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of a single linear progression. == Punctuated equilibrium == The theory of punctuated equilibrium developed by Stephen Jay Gould and Niles Eldredge and first presented in 1972 is often mistakenly drawn into the discussion of transitional fossils. This theory, however, pertains only to well-documented transitions within...	{ "page_id": 331755, "title": "Transitional fossil" }
A spectrochemical series is a list of ligands ordered by ligand "strength", and a list of metal ions based on oxidation number, group and element. For a metal ion, the ligands modify the difference in energy Δ between the d orbitals, called the ligand-field splitting parameter in ligand field theory, or the crystal-fie...	{ "page_id": 3936237, "title": "Spectrochemical series" }
highlights the weakness of its assumption of purely ionic bonds between metal and ligand. The order of the spectrochemical series can be derived from the understanding that ligands are frequently classified by their donor or acceptor abilities. Some, like NH3, are σ bond donors only, with no orbitals of appropriate sym...	{ "page_id": 3936237, "title": "Spectrochemical series" }
of transition metals == References == Zumdahl, Steven S. Chemical Principles Fifth Edition. Boston: Houghton Mifflin Company, 2005. Pages 550-551 and 957-964. D. F. Shriver and P. W. Atkins Inorganic Chemistry 3rd edition, Oxford University Press, 2001. Pages: 227-236. James E. Huheey, Ellen A. Keiter, and Richard L. K...	{ "page_id": 3936237, "title": "Spectrochemical series" }
Epi-lipoxins are trihydroxy (i.e. containing 3 hydroxyl residues) metabolites of arachidonic acid. They are 15R-epimers of their lipoxin counterparts; that is, the epi-lipoxins, 15-epi-lipoxin A4 (15-epi-LxA4) and 15-epi-lipoxin B4 (15-epi-LXB4), differ from their respective lipoxin A4 (LxA4) and lipoxin B4 (LxB4) epim...	{ "page_id": 14028784, "title": "Epi-lipoxin" }
Count Apollos Apollosovich Musin-Pushkin (Russian: Аполло́с Аполло́сович Му́син-Пу́шкин; February 17, 1760 – April 18, 1805) was a Russian chemist and plant collector. He led a botanical expedition to the Caucasus in 1802 with his friend botanist Friedrich August Marschall von Bieberstein. In 1797, he was elected a for...	{ "page_id": 1183728, "title": "Apollo Mussin-Pushkin" }
Aavo Sirk (born in 1945) is an Estonian physicist. He has worked at National Institute of Chemical Physics and Biophysics He gave his signature to Letter of 40 intellectuals. In 2006, he was awarded with Order of the National Coat of Arms, IV class. == References ==	{ "page_id": 67178482, "title": "Aavo Sirk" }
A kleptoprotein is a protein which is not encoded in the genome of the organism which uses it, but instead is obtained through diet from a prey organism. Importantly, a kleptoprotein must maintain its function and be mostly or entirely undigested, drawing a distinction from proteins that are digested for nutrition, whi...	{ "page_id": 62787574, "title": "Kleptoprotein" }
Debasisa Mohanty (born 30 November 1966) is an Indian computational biologist, bioinformatician and a staff scientists at the National Institute of Immunology, India. Known for his studies on structure and function prediction of proteins, genome analysis and computer simulation of biomolecular systems, Mohanty is an el...	{ "page_id": 56365055, "title": "Debasisa Mohanty" }
putative proteins in genomes and the protein interaction networks in newly sequenced genomes. His studies have been documented by way of a number of articles and ResearchGate, an online repository of scientific articles has listed 108 of them. Mohanty was a member of the national organizing committee of the Internation...	{ "page_id": 56365055, "title": "Debasisa Mohanty" }
27928938. S2CID 11253090. Khater, Shradha; Anand, Swadha; Mohanty, Debasisa (2016). "In silico methods for linking genes and secondary metabolites: The way forward". Synthetic and Systems Biotechnology. 1 (2): 80–88. doi:10.1016/j.synbio.2016.03.001. PMC 5640692. PMID 29062931. == See also == == Notes == == References ...	{ "page_id": 56365055, "title": "Debasisa Mohanty" }
Several chromosome regions have been defined by convenience and convention in order to talk about gene loci. The largest regions on each chromosome are the short arm p and the long arm q, separated by a narrow region near the center called the centromere. Other specific regions have also been defined, some of which are...	{ "page_id": 2101248, "title": "Chromosome regions" }
