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Acid rain is rain or any other form of precipitation that is unusually acidic, meaning that it has elevated levels of hydrogen ions (low pH). Most water, including drinking water, has a neutral pH that exists between 6.5 and 8.5, but acid rain has a pH level lower than this and ranges from 4–5 on average. The more acid...	{ "page_id": 3263, "title": "Acid rain" }
eruptions. == Definition == "Acid rain" is rain with a pH less than 5. "Clean" or unpolluted rain has a pH greater than 5 but still less than pH = 7 owing to the acidity caused by carbon dioxide acid according to the following reactions: H2O + CO2 ⇌ H2CO3 H2O + H2CO3 ⇌ HCO−3 + H3O+ A variety of natural and human-made s...	{ "page_id": 3263, "title": "Acid rain" }
scientist Svante Odén, who had drawn widespread attention to Europe's acid rain problem in popular newspapers and wrote a landmark paper on the subject in 1968. === In the United States === The earliest report about acid rain in the United States came from chemical evidence gathered from Hubbard Brook Valley; public aw...	{ "page_id": 3263, "title": "Acid rain" }
impact of acid precipitation on freshwater and terrestrial ecosystems. NAPAP also assessed the effects of acid rain on historical buildings, monuments, and building materials. It also funded extensive studies on atmospheric processes and potential control programs. From the start, policy advocates from all sides attemp...	{ "page_id": 3263, "title": "Acid rain" }
and stated that it was withheld after the House's vote because it was not ready to be published. In 1991, the US National Acid Precipitation Assessment Program (NAPAP) provided its first assessment of acid rain in the United States. It reported that 5% of New England Lakes were acidic, with sulfates being the most comm...	{ "page_id": 3263, "title": "Acid rain" }
another. CAIR will permanently cap emissions of SO2 and NOx in the eastern United States. When fully implemented, CAIR will reduce SO2 emissions in 28 eastern states and the District of Columbia by over 70% and NOx emissions by over 60% from 2003 levels. Overall, the program's cap and trade program has been successful ...	{ "page_id": 3263, "title": "Acid rain" }
in an acid-rain awareness-raising campaign. The volunteers collected samples, checked for acidity, and reported to the organization. The information was then used to demonstrate the full extent of the phenomenon." === In Canada === Canadian Harold Harvey was among the first to research a "dead" lake. In 1971, he and R....	{ "page_id": 3263, "title": "Acid rain" }
1991. In 1998, all federal, provincial, and territorial Ministers of Energy and Environment signed The Canada-Wide Acid Rain Strategy for Post-2000, which was designed to protect lakes that are more sensitive than those protected by earlier policies. === In India === Acid rain was first reported in Mumbai (then Bombay)...	{ "page_id": 3263, "title": "Acid rain" }
the oceans. The major biological source of sulfur compounds is dimethyl sulfide. Nitric acid in rainwater is an important source of fixed nitrogen for plant life, and is also produced by electrical activity in the atmosphere such as lightning. Acidic deposits have been detected in glacial ice thousands of years old in ...	{ "page_id": 3263, "title": "Acid rain" }
humans comes hair loss, low urinary pH, severe mineral imbalances, constipation, and many cases of chronic disorders like Fibromyalgia and Basal Carcinoma. == Chemical process == Combustion of fuels and smelting of some ores produce sulfur dioxide and nitric oxides. They are converted into sulfuric acid and nitric acid...	{ "page_id": 3263, "title": "Acid rain" }
content, and alteration of biogeochemical processes. Both the lower pH and higher aluminium concentrations in surface water that occur as a result of acid rain can cause damage to fish and other aquatic animals. At pH lower than 5 most fish eggs will not hatch and lower pH can kill adult fish. As lakes and rivers becom...	{ "page_id": 3263, "title": "Acid rain" }
as sugar maple (Acer saccharum). Soil acidification Impacts of acidic water and soil acidification on plants could be minor or in most cases major. Most minor cases which do not result in fatality of plant life can be attributed to the plants being less susceptible to acidic conditions and/or the acid rain being less p...	{ "page_id": 3263, "title": "Acid rain" }
