Split (1)

train · 253k rows

page_content stringlengths 51 3.15k
Pressure Exchanger Reverse osmosis Pressure_Exchanger > Reverse osmosis Pressure exchangers save energy in these systems by reducing the load on the high pressure pump. In a seawater RO system operating at a 40% membrane water recovery rate, the ERD supplies 60% of the membrane feed flow. Energy is consumed by the circulation pump, however, because this pump merely circulates and does not pressurize water, its energy consumption is almost negligible: less than 3% of the energy consumed by the high pressure pump. Therefore, nearly 60% of the membrane feed flow is pressurized with almost no energy input.
208 (number) Summary 208_(number) 208 (two hundred eight) is the natural number following 207 and preceding 209. 208 is a practical number, a tetranacci number, a rhombic matchstick number, a happy number, and a member of Aronson's sequence. There are exactly 208 five-bead necklaces drawn from a set of beads with four colors, and 208 generalized weak orders on three labeled points. == References ==
Quasi-experiment Design Quasi-experiment > Design Then the actual experiment is done with post test results recorded. This data can be compared as part of the study or the pre-test data can be included in an explanation for the actual experimental data. Quasi experiments have independent variables that already exist such as age, gender, eye color.
Paraffin oxidation Mechanism Paraffin_oxidation > Mechanism This produces, among other things, an alkyl radical, which forms with oxygen peroxo radikals. This forms by abstraction of a hydrogen atom from another molecule paraffin a new alkyl radical and a hydroperoxide. The mechanism of the reaction follows the following scheme: As a first step the formation of a hydroperoxide occurs, which degrades as the main reaction into water and a ketone. As a side reaction secondary alcohols are formed according to the following reaction: == References ==
Microwave power meter Thermal Microwave_power_meter > Sensor technologies > Thermal Thermocouple sensors often require a reference DC or microwave power source for calibration before measuring; this can be built into the power meter. Thermistor-based power sensors such as the Keysight 8478B are generally only used in situations where their excellent linearity is important, as they are both much slower and have a smaller dynamic range than either thermocouple or diode-based sensors. Thermistor-based power sensors are still the sensor of choice for power transfer standards because of their DC power substitution capability. Other thermal sensing technologies include microwave calorimeters and bolometers, and quasi-optic pulsed microwave sensors.
Method of moments (statistics) Summary Method_of_moments_(statistics) The number of such equations is the same as the number of parameters to be estimated. Those equations are then solved for the parameters of interest. The solutions are estimates of those parameters. The method of moments was introduced by Pafnuty Chebyshev in 1887 in the proof of the central limit theorem. The idea of matching empirical moments of a distribution to the population moments dates back at least to Pearson.
Laplace transforms s-domain equivalent circuits and impedances Laplace_transforms > s-domain equivalent circuits and impedances The sources are put in if there are initial conditions on the circuit elements. For example, if a capacitor has an initial voltage across it, or if the inductor has an initial current through it, the sources inserted in the s-domain account for that. The equivalents for current and voltage sources are simply derived from the transformations in the table above.
Immune network theory Relevance for understanding HIV pathogenesis Immune_network_theory > Relevance for understanding HIV pathogenesis At that point, the adaptive immune system is completely compromised and AIDS ensues. Hence in this model, the onset of AIDS is primarily an auto-immune reaction triggered by the cross-reaction of anti-HIV antibodies with T regulatory cells.
Cohomology Axioms and generalized cohomology theories Cohomology > Axioms and generalized cohomology theories In more detail, a generalized cohomology theory is a sequence of contravariant functors hi (for integers i) from the category of CW-pairs to the category of abelian groups, together with a natural transformation d: hi(A) → hi+1(X,A) called the boundary homomorphism (writing hi(A) for hi(A,∅)). The axioms are: Homotopy: Homotopic maps induce the same homomorphism on cohomology. Exactness: Each pair (X,A) induces a long exact sequence in cohomology, via the inclusions f: A → X and g: (X,∅) → (X,A): Excision: If X is the union of subcomplexes A and B, then the inclusion f: (A,A∩B) → (X,B) induces an isomorphism for every i. Additivity: If (X,A) is the disjoint union of a set of pairs (Xα,Aα), then the inclusions (Xα,Aα) → (X,A) induce an isomorphism to the product group: for every i.A spectrum determines both a generalized homology theory and a generalized cohomology theory.
Seasonal flu Notable occurrences Seasonal_flu > Notable occurrences Seasonal epidemics of influenza can be severe. Some can even rival pandemics in terms of excess mortality. In fact, it is not so much mortality that distinguishes seasonal epidemics from pandemics but rather the extent to which the disease has spread, though the reasons behind this distinction between epidemic and pandemic, as well as the geographic variability observed within individual flu seasons, remain poorly understood. As such, some flu seasons are particularly notable in terms of severity.
Solar Electric Light Fund Expanding Services Solar_Electric_Light_Fund > History > Expanding Services Beginning in 2000, SELF embarked on its next generation of projects that would seek to harness solar energy for things such as advancing water pumping and purification, purveying electrification to rural schools and health clinics, providing power to small businesses and micro-enterprises, and facilitating communication access. The first opportunity to fulfill this expanded vision was found in South Africa, where SELF had been working on a project to install solar home systems in the Valley of a Thousand Hills, in the province of KwaZulu-Natal. SELF installed a 1.5-kilowatt solar array, which generated enough electricity to power approximately 20 PCs donated by Dell Computers and a small satellite dish that delivered Internet access to Myeka High School. This was the first solar-powered computer lab built in South Africa, and the pass rate at Myeka High School jumped from 30 percent to 70 percent within a year and a half of installation.
Prosecutor's fallacy Findings in psychology Prosecutor's_fallacy > Findings in psychology Using natural frequencies simplifies the inference because the required mathematical operation can be performed on natural numbers, instead of normalized fractions (i.e., probabilities), because it makes the high number of false positives more transparent, and because natural frequencies exhibit a "nested-set structure".Not every frequency format facilitates Bayesian reasoning. Natural frequencies refer to frequency information that results from natural sampling, which preserves base rate information (e.g., number of drunken drivers when taking a random sample of drivers). This is different from systematic sampling, in which base rates are fixed a priori (e.g., in scientific experiments). In the latter case it is not possible to infer the posterior probability p (drunk \| positive test) from comparing the number of drivers who are drunk and test positive compared to the total number of people who get a positive breathalyzer result, because base rate information is not preserved and must be explicitly re-introduced using Bayes' theorem.