centromere nor the telomeres, but are roughly in the middle of p or q. == See also == Satellite chromosome == References ==	{ "page_id": 2101248, "title": "Chromosome regions" }
The molecular formula C11H13NS (molar mass: 191.29 g/mol, exact mass: 191.076871 u) may refer to: 2-APBT 3-APBT 4-APBT 5-APBT 6-APBT 7-APBT	{ "page_id": 79171585, "title": "C11H13NS" }
The molecular formula C16H18N2O7S2 (molar mass: 414.453 g/mol) may refer to: Sulbenicillin Temocillin	{ "page_id": 24711175, "title": "C16H18N2O7S2" }
Cell migration is a central process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular directions to specific locations. Cells often migrate in response to specific ...	{ "page_id": 2428938, "title": "Cell migration" }
consistent with those of (non-spermatozooic) locomotion. Observations in common include: cytoplasmic displacement at leading edge (front) laminar removal of dorsally-accumulated debris toward trailing edge (back) The latter feature is most easily observed when aggregates of a surface molecule are cross-linked with a fl...	{ "page_id": 2428938, "title": "Cell migration" }
extend the front edge (polarized in the direction of movement), but have difficulty retracting their trailing edge. On the other hand, high drug concentrations, or microtubule mutations that depolymerize the microtubules, can restore cell migration but there is a loss of directionality. It can be concluded that microtu...	{ "page_id": 2428938, "title": "Cell migration" }
measured. === Mechanistic basis of amoeboid migration === Adhesive crawling is not the only migration mode exhibited by eukaryotic cells. Importantly, several cell types — Dictyostelium amoebae, neutrophils, metastatic cancer cells and macrophages — have been found to be capable of adhesion-independent migration. Histo...	{ "page_id": 2428938, "title": "Cell migration" }
filaments, their propagation and zigzagging motion on the membrane generate a highly interlinked network of curved or linear filaments oriented at a wide spectrum of angles to the cell boundary. It is also proposed that microdomain interaction marks the formation of new focal adhesion sites at the cell periphery. Myosi...	{ "page_id": 2428938, "title": "Cell migration" }
play in many cell processes. It may be that, as part of the locomotory process, membrane vesicles are transported along these filaments to the cell's front. In chemotaxing cells, the increased persistence of migration toward the target may result from an increased stability of the arrangement of the filamentous structu...	{ "page_id": 2428938, "title": "Cell migration" }
conditions == Cell migration could be affected in some pathological states. For example, in conditions of high lipoperoxidation, actin has been shown to be post-translationally modified by the lipoperoxidation product 4-hydroxynonenal (4-HNE). This modification prevents the remodelling of the actin cytoskeleton, which ...	{ "page_id": 2428938, "title": "Cell migration" }
Leopold Blaschka (27 May 1822 – 3 July 1895) and his son Rudolf Blaschka (17 June 1857 – 1 May 1939) were glass artists from Dresden, Germany. They were known for their production of biological and botanical models, including glass sea creatures and Harvard University's Glass Flowers. == Family background == The Blasch...	{ "page_id": 25235466, "title": "Leopold and Rudolf Blaschka" }
and glass eyes. Leopold developed a technique which he termed "glass-spinning" which permitted the construction of highly precise and detailed works in glass. He soon began to focus the business on manufacturing glass eyes. In 1846, Leopold married Caroline Zimmermann, and within four years their son Josef Augustin Bla...	{ "page_id": 25235466, "title": "Leopold and Rudolf Blaschka" }
later. During this period, Blaschka did not make any money producing the models. Eventually, however, the models attracted the attention of Prince Camille de Rohan, who arranged to meet with Leopold at Sychrov Castle in 1857. Prince Camille, an enthusiast of natural sciences, commissioned Leopold to craft 100 glass orc...	{ "page_id": 25235466, "title": "Leopold and Rudolf Blaschka" }
Society of Natural History Museum (now the Museum of Science). These models, along with the ones purchased by Harvard's Museum of Comparative Zoology, were seen by Professor George Lincoln Goodale, who was in the process of establishing and building the Harvard Botanical Museum's collection. In 1886, Goodale, traveled ...	{ "page_id": 25235466, "title": "Leopold and Rudolf Blaschka" }
