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This is a list of notable computer-aided engineering software . | https://en.wikipedia.org/wiki/List_of_computer-aided_engineering_software |
This is a list of computer-aided manufacturing (CAM) software. | https://en.wikipedia.org/wiki/List_of_computer-aided_manufacturing_software |
A computer-animated film is an animated film that was created using computer software to appear three-dimensional . While traditional 2D animated films are now [ when? ] made primarily with the help of computers, the technique to render realistic 3D computer graphics (CG) or 3D computer-generated imagery (CGI), is unique to computer animation.
This is a list of theatrically released feature films that are entirely computer-animated.
Release date listed is the first public theatrical screening of the completed film. This may mean that the dates listed here may not be representative of when the film came out in a particular country.
The country or countries listed reflects the places where the production companies for each title are based. This means that the countries listed for a film might not reflect the location where the film was produced or the countries where the film received a theatrical release . If a title is a multi-country production, the country listed first corresponds with the production company that had the most significant role in the film's creation. | https://en.wikipedia.org/wiki/List_of_computer-animated_films |
This is a list of released animated television series made mainly with computer animation . | https://en.wikipedia.org/wiki/List_of_computer-animated_television_series |
Computer-assisted organic synthesis software is a type of application software used in organic chemistry in tandem with computational chemistry to help facilitate the tasks of designing, predicting, and producing chemical reactions . CAOS aims to identify a series of chemical reactions which, from a starting compound, can produce a desired molecule . CAOS algorithms typically use two databases : a first one of known chemical reactions and a second one of known starting materials (i.e., typically molecules available commercially). Desirable synthetic plans cost less, have high yield, and avoid using hazardous reactions and intermediates. Typically cast as a planning problem, significant progress has been made in CAOS. | https://en.wikipedia.org/wiki/List_of_computer-assisted_organic_synthesis_software |
List of computer-related books which have articles on Wikipedia for themselves or their writers. | https://en.wikipedia.org/wiki/List_of_computer_books |
This is a list of computer graphics and descriptive geometry topics , by article name. | https://en.wikipedia.org/wiki/List_of_computer_graphics_and_descriptive_geometry_topics |
This is a list of computer hardware manufacturers in the Soviet Union :
Major Soviet hardware manufacturers and ministry affiliations in 1988: [ 1 ] | https://en.wikipedia.org/wiki/List_of_computer_hardware_manufacturers_in_the_Soviet_Union |
Below is a list of computer museums around the world, organized by continent and country, then alphabetically by location.
See also: Computer Conservation Society [ 64 ] | https://en.wikipedia.org/wiki/List_of_computer_museums |
The following is a list of notable computer simulation software . | https://en.wikipedia.org/wiki/List_of_computer_simulation_software |
This list of computer size categories attempts to list commonly used categories of computer by the physical size of the device and its chassis or case, in descending order of size. One generation's " supercomputer " is the next generation's " mainframe ", and a " PDA " does not have the same set of functions as a " laptop ", but the list still has value, as it provides a ranked categorization of devices. It also ranks some more obscure computer sizes. There are different sizes like minicomputers , microcomputers , mainframe computers and super computers. [ 1 ] [ 2 ]
These are mainly used for scientific calculations or simulations and processing big data with high precission. [ 2 ]
This is a very broad categorization that includes computers with a single microprocessor as their central processing unit (CPU). [ 2 ] [ 6 ] | https://en.wikipedia.org/wiki/List_of_computer_size_categories |
Computer hardware and software standards are technical standards instituted for compatibility and interoperability between software, systems, platforms and devices.
yyyy-mm-dd | https://en.wikipedia.org/wiki/List_of_computer_standards |
This article lists software and hardware that emulates computing platforms.
The host in this article is the system running the emulator, and the guest is the system being emulated.
The list is organized by guest operating system (the system being emulated), grouped by word length . Each section contains a list of emulators capable of emulating the specified guest, details of the range of guest systems able to be emulated, and the required host environment and licensing.
Any x86-64 host computer, Virtual Machine equivalent or Cloud.
While the ARM processor in the Acorn Archimedes is a 32-bit chip, it only had 26-bit addressing making an ARM/Archimedes emulator, such as Aemulor or others below, necessary for 26-bit compatibility, for later ARM processors have mostly dropped it.
Macintosh Plus , Macintosh II , Macintosh Quadra
Polish minicomputer Mera 400. Also in development hardware emulator in FPGA. [ 14 ]
SpectraVideo SVI318/328 , ColecoVision , Sega SG-1000
For Sinclair ZX Spectrum and clones [ 16 ]
(based on Fuse)
Thomson MO5, MO5E, MO5NR, MO6, T9000, Olivetti Prodest PC128 | https://en.wikipedia.org/wiki/List_of_computer_system_emulators |
A computer system is a nominally complete computer that includes the hardware , operating system (main software ), and the means to use peripheral equipment needed and used for full or mostly full operation. Such systems may constitute personal computers (including desktop computers , portable computers , laptops , all-in-ones , and more), mainframe computers , minicomputers , servers , and workstations , among other classes of computing. The following is a list of notable manufacturers and sellers of computer systems, both present and past. There are currently 424 companies in this incomplete list. | https://en.wikipedia.org/wiki/List_of_computer_system_manufacturers |
This is a list of computer systems that were significantly or completely designed in the former Yugoslavia before the breakup of the country in 1990s. This list does not include imported foreign computers. Some of these were assembled as per original manufacturer's license. See history of computer hardware in Yugoslavia for more information. | https://en.wikipedia.org/wiki/List_of_computer_systems_from_Yugoslavia |
I-Worm.BadtransII, Badtrans.gen
possible ? Stop making money and fix your software!!"[sic]. Caused over US$300,000,000 in damages, mostly to American infrastructure. [ 5 ] | https://en.wikipedia.org/wiki/List_of_computer_worms |
This is a list of people who are important or notable in the field of computing , but who are not primarily computer scientists or programmers. | https://en.wikipedia.org/wiki/List_of_computing_people |
The following is a list of vascular plants , bryophytes and lichens which are constant species in one or more community of the British National Vegetation Classification system. | https://en.wikipedia.org/wiki/List_of_constant_species_in_the_British_National_Vegetation_Classification |
The list of construction methods covers the processes and techniques used in the construction process. The construction method is essential for civil engineers; utilizing it appropriately can help to achieve the desired results. The term building refers to the creation of physical structures such as buildings, bridges or railways. One of the four types of buildings is residential and building methods are easiest to study in these structures.
Construction involves the creation of physical structures such as buildings, bridges or railways.
Bricks are small rectangular blocks that can be used to form parts of buildings, typically walls. Before 7,000 BC, bricks were formed from hand-molded mud and dried by the sun. During the Industrial Revolution , mass-produced bricks became a common alternative to stone. Stone was typically more expensive, less predictable and more difficult to handle. Bricks remain in common use. They are small and easy to handle, strong in compression, durable and low maintenance. They can be formed into complex shapes, providing ample opportunity for the construction of aesthetic designs.
The four basic types of structure are residential, institutional and commercial, industrial, and infrastructure/heavy. [ 1 ]
Residential buildings go through five main stages, including foundations, formwork, scaffolding, concrete work and reinforcement.
Foundations provide support for structures, transferring their load to layers of soil or rock that have sufficient bearing capacity and suitable settlement characteristics to support them. There are four types of foundation depending on the bearing capacity. Civil engineers will often determine what type of foundation is suitable for the respective bearing capacity. [ 2 ]
The foundation construction method depends on considerations such as:
Shallow foundations are used where the loads forced by a structure are low relative to the bearing capacity of the surface soils. Deep foundations are needed where the bearing capacity of the surface soils is insufficient. Those loads need to be transferred to deeper layers with higher bearing capacity.
Raft foundations are slabs that cover a wide area, often the entire building footprint. They are suitable where ground conditions are too poor to create individual strip or pad foundations for a large number of individual loads. Raft foundations may combine beams to add support for specific loads.
Pile foundations are rectangular or circular pads used to support loads such as columns.
Strip foundations provide a continuous line of support to a linear structure such as a wall. Trench fill foundations are a variation of strip foundations. The trench excavation is almost completely filled with concrete. Rubble trench foundations are a further variation of trench fill foundations and are a traditional construction method that uses loose stone or rubble to minimise the use of concrete and improve drainage.
Formwork is used for the process of creating a mold into which concrete is poured and solidified. Traditional formwork is fabricated using wood, but it can employ steel, glass fibre, reinforced plastics and other materials. [ 3 ]
Formwork for beams takes the form of a box that is supported and propped in the correct position and level. The removal time for the formwork will vary with air temperature, humidity and consequent curing rate. Typical striking times are as follows (using air temperature of 7-16 °C):
This consists of a vertical mold of the desired shape and size matching the column to be poured. To keep the material thickness to a minimum, horizontal steel or timber clamps (or yokes) are used for batch filling and at varying centers for filling that is completed in one pour.
The head of the column can provide support for the beam formwork. Even though this gives good top lateral restraint, it can make the formwork complex. The column can be cast to the underside of the beams. A collar of formwork can be held around the cast column to complete the casting and support the incoming beam.
Falsework consists of temporary structures used to support a permanent structure. Falsework need to have accurate calculation. [ 4 ]
Rebar is a steel bar or mesh of steel wires used in reinforced concrete and masonry structures to strengthen and hold the concrete in tension. The surface of rebar is often patterned to improve the quality of the bond with the concrete. Rebar is necessary to add tensile strength , while concrete is strong in compression . It can support tensile loads and increase overall strength by casting rebar into concrete.
Concrete is typically used in commercial buildings and civil engineering projects, for its strength and durability. Concrete is a mix of cement and water plus an aggregate such as sand or stone. Its compression strength means it can support heavy weights. [ 5 ]
Insulating concrete forms (ICFs) cam be used for home construction. They are made by pouring concrete between rigid panels, often made out of polystyrene foam. Rebar can provide additional strength internally, and the exterior panels can remain in place once the concrete sets. It is essential to check the levels of foundation before pouring.
Bricks are laid with a mortar joint bonding them. The profile of the mortar can be varied depending on exposure or to create a specific visual effect. The most common profiles are flush (rag joint), bucket handle, weather struck, weather struck and cut and recessed.
The bonding pattern describes the alignment of the bricks. Many standard bond patterns have been defined, including stretcher bond . [ 6 ] [ 7 ] Each stretcher (brick laid lengthwise) is offset by half a brick relative to the courses above and below of English bond. Stretchers and headers are laid with alternating courses aligned to one another. American common bond is similar to the English bond but with one course of headers for every six stretcher courses. English cross bond has courses of stretchers and headers, but with the alternating stretcher courses offset by half a brick.
Flemish bond consists of alternating stretchers and headers in each course. Header bond has courses of headers offset by half a brick. Stack bond consists of bricks laid directly on top of one another with joints aligned. This is a weak bond and is likely to require reinforcement. Garden wall bond has three courses of stretchers then one course of headers. Sussex bond has three stretchers and one header in each course. | https://en.wikipedia.org/wiki/List_of_construction_methods |
Content management systems (CMS) are used to organize and facilitate collaborative content creation. Many of them are built on top of separate content management frameworks . The list is limited to notable services.
4.8.4 [ 6 ]
2024-02-13 [±]
7.11.6.0 [ 106 ]
2024-11-06 [±]
Systems listed on a light purple background are no longer in active development.
A content management framework ( CMF ) is a system that facilitates the use of reusable components or customized software for managing Web content. It shares aspects of a Web application framework and a content management system (CMS).
Below is a list of notable systems that claim to be CMFs.
Media related to Content management systems at Wikimedia Commons | https://en.wikipedia.org/wiki/List_of_content_management_systems |
In mathematics, the terms continuity , continuous , and continuum are used in a variety of related ways. | https://en.wikipedia.org/wiki/List_of_continuity-related_mathematical_topics |
This article contains a list of cooling bath mixtures. | https://en.wikipedia.org/wiki/List_of_cooling_baths |
Copper is a chemical element with the symbol Cu (from Latin : cuprum ) and the atomic number of 29. It is easily recognisable, due to its distinct red-orange color . Copper also has a range of different organic and inorganic salts , having varying oxidation states ranging from (0,I) to (III). These salts (mostly the (II) salts) are often blue to green in color, rather than the orange color copper is known for. Despite being considered a semi-noble metal , copper is one of the most common salt-forming transition metals , along with iron .
Carbonate ( carbonic acid )
(Paris Green)
Triarsenite (1,3,5,2,4,6-Trioxatriarsinane-2,4,6-triol)
(Scheele's Green)
( Chevreul's salt ) | https://en.wikipedia.org/wiki/List_of_copper_salts |
Corrosion societies are professional societies for corrosion engineers for the purpose of sharing experience and discoveries.
A cooperation between EFC and NACE was signed during the NACE Corrosion conference in San Diego, California in March 2003. The agreement improved benefit sharing between the two parties like discounts on publications and journal subscriptions. NACE and EFC will also publicize each other's event's and activities.
The Australasian Corrosion Association works with NACE in Australia and New Zealand offering accredited NACE courses in the Australasian region. The annual Corrosion & Prevention conference held in November each year presents original papers published in the Journal Corrosion & Materials . | https://en.wikipedia.org/wiki/List_of_corrosion_societies |
This is a list of corticosteroids ( glucocorticoids and mineralocorticoids ) or derivatives of cortisol ( hydrocortisone ). Most esters of these corticosteroids are not included in this list; for esters, see here instead.
The most common structural modifications in synthetic corticosteroids include 1(2)- dehydrogenation , 6α-, 9α-, 16α-, and 16β- substitution (with a halogen or methyl group ), 16α,17α- acetonidation , and 17α- and 21- esterification .
The glucocorticoid activity of progesterone and 17α-hydroxyprogesterone is very weak (>100-fold less than that of cortisol). [ 1 ]
The above list includes precursors and intermediates in corticosteroid biosynthesis .
In addition to the above, various progesterone derivative progestins such as chlormadinone acetate , cyproterone acetate , medrogestone , medroxyprogesterone acetate , megestrol acetate , and segesterone acetate possess weak glucocorticoid activity which can manifest clinically at high dosages. | https://en.wikipedia.org/wiki/List_of_corticosteroids |
Ingredients of cosmetic products are listed following International Nomenclature of Cosmetic Ingredients (INCI) .
These INCI names often differ greatly from systematic chemical nomenclature or from more common trivial names .
The below tables are sorted as follows: | https://en.wikipedia.org/wiki/List_of_cosmetic_ingredients |
This List of Cosmological Computation Software catalogs the tools and programs used by scientists in cosmological research.
In the past few decades, the accelerating technological evolution has profoundly enhanced astronomical instrumentation, enabling more precise observations and expanding the breadth and depth of data collection by several orders of magnitude. Simultaneously, the exponential growth in computational power has enabled the creation of computer simulations that reveal details with unprecedented resolution and accuracy. For performing computer simulations of the cosmos and analyzing data from both cosmological experiments and simulations, many advanced methods and computational software codes are developed every year. These codes are widely used by researchers all across the globe, in all various fields and topics of cosmology.
The computational software used in cosmology can be classified into the following major classes [ according to whom? ] :
GADGET , named "GAlaxies with Dark matter and Gas intEracT" is a code written in C++ for cosmological N-body / Smoothed-particle hydrodynamics (SPH) simulations on massively parallel computers with distributed memory . [ 15 ] Its first version was developed by German astrophysicist, Volker Springel and was published in 2000. [ 16 ] It was followed by two more official public versions, with GADGET-2 [ 17 ] [ 18 ] released in 2005 and GADGET-4 [ 19 ] [ 20 ] released in 2020, which is the most recent public version of the software suite currently. GADGET is capable to address a wide array of astrophysically interesting problems, e.g. the dynamics of the gaseous intergalactic medium, star formation and its regulation by feedback processes, colliding and merging galaxies, as well as the formation of large-scale structure in the Universe.
AREPO [ 21 ] [ 22 ] is a massively parallel code for gravitational N-body systems, hydrodynamics and magnetohydrodynamics (MHD). It is named after the enigmatic word AREPO in the Latin palindromic sentence "sator arepo tenet opera rotas" , the Sator Square . The first version of AREPO was written and published by Volker Springel in 2010, with further development by Rüdiger Pakmor and contributions by many other authors. The Arepo code utilizes an unstructured Voronoi-mesh and was designed to blend the benefits of finite-volume hydrodynamics and SPH. Primarily optimized for cosmological simulations, especially galaxy formation, Arepo supports a high dynamic range in space and time. [ 23 ]
GIZMO [ 24 ] is a flexible, massively parallel, multi-physics simulation code, written in ANSI C by Philip F. Hopkins. The code offers diverse methods to solve fluid equations. It also introduces novel methods, which optimize the resolution of simulations and minimize common errors found in previous methods that limited the accuracy of prior solvers. Originating from GADGET (hence the name "GIZMO", a play on words), the code maintains compatibility in naming/use conventions as well as input/output, making it user-friendly for those familiar with GADGET. [ 25 ]
StePS, [ 26 ] [ 27 ] which stands for "STEreographically Projected cosmological Simulations" is a freely available code that implements a novel N-body simulation method that models an infinite universe within a finite sphere with isotropic boundary conditions to follow the evolution of the large-scale structure. Unlike traditional methods, which use unrealistic periodic boundary conditions for numerical simplicity, StePS offers a more observation-aligned approach. This technique enables detailed simulations of an infinite universe using less memory and provides results that are more in line with the observed universe geometry and topology . [ 28 ]
CosmoGRaPH (Cosmological General Relativity And (Perfect fluid | Particle) Hydrodynamics) is a C++ code used to explore cosmological problems in a fully general relativistic setting. It was developed by James Mertens and Chi Tian and was published in 2016. The code implements various novel methods for numerically solving the Einstein field equations, including an N-body solver, full AMR capabilities via SAMRAI, and raytracing .
CMBFAST is a computer code, developed by Uroš Seljak and Matias Zaldarriaga (based on a Boltzmann code written by Edmund Bertschinger, Chung-Pei Ma and Paul Bode) for computing the power spectrum of the cosmic microwave background anisotropy. It is the first efficient program to do so, reducing the time taken to compute the anisotropy from several days to a few minutes by using a novel semi-analytic line-of-sight approach.
Code for Anisotropies in the Microwave Background by Antony Lewis and Anthony Challinor. The code was originally based on CMBFAST. Later several developments are made to make it a faster and more accurate and compatible with the present research. The code is written in an object oriented manner to make it more user friendly.
CMBEASY is a software package written by Michael Doran, Georg Robbers and Christian M. Müller. The code is based on the CMBFAST package. CMBEASY is fully object oriented C++ . This considerably simplifies manipulations and extensions of the CMBFAST code. In addition, a powerful Spline class can be used to easily store and visualize data. Many features of the CMBEASY package are also accessible via a graphical user interface. This may be helpful for gaining intuition, as well as for instruction purposes.
The purpose of the Cosmic Linear Anisotropy Solving System is to simulate the evolution of linear perturbations in the universe and to compute CMB and large scale structure observables. CLASS is written in plain C to achieve high performance, yet its modular structure emulates the architecture and philosophy of classes in object-oriented languages for enhanced readability and modularity. The name "CLASS" also derives from its object-oriented style, mimicking the notion of a class.
AnalizeThis is a parameter estimation package used by cosmologists. It comes with the CMBEASY package. The code is written in C++ and uses the global metropolis algorithm for estimation of cosmological parameters. The code was developed by Michael Doran, for parameter estimation using WMAP-5 likelihood. However, the code was not updated after 2008 for the new CMB experiments. Hence this package is currently not in use by the CMB research community. The package comes up with a nice GUI.
CosmoMC is a Fortran 2003 Markov chain Monte Carlo (MCMC) engine for exploring cosmological parameter space. The code does brute force (but accurate) theoretical matter power spectrum and Cl calculations using CAMB. CosmoMC uses a simple local Metropolis algorithm along with an optimized fast-slow sampling method. This fast-slow sampling method provides faster convergence for the cases with many nuisance parameters like Planck. CosmoMC package also provides subroutines for post processing and plotting of the data.
CosmoMC was written by Antony Lewis in 2002 and later several versions are developed to keep the code up-to date with different cosmological experiments. It is presently the most used cosmological parameter estimation code.
SCoPE/Slick Cosmological Parameter Estimator is a newly developed cosmological MCMC package written by Santanu Das in C language. Apart from standard global metropolis algorithm the code uses three unique technique named as 'delayed rejection' that increases the acceptance rate of a chain, 'pre-fetching' that helps an individual chain to run on parallel CPUs and 'inter-chain covariance update' that prevents clustering of the chains allowing faster and better mixing of the chains. The code is capable of faster computation of cosmological parameters from WMAP and Planck data.
Different cosmology experiments, in particular the CMB experiments like WMAP and Planck measures the temperature fluctuations in the CMB sky and then measure the CMB power spectrum from the observed skymap. But for parameter estimation the χ² is required. Therefore, all these CMB experiments come up with their own likelihood software. | https://en.wikipedia.org/wiki/List_of_cosmological_computation_software |
This is a list of people who have made noteworthy contributions to cosmology (the study of the history and large-scale structure of the universe ) and their cosmological achievements. | https://en.wikipedia.org/wiki/List_of_cosmologists |
This is a list of sovereign states and territories by per capita carbon dioxide emissions [ n 1 ] due to certain forms of human activity, based on the EDGAR database created by European Commission . The following table lists the annual per capita CO 2 emissions estimates (in kilotons of CO 2 per year) for the year 2023, as well as the change from the year 2000. [ 3 ]
The data only consider carbon dioxide emissions from the burning of fossil fuels and cement manufacture , but not emissions from land use, land-use change and forestry [ n 2 ] Over the last 150 years, estimated cumulative emissions from land use and land-use change represent approximately one-third of total cumulative anthropogenic CO 2 emissions. [ 6 ] Emissions from international shipping or bunker fuels are also not included in national figures, [ 7 ] which can make a large difference for small countries with important ports.
Measures of territorial-based emissions, also known as production-based emissions , do not account for emissions embedded in global trade, where emissions may be imported or exported in the form of traded goods, as it only reports emissions emitted within geographical boundaries. Accordingly, a proportion of the CO 2 produced and reported in Asia and Africa is for the production of goods consumed in Europe and North America. [ 8 ]
According to the review of the scientific literature conducted by the Intergovernmental Panel on Climate Change (IPCC), carbon dioxide is the most important anthropogenic greenhouse gas by warming contribution. [ 9 ] The other major anthropogenic greenhouse gases [ n 3 ] [ 10 ] : 147 [ 11 ] ) are not included in the following list, nor are humans emissions of water vapor ( H 2 O ), the most important greenhouse gases , as they are negligible compared to naturally occurring quantities. [ 12 ]
According to Science for Policy report in 2024 by the Joint Research Centre ( JRC – the European Commission's science and knowledge service ) and International Energy Agency (IEA), in 2023, global GHG emissions primarily consisted of CO 2 , resulting from the combustion of fossil fuels (73.7%). [ 3 ]
The data in the following table is extracted from EDGAR - Emissions Database for Global Atmospheric Research . [ 3 ]
CO 2 emissions are typically measured on the basis of ‘production’. This accounting method – which is sometimes referred to as ‘territorial’ emissions – is used when countries report their emissions, and set targets domestically and internationally. In addition to the commonly reported production-based emissions statisticians also calculate ‘consumption-based’ emissions. These emissions are adjusted for trade. To calculate consumption-based emissions, traded goods are tracked across the world, and whenever a good was imported all CO 2 emissions that were emitted in the production of that good are also imported, and vice versa to subtract all CO 2 emissions that were emitted in the production of goods that were exported. [ 13 ]
Consumption-based emissions reflect the consumption and lifestyle choices of a country's citizens. [ 13 ] They are national or regional emissions that have been adjusted for trade, calculated as domestic (or ‘production-based’) emissions minus the emissions generated in the production of goods and services that are exported to other countries or regions, plus emissions from the production of goods and services that are imported. [ 14 ]
Consumption-based emissions = Production-based – Exported + Imported emissions [ 14 ]
This is measured as the net import-export balance in tons of CO 2 per year. Positive values represent netimporters of CO 2 . Negative values represent net exporters of CO 2 . [ 15 ]
The data in the following table is extracted from Our World in Data database. [ 16 ] Sorting is alphabetical by country code, according to ISO 3166-1 alpha-3 . | https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita |
The following is a list of countries by computer exports . Data is for 2014, in millions of United States dollars , as reported by The Observatory of Economic Complexity . Currently the top fifteen countries are listed.