for its own survival or oxygen for the survival of aerobic organisms, which affects most species on Earth and ultimately ends the purpose of the plant's existence. === Forests and other vegetation === Adverse effects may be indirectly related to acid rain, like the acid's effects on soil (see above) or high concentrati...	{ "page_id": 3263, "title": "Acid rain" }
acidic fog and clouds can deplete nutrients from tree foliage, leading to discolored or dead leaves and needles. This depletion compromises the trees' ability to absorb sunlight, weakening them and diminishing their capacity to endure cold conditions. Other plants can also be damaged by acid rain, but the effect on foo...	{ "page_id": 3263, "title": "Acid rain" }
the ocean. === Human health effects === Acid rain can negatively impact human health, especially when people breathe in particles released from acid rain. The effects of acid rain on human health are complex and may be seen in several ways, such as respiratory issues for long-term exposure and indirect exposure through...	{ "page_id": 3263, "title": "Acid rain" }
sulfuric acid has been known to burn the mouth and throat, erode a hole in the stomach, burns when it comes into contact with skin, make your eyes weep if it gets into them, and mortality. ==== Federal Government's recommendation ==== ===== Nitrogen Dioxides ===== A 25 parts per million (ppm) maximum for nitric oxide i...	{ "page_id": 3263, "title": "Acid rain" }
+ CO2 (g) + H2O (l) The effects of this are commonly seen on old gravestones, where acid rain can cause the inscriptions to become completely illegible. Acid rain also increases the corrosion rate of metals, in particular iron, steel, copper and bronze. == Affected areas == Places significantly impacted by acid rain ar...	{ "page_id": 3263, "title": "Acid rain" }
power production. Vehicle emissions control reduces emissions of nitrogen oxides from motor vehicles. === International treaties === International treaties on the long-range transport of atmospheric pollutants have been agreed upon by western countries for some time now. Beginning in 1979, European countries convened i...	{ "page_id": 3263, "title": "Acid rain" }
pollutant it emits. Operators can then install pollution control equipment, and sell portions of their emissions allowances they no longer need for their own operations, thereby recovering some of the capital cost of their investment in such equipment. The intention is to give operators economic incentives to install p...	{ "page_id": 3263, "title": "Acid rain" }
more than their party affiliation.... Change can happen – but not on its own. We need to drive it." (p. 76.) == External links == National Acid Precipitation Assessment Program Report – a 98-page report to Congress (2005) Acid rain for schools Acid rain for schools – Hubbard Brook United States Environmental Protection...	{ "page_id": 3263, "title": "Acid rain" }
Marcus Manuel Hartog (19 August 1851, London – 21 January 1924, Paris) was an English educator, natural historian, philosopher of biology and zoologist in Cork, Ireland. He contributed to multiple volumes of the Cambridge Natural History. == Life == Hartog was born in London 1851, the second son of the Professor Alphon...	{ "page_id": 20516033, "title": "Marcus Hartog" }
== Hartog contributed articles to the Dictionary of National Biography and the Encyclopædia Britannica, as well as writing many articles for scientific journals. Problems of Life and Reproduction (1913) The True Mechanism of Mitosis (1914) == Family == In 1874 in Paris, France, Hartog married Blanche Levy, daughter of ...	{ "page_id": 20516033, "title": "Marcus Hartog" }
Characteristic samples is a concept in the field of grammatical inference, related to passive learning. In passive learning, an inference algorithm I {\displaystyle I} is given a set of pairs of strings and labels S {\displaystyle S} , and returns a representation R {\displaystyle R} that is consistent with S {\display...	{ "page_id": 77139138, "title": "Characteristic samples" }
correctly labeled words to the set in order to confuse the inference algorithm The inference algorithm I {\displaystyle I} gets the sample and computes a representation R ∈ R {\displaystyle R\in \mathbb {R} } consistent with the sample. The goal is that when the inference algorithm receives a characteristic sample for ...	{ "page_id": 77139138, "title": "Characteristic samples" }
's output on D {\displaystyle D} is a representation R {\displaystyle R} that recognizes L {\displaystyle L} . A Class of languages C {\displaystyle \mathbb {C} } is said to have charistaristic samples if every L ∈ C {\displaystyle L\in \mathbb {C} } has a characteristic sample. == Related Theorems == === Theorem === I...	{ "page_id": 77139138, "title": "Characteristic samples" }