and do the sea creatures during the other half, declaring that they “must give up either one or the other." To resolve this, the Blaschkas signed an exclusive ten-year contract with Harvard to make glass flowers for 8,800 marks per year. New arrangements were also made to send the models directly to Harvard, where muse...	{ "page_id": 25235466, "title": "Leopold and Rudolf Blaschka" }
his earliest studies. == Production of Glass Flowers == Claims arose that Leopold and his son were using secret methods to make their glass models. These claims were refuted by Leopold himself. Blaschka stated "One cannot hurry glass. It will take its own time. If we try to hasten it beyond its limits, it resists and n...	{ "page_id": 25235466, "title": "Leopold and Rudolf Blaschka" }
and all the enamels, which he uses powders to use as paint." In addition to funding and visiting the project, Mary took an active role in its progress, going so far as to personally unpack each model and make arrangements for Rudolph's fieldwork in the U.S. and Jamaica. Ames was less passionate about the Glass Flowers ...	{ "page_id": 25235466, "title": "Leopold and Rudolf Blaschka" }
Dresden in World War II and, in 1993, the Corning Museum of Glass and Harvard Museum of Natural History jointly purchased the remaining Blaschka studio materials from Frieda Blaschka's niece, Gertrud Pones. The Pisa Charterhouse, which houses the Museum of Natural History of the University of Pisa, has a collection of ...	{ "page_id": 25235466, "title": "Leopold and Rudolf Blaschka" }
In statistical mechanics and mathematics, a Boltzmann distribution (also called Gibbs distribution) is a probability distribution or probability measure that gives the probability that a system will be in a certain state as a function of that state's energy and the temperature of the system. The distribution is express...	{ "page_id": 4107, "title": "Boltzmann distribution" }
later investigated extensively, in its modern generic form, by Josiah Willard Gibbs in 1902. The Boltzmann distribution should not be confused with the Maxwell–Boltzmann distribution or Maxwell-Boltzmann statistics. The Boltzmann distribution gives the probability that a system will be in a certain state as a function ...	{ "page_id": 4107, "title": "Boltzmann distribution" }
⋯ , p M ) = − ∑ i = 1 M p i log 2 ⁡ p i {\displaystyle S(p_{1},p_{2},\cdots ,p_{M})=-\sum _{i=1}^{M}p_{i}\log _{2}p_{i}} subject to the normalization constraint that ∑ p i = 1 {\textstyle \sum p_{i}=1} and the constraint that ∑ p i ε i {\textstyle \sum {p_{i}{\varepsilon }_{i}}} equals a particular mean energy value, e...	{ "page_id": 4107, "title": "Boltzmann distribution" }
that, if we pick a random particle from that system and check what state it is in, we will find it is in state i. This probability is equal to the number of particles in state i divided by the total number of particles in the system, that is the fraction of particles that occupy state i. p i = N i N {\displaystyle p_{i...	{ "page_id": 4107, "title": "Boltzmann distribution" }
as whether it is caused by an allowed or a forbidden transition. The softmax function commonly used in machine learning is related to the Boltzmann distribution: ( p 1 , … , p M ) = softmax ⁡ [ − ε 1 k T , … , − ε M k T ] {\displaystyle (p_{1},\ldots ,p_{M})=\operatorname {softmax} \left[-{\frac {\varepsilon _{1}}{kT}}...	{ "page_id": 4107, "title": "Boltzmann distribution" }
possible states of a closed system of fixed volume, in thermal equilibrium with a heat bath. The canonical ensemble has a state probability distribution with the Boltzmann form. Statistical frequencies of subsystems' states (in a non-interacting collection) When the system of interest is a collection of many non-intera...	{ "page_id": 4107, "title": "Boltzmann distribution" }
ensemble can however still be applied to the collective states of the entire system considered as a whole, provided the entire system is in thermal equilibrium. With quantum gases of non-interacting particles in equilibrium, the number of particles found in a given single-particle state does not follow Maxwell–Boltzman...	{ "page_id": 4107, "title": "Boltzmann distribution" }