The list does not include Taiwan, due to political reasons. Its number is included in China's, even though China does not control or have influence over Taiwan. Every year, one of three laptops sold in the world is produced by one single Taiwanese company, -- Quanta Computer .
atlas.media.mit.edu - Observatory of Economic complexity - Countries that export Computers (2012) | https://en.wikipedia.org/wiki/List_of_countries_by_computer_exports |
The following is a list of countries by combustion engine exports . Data are from 2022, in billions of United States dollars , as reported by The Observatory of Economic Complexity . Currently, the top ten countries are listed: | https://en.wikipedia.org/wiki/List_of_countries_by_engine_exports |
This is a list of sovereign states and territories by greenhouse gas emissions due to certain forms of human activity, based on the EDGAR database created by European Commission . The following table lists the 1970, 1990, 2000, 2010, 2020, 2021, 2022, and 2023 annual GHG [ n 1 ] emissions estimates (in kilotons of CO 2 equivalent per year) along with a list of calculated emissions per capita (in metric tons of CO 2 equivalent per year). The data include carbon dioxide , methane and nitrous oxide from all sources, including agriculture and land use change. They are measured in carbon dioxide-equivalents over a 100-year timescale.
The Intergovernmental Panel on Climate Change (IPCC) 6th assessment report finds that the "Agriculture, Forestry and Other Land Use (AFOLU)" sector on average, accounted for 13–21% of global total anthropogenic GHG emissions in the period 2010–2019. [ 4 ] Land use change drivers net AFOLU CO 2 emission fluxes, with deforestation being responsible for 45% of total AFOLU emissions. In addition to being a net carbon sink and source of GHG emissions, land plays an important role in climate through albedo effects, evapotranspiration, and aerosol loading through emissions of volatile organic compounds. [ 4 ] The IPCC report finds that the LULUCF sector offers significant near-term mitigation potential while providing food, wood and other renewable resources as well as biodiversity conservation. Mitigation measures in forests and other natural ecosystems provide the largest share of the LULUCF mitigation potential between 2020 and 2050. Among various LULUCF activities, reducing deforestation has the largest potential to reduce anthropogenic GHG emissions, followed by carbon sequestration in agriculture and ecosystem restoration including afforestation and reforestation. [ 4 ] Land use change emissions can be negative. [ n 2 ] [ 6 ]
In 2023, global GHG emissions reached 53.0 Gt CO 2 eq (without Land Use, land Use Change and Forestry). The 2023 data represent the highest level recorded and experienced an increase of 1.9% or 994 Mt CO 2 eq compared to the levels in 2022. The majority of GHG emissions consisted of fossil CO 2 accounting for 73.7% of total emissions. [ 7 ]
China , the United States , India , the EU27 , Russia and Brazil were the world’s largest GHG emitters in 2023. Together they account for 49.8% of global population, 63.2% of global gross domestic product, 64.2% of global fossil fuel consumption and 62.7% of global GHG emissions. Among these top emitters, in 2023 China , India , Russia and Brazil increased their emissions compared to 2022, with India having the largest increase in relative terms (+ 6.1%) and China the largest absolute increase by 784 Mt CO 2 eq . [ 7 ]
GHG emissions from the top 10 countries with the highest emissions accounted for almost two thirds of the global total. Since 2006, China has been emitting more CO 2 than any other country. [ 8 ] [ 9 ] [ 10 ]
However, the main disadvantage of measuring total national emissions is that it does not take population size into account. China has the largest CO 2 and GHG emissions in the world, but also the second largest population. Some argue that for a fair comparison, emissions should be analyzed in terms of the amount of CO 2 and GHG per capita. [ 11 ]
Considering GHG per capita emissions in 2023, China's levels (11.11) are 53% higher than those of the European Union (7.26), are almost two-thirds those of the United States (17.61) and less than a sixth of those of Palau (65,29) – the country with the highest emissions of GHG per capita in 2023. [ 7 ]
Measures of territorial-based emissions, also known as production-based emissions , do not account for emissions embedded in global trade, where emissions may be imported or exported in the form of traded goods, as it only reports emissions emitted within geographical boundaries. Accordingly, a proportion of the CO 2 produced and reported in Asia and Africa is for the production of goods consumed in Europe and North America. [ 12 ]
According to the review of the scientific literature conducted by the Intergovernmental Panel on Climate Change (IPCC), carbon dioxide is the most important anthropogenic greenhouse gas by warming contribution. [ 13 ] Greenhouse gases (GHG) – primarily carbon dioxide but also others, including methane and chlorofluorocarbons – trap heat in the atmosphere, leading to global warming. Higher temperatures then act on the climate, with varying effects. For example, dry regions might become drier while, at the poles, the ice caps are melting, causing higher sea levels. In 2016, the global average temperature was already 1.1 °C above pre-industrial levels. [ 14 ]
The data in the following table is extracted from EDGAR - Emissions Database for Global Atmospheric Research . [ 7 ]
Sorting is in descending order, by GHG emissions in 2023, starting with the maximum value — China ( 15 943 986 .55 kt CO 2 eq = 100%). Percentages for GHG emissions per capita 2023 are also related to the maximum value — Palau ( 65.29 t CO 2 eq = 100%).
Sorting is in descending order, by total GHG emissions 1970-2023, starting with the maximum value — China ( 370 328 794 .88 kt CO 2 eq = 100%). Percentages for GHG emissions 2023 are also related to the maximum value — China ( 15 943 986 .55 kt CO 2 eq = 100%). | https://en.wikipedia.org/wiki/List_of_countries_by_greenhouse_gas_emissions |
This is a list of sovereign states and territories by per capita greenhouse gas emissions due to certain forms of human activity, based on the EDGAR database created by European Commission . The following table lists the 1970, 1990, 2000, 2010, 2020, 2021, 2022 and 2023 annual per capita GHG [ n 1 ] emissions estimates (in metric tons of CO 2 equivalent per year). The data include carbon dioxide (CO 2 ), methane ( CH 4 ) and nitrous oxide ( N 2 O ) from all sources, including agriculture and land use change. They are measured in carbon dioxide-equivalents over a 100-year timescale. [ n 2 ]
The Intergovernmental Panel on Climate Change (IPCC) 6th assessment report finds that the "Agriculture, Forestry and Other Land Use (AFOLU)" sector on average, accounted for 13–21% of global total anthropogenic GHG emissions in the period 2010–2019. [ 3 ] Land use change drivers net AFOLU CO 2 emission fluxes, with deforestation being responsible for 45% of total AFOLU emissions. In addition to being a net carbon sink and source of GHG emissions, land plays an important role in climate through albedo effects, evapotranspiration, and aerosol loading through emissions of volatile organic compounds. [ 3 ] The IPCC report finds that the LULUCF sector offers significant near-term mitigation potential while providing food, wood and other renewable resources as well as biodiversity conservation. Mitigation measures in forests and other natural ecosystems provide the largest share of the LULUCF mitigation potential between 2020 and 2050. Among various LULUCF activities, reducing deforestation has the largest potential to reduce anthropogenic GHG emissions, followed by carbon sequestration in agriculture and ecosystem restoration including afforestation and reforestation. [ 3 ] Land use change emissions can be negative. [ n 3 ] [ 5 ]
According to Science for Policy report in 2024 by the Joint Research Centre (JRC – the European Commission’s science and knowledge service) and International Energy Agency (IEA), global per-capita GHG emissions in 2023 increased by 0.9% to reach 6.59 t CO 2 eq /cap, a value still 0.9% lower than in 2019 (6.65 t CO 2 eq /cap), but have increased by about 7.3% from 6.14 t CO 2 eq /cap to 6.59 t CO 2 eq /cap between 1990 and 2023. [ 6 ]
However, the main disadvantage of measuring total national emissions is that it does not take population size into account. China has the largest CO 2 and GHG emissions in the world, but also the second largest population. Some argue that for a fair comparison, emissions should be analyzed in terms of the amount of CO 2 and GHG per capita. [ 7 ]
Considering GHG per capita emissions in 2023, China's levels (11.11) are almost two-thirds those of the United States (17.61) and almost a sixth of those of Palau (65,29) – the country with the highest emissions of GHG per capita in 2023. [ 6 ]
Measures of territorial-based emissions, also known as production-based emissions , do not account for emissions embedded in global trade, where emissions may be imported or exported in the form of traded goods, as it only reports emissions emitted within geographical boundaries. Accordingly, a proportion of the CO 2 produced and reported in Asia and Africa is for the production of goods consumed in Europe and North America. [ 8 ]
According to the review of the scientific literature conducted by the Intergovernmental Panel on Climate Change (IPCC), carbon dioxide is the most important anthropogenic greenhouse gas by warming contribution. [ 9 ] The European Union is at the forefront of international efforts to reduce greenhouse gas emissions and thus safeguard the planet's climate. Greenhouse gases (GHG) – primarily carbon dioxide but also others, including methane and chlorofluorocarbons – trap heat in the atmosphere, leading to global warming. Higher temperatures then act on the climate, with varying effects. For example, dry regions might become drier while, at the poles, the ice caps are melting, causing higher sea levels. In 2016, the global average temperature was already 1.1 °C above pre-industrial levels. [ 10 ]
The data in the following table is extracted from EDGAR – Emissions Database for Global Atmospheric Research . [ 6 ] Sorting is alphabetical by country code, according to ISO 3166-1 alpha-3 . | https://en.wikipedia.org/wiki/List_of_countries_by_greenhouse_gas_emissions_per_capita |
This is a list of countries by stem cell research trials for the purpose of commercializing treatments as of June 2020, using data from ClinicalTrials.gov . [ 1 ] | https://en.wikipedia.org/wiki/List_of_countries_by_stem_cell_research_trials |
This is a list of all crewed spacecraft types that have flown into space, including sub-orbital flights above 80 km, space stations that have been visited by at least one crew member, and spacecraft currently planned to operate with crews in the future. [ 1 ] It does not contain spacecraft that have only flown uncrewed and have retired from service, even if they were designed for crewed flight, such as Buran , or crewed flights by spacecraft below 80 km. There is some debate concerning the height at which space is reached (the Karman Line ): the Fédération Aéronautique Internationale (FAI) recognizes 100 km, while NASA and the USAF recognize this as 50 miles (approx 80 km). [ 2 ]
Since the first crewed spaceflight of Vostok 1 in 1961 there have been 13 types of spacecraft that have made crewed flights into space – nine American, three Russian, and one Chinese. There are currently five operational crewed spacecraft, which form the first part of the list below; the eight retired spacecraft types are listed in the next section; and crewed spacecraft currently in development are listed last. Space stations are listed beneath each appropriate section, dates of operation reflect when the first and last crews visited, not when they were launched and deorbited. There are currently two space stations in orbit around Earth, the International Space Station and the Chinese Tiangong space station .
Manned spacecraft are designed to support human life for the human spaceflight portion of the mission. Spacecraft for human spaceflight must have a human-rating certification as fit for purpose. Manned spacecraft must have a pressurized, breathable atmosphere (usually between 345 mbar and 1 bar (1 atmosphere )) and be temperature-regulated (usually 20 to 24 °C (68 to 75 °F)). Manned spacecraft include space capsules , spaceplanes , and space stations .
Russian three person Earth orbital spacecraft; [ 3 ] Early versions were operated by the Soviet Union and later versions by Russia after 1991. Soyuz has completed over 150 crewed spaceflights, including two emergency sub-orbital flights: Soyuz 18a and Soyuz MS-10 . There have been two spacecraft losses resulting in the deaths of four cosmonauts, Soyuz 1 and Soyuz 11 . Soyuz is the only spacecraft to have successfully saved the lives of a crew using the rocket launch escape system , when in 1983 Soyuz T-10-1 exploded on the launchpad. This spacecraft type has flown into space more times than any other spacecraft. [ 4 ]
Chinese three-person Earth orbital spacecraft. Shenzhou is China 's first crewed spacecraft. On 15 October 2003, Yang Liwei was carried into space by Shenzhou 5 becoming China's first Taikonaut . [ 5 ] The spacecraft has gone on to fly crews to China's Tiangong-1 and Tiangong-2 space labs. Since Jun 2021, Shenzhou has been used as the vehicle to send crews to China's new modular Tiangong space station and back. [ 6 ] As of December 2023, Shenzhou has made 12 successful crewed spaceflights.
United States four-person (initially seven) Earth orbital spacecraft designed by SpaceX to transport astronauts to the International Space Station under the NASA Commercial Crew Contract ( CCDev ). As of April 2025, Crew Dragon has made 17 crewed spaceflights. The first crewed flight, Crew Dragon Demo-2 , launched on 30 May 2020 and returned to Earth on 2 August 2020. This was the first time an American spacecraft had sent astronauts to orbit since the final Space Shuttle flight in July 2011. [ 7 ] The first operational flight of the Crew Dragon launched on 15 November 2020 with SpaceX Crew-1 .
New Shepard is a six-person capsule for suborbital space tourism in the United States . It is launched by a reusable booster and can fly with or without crew. Uncrewed flights started in 2015. The first crewed test flight flew on 20 July 2021. [ 8 ] As of December 2023 there have been 24 flights, including six crewed flights carrying a total of 32 passengers into space.
The Boeing CST-100 Starliner is a United States five-person (initially seven) Earth orbital spacecraft designed to transport astronauts to the International Space Station under the NASA Commercial Crew Program . Following several technical problems 1 on the first uncrewed test flight in December 2019, a second uncrewed test flight launched in May 2022. The following crewed flight test (CFT) launched in June 2024, carrying astronauts Suni Williams and Butch Wilmore to the International Space Station. After experiencing thruster issues during its approach and docking, the astronauts successfully completed their mission at the ISS and departed the station. Due to ongoing assessments and mission adjustments, the Starliner landed uncrewed. The Crew-9 mission, carrying astronauts Nick Hague, Suni Williams, Butch Wilmore, and cosmonaut Aleksandr Gorbunov, splashed down in the Gulf of Mexico off the coast of Florida on March 18, 2025. This landing marked the end of a long space saga for Williams and Wilmore, who arrived at the ISS aboard the Starliner. [ 9 ] [ 10 ] [ 11 ]
Multinational low Earth orbit modular space station. The International Space Station is a joint project among five participating space agencies: NASA , Roscosmos , JAXA , European Space Agency (ESA), and Canadian Space Agency (CSA). [ 12 ] Following the uncrewed initial assembly from 1998 to 2000, it has been continuously crewed since November 2000. As of 4 March 2024, ISS has been visited by 111 crewed spacecraft (68 Soyuz, 35 Space Shuttle, and 9 Crew Dragon). The ISS is the largest space station yet constructed. It is planned to operate until 2028, with a possible extension to 2030. [ 13 ]
Chinese low Earth orbit modular space station. The Tianhe core module was launched on 29 April 2021. The first crewed flight Shenzhou 12 with 3 astronauts arrived at the station in June 2021. The space station has three modules: the Tianhe core module , and two Laboratory Cabin Modules . The Wentian module docked with the station on 24 July 2022, and the Mengtian module docked on 31 October 2022.
Soviet single-person Earth orbital spacecraft 6 flights. [ 14 ] On 12 April 1961 Vostok 1 carried the first human into space, Cosmonaut Yuri Gagarin . [ 15 ] On 16 June 1963, Vostok 6 carried the first woman into space, Cosmonaut Valentina Tereshkova . [ 16 ]
United States single-person Earth orbital spacecraft 6 flights (including 2 sub-orbital). [ 17 ] Mercury was the United States first crewed spacecraft. On 5 May 1961 Mercury-Redstone 3 carried the first American, Alan Shepard , into space on a sub-orbital flight. On 20 February 1962, Mercury-Atlas 6 carried the first American, John Glenn , into Earth orbit. [ 18 ]
United States single seat, air-launched sub-orbital spaceplane; two X-15 flights above the 100 km Kármán line occurred in 1963, an additional 11 flights between 1962 and 1968 reached altitudes between 80 and 100 km which were recognized as spaceflights by U.S. authorities. [ 19 ]
Soviet three person Vostok derivative made 2 flights. [ 20 ] On 18 March 1965, Alexei Leonov performed the first spacewalk in history, from Voskhod 2 . [ 21 ]
United States two person Earth orbital spacecraft which made 10 flights. [ 22 ] On 3 June 1965, Ed White made America's first spacewalk during Gemini 4 . [ 23 ]
United States three-person lunar-capable spacecraft. 15 flights; including nine lunar missions (with six lunar landings). It was the Apollo spacecraft that enabled America to win the Space Race . In December 1968, Apollo 8 was the first crewed spacecraft to orbit the Moon. On 21 July 1969, Neil Armstrong , the Commander of Apollo 11 , and Buzz Aldrin became the first men to walk on the Moon. [ 24 ] The Apollo Spacecraft comprised:
United States eight person Earth orbital spacecraft; first orbit-capable spaceplane ; first reusable orbital spacecraft. Largest cargo capacity to orbit at the time. 135 spaceflights were made in six shuttles; Enterprise , Columbia , Challenger , Discovery , Atlantis , and Endeavour , of which two ( Challenger and Columbia ) were destroyed resulting in the deaths of 14 astronauts during missions STS-51-L and STS-107 . [ 27 ]
United States privately-developed single pilot, air-launched sub-orbital spaceplane; three flights above the Kármán line occurred in 2004.
[ 28 ]
United States eight person air-launched sub-orbital space plane operated by Virgin Galactic aimed at the space tourism market. On 31 October 2014 during a test flight, VSS Enterprise , the first SpaceShipTwo craft, broke up in flight and crashed in the Mojave Desert . [ 29 ] [ 30 ] [ 31 ] [ 32 ] One pilot was killed. [ 33 ] [ 34 ] The second SpaceShipTwo craft, VSS Unity , was completed in 2016 and used until its retirement in 2024. [ 35 ] On 13 December 2018, SpaceShipTwo flew to an altitude of 82.7 km, which is recognized as space by the FAA , NASA , and the USAF (although not the Fédération Aéronautique Internationale ). [ 36 ] This was the first time an American spacecraft had sent astronauts to space since the final Space Shuttle flight in 2011. On 11 July 2021 a fourth test flight was made above 80 km with six crew aboard, including the company owner Richard Branson . [ 37 ] SpaceShipTwo made 12 successful crewed spaceflights in 13 attempts. The last flight of VSS Unity took place on 8 June 2024, marking the spacecraft's retirement.
Soviet / Russian low Earth orbit space stations. [ 38 ] Salyut 1 (1 crew 1971), Salyut 4 (2 crews 1975), Salyut 6 (6 crews 1977–1981), and Salyut 7 (12 crews 1982–1986). All now de-orbited. [ 39 ]
Soviet military reconnaissance low Earth orbit space stations. Badged as Salyut 3 (1 crew 1974), and Salyut 5 (2 crews 1976–1977), as disinformation. Both now deorbited. [ 39 ]
United States low Earth orbit space station. First United States space station. Visited by 3 crews 1973–1974. It deorbited in 1979. [ 40 ]
Soviet / Russian low Earth orbit modular space station. The first modular space station in history. Twenty-eight crews 1986–2000. Mir was visited by 29 Soyuz and 7 Space Shuttle missions. Mir was deorbited in 2001. [ 41 ]
Chinese low Earth orbit space laboratories. Tiangong 1 was China's first space station; launched in 2011, visited by two crews 2012–2013, deorbited in 2018. Tiangong 2 was launched in 2016, visited by one crew in 2016, deorbited in 2019. Both vehicles were single-module laboratories, precursors to the modular Tiangong space station , which has modules derived from Tiangong 1 and 2.
A spacecraft capable of lunar missions with a crew of four, planned to be used as part of NASA 's Artemis program . Consisting of two components – a Crew Module (CM) manufactured by Lockheed Martin , and a European Service Module (ESM) manufactured by Airbus Defence and Space – the spacecraft are designed to support crewed exploration beyond low Earth orbit . Orion is equipped with solar power , an automated docking system , and glass cockpit interfaces modeled after those used in the Boeing 787 Dreamliner , and can support a crew of six in low Earth orbit and a crew of four in lunar orbit, up to 21 days undocked and up to six months docked. A single AJ10 engine provides the spacecraft's primary propulsion, while eight R-4D-11 engines and six pods of custom reaction control system (RCS) engines developed by Airbus provide the spacecraft's secondary propulsion. Although compatible with other launch vehicles , Orion is primarily designed to launch atop the Space Launch System (SLS) rocket. The first mission on that flew a fully configured Orion spacecraft and service module was Artemis I . This flight, however, was not a crewed mission and served the purpose of testing the systems of the spacecraft in the environment it was designed for. The first crewed mission Artemis II is planned for 2026 and will slingshot around the Moon. The following crewed Artemis III flight is planned for 2027 and will be a lunar landing mission.
Planned to be a fully reusable interplanetary spacecraft capable of carrying 100 passengers or cargo. Primarily designed for Mars missions it is to be capable of landing on all rocky planets or moons in the Solar System except Venus . [ 42 ] For Earth launches Starship will need a two-stage configuration with the addition of a powerful first stage booster called Super-Heavy. Flights from all other planetary bodies will not require a first stage booster. Starship will require refuelling in Earth orbit to enable it to reach other Solar System destinations. [ 43 ] [ 44 ] Uncrewed test flights commenced in 2020 from Boca Chica, Texas. A custom crewed lunar version of Starship— Starship HLS —was selected in 2021 from three companies that developed design proposals for NASA's Human Landing System for NASA 's Artemis program , with a view to land one uncrewed mission plus one crewed mission on the Moon no earlier than 2025. [ 45 ] [ 46 ] SpaceX plans at least six variants of Starship, two of them intended to carry crew: Cargo flights, crewed flights (except HLS), a fuel depot, [ 47 ] a tanker version, expendable starships, and HLS.
A three-person Earth orbital spacecraft intended to be the first crewed spacecraft of the Indian Human Spaceflight Programme . Gaganyaan will be capable of operating at low Earth orbit for up to seven days. The upgraded version will be equipped with rendezvous and docking capabilities. Its first crewed flight is planned for first quarter of 2027, and four Indian astronauts have begun flight training in Russia. [ 48 ]
The Mengzhou spacecraft, developed by the China Aerospace Science and Technology Corp. (CASC) is a six-person, partially reusable lunar-capable spacecraft, aiming to succeed the Shenzhou .
An uncrewed test flight took place on 5 May 2020, with a crewed flight to low earth orbit possible by 2027 using a two-stage variant of the under-development Long March 10 rocket. [ 49 ] Lunar missions by the new spacecraft are expected in the 2030s with an initial lunar mission possible by 2030. [ 49 ] [ 50 ]
A new Chinese crewed lunar lander called Lanyue is also currently under-development by the China Academy of Space Technology . [ 49 ]
United States seven-person Earth orbital space plane. [ 51 ] An uncrewed cargo version is scheduled to fly in space in 2025, with a crewed version to eventually follow. [ 52 ]
Russian four-person lunar-capable spacecraft to enable the retirement of Soyuz. The first uncrewed and crewed flight is planned for 2028. [ 53 ] [ 54 ]
Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster → Local Hole → Observable universe → Universe Each arrow ( → ) may be read as "within" or "part of". | https://en.wikipedia.org/wiki/List_of_crewed_spacecraft |
In the international petroleum industry , crude oil products are traded on various oil bourses based on established chemical profiles, delivery locations, and financial terms. The chemical profiles, or crude oil assays , specify important properties such as the oil's API gravity . The delivery locations are usually sea ports close to the oil fields from which the crude was obtained (and new fields are constantly being explored), and the pricing is usually quoted based on FOB ( free on board , without consideration of final delivery costs).