Web3 Concept Web3 > Concept Specific visions for Web3 differ, and the term has been described by Olga Kharif as "hazy", but they revolve around the idea of decentralization and often incorporate blockchain technologies, such as various cryptocurrencies and non-fungible tokens (NFTs). Kharif has described Web3 as an idea that "would build financial assets, in the form of tokens, into the inner workings of almost anything you do online". A policy brief published by the Bennett Institute for Public Policy at the University of Cambridge defined Web3 as "the putative next generation of the web’s technical, legal, and payments infrastructure—including blockchain, smart contracts and cryptocurrencies." According to Liu, Zhuotao, et al (2021), three fundamental architectural enablers of Web3 were identified as a combination of decentralized or federated platforms, secured interoperability, and verifiable computing through distributed ledger technologies.Some visions are based around the concept of decentralized autonomous organizations (DAOs).
Energy harvesting devices Photovoltaic Power_stealing > Energy sources > Photovoltaic The dyes absorb light much like chlorophyll does in plants. Electrons released on impact escape to the layer of TiO2 and from there diffuse, through the electrolyte, as the dye can be tuned to the visible spectrum much higher power can be produced. At 200 lux a DSSC can provide over 10 μW per cm2.
Ground level ozone Formation Ground_level_ozone > Formation The majority of tropospheric ozone formation occurs when nitrogen oxides (NOx), carbon monoxide (CO), and volatile organic compounds (VOCs), react in the atmosphere in the presence of sunlight, specifically the UV spectrum. NOx, CO, and VOCs are considered ozone precursors. Motor vehicle exhaust, industrial emissions, and chemical solvents are the major anthropogenic sources of these ozone precursors.
Gliding ant Summary Gliding_ant The ant will first randomly descend 3 or 4 metres (10 or 13 ft) in free fall, then visually lock on to the tree trunk it wishes to land on. The glide ant then, while exhibiting a sort of parachuting behaviour to slow its fall, uses its flattened head, hind legs and abdomen like wings or a parachute to make a rapid adjustment to point its abdomen (or head) towards the tree trunk. The ant then turns upside down and lands on the trunk, head facing the earth.
Cholesterol 7α-hydroxylase Specificity Cholesterol_7_alpha-hydroxylase > Enzymatic mechanism > Specificity One feature of enzymes is their high specificity. They are specific on a singular substrate, reaction or both together, that means, that the enzymes can catalyze all reactions wherein the substrate can experience. The enzyme cholesterol 7 alpha hydroxylase catalyzes the reaction that converts cholesterol into cholesterol 7 alpha hydroxylase reducing and oxidizing that molecule.
Eikonal equation Mathematical description Eikonal_equation > Mathematical description In the geometrical optics case, this means that wavefronts cross. We can solve the eikonal equation using the method of characteristics. One must impose the "non-characteristic" hypothesis ∂ p 1 H ( x , p ) ≠ 0 {\displaystyle \partial _{p_{1}}H(x,p)\neq 0} along the initial hypersurface x = ( 0 , x ′ ) {\displaystyle x=(0,x')} , where H = H(x,p) and p = (p1,...,pn) is the variable that gets replaced by ∇u.
Entropy (order and disorder) Overview Entropy_(order_and_disorder) > Overview Similarly, in a gas, the order is perfect and the measure of entropy of the system has its lowest value when all the molecules are in one place, whereas when more points are occupied the gas is all the more disorderly and the measure of the entropy of the system has its largest value.In systems ecology, as another example, the entropy of a collection of items comprising a system is defined as a measure of their disorder or equivalently the relative likelihood of the instantaneous configuration of the items. Moreover, according to theoretical ecologist and chemical engineer Robert Ulanowicz, “that entropy might provide a quantification of the heretofore subjective notion of disorder has spawned innumerable scientific and philosophical narratives.” In particular, many biologists have taken to speaking in terms of the entropy of an organism, or about its antonym negentropy, as a measure of the structural order within an organism.The mathematical basis with respect to the association entropy has with order and disorder began, essentially, with the famous Boltzmann formula, S = k B ln ⁡ W {\displaystyle S=k_{\mathrm {B} }\ln W\!} , which relates entropy S to the number of possible states W in which a system can be found.
Factorial number system Definition Factorial_number_system > Definition + 1×1! + 0×0! = ((((3×5 + 4)×4 + 1)×3 + 0)×2 + 1)×1 + 0 = 46310.
Signal (software) Features Signal_(software) > Features The platform also supports group messaging. All communication sessions between Signal users are automatically end-to-end encrypted (the encryption keys are generated and stored on the devices, and not on servers). To verify that a correspondent is really the person that they claim to be, Signal users can compare key fingerprints (or scan QR codes) out-of-band.
Walrasian equilibrium Indivisible items Walrasian_equilibrium > Examples > Indivisible items In this case it is more difficult to find an equilibrium (see below). A possible equilibrium is that Alice buys the horse for 5 and Bob buys the car for 7. This is an equilibrium since Bob wouldn't like to pay 5 for the horse which will give him only 4 additional utility, and Alice wouldn't like to pay 7 for the car which will give her only 1 additional utility.
Turbofan engine Geared fan Turbofan_engine > Turbofan configurations > Geared fan As bypass ratio increases, the fan blade tip speed increases relative to the LPT blade speed. This will reduce the LPT blade speed, requiring more turbine stages to extract enough energy to drive the fan. Introducing a (planetary) reduction gearbox, with a suitable gear ratio, between the LP shaft and the fan enables both the fan and LP turbine to operate at their optimum speeds. Examples of this configuration are the long-established Garrett TFE731, the Honeywell ALF 502/507, and the recent Pratt & Whitney PW1000G.