Bioleaching is the extraction or liberation of metals from their ores through the use of living organisms. Bioleaching is one of several applications within biohydrometallurgy and several methods are used to treat ores or concentrates containing copper, zinc, lead, arsenic, antimony, nickel, molybdenum, gold, silver, a...	{ "page_id": 4111, "title": "Bioleaching" }
+ {\displaystyle \mathrm {FeS_{2}+6\ Fe^{\,3+}+3\ H_{2}O\longrightarrow 7\ Fe^{\,2+}+S_{2}O_{3}^{\,2-}+6\ H^{+}} } spontaneous The ferrous ion is then oxidized by bacteria using oxygen: (2) 4 F e 2 + + O 2 + 4 H + ⟶ 4 F e 3 + + 2 H 2 O {\displaystyle \mathrm {4\ Fe^{\,2+}+\ O_{2}+4\ H^{+}\longrightarrow 4\ Fe^{\,3+}+2\...	{ "page_id": 4111, "title": "Bioleaching" }
the two stages of being dissolved and then further oxidised, with Cu2+ ions being left in solution. Chalcopyrite leaching: (1) C u F e S 2 + 4 F e 3 + ⟶ C u 2 + + 5 F e 2 + + 2 S 0 {\displaystyle \mathrm {CuFeS_{2}+4\ Fe^{\,3+}\longrightarrow Cu^{\,2+}+5\ Fe^{\,2+}+2\ S_{0}} } spontaneous (2) 4 F e 2 + + O 2 + 4 H + ⟶ ...	{ "page_id": 4111, "title": "Bioleaching" }
which leaves other ions in the solution. The copper is removed by bonding to a ligand, which is a large molecule consisting of a number of smaller groups, each possessing a lone electron pair. The ligand-copper complex is extracted from the solution using an organic solvent such as kerosene: Cu2+(aq) + 2LH(organic) → C...	{ "page_id": 4111, "title": "Bioleaching" }
fly ash from municipal waste incineration. Experiments have shown that two fungal strains (Aspergillus niger, Penicillium simplicissimum) were able to mobilize Cu and Sn by 65%, and Al, Ni, Pb, and Zn by more than 95%. Aspergillus niger can produce some organic acids such as citric acid. This form of leaching does not ...	{ "page_id": 4111, "title": "Bioleaching" }
end up in debt. === In space === In 2020 scientists showed, with an experiment with different gravity environments on the ISS, that microorganisms could be employed to mine useful elements from basaltic rocks via bioleaching in space. == Environmental impact == The process is more environmentally friendly than traditio...	{ "page_id": 4111, "title": "Bioleaching" }
J. A.; Brierley, C. L. (2003). "Bioleaching review part B". Applied Microbiology and Biotechnology. 63 (3): 249–57. doi:10.1007/s00253-003-1404-6. PMID 14566430. S2CID 24078490. Rohwerder, T.; Gehrke, T.; Kinzler, K.; Sand, W. (2003). "Bioleaching review part A". Applied Microbiology and Biotechnology. 63 (3): 239–248....	{ "page_id": 4111, "title": "Bioleaching" }
KREEP, an acronym built from the letters K (the atomic symbol for potassium), REE (rare-earth elements) and P (for phosphorus), is a geochemical component of some lunar impact breccia and basaltic rocks. Its most significant feature is somewhat enhanced concentration of a majority of so-called "incompatible" elements (...	{ "page_id": 200719, "title": "KREEP" }
are usually incompatible (i.e., those that usually partition in the liquid phase) would have been progressively concentrated into the magma. Thus a KREEP-rich magma was formed that was sandwiched at first between the crust and mantle. The evidence for these processes comes from the highly anorthositic composition of th...	{ "page_id": 200719, "title": "KREEP" }
Moon articles in Planetary Science Research Discoveries, including articles about KREEP	{ "page_id": 200719, "title": "KREEP" }
A viability assay is an assay that is created to determine the ability of organs, cells or tissues to maintain or recover a state of survival. Viability can be distinguished from the all-or-nothing states of life and death by the use of a quantifiable index that ranges between the integers of 0 and 1 or, if more easily...	{ "page_id": 28643345, "title": "Viability assay" }
target viability in cells; this practice in research is known as "Protease Viability Marker Assay Concept". The actions of protease cease once a cell dies, so a clear-cut line is drawn in determining cell viability when using this technique. ATP:ATP is a common energy molecule that many researchers hold extensive knowl...	{ "page_id": 28643345, "title": "Viability assay" }
and proteomic: Cells can be assayed for activation of stress pathways using DNA microarrays and protein chips. Flow Cytometry: Automation allows for analysis of thousands of cells per second. As with many kinds of viability assays, quantitative measures of physiological function do not indicate whether damage repair an...	{ "page_id": 28643345, "title": "Viability assay" }