The three most quoted oil products are North America 's West Texas Intermediate crude (WTI), North Sea Brent Crude , and the UAE Dubai Crude , and their pricing is used as a barometer for the entire petroleum industry, although, in total, there are 46 key oil exporting countries. Brent Crude is typically priced at about $2 over the WTI Spot price, which is typically priced $5 to $6 above the EIA's Imported Refiner Acquisition Cost (IRAC) and OPEC Basket prices. WTI and Brent are quoted FOB specific locations, not FOB the oilfields. For WTI, the delivery point is Cushing, OK; for Brent, it is Sullom Voe , located in Shetland , an island archipelago north of mainland Scotland.
Although crude oil assays evaluate various chemical properties of the oil, the two most important properties determining a crude's value are its density (measured as API specific gravity) and its sulphur content (measured per mass). Crude oil is considered " heavy " if it has long hydrocarbon chains, or " light " if it has short hydrocarbon chains: an API gravity of 34 or higher is "light", between 31 and 33 is "medium", and 30 or below is "heavy".
Crude is considered " sweet " if it is low in sulphur content (< 0.5%/weight), or " sour " if high (> 1.0%/weight). Generally, the higher the API gravity (the "lighter" it is), the more valuable the crude. | https://en.wikipedia.org/wiki/List_of_crude_oil_products |
This is a list of filesystems with support for filesystem-level encryption . Not to be confused with full-disk encryption . | https://en.wikipedia.org/wiki/List_of_cryptographic_file_systems |
Convicted computer criminals are people who are caught and convicted of computer crimes such as breaking into computers or computer networks . [ 1 ] Computer crime can be broadly defined as criminal activity involving information technology infrastructure, including illegal access (unauthorized access), illegal interception (by technical means of non-public transmissions of computer data to, from or within a computer system), data interference (unauthorized damaging, deletion, deterioration, alteration or suppression of computer data), systems interference (interfering with the functioning of a computer system by inputting, transmitting, damaging, deleting, deteriorating, altering or suppressing computer data), misuse of devices, forgery (or identity theft ) and electronic fraud. [ 2 ]
In the infancy of the hacker subculture and the computer underground, [ 3 ] criminal convictions were rare because there was an informal code of ethics that was followed by white hat hackers . [ 4 ] Proponents of hacking claim to be motivated by artistic and political ends, but are often unconcerned about the use of criminal means to achieve them. [ 5 ] White hat hackers break past computer security for non-malicious reasons and do no damage, akin to breaking into a house and looking around. [ 6 ] They enjoy learning and working with computer systems, and by this experience gain a deeper understanding of electronic security. [ 6 ] As the computer industry matured, individuals with malicious intentions ( black hats ) would emerge to exploit computer systems for their own personal profit. [ 6 ]
Convictions of computer crimes, or hacking, began as early as 1984 with the case of The 414s from the 414 area code in Milwaukee . In that case, six teenagers broke into a number of high-profile computer systems, including Los Alamos National Laboratory , Sloan-Kettering Cancer Center and Security Pacific Bank . On May 1, 1984, one of the 414s, Gerald Wondra , was sentenced to two years of probation. [ 7 ] In May 1986, the first computer trespass conviction to result in a jail sentence was handed down to Michael Princeton Wilkerson, who received two weeks in jail for his infiltration of Microsoft , Sundstrand Corp. , Kenworth Truck Co . and Resources Conservation Co. [ 8 ]
In 2006, a prison term of nearly five years was handed down to Jeanson James Ancheta , who created hundreds of zombie computers to do his bidding via giant bot networks or botnets . [ 9 ] He then sold the botnets to the highest bidder, who in turn used them for denial-of-service (DoS) attacks . [ 10 ]
As of 2012 [update] , the longest sentence for computer crimes is that of Albert Gonzalez for 20 years. [ 11 ] The next longest sentences are those of 13 years for Max Butler , [ 12 ] 108 months for Brian Salcedo in 2004 and upheld in 2006 by the U.S. 4th Circuit Court of Appeals, [ 13 ] [ 14 ] and 68 months for Kevin Mitnick in 1999. [ 15 ]
He is a co-creator of Trojan horse SpyEye . He stole from 217 American banks in total stealing $400 million and is alleged to have donated all the money to Africa and Palestine, though Trial documents did not mention any donations or charity activities. [ 26 ] Despite much false information on the internet Bendelladj did not get sentenced to death, and claims saying he donated any money to charity is almost impossible to verify. [ 27 ] The SpyEye software was also sold to other hackers and used as part of a botnet. | https://en.wikipedia.org/wiki/List_of_cybercriminals |
This is a list of cybersecurity information technologies . Cybersecurity concerns all technologies that store, manipulate, or move computer data , such as computers , data networks , and all devices connected to or included in said networks, such as routers and switches . All information technology devices and facilities need to be secured against intrusion , unauthorized use, and vandalism . Users of information technology are to be protected from theft of assets, extortion , identity theft , loss of privacy, damage to equipment, business process compromise, and general disruption. The public should be protected against acts of cyberterrorism , such as compromise or denial of service .
Cybersecurity is a major endeavor in the IT industry . There are a number of professional certifications given for cybersecurity training and expertise . [ 1 ] Billions of dollars are spent annually on cybersecurity, but no computer or network is immune from attacks or can be considered completely secure.
This article attempts to list important Wikipedia articles about cybersecurity.
Introductory articles about cybersecurity subjects:
The art of secret writing or code. A "plaintext" message is converted by the sender to "ciphertext" by means of a mathematical algorithm that uses a secret key. The receiver of the message then reverses the process and converts the ciphertext back to the original plaintext. [ 6 ]
Steganography is the process of hiding data within other data, most commonly by hiding data inside images. [ 8 ]
The process by which a potential client is granted authorized use of an IT facility by proving its identity. [ 10 ]
A framework for managing digital certificates and encryption keys.
Computerized utilities designed to study and analyze the security of IT facilities and/or break into them on an unauthorized and potentially criminal basis. [ 11 ]
Modes of potential attacks on IT facilities. [ 12 ]
Security exploits affecting computers. [ 13 ]
Violation of the law by means of breaking into and/or misusing IT facilities. Laws that attempt to prevent these crimes. [ 14 ]
Countries and their governments that use, misuse, and/or violate IT facilities to achieve national goals. [ 15 ]
The securing of networked computers, mobile devices and terminals. [ 16 ]
The protection of the means by which data is moved from one IT facility to another. [ 17 ]
The securing of IT facilities that manipulate data, such as computer servers, often by means of specialized cybersecurity hardware. [ 18 ]
The protection of data in its non-moving state, usually on magnetic or optical media or in computer memory. [ 19 ]
The processes by which security technology is monitored for faults, deployed and configured, measured for its usage, queried for performance metrics and log files, and/or monitored for intrusions. [ 20 ]
Officially agreed architectures and conceptual structures for designing, building, and conducting cybersecurity. [ 21 ] [ 22 ] | https://en.wikipedia.org/wiki/List_of_cybersecurity_information_technologies |
This is a list of cytochrome P450 modulators , or inhibitors and inducers of cytochrome P450 enzymes .
In alphabetical order.
German Chamomile
Dandelion
Kava
Peppermint
Turmeric
Includes information found online including these sites: | https://en.wikipedia.org/wiki/List_of_cytochrome_P450_modulators |
This is a list of utilities for performing data erasure . | https://en.wikipedia.org/wiki/List_of_data-erasing_software |
The List of data references for chemical elements is divided into datasheets that give values for many properties of the elements , together with various references. Each datasheet is sequenced by atomic number . | https://en.wikipedia.org/wiki/List_of_data_references_for_chemical_elements |
The following database management systems and other software use multiversion concurrency control . | https://en.wikipedia.org/wiki/List_of_databases_using_MVCC |
This is a list of debuggers : computer programs that are used to test and debug other programs.
Software specializing in debugging of frame rendering. | https://en.wikipedia.org/wiki/List_of_debuggers |
At least 218 companies have manufactured hard disk drives (HDDs) since 1956. Most of that industry has vanished through bankruptcy or mergers and acquisitions . None of the first several entrants (including IBM , who invented the HDD ) continue in the industry today. Only three manufacturers have survived— Seagate , Toshiba and Western Digital (WD)—all of which grew at least in part through mergers and acquisitions. [ 1 ]
The following is a partial list of defunct hard disk manufacturers. There are currently 119 manufacturers in this incomplete list. | https://en.wikipedia.org/wiki/List_of_defunct_hard_disk_manufacturers |
During the dot-com / internet bubble of the late 1990s and early 2000, the proliferation of many dot-com start-up companies created a secondary bubble in the telecommunications / computer networking infrastructure and telecommunications service provider markets. Venture capital and high tech companies rushed to build next generation infrastructure equipment for the expected explosion of internet traffic. As part of that investment fever, network processors were seen as a method of dealing with the desire for more network services and the ever-increasing data-rates of communication networks.
It has been estimated that dozens of start-up companies were created in the race to build the processors that would be a component of the next generation telecommunications equipment. Once the internet investment bubble burst, the telecom network upgrade cycle was deferred for years (perhaps for a decade). As a result, the majority of these new companies went bankrupt.
As of 2007, the only companies that are shipping network processors in sizeable volumes are Cisco Systems , Marvell , Freescale , Cavium Networks and AMCC . | https://en.wikipedia.org/wiki/List_of_defunct_network_processor_companies |
There are many alternatives to the classical calculus of Newton and Leibniz ; for example, each of the infinitely many non-Newtonian calculi. [ 1 ] Occasionally an alternative calculus is more suited than the classical calculus for expressing a given scientific or mathematical idea. [ 2 ] [ 3 ] [ 4 ]
The table below is intended to assist people working with the alternative calculus called the "geometric calculus" (or its discrete analog). Interested readers are encouraged to improve the table by inserting citations for verification, and by inserting more functions and more calculi.
In the following table;
ψ ( x ) = Γ ′ ( x ) Γ ( x ) {\displaystyle \psi (x)={\frac {\Gamma '(x)}{\Gamma (x)}}} is the digamma function ,
K ( x ) = e ζ ′ ( − 1 , x ) − ζ ′ ( − 1 ) = e z − z 2 2 + z 2 ln ( 2 π ) − ψ ( − 2 ) ( z ) {\displaystyle \operatorname {K} (x)=e^{\zeta ^{\prime }(-1,x)-\zeta ^{\prime }(-1)}=e^{{\frac {z-z^{2}}{2}}+{\frac {z}{2}}\ln(2\pi )-\psi ^{(-2)}(z)}} is the K-function ,
( ! x ) = Γ ( x + 1 , − 1 ) e {\displaystyle (!x)={\frac {\Gamma (x+1,-1)}{e}}} is subfactorial ,
B a ( x ) = − a ζ ( − a + 1 , x ) {\displaystyle B_{a}(x)=-a\zeta (-a+1,x)} are the generalized to real numbers Bernoulli polynomials . | https://en.wikipedia.org/wiki/List_of_derivatives_and_integrals_in_alternative_calculi |
List of desiccants : [ 1 ] | https://en.wikipedia.org/wiki/List_of_desiccants |
The following is a list of major desktop publishing software. For comparisons between the desktop publishing software, such as operating system or cloud support, licensing, and other features, see Comparison of desktop publishing software . | https://en.wikipedia.org/wiki/List_of_desktop_publishing_software |
This is a list of differential geometry topics. See also glossary of differential and metric geometry and list of Lie group topics .
See also multivariable calculus , list of multivariable calculus topics | https://en.wikipedia.org/wiki/List_of_differential_geometry_topics |
During the 1980s, most digital forensic investigations consisted of "live analysis", examining digital media directly using non-specialist tools. In the 1990s, several freeware and other proprietary tools (both hardware and software) were created to allow investigations to take place without modifying media. This first set of tools mainly focused on computer forensics , although in recent years similar tools have evolved for the field of mobile device forensics. [ 1 ] This list includes notable examples of digital forensic tools.
Memory forensics tools are used to acquire or analyze a computer's volatile memory (RAM). They are often used in incident response situations to preserve evidence in memory that would be lost when a system is shut down, and to quickly detect stealthy malware by directly examining the operating system and other running software in memory.
Mobile forensics tools tend to consist of both a hardware and software component. Mobile phones come with a diverse range of connectors, the hardware devices support a number of different cables and perform the same role as a write blocker in computer devices.
Software forensics is the science of analyzing software source code or binary code to determine whether intellectual property infringement or theft occurred. It is the centerpiece of lawsuits, trials, and settlements when companies are in dispute over issues involving software patents, copyrights, and trade secrets. Software forensics tools can compare code to determine correlation, a measure that can be used to guide a software forensics expert. | https://en.wikipedia.org/wiki/List_of_digital_forensics_tools |
Artificial life ( ALife or A-Life ) is a field of study wherein researchers examine systems related to natural life , its processes, and its evolution, through the use of simulations with computer models , robotics , and biochemistry . [ 1 ] The discipline was named by Christopher Langton , an American computer scientist , in 1986. [ 2 ] In 1987, Langton organized the first conference on the field, in Los Alamos, New Mexico . [ 3 ] There are three main kinds of alife, [ 4 ] named for their approaches: soft , [ 5 ] from software ; hard , [ 6 ] from hardware ; and wet , from biochemistry. Artificial life researchers study traditional biology by trying to recreate aspects of biological phenomena. [ 7 ] [ 8 ]
Artificial life studies the fundamental processes of living systems in artificial environments in order to gain a deeper understanding of the complex information processing that define such systems. These topics are broad, but often include evolutionary dynamics , emergent properties of collective systems, biomimicry , as well as related issues about the philosophy of the nature of life and the use of lifelike properties in artistic works. [ citation needed ]
The modeling philosophy of artificial life strongly differs from traditional modeling by studying not only "life as we know it" but also "life as it could be". [ 9 ]
A traditional model of a biological system will focus on capturing its most important parameters. In contrast, an alife modeling approach will generally seek to decipher the most simple and general principles underlying life and implement them in a simulation. The simulation then offers the possibility to analyse new and different lifelike systems.
Vladimir Georgievich Red'ko proposed to generalize this distinction to the modeling of any process, leading to the more general distinction of "processes as we know them" and "processes as they could be". [ 10 ]
At present, the commonly accepted definition of life does not consider any current alife simulations or software to be alive, and they do not constitute part of the evolutionary process of any ecosystem . However, different opinions about artificial life's potential have arisen:
Program-based simulations contain organisms with a "genome" language. This language is more often in the form of a Turing complete computer program than actual biological DNA. Assembly derivatives are the most common languages used. An organism "lives" when its code is executed, and there are usually various methods allowing self-replication . Mutations are generally implemented as random changes to the code. Use of cellular automata is common but not required. Another example could be an artificial intelligence and multi-agent system/program .
Individual modules are added to a creature. These modules modify the creature's behaviors and characteristics either directly, by hard coding into the simulation (leg type A increases speed and metabolism), or indirectly, through the emergent interactions between a creature's modules (leg type A moves up and down with a frequency of X, which interacts with other legs to create motion). Generally, these are simulators that emphasize user creation and accessibility over mutation and evolution.
Organisms are generally constructed with pre-defined and fixed behaviors that are controlled by various parameters that mutate. That is, each organism contains a collection of numbers or other finite parameters. Each parameter controls one or several aspects of an organism in a well-defined way.
These simulations have creatures that learn and grow using neural nets or a close derivative. Emphasis is often, although not always, on learning rather than on natural selection.
Mathematical models of complex systems are of three types: black-box (phenomenological), white-box (mechanistic, based on the first principles ) and grey-box (mixtures of phenomenological and mechanistic models). [ 12 ] [ 13 ] In black-box models, the individual-based (mechanistic) mechanisms of a complex dynamic system remain hidden.
Black-box models are completely nonmechanistic. They are phenomenological and ignore a composition and internal structure of a complex system. Due to the non-transparent nature of the model, interactions of subsystems cannot be investigated. In contrast, a white-box model of a complex dynamic system has ‘transparent walls’ and directly shows underlying mechanisms. All events at the micro-, meso- and macro-levels of a dynamic system are directly visible at all stages of a white-box model's evolution. In most cases, mathematical modelers use the heavy black-box mathematical methods, which cannot produce mechanistic models of complex dynamic systems. Grey-box models are intermediate and combine black-box and white-box approaches.
Creation of a white-box model of complex system is associated with the problem of the necessity of an a priori basic knowledge of the modeling subject. The deterministic logical cellular automata are necessary but not sufficient condition of a white-box model. The second necessary prerequisite of a white-box model is the presence of the physical ontology of the object under study. The white-box modeling represents an automatic hyper-logical inference from the first principles because it is completely based on the deterministic logic and axiomatic theory of the subject. The purpose of the white-box modeling is to derive from the basic axioms a more detailed, more concrete mechanistic knowledge about the dynamics of the object under study. The necessity to formulate an intrinsic axiomatic system of the subject before creating its white-box model distinguishes the cellular automata models of white-box type from cellular automata models based on arbitrary logical rules. If cellular automata rules have not been formulated from the first principles of the subject, then such a model may have a weak relevance to the real problem. [ 13 ]
This is a list of artificial life and digital organism simulators:
Hardware-based artificial life mainly consist of robots , that is, automatically guided machines able to do tasks on their own.
Biochemical-based life is studied in the field of synthetic biology . It involves research such as the creation of synthetic DNA . The term "wet" is an extension of the term " wetware ". Efforts toward "wet" artificial life focus on engineering live minimal cells from living bacteria Mycoplasma laboratorium and in building non-living biochemical cell-like systems from scratch.
In May 2019, researchers reported a new milestone in the creation of a new synthetic (possibly artificial ) form of viable life , a variant of the bacteria Escherichia coli , by reducing the natural number of 64 codons in the bacterial genome to 59 codons instead, in order to encode 20 amino acids . [ 18 ] [ 19 ]
Artificial life has had a controversial history. John Maynard Smith criticized certain artificial life work in 1994 as "fact-free science". [ 23 ] | https://en.wikipedia.org/wiki/List_of_digital_organism_simulators |
This is a list of discontinued music notation programs . For non-discontinued products, see List of scorewriters . | https://en.wikipedia.org/wiki/List_of_discontinued_scorewriters |
This is a list of substances or materials generally considered discredited.
A substance can be discredited in one of three ways:
This is not to be construed as implying that these items– as they are understood today –are discredited. What is listed are fire, water, metal, etc. as universal principles or fundamentals. | https://en.wikipedia.org/wiki/List_of_discredited_substances |
This is a list of notable discrete-event simulation software.
"JaamSim provides everything which is necessary to model typical planning tasks in production and logistics and proves as a real alternative to commercial DES tools." [ 20 ] | https://en.wikipedia.org/wiki/List_of_discrete_event_simulation_software |
Divers face specific physical and health risks when they go underwater with scuba or other diving equipment , or use high pressure breathing gas . Some of these factors also affect people who work in raised pressure environments out of water, for example in caissons . This article lists hazards that a diver may be exposed to during a dive, and possible consequences of these hazards, with some details of the proximate causes of the listed consequences. A listing is also given of precautions that may be taken to reduce vulnerability, either by reducing the risk or mitigating the consequences. A hazard that is understood and acknowledged may present a lower risk if appropriate precautions are taken, and the consequences may be less severe if mitigation procedures are planned and in place.
A hazard is any agent or situation that poses a level of threat to life, health, property, or environment. Most hazards remain dormant or potential, with only a theoretical risk of harm, and when a hazard becomes active, and produces undesirable consequences, it is called an incident and may culminate in an emergency or accident. Hazard and vulnerability interact with likelihood of occurrence to create risk, which can be the probability of a specific undesirable consequence of a specific hazard, or the combined probability of undesirable consequences of all the hazards of a specific activity. The presence of a combination of several hazards simultaneously is common in diving, and the effect is generally increased risk to the diver, particularly where the occurrence of an incident due to one hazard triggers other hazards with a resulting cascade of incidents. Many diving fatalities are the result of a cascade of incidents overwhelming the diver, who should be able to manage any single reasonably foreseeable incident . The assessed risk of a dive would generally be considered unacceptable if the diver is not expected to cope with any single reasonably foreseeable incident with a significant probability of occurrence during that dive. Precisely where the line is drawn depends on circumstances. Commercial diving operations tend to be less tolerant of risk than recreational, particularly technical divers, who are less constrained by occupational health and safety legislation.
Decompression sickness and arterial gas embolism in recreational diving are associated with certain demographic, environmental, and dive style factors. A statistical study published in 2005 tested potential risk factors: age, gender, body mass index, smoking, asthma, diabetes, cardiovascular disease, previous decompression illness, years since certification, dives in last year, number of diving days, number of dives in a repetitive series, last dive depth, nitrox use, and drysuit use. No significant associations with decompression sickness or arterial gas embolism were found for asthma, diabetes, cardiovascular disease, smoking, or body mass index. Increased depth, previous DCI, days diving, and being male were associated with higher risk for decompression sickness and arterial gas embolism. Nitrox and drysuit use, greater frequency of diving in the past year, increasing age, and years since certification were associated with lower risk, possibly as indicators of more extensive training and experience. [ 1 ]
Statistics show diving fatalities comparable to motor vehicle accidents of 16.4 per 100,000 divers and 16 per 100,000 drivers. Divers Alert Network 2014 data shows there are 3.174 million recreational scuba divers in America, of which 2.351 million dive 1 to 7 times per year and 823,000 dive 8 or more times per year. It is reasonable to say that the average would be in the neighbourhood of 5 dives per year. [ 2 ]
Protection in order of effectiveness:
Hazards specific to special purpose underwater tools should be described in the article for the tool, but may be added here. | https://en.wikipedia.org/wiki/List_of_diving_hazards_and_precautions |
The following is a list of dock applications . | https://en.wikipedia.org/wiki/List_of_dock_applications |
Dominance hierarchies occur in many social animals.
Researcher M. W. Foster investigated primates and found that the leaders were more likely to be those who did more for those around them instead of being determined by strength. [ 1 ]
Alpha male baboons monopolize resources and mating access to females, and they are also more likely to suffer from stress. [ 2 ] Lower status males must expend more time and energy for mating opportunities. Alpha males may sometimes allow subordinate males to have access to mating, so the subordinate males can serve as "spare dads" and protect their offspring from other alpha males. [ 3 ]
A study on the association of alpha males and females during the non-breeding season in wild Capuchin monkeys examined whether alpha males are the preferred mate for females and, secondly, whether female-alpha status and relationship to the alpha-male can be explained through the individual characteristics and or social network of the female. [ 4 ] The results indicated that alpha male Capuchin are the preferred mate for adult females. However, only the alpha females had strong interactions with the alpha males by virtue of a dominance hierarchy among the females in which only the most dominant and strong females were able to interact with the alpha male. [ 4 ]
Common chimpanzee males use strength, intelligence, and political alliances to establish and maintain alpha position. [ 5 ] There have been rare cases where a group has killed and even eaten the alpha male. [ 6 ] [ 7 ] Common chimpanzees show deference to the alpha of the community by ritualized postures and gestures such as presenting their back, crouching, bowing, or bobbing. [ 8 ] [ verification needed ] Chimpanzees lower in rank than the alpha male will offer their hand while grunting to the alpha male as a sign of submission. [ 9 ]
Bonobo chimpanzee society on the other hand is governed by alpha females. Males will associate with females for rank acquisition because females dominate the social environment. If a male is to achieve alpha status in a bonobo group, he must be accepted by the alpha female. [ 10 ] Female bonobos will interact sexually to increase social status. High-ranking females rarely interact sexually with other females, but low-ranking females interact sexually with all females. [ 11 ]
Gorillas use intimidation to establish and maintain alpha position. A study conducted regarding the reproductive behavior of male mountain gorillas ( Gorilla beringei beringei ) found further evidence that dominant males are favored to father offspring, even when there is a greater number of males in a notably enlarged group size. The study also concluded that mating access dropped off less steeply with status, so that non-dominant males had mating success more similar to the alpha male than had been expected. [ 12 ]
Adult male mandrills with alpha status display vivid coloration on their skin, while those with beta status are more dull in colour. Both types of males engage in mating, but only the dominant alpha males have the ability to produce offspring. Male mandrills sometimes fight for breeding rights which results in dominance. Though conflicts are rare, they can be deadly. Gaining dominance, that is becoming the alpha male, results in an "increased testicular volume, reddening of sexual skin on the face and genitalia, and heightened secretion of the sternal cutaneous gland". [ 13 ] When a male loses dominance or its alpha status, the reverse happens, although the blue ridges remain brightened. There is also a fall in its reproductive success. This effect is gradual and takes place over a few years. [ 14 ] [ 15 ] [ 16 ] When beta males mate-guard a female, the competition between them allows the alpha males to have a greater chance of producing offspring, [ 17 ] since betas outnumber alphas 21 to 1.