there is a characteristic sample for L 1 {\displaystyle L_{1}} , S 1 {\displaystyle S_{1}} that is also consistent with L 2 {\displaystyle L_{2}} , we'll assume falsely that there exist a characteristic sample for L 2 {\displaystyle L_{2}} , S 2 {\displaystyle S_{2}} that is consistent with L 1 {\displaystyle L_{1}} . ...	{ "page_id": 77139138, "title": "Characteristic samples" }
L {\displaystyle L} by the teacher goes as follows. Firstly, by running a depth first search on a deterministic automaton A {\displaystyle A} recognizing L {\displaystyle L} , starting from its initial state, we get a suffix closed set of words, W {\displaystyle W} , ordered in shortlex order. From the fact above, we k...	{ "page_id": 77139138, "title": "Characteristic samples" }
and suffix s j {\displaystyle s_{j}} : If p i s j ∈ W → M i j = l ( p i s j ) {\displaystyle p_{i}s_{j}\in W\rightarrow M_{ij}=l(p_{i}s_{j})} else, M i j = 0 {\displaystyle M_{ij}=0} Now, we say row i {\displaystyle i} and t {\displaystyle t} are distinguishable if there exists an index j {\displaystyle j} such that M ...	{ "page_id": 77139138, "title": "Characteristic samples" }
function will be defined δ ( s , σ ) = s ′ {\displaystyle \delta (s,\sigma )=s'} , where s ′ {\displaystyle s'} is the element in Q {\displaystyle Q} that is indistinguishable from s σ {\displaystyle s\sigma } . === Other polynomially characterizable classes === Class of languages recognizable by multiplicity automaton...	{ "page_id": 77139138, "title": "Characteristic samples" }
A {\displaystyle A} Selects a representation R {\displaystyle R} of size n {\displaystyle n} from C {\displaystyle \mathbb {C} } T {\displaystyle T} computes a sample that is consistent with the language that R {\displaystyle R} recognize, of size bounded by p ( n ) {\displaystyle p(n)} and the strings in the sample bo...	{ "page_id": 77139138, "title": "Characteristic samples" }
sample computaed by the teacher, and the output of I {\displaystyle I} on every sample S ′ {\displaystyle S'} such that S ⊆ S ′ {\displaystyle S\subseteq S'} is equivalent to R {\displaystyle R} from the definition of characteristic sample. Assuming that C {\displaystyle \mathbb {C} } is semi-poly T / L {\displaystyle ...	{ "page_id": 77139138, "title": "Characteristic samples" }
Lysine iron agar or LIA is a differential media used to distinguish bacteria that are able to decarboxylate lysine and/or produce hydrogen sulfide from those that cannot. This test is particularly useful for distinguishing different Gram-negative bacilli—especially among the Enterobacteriaceae. == Composition == A lite...	{ "page_id": 33230017, "title": "Lysine iron agar" }
Photoinduced electron transfer (PET) is an excited state electron transfer process by which an excited electron is transferred from donor to acceptor. Due to PET a charge separation is generated, i.e., redox reaction takes place in excited state (this phenomenon is not observed in Dexter electron transfer). == Breadth ...	{ "page_id": 12979395, "title": "Photoinduced electron transfer" }
by delivery of the electron to a lower energy conductor attached to the p/n junction or into an electron transport chain. In this case some of the energy can be captured to do work. If the electron is not kinetically isolated thermodynamics will take over and the products will react with each other to regenerate the gr...	{ "page_id": 12979395, "title": "Photoinduced electron transfer" }
Bolesatine is a glycoprotein isolated from the Rubroboletus satanas (Boletus satanas Lenz) mushroom which has a lectin function that is specific to the sugar binding site of D-galactose. It is a monomeric protein with a compact globular structure and is thermostable. One tryptophan can be found in its primary sequence ...	{ "page_id": 60820678, "title": "Bolesatine" }
Michael Osborne (born 1982) is an Australian academic and scientist who serves as a professor of machine learning at University of Oxford in the Machine Learning Research Group in the Department of Engineering Science. In 2016 he co-founded Mind Foundry, an artificial intelligence company, along with fellow professor S...	{ "page_id": 75238604, "title": "Michael Osborne (academic)" }
Programme on Technology and Employment in 2015. He is a Director of the EPSRC Centre for Doctoral Training in Autonomous Intelligent Machines and Systems. == References == == External links == Official homepage	{ "page_id": 75238604, "title": "Michael Osborne (academic)" }