Hydroperoxides or peroxols are compounds of the form ROOH, where R stands for any group, typically organic, which contain the hydroperoxy functional group (−OOH). Hydroperoxide also refers to the hydroperoxide anion (−OOH) and its salts, and the neutral hydroperoxyl radical (•OOH) consist of an unbond hydroperoxy group...	{ "page_id": 3411988, "title": "Hydroperoxide" }
the metal-catalysed epoxidation of alkenes." In the Halcon process tert-butyl hydroperoxide (TBHP) is employed for the production of propylene oxide. Of specialized interest, chiral epoxides are prepared using hydroperoxides as reagents in the Sharpless epoxidation. === Production of cyclohexanone and caprolactone === ...	{ "page_id": 3411988, "title": "Hydroperoxide" }
residue. Although ether hydroperoxide often form adventitiously (i.e. autoxidation), they can be prepared in high yield by the acid-catalyzed addition of hydrogen peroxide to vinyl ethers: C2H5OCH=CH2 + H2O2 → C2H5OCH(OOH)CH3 === From hydrogen peroxide === Many industrial peroxides are produced using hydrogen peroxide....	{ "page_id": 3411988, "title": "Hydroperoxide" }
==	{ "page_id": 3411988, "title": "Hydroperoxide" }
The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models based on the Big Bang concept explain a broad range of phenomena, including the abundance of light elements, the cosmic microwave background (CMB) radiation, and ...	{ "page_id": 4116, "title": "Big Bang" }
observations, physicist Georges Lemaître proposed that the universe emerged from a "primeval atom" in 1931, introducing the modern notion of the Big Bang. In 1964, the CMB was discovered. Over the next few years measurements showed this radiation to be uniform over directions in the sky and the shape of the energy vers...	{ "page_id": 4116, "title": "Big Bang" }
cosmological principle has been confirmed to a level of 10−5 via observations of the temperature of the CMB. At the scale of the CMB horizon, the universe has been measured to be homogeneous with an upper bound on the order of 10% inhomogeneity, as of 1995. === Expansion prediction === The cosmological principle dramat...	{ "page_id": 4116, "title": "Big Bang" }
objects. This defines a future horizon, which limits the events in the future that we will be able to influence. The presence of either type of horizon depends on the details of the Friedmann–Lemaître–Robertson–Walker (FLRW) metric that describes the expansion of the universe. Our understanding of the universe back to ...	{ "page_id": 4116, "title": "Big Bang" }
physics under these conditions.: 275 Quantum gravity effects are expected to be dominant during the Planck epoch, when the temperature of the universe was close to the Planck scale (around 1032 K or 1028 eV). Even below the Planck scale, undiscovered physics could greatly influence the expansion history of the universe...	{ "page_id": 4116, "title": "Big Bang" }
by the light speed invariance, and temperatures dropped by a factor of 100,000. This concept is motivated by the flatness problem, where the density of matter and energy is very close to the critical density needed to produce a flat universe. That is, the shape of the universe has no overall geometric curvature due to ...	{ "page_id": 4116, "title": "Big Bang" }
seconds. After about 10−11 seconds, the picture becomes less speculative, since particle energies drop to values that can be attained in particle accelerators. At about 10−6 seconds, quarks and gluons combined to form baryons such as protons and neutrons. The small excess of quarks over antiquarks led to a small excess...	{ "page_id": 4116, "title": "Big Bang" }
the other astronomical structures observable today. The details of this process depend on the amount and type of matter in the universe. The four possible types of matter are known as cold dark matter (CDM), warm dark matter, hot dark matter, and baryonic matter. The best measurements available, from the Wilkinson Micr...	{ "page_id": 4116, "title": "Big Bang" }
describe the situation prior to approximately 10−15 seconds. Understanding this earliest of eras in the history of the universe is one of the greatest unsolved problems in physics. == Concept history == === Etymology === English astronomer Fred Hoyle is credited with coining the term "Big Bang" during a talk for a Marc...	{ "page_id": 4116, "title": "Big Bang" }
