use of inexpensive deinterlacing hardware is a typical difference between lower- vs. higher-priced flat panel displays (Plasma display, LCD, etc.). All films and other filmed material shot at 24 frames per second must be transferred to video frame rates using a telecine in order to prevent severe motion jitter effects. Typically, for 25 frame/s formats (European among other countries with 50 Hz mains supply), the content is PAL speedup, while a technique known as "" is used for 30 frame/s formats (North America among other countries with 60 Hz mains supply) to match the film frame rate to the video frame rate without speeding up the play back. Analog television signal standards are designed to be displayed on a cathode ray tube (CRT), and so the physics of these devices necessarily controls the format of the video signal. The image on a CRT is painted by a moving beam of electrons which hits a phosphor coating on the front of the tube. This electron beam is steered by a magnetic field generated by powerful electromagnets close to the source of the electron beam. In order to reorient this magnetic steering mechanism, a certain amount of time is required due to the inductance of the magnets; the greater the change, the greater the time it takes for the electron beam to settle in the new spot | https://en.wikipedia.org/wiki?curid=441611 | 417,949 |
Collision-induced absorption and emission Molecules have centers of positive charge (the nuclei), which are surrounded by a cloud of electrons. Molecules thus may be thought of being surrounded by various electric multipolar fields which will polarize any collisional partner momentarily in a fly-by encounter, generating the so-called multipole-induced dipoles. In diatomic molecules such as H and N, the lowest-order multipole moment is the quadrupole, followed by a hexadecapole, etc., hence the quadrupole-induced, hexadecapole-induced... dipoles. Especially the former is often the strongest, most significant of the induced dipoles contributing to CIA and CIE. Other induced dipole mechanisms exist. In collisional systems involving molecules of three or more atoms (CO, CH...), collisional frame distortion may be an important induction mechanism. Collision-induced emission and absorption by simultaneous collisions of three or more particles generally do involve pairwise-additive dipole components, as well as important irreducible dipole contributions and their spectra. Collision-induced absorption was first reported in compressed oxygen gas in 1949 by Harry Welsch and associates at frequencies of the fundamental band of the O molecule. (Note that an unperturbed O molecule, like all other diatomic homonuclear molecules, is infrared inactive on account of the inversion symmetry and does thus not possess a "dipole allowed" rotovibrational spectrum at any frequency). Molecular fly-by collisions take little time, something like 10 s | https://en.wikipedia.org/wiki?curid=39720117 | 18,188 |
Foxfire After many more literary references to foxfire by early scientists and naturalists, its cause was discovered in 1823. The glow emitted from wooden support beams in mines was examined, and it was found that the luminescence came from fungal growth. The "fox" in "foxfire" may derive from the Old French word "fols", meaning "false", rather than from the name of the animal. The association of foxes with such fires is widespread, however, and occurs also in Japanese folklore. | https://en.wikipedia.org/wiki?curid=1248534 | 50,019 |
Copper interconnects Resistance to electromigration, the process by which a metal conductor changes shape under the influence of an electric current flowing through it and which eventually leads to the breaking of the conductor, is significantly better with copper than with aluminium. This improvement in electromigration resistance allows higher currents to flow through a given size copper conductor compared to aluminium. The combination of a modest increase in conductivity along with this improvement in electromigration resistance was to prove highly attractive. The overall benefits derived from these performance improvements were ultimately enough to drive full-scale investment in copper-based technologies and fabrication methods for high performance semiconductor devices, and copper-based processes continue to be the state of the art for the semiconductor industry today. | https://en.wikipedia.org/wiki?curid=230641 | 25,152 |
Hire purchase A hire purchase (HP), known as installment plan is an arrangement whereby a customer agrees to a contract to acquire an asset by paying an initial installment (e.g. 40% of the total) and repays the balance of the price of the asset plus interest over a period of time. Other analogous practices are described as closed-end leasing or rent to own. The hire purchase agreement was developed in the United Kingdom in the 19th century to allow customers with a cash shortage to make an expensive purchase they otherwise would have to delay or forgo. For example, in cases where a buyer cannot afford to pay the asked price for an item of property as a lump sum but can afford to pay a percentage as a deposit, a hire-purchase contract allows the buyer to hire the goods for a monthly rent. When a sum equal to the original full price plus interest has been paid in equal installments, the buyer may then exercise an option to buy the goods at a predetermined price (usually a nominal sum) or return the goods to the owner. If the buyer defaults in paying the installments, the owner may repossess the goods. A vendor protection not available with unsecured-consumer-credit systems. HP is frequently advantageous to consumers because it spreads the cost of expensive items over an extended time period. Business consumers may find the different balance sheet and taxation treatment of hire-purchased goods beneficial to their taxable income | https://en.wikipedia.org/wiki?curid=690485 | 484,996 |
Homometric structures In chemistry and crystallography, crystal structures that have the same set of interatomic distances are called homometric structures. need not be congruent (that is, related by a rigid motion or reflection). Homometric crystal structures produce identical diffraction patterns; therefore, they cannot be distinguished by a diffraction experiment. Recently, a Monte Carlo algorithm was proposed to calculate the number of homometric structures corresponding to any given set of interatomic distances. | https://en.wikipedia.org/wiki?curid=10766478 | 11,584 |