Saturated set Properties Saturated_set > Properties {\displaystyle X.} If Y {\displaystyle Y} is also a topological space then f: ( X , τ ) → Y {\displaystyle f:(X,\tau )\to Y} is continuous (respectively, a quotient map) if and only if the same is true of f: ( X , τ f ) → Y . {\displaystyle f:\left(X,\tau _{f}\right)\to Y.}
Jefimenko's equations Heaviside–Feynman formula Jefimenko's_equations > Heaviside–Feynman formula The formula provides a natural generalization of the Coulomb's law for cases where the source charge is moving: E = − q 4 π ε 0 {\displaystyle \mathbf {E} ={\frac {-q}{4\pi \varepsilon _{0}}}\left} Here, E {\displaystyle \mathbf {E} } and B {\displaystyle \mathbf {B} } are the electric and magnetic fields respectively, q {\displaystyle q} is the electric charge, ε 0 {\displaystyle \varepsilon _{0}} is the vacuum permittivity (electric field constant) and c {\displaystyle c} is the speed of light. The vector e r ′ {\displaystyle \mathbf {e} _{r'}} is a unit vector pointing from the observer to the charge and r ′ {\displaystyle r'} is the distance between observer and charge. Since the electromagnetic field propagates at the speed of light, both these quantities are evaluated at the retarded time t − r ′ / c {\displaystyle t-r'/c} .
Implant induction welding of thermoplastics Equipment Implant_induction_welding_of_thermoplastics > Welding Process > Equipment An induction generator is used to produce high frequency current in the range of 2-10 Mhz. The range used is regulated by the FCC to avoid interference with broadcast signals. An induction coil converts the high frequency current from the induction generator into the necessary alternating magnetic field.
Small nucleolar RNA SNORD103 Summary Small_nucleolar_RNA_SNORD103 In molecular biology, snoRNA U103 (also known as SNORD103) is a non-coding RNA (ncRNA) molecule which functions in the modification of other small nuclear RNAs (snRNAs). This type of modifying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
Negative resistance Operation Negative_resistance > Operation One way in which the different types of resistance can be distinguished is in the directions of current and electric power between a circuit and an electronic component. The illustrations below, with a rectangle representing the component attached to a circuit, summarize how the different types work:
Fundamental thermodynamic relation Relationship to statistical mechanics Fundamental_thermodynamic_relation > Relationship to statistical mechanics The fundamental thermodynamic relation and statistical mechanical principles can be derived from one another.
Water-gas shift reaction Thermodynamics Water–gas_shift_reaction > Mechanism > Thermodynamics The WGSR is exergonic, with the following thermodynamic parameters at room temperature (298 K): In aqueous solution, the reaction is less exergonic.
Selective glucocorticoid receptor agonists Potential applications Selective_glucocorticoid_receptor_modulator > Potential applications In chronic inflammatory diseases like atopic dermatitis (skin), rheumatoid arthritis (joints),..., the side effects of corticosteroids are problematic because of the necessary long-term treatment. Therefore, SEGRAMs are being investigated as an alternative topical treatment. Systemic long-term treatment of inflammations with corticosteroids is particularly liable to cause metabolic side-effects, which makes the development of oral SEGRAMs an interesting goal. It remains to be seen whether selective receptor agonists or modulators indeed cause significantly less side-effects than classical corticoids in clinical applications.
Type 1 innate lymphoid cell Tumor microenvironment LTi_cells > Function > Tumor microenvironment If successful, the recruitment of these cells will kill the tumorigenic cells, however in some cases, IFN-γ and TNF-α can play a role in the induction of immunosuppressive immune cells, such as MDSCs, and therefore anti-inflammatory cytokines, allowing an immune environment the tumor cells can escape from.The role of ILC2s and ILC3s in tumor surveillance is dependent on the microenvironment encountered in their resident tissues. ILC2s produce cytokines that promote an anti-inflammatory immune response e.g. IL-13, IL-4, Amphiregulin, favouring tumor growth.
RNA Tie Club Background RNA_Tie_Club > History > Background In 1953, English biophysicist Francis Crick and American biologist James Watson, working together at the Cavendish Laboratory of the University of Cambridge, described correctly of the structure of DNA, the principal genetic materials in organisms, and based on it developed the concept of genetic information between DNA and proteins. By 1954, it was becoming to be understood that genetic information pathway involved DNA, RNA and proteins. However, the structure and nature of RNA were still a mystery (specific RNA molecules were not known until 1960), especially on how RNAs are involved in protein synthesis.
New Breeding Techniques Methods involved New_Breeding_Techniques > Methods involved New breeding techniques (NBTs) make specific changes within plant DNA in order to change its traits, and these modifications can vary in scale from altering single base, to inserting or removing one or more genes. The various methods of achieving these changes in traits include the following: Cutting and modifying the genome during the repair process (three tools are used to achieve this: Zinc finger nuclease; TALENs, and CRISPR/Cas Tools) Genome editing to introduce changes to just a few base pairs (using a technique called 'oligonucleotide-directed mutagenesis' (ODM)). Transferring a gene from an identical or closely related species (cisgenesis) Adding in a reshuffled set of regulatory instructions from same species (intragenesis) Deploying processes that alter gene activity without altering the DNA itself (epigenetic methods) Grafting of unaltered plant onto a genetically modified rootstock
Colon cancer Histopathology Colorectal_cancer > Diagnosis > Histopathology The histopathologic characteristics of the tumor are reported from the analysis of tissue taken from a biopsy or surgery. A pathology report contains a description of the microscopical characteristics of the tumor tissue, including both tumor cells and how the tumor invades into healthy tissues and finally if the tumor appears to be completely removed. The most common form of colon cancer is adenocarcinoma, constituting between 95% and 98% of all cases of colorectal cancer.
Apache Wave Summary Google_Wave Google Wave, later known as Apache Wave, was a software framework for real-time collaborative editing online. Originally developed by Google and announced on May 28, 2009, it was renamed to Apache Wave when the project was adopted by the Apache Software Foundation as an incubator project in 2010. Wave is a web-based computing platform and communications protocol designed to merge key features of communications media, such as email, instant messaging, wikis, and social networking. Communications using the system can be synchronous or asynchronous.
Quantum algorithms Hybrid quantum/classical algorithms Quantum_algorithm > Hybrid quantum/classical algorithms Hybrid Quantum/Classical Algorithms combine quantum state preparation and measurement with classical optimization. These algorithms generally aim to determine the ground state eigenvector and eigenvalue of a Hermitian Operator.
Transitive reduction Computing the reduction in sparse graphs Transitive_reduction > Computational complexity > Computing the reduction in sparse graphs When measured both in terms of the number n of vertices and the number m of edges in a directed acyclic graph, transitive reductions can also be found in time O(nm), a bound that may be faster than the matrix multiplication methods for sparse graphs. To do so, apply a linear time longest path algorithm in the given directed acyclic graph, for each possible choice of starting vertex. From the computed longest paths, keep only those of length one (single edge); in other words, keep those edges (u,v) for which there exists no other path from u to v. This O(nm) time bound matches the complexity of constructing transitive closures by using depth-first search or breadth first search to find the vertices reachable from every choice of starting vertex, so again with these assumptions transitive closures and transitive reductions can be found in the same amount of time.