Dominant male elephant seals arrive at potential breeding sites in spring, and fast to ensure that they can mate with as many females as possible. [ 18 ] Male elephant seals use fighting, vocal noises, and different positions to determine who will be deemed the dominant male. [ 18 ] [ 19 ] When males reach eight to nine years of age, they have developed a pronounced long nose, in addition to a chest shield, which is thickened skin in their chest area. [ 18 ] They display their dominance by showing their noses, making loud vocalisations, and altering their postures. [ 18 ] [ 19 ] They fight each other by raising themselves and ramming each other with their chests and teeth. [ 18 ]
When females arrive, the dominating males have already selected their territory on the beach. [ 18 ] Females cluster in groups called harems, which could consist of up to 50 females surrounding one alpha male. [ 18 ] Outside of these groups, a beta bull is normally roaming around on the beach. [ 18 ] The beta bull helps the alpha by preventing other males accessing the females. [ 18 ] In return, the beta bull might have an opportunity to mate with one of the females while the alpha is occupied. [ 18 ]
In the past, the prevailing view on gray wolf packs was that they consisted of individuals vying with each other for dominance, with dominant gray wolves being referred to as the "alpha" male and female, and the subordinates as "beta" and "omega" wolves. This terminology was first used in 1947 by Rudolf Schenkel of the University of Basel , who based his findings on researching the behavior of captive gray wolves. [ 20 ] This view on gray wolf pack dynamics was later popularized by the researcher L. David Mech in his 1970 book The Wolf . He later found additional evidence that the concept of an Alpha male may have been an interpretation of incomplete data and formally disavowed this terminology in 1999. He explained that it was heavily based on the behavior of captive packs consisting of unrelated individuals, an error reflecting the once prevailing view that wild pack formation occurred in winter among independent gray wolves. Later research on wild gray wolves revealed that the pack is usually a family consisting of a breeding pair and their offspring of the previous 1–3 years. In the article, Mech wrote that the use of the term "alpha" to describe the breeding pair adds no additional information, and is "no more appropriate than referring to a human parent or a doe deer as an alpha." He further notes the terminology falsely implies a "force-based dominance hierarchy." In 13 years of summer observations of wild wolves, he witnessed no dominance contests between them. [ 21 ]
In some other wild canids, the alpha male may not have exclusive access to the alpha female. [ 22 ] Other pack members as in the African wild dog ( Lycaon pictus ) may guard the maternity den used by the alpha female. [ 23 ]
Male Chiroxiphia manakins can typically be designated alpha and beta, since there is a clear dominance relationship between them. There is only ever one alpha male, but, depending on species, there may be one or two beta males. Beta males are sometimes sub-adults - easily recognized, as their plumage retain female-like characters. Only the alpha male is ever seen to mate with the female. [ 24 ]
Webster et al. observed that males defend sexually-receptive females, suggesting that Montezuma oropendolas have a female-defence mating system . While the females nest, the males fight and fend off one another, and the males were ranked depending on the outcome of each fight. The alpha male eventually pushes out all other males until he is the only one left. When the alpha males leave the others come back and defend females until he returns. This type of mating system is similar to that of polygynous mammals, not birds. [ 25 ]
Normally, female pale chanting goshawks mate with a single male ( monogamy ), but in "broken veld " vegetation (a prey-rich habitat in the Little Karoo ), a female and two males may form a polyandrous trio. [ 26 ] In these cases an alpha male and female will be assisted in raising the young by a beta male. The alpha male copulates with the female 31-5 days before laying while the beta male copulates 5-3 days before laying. [ 27 ] Subordinate co-breeding males may have reproductive fitness benefits by assisting the alpha female with nest defense and prey provision. [ 28 ] Non-breeding individuals from previous broods may remain in their natal territory and form part of the breeding group. [ 26 ]
Aggressive behavior in cichlids is ritualized and consists of multiple displays used to seek confrontation while being involved in evaluation of competitors, [ 29 ] coinciding with temporal proximity to mating. Displays of ritualized aggression in cichlids include a remarkably rapid change in coloration, during which a successfully dominant [ 29 ] territorial male assumes a more vivid and brighter coloration, while a subordinate or "nonterritorial" male assumes a dull-pale coloration. [ 30 ] In addition to color displays, cichlids employ their lateral lines to sense movements of water around their opponents to evaluate the competing male for physical traits/fitness. [ 31 ] Male cichlids are very territorial due to the pressure of reproduction, and establish their territory and social status by physically driving out [ 32 ] challenging males (novel intruders) [ 33 ] through lateral displays (parallel orientation, uncovering gills), [ 34 ] biting, or mouth fights (head-on collisions of open mouths, measuring jaw sizes, and biting each other's jaws). The cichlid social dichotomy is composed of a single dominant with multiple subordinates, where the physical aggression of males becomes a contest for resources [ 32 ] (mates, territory, food). Female cichlids prefer to mate with a successfully alpha male with vivid coloration, whose territory has food readily available.
Some moon wrasses live in groups consisted of a dominant male, and a "harem" of about a dozen other wrasses, some female and some male. [ 35 ] The alpha male is more brightly colored, and at every low tide hour, changes from green to blue, and goes into a show of attacking and nipping all the other wrasses. This is his way of showing his dominance to the rest of the males and keeping the females in check. During breeding season and before high tide, the alpha male turns completely blue, gathers up every single female, and the spawning frenzy begins.
Mozambique tilapias often travel in groups where a strict dominance hierarchy is maintained. Positions within the hierarchy correlate with territoriality, courtship rate, nest size, aggression, and hormone production. [ 36 ] In terms of social structure, Mozambique tilapias engage in a system known as lek-breeding , where males establish territories with dominance hierarchies while females travel between them. Social hierarchies typically develop because of competition for limited resources including food, territories, or mates. During the breeding season, males cluster around certain territory, forming a dense aggregation in shallow water. [ 37 ] This aggregation forms the basis of the lek through which the females preferentially choose their mates. Reproductive success by males within the lek is highly correlated to social status and dominance. [ 38 ]
In experiments with captive tilapias, evidence demonstrates the formation of linear hierarchies where the alpha male participates in significantly more agonistic interactions. Thus, males that are higher ranked initiate much more aggressive acts than subordinate males. However, contrary to popular belief, Mozambique tilapias display more agonistic interactions towards fish that are farther apart in the hierarchy scale than they do towards individuals closer in rank. One hypothesis behind this action rests with the fact that aggressive actions are costly. In this context, members of this social system tend to avoid confrontations with neighboring ranks in order to conserve resources rather than engage in an unclear and risky fight. Instead, dominant individuals seek to bully subordinate tilapias both for an easy fight and to keep their rank. [ 39 ]
The American pika ( Ochotona princeps ) is known to maintain strict territorial boundaries, and dominance between individuals is enforced through a dominant pika invading another pika's territory, forcing the latter out. The general hierarchy of dominance has been observed (higher to lower in dominance) from male to female and adult to juvenile. Pikas with greater body mass were perceived as more dominant. [ 40 ]
Both domestic rabbits ( Oryctolagus cuniculus ) and wild rabbits, such as the swamp rabbit ( Sylvilagus aquaticus ), maintain dominance hierarchies in control of territory and frequency of copulation. [ 41 ] Social strata within groups of female domestic rabbits have been observed. [ 42 ] | https://en.wikipedia.org/wiki/List_of_dominance_hierarchy_species |
This is a list of dopaminergic drugs . These are pharmaceutical drugs , naturally occurring compounds and other chemicals that influence the function of the neurotransmitter dopamine .
Dopamine receptors are a class of G protein-coupled receptors that are prominent in the vertebrate central nervous system (CNS) and are implicated in many neurological processes, including motivational and incentive salience, cognition, memory, learning, and fine motor control, as well as modulation of neuroendocrine signaling. Abnormal dopamine receptor signaling and dopaminergic nerve function is implicated in several neuropsychiatric disorders. [ 1 ] Dopamine receptors are therefore common drug targets.
Dopamine receptors activate different effectors through not only G-protein coupling, but also signaling through different protein (dopamine receptor-interacting proteins) interactions. [ 2 ]
Adamantanes : Amantadine • Memantine • Rimantadine
Aminotetralins : 7-OH-DPAT • 8-OH-PBZI • Rotigotine • UH-232
Benzazepines : 6-Br-APB • Fenoldopam • SKF-38,393 • SKF-77,434 • SKF-81,297 • SKF-82,958 • SKF-83,959
Ergolines : Bromocriptine • Cabergoline • Dihydroergocryptine • Lisuride • Lysergic acid diethylamide (LSD) • Pergolide
Dihydrexidine derivatives : 2-OH-NPA • A-86,929 • Ciladopa • Dihydrexidine • Dinapsoline • Dinoxyline • Doxanthrine
Others : A-68,930 • A-77,636 • A-412,997 • ABT-670 • ABT-724 • Aplindore • Apomorphine • Aripiprazole • Azodopa • Bifeprunox • BP-897 • CY-208,243 • Dizocilpine • Etilevodopa • Flibanserin • Ketamine • Melevodopa • Modafinil • Pardoprunox • Phencyclidine • PD-128,907 • PD-168,077 • PF-219,061 • Piribedil • Pramipexole • Propylnorapomorphine • Pukateine • Quinagolide • Quinelorane • Quinpirole • RDS-127 • Ro10-5824 • Ropinirole • Rotigotine • Roxindole • Salvinorin A • SKF-89,145 • Sumanirole • Terguride • Umespirone • WAY-100,635
Typical antipsychotics : Acepromazine • Azaperone • Benperidol • Bromperidol • Clopenthixol • Chlorpromazine • Chlorprothixene • Droperidol • Flupentixol • Fluphenazine • Fluspirilene • Haloperidol • Loxapine • Mesoridazine • Methotrimeprazine • Nemonapride • Penfluridol • Perazine • Periciazine • Perphenazine • Pimozide • Prochlorperazine • Promazine • Sulforidazine • Sulpiride • Sultopride • Thioridazine • Thiothixene • Trifluoperazine • Triflupromazine • Trifluperidol • Zuclopenthixol
Atypical antipsychotics : Amisulpride • Asenapine • Blonanserin • Cariprazine • Carpipramine • Clocapramine • Clozapine • Gevotroline • Iloperidone • Lurasidone • Melperone • Molindone • Mosapramine • Ocaperidone • Olanzapine • Paliperidone • Perospirone • Piquindone • Quetiapine • Remoxipride • Risperidone • Sertindole • Tiospirone • Ziprasidone • Zotepine
Antiemetics : AS-8112 • Alizapride • Bromopride • Clebopride • Domperidone • Metoclopramide • Thiethylperazine
Others : Amoxapine • Buspirone • Butaclamol • Ecopipam • N-Ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) • Eticlopride • Fananserin • L-745,870 • Nafadotride • Nuciferine • PNU-99,194 • Raclopride • Sarizotan • SB-277,011-A • SCH-23,390 • SKF-83,566 • SKF-83,959 • Sonepiprazole • Spiperone • Spiroxatrine • Stepholidine • Tetrahydropalmatine • Tiapride • UH-232 • Yohimbine
Piperazines : DBL-583 • GBR-12,935 • Nefazodone • Vanoxerine
Piperidines : 1-(1-(1-Benzothiophen-2-yl)cyclohexyl)piperidine (BTCP) • Desoxypipradrol • Dextromethylphenidate • Difemetorex • Ethylphenidate • Methylnaphthidate • Isopropylphenidate • Methylphenidate • Phencyclidine • Pipradrol
Pyrrolidines : Diphenylprolinol • Methylenedioxypyrovalerone (MDPV) • Naphyrone • Prolintane • Pyrovalerone
Tropanes : 3β-(4'-Chlorophenyl)-2β-(3'-phenylisoxazol-5'-yl)tropane (β-CPPIT) • Altropane • Brasofensine • WIN 35428 (β-CFT) • Cocaine • Dichloropane • Difluoropine • N-(2'-Fluoroethyl-)-3β-(4'-chlorophenyl)-2β-(3'-phenylisoxazol-5'-yl)nortropane (FE-β-CPPIT) • N-(3'-Fluoropropyl-)-3β-(4'-chlorophenyl)-2β-(3'-phenylisoxazol-5'-yl)nortropane (FP-β-CPPIT) • Ioflupane ( 123 I) • Iometopane • RTI-112 • RTI-113 • RTI-121 • RTI-126 • RTI-150 • RTI-177 • RTI-229 • RTI-336 • Tenocyclidine • Tesofensine • Troparil • Tropoxane • 2β-Propanoyl-3β-(4-tolyl)-tropane (WF-11) • 2β-Propanoyl-3β-(2-naphthyl)-tropane (WF-23) • 2-Propanoyl-3-(4-isopropylphenyl)-tropane (WF-31) • 2α-(Propanoyl)-3β-(2-(6-methoxynaphthyl))-tropane (WF-33)
Others : Adrafinil • Armodafinil • Amfonelic acid • Amineptine • Benzatropine (benztropine) • Bromantane • 2-Butyl-3-(p-tolyl)quinuclidine (BTQ) • BTS-74,398 • Bupropion (amfebutamone) • Ciclazindol • Diclofensine • Dimethocaine • Diphenylpyraline • Dizocilpine • DOV-102,677 • DOV-21,947 • DOV-216,303 • Etybenzatropine (ethylbenztropine) • EXP-561 • Fencamine • Fencamfamine • Fezolamine • GYKI-52,895 • Hydrafinil • Indatraline • Ketamine • Lefetamine • Levophacetoperane • LR-5182 • Manifaxine • Mazindol • Medifoxamine • Mesocarb • Modafinil • Nefopam • Nomifensine • NS-2359 • O-2172 • Pridefrine • Propylamphetamine • Radafaxine • SEP-225,289 • SEP-227,162 • Sertraline • Sibutramine • Tametraline • Tripelennamine
Deserpidine • Deutetrabenazine • Ibogaine • Reserpine • Tetrabenazine • Valbenazine
Morpholines : Fenbutrazate • Morazone • Phendimetrazine • Phenmetrazine
Oxazolines : 4-Methylaminorex (4-MAR, 4-MAX) • Aminorex • Clominorex • Cyclazodone • Fenozolone • Fluminorex • Pemoline • Thozalinone
Phenethylamines (also amphetamines , cathinones , phentermines , etc.): 2-Hydroxyphenethylamine (2-OH-PEA) • 4-Chlorophenylisobutylamine (4-CAB) • 4-Methylamphetamine (4-MA) • 4-Methylmethamphetamine (4-MMA) • Alfetamine • Amfecloral • Amfepentorex • Amfepramone • Amphetamine ( dextroamphetamine , levoamphetamine ) • Amphetaminil • β-Methylphenethylamine (β-Me-PEA) • Benzodioxolylbutanamine (BDB) • Benzodioxolylhydroxybutanamine (BOH) • Benzphetamine • Buphedrone • Butylone • Cathine • Cathinone • Clobenzorex • Clortermine • D-Deprenyl • Dimethoxyamphetamine (DMA) • Dimethoxymethamphetamine (DMMA) • Dimethylamphetamine • Dimethylcathinone (dimethylpropion, metamfepramone) • Ethcathinone (ethylpropion) • Ethylamphetamine • Ethylbenzodioxolylbutanamine (EBDB) • Ethylone • Famprofazone • Fenethylline • Fenproporex • Flephedrone • Fludorex • Furfenorex • Hordenine • Lophophine (homomyristicylamine) • Mefenorex • Mephedrone • Methamphetamine (desoxyephedrine, methedrine; dextromethamphetamine , levomethamphetamine ) • Methcathinone (methylpropion) • Methedrone • Methoxymethylenedioxyamphetamine (MMDA) • Methoxymethylenedioxymethamphetamine (MMDMA) • Methylbenzodioxolylbutanamine (MBDB) • Methylenedioxyamphetamine (MDA, tenamfetamine) • Methylenedioxyethylamphetamine (MDEA) • Methylenedioxyhydroxyamphetamine (MDOH) • Methylenedioxymethamphetamine (MDMA) • Methylenedioxymethylphenethylamine (MDMPEA, homarylamine) • Methylenedioxyphenethylamine (MDPEA, homopiperonylamine) • Methylone • Ortetamine • Parabromoamphetamine (PBA) • Parachloroamphetamine (PCA) • Parafluoroamphetamine (PFA) • Parafluoromethamphetamine (PFMA) • Parahydroxyamphetamine (PHA) • Paraiodoamphetamine (PIA) • Paredrine (norpholedrine, oxamphetamine) • Phenethylamine (PEA) • Pholedrine • Phenpromethamine • Prenylamine • Propylamphetamine • Tiflorex (flutiorex) • Tyramine (TRA) • Xylopropamine • Zylofuramine
Piperazines : 2,5-Dimethoxy-4-bromobenzylpiperazine (2C-B-BZP) • Benzylpiperazine (BZP) • Methoxyphenylpiperazine (MeOPP, paraperazine) • Methylbenzylpiperazine (MBZP) • Methylenedioxybenzylpiperazine (MDBZP, piperonylpiperazine)
Others : 2-Amino-1,2-dihydronaphthalene (2-ADN) • 2-Aminoindane (2-AI) • 2-Aminotetralin (2-AT) • 4-Benzylpiperidine (4-BP) • 5-Iodo-2-aminoindane (5-IAI) • Clofenciclan • Cyclopentamine • Cypenamine • Cyprodenate • Feprosidnine • Gilutensin • Heptaminol • Hexacyclonate • Indanylaminopropane (IAP) • Indanorex • Isometheptene • Methylhexanamine • Naphthylaminopropane (NAP) • Octodrine • Phthalimidopropiophenone • Propylhexedrine ( levopropylhexedrine ) • Tuaminoheptane (tuamine)
Benzofuranylpropylaminopentane (BPAP) • Desmethylselegiline • Indolylpropylaminopentane (IPAP) • Phenethylamine • Phenylpropylaminopentane (PPAP) • Selegiline (L-deprenyl) • Tryptamine • Tyramine
3,4-Dihydroxystyrene
3-Iodotyrosine • Aquayamycin • Bulbocapnine • Metirosine • Oudenone
Benserazide • Carbidopa • Genistein • Methyldopa
Nonselective : Benmoxin • Caroxazone • Echinopsidine • Furazolidone • Hydralazine • Indantadol • Iproclozide • Iproniazid • Isocarboxazid • Isoniazid • Linezolid • Mebanazine • Metfendrazine • Nialamide • Octamoxin • Paraxazone • Phenelzine • Pheniprazine • Phenoxypropazine • Pivalylbenzhydrazine • Procarbazine • Safrazine • Tranylcypromine
MAO-A selective : Amiflamine • Bazinaprine • Befloxatone • Befol • Brofaromine • Cimoxatone • Clorgiline • Esuprone • Harmala alkaloids ( harmine , harmaline , tetrahydroharmine , harman , norharman , etc.) • Methylene blue • Metralindole • Minaprine • Moclobemide • Pirlindole • Sercloremine • Tetrindole • Toloxatone • Tyrima
MAO-B selective : D-Deprenyl • Selegiline (L-deprenyl) • Ladostigil • Lazabemide • Milacemide • Mofegiline • Pargyline • Rasagiline • Safinamide
Entacapone • Nitecapone • Opicapone • Tolcapone
Bupicomide • Disulfiram • Dopastin • Fusaric acid • Nepicastat • Phenopicolinic acid • Tropolone
L-Phenylalanine → L-tyrosine → L-DOPA (levodopa)
Ferrous iron (Fe 2+ ) • Tetrahydrobiopterin • Vitamin B 3 ( niacin , nicotinamide → NADPH ) • Vitamin B 6 ( pyridoxine , pyridoxamine , pyridoxal → pyridoxal phosphate ) • Vitamin B 9 ( folic acid → tetrahydrofolic acid ) • Vitamin C ( ascorbic acid ) • Zinc (Zn 2+ )
MPP + • MPTP • Oxidopamine (6-hydroxydopamine)
Etilevodopa • Foslevodopa • Melevodopa • XP-21279
A photoswitchable agonist of D 1 -like receptors ( azodopa ) has been described that allows reversible control of dopaminergic transmission in wildtype animals. | https://en.wikipedia.org/wiki/List_of_dopaminergic_drugs |
The following is an incomplete list of sportspeople who have been involved in doping offences. It contains those who have been found to have, or have admitted to having, taken illegal performance-enhancing drugs , prohibited recreational drugs or have been suspended by a sports governing body for failure to submit to mandatory drug testing . | https://en.wikipedia.org/wiki/List_of_doping_cases_in_sport |
The International Standard for the Prohibited List is the standard published by the World Anti-Doping Agency (WADA) that lists substances prohibited in competitive sport. [ 1 ] [ 2 ] It is updated at least once per year as required by the World Anti-Doping Code. [ 3 ] [ 4 ] The adoption of the first World Anti-Doping Code (the Code) occurred at the 2nd World Conference on Doping in Sport in March 2003 in Copenhagen, Denmark. It was there that WADA assumed the responsibility of maintaining, updating, and publishing the List of Prohibited Substances and Methods (the List) in sport. The List is to be updated and published by WADA at least annually. [ 5 ] WADA specifies that the List generally includes any substance that meets any two of the following criteria: it enhances sport performance, it represents a health risk to the athlete, it violates the spirit of sport (as defined in the WADA Code). [ 3 ]
Substances and techniques that are prohibited by WADA fall into the following categories: [ 2 ] S0 non-approved substances;
S1 anabolic agents;
S2 peptide hormones, growth factors, related substances, and mimetics ;
S3 beta-2 agonists;
S4 hormone and metabolic modulators;
S5 diuretics and masking agents;
prohibited methods (M1 blood doping , M2 manipulation of samples, M3 gene doping );
S6 stimulants;
S7 narcotics;
S8 cannabinoids;
S9 glucocorticoids;
P1 beta-blockers.
Blood doping is the injection of red blood cells , related blood products that contain red blood cells, or artificial oxygen containers. This is done by extracting and storing one's own blood prior to an athletic competition, well in advance of the competition so that the body can replenish its natural levels of red blood cells, and subsequently injecting the stored blood immediately before competition. The resulting unnatural level of red blood cells improves oxygen transport and athletic endurance; thus, it is prohibited in most events. It is often used in extreme sports like cycling , snowboarding , and skiing where endurance is highly valued. The most famous example of this type of doping is Lance Armstrong 's performance in the Tour de France . [ 6 ]
Banned anabolic agents are, for the purpose of WADA, either anabolic steroids , which activate testosterone and epitestosterone receptors, thereby improving muscle strength and endurance, or "other anabolic agents". Andro, DHEA, stanozolol , testosterone , and nandrolone , or derivates (see below) are banned anabolic steroids. Other banned anabolic agents include clenbuterol , tibolone , zeranol , zilpaterol , and selective androgen receptor modulators . [ 7 ] While a few of the banned drugs are endogenous, that is they are normally produced in the human body, most of the banned drug are exogenous drugs chemically produced. These types of drugs were used extensively in Major League Baseball in the 1990s and early 2000s . [ 8 ]
This is the complete list of exogenous (non-natural) androgenic agents banned as of January 1, 2012:
Drugs with similar structures and biological activity are also banned because new designer drugs of this sort are always being developed in order to beat the drug tests .