An inverted pendulum is a pendulum that has its center of mass above its pivot point. It is unstable and falls over without additional help. It can be suspended stably in this inverted position by using a control system to monitor the angle of the pole and move the pivot point horizontally back under the center of mass...	{ "page_id": 265421, "title": "Inverted pendulum" }
movement of the neutral position of the float away from its original position. == Overview == A pendulum with its bob hanging directly below the support pivot is at a stable equilibrium point, where it remains motionless because there is no torque on the pendulum. If displaced from this position, it experiences a resto...	{ "page_id": 265421, "title": "Inverted pendulum" }
such as the Segway PT, the self-balancing hoverboard and the self-balancing unicycle. Another way that an inverted pendulum may be stabilized, without any feedback or control mechanism, is by oscillating the pivot rapidly up and down. This is called Kapitza's pendulum. If the oscillation is sufficiently strong (in term...	{ "page_id": 265421, "title": "Inverted pendulum" }
away from the vertical unstable equilibrium in the direction initially displaced, and the acceleration is inversely proportional to the length. Tall pendulums fall more slowly than short ones. Derivation using torque and moment of inertia: The pendulum is assumed to consist of a point mass, of mass m {\displaystyle m} ...	{ "page_id": 265421, "title": "Inverted pendulum" }
{\displaystyle \ell } pivoted on a horizontally moving base as shown in the adjacent image. The cart is restricted to linear motion and is subject to forces resulting in or hindering motion. === Essentials of stabilization === The essentials of stabilizing the inverted pendulum can be summarized qualitatively in three ...	{ "page_id": 265421, "title": "Inverted pendulum" }
feedback instability to produce a stable system is a feature that makes the mathematical analysis an interesting and challenging problem. === From Lagrange's equations === The equations of motion can be derived using Lagrange's equations. We refer to the drawing to the right where θ ( t ) {\displaystyle \theta (t)} is ...	{ "page_id": 265421, "title": "Inverted pendulum" }
M + m ) x ˙ 2 − m ℓ x ˙ θ ˙ cos ⁡ θ + 1 2 m ℓ 2 θ ˙ 2 . {\displaystyle T={\frac {1}{2}}\left(M+m\right){\dot {x}}^{2}-m\ell {\dot {x}}{\dot {\theta }}\cos \theta +{\frac {1}{2}}m\ell ^{2}{\dot {\theta }}^{2}.} The generalized coordinates of the system are θ {\displaystyle \theta } and x {\displaystyle x} , each has a g...	{ "page_id": 265421, "title": "Inverted pendulum" }
{\dot {\theta }}^{2}\sin \theta =F,} ℓ θ ¨ − g sin ⁡ θ = x ¨ cos ⁡ θ . {\displaystyle \ell {\ddot {\theta }}-g\sin \theta ={\ddot {x}}\cos \theta .} These equations are nonlinear, but since the goal of a control system would be to keep the pendulum upright, the equations can be linearized around θ ≈ 0 {\displaystyle \t...	{ "page_id": 265421, "title": "Inverted pendulum" }
Newton's equations give the reaction forces at the joint between the pendulum and the cart. These equations give rise to two equations for each body; one in the x-direction and the other in the y-direction. The equations of motion of the cart are shown below where the LHS is the sum of the forces on the body and the RH...	{ "page_id": 265421, "title": "Inverted pendulum" }
-\ell {\ddot {\theta }}\sin \theta ){\hat {y}}_{I}} Then, using Newton's second law, two equations can be written in the x-direction and the y-direction. Note that the reaction forces are positive as applied to the pendulum and negative when applied to the cart. This is due to Newton's third law. R x = m ( x ¨ + ℓ θ ˙ ...	{ "page_id": 265421, "title": "Inverted pendulum" }
typically noted as the x-coordinate of the body frame. In inertial coordinates this vector can be written using a simple 2-D coordinate transformation x ^ B = cos ⁡ θ x ^ I + sin ⁡ θ y ^ I {\displaystyle {\hat {x}}_{B}=\cos \theta {\hat {x}}_{I}+\sin \theta {\hat {y}}_{I}} The pendulum equation of motion written in vec...	{ "page_id": 265421, "title": "Inverted pendulum" }
of the equation is computed similarly by dotting x ^ B {\displaystyle {\hat {x}}_{B}} with the acceleration of the pendulum. The result (after some simplification) is shown below. m ( x ^ B ) T ( a → P / I ) = m ( x ¨ cos ⁡ θ − ℓ θ ¨ ) {\displaystyle m({\hat {x}}_{B})^{T}({\vec {a}}_{P/I})=m({\ddot {x}}\cos \theta -\el...	{ "page_id": 265421, "title": "Inverted pendulum" }