Test probe Probing with a matching 50-ohm transmission line would offer high frequency performance, but it would unduly load most circuits. An attenuator (resistive divider) can be used to minimize loading. At the tip, these probes use a 450 ohm (for 10× attenuation) or 950 ohm (for 20× attenuation) series resistor. Tektronix sells a 10× divider probe with a 9 GHz bandwidth with a 450 ohm series resistor. These probes are also called resistive divider probes, since a 50 ohm transmission line presents a purely resistive load. The "Z" name refers to the characteristic impedance of the oscilloscope and cable. The matched impedances provide better high-frequency performance than an unmatched passive probe can achieve, but at the expense of the low 500-ohm load offered by the probe tip to the DUT. Parasitic capacitance at the probe tip is very low so, for very high-frequency signals, the Z probe can offer lower loading than any hi-Z probe and even many active probes. In principle this type of probe can be used at any frequency, but at DC and lower frequencies circuits often have high impedances that would be unacceptably loaded by the probe's low 500 or 1000 ohm probe impedance. Parasitic impedances limit very-high-frequency circuits to operating at low impedance, so the probe impedance is less of a problem. Active scope probes use a high-impedance high-frequency amplifier mounted in the probe head, and a screened lead | https://en.wikipedia.org/wiki?curid=5260820 | 271,729 |
Radical polymerization If free rotation does not occur before the next monomer adds, the mirror approach will always lead to an isotactic polymer and the non-mirror approach will always lead to a syndiotactic polymer (Figure 25). However, if interactions between the substituents of the penultimate repeating unit and the terminal carbon atom are significant, then conformational factors could cause the monomer to add to the polymer in a way that minimizes steric or electrostatic interaction (Figure 26). Traditionally, the reactivity of monomers and radicals are assessed by the means of copolymerization data. The "Q–e" scheme, the most widely used tool for the semi-quantitative prediction of monomer reactivity ratios, was first proposed by Alfrey and Price in 1947. The scheme takes into account the intrinsic thermodynamic stability and polar effects in the transition state. A given radical formula_16 and a monomer formula_17 are considered to have intrinsic reactivities P and Q, respectively. The polar effects in the transition state, the supposed permanent electric charge carried by that entity (radical or molecule), is quantified by the factor "e", which is a constant for a given monomer, and has the same value for the radical derived from that specific monomer | https://en.wikipedia.org/wiki?curid=1947467 | 70,804 |
Cascade chart (NDI interval reliability) A cascade chart is tool that can be used in damage tolerance analysis to determine the proper inspection interval, based on reliability analysis, considering all the context uncertainties. The chart is called a "cascade chart" because the scatter of data points and downward curvature resembles a waterfall or cascade. This name was first introduced by Dr. Alberto W Mello in his work "Reliability prediction for structures under cyclic loads and recurring inspections". Materials subject to cyclic loads, as shown in the graph on the right, may form and propagate cracks over time due to fatigue. Therefore, it is essential to determine a reliable inspection interval. There are numerous factors that must be considered to determine this inspection interval. The non-destructive inspection (NDI) technique must have a high probability of detecting a crack in the material. If missed, a crack may lead the structure to a catastrophic failure before the next inspection. On the other hand, the inspection interval cannot be too frequent that the structure's maintenance is no longer profitable. NDI is a process used to examine materials without causing damage to the structure. The main purpose of using NDI techniques is to comb the surface of a material for small cracks that could affect the integrity of the entire structure. Because the structure is intended to be used again, it is essential that the methods of investigating materials for cracks does not damage the structure in any way | https://en.wikipedia.org/wiki?curid=53798296 | 336,960 |
Crossover experiment (chemistry) The amount of time it takes a given molecule to “escape” this solvent cage varies with the size of the molecule and the strength of the intermolecular forces of the solvent, but is considered to be on the order of 1 x 10 seconds. If a reaction occurs faster than the molecules are able to escape the solvent cage, then only non-crossover products will be observed, masking the true reaction mechanism. When the timescale of the reaction is much slower than the timescale of the solvent cage effect, dissociated species are able to escape the solvent cage and form crossover products. This is an appropriate representation of a reaction in a crossover experiment occurring via an intermolecular mechanism and forming crossover products as expected. When the timescale of the reaction is faster than or on the same order as the timescale of the solvent cage effect this is a more accurate representation of the same crossover experiment as above. Although a dissociative or intermolecular mechanism is occurring, no crossover occurs because the timescale of the reaction is sufficiently short that the dissociated fragment remains trapped within the solvent cage. The effect of the solvent cage on crossover experiments is not a purely theoretical concept. One of the first pieces of experimental evidence for the existence of the solvent cage was the observation of the solvent cage effect on a crossover experiment | https://en.wikipedia.org/wiki?curid=40913419 | 6,374 |
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