Caffeine , a stimulant known to improve performance, is currently not on the banned list. It was listed until 2004, with a maximum allowed level of 12 micrograms per millilitre urine. [ 9 ]
The following substances, ordinarily produced naturally in the body, are prohibited when administered from outside the body.
Metabolites and isomers of endogenous anabolic androgenic steroids, including:
Certain peptide hormones increase bulk, strength, and oxygen-carrying red blood cells. [ 7 ] : 3
Erythropoiesis-stimulating agents such as erythropoietin (EPO), darbepoetin (dEPO), hypoxia-inducible factor (HIF) stabilizers, methoxy polyethylene glycol-epoetin beta (CERA) and peginesatide (Hematide); growth hormone (hGH), insulin-like growth factors ( IGF-1 , etc.), fibroblast growth factors (FGFs), hepatocyte growth factors (HGF), mechano growth factors (MGFs), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), human chorionic gonadotropin (hcG, banned in men only), somatotrophin (growth hormone), insulins and corticotrophins , corticosteroid mimics, and their releasing factor, are banned.
Also banned are any other growth factor affecting muscle, tendon or ligament protein synthesis/degradation, vascularization, energy utilization, regenerative capacity or fiber type switching, and other substances with similar chemical structure and/or biological effects.
All beta-2 agonists and their D - and L - isomers , are banned. However, formoterol , salbutamol , salmeterol , and terbutaline may be used with a "therapeutic use exemption", only in the inhaled form. [ 7 ] : 4
Hormone levels of a particular hormone, like testosterone, can be changed not only by administering it, but also by altering related hormones. For example, the estrogens estrone and estradiol are biosynthetically produced by the enzyme aromatase , respectively, from androstenedione and testosterone, which are both produced from 17α-hydroxyprogesterone . Thus, when the body senses low levels of estrogen, the precursor compounds 17α-hydroxyprogesterone, androstenedione, and testosterone are up-regulated. Likewise, interfering with a hormone's receptor leads to similar effects.
Because of these natural hormone-hormone interdependent biosynthetic pathways and hormone-receptor interactions, all aromatase inhibitors , including anastrozole , letrozole , aminoglutethimide , exemestane , formestane , and testolactone are banned. Selective estrogen receptor modulators , including raloxifene , tamoxifen and toremifene are banned. Clomiphene , cyclofenil , fulvestrant , and all other anti-estrogenic substances are banned. Myostatin inhibitors are banned. Metabolic modulators including peroxisome proliferator-activated receptor delta (PPARδ) agonists (e.g., GW 1516 ), PPARδ- AMP-activated protein kinase (AMPK) axis agonists (e.g. AICAR ) are also banned. Meldonium was banned on 1 January 2016, which was often used during the Russian doping scandal . [ 7 ] : 4
Diuretics , which increase the production of urine , and masking agents, chemical compounds which interfere with drug tests, are banned for two reasons. First, by decreasing water retention and thus decreasing an athlete's weight, an important consideration in many speed sports (e.g. track and field , speed skating ), they increase the speed of an athlete. Secondly, increased urine production depletes the concentration of both the banned drugs and their metabolites, making their detection more difficult. Masking agents, on the other hand, work by making drug tests ineffective, leading to false-negative results. Desmopressin , plasma expanders (such as glycerol ; intravenous administration of albumin , dextran , hydroxyethyl starch and mannitol ), probenecid , and other substances with similar biological effects are also banned. Local application of felypressin in dental anesthesia is not prohibited. [ 7 ] : 5
The following diuretics, and chemicals with similar structure or biological activity are banned:
Stimulants directly affect the central nervous system, increasing blood flow and heart rate. These drugs primarily help athletes in complex team sports like basketball and association football as well as choreographed sports like figure skating and artistic gymnastics . Stimulants that are banned in competition only include amphetamines , beta-2 agonists , ephedrine , pseudoephedrine , fencamfamine , cocaine , methamphetamines , mesocarb , and other substances with similar chemical structures and biological effects, including the following: [ 7 ] : 6
Narcotic analgesics decrease the painful sensations of serious injuries, potentially allowing athletes to continue training for competition after an injury. While some painkillers are allowed, including codeine , the following are banned in competition only : [ 7 ] : 7
The following are banned for in-competition use only, with the exception of cannabidiol (CBD) which is not banned for any use. [ 2 ] In 2013, the level of THC metabolite allowed was changed from 15 ng/mL to 150 ng/mL so as to only detect in-competition use. [ 11 ] [ 7 ] : 7
Glucocorticoids are a class of corticosteroids that affect the metabolism of carbohydrates , fat , and proteins , and regulate glycogen and blood pressure levels. They possess pronounced anti-inflammatory activity and cause alteration of connective tissue in response to injuries. The anti-inflammatory and connective tissue effects of glucocorticoids might mask injuries, leading to more serious injuries to athletes. Because of this and metabolic regulation effects, the administration of any glucocorticoid orally, rectally, intravenously, or intramuscularly is prohibited in competition only and requires a therapeutic use exemption. Topical uses of glucocorticoids does not require an exemption. [ 7 ] : 7
Beta blockers are prohibited during competition in a number of sports; out of competition, they are prohibited only in archery and shooting . The prohibited beta blockers include: [ 7 ] : 8
Therapeutic use exemption (TUE) is a term used by WADA and the United States Anti-Doping Agency to denote banned substances that athletes may be "required to take to treat an illness or condition". [ 12 ] [ 13 ] These exemptions are regulated by the International Standard for Therapeutic Use Exemptions (ISTUE). The detection of such substances in samples is labelled by WADA as an "adverse analytical finding" (AAF), which is distinct from "anti-doping rules violations" (ADRV). [ 14 ]
Prohibited methods include manipulation of blood components (e.g. autologous red blood cell transfer, "blood doping"), manipulation of samples, and gene doping . These are prohibited at all times. [ 7 ] : 5 | https://en.wikipedia.org/wiki/List_of_drugs_banned_by_the_World_Anti-Doping_Agency |
The following is a table of drugs organized by their year of discovery.
Naturally occurring chemicals in plants, including alkaloids , have been used since pre-history. In the modern era, plant-based drugs have been isolated, purified and synthesised anew. Synthesis of drugs has led to novel drugs, including those that have not existed before in nature, particularly drugs based on known drugs which have been modified by chemical or biological processes.
Archaeological evidence indicates that the use of medicinal plants dates back to the Paleolithic age. [ citation needed ]
In ancient Egypt, herbs are mentioned in Egyptian medical papyri , depicted in tomb illustrations, or on rare occasions found in medical jars containing trace amounts of herbs. [ 1 ] Medical recipes from 4000 BCE were for liquid preparations rather than solids. [ 2 ] In the 4th millennium BCE, Soma (drink) and Haoma are named, but is not clear what ingredients were used to prepare them. [ citation needed ]
Written around 1600 BCE, the Edwin Smith Papyrus describes the use of many herbal drugs. The Ebers Papyrus – one of the most important medical papyri of ancient Egypt – was written around 1550 BCE, and covers more than 700 drugs, mainly of plant origin. [ 7 ] The first references to pills were found on papyri in ancient Egypt, and contained bread dough, honey, or grease. Medicinal ingredients such as plant powders or spices were mixed in and formed by hand to make little balls, or pills. [ 2 ] The papyri also describe how to prepare herbal teas , poultices , ointments , eye drops , suppositories , enemas , laxatives , etc. Aloe vera was used in the 2nd millennium BCE. [ 8 ]
In Greece , Theophrastus of Eresos wrote Historia Plantarum in the 4th century BCE . [ 9 ] Seeds likely used for herbalism have been found in archaeological sites of Bronze Age China dating from the Shang dynasty [ 10 ] (c. 1600 BCE–c. 1046 BCE). Over a hundred of the 224 drugs mentioned in the Huangdi Neijing – an early Chinese medical text – are herbs. [ 11 ] Herbs also commonly featured in the medicine of ancient India, where the principal treatment for diseases was diet. [ 12 ]
Opioids are among the world's oldest known drugs. [ 13 ] [ 14 ] Use of the opium poppy for medical, recreational, and religious purposes can be traced to the 4th century BCE, when Hippocrates wrote about it for its analgesic properties, stating, "Divinum opus est sedare dolores." (" Divine work is the easing of pain ") [ 15 ]
In ancient Greece, pills were known as katapotia ("something to be swallowed"). Pliny the Elder , who lived from 23–79 CE, first gave a name to what we now call pills, calling them pilula . [ 2 ] Pliny also wrote Naturalis Historia a collection of 38 books and the first pharmacopoea .
Pedanius Dioscorides wrote De Materia Medica (c. 40 – 90 CE); this book dominated the area of drug knowledge for some 1500 years until the 1600s. [ 18 ]
Jojoba was used in the 1st millennium CE.
Aelius Galenus wrote more than 11 books about drugs , also use terra sigillata with kaolinite and goats blood to produce tablets.
Drugs developed in the post-classical (circa 500 to 1450) or early modern eras (circa 1453 to 1789).
In middle age ointments were a common dosage form .
Beta carboline ( GABA A receptor inverse agonist) [ citation needed ]
Avicenna separates Medicine and Pharmacy , in 1025 published his book The Canon of Medicine , an encyclopedia of medicine formed by five books. Drugs mentioned by Avicenna include agaric , scammony and euphorbium . [ 19 ] The latex of Euphorbia resinifera contains resiniferatoxin , an ultra potent capsaicin analog. Desensitization to resiniferatoxin is tested in clinical trials to treat neuropathic pain. [ 20 ]
(In general, a powerful purgative and anthelmintic ) [ citation needed ]
Paracelsus expounded the concept of dose response in his Third Defense, where he stated that "Solely the dose determines that a thing is not a poison." This was used to defend his use of inorganic substances in medicine as outsiders frequently criticized Paracelsus' chemical agents as too toxic to be used as therapeutic agents. Paracelsus discovered that the alkaloids in opium are far more soluble in alcohol than water. Having experimented with various opium concoctions, Paracelsus came across a specific tincture of opium that was of considerable use in reducing pain. He called this preparation laudanum . [ citation needed ]
For over a thousand years South American indigenous peoples have chewed Erythroxylon coca leaves, which contain alkaloids such as cocaine. Coca leaf remains have been found with ancient Peruvian mummies. [ 21 ] There is also evidence coca leaves were used as an anesthetic. [ 22 ] In 1569, Spanish botanist Nicolás Monardes described the indigenous peoples' practice of chewing a mixture of tobacco and coca leaves to induce "great contentment". [ citation needed ]
1400s Nicotine (Tobacco) [ citation needed ]
In 1778 John Mudge created the first inhaler devices. [ citation needed ] In 1747, James Lind , surgeon of HMS Salisbury , conducted the first clinical trial ever recorded, on it he studied how citrus fruit were capable of curing scurvy . [ citation needed ]
In the 1830s chemist Justus von Liebig began the synthesis of organic molecules, stating that "The production of all organic substances no longer belongs just to living organisms." In 1832 produced chloral hydrate , the first synthetic sleeping drug. In 1833 French chemist Anselme Payen was the first to discover an enzyme , diastase . In 1834, François Mothes and Joseph Dublanc created a method to produce a single-piece gelatin capsule that was sealed with a drop of gelatin solution. In 1853 Alexander Wood was the first physician that used hypodermic needle to dispense drugs via Injections . In 1858 Dr. M. Sales Giron invented the first pressurized inhaler .
Amphetamine was first synthesized in 1887 in Germany by Romanian chemist Lazăr Edeleanu who named it phenylisopropylamine ; [ 23 ] [ 24 ] [ 25 ] its stimulant effects remained unknown until 1927, when it was independently resynthesized by Gordon Alles and reported to have sympathomimetic properties. [ 25 ] Shortly after amphetamine, methamphetamine was synthesized from ephedrine in 1893 by Japanese chemist Nagai Nagayoshi . [ 26 ] Three decades later, in 1919, methamphetamine hydrochloride was synthesized by pharmacologist Akira Ogata via reduction of ephedrine using red phosphorus and iodine . [ 27 ]
In 1901 Jōkichi Takamine isolated and synthesized the first hormone , Adrenaline . In 1907 Alfred Bertheim synthesized Arsphenamine , the first man-made antibiotic. In 1927 Erik Rotheim patented the first aerosol spray can. In 1933 Robert Pauli Scherer created a method to develop softgels .
William Roberts studies about penicillin were continued by Alexander Fleming , who in 1928 concluded that penicillin had an antibiotic effect. In 1944 Howard Florey and Ernst Boris Chain mass-produced penicillin. In 1948 Raymond P. Ahlquist published his seminal work where he divided adrenoceptors into α- and β-adrenoceptor subtypes, this allowed a better understanding of drugs mechanisms of action .
In 1987, after Montreal Protocol , CFC inhalers were phased out and HFA inhalers replace them. In 1987 CRISPR technique was discovered by Yoshizumi Ishino that in the next century would be used for genome editing .
21st century begins with the first complete sequences of individual human genomes by Human Genome Project , on 12 February 2001, this allowed a switch in drug development and research from the traditional way of drug discovery that was isolating molecules from plants or animals or create new molecules and see if they could be useful in treatment of illness in humans, to pharmacogenomics , that is the study and knowledge of how genes respond to drugs. Another field beneficed by Human Genome Project is pharmacogenetics , that is the study of inherited genetic differences in drug metabolic pathways which can affect individual responses to drugs, both in terms of therapeutic effect as well as adverse effects. [ 30 ]
Humane genome study also allowed to identify which genes are responsible of illness, and to develop drugs for rare diseases and also treatment of illness through gene therapy . In 2015 a simplified form of CRISPR edition was used in humans with Cas9 , and also was used an even more simple method, Cas12a that prevent genetic damage from viruses. These advances are improving personalized medicine and allowing precision medicine .
* MA = Monoclonal antibody
SM = Small molecule
ACT = Adoptive cell transfer | https://en.wikipedia.org/wiki/List_of_drugs_by_year_of_discovery |
Pharmaceutical drugs become known for off-label use when publications begin discussing how they can be used for off-label treatment of medical conditions . | https://en.wikipedia.org/wiki/List_of_drugs_known_for_off-label_use |
In mathematics , a duality , generally speaking, translates concepts, theorems or mathematical structures into other concepts, theorems or structures, in a one-to-one fashion, often (but not always) by means of an involution operation: if the dual of A is B , then the dual of B is A . | https://en.wikipedia.org/wiki/List_of_dualities |
This is a list of dyes with Colour Index International generic names and numbers and CAS Registry numbers .
Note | https://en.wikipedia.org/wiki/List_of_dyes |
This is a list of dynamical system and differential equation topics, by Wikipedia page. See also list of partial differential equation topics , list of equations . | https://en.wikipedia.org/wiki/List_of_dynamical_systems_and_differential_equations_topics |
This is a list of early microcomputers sold to hobbyists and developers. These microcomputers were often sold as " DIY " kits or pre-built machines in relatively small numbers in the mid-1970s. These systems were primarily used for teaching the use of microprocessors and supporting peripheral devices, and unlike home computers were rarely used with pre-written application software. Most early micros came without alphanumeric keyboards or displays, which had to be provided by the user. RAM was quite small in the unexpanded systems (a few hundred bytes to a few kilobytes). By 1976 the number of pre-assembled machines was growing, and the 1977 introduction of the "Trinity" of Commodore PET , TRS-80 and Apple II generally marks the end of the "early" microcomputer era, and the advent of the consumer home computer era that followed.
Before the advent of microprocessors, it was possible to build small computers using small-scale integrated circuits (ICs), where each IC contained only a few logic gates or flip-flops.
As microprocessors were developed, companies often released simple development systems to bootstrap the use of the processor. These systems were often converted by hobbyists into complete computer systems.
Intel's Intellec computers were a series of early microcomputers Intel produced starting in the 1970s as a development platform for their processors.
Many early microcomputers were available in Electronic kit form. Machines were sold in small numbers, with final assembly by the user. Kits took advantage of this by offering the system at a low price point. Kits were popular, beginning in 1975, with the introduction of the famous Altair 8800, but as sales volumes increased, kits became less common. The introduction of useful fully assembled machines in 1977 led to the rapid disappearance of kit systems for most users. The ZX81 was one of the last systems commonly available in both kit and assembled form.
Some magazines published plans and printed circuit board layouts from which a reader could in principle duplicate the project, although usually commercially made boards could be ordered to expedite assembly. Other kits varied from etched, drilled, printed circuit boards and a parts list to packages containing cases, power supplies, and all interconnections. All kits required significant assembly by the user.
A number of complete microcomputers were offered even before kits became popular, dating to as far back as 1972. For some time there was a major market for assembled versions of the Altair 8800, a market that grew significantly through the late 1970s and into the early 1980s. The introduction of three computers aimed at personal users in 1977, the Radio Shack TRS-80 , Apple II , and Commodore PET , significantly changed the American microcomputer market and led to the home computer revolution. | https://en.wikipedia.org/wiki/List_of_early_microcomputers |
This list is for ecoregions with high endemism . According to the World Wide Fund for Nature , the following ecoregions have the highest percentage of endemic plants. | https://en.wikipedia.org/wiki/List_of_ecoregions_with_high_endemism |
Edible salts , also known as table salts , are salts generally derived from mining ( rock salt ) or evaporation (including sea salt ). Edible salts may be identified by such characteristics as their geographic origin, method of preparation, natural impurities, additives, flavourings, or intended purpose (such as pickling or curing).
Brine
Celery salt
Cooking salt
Curing salt
Dairy salt
Garlic salt
Halite
Kitchen salt
Korean salt
Kosher salt
Pickling salt
Sea salt
Seasoned salt
Smoked salt
Artisanal salts are produced using specific, often traditional, methods, resulting in unique flavor profiles and textures. They may be sourced from specific geographical locations, such as coastal regions or salt flats.
Geographical Indication (GI) salts are salts that can only be produced in a specific geographical area. These regions often have unique environmental conditions, such as soil composition, climate, or mineral content, that contribute to the salt's distinct characteristics. To protect their authenticity and quality, many are legally protected such as that of the EU 's Protected Designation of Origin products .
Asín tibuok
Balinese sea salt
Black lava salt
Dead Sea salt
Fleur de sel
Jukyeom
Kala Namak
Kampot sea salt
Maldon Sea Salt
The movement of tectonic plates pushed the seabed up to form the Andes. The sea salt was locked into the rocks and filters out through the Qoripujio spring, which is then routed to roughly 5,000 evap ponds staggered down the valley in terraces.
Mongolian lake salt
Persian blue salt
Sale Marino di Trapani
Sel gris
Sel de Guérande | https://en.wikipedia.org/wiki/List_of_edible_salts |
This is a list of educational software that is computer software whose primary purpose is teaching or self-learning . | https://en.wikipedia.org/wiki/List_of_educational_software |
Below is the list of measuring instruments used in electrical and electronic work. | https://en.wikipedia.org/wiki/List_of_electrical_and_electronic_measuring_equipment |
This page is a comparison of electronic design automation (EDA) software which is used today to design the near totality of electronic devices. Modern electronic devices are too complex to be designed without the help of a computer. Electronic devices may consist of integrated circuits (ICs), printed circuit boards (PCBs), field-programmable gate arrays (FPGAs) or a combination of them. Integrated circuits may consist of a combination of digital and analog circuits. These circuits can contain a combination of transistors, resistors, capacitors or specialized components such as analog neural networks, antennas or fuses.
The design of each of these electronic devices generally proceeds from a high- to a low-level of abstraction. For FPGAs the low-level description consists of a binary file to be flashed into the gate array, while for an integrated circuit the low-level description consists of a layout file which describes the masks to be used for lithography inside a foundry.
Each design step requires specialized tools, and many of these tools can be used for designing multiple types of electronic circuits. For example, a program for high-level digital synthesis can usually be used both for IC digital design as well as for programming an FPGA. Similarly, a tool for schematic-capture and analog simulation can generally be used both for IC analog design and for PCB design.
In the case of integrated circuits (ICs) for example, a single chip may contain today more than 20 billion transistors (which is more than two transistors for every human on Earth) and, as a general rule, every single transistor in a chip must work as intended. Since a single VLSI mask set can cost up to 10-100 millions, trial and error approaches are not economically viable. To minimize the risk of any design mistakes, the design flow is heavily automatized. EDA software assists the designer in every step of the design process and every design step is accompanied by heavy test phases. Errors may be present in the high-level code already, such as for the Pentium FDIV floating-point unit bug , or it can be inserted all the way down to physical synthesis, such as a missing wire, or a timing violation .
The world of electronic design automation (EDA) software for integrated circuit (IC) design is dominated by the three vendors Synopsys , Cadence Design Systems and Siemens EDA (Formerly Mentor Graphics, acquired in 2017 by Siemens ) which have a revenue respectively of 4,2 billion US$, 3 billion US$ and 1,3 billion US$.
These vendors offer software bundles which allow to cover the full spectrum of IC design, from HDL synthesis to physical synthesis and verification.
The development of EDA software is tightly connected with the development of technology nodes . The properties of a specific semiconductor foundry, such as the transistor models, the physical characteristics and the design rules, are usually encoded in file formats which are proprietary to one or more EDA vendors. This set of files constitutes the process design kit (PDK) and it is usually developed as a joint effort between the foundry and an EDA vendor. Foundries therefore usually release PDKs which are compatible only for one specific EDA bundle. The information contained inside PDKs is usually considered confidential. PDKs are therefore usually protected by non disclosure agreements (NDAs) and may be shipped in an incomplete or in an encrypted form to the designers.
Of these, LTSpice and Micro-cap are free proprietary applications based on SPICE . Micro-Cap was released as freeware in July 2019, when its parent company Spectrum Software closed down while LTSpice has been free for a long time.
Free and open-source (FOSS) EDA software bundles are currently under fast development mainly thanks to the DARPA and Google 's openROAD project. The OpenROAD project offers a complete stack of tools from high-level synthesis down to layout generation [ 7 ] The flow includes Yosys for logic synthesis, OpenLane for physical synthesis and targets the SkyWater 130nm PDK. The flow is currently utilized to submit design for free fabrication at Google . [ 8 ] [ 9 ] [ better source needed ]
High-level synthesis software can generally be used for the design of both application-specific integrated circuits (ASICs) and field-programmable gate arrays (FPGAs). Most high-level synthesis software is used to edit and verify code written in one of the mainstream hardware description languages (HDL) like VHDL or Verilog . Other tools instead operate at a higher level of abstraction and allow to synthesize HDL code starting from languages like Chisel or SpinalHDL . The higher abstraction of such languages enables formal verification of HDL code. [ 10 ] [ 11 ] [ better source needed ]
This list does not include schematic editors or simulators since these can generally be used both for Integrated Circuits (ICs) and for Printed Circuit Board (PCB) as long as device models are available. | https://en.wikipedia.org/wiki/List_of_electrical_engineering_software |
This is a list of electricity-industry related organisations based in India. | https://en.wikipedia.org/wiki/List_of_electricity_organisations_in_India |
This article summarizes equations in the theory of electromagnetism .
Here subscripts e and m are used to differ between electric and magnetic charges . The definitions for monopoles are of theoretical interest, although real magnetic dipoles can be described using pole strengths. There are two possible units for monopole strength, Wb (Weber) and A m (Ampere metre). Dimensional analysis shows that magnetic charges relate by q m (Wb) = μ 0 q m (Am).
[I][L] (Am)
Contrary to the strong analogy between (classical) gravitation and electrostatics , there are no "centre of charge" or "centre of electrostatic attraction" analogues. [ citation needed ]
Electric transport
q e = ∬ σ e d S {\displaystyle q_{e}=\iint \sigma _{e}\mathrm {d} S}
q e = ∭ ρ e d V {\displaystyle q_{e}=\iiint \rho _{e}\mathrm {d} V}
V = voltage, not volume.