spherical ball all balance on a single point. === Kapitza's pendulum === An inverted pendulum in which the pivot is oscillated rapidly up and down can be stable in the inverted position. This is called Kapitza's pendulum, after Russian physicist Pyotr Kapitza who first analysed it. The equation of motion for a pendulum...	{ "page_id": 265421, "title": "Inverted pendulum" }
following differential equation is: θ ¨ − g ℓ sin ⁡ θ = − A ℓ ω 2 sin ⁡ ω t sin ⁡ θ . {\displaystyle {\ddot {\theta }}-{g \over \ell }\sin \theta =-{A \over \ell }\omega ^{2}\sin \omega t\sin \theta .} This equation does not have elementary closed-form solutions, but can be explored in a variety of ways. It is closely ...	{ "page_id": 265421, "title": "Inverted pendulum" }
on one leg puts additional demands on this system. Certain diseases and alcohol or drug intoxication can interfere with this reflex, causing dizziness and disequilibration, an inability to stand upright. A field sobriety test used by police to test drivers for the influence of alcohol or drugs, tests this reflex for im...	{ "page_id": 265421, "title": "Inverted pendulum" }
Cart and Pole Control Task	{ "page_id": 265421, "title": "Inverted pendulum" }
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants are frequently added to industrial products, such as polymers, fuels, and lubricants, to extend their usable lifetimes. Foo...	{ "page_id": 3277, "title": "Antioxidant" }
consumption. However, it was the identification of vitamins C and E as antioxidants that revolutionized the field and led to the realization of the importance of antioxidants in the biochemistry of living organisms. The possible mechanisms of action of antioxidants were first explored when it was recognized that a subs...	{ "page_id": 3277, "title": "Antioxidant" }
drying. Metals catalyse oxidation. Some fatty foods such as olive oil are partially protected from oxidation by their natural content of antioxidants. Fatty foods are sensitive to photooxidation, which forms hydroperoxides by oxidizing unsaturated fatty acids and ester. Exposure to ultraviolet (UV) radiation can cause ...	{ "page_id": 3277, "title": "Antioxidant" }
(ROO•), thus preventing chain reactions that lead to polymer degradation. Phenolics: They are more specifically "hindered phenols", which means a bulky group (typically a tert-butyl) is put near the phenol OH. Examples: butylated hydroxytoluene, 2,4-dimethyl-6-tert-butylphenol, para tertiary butyl phenol, 2,6-di-tert-b...	{ "page_id": 3277, "title": "Antioxidant" }
sediment, sewage, river water and wastewater. They are synthesized from phenolic compounds and include 2,6-di-tert-butyl-4-methylphenol (BHT), 2,6-di-tert-butyl-p-benzoquinone (BHT-Q), 2,4-di-tert-butyl-phenol (DBP) and 3-tert-butyl-4-hydroxyanisole (BHA). BHT can cause hepatotoxicity and damage to the endocrine system...	{ "page_id": 3277, "title": "Antioxidant" }
reversed by DNA repair mechanisms, while damage to proteins causes enzyme inhibition, denaturation, and protein degradation. The use of oxygen as part of the process for generating metabolic energy produces reactive oxygen species. In this process, the superoxide anion is produced as a by-product of several steps in th...	{ "page_id": 3277, "title": "Antioxidant" }
present within cells, while others such as uric acid are more systemically distributed (see table below). Some antioxidants are only found in a few organisms, and can be pathogens or virulence factors. The interactions between these different antioxidants may be synergistic and interdependent. The action of one antioxi...	{ "page_id": 3277, "title": "Antioxidant" }
as high as 285 μmol/L. ==== Vitamin C ==== Ascorbic acid or vitamin C, an oxidation-reduction (redox) catalyst found in both animals and plants, can reduce, and thereby neutralize, reactive oxygen species such as hydrogen peroxide. In addition to its direct antioxidant effects, ascorbic acid is also a substrate for the...	{ "page_id": 3277, "title": "Antioxidant" }
produces oxidised α-tocopheroxyl radicals that can be recycled back to the active reduced form through reduction by other antioxidants, such as ascorbate, retinol or ubiquinol. This is in line with findings showing that α-tocopherol, but not water-soluble antioxidants, efficiently protects glutathione peroxidase 4 (GPX...	{ "page_id": 3277, "title": "Antioxidant" }
the chemical antioxidants, cells are protected against oxidative stress by an interacting network of antioxidant enzymes. Here, the superoxide released by processes such as oxidative phosphorylation is first converted to hydrogen peroxide and then further reduced to give water. This detoxification pathway is the result...	{ "page_id": 3277, "title": "Antioxidant" }