Ribosome shunting Ribosome shunt in Adenovirus Ribosome_shunting > Ribosome shunt in Adenovirus The mechanism for ribosome shunt involves the larger subunit binding upstream of the start codon. The polymerase is then able to leapfrog using protein binding and a power stroke to bypass the start codon on the coding mRNA. The tripate is then inserted into the parent strand to create a new binding site for further replication. == References ==
Direct function Dfns versus tradfns Direct_function > Dfns versus tradfns A dfn is handier than a tradfn as an operand (see preceding items: a tradfn must be named; a tradfn is named by embedding ...). Names assigned in a dfn are local by default; names assigned in a tradfn are global unless specified in a locals list.
Information based complexity Brief history Information-based_complexity > Brief history This research was published in the 1964 monograph Iterative Methods for the Solution of Equations. The general setting for information-based complexity was formulated by Traub and Woźniakowski in 1980 in A General Theory of Optimal Algorithms. For a list of more recent monographs and pointers to the extensive literature see To Learn More below.
Linear predictor function Linear regression Linear_predictor_function > Linear regression An example of the usage of a linear predictor function is in linear regression, where each data point is associated with a continuous outcome yi, and the relationship written y i = f ( i ) + ε i = β T x i + ε i , {\displaystyle y_{i}=f(i)+\varepsilon _{i}={\boldsymbol {\beta }}^{\mathrm {T} }\mathbf {x} _{i}\ +\varepsilon _{i},} where ε i {\displaystyle \varepsilon _{i}} is a disturbance term or error variable — an unobserved random variable that adds noise to the linear relationship between the dependent variable and predictor function.
Spectroradiometer Incorrect settings Spectroradiometer > Definitions > Incorrect settings Other things being equal, the Signal-to-Noise Ratio (SNR) of the collected spectra improves by the square root of the number N of scans averaged. For example, if 16 spectral scans are averaged, the SNR is improved by a factor of 4 over that of a single scan. S/N ratio is measured at the input light level which reaches the full scale of the spectrometer.
Amphetamine-type stimulant Psychosis Amphetamine_type_stimulant > Adverse effects > Psychosis Though some believed that the ATS-induced psychosis cannot be distinguished from schizophrenia, delusions of persecution are often reported as a characteristic of ATS-induced psychosis.The duration of ATS-induced psychosis has substantial variations, from weeks to months. Based on their durations, psychosis can be divided into two types. One type has a shorter psychotic state that shows improvement as the central action of ATS changes. The other type has a longer duration.
Info-gap decision theory Generic models Info-gap_decision_theory > Classical decision theory perspective > Maximin/Minimin: playing robustness/opportuneness games with Nature > Generic models The basic conceptual framework that classical decision theory provides for dealing with uncertainty is that of a two-player game. The two players are the decision maker (DM) and Nature, where Nature represents uncertainty. More specifically, Nature represents the DM's attitude towards uncertainty and risk. Note that a clear distinction is made in this regard between a pessimistic decision maker and an optimistic decision maker, namely between a worst-case attitude and a best-case attitude.
Rock microstructure Spherulites Rock_microstructure > Igneous microstructure > Spherulites Spherulitic texture is the result of cooling and nucleation of material in a magma which has achieved supersaturation in the crystal component. Thus it is often a subsolidus process in supercooler felsic rocks. Often, two minerals will grow together in the spherulite. Axiolitic texture results from spherulitic growth along fractures in volcanic glass, often from invasion of water.
Thought collective Genesis and Development of a Scientific Fact Thought_collective > Genesis and Development of a Scientific Fact These common concepts and practices both provide a shared language of science within which they can communicate, and consequently limit the possibilities of thought that the researchers can have. Under the influence of a particular "thought style," the common concepts and practices previously mentioned, a community of researchers "shares joint attributes of problems and judgments considered as evident, joint methods to acquire knowledge, and agrees in the determination of meaningless questions." Within this conception of the production of scientific knowledge, the ideas, concepts, and theories of these researchers are permanently conditioned by their present "thought style" and cannot be considered independently of them.
Global concurrency control Serializability Concurrency_control > Concurrency control in databases > Major goals of concurrency control mechanisms > Correctness > Serializability Serializability is considered the highest level of isolation among database transactions, and the major correctness criterion for concurrent transactions. In some cases compromised, relaxed forms of serializability are allowed for better performance (e.g., the popular Snapshot isolation mechanism) or to meet availability requirements in highly distributed systems (see Eventual consistency), but only if application's correctness is not violated by the relaxation (e.g., no relaxation is allowed for money transactions, since by relaxation money can disappear, or appear from nowhere). Almost all implemented concurrency control mechanisms achieve serializability by providing Conflict serializablity, a broad special case of serializability (i.e., it covers, enables most serializable schedules, and does not impose significant additional delay-causing constraints) which can be implemented efficiently.
Gene expression profiling in cancer Summary Gene_expression_profiling_in_cancer Cancer is a category of disease characterized by uncontrolled cell growth and proliferation. For cancer to develop, genes regulating cell growth and differentiation must be altered; these mutations are then maintained through subsequent cell divisions and are thus present in all cancerous cells. Gene expression profiling is a technique used in molecular biology to query the expression of thousands of genes simultaneously. In the context of cancer, gene expression profiling has been used to more accurately classify tumors. The information derived from gene expression profiling often helps in predicting the patient's clinical outcome.
Data classification (data management) Summary Data_classification_(data_management) In the field of data management, data classification as a part of the Information Lifecycle Management (ILM) process can be defined as a tool for categorization of data to enable/help organizations to effectively answer the following questions: What data types are available? Where are certain data located? What access levels are implemented?