— the television science reporter Hugh Downs, the astronomer Carl Sagan, and myself — sifted through 13,099 entries from 41 countries and concluded that none was apt enough to replace it. No winner was declared, and like it or not, we are stuck with 'big bang'. === Before the name === Early cosmological models develope...	{ "page_id": 4116, "title": "Big Bang" }
principle. In 1931, Lemaître went further and suggested that the evident expansion of the universe, if projected back in time, meant that the further in the past the smaller the universe was, until at some finite time in the past all the mass of the universe was concentrated into a single point, a "primeval atom" where...	{ "page_id": 4116, "title": "Big Bang" }
is roughly the same at any point in time. The other was Lemaître's expanding universe theory, advocated and developed by George Gamow, who used it to develop a theory for the abundance of chemical elements in the universe. and whose associates, Ralph Alpher and Robert Herman, predicted the cosmic background radiation. ...	{ "page_id": 4116, "title": "Big Bang" }
advances in telescope technology as well as the analysis of data from satellites such as the Cosmic Background Explorer (COBE), the Hubble Space Telescope and WMAP. Cosmologists now have fairly precise and accurate measurements of many of the parameters of the Big Bang model, and have made the unexpected discovery that...	{ "page_id": 4116, "title": "Big Bang" }
of distant galaxies and quasars show that these objects are redshifted: the light emitted from them has been shifted to longer wavelengths. This can be seen by taking a frequency spectrum of an object and matching the spectroscopic pattern of emission or absorption lines corresponding to atoms of the chemical elements ...	{ "page_id": 4116, "title": "Big Bang" }
as the Doppler shift corresponding to the recession velocity v {\displaystyle v} . For distances comparable to the size of the observable universe, the attribution of the cosmological redshift becomes more ambiguous, although its interpretation as a kinematic Doppler shift remains the most natural one. An unexplained d...	{ "page_id": 4116, "title": "Big Bang" }
of 2.726 K (more recent measurements have revised this figure down slightly to 2.7255 K); then in 1992, further COBE measurements discovered tiny fluctuations (anisotropies) in the CMB temperature across the sky, at a level of about one part in 105. John C. Mather and George Smoot were awarded the 2006 Nobel Prize in P...	{ "page_id": 4116, "title": "Big Bang" }
for 4He, and off by a factor of two for 7Li (this anomaly is known as the cosmological lithium problem); in the latter two cases, there are substantial systematic uncertainties. Nonetheless, the general consistency with abundances predicted by BBN is strong evidence for the Big Bang, as the theory is the only known exp...	{ "page_id": 4116, "title": "Big Bang" }
to be pristine clouds of primordial gas by analyzing absorption lines in the spectra of distant quasars. Before this discovery, all other astronomical objects have been observed to contain heavy elements that are formed in stars. Despite being sensitive to carbon, oxygen, and silicon, these three elements were not dete...	{ "page_id": 4116, "title": "Big Bang" }
time, making precise measurements difficult. === Future observations === Future gravitational-wave observatories might be able to detect primordial gravitational waves, relics of the early universe, up to less than a second after the Big Bang. == Problems and related issues in physics == As with any theory, a number of...	{ "page_id": 4116, "title": "Big Bang" }
account for the asymmetry. For baryogenesis to occur, the Sakharov conditions must be satisfied. These require that baryon number is not conserved, that C-symmetry and CP-symmetry are violated and that the universe depart from thermodynamic equilibrium. All these conditions occur in the Standard Model, but the effects ...	{ "page_id": 4116, "title": "Big Bang" }
1% neutrinos. According to theory, the energy density in matter decreases with the expansion of the universe, but the dark energy density remains constant (or nearly so) as the universe expands. Therefore, matter made up a larger fraction of the total energy of the universe in the past than it does today, but its fract...	{ "page_id": 4116, "title": "Big Bang" }
particles have been observed in laboratories. Many particle physics candidates for dark matter have been proposed, and several projects to detect them directly are underway. Additionally, there are outstanding problems associated with the currently favored cold dark matter model which include the dwarf galaxy problem a...	{ "page_id": 4116, "title": "Big Bang" }