Electric fields
a = charge separation
directed from -ve to +ve charge
Theoretical: r 0 = ∞ {\displaystyle r_{0}=\infty \,\!} Practical: r 0 = R e a r t h {\displaystyle r_{0}=R_{\mathrm {earth} }\,\!} (Earth's radius)
Magnetic transport
q m = ∬ σ m d S {\displaystyle q_{m}=\iint \sigma _{m}\mathrm {d} S}
q m = ∭ ρ m d V {\displaystyle q_{m}=\iiint \rho _{m}\mathrm {d} V}
A m (− n + 1) , n = 1, 2, 3
[I][L] (Am)
A m s −1
[I][L][T] −1 (Am)
A m −1 s −1
[I][L] −1 [T] −1 (Am)
Magnetic fields
Two definitions are possible:
using pole strengths, m = q m a {\displaystyle \mathbf {m} =q_{m}\mathbf {a} \,\!}
using currents: m = N I A n ^ {\displaystyle \mathbf {m} =NIA\mathbf {\hat {n}} \,\!}
a = pole separation
N is the number of turns of conductor
most common: B = μ H = μ 0 ( H + M ) {\displaystyle \mathbf {B} =\mu \mathbf {H} =\mu _{0}\left(\mathbf {H} +\mathbf {M} \right)\,}
using pole strengths, [ 1 ] H = F q m {\displaystyle \mathbf {H} ={\mathbf {F} \over q_{m}}\,}
L = N ( d Φ d I ) {\displaystyle L=N\left({\mathrm {d} \Phi \over \mathrm {d} I}\right)\,\!}
L ( d I d t ) = − N V {\displaystyle L\left({\mathrm {d} I \over \mathrm {d} t}\right)=-NV\,\!}
M 1 = N ( d Φ 2 d I 1 ) {\displaystyle M_{1}=N\left({\mathrm {d} \Phi _{2} \over \mathrm {d} I_{1}}\right)\,\!}
M ( d I 2 d t ) = − N V 1 {\displaystyle M\left({\mathrm {d} I_{2} \over \mathrm {d} t}\right)=-NV_{1}\,\!}
1,2 subscripts refer to two conductors/inductors mutually inducing voltage/ linking magnetic flux through each other. They can be interchanged for the required conductor/inductor;
M 2 = N ( d Φ 1 d I 2 ) {\displaystyle M_{2}=N\left({\mathrm {d} \Phi _{1} \over \mathrm {d} I_{2}}\right)\,\!} M ( d I 1 d t ) = − N V 2 {\displaystyle M\left({\mathrm {d} I_{1} \over \mathrm {d} t}\right)=-NV_{2}\,\!}
DC circuits, general definitions
Power Supply
AC circuits
Z = R 2 + ( X L − X C ) 2 {\displaystyle Z={\sqrt {R^{2}+\left(X_{L}-X_{C}\right)^{2}}}\,\!}
N = number of turns of conductor
General Classical Equations
Δ V = − ∫ r 1 r 2 E ⋅ d r {\displaystyle \Delta V=-\int _{r_{1}}^{r_{2}}\mathbf {E} \cdot d\mathbf {r} \,\!}
U = − ∫ V d p ⋅ E {\displaystyle U=-\int _{V}\mathrm {d} \mathbf {p} \cdot \mathbf {E} }
General classical equations
B ( r ) = ∇ × A = μ 0 4 π ( 3 r ( m ⋅ r ) | r | 5 − m | r | 3 ) {\displaystyle \mathbf {B} ({\mathbf {r} })=\nabla \times {\mathbf {A} }={\frac {\mu _{0}}{4\pi }}\left({\frac {3\mathbf {r} (\mathbf {m} \cdot \mathbf {r} )}{\left|\mathbf {r} \right|^{5}}}-{\frac {\mathbf {m} }{\left|\mathbf {r} \right|^{3}}}\right)}
U = − ∫ V d m ⋅ B {\displaystyle U=-\int _{V}\mathrm {d} \mathbf {m} \cdot \mathbf {B} }
Below N = number of conductors or circuit components. Subscript net refers to the equivalent and resultant property value.
1 G n e t = ∑ i = 1 N 1 G i {\displaystyle {1 \over G_{\mathrm {net} }}=\sum _{i=1}^{N}{1 \over G_{i}}\,\!}
G n e t = ∑ i = 1 N G i {\displaystyle G_{\mathrm {net} }=\sum _{i=1}^{N}G_{i}\,\!}
1 C n e t = ∑ i = 1 N 1 C i {\displaystyle {1 \over C_{\mathrm {net} }}=\sum _{i=1}^{N}{1 \over C_{i}}\,\!} I n e t = I i {\displaystyle I_{\mathrm {net} }=I_{i}\,\!}
C n e t = ∑ i = 1 N C i {\displaystyle C_{\mathrm {net} }=\sum _{i=1}^{N}C_{i}\,\!} I n e t = ∑ i = 1 N I i {\displaystyle I_{\mathrm {net} }=\sum _{i=1}^{N}I_{i}\,\!}
V i = ∑ j = 1 N L i j d I j d t {\displaystyle V_{i}=\sum _{j=1}^{N}L_{ij}{\frac {\mathrm {d} I_{j}}{\mathrm {d} t}}\,\!}
R d q d t + q C = E {\displaystyle R{\mathrm {d} q \over \mathrm {d} t}+{q \over C}={\mathcal {E}}\,\!}
Capacitor charge q = C E ( 1 − e − t / R C ) {\displaystyle q=C{\mathcal {E}}\left(1-e^{-t/RC}\right)\,\!}
Capacitor discharge q = C E e − t / R C {\displaystyle q=C{\mathcal {E}}e^{-t/RC}\,\!}
L d I d t + R I = E {\displaystyle L{\mathrm {d} I \over \mathrm {d} t}+RI={\mathcal {E}}\,\!}
Inductor current rise I = E R ( 1 − e − R t / L ) {\displaystyle I={\frac {\mathcal {E}}{R}}\left(1-e^{-Rt/L}\right)\,\!}
Inductor current fall I = E R e − t / τ L = I 0 e − R t / L {\displaystyle I={\frac {\mathcal {E}}{R}}e^{-t/\tau _{L}}=I_{0}e^{-Rt/L}\,\!}
L d 2 q d t 2 + q C = E {\displaystyle L{\mathrm {d} ^{2}q \over \mathrm {d} t^{2}}+{q \over C}={\mathcal {E}}\,\!}
L d 2 q d t 2 + q C = E sin ( ω 0 t + ϕ ) {\displaystyle L{\mathrm {d} ^{2}q \over \mathrm {d} t^{2}}+{q \over C}={\mathcal {E}}\sin \left(\omega _{0}t+\phi \right)\,\!}
Circuit resonant frequency ω r e s = 1 L C {\displaystyle \omega _{\mathrm {res} }={1 \over {\sqrt {LC}}}\,\!}
Circuit charge q = q 0 cos ( ω t + ϕ ) {\displaystyle q=q_{0}\cos(\omega t+\phi )\,\!}
Circuit current I = − ω q 0 sin ( ω t + ϕ ) {\displaystyle I=-\omega q_{0}\sin(\omega t+\phi )\,\!}
Circuit electrical potential energy U E = q 2 2 C = q 0 2 cos 2 ( ω t + ϕ ) 2 C {\displaystyle U_{E}={q^{2} \over 2C}={q_{0}^{2}\cos ^{2}(\omega t+\phi ) \over 2C}\,\!}
Circuit magnetic potential energy U B = q 0 2 sin 2 ( ω t + ϕ ) 2 C {\displaystyle U_{B}={q_{0}^{2}\sin ^{2}(\omega t+\phi ) \over 2C}\,\!}
L d 2 q d t 2 + R d q d t + q C = E {\displaystyle L{\mathrm {d} ^{2}q \over \mathrm {d} t^{2}}+R{\mathrm {d} q \over \mathrm {d} t}+{q \over C}={\mathcal {E}}\,\!}
L d 2 q d t 2 + R d q d t + q C = E sin ( ω 0 t + ϕ ) {\displaystyle L{\mathrm {d} ^{2}q \over \mathrm {d} t^{2}}+R{\mathrm {d} q \over \mathrm {d} t}+{q \over C}={\mathcal {E}}\sin \left(\omega _{0}t+\phi \right)\,\!}
Circuit charge
q = q 0 e T − R t / 2 L cos ( ω ′ t + ϕ ) {\displaystyle q=q_{0}eT^{-Rt/2L}\cos(\omega 't+\phi )\,\!} | https://en.wikipedia.org/wiki/List_of_electromagnetism_equations |
This list of electronic Floras is arranged by country within continent. An electronic Flora is an online resource which provides descriptions of the associated plants, often also providing identification keys, or partial identification keys, to the plants described. Some Floras point to the literature associated with the plants of the region (flora Malesiana), others seek to show the plants of a region using images (flora of India), others give an inventory of the region's plants (flora of Pakistan).
Countries with sites listing both flora and fauna have also been included, since the sites provide a useful resource for those seeking to use a Flora. | https://en.wikipedia.org/wiki/List_of_electronic_Floras |
An electronic lab notebook (also known as electronic laboratory notebook , or ELN ) is a computer program designed to replace paper laboratory notebooks . Lab notebooks in general are used by scientists , engineers , and technicians to document research , experiments , and procedures performed in a laboratory. A lab notebook is often maintained to be a legal document and may be used in a court of law as evidence . Similar to an inventor's notebook , the lab notebook is also often referred to in patent prosecution and intellectual property litigation .
Electronic lab notebooks are a fairly new technology and offer many benefits to the user as well as organizations. For example: electronic lab notebooks are easier to search upon, simplify data copying and backups, and support collaboration amongst many users. [ 1 ] ELNs can have fine-grained access controls, and can be more secure than their paper counterparts. [ 2 ] They also allow the direct incorporation of data from instruments, replacing the practice of printing out data to be stapled into a paper notebook. [ 3 ] This is a list of ELN software packages. It is incomplete, as a recent review listed 96 active & 76 inactive (172 total) ELN products. [ 4 ] Notably, this review and other lists of ELN software often do not include widely used generic notetaking software like Onenote , Notion , Jupyter etc, due to their lack ELN nominal features like time-stamping and append-only editing. Some ELNs are web-based; others are used on premise and a few are available for both environments. | https://en.wikipedia.org/wiki/List_of_electronic_laboratory_notebook_software_packages |
This is a list of chemical elements and their atomic properties, ordered by atomic number ( Z ).
Since valence electrons are not clearly defined for the d-block and f-block elements, there not being a clear point at which further ionisation becomes unprofitable, a purely formal definition as number of electrons in the outermost shell has been used. | https://en.wikipedia.org/wiki/List_of_elements_by_atomic_properties |
Of the first 82 chemical elements in the periodic table , 80 have isotopes considered to be stable. [ 1 ] Overall, there are 251 known stable isotopes in total.
Atomic nuclei consist of protons and neutrons , which attract each other through the nuclear force , while protons repel each other via the electric force due to their positive charge . These two forces compete, leading to some combinations of neutrons and protons being more stable than others. Neutrons stabilize the nucleus, because they attract protons, which helps offset the electrical repulsion between protons. As a result, as the number of protons increases, an increasing ratio of neutrons to protons is needed to form a stable nucleus; if too many or too few neutrons are present with regard to the optimum ratio, the nucleus becomes unstable and subject to certain types of nuclear decay . Unstable isotopes decay through various radioactive decay pathways , most commonly alpha decay , beta decay , or electron capture . Many rare types of decay, such as spontaneous fission or cluster decay , are known. (See Radioactive decay for details.) [ citation needed ]
Of the first 82 elements in the periodic table , 80 have isotopes considered to be stable. [ 1 ] The 83rd element, bismuth, was traditionally regarded as having the heaviest stable isotope, bismuth-209 , but in 2003 researchers in Orsay , France, measured the half-life of 209 Bi to be 1.9 × 10 19 years . [ 2 ] [ 3 ] Technetium and promethium ( atomic numbers 43 and 61, respectively [ a ] ) and all the elements with an atomic number over 82 only have isotopes that are known to decompose through radioactive decay . No undiscovered elements are expected to be stable; therefore, lead is considered the heaviest stable element. However, it is possible that some isotopes that are now considered stable will be revealed to decay with extremely long half-lives (as with 209 Bi ). This list depicts what is agreed upon by the consensus of the scientific community as of 2023. [ 1 ]
For each of the 80 stable elements, the number of the stable isotopes is given. Only 90 isotopes are expected to be perfectly stable, and an additional 161 are energetically unstable, [ citation needed ] but have never been observed to decay. Thus, 251 isotopes ( nuclides ) are stable by definition (including tantalum-180m, for which no decay has yet been observed). Those that may in the future be found to be radioactive are expected to have half-lives longer than 10 22 years (for example, xenon-134). [ citation needed ]
In April 2019 it was announced that the half-life of xenon-124 had been measured to 1.8 × 10 22 years. This is the longest half-life directly measured for any unstable isotope; [ 4 ] only the half-life of tellurium-128 is longer. [ citation needed ]
Of the chemical elements, only 1 element ( tin ) has 10 such stable isotopes, 5 have 7 stable isotopes, 7 have 6 stable isotopes, 11 have 5 stable isotopes, 9 have 4 stable isotopes, 5 have 3 stable isotopes, 16 have 2 stable isotopes, and 26 have 1 stable isotope. [ 1 ]
Additionally, about 31 nuclides of the naturally occurring elements have unstable isotopes with a half-life larger than the age of the Solar System (~10 9 years or more). [ b ] An additional four nuclides have half-lives longer than 100 million years, which is far less than the age of the Solar System, but long enough for some of them to have survived. These 35 radioactive naturally occurring nuclides comprise the radioactive primordial nuclides . The total number of primordial nuclides is then 251 (the stable nuclides) plus the 35 radioactive primordial nuclides, for a total of 286 primordial nuclides. This number is subject to change if new shorter-lived primordials are identified on Earth. [ citation needed ]
One of the primordial nuclides is tantalum-180m , which is predicted to have a half-life in excess of 10 15 years, but has never been observed to decay. The even-longer half-life of 2.2 × 10 24 years of tellurium-128 was measured by a unique method of detecting its radiogenic daughter xenon-128 and is the longest known experimentally measured half-life. [ 5 ] Another notable example is the only naturally occurring isotope of bismuth, bismuth-209 , which has been predicted to be unstable with a very long half-life, but has been observed to decay. Because of their long half-lives, such isotopes are still found on Earth in various quantities, and together with the stable isotopes they are called primordial isotopes . All the primordial isotopes are given in order of their decreasing abundance on Earth . [ c ] For a list of primordial nuclides in order of half-life, see List of nuclides . [ citation needed ]
118 chemical elements are known to exist. All elements to element 94 are found in nature, and the remainder of the discovered elements are artificially produced, with isotopes all known to be highly radioactive with relatively short half-lives (see below). The elements in this list are ordered according to the lifetime of their most stable isotope. [ 1 ] Of these, three elements ( bismuth , thorium , and uranium ) are primordial because they have half-lives long enough to still be found on the Earth, [ d ] while all the others are produced either by radioactive decay or are synthesized in laboratories and nuclear reactors . Only 13 of the 38 known-but-unstable elements have isotopes with a half-life of at least 100 years. Every known isotope of the remaining 25 elements is highly radioactive; these are used in academic research and sometimes in industry and medicine. [ e ] Some of the heavier elements in the periodic table may be revealed to have yet-undiscovered isotopes with longer lifetimes than those listed here. [ f ]
About 338 nuclides are found naturally on Earth. These comprise 251 stable isotopes, and with the addition of the 35 long-lived radioisotopes with half-lives longer than 100 million years, a total of 286 primordial nuclides , as noted above. The nuclides found naturally comprise not only the 286 primordials, but also include about 52 more short-lived isotopes (defined by a half-life less than 100 million years, too short to have survived from the formation of the Earth) that are daughters of primordial isotopes (such as radium from uranium ); or else are made by energetic natural processes, such as carbon-14 made from atmospheric nitrogen by bombardment from cosmic rays . [ citation needed ]
An even number of protons or neutrons is more stable (higher binding energy ) because of pairing effects , so even–even nuclides are much more stable than odd–odd. One effect is that there are few stable odd–odd nuclides: in fact only five are stable, with another four having half-lives longer than a billion years. [ citation needed ]
Another effect is to prevent beta decay of many even–even nuclides into another even–even nuclide of the same mass number but lower energy, because decay proceeding one step at a time would have to pass through an odd–odd nuclide of higher energy. ( Double beta decay directly from even–even to even–even, skipping over an odd-odd nuclide, is only occasionally possible, and is a process so strongly hindered that it has a half-life greater than a billion times the age of the universe .) This makes for a larger number of stable even–even nuclides, up to three for some mass numbers , and up to seven for some atomic (proton) numbers and at least four for all stable even- Z elements beyond iron (except strontium and lead ). [ citation needed ]
Since a nucleus with an odd number of protons is relatively less stable, odd-numbered elements tend to have fewer stable isotopes. Of the 26 " monoisotopic " elements that have only a single stable isotope, all but one have an odd atomic number—the single exception being beryllium . In addition, no odd-numbered element has more than two stable isotopes, while every even-numbered element with stable isotopes, except for helium, beryllium, and carbon, has at least three. Only a single odd-numbered element, potassium , has three primordial isotopes; none have more than three. [ citation needed ]
The following tables give the elements with primordial nuclides , which means that the element may still be identified on Earth from natural sources, having been present since the Earth was formed out of the solar nebula. Thus, none are shorter-lived daughters of longer-lived parental primordials. Two nuclides which have half-lives long enough to be primordial, but have not yet been conclusively observed as such ( 244 Pu and 146 Sm), have been excluded. [ citation needed ]
The tables of elements are sorted in order of decreasing number of nuclides associated with each element. (For a list sorted entirely in terms of half-lives of nuclides, with mixing of elements, see List of nuclides .) Stable and unstable (marked decays ) nuclides are given, with symbols for unstable (radioactive) nuclides in italics. Note that the sorting does not quite give the elements purely in order of stable nuclides, since some elements have a larger number of long-lived unstable nuclides, which place them ahead of elements with a larger number of stable nuclides. By convention, nuclides are counted as "stable" if they have never been observed to decay by experiment or from observation of decay products (extremely long-lived nuclides unstable only in theory, such as tantalum-180m, are counted as stable). [ citation needed ]
The first table is for even-atomic numbered elements, which tend to have far more primordial nuclides, due to the stability conferred by proton-proton pairing. A second separate table is given for odd-atomic numbered elements, which tend to have far fewer stable and long-lived (primordial) unstable nuclides. [ citation needed ] | https://en.wikipedia.org/wiki/List_of_elements_by_stability_of_isotopes |
Chemical symbols are the abbreviations used in chemistry , mainly for chemical elements ; but also for functional groups , chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols , normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.
Earlier symbols for chemical elements stem from classical Latin and Greek vocabulary. For some elements, this is because the material was known in ancient times, while for others, the name is a more recent invention. For example, Pb is the symbol for lead ( plumbum in Latin); Hg is the symbol for mercury ( hydrargyrum in Greek); and He is the symbol for helium (a Neo-Latin name) because helium was not known in ancient Roman times. Some symbols come from other sources, like W for tungsten ( Wolfram in German) which was not known in Roman times.
A three-letter temporary symbol may be assigned to a newly synthesized (or not yet synthesized) element. For example, "Uno" was the temporary symbol for hassium (element 108) which had the temporary name of unniloctium , based on the digits of its atomic number. There are also some historical symbols that are no longer officially used.
In addition to the letters for the element itself, additional details may be added to the symbol as superscripts or subscripts a particular isotope , ionization , or oxidation state , or other atomic detail. [ 1 ] A few isotopes have their own specific symbols rather than just an isotopic detail added to their element symbol.
Attached subscripts or superscripts specifying a nuclide or molecule have the following meanings and positions:
Many functional groups also have their own chemical symbol, e.g. Ph for the phenyl group , and Me for the methyl group .
A list of current, dated, as well as proposed and historical signs and symbols is included here with its signification . Also given is each element's atomic number , atomic weight , or the atomic mass of the most stable isotope , group and period numbers on the periodic table , and etymology of the symbol.
The following is a list of symbols and names formerly used or suggested for elements, including symbols for placeholder names and names given by discredited claimants for discovery.
These symbols are based on systematic element names , which are now replaced by trivial (non-systematic) element names and symbols. Data is given in order of: atomic number , systematic symbol, systematic name; trivial symbol, trivial name.
When elements beyond oganesson (starting with ununennium , Uue, element 119), are discovered; their systematic name and symbol will presumably be superseded by a trivial name and symbol.
The following ideographic symbols were used in alchemy to denote elements known since ancient times. Not included in this list are spurious elements, such as the classical elements fire and water or phlogiston , and substances now known to be compounds. Many more symbols were in at least sporadic use: one early 17th-century alchemical manuscript lists 22 symbols for mercury alone. [ 10 ]
Planetary names and symbols for the metals – the seven planets and seven metals known since Classical times in Europe and the Mideast – was ubiquitous in alchemy. The association of what are anachronistically known as planetary metals started breaking down with the discovery of antimony, bismuth and zinc in the 16th century. Alchemists would typically call the metals by their planetary names, e.g. "Saturn" for lead and "Mars" for iron; compounds of tin, iron and silver continued to be called "jovial", "martial" and "lunar"; or "of Jupiter", "of Mars" and "of the moon", through the 17th century. The tradition remains today with the name of the element mercury, where chemists decided the planetary name was preferable to common names like "quicksilver", and in a few archaic terms such as lunar caustic (silver nitrate) and saturnism (lead poisoning). [ 10 ]
The following symbols were employed by John Dalton in the early 1800s as the periodic table of elements was being formulated. Not included in this list are substances now known to be compounds, such as certain rare-earth mineral blends. Modern alphabetic notation was introduced in 1814 by Jöns Jakob Berzelius ; its precursor can be seen in Dalton's circled letters for the metals, especially in his augmented table from 1810. [ 11 ] A trace of Dalton's conventions also survives in ball-and-stick models of molecules, where balls for carbon are black and for oxygen red.
The following is a list of isotopes which have been given unique symbols. This is not a list of current systematic symbols (in the u Atom form); such a list can instead be found in Template:Navbox element isotopes . The symbols for isotopes of hydrogen , deuterium (D) and tritium (T), are still in use today, as is thoron (Tn) for radon-220 (though not actinon ; An usually instead means a generic actinide ). Heavy water and other deuterated solvents are commonly used in chemistry, and it is convenient to use a single character rather than a symbol with a subscript in these cases. The practice also continues with tritium compounds. When the name of the solvent is given, a lowercase d is sometimes used. For example, d 6 -benzene or C 6 D 6 can be used instead of C 6 [ 2 H 6 ]. [ 14 ]
The symbols for isotopes of elements other than hydrogen and radon are no longer used in the scientific community. Many of these symbols were designated during the early years of radiochemistry , and several isotopes (namely those in the decay chains of actinium , radium , and thorium ) bear placeholder names using the early naming system devised by Ernest Rutherford . [ 15 ]
General:
From organic chemistry:
Exotic atoms:
Hazard pictographs are another type of symbols used in chemistry. | https://en.wikipedia.org/wiki/List_of_elements_by_symbol |
This article lists software emulators . | https://en.wikipedia.org/wiki/List_of_emulators |
Endophytes are micro-organisms living within the tissue of a plant as endosymbionts , without causing symptoms of disease . Some of them are mutualistic symbionts with beneficial effects on their host, such as improved growth or resistance against disease or environmental stress , and are being used as microbial inoculants . However, pathogens and saprophytes may also be endophytic at some point of their life cycle. Endophytes are distinct from mycorrhizal fungi or rhizosphere microbes in that they live entirely within the plant. Most endophytes known are bacteria or fungi , although there are also some endophytic algae and oomycetes .
This list contains genera with endophytic species (but which may also have non-endophytic species). Species are only listed in notable cases. Where specific variants or cultivars of a species are endophytic, this is detailed on the taxon's page. The host range is "wide" when it does not include only a specific lineage of plants; in that case, the lineage is given.