Piecewise-constant valuation Generalization Piecewise-uniform_valuation > Generalization A piecewise-linear valuation is a generalization of piecewise-constant valuation in which the value-density in each region j is a linear function, ajx+bj (piecewise-constant corresponds to the special case in which aj=0 for all j). == References ==
Launching gantry Operation and design Launching_gantry > Operation and design Each trolley is equipped with two winches: a main winch to suspend the load, and a translation winch to move the trolley along the girders. : 38–39 When bridge segments (or bridge girders) are delivered at the ground level, the launching gantry is used to pick them up and raise them to deck or pier height. If the segments (or girders) are delivered instead at the bridge deck level, the launching gantry moves back to allow the forward trolley to pick up the front end of the next segment (or girder), while the back end of the segment (or girder) is supported by the transportation vehicle; as the forward trolley moves forward, the rear trolley takes over supporting the back end from the vehicle.
Comparison of reference management software General Comparison_of_reference_management_software > General In the "notes" section, there is a difference between: web-based, referring to applications that may be installed on a web server (usually requiring MySQL or another database and PHP, Perl, Python, or some other language for web applications) a centrally hosted website
Philosophic burden of proof In statistics Philosophic_burden_of_proof > Application > In statistics In inferential statistics, the null hypothesis is a general statement or default position that there is no relationship between two measured phenomena, or no association among groups. Rejecting or disproving the null hypothesis—and thus concluding that there are grounds for believing that there is a relationship between two phenomena (e.g. that a potential treatment has a measurable effect)—is a central task in the modern practice of science; the field of statistics gives precise criteria for rejecting a null hypothesis. The null hypothesis is generally assumed to be true until evidence indicates otherwise. In statistics, it is often denoted H0 (read "H-nought", "H-null", "H-oh", or "H-zero").
Charles Babbage "Babbage principle" Charles_Babbage > Academic > On the Economy of Machinery and Manufactures > "Babbage principle" The term was introduced in 1974 by Harry Braverman. Related formulations are the "principle of multiples" of Philip Sargant Florence, and the "balance of processes".What Babbage remarked is that skilled workers typically spend parts of their time performing tasks that are below their skill level. If the labour process can be divided among several workers, labour costs may be cut by assigning only high-skill tasks to high-cost workers, restricting other tasks to lower-paid workers. He also pointed out that training or apprenticeship can be taken as fixed costs; but that returns to scale are available by his approach of standardisation of tasks, therefore again favouring the factory system. His view of human capital was restricted to minimising the time period for recovery of training costs.
Quantum theory of information Quantum information processing Quantum_information_theory > Quantum information processing Quantum information can be moved about, in a quantum channel, analogous to the concept of a classical communications channel. Quantum messages have a finite size, measured in qubits; quantum channels have a finite channel capacity, measured in qubits per second. Quantum information, and changes in quantum information, can be quantitatively measured by using an analogue of Shannon entropy, called the von Neumann entropy.
Strauss–Howe generational theory Timing of generations and turnings Strauss–Howe_generational_theory > Timing of generations and turnings According to Strauss and Howe, however, this is not the case. As long as the transition to adulthood occurs around age 20, the transition to midlife around age 40, and the transition to old age around age 60, they say the basic length of both generations and turnings will remain the same.In their book, The Fourth Turning, however, Strauss and Howe say that the precise boundaries of generations and turnings are erratic. The generational rhythm is not like certain simple, inorganic cycles in physics or astronomy, where time and periodicity can be predicted to the second.
Phenotypic integration Evolution of Phenotypic Integration Phenotypic_integration > Evolution of Phenotypic Integration Even if selection favors the correlations, it will not be maintained unless those conditions are met. Selection will favor tight linkage because it is maintained better. Poorly linked genetic correlations will not last.
Complex Network Summary Complex_Network In the context of network theory, a complex network is a graph (network) with non-trivial topological features—features that do not occur in simple networks such as lattices or random graphs but often occur in networks representing real systems. The study of complex networks is a young and active area of scientific research (since 2000) inspired largely by empirical findings of real-world networks such as computer networks, biological networks, technological networks, brain networks, climate networks and social networks.
John Derbyshire Mathematics John_Derbyshire > Career > Mathematics Derbyshire's book Prime Obsession: Bernhard Riemann and the Greatest Unsolved Problem in Mathematics was first published in hardcover in 2003 and then paperback in 2004. It focuses on the Riemann hypothesis, one of the Millennium Problems. The book is aimed, as Derbyshire puts it in his prologue, "at the intelligent and curious but nonmathematical reader ..." Prime Obsession explores such topics as complex numbers, field theory, the prime number theorem, the zeta function, the harmonic series, and others. The biographical sections give relevant information about the lives of mathematicians who worked in these areas, including Euler, Gauss, Lejeune Dirichlet, Lobachevsky, Chebyshev, Vallée-Poussin, Hadamard, as well as Riemann himself.In 2006, Joseph Henry Press published another Derbyshire book of popular mathematics: Unknown Quantity: A Real And Imaginary History of Algebra.
Industrial scale General and cited references Economies_of_scale > References > General and cited references Repr. in Kurz, H.D. ; Salvadori, N.
Glossary of experimental design Glossary Glossary_of_experimental_design > Glossary Alias: When the estimate of an effect also includes the influence of one or more other effects (usually high order interactions) the effects are said to be aliased (see confounding). For example, if the estimate of effect D in a four factor experiment actually estimates (D + ABC), then the main effect D is aliased with the 3-way interaction ABC. Note: This causes no difficulty when the higher order interaction is either non-existent or insignificant. Analysis of variance (ANOVA): A mathematical process for separating the variability of a group of observations into assignable causes and setting up various significance tests.
Spatiotemporal Epidemiological Modeler Summary Spatiotemporal_Epidemiological_Modeler The nodes in the graph correspond to places or regions, and the edges in the graph describe relationships or connections between regions. Both the nodes and the edges can be labeled or "decorated" with a variety of denominator data and models. This graphical representation is implemented using the Eclipse Modeling Framework (EMF).
Endothelial Cell Tropism Coronaviruses Cell_tropism > Examples and effects on viral pathogenesis > Coronaviruses SARS-CoV-2 is the virus that causes the disease COVID-19 and infects different cell types, but also has shown multi-organ vascular involvement. In severe cases, SARS-CoV-2 can cause endothelial dysfunction or injury. This virus-induced endothelial responses can lead to thrombosis, congestion, and microangiopathy. The cell surface receptors associated with viral entry include ACE2 and co-receptor TMPRSS2. TMPRSS2 is needed to cleave the spike protein for viral fusion to cell membrane. However, a recent study has demonstrated that low expression of ACE2 in endothelial cells has been associated with poor ability for viral propagation due the lack of the entry points on the cell surface.