phase there would be quantum thermal fluctuations, which would be magnified to a cosmic scale. These fluctuations served as the seeds for all the current structures in the universe.: 207 Inflation predicts that the primordial fluctuations are nearly scale invariant and Gaussian, which has been confirmed by measurements...	{ "page_id": 4116, "title": "Big Bang" }
might be the Planck time, 10−43 seconds, the fact that the universe has reached neither a heat death nor a Big Crunch after billions of years requires an explanation. For instance, even at the relatively late age of a few minutes (the time of nucleosynthesis), the density of the universe must have been within one part ...	{ "page_id": 4116, "title": "Big Bang" }
of space. This can be misleading because the expansion of space is only a coordinate choice. The most natural interpretation of the cosmological redshift is that it is a Doppler shift. == Implications == Given current understanding, scientific extrapolations about the future of the universe are only possible for finite...	{ "page_id": 4116, "title": "Big Bang" }
of quantum gravity. Certain quantum gravity treatments, such as the Wheeler–DeWitt equation, imply that time itself could be an emergent property. As such, physics may conclude that time did not exist before the Big Bang. While it is not known what could have preceded the hot dense state of the early universe or how an...	{ "page_id": 4116, "title": "Big Bang" }
universe, expanding from its own big bang. This is sometimes referred to as pre-big bang inflation. Proposals in the last two categories see the Big Bang as an event in either a much larger and older universe or in a multiverse. === Ultimate fate of the universe === Before observations of dark energy, cosmologists cons...	{ "page_id": 4116, "title": "Big Bang" }
together, and they too will be subject to heat death as the universe expands and cools. Other explanations of dark energy, called phantom energy theories, suggest that ultimately galaxy clusters, stars, planets, atoms, nuclei, and matter itself will be torn apart by the ever-increasing expansion in a so-called Big Rip....	{ "page_id": 4116, "title": "Big Bang" }
H.; Davis, Tamara M. (March 2005). "Misconceptions about the Big Bang" (PDF). Scientific American. Vol. 292, no. 3. pp. 36–45. Archived (PDF) from the original on 9 October 2019. Retrieved 23 December 2019. Martínez-Delgado, David, ed. (2013). Local Group Cosmology. Cambridge, UK: Cambridge University Press. ISBN 978-1...	{ "page_id": 4116, "title": "Big Bang" }
illustrates a longstanding confusion over the famous term. by Sabine Hossenfelde	{ "page_id": 4116, "title": "Big Bang" }
In machine learning and statistics, the learning rate is a tuning parameter in an optimization algorithm that determines the step size at each iteration while moving toward a minimum of a loss function. Since it influences to what extent newly acquired information overrides old information, it metaphorically represents...	{ "page_id": 59969558, "title": "Learning rate" }
most common are time-based, step-based and exponential. Decay serves to settle the learning in a nice place and avoid oscillations, a situation that may arise when a too high constant learning rate makes the learning jump back and forth over a minimum, and is controlled by a hyperparameter. Momentum is analogous to a b...	{ "page_id": 59969558, "title": "Learning rate" }
0 {\displaystyle \eta _{0}} is the initial learning rate, d {\displaystyle d} is how much the learning rate should change at each drop (0.5 corresponds to a halving) and r {\displaystyle r} corresponds to the drop rate, or how often the rate should be dropped (10 corresponds to a drop every 10 iterations). The floor fu...	{ "page_id": 59969558, "title": "Learning rate" }
A belly cast is a three-dimensional plaster sculpture of a woman's pregnant abdomen as a keepsake of her pregnancy. It can also be known as a belly mask, pregnancy belly cast, a pregnant plaster cast, or prenatal cast. Belly casts are most often made toward the end of the third trimester of pregnancy, though a series o...	{ "page_id": 13111318, "title": "Belly cast" }