This protein is localized to peroxisomes in most eukaryotic cells. Catalase is an unusual enzyme since, although hydrogen peroxide is its only substrate, it follows a ping-pong mechanism. Here, its cofactor is oxidised by one molecule of hydrogen peroxide and then regenerated by transferring the bound oxygen to a secon...	{ "page_id": 3277, "title": "Antioxidant" }
by the action of thioredoxin reductase, using NADPH as an electron donor. The glutathione system includes glutathione, glutathione reductase, glutathione peroxidases, and glutathione S-transferases. This system is found in animals, plants and microorganisms. Glutathione peroxidase is an enzyme containing four selenium-...	{ "page_id": 3277, "title": "Antioxidant" }
which are high in plant-based diets. Calcium and iron deficiencies are not uncommon in diets in developing countries where less meat is eaten and there is high consumption of phytic acid from beans and unleavened whole grain bread. However, germination, soaking, or microbial fermentation are all household strategies th...	{ "page_id": 3277, "title": "Antioxidant" }
in elderly or vulnerable populations. === Exercise and muscle soreness === A 2017 review showed that taking antioxidant dietary supplements before or after exercise is unlikely to produce a noticeable reduction in muscle soreness after a person exercises. == Levels in food == Antioxidant vitamins are found in vegetable...	{ "page_id": 3277, "title": "Antioxidant" }
were withdrawn in 2012 as biologically irrelevant to human health, referring to an absence of physiological evidence for polyphenols having antioxidant properties in vivo. Consequently, the ORAC method, derived only from in vitro experiments, is no longer considered relevant to human diets or biology, as of 2010. Alter...	{ "page_id": 3277, "title": "Antioxidant" }
Activated alumina is manufactured from aluminium hydroxide by dehydroxylating it in a way that produces a highly porous material; this material can have a surface area significantly over 200 m2/g. The compound is used as a desiccant (to keep things dry by adsorbing water from the air) and as a filter of fluoride, arsen...	{ "page_id": 1969364, "title": "Activated alumina" }
cause fluorosis. A study from the Harvard school of Public Health found exposure to high levels of fluoride as a child correlated with lower IQ. Activated alumina filters can easily reduce fluoride levels from 10 ppm to less than 1 ppm. The amount of fluoride leached from the water being filtered depends on how long th...	{ "page_id": 1969364, "title": "Activated alumina" }
prevent oil generated by rotary vane pumps from back streaming into the system. A baffle of activated alumina can also replace the refrigerated trap often required for diffusion pumps, though this is rarely used. === Biomaterial === Its mechanical properties and non-reactivity in the biological environment allow it to ...	{ "page_id": 1969364, "title": "Activated alumina" }
In condensed matter physics, second sound is a quantum mechanical phenomenon in which heat transfer occurs by wave-like motion, rather than by the more usual mechanism of diffusion. Its presence leads to a very high thermal conductivity. It is known as "second sound" because the wave motion of entropy and temperature i...	{ "page_id": 10685654, "title": "Second sound" }
sound. The second sound thus behaves as oscillations of the local number of quasiparticles (or of the local energy carried by these particles). Contrary to the normal sound where energy is related to pressure and temperature, in a crystal the local energy density is purely a function of the temperature. In this sense, ...	{ "page_id": 10685654, "title": "Second sound" }
∂ ρ ) S ≈ ( ∂ p / ∂ ρ ) T {\displaystyle c=(\partial p/\partial \rho )_{S}\approx (\partial p/\partial \rho )_{T}} is the ordinary (or first) sound speed. == In other media == Second sound has been observed in solid 4He and 3He, and in some dielectric solids such as Bi in the temperature range of 1.2 to 4.0 K with a ve...	{ "page_id": 10685654, "title": "Second sound" }
Sinyan Shen, Surface Second Sound in Superfluid Helium. PhD Dissertation (1973). http://adsabs.harvard.edu/abs/1973PhDT.......142S V. Peshkov, "'Second Sound' in Helium II," J. Phys. (Moscow) 8, 381 (1944) U. Piram, "Numerical investigation of second sound in liquid helium," Dipl.-Ing. Dissertation (1991). Retrieved on...	{ "page_id": 10685654, "title": "Second sound" }