Matrix element (physics) Summary Matrix_element_(physics) In physics, particularly in quantum perturbation theory, the matrix element refers to the linear operator of a modified Hamiltonian using Dirac notation. The matrix element considers the effect of the newly modified Hamiltonian (i.e. the linear superposition of the unperturbed Hamiltonian plus interaction potential) on the quantum state. Matrix elements are important in atomic, nuclear and particle physics.
3 Mathematics 3 > Mathematics 3 is the number of non-collinear points needed to determine a plane, a circle, and a parabola. Three is the only prime which is one less than a perfect square. Any other number which is n 2 {\displaystyle n^{2}} − 1 for some integer n {\displaystyle n} is not prime, since it is ( n {\displaystyle n} − 1)( n {\displaystyle n} + 1).
Point mutation Causes Nucleotide_substitution > Causes Point mutations usually take place during DNA replication. DNA replication occurs when one double-stranded DNA molecule creates two single strands of DNA, each of which is a template for the creation of the complementary strand. A single point mutation can change the whole DNA sequence. Changing one purine or pyrimidine may change the amino acid that the nucleotides code for.
Chain Rule Further generalizations Chain_Rule > Further generalizations It associates to each space a new space and to each function between two spaces a new function between the corresponding new spaces. In each of the above cases, the functor sends each space to its tangent bundle and it sends each function to its derivative. For example, in the manifold case, the derivative sends a Cr-manifold to a Cr−1-manifold (its tangent bundle) and a Cr-function to its total derivative.
Gene regulatory network Summary Genetic_pathway Thus a yeast cell, finding itself in a sugar solution, will turn on genes to make enzymes that process the sugar to alcohol. This process, which we associate with wine-making, is how the yeast cell makes its living, gaining energy to multiply, which under normal circumstances would enhance its survival prospects. In multicellular animals the same principle has been put in the service of gene cascades that control body-shape.
Temperature-responsive polymers Thermoreversible materials Temperature-responsive_polymer > Applications > Thermoresponsive gels > Thermoreversible materials Some thermoreversible gels are used in biomedicine. For instance, hydrogels made of proteins are used as scaffolds in knee replacement. In baking, thermoreversible glazes such as pectin are prized for their ability to set and then reset after melting, and are used in nappage and other processes to ensure a smooth final surface for a presented dish. In manufacturing, thermoplastic elastomers can be set into a shape and then reset to their original shape through thermal reversibility, unlike one-way thermoset elastomers.
Hyperbolic PDE Summary Hyperbolic_PDE In mathematics, a hyperbolic partial differential equation of order n {\displaystyle n} is a partial differential equation (PDE) that, roughly speaking, has a well-posed initial value problem for the first n − 1 {\displaystyle n-1} derivatives. More precisely, the Cauchy problem can be locally solved for arbitrary initial data along any non-characteristic hypersurface. Many of the equations of mechanics are hyperbolic, and so the study of hyperbolic equations is of substantial contemporary interest. The model hyperbolic equation is the wave equation.
Amylose Function Amylose > Function Hence, a common test is the iodine test for starch. Mix starch with a small amount of yellow iodine solution. In the presence of amylose, a blue-black color will be observed.
Optical decay Deformed vacuum Optical_decay > Deformed vacuum The decay rate can be affected by the distortion of uniform density of states of photons, due, for example, an external cavity or a nanofiber located in vicinity of the atom or by simply placing the system near a dielectric or metallic boundary. == References ==
Non-linear dynamics Ergodic systems Non-linear_dynamical_system > Ergodic systems In many dynamical systems, it is possible to choose the coordinates of the system so that the volume (really a ν-dimensional volume) in phase space is invariant. This happens for mechanical systems derived from Newton's laws as long as the coordinates are the position and the momentum and the volume is measured in units of (position) × (momentum). The flow takes points of a subset A into the points Φ t(A) and invariance of the phase space means that v o l ( A ) = v o l ( Φ t ( A ) ) . {\displaystyle \mathrm {vol} (A)=\mathrm {vol} (\Phi ^{t}(A)).}
Electron-on-Helium Qubit History of electrons on helium Electron-on-Helium_Qubit > History of electrons on helium As a result, the electron remains trapped outside the liquid. The energy of the electron in this potential well is quantised in a Hydrogen-like series with the modified Rydberg constant RHe ≈ {\displaystyle \approx } 10−4 RH. The binding energies of the ground (n = 1) and first excited (n = 2) states are -7.6 K and -1.9 K respectively and, as the energy required for excitation is higher than the typical experimental temperature ( ≲ {\displaystyle \lesssim } 1 K), the electron remains in the ground state, trapped several nanometres above the liquid surface.
Indium Chemical Indium > Properties > Chemical Indium has 49 electrons, with an electronic configuration of 4d105s25p1. In compounds, indium most commonly donates the three outermost electrons to become indium(III), In3+. In some cases, the pair of 5s-electrons are not donated, resulting in indium(I), In+. The stabilization of the monovalent state is attributed to the inert pair effect, in which relativistic effects stabilize the 5s-orbital, observed in heavier elements.
Eigenvalue, eigenvector, and eigenspace Eigenspaces, geometric multiplicity, and the eigenbasis for matrices Spectral_properties > Eigenvalues and eigenvectors of matrices > Eigenspaces, geometric multiplicity, and the eigenbasis for matrices As long as u + v and αv are not zero, they are also eigenvectors of A associated with λ. The dimension of the eigenspace E associated with λ, or equivalently the maximum number of linearly independent eigenvectors associated with λ, is referred to as the eigenvalue's geometric multiplicity γ A ( λ ) {\displaystyle \gamma _{A}(\lambda )} . Because E is also the nullspace of (A − λI), the geometric multiplicity of λ is the dimension of the nullspace of (A − λI), also called the nullity of (A − λI), which relates to the dimension and rank of (A − λI) as Because of the definition of eigenvalues and eigenvectors, an eigenvalue's geometric multiplicity must be at least one, that is, each eigenvalue has at least one associated eigenvector. Furthermore, an eigenvalue's geometric multiplicity cannot exceed its algebraic multiplicity.