See also Rhizobia for the nitrogen-fixing bacteria on roots of legumes (Fabaceae). | https://en.wikipedia.org/wiki/List_of_endophytes |
Engineering is the discipline and profession that applies scientific theories, mathematical methods, and empirical evidence to design, create, and analyze technological solutions, balancing technical requirements with concerns or constraints on safety, human factors, physical limits, regulations, practicality, and cost, and often at an industrial scale. In the contemporary era , engineering is generally considered to consist of the major primary branches of biomedical engineering , chemical engineering , civil engineering , electrical engineering , materials engineering and mechanical engineering . [ 1 ] There are numerous other engineering sub-disciplines and interdisciplinary subjects that may or may not be grouped with these major engineering branches.
Biomedical engineering is the application of engineering principles and design concepts to medicine and biology for healthcare applications (e.g., diagnostic or therapeutic purposes).
Chemical engineering is the application of chemical, physical, and biological sciences to developing technological solutions from raw materials or chemicals.
Civil engineering comprises the design, construction, and maintenance of the physical and natural built environments.
Electrical engineering comprises the study and application of electricity , electronics and electromagnetism .
Materials engineering is the application of material science and engineering principles to understand the properties of materials. Material science emerged in the mid-20th century, grouping together fields which had previously been considered unrelated. Materials engineering is thus much more interdisciplinary than the other major engineering branches.
Mechanical engineering comprises the design and analysis of heat and mechanical power for the operation of machines and mechanical systems. [ 3 ]
Field of engineering that designs, constructs, and maintains different types of power plants . Serves as the prime mover to produce electricity. | https://en.wikipedia.org/wiki/List_of_engineering_branches |
An engineering society is a professional organization for engineers of various disciplines . Some are umbrella type organizations which accept many different disciplines, while others are discipline-specific. Many award professional designations, such as European Engineer , professional engineer , chartered engineer , incorporated engineer or similar. There are also many student-run engineering societies, commonly at universities or technical colleges.
In Canada, the term "engineering society" sometimes refers to organizations of engineering students as opposed to professional societies of engineers. The Canadian Federation of Engineering Students , whose membership consists of most of the engineering student societies from across Canada (see below), is the national association of undergraduate engineering student societies in Canada.
Canada also has many traditions related to the calling of an engineer .
The Engineering Institute of Canada (French: l'Institut Canadien des ingénieurs) has the following member societies: [ 1 ]
In the Philippines , the Professional Regulation Commission is a three-man commission attached to the office of the president of the Philippines . Its mandate is to regulate and supervise the practice of professionals (except lawyers ) who constitute the highly skilled manpower of the country. As the agency-in-charge of the professional sector, the PRC plays a strategic role in developing the corps of professionals for industry, commerce, governance and the economy.
In the United Kingdom , the Engineering Council is the regulatory body for the engineering profession. The Engineering Council was incorporated by Royal charter in 1981 and controls the award of chartered engineer , incorporated engineer , engineering technician , and information and communications technology technician titles, through licences issued to thirty six recognised Institutions. There are also 19 professional affiliate institutions, not licensed, but with close associations to the Engineering Council.
The Royal Academy of Engineering is the national academy for engineering. | https://en.wikipedia.org/wiki/List_of_engineering_societies |
This is a list of notable vendors of enterprise portals . An enterprise portal is a framework for integrating information, people and processes across organizational boundaries. | https://en.wikipedia.org/wiki/List_of_enterprise_portal_vendors |
This is a list of scholarly, peer-reviewed academic journals focused on the biophysical environment and/or humans' relations with it. Inclusion of journals focused on the built environment is appropriate. Included in this list are journals from a wide variety of interdisciplinary fields including from the environmental sciences , environmental social sciences , environmental humanities , etc. | https://en.wikipedia.org/wiki/List_of_environmental_journals |
Environmental sampling techniques are used in biology, ecology and conservation as part of scientific studies to learn about the flora and fauna of a particular area and establish a habitat's biodiversity , the abundance of species and the conditions in which these species live amongst other information. [ 1 ] Where species are caught, researchers often then take the trapped organisms for further study in a lab or are documented by a researcher in the field before the animal is released. This information can then be used to better understand the environment, its ecology, the behaviour of species and how organisms interact with one another and their environment. Here is a list of some sampling techniques and equipment used in environmental sampling: | https://en.wikipedia.org/wiki/List_of_environmental_sampling_techniques |
This is a list of equations , by Wikipedia page under appropriate bands of their field.
The following equations are named after researchers who discovered them. | https://en.wikipedia.org/wiki/List_of_equations |
Classical mechanics is the branch of physics used to describe the motion of macroscopic objects. [ 1 ] It is the most familiar of the theories of physics. The concepts it covers, such as mass , acceleration , and force , are commonly used and known. [ 2 ] The subject is based upon a three-dimensional Euclidean space with fixed axes, called a frame of reference. The point of concurrency of the three axes is known as the origin of the particular space. [ 3 ]
Classical mechanics utilises many equations —as well as other mathematical concepts—which relate various physical quantities to one another. These include differential equations , manifolds , Lie groups , and ergodic theory . [ 4 ] This article gives a summary of the most important of these.
This article lists equations from Newtonian mechanics , see analytical mechanics for the more general formulation of classical mechanics (which includes Lagrangian and Hamiltonian mechanics ).
m = ∬ σ d S {\displaystyle m=\iint \sigma \,\mathrm {d} S}
m = ∭ ρ d V {\displaystyle m=\iiint \rho \,\mathrm {d} V}
m = r m {\displaystyle \mathbf {m} =\mathbf {r} m}
Discrete masses about an axis x i {\displaystyle x_{i}} : m = ∑ i = 1 N r i m i {\displaystyle \mathbf {m} =\sum _{i=1}^{N}\mathbf {r} _{i}m_{i}}
Continuum of mass about an axis x i {\displaystyle x_{i}} : m = ∫ ρ ( r ) x i d r {\displaystyle \mathbf {m} =\int \rho \left(\mathbf {r} \right)x_{i}\mathrm {d} \mathbf {r} }
(Symbols vary)
Discrete masses: r c o m = 1 M ∑ i r i m i = 1 M ∑ i m i {\displaystyle \mathbf {r} _{\mathrm {com} }={\frac {1}{M}}\sum _{i}\mathbf {r} _{i}m_{i}={\frac {1}{M}}\sum _{i}\mathbf {m} _{i}}
Mass continuum: r c o m = 1 M ∫ d m = 1 M ∫ r d m = 1 M ∫ r ρ d V {\displaystyle \mathbf {r} _{\mathrm {com} }={\frac {1}{M}}\int \mathrm {d} \mathbf {m} ={\frac {1}{M}}\int \mathbf {r} \,\mathrm {d} m={\frac {1}{M}}\int \mathbf {r} \rho \,\mathrm {d} V}
I = ∑ i m i ⋅ r i = ∑ i | r i | 2 m {\displaystyle I=\sum _{i}\mathbf {m} _{i}\cdot \mathbf {r} _{i}=\sum _{i}\left|\mathbf {r} _{i}\right|^{2}m}
Mass continuum: I = ∫ | r | 2 d m = ∫ r ⋅ d m = ∫ | r | 2 ρ d V {\displaystyle I=\int \left|\mathbf {r} \right|^{2}\mathrm {d} m=\int \mathbf {r} \cdot \mathrm {d} \mathbf {m} =\int \left|\mathbf {r} \right|^{2}\rho \,\mathrm {d} V}
Most of the time we can set r 0 = 0 if particles are orbiting about axes intersecting at a common point.
Torque
Every conservative force has a potential energy . By following two principles one can consistently assign a non-relative value to U :
where q = q ( t ) {\displaystyle \mathbf {q} =\mathbf {q} (t)} and p = p ( t ) are vectors of the generalized coords and momenta, as functions of time
In the following rotational definitions, the angle can be any angle about the specified axis of rotation. It is customary to use θ , but this does not have to be the polar angle used in polar coordinate systems. The unit axial vector
n ^ = e ^ r × e ^ θ {\displaystyle \mathbf {\hat {n}} =\mathbf {\hat {e}} _{r}\times \mathbf {\hat {e}} _{\theta }}
defines the axis of rotation, e ^ r {\displaystyle \scriptstyle \mathbf {\hat {e}} _{r}} = unit vector in direction of r , e ^ θ {\displaystyle \scriptstyle \mathbf {\hat {e}} _{\theta }} = unit vector tangential to the angle.
v a v e r a g e = Δ r Δ t {\displaystyle \mathbf {v} _{\mathrm {average} }={\Delta \mathbf {r} \over \Delta t}} Instantaneous:
v = d r d t {\displaystyle \mathbf {v} ={d\mathbf {r} \over dt}}
a a v e r a g e = Δ v Δ t {\displaystyle \mathbf {a} _{\mathrm {average} }={\frac {\Delta \mathbf {v} }{\Delta t}}}
Instantaneous:
a = d v d t = d 2 r d t 2 {\displaystyle \mathbf {a} ={\frac {d\mathbf {v} }{dt}}={\frac {d^{2}\mathbf {r} }{dt^{2}}}}
α = d ω d t = n ^ d 2 θ d t 2 {\displaystyle {\boldsymbol {\alpha }}={\frac {{\rm {d}}{\boldsymbol {\omega }}}{{\rm {d}}t}}=\mathbf {\hat {n}} {\frac {{\rm {d}}^{2}\theta }{{\rm {d}}t^{2}}}}
Rotating rigid body:
a = α × r + ω × v {\displaystyle \mathbf {a} ={\boldsymbol {\alpha }}\times \mathbf {r} +{\boldsymbol {\omega }}\times \mathbf {v} }
j a v e r a g e = Δ a Δ t {\displaystyle \mathbf {j} _{\mathrm {average} }={\frac {\Delta \mathbf {a} }{\Delta t}}}
Instantaneous:
j = d a d t = d 2 v d t 2 = d 3 r d t 3 {\displaystyle \mathbf {j} ={\frac {d\mathbf {a} }{dt}}={\frac {d^{2}\mathbf {v} }{dt^{2}}}={\frac {d^{3}\mathbf {r} }{dt^{3}}}}
ζ = d α d t = n ^ d 2 ω d t 2 = n ^ d 3 θ d t 3 {\displaystyle {\boldsymbol {\zeta }}={\frac {{\rm {d}}{\boldsymbol {\alpha }}}{{\rm {d}}t}}=\mathbf {\hat {n}} {\frac {{\rm {d}}^{2}\omega }{{\rm {d}}t^{2}}}=\mathbf {\hat {n}} {\frac {{\rm {d}}^{3}\theta }{{\rm {d}}t^{3}}}}
Rotating rigid body:
j = ζ × r + α × a {\displaystyle \mathbf {j} ={\boldsymbol {\zeta }}\times \mathbf {r} +{\boldsymbol {\alpha }}\times \mathbf {a} }
p = m v {\displaystyle \mathbf {p} =m\mathbf {v} }
For a rotating rigid body:
p = ω × m {\displaystyle \mathbf {p} ={\boldsymbol {\omega }}\times \mathbf {m} }
Angular momentum is the "amount of rotation":
L = r × p = I ⋅ ω {\displaystyle \mathbf {L} =\mathbf {r} \times \mathbf {p} =\mathbf {I} \cdot {\boldsymbol {\omega }}}
and the cross-product is a pseudovector i.e. if r and p are reversed in direction (negative), L is not.
In general I is an order-2 tensor , see above for its components. The dot · indicates tensor contraction .
F = d p d t = d ( m v ) d t = m a + v d m d t {\displaystyle {\begin{aligned}\mathbf {F} &={\frac {d\mathbf {p} }{dt}}={\frac {d(m\mathbf {v} )}{dt}}\\&=m\mathbf {a} +\mathbf {v} {\frac {{\rm {d}}m}{{\rm {d}}t}}\\\end{aligned}}}
For a number of particles, the equation of motion for one particle i is: [ 7 ]
d p i d t = F E + ∑ i ≠ j F i j {\displaystyle {\frac {\mathrm {d} \mathbf {p} _{i}}{\mathrm {d} t}}=\mathbf {F} _{E}+\sum _{i\neq j}\mathbf {F} _{ij}}
where p i = momentum of particle i , F ij = force on particle i by particle j , and F E = resultant external force (due to any agent not part of system). Particle i does not exert a force on itself.
Torque τ is also called moment of a force, because it is the rotational analogue to force: [ 8 ]
τ = d L d t = r × F = d ( I ⋅ ω ) d t {\displaystyle {\boldsymbol {\tau }}={\frac {{\rm {d}}\mathbf {L} }{{\rm {d}}t}}=\mathbf {r} \times \mathbf {F} ={\frac {{\rm {d}}(\mathbf {I} \cdot {\boldsymbol {\omega }})}{{\rm {d}}t}}}
For rigid bodies, Newton's 2nd law for rotation takes the same form as for translation:
τ = d L d t = d ( I ⋅ ω ) d t = d I d t ⋅ ω + I ⋅ α {\displaystyle {\begin{aligned}{\boldsymbol {\tau }}&={\frac {{\rm {d}}\mathbf {L} }{{\rm {d}}t}}={\frac {{\rm {d}}(\mathbf {I} \cdot {\boldsymbol {\omega }})}{{\rm {d}}t}}\\&={\frac {{\rm {d}}\mathbf {I} }{{\rm {d}}t}}\cdot {\boldsymbol {\omega }}+\mathbf {I} \cdot {\boldsymbol {\alpha }}\\\end{aligned}}}
Likewise, for a number of particles, the equation of motion for one particle i is: [ 9 ]
d L i d t = τ E + ∑ i ≠ j τ i j {\displaystyle {\frac {\mathrm {d} \mathbf {L} _{i}}{\mathrm {d} t}}={\boldsymbol {\tau }}_{E}+\sum _{i\neq j}{\boldsymbol {\tau }}_{ij}}
Y = d F d t = d 2 p d t 2 = d 2 ( m v ) d t 2 = m j + 2 a d m d t + v d 2 m d t 2 {\displaystyle {\begin{aligned}\mathbf {Y} &={\frac {d\mathbf {F} }{dt}}={\frac {d^{2}\mathbf {p} }{dt^{2}}}={\frac {d^{2}(m\mathbf {v} )}{dt^{2}}}\\[1ex]&=m\mathbf {j} +\mathbf {2a} {\frac {{\rm {d}}m}{{\rm {d}}t}}+\mathbf {v} {\frac {{\rm {d^{2}}}m}{{\rm {d}}t^{2}}}\end{aligned}}}
For constant mass, it becomes; Y = m j {\displaystyle \mathbf {Y} =m\mathbf {j} }
Rotatum Ρ is also called moment of a Yank, because it is the rotational analogue to yank:
P = d τ d t = r × Y = d ( I ⋅ α ) d t {\displaystyle {\boldsymbol {\mathrm {P} }}={\frac {{\rm {d}}{\boldsymbol {\tau }}}{{\rm {d}}t}}=\mathbf {r} \times \mathbf {Y} ={\frac {{\rm {d}}(\mathbf {I} \cdot {\boldsymbol {\alpha }})}{{\rm {d}}t}}}
Δ p = ∫ F d t {\displaystyle \Delta \mathbf {p} =\int \mathbf {F} \,dt}
For constant force F :
Δ p = F Δ t {\displaystyle \Delta \mathbf {p} =\mathbf {F} \Delta t}
Δ L = ∫ τ d t {\displaystyle \Delta \mathbf {L} =\int {\boldsymbol {\tau }}\,dt}
For constant torque τ :
Δ L = τ Δ t {\displaystyle \Delta \mathbf {L} ={\boldsymbol {\tau }}\Delta t}
The precession angular speed of a spinning top is given by:
Ω = w r I ω {\displaystyle {\boldsymbol {\Omega }}={\frac {wr}{I{\boldsymbol {\omega }}}}}
where w is the weight of the spinning flywheel.
The mechanical work done by an external agent on a system is equal to the change in kinetic energy of the system:
The work done W by an external agent which exerts a force F (at r ) and torque τ on an object along a curved path C is:
W = Δ T = ∫ C ( F ⋅ d r + τ ⋅ n d θ ) {\displaystyle W=\Delta T=\int _{C}\left(\mathbf {F} \cdot \mathrm {d} \mathbf {r} +{\boldsymbol {\tau }}\cdot \mathbf {n} \,{\mathrm {d} \theta }\right)}
where θ is the angle of rotation about an axis defined by a unit vector n .
The change in kinetic energy for an object initially traveling at speed v 0 {\displaystyle v_{0}} and later at speed v {\displaystyle v} is: Δ E k = W = 1 2 m ( v 2 − v 0 2 ) {\displaystyle \Delta E_{k}=W={\frac {1}{2}}m(v^{2}-{v_{0}}^{2})}
For a stretched spring fixed at one end obeying Hooke's law , the elastic potential energy is
Δ E p = 1 2 k ( r 2 − r 1 ) 2 {\displaystyle \Delta E_{p}={\frac {1}{2}}k(r_{2}-r_{1})^{2}}
where r 2 and r 1 are collinear coordinates of the free end of the spring, in the direction of the extension/compression, and k is the spring constant.
Euler also worked out analogous laws of motion to those of Newton, see Euler's laws of motion . These extend the scope of Newton's laws to rigid bodies, but are essentially the same as above. A new equation Euler formulated is: [ 10 ]
I ⋅ α + ω × ( I ⋅ ω ) = τ {\displaystyle \mathbf {I} \cdot {\boldsymbol {\alpha }}+{\boldsymbol {\omega }}\times \left(\mathbf {I} \cdot {\boldsymbol {\omega }}\right)={\boldsymbol {\tau }}}
where I is the moment of inertia tensor .
The previous equations for planar motion can be used here: corollaries of momentum, angular momentum etc. can immediately follow by applying the above definitions. For any object moving in any path in a plane,
r = r ( t ) = r r ^ {\displaystyle \mathbf {r} =\mathbf {r} (t)=r{\hat {\mathbf {r} }}}
the following general results apply to the particle.
r = r ( r , θ , t ) = r r ^ {\displaystyle \mathbf {r} =\mathbf {r} \left(r,\theta ,t\right)=r{\hat {\mathbf {r} }}}
v = r ^ d r d t + r ω θ ^ {\displaystyle \mathbf {v} ={\hat {\mathbf {r} }}{\frac {\mathrm {d} r}{\mathrm {d} t}}+r\omega {\hat {\mathbf {\theta } }}}
p = m ( r ^ d r d t + r ω θ ^ ) {\displaystyle \mathbf {p} =m\left({\hat {\mathbf {r} }}{\frac {\mathrm {d} r}{\mathrm {d} t}}+r\omega {\hat {\mathbf {\theta } }}\right)}
Angular momenta L = m r × ( r ^ d r d t + r ω θ ^ ) {\displaystyle \mathbf {L} =m\mathbf {r} \times \left({\hat {\mathbf {r} }}{\frac {\mathrm {d} r}{\mathrm {d} t}}+r\omega {\hat {\mathbf {\theta } }}\right)}
a = ( d 2 r d t 2 − r ω 2 ) r ^ + ( r α + 2 ω d r d t ) θ ^ {\displaystyle \mathbf {a} =\left({\frac {\mathrm {d} ^{2}r}{\mathrm {d} t^{2}}}-r\omega ^{2}\right){\hat {\mathbf {r} }}+\left(r\alpha +2\omega {\frac {\mathrm {d} r}{{\rm {d}}t}}\right){\hat {\mathbf {\theta } }}}
F ⊥ = − m ω 2 R r ^ = − ω 2 m {\displaystyle \mathbf {F} _{\bot }=-m\omega ^{2}R{\hat {\mathbf {r} }}=-\omega ^{2}\mathbf {m} }
where again m is the mass moment, and the Coriolis force is
F c = 2 ω m d r d t θ ^ = 2 ω m v θ ^ {\displaystyle \mathbf {F} _{c}=2\omega m{\frac {{\rm {d}}r}{{\rm {d}}t}}{\hat {\mathbf {\theta } }}=2\omega mv{\hat {\mathbf {\theta } }}}
The Coriolis acceleration and force can also be written:
F c = m a c = − 2 m ω × v {\displaystyle \mathbf {F} _{c}=m\mathbf {a} _{c}=-2m{\boldsymbol {\omega \times v}}}
For a massive body moving in a central potential due to another object, which depends only on the radial separation between the centers of masses of the two objects, the equation of motion is:
d 2 d θ 2 ( 1 r ) + 1 r = − μ r 2 l 2 F ( r ) {\displaystyle {\frac {d^{2}}{d\theta ^{2}}}\left({\frac {1}{\mathbf {r} }}\right)+{\frac {1}{\mathbf {r} }}=-{\frac {\mu \mathbf {r} ^{2}}{\mathbf {l} ^{2}}}\mathbf {F} (\mathbf {r} )}
These equations can be used only when acceleration is constant. If acceleration is not constant then the general calculus equations above must be used, found by integrating the definitions of position, velocity and acceleration (see above).
For classical (Galileo-Newtonian) mechanics, the transformation law from one inertial or accelerating (including rotation) frame (reference frame traveling at constant velocity - including zero) to another is the Galilean transform.
Unprimed quantities refer to position, velocity and acceleration in one frame F; primed quantities refer to position, velocity and acceleration in another frame F' moving at translational velocity V or angular velocity Ω relative to F. Conversely F moves at velocity (— V or — Ω ) relative to F'. The situation is similar for relative accelerations.
V = Constant relative velocity between two inertial frames F and F'. A = (Variable) relative acceleration between two accelerating frames F and F'.
r ′ = r + V t {\displaystyle \mathbf {r} '=\mathbf {r} +\mathbf {V} t}
Relative velocity v ′ = v + V {\displaystyle \mathbf {v} '=\mathbf {v} +\mathbf {V} }
Equivalent accelerations a ′ = a {\displaystyle \mathbf {a} '=\mathbf {a} }
a ′ = a + A {\displaystyle \mathbf {a} '=\mathbf {a} +\mathbf {A} }
Apparent/fictitious forces F ′ = F − F a p p {\displaystyle \mathbf {F} '=\mathbf {F} -\mathbf {F} _{\mathrm {app} }}
Ω = Constant relative angular velocity between two frames F and F'. Λ = (Variable) relative angular acceleration between two accelerating frames F and F'.
θ ′ = θ + Ω t {\displaystyle \theta '=\theta +\Omega t} Relative velocity ω ′ = ω + Ω {\displaystyle {\boldsymbol {\omega }}'={\boldsymbol {\omega }}+{\boldsymbol {\Omega }}}
Equivalent accelerations α ′ = α {\displaystyle {\boldsymbol {\alpha }}'={\boldsymbol {\alpha }}}
α ′ = α + Λ {\displaystyle {\boldsymbol {\alpha }}'={\boldsymbol {\alpha }}+{\boldsymbol {\Lambda }}}
Apparent/fictitious torques τ ′ = τ − τ a p p {\displaystyle {\boldsymbol {\tau }}'={\boldsymbol {\tau }}-{\boldsymbol {\tau }}_{\mathrm {app} }}
d T ′ d t = d T d t − Ω × T {\displaystyle {\frac {{\rm {d}}\mathbf {T} '}{{\rm {d}}t}}={\frac {{\rm {d}}\mathbf {T} }{{\rm {d}}t}}-{\boldsymbol {\Omega }}\times \mathbf {T} }
SHM, DHM, SHO, and DHO refer to simple harmonic motion, damped harmonic motion, simple harmonic oscillator and damped harmonic oscillator respectively.