Methylfentanyl may refer to: 3-Methylfentanyl α-Methylfentanyl β-Methylfentanyl	{ "page_id": 36375767, "title": "Methylfentanyl" }
In mathematics and physics, Herglotz's variational principle, named after German mathematician and physicist Gustav Herglotz, is an extension of the Hamilton's principle, where the Lagrangian L explicitly involves the action S {\displaystyle S} as an independent variable, and S {\displaystyle S} itself is represented a...	{ "page_id": 79891671, "title": "Herglotz's variational principle" }
:= S ( t 1 ) {\displaystyle S_{1}:=S(t_{1})} is a well defined number which is determined by the curve q ( t ) {\displaystyle {\boldsymbol {q}}(t)} . Herglotz's variation problem aims to minimize S 1 {\displaystyle S_{1}} over the family of curves q ( t ) {\displaystyle {\boldsymbol {q}}(t)} with fixed value q 0 {\disp...	{ "page_id": 79891671, "title": "Herglotz's variational principle" }
∂ S ∂ L ∂ q ˙ {\textstyle {\frac {\partial L}{\partial S}}{\frac {\partial L}{\partial {\dot {\boldsymbol {q}}}}}} that can describe the dissipation of the system. == Derivation == In order to solve this minimization problem, we impose a variation δ q {\displaystyle \delta {\boldsymbol {q}}} on q {\displaystyle {\bolds...	{ "page_id": 79891671, "title": "Herglotz's variational principle" }
, u ( t 0 ) = 1. {\displaystyle {\dot {\mu }}(t)=-\mu (t){\frac {\partial L}{\partial S}},\quad u(t_{0})=1.} By multiplying μ ( t ) {\displaystyle \mu (t)} on both sides of the equation of δ S ˙ {\displaystyle \delta {\dot {S}}} and moving the term μ ( t ) ∂ L ∂ S δ S ( t ) {\textstyle \mu (t){\frac {\partial L}{\parti...	{ "page_id": 79891671, "title": "Herglotz's variational principle" }
∂ q ˙ δ q ˙ ( t ) ) d t {\displaystyle \mu (t_{1})\delta S_{1}-\mu (t_{0})\delta S_{0}=\int _{t_{0}}^{t_{1}}\mu (t)\left({\frac {\partial L}{\partial {\boldsymbol {q}}}}\delta {\boldsymbol {q}}(t)+{\frac {\partial L}{\partial {\dot {\boldsymbol {q}}}}}\delta {\dot {\boldsymbol {q}}}(t)\right)\mathrm {d} t} where the δ ...	{ "page_id": 79891671, "title": "Herglotz's variational principle" }
t ) d t − ∫ t 0 t 1 d d t ( μ ( t ) ∂ L ∂ q ˙ ) δ q ( t ) d t = ∫ t 0 t 1 μ ( t ) ∂ L ∂ q δ q ( t ) d t − ∫ t 0 t 1 ( μ ˙ ( t ) ∂ L ∂ q ˙ + μ ( t ) d d t ∂ L ∂ q ˙ ) δ q ( t ) d t = ∫ t 0 t 1 μ ( t ) ∂ L ∂ q δ q ( t ) d t − ∫ t 0 t 1 ( − μ ( t ) ∂ L ∂ S ∂ L ∂ q ˙ + μ ( t ) d d t ∂ L ∂ q ˙ ) δ q ( t ) d t = ∫ t 0 t 1 μ ...	{ "page_id": 79891671, "title": "Herglotz's variational principle" }
t}}\left(\mu (t){\frac {\partial L}{\partial {\dot {\boldsymbol {q}}}}}\right)\delta {\boldsymbol {q}}(t)\mathrm {d} t\\=&\int _{t_{0}}^{t_{1}}\mu (t){\frac {\partial L}{\partial {\boldsymbol {q}}}}\delta {\boldsymbol {q}}(t)\mathrm {d} t-\int _{t_{0}}^{t_{1}}\left({\dot {\mu }}(t){\frac {\partial L}{\partial {\dot {\b...	{ "page_id": 79891671, "title": "Herglotz's variational principle" }
where γ {\displaystyle \gamma } is the damping coefficient. == References ==	{ "page_id": 79891671, "title": "Herglotz's variational principle" }
The hydrogen hypothesis is a model proposed by William F. Martin and Miklós Müller in 1998 that describes a possible way in which the mitochondrion arose as an endosymbiont within a prokaryotic host in the archaea, giving rise to a symbiotic association of two cells from which the first eukaryotic cell could have arise...	{ "page_id": 593115, "title": "Hydrogen hypothesis" }
the hydrogen hypothesis, this specific prediction has been tested many times and found to be in agreement with observation. In 2015, the discovery and placement of the Lokiarchaeota (an archaeal lineage possessing an expanded genetic repertoire including genes involved in membrane remodeling and actin cytoskeletal stru...	{ "page_id": 593115, "title": "Hydrogen hypothesis" }
A glacial relict is a population of a species that was common in the Northern Hemisphere prior to the onset of glaciation in the late Tertiary that was forced by climate change to retreat into refugia when continental ice sheets advanced. They are typically cold-adapted species with a distribution restricted to regions...	{ "page_id": 60951772, "title": "Glacial relict" }
it was unable to survive - it likely originally dispersed as seeds floating down the Altamaha River, but due to the nature of rivers, it was unable to make the reverse journey to cooler upland climes and survive rising temperatures. This species was the subject of a number of enthusiastic searches to locate potential w...	{ "page_id": 60951772, "title": "Glacial relict" }