Hydrodesulfurization (HDS), also called hydrotreatment or hydrotreating, is a catalytic chemical process widely used to remove sulfur (S) from natural gas and from refined petroleum products, such as gasoline or petrol, jet fuel, kerosene, diesel fuel, and fuel oils. The purpose of removing the sulfur, and creating pro...	{ "page_id": 3543062, "title": "Hydrodesulfurization" }
was discovered by the French chemist Paul Sabatier in 1897. Through this work, he found that unsaturated hydrocarbons in the vapor phase could be converted into saturated hydrocarbons by using hydrogen and a catalytic metal, laying the foundation of the modern catalytic hydrogenation process. Soon after Sabatier's work...	{ "page_id": 3543062, "title": "Hydrodesulfurization" }
the hydrodesulfurization reaction can be simply expressed as C 2 H 5 SH Ethanethiol + H 2 Hydrogen ⟶ C 2 H 6 Ethane + H 2 S Hydrogen sulfide {\displaystyle {\ce {{\overset {Ethanethiol}{C2H5SH}}+{\overset {Hydrogen}{H2}}->{\overset {Ethane}{C2H6}}+{\overset {Hydrogen\ sulfide}{H2S}}}}} For the mechanistic aspects of, a...	{ "page_id": 3543062, "title": "Hydrodesulfurization" }
to 5 atmospheres. The resulting mixture of liquid and gas enters the gas separator pressure vessel at about 35 °C and 3 to 5 atmospheres of absolute pressure. Most of the hydrogen-rich gas from the gas separator vessel is recycle gas, which is routed through an amine contactor for removal of the reaction product H2S th...	{ "page_id": 3543062, "title": "Hydrodesulfurization" }
from the recycle gas contactor comes from and is returned to the refinery's main amine gas treating unit. == Sulfur compounds in refinery HDS feedstocks == The refinery HDS feedstocks (naphtha, kerosene, diesel oil, and heavier oils) contain a wide range of organic sulfur compounds, including thiols, thiophenes, organi...	{ "page_id": 3543062, "title": "Hydrodesulfurization" }
smaller amounts of other metals. The nature of the sites of catalytic activity remains an active area of investigation, but it is generally assumed basal planes of the MoS2 structure are not relevant to catalysis, rather the edges or rims of these sheet. At the edges of the MoS2 crystallites, the molybdenum centre can ...	{ "page_id": 3543062, "title": "Hydrodesulfurization" }
to as hydrodenitrogenation (HDN). The process flow is the same as that for an HDS unit. Using pyridine (C5H5N), a nitrogen compound present in some petroleum fractionation products, as an example, the hydrodenitrogenation reaction has been postulated as occurring in three steps: C 5 H 5 N Pyridine + 5 H 2 Hydrogen ⟶ C ...	{ "page_id": 3543062, "title": "Hydrodesulfurization" }
(Catalyzing Your Business) Albemarle Catalyst Company (Petrochemical catalysts supplier) UOP-Honeywell (Engineering design and construction of large-scale, industrial HDS plants) Hydrogenation for Low Trans and High Conjugated Fatty Acids by E.S. Jang, M.Y. Jung, D.B. Min, Comprehensive Reviews in Food Science and Food...	{ "page_id": 3543062, "title": "Hydrodesulfurization" }
Cutan is one of two waxy biopolymers which occur in the cuticle of some plants. The other and better-known polymer is cutin. Cutan is believed to be a hydrocarbon polymer, whereas cutin is a polyester, but the structure and synthesis of cutan are not yet fully understood. Cutan is not present in as many plants as once ...	{ "page_id": 6033433, "title": "Cutan (polymer)" }
The Oldstone Conference of 11 to 14 April 1949 was the third of three postwar conferences held to discuss quantum physics; arranged for the National Academy of Sciences by J. Robert Oppenheimer, who was again chairman. It followed the Shelter Island Conference of 1947 and the Pocono Conference of 1948. There were 24 pa...	{ "page_id": 32313371, "title": "Oldstone Conference" }
In zoology, deep-sea gigantism or abyssal gigantism is the tendency for species of deep-sea dwelling animals to be larger than their shallower-water relatives across a large taxonomic range. Proposed explanations for this type of gigantism include necessary adaptation to colder temperature, food scarcity, reduced preda...	{ "page_id": 20975650, "title": "Deep-sea gigantism" }
actually exhibit the reverse trend of decreasing size with depth. == Explanations == === Lower temperature === In crustaceans, it has been proposed that the explanation for the increase in size with depth is similar to that for the increase in size with latitude (Bergmann's rule): both trends involve increasing size wi...	{ "page_id": 20975650, "title": "Deep-sea gigantism" }

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