Solution: x = A sin ( ω t + ϕ ) {\displaystyle x=A\sin \left(\omega t+\phi \right)}
Solution: θ = Θ sin ( ω t + ϕ ) {\displaystyle \theta =\Theta \sin \left(\omega t+\phi \right)}
Solution (see below for ω' ): x = A e − b t / 2 m cos ( ω ′ ) {\displaystyle x=Ae^{-bt/2m}\cos \left(\omega '\right)}
Resonant frequency: ω r e s = ω 2 − ( b 4 m ) 2 {\displaystyle \omega _{\mathrm {res} }={\sqrt {\omega ^{2}-\left({\frac {b}{4m}}\right)^{2}}}}
Damping rate: γ = b / m {\displaystyle \gamma =b/m}
Expected lifetime of excitation: τ = 1 / γ {\displaystyle \tau =1/\gamma }
Solution: θ = Θ e − κ t / 2 m cos ( ω ) {\displaystyle \theta =\Theta e^{-\kappa t/2m}\cos \left(\omega \right)}
Resonant frequency: ω r e s = ω 2 − ( κ 4 m ) 2 {\displaystyle \omega _{\mathrm {res} }={\sqrt {\omega ^{2}-\left({\frac {\kappa }{4m}}\right)^{2}}}}
Damping rate: γ = κ / m {\displaystyle \gamma =\kappa /m}
Expected lifetime of excitation: τ = 1 / γ {\displaystyle \tau =1/\gamma }
ω = g L {\displaystyle \omega ={\sqrt {\frac {g}{L}}}}
Exact value can be shown to be: ω = g L [ 1 + ∑ k = 1 ∞ ∏ n = 1 k ( 2 n − 1 ) ∏ n = 1 m ( 2 n ) sin 2 n Θ ] {\displaystyle \omega ={\sqrt {\frac {g}{L}}}\left[1+\sum _{k=1}^{\infty }{\frac {\prod _{n=1}^{k}\left(2n-1\right)}{\prod _{n=1}^{m}\left(2n\right)}}\sin ^{2n}\Theta \right]}
U = m 2 ( x ) 2 = m ( ω A ) 2 2 cos 2 ( ω t + ϕ ) {\displaystyle U={\frac {m}{2}}\left(x\right)^{2}={\frac {m\left(\omega A\right)^{2}}{2}}\cos ^{2}(\omega t+\phi )} Maximum value at x = A : U m a x = m 2 ( ω A ) 2 {\displaystyle U_{\mathrm {max} }={\frac {m}{2}}\left(\omega A\right)^{2}}
Kinetic energy T = ω 2 m 2 ( d x d t ) 2 = m ( ω A ) 2 2 sin 2 ( ω t + ϕ ) {\displaystyle T={\frac {\omega ^{2}m}{2}}\left({\frac {\mathrm {d} x}{\mathrm {d} t}}\right)^{2}={\frac {m\left(\omega A\right)^{2}}{2}}\sin ^{2}\left(\omega t+\phi \right)}
Total energy E = T + U {\displaystyle E=T+U} | https://en.wikipedia.org/wiki/List_of_equations_in_classical_mechanics |
This article summarizes equations in the theory of fluid mechanics .
Here t ^ {\displaystyle \mathbf {\hat {t}} \,\!} is a unit vector in the direction of the flow/current/flux.
F b = − ρ f V i m m g = − F g {\displaystyle \mathbf {F} _{\mathrm {b} }=-\rho _{f}V_{\mathrm {imm} }\mathbf {g} =-\mathbf {F} _{\mathrm {g} }\,\!}
Apparent weight W a p p = W − F b {\displaystyle \mathbf {W} _{\mathrm {app} }=\mathbf {W} -\mathbf {F} _{\mathrm {b} }\,\!}
∂ ρ u ∂ t + ∇ ⋅ ( u ⊗ ( ρ u ) ) + ∇ p = 0 {\displaystyle {\frac {\partial \rho {\mathbf {u} }}{\partial t}}+\nabla \cdot \left(\mathbf {u} \otimes \left(\rho \mathbf {u} \right)\right)+\nabla p=0\,\!} ∂ E ∂ t + ∇ ⋅ ( u ( E + p ) ) = 0 {\displaystyle {\frac {\partial E}{\partial t}}+\nabla \cdot \left(\mathbf {u} \left(E+p\right)\right)=0\,\!} E = ρ ( U + 1 2 u 2 ) {\displaystyle E=\rho \left(U+{\frac {1}{2}}\mathbf {u} ^{2}\right)\,\!} | https://en.wikipedia.org/wiki/List_of_equations_in_fluid_mechanics |
This article summarizes equations in the theory of gravitation .
A common misconception occurs between centre of mass and centre of gravity . They are defined in similar ways but are not exactly the same quantity. Centre of mass is the mathematical description of placing all the mass in the region considered to one position, centre of gravity is a real physical quantity, the point of a body where the gravitational force acts. They are equal if and only if the external gravitational field is uniform.
Centre of gravity for a set of discrete masses: r c o g = 1 M | g ( r i ) | ∑ i m i | g ( r i ) | = 1 M | g ( r c o g ) | ∑ i r i m i | g ( r i ) | {\displaystyle {\begin{aligned}\mathbf {r} _{\mathrm {cog} }&={\frac {1}{M\left|\mathbf {g} \left(\mathbf {r} _{i}\right)\right|}}\sum _{i}\mathbf {m} _{i}\left|\mathbf {g} \left(\mathbf {r} _{i}\right)\right|\\&={\frac {1}{M\left|\mathbf {g} \left(\mathbf {r} _{\mathrm {cog} }\right)\right|}}\sum _{i}\mathbf {r} _{i}m_{i}\left|\mathbf {g} \left(\mathbf {r} _{i}\right)\right|\end{aligned}}\,\!}
Centre of gravity for a continuum of mass: r c o g = 1 M | g ( r c o g ) | ∫ | g ( r ) | d m = 1 M | g ( r c o g ) | ∫ r | g ( r ) | d n m = 1 M | g ( r c o g ) | ∫ r ρ n | g ( r ) | d n x {\displaystyle {\begin{aligned}\mathbf {r} _{\mathrm {cog} }&={\frac {1}{M\left|\mathbf {g} \left(\mathbf {r} _{\mathrm {cog} }\right)\right|}}\int \left|\mathbf {g} \left(\mathbf {r} \right)\right|\mathrm {d} \mathbf {m} \\&={\frac {1}{M\left|\mathbf {g} \left(\mathbf {r} _{\mathrm {cog} }\right)\right|}}\int \mathbf {r} \left|\mathbf {g} \left(\mathbf {r} \right)\right|\mathrm {d} ^{n}m\\&={\frac {1}{M\left|\mathbf {g} \left(\mathbf {r} _{\mathrm {cog} }\right)\right|}}\int \mathbf {r} \rho _{n}\left|\mathbf {g} \left(\mathbf {r} \right)\right|\mathrm {d} ^{n}x\end{aligned}}\,\!}
In the weak-field and slow motion limit of general relativity, the phenomenon of gravitoelectromagnetism (in short "GEM") occurs, creating a parallel between gravitation and electromagnetism . The gravitational field is the analogue of the electric field , while the gravitomagnetic field , which results from circulations of masses due to their angular momentum , is the analogue of the magnetic field.
It can be shown that a uniform spherically symmetric mass distribution generates an equivalent gravitational field to a point mass, so all formulae for point masses apply to bodies which can be modelled in this way.
Δ U = − ∫ C g ⋅ d r {\displaystyle \Delta U=-\int _{C}\mathbf {g} \cdot d\mathbf {r} \,\!}
U = ∫ V n d m ⋅ g {\displaystyle U=\int _{V_{n}}\mathrm {d} \mathbf {m} \cdot \mathbf {g} \,\!}
General classical equations. | https://en.wikipedia.org/wiki/List_of_equations_in_gravitation |
This article summarizes equations in the theory of nuclear physics and particle physics .
(common name/s)
N 0 = Initial number of atoms at time t = 0 N D = Number of atoms decayed at time t
t → t + T 1 / 2 {\displaystyle t\rightarrow t+T_{1/2}\,\!} N → N / 2 {\displaystyle N\rightarrow N/2\,\!}
Q = radiation quality factor (dimensionless)
W j = weighting factors corresponding to radiosensitivities of matter (dimensionless)
∑ j W j = 1 {\displaystyle \sum _{j}W_{j}=1\,\!}
hence (approximately)
d N d t = − λ N {\displaystyle {\frac {\mathrm {d} N}{\mathrm {d} t}}=-\lambda N}
N = N 0 e − λ t {\displaystyle N=N_{0}e^{-\lambda t}\,\!}
The following apply for the nuclear reaction:
in the centre of mass frame , where a and b are the initial species about to collide, c is the final species, and R is the resonant state .
σ ( E ) = π g k 2 Γ a b Γ c ( E − E 0 ) 2 + Γ 2 / 4 {\displaystyle \sigma (E)={\frac {\pi g}{k^{2}}}{\frac {\Gamma _{ab}\Gamma _{c}}{(E-E_{0})^{2}+\Gamma ^{2}/4}}}
Spin factor:
g = 2 J + 1 ( 2 s a + 1 ) ( 2 s b + 1 ) {\displaystyle g={\frac {2J+1}{(2s_{a}+1)(2s_{b}+1)}}}
Total width:
Γ = Γ a b + Γ c {\displaystyle \Gamma =\Gamma _{ab}+\Gamma _{c}}
Resonance lifetime:
τ = ℏ / Γ {\displaystyle \tau =\hbar /\Gamma }
d σ d Ω = | 2 μ ℏ 2 ∫ 0 ∞ sin ( Δ k r ) Δ k r V ( r ) r 2 d r | 2 {\displaystyle {\frac {d\sigma }{d\Omega }}=\left|{\frac {2\mu }{\hbar ^{2}}}\int _{0}^{\infty }{\frac {\sin(\Delta kr)}{\Delta kr}}V(r)r^{2}dr\right|^{2}}
d σ d Ω = ( α 4 E ) [ csc 4 χ 2 + sec 4 χ 2 + A cos ( α ℏ ν ln tan 2 χ 2 ) sin 2 χ 2 cos χ 2 ] 2 {\displaystyle {\frac {d\sigma }{d\Omega }}=\left({\frac {\alpha }{4E}}\right)\left[\csc ^{4}{\frac {\chi }{2}}+\sec ^{4}{\frac {\chi }{2}}+{\frac {A\cos \left({\frac {\alpha }{\hbar \nu }}\ln \tan ^{2}{\frac {\chi }{2}}\right)}{\sin ^{2}{\frac {\chi }{2}}\cos {\frac {\chi }{2}}}}\right]^{2}}
Scattering potential energy (α = constant):
V = − α / r {\displaystyle V=-\alpha /r}
d σ d Ω = ( 1 n ) d N d Ω = ( α 4 E ) 2 csc 4 χ 2 {\displaystyle {\frac {d\sigma }{d\Omega }}=\left({\frac {1}{n}}\right){\frac {dN}{d\Omega }}=\left({\frac {\alpha }{4E}}\right)^{2}\csc ^{4}{\frac {\chi }{2}}}
These equations need to be refined such that the notation is defined as has been done for the previous sets of equations. | https://en.wikipedia.org/wiki/List_of_equations_in_nuclear_and_particle_physics |
This article summarizes equations in the theory of quantum mechanics .
A fundamental physical constant occurring in quantum mechanics is the Planck constant , h . A common abbreviation is ħ = h /2 π , also known as the reduced Planck constant or Dirac constant .
j = − i ℏ 2 m ( Ψ ∗ ∇ Ψ − Ψ ∇ Ψ ∗ ) = ℏ m Im ( Ψ ∗ ∇ Ψ ) = Re ( Ψ ∗ ℏ i m ∇ Ψ ) {\displaystyle {\begin{aligned}\mathbf {j} &={\frac {-i\hbar }{2m}}\left(\Psi ^{*}\nabla \Psi -\Psi \nabla \Psi ^{*}\right)\\&={\frac {\hbar }{m}}\operatorname {Im} \left(\Psi ^{*}\nabla \Psi \right)=\operatorname {Re} \left(\Psi ^{*}{\frac {\hbar }{im}}\nabla \Psi \right)\end{aligned}}}
star * is complex conjugate
The general form of wavefunction for a system of particles, each with position r i and z-component of spin s z i . Sums are over the discrete variable s z , integrals over continuous positions r .
For clarity and brevity, the coordinates are collected into tuples, the indices label the particles (which cannot be done physically, but is mathematically necessary). Following are general mathematical results, used in calculations.
Ψ = Ψ ( r , s z , t ) {\displaystyle \Psi =\Psi \left(\mathbf {r} ,\mathbf {s_{z}} ,t\right)}
in bra–ket notation : | Ψ ⟩ = ∑ s z 1 ∑ s z 2 ⋯ ∑ s z N ∫ V 1 ∫ V 2 ⋯ ∫ V N d r 1 d r 2 ⋯ d r N Ψ | r , s z ⟩ {\displaystyle |\Psi \rangle =\sum _{s_{z1}}\sum _{s_{z2}}\cdots \sum _{s_{zN}}\int _{V_{1}}\int _{V_{2}}\cdots \int _{V_{N}}\mathrm {d} \mathbf {r} _{1}\mathrm {d} \mathbf {r} _{2}\cdots \mathrm {d} \mathbf {r} _{N}\Psi |\mathbf {r} ,\mathbf {s_{z}} \rangle }
for non-interacting particles:
Ψ = ∏ n = 1 N Ψ ( r n , s z n , t ) {\displaystyle \Psi =\prod _{n=1}^{N}\Psi \left(\mathbf {r} _{n},s_{zn},t\right)}
i ℏ ∂ ∂ t Ψ = H ^ Ψ {\displaystyle i\hbar {\frac {\partial }{\partial t}}\Psi ={\hat {H}}\Psi }
Time-independent case: H ^ Ψ = E Ψ {\displaystyle {\hat {H}}\Psi =E\Psi }
of a particle.
For momentum and position;
m d d t ⟨ r ⟩ = ⟨ p ⟩ {\displaystyle m{\frac {d}{dt}}\langle \mathbf {r} \rangle =\langle \mathbf {p} \rangle }
d d t ⟨ p ⟩ = − ⟨ ∇ V ⟩ {\displaystyle {\frac {d}{dt}}\langle \mathbf {p} \rangle =-\langle \nabla V\rangle }
Summarized below are the various forms the Hamiltonian takes, with the corresponding Schrödinger equations and forms of wavefunction solutions. Notice in the case of one spatial dimension, for one particle, the partial derivative reduces to an ordinary derivative .
where the position of particle n is x n .
There is a further restriction — the solution must not grow at infinity, so that it has either a finite L 2 -norm (if it is a bound state ) or a slowly diverging norm (if it is part of a continuum ): [ 1 ] ‖ ψ ‖ 2 = ∫ | ψ ( x ) | 2 d x . {\displaystyle \|\psi \|^{2}=\int |\psi (x)|^{2}\,dx.\,}
for non-interacting particles
Ψ = e − i E t / ℏ ∏ n = 1 N ψ ( x n ) , V ( x 1 , x 2 , ⋯ x N ) = ∑ n = 1 N V ( x n ) . {\displaystyle \Psi =e^{-i{Et/\hbar }}\prod _{n=1}^{N}\psi (x_{n})\,,\quad V(x_{1},x_{2},\cdots x_{N})=\sum _{n=1}^{N}V(x_{n})\,.}
where the position of the particle is r = ( x, y, z ).
where the position of particle n is r n = ( x n , y n , z n ), and the Laplacian for particle n using the corresponding position coordinates is
∇ n 2 = ∂ 2 ∂ x n 2 + ∂ 2 ∂ y n 2 + ∂ 2 ∂ z n 2 {\displaystyle \nabla _{n}^{2}={\frac {\partial ^{2}}{{\partial x_{n}}^{2}}}+{\frac {\partial ^{2}}{{\partial y_{n}}^{2}}}+{\frac {\partial ^{2}}{{\partial z_{n}}^{2}}}}
for non-interacting particles
Ψ = e − i E t / ℏ ∏ n = 1 N ψ ( r n ) , V ( r 1 , r 2 , ⋯ r N ) = ∑ n = 1 N V ( r n ) {\displaystyle \Psi =e^{-i{Et/\hbar }}\prod _{n=1}^{N}\psi (\mathbf {r} _{n})\,,\quad V(\mathbf {r} _{1},\mathbf {r} _{2},\cdots \mathbf {r} _{N})=\sum _{n=1}^{N}V(\mathbf {r} _{n})}
Again, summarized below are the various forms the Hamiltonian takes, with the corresponding Schrödinger equations and forms of solutions.
where the position of particle n is x n .
This last equation is in a very high dimension, [ 2 ] so the solutions are not easy to visualize.
The De Broglie relations give the relation between them:
ϕ = h f 0 {\displaystyle \phi =hf_{0}\,\!}
The De Broglie relations give:
p = h f / c = h / λ {\displaystyle p=hf/c=h/\lambda \,\!}
σ ( x ) σ ( p ) ≥ ℏ 2 {\displaystyle \sigma (x)\sigma (p)\geq {\frac {\hbar }{2}}\,\!}
Energy-time σ ( E ) σ ( t ) ≥ ℏ 2 {\displaystyle \sigma (E)\sigma (t)\geq {\frac {\hbar }{2}}\,\!}
Number-phase σ ( n ) σ ( ϕ ) ≥ ℏ 2 {\displaystyle \sigma (n)\sigma (\phi )\geq {\frac {\hbar }{2}}\,\!}
σ ( A ) 2 = ⟨ ( A − ⟨ A ⟩ ) 2 ⟩ = ⟨ A 2 ⟩ − ⟨ A ⟩ 2 {\displaystyle {\begin{aligned}\sigma (A)^{2}&=\langle (A-\langle A\rangle )^{2}\rangle \\&=\langle A^{2}\rangle -\langle A\rangle ^{2}\end{aligned}}}
where
Spin: ‖ s ‖ = s ( s + 1 ) ℏ m s ∈ { − s , − s + 1 ⋯ s − 1 , s } {\displaystyle {\begin{aligned}&\Vert \mathbf {s} \Vert ={\sqrt {s\,(s+1)}}\,\hbar \\&m_{s}\in \{-s,-s+1\cdots s-1,s\}\\\end{aligned}}\,\!}
Orbital: ℓ ∈ { 0 ⋯ n − 1 } m ℓ ∈ { − ℓ , − ℓ + 1 ⋯ ℓ − 1 , ℓ } {\displaystyle {\begin{aligned}&\ell \in \{0\cdots n-1\}\\&m_{\ell }\in \{-\ell ,-\ell +1\cdots \ell -1,\ell \}\\\end{aligned}}\,\!}
Total: j = ℓ + s m j ∈ { | ℓ − s | , | ℓ − s | + 1 ⋯ | ℓ + s | − 1 , | ℓ + s | } {\displaystyle {\begin{aligned}&j=\ell +s\\&m_{j}\in \{|\ell -s|,|\ell -s|+1\cdots |\ell +s|-1,|\ell +s|\}\\\end{aligned}}\,\!}
| S | = ℏ s ( s + 1 ) {\displaystyle |\mathbf {S} |=\hbar {\sqrt {s(s+1)}}\,\!}
Orbital magnitude: | L | = ℏ ℓ ( ℓ + 1 ) {\displaystyle |\mathbf {L} |=\hbar {\sqrt {\ell (\ell +1)}}\,\!}
Total magnitude: J = L + S {\displaystyle \mathbf {J} =\mathbf {L} +\mathbf {S} \,\!}
| J | = ℏ j ( j + 1 ) {\displaystyle |\mathbf {J} |=\hbar {\sqrt {j(j+1)}}\,\!}
S z = m s ℏ {\displaystyle S_{z}=m_{s}\hbar \,\!}
Orbital: L z = m ℓ ℏ {\displaystyle L_{z}=m_{\ell }\hbar \,\!}
In what follows, B is an applied external magnetic field and the quantum numbers above are used.
z-component: μ ℓ , z = − m ℓ μ B {\displaystyle \mu _{\ell ,z}=-m_{\ell }\mu _{B}\,\!}
z-component: μ s , z = − e S z / m e = g s e S z / 2 m e {\displaystyle \mu _{s,z}=-eS_{z}/m_{e}=g_{s}eS_{z}/2m_{e}\,\!} | https://en.wikipedia.org/wiki/List_of_equations_in_quantum_mechanics |
This article summarizes equations in the theory of waves .
A wave can be longitudinal where the oscillations are parallel (or antiparallel) to the propagation direction, or transverse where the oscillations are perpendicular to the propagation direction. These oscillations are characterized by a periodically time-varying displacement in the parallel or perpendicular direction, and so the instantaneous velocity and acceleration are also periodic and time varying in these directions. (the apparent motion of the wave due to the successive oscillations of particles or fields about their equilibrium positions) propagates at the phase and group velocities parallel or antiparallel to the propagation direction, which is common to longitudinal and transverse waves. Below oscillatory displacement, velocity and acceleration refer to the kinematics in the oscillating directions of the wave - transverse or longitudinal (mathematical description is identical), the group and phase velocities are separate.
A = A e ^ ∥ {\displaystyle \mathbf {A} =A\mathbf {\hat {e}} _{\parallel }\,\!} for longitudinal waves, A = A e ^ ⊥ {\displaystyle \mathbf {A} =A\mathbf {\hat {e}} _{\bot }\,\!} for transverse waves.
r ≡ r e ^ ∥ ≡ d − r 0 {\displaystyle \mathbf {r} \equiv r\mathbf {\hat {e}} _{\parallel }\equiv \mathbf {d} -\mathbf {r} _{0}\,\!}
λ = d r / d N {\displaystyle \lambda =\mathrm {d} r/\mathrm {d} N\,\!}
For non-FM waves this reduces to: λ = Δ r / Δ N {\displaystyle \lambda =\Delta r/\Delta N\,\!}
k = ( 2 π / λ ) e ^ ∠ {\displaystyle \mathbf {k} =\left(2\pi /\lambda \right)\mathbf {\hat {e}} _{\angle }\,\!} k = ( 1 / λ ) e ^ ∠ {\displaystyle \mathbf {k} =\left(1/\lambda \right)\mathbf {\hat {e}} _{\angle }\,\!}
f = d N / d t {\displaystyle f=\mathrm {d} N/\mathrm {d} t\,\!}
For non-FM waves this reduces to: f = Δ N / Δ t {\displaystyle f=\Delta N/\Delta t\,\!}
In practice N is set to 1 cycle and t = T = time period for 1 cycle, to obtain the more useful relation: f = 1 / T {\displaystyle f=1/T\,\!}
v = e ^ ∥ ( ∂ A / ∂ t ) {\displaystyle \mathbf {v} =\mathbf {\hat {e}} _{\parallel }\left(\partial A/\partial t\right)\,\!}
Transverse waves: v = e ^ ⊥ ( ∂ A / ∂ t ) {\displaystyle \mathbf {v} =\mathbf {\hat {e}} _{\bot }\left(\partial A/\partial t\right)\,\!}
a = e ^ ∥ ( ∂ 2 A / ∂ t 2 ) {\displaystyle \mathbf {a} =\mathbf {\hat {e}} _{\parallel }\left(\partial ^{2}A/\partial t^{2}\right)\,\!}
Transverse waves: a = e ^ ⊥ ( ∂ 2 A / ∂ t 2 ) {\displaystyle \mathbf {a} =\mathbf {\hat {e}} _{\bot }\left(\partial ^{2}A/\partial t^{2}\right)\,\!}
v p = e ^ ∥ ( Δ r / Δ t ) {\displaystyle \mathbf {v} _{\mathrm {p} }=\mathbf {\hat {e}} _{\parallel }\left(\Delta r/\Delta t\right)\,\!}
In practice reduces to the useful form: v p = λ f e ^ ∥ = ( ω / k ) e ^ ∥ {\displaystyle \mathbf {v} _{\mathrm {p} }=\lambda f\mathbf {\hat {e}} _{\parallel }=\left(\omega /k\right)\mathbf {\hat {e}} _{\parallel }\,\!}
Physically; upper sign: wave propagation in + r direction lower sign: wave propagation in − r direction
Phase angle can lag if: ϕ > 0 or lead if: ϕ < 0.
Relation between space, time, angle analogues used to describe the phase:
Δ r λ = Δ t T = ϕ 2 π {\displaystyle {\frac {\Delta r}{\lambda }}={\frac {\Delta t}{T}}={\frac {\phi }{2\pi }}\,\!}
A = carrier amplitude A m = peak amplitude of a component in the modulating signal
Δ f = max. deviation of the instantaneous