The toroidal ring model, known originally as the Parson magneton or magnetic electron, is a physical model of subatomic particles. It is also known as the plasmoid ring, vortex ring, or helicon ring. This physical model treated electrons and protons as elementary particles, and was first proposed by Alfred Lauck Parson...	{ "page_id": 13372642, "title": "Toroidal ring model" }
around the ring an integer number of times as it proceeded around the ring. This requirement was thought to account for "quantum" values of angular momentum and radiation. Chirality demanded the number of fibers to be odd, probably three, like a rope. The helicity of the twist, was thought to distinguish the electron f...	{ "page_id": 13372642, "title": "Toroidal ring model" }
paper, which incidentally calculated both the Planck constant h and the Boltzmann constant kB, suggested that something in the "resonators" themselves provided these discrete frequencies. Numerous theories about the structure of the atom developed in the wake of all the new information, of which the 1913 model of Niels...	{ "page_id": 13372642, "title": "Toroidal ring model" }
could have an intrinsic quantum spin, and also a magnetic moment. The highly successful modern theory, Standard Model of particle physics describes a pointlike electron with an intrinsic spin and magnetic moment. On the other hand, the usual assertion that an electron is pointlike may be conventionally associated only ...	{ "page_id": 13372642, "title": "Toroidal ring model" }
of the Compton size with a toroidal structure with the outer radius of the Compton size and the inner radius of the Cartan size (10−27 m) in the Einstein–Cartan theory of gravity. == References == == Further reading == David L. Bergman, J. Paul Wesley ; Spinning Charged Ring Model of Electron Yielding Anomalous Magneti...	{ "page_id": 13372642, "title": "Toroidal ring model" }
100% English is a Channel 4 television programme shown in November 2006 in the United Kingdom. It looked at the genetic makeup of English people who considered themselves to be ethnically English and found that while all had an ethnic makeup similar to people of European descent, a minority discovered genetic markers f...	{ "page_id": 7998691, "title": "100% English" }
PRAC (Probabilistic Action Cores) is an interpreter for natural-language instructions for robotic applications developed at the Institute for Artificial Intelligence at the University of Bremen, Germany, and is supported in parts by the European Commission and the German Research Foundation (DFG). == Goals == The ultim...	{ "page_id": 53480676, "title": "Probabilistic Action Cores" }
Tissue growth is the process by which a tissue increases its size. In animals, tissue growth occurs during embryonic development, post-natal growth, and tissue regeneration. The fundamental cellular basis for tissue growth is the process of cell proliferation, which involves both cell growth and cell division occurring...	{ "page_id": 51514596, "title": "Tissue growth" }
skeleton or the internal mammalian organs intestine, pancreas, kidney or brain, it remains unclear how developmental gene regulatory networks encoded in the genome lead to organs of such different sizes and proportions. === Hormonal control of tissue growth in the entire animal body === Although different animal tissue...	{ "page_id": 51514596, "title": "Tissue growth" }
The minimum bactericidal concentration (MBC) is the lowest concentration of an antibacterial agent required to kill a particular bacterium. It can be determined from broth dilution minimum inhibitory concentration (MIC) tests by subculturing to agar plates that do not contain the test agent. The MBC is identified by de...	{ "page_id": 10816739, "title": "Minimum bactericidal concentration" }
A lamella (pl.: lamellae) is a small plate or flake, from the Latin, and may also refer to collections of fine sheets of material held adjacent to one another in a gill-shaped structure, often with fluid in between though sometimes simply a set of "welded" plates. The term is used in biological contexts for thin membra...	{ "page_id": 1641702, "title": "Lamella (materials)" }
condition. Lamellar Ichthyosis often presents with a "colloidal" membrane at birth. It is characterized by generalized dark scaling. The term lamella(e) is used in the flooring industry to describe the finished top-layer of an engineered wooden floor. For example, an engineered walnut floor will have several layers of ...	{ "page_id": 1641702, "title": "Lamella (materials)" }

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