Cardiac tamponade Differential diagnosis Pericardial_tamponade > Diagnosis > Differential diagnosis Initial diagnosis of cardiac tamponade can be challenging, as there is a broad differential diagnosis. The differential includes possible diagnoses based on symptoms, time course, mechanism of injury, patient history. Rapid onset cardiac tamponade may also appear similar to pleural effusions, shock, pulmonary embolism, and tension pneumothorax.If symptoms appeared more gradually, the differential diagnosis includes acute heart failure.In a person with trauma presenting with pulseless electrical activity in the absence of hypovolemia and tension pneumothorax, the most likely diagnosis is cardiac tamponade.In addition to the diagnostic complications afforded by the wide-ranging differential diagnosis for chest pain, diagnosis can be additionally complicated by the fact that people will often be weak or faint at presentation. For instance, a fast rate of breathing and difficulty breathing on exertion that progresses to air hunger at rest can be a key diagnostic symptom, but it may not be possible to obtain such information from people who are unconscious or who have convulsions at presentation.
Pose tracking Magnetic tracking Pose_tracking > Magnetic tracking Magnetic tracking (or electromagnetic tracking) is based on the same principle as a theremin. It relies on measuring the intensity of inhomogenous magnetic fields with electromagnetic sensors. A base station, often referred to as the system's transmitter or field generator, generates an alternating or a static electromagnetic field, depending on the system's architecture. To cover all directions in the three dimensional space, three magnetic fields are generated sequentially.
ARTAS Unit groups ARTAS > Unit groups Four groups of main functions are implemented in an ARTAS Unit: The TRACKER processes the sensor input data to maintain a real-time air situation, represented in a Track Data Base. The SERVER performs the Track and Sensor Information Services i.e. the management of all requests from Users and the transmission of the relevant sets of track/sensor data to these Users, and the so-called inter-ARTAS co-operation functions The ROUTER BRIDGE manages the external interfaces to the Normal Users, the Broadcast Users, the Adjacent ARTAS Units and the surveillance sensors. It also implements the Surveillance Sensor Input Processing function. The SYSTEM MANAGER processes the functions related to the Human supervision and management of the ARTAS Unit.
Oblique illumination Sub-diffraction techniques Laser_microscopy > Optical microscopy > Sub-diffraction techniques A multitude of super-resolution microscopy techniques have been developed in recent times which circumvent the diffraction limit. This is mostly achieved by imaging a sufficiently static sample multiple times and either modifying the excitation light or observing stochastic changes in the image. The deconvolution methods described in the previous section, which removes the PSF induced blur and assigns a mathematically 'correct' origin of light, are used, albeit with slightly different understanding of what the value of a pixel mean. Assuming most of the time, one single fluorophore contributes to one single blob on one single taken image, the blobs in the images can be replaced with their calculated position, vastly improving resolution to well below the diffraction limit. To realize such assumption, Knowledge of and chemical control over fluorophore photophysics is at the core of these techniques, by which resolutions of ~20 nanometers are obtained.
Distal renal tubular acidosis Diagnosis Distal_renal_tubular_acidosis > Diagnosis The pH of patient's blood is highly variable, and acidemia is not necessarily characteristic of people with dRTA at any given time. One may have dRTA caused by alpha intercalated cell failure without necessarily being acidemic; termed incomplete dRTA, which is characterized by an inability to acidify urine, without affecting blood pH or plasma bicarbonate levels. The diagnosis of dRTA can be made by the observation of a relatively alkaline urinary pH of greater than 5.3 in the face of a systemic acidemia (usually taken to be a serum bicarbonate of 20 mmol/L or less).
Pancreatic cancer Surgery Pancreatic_cancer > Management > Exocrine cancer > Surgery Surgery with the intention of a cure is only possible in around one-fifth (20%) of new cases. Although CT scans help, in practice it can be difficult to determine whether the tumor can be fully removed (its "resectability"), and it may only become apparent during surgery that it is not possible to successfully remove the tumor without damaging other vital tissues. Whether or not surgical resection can be offered depends on various factors, including the precise extent of local anatomical adjacency to, or involvement of, the venous or arterial blood vessels, as well as surgical expertise and a careful consideration of projected post-operative recovery. The age of the person is not in itself a reason not to operate, but their general performance status needs to be adequate for a major operation.One particular feature that is evaluated is the encouraging presence, or discouraging absence, of a clear layer or plane of fat creating a barrier between the tumor and the vessels.
Binding pocket Approximation of the reactant Catalytic_site > Mechanisms involved in Catalytic process > Approximation of the reactant In the end, the active site may manipulate the Molecular orbital of the substrate into a suitable orientation to reduce activation energy. : 155–8 The electrostatic states of substrate and active site must be complementary to each other. A polarized negatively charged amino acid side chain will repel uncharged substrate. But if the transition state involves the formation of an ion centre then the side chain will now produce a favourable interaction.
Launching gantry Operation and design Launching_gantry > Operation and design When launching, the forward end of the machine is supported (on sliding rails) by a strut lowered onto a bridge support column, while the truck for that end hangs off the gantry backbone with no support from beneath. Once the gantry straddles the open span, the bridge segment is lowered onto the bridge support piers, and the process reverses to retract the launching gantry. The SLJ900 moves at 8 km/h (5 mph) unloaded, and 5 km/h (3 mph) carrying a bridge segment. Launching gantries are often distinguished by the design of the main girders.
Natural refrigerant Noble gases as refrigerants Natural_refrigerant > Refrigerants > Noble gases as refrigerants The noble gases are rarely used as refrigerants. The primary uses of noble gases as refrigerants is in liquid super coolant experimental systems in laboratories or in superconductors. This specifically applies to liquid helium, which has a boiling point of 4.2 K. They are never used for industrial or home refrigeration.
Completely randomized design Example Completely_randomized_design > Example A typical example of a completely randomized design is the following: k = 1 factor (X1) L = 4 levels of that single factor (called "1", "2", "3", and "4") n = 3 replications per level N = 4 levels × 3 replications per level = 12 runs
Man-Computer Symbiosis Parts of the work Man-Computer_Symbiosis > Parts of the work The work shows the following contents:
Language identification in the limit Finite elasticity Language_identification_in_the_limit > Sufficient conditions for learnability > Finite elasticity . . , s n − 1 } {\displaystyle \{s_{1},...,s_{n-1}\}} .It is shown that a class of recursively enumerable languages is learnable in the limit if it has finite elasticity.
List of textbooks on classical mechanics and quantum mechanics Classical mechanics List_of_textbooks_on_classical_mechanics_and_quantum_mechanics > Advanced undergraduate and graduate > Classical mechanics ISBN 0-7506-2896-0. Marsden, J. E.; Ratiu, T. S. (1999).
Mechanical vibration Resonance causes Mechanical_vibration > Analysis > Forced vibration with damping > Resonance causes Applying a force to the mass and spring is similar to pushing a child on swing, a push is needed at the correct moment to make the swing get higher and higher. As in the case of the swing, the force applied need not be high to get large motions, but must just add energy to the system. The damper, instead of storing energy, dissipates energy.
Cache memory Buffer vs. cache Write_through_cache > Buffer vs. cache The semantics of a "buffer" and a "cache" are not totally different; even so, there are fundamental differences in intent between the process of caching and the process of buffering. Fundamentally, caching realizes a performance increase for transfers of data that is being repeatedly transferred. While a caching system may realize a performance increase upon the initial (typically write) transfer of a data item, this performance increase is due to buffering occurring within the caching system. With read caches, a data item must have been fetched from its residing location at least once in order for subsequent reads of the data item to realize a performance increase by virtue of being able to be fetched from the cache's (faster) intermediate storage rather than the data's residing location.
Dental antibiotic prophylaxis Summary Dental_antibiotic_prophylaxis Dental antibiotic prophylaxis is the administration of antibiotics to a dental patient for prevention of harmful consequences of bacteremia, that may be caused by invasion of the oral flora into an injured gingival or peri-apical vessel during dental treatment. This issue remains a subject under constant revision, with the intention of providing recommendations based on sound scientific evidence. In the past, bacteremia caused by dental procedures (in most cases due to viridans streptococci, which reside in oral cavity), such as a cleaning or extraction of a tooth was thought to be more clinically significant than it actually was.
Thermodynamic laws Summary Thermodynamic_laws A common corollary of the statement is that heat does not spontaneously pass from a colder body to a warmer body. The third law of thermodynamics states that a system's entropy approaches a constant value as the temperature approaches absolute zero. With the exception of non-crystalline solids (glasses), the entropy of a system at absolute zero is typically close to zero.The first and second laws prohibit two kinds of perpetual motion machines, respectively: the perpetual motion machine of the first kind which produces work with no energy input, and the perpetual motion machine of the second kind which spontaneously converts thermal energy into mechanical work.
Binary search Performance Binary_search_algorithm > Performance The comparison tree representing binary search has the fewest levels possible as every level above the lowest level of the tree is filled completely. Otherwise, the search algorithm can eliminate few elements in an iteration, increasing the number of iterations required in the average and worst case. This is the case for other search algorithms based on comparisons, as while they may work faster on some target values, the average performance over all elements is worse than binary search. By dividing the array in half, binary search ensures that the size of both subarrays are as similar as possible.
Airport security Process and equipment Airport_security > Process and equipment These detect volatile compounds given off from explosives using gas chromatography.Computed tomography and walk-through body scanning (Thz radiation) may also be done. Artificial intelligence systems are also being used, for example for translation service on information stations around the airport and for reducing the time airplanes spend at the gate between flights (by monitoring and analyzing everything that happens after the aircraft lands). In the future, it may also be used in conjunction with CT machines and Thz radiation detectors.
Structure of DNA Base pairing Sense_and_antisense > Properties > Base pairing The two strands of DNA in a double helix can thus be pulled apart like a zipper, either by a mechanical force or high temperature. As a result of this base pair complementarity, all the information in the double-stranded sequence of a DNA helix is duplicated on each strand, which is vital in DNA replication. This reversible and specific interaction between complementary base pairs is critical for all the functions of DNA in organisms.
Partial fraction Summary Partial_fractions_in_integration In algebra, the partial fraction decomposition or partial fraction expansion of a rational fraction (that is, a fraction such that the numerator and the denominator are both polynomials) is an operation that consists of expressing the fraction as a sum of a polynomial (possibly zero) and one or several fractions with a simpler denominator.The importance of the partial fraction decomposition lies in the fact that it provides algorithms for various computations with rational functions, including the explicit computation of antiderivatives, Taylor series expansions, inverse Z-transforms, and inverse Laplace transforms. The concept was discovered independently in 1702 by both Johann Bernoulli and Gottfried Leibniz.In symbols, the partial fraction decomposition of a rational fraction of the form f ( x ) g ( x ) , {\textstyle {\frac {f(x)}{g(x)}},} where f and g are polynomials, is its expression as where p(x) is a polynomial, and, for each j, the denominator gj (x) is a power of an irreducible polynomial (that is not factorable into polynomials of positive degrees), and the numerator fj (x) is a polynomial of a smaller degree than the degree of this irreducible polynomial. When explicit computation is involved, a coarser decomposition is often preferred, which consists of replacing "irreducible polynomial" by "square-free polynomial" in the description of the outcome. This allows replacing polynomial factorization by the much easier-to-compute square-free factorization. This is sufficient for most applications, and avoids introducing irrational coefficients when the coefficients of the input polynomials are integers or rational numbers.
Tennessine Atomic and physical Tennessine > Predicted properties > Atomic and physical In tennessine atoms, this lowers the 7s and the 7p electron energy levels, stabilizing the corresponding electrons, although two of the 7p electron energy levels are more stabilized than the other four. The stabilization of the 7s electrons is called the inert pair effect; the effect that separates the 7p subshell into the more-stabilized and the less-stabilized parts is called subshell splitting. Computational chemists understand the split as a change of the second (azimuthal) quantum number l from 1 to 1/2 and 3/2 for the more-stabilized and less-stabilized parts of the 7p subshell, respectively.
TORQUE Feature set TORQUE > Feature set TORQUE provides enhancements over standard OpenPBS in the following areas: Fault Tolerance Additional failure conditions checked/handled Node health check script support Scheduling Interface Extended query interface providing the scheduler with additional and more accurate information Extended control interface allowing the scheduler increased control over job behavior and attributes Allows the collection of statistics for completed jobs Scalability Significantly improved server to worker nodes' Machine Oriented Mini-server (MOM) communication model Ability to handle larger clusters (over 15 TF/2,500 processors) Ability to handle larger jobs (over 2000 processors) Ability to support larger server messages Usability Extensive logging additions More human readable logging (i.e. no more "error 15038 on command 42")

Subsets and Splits

No community queries yet

The top public SQL queries from the community will appear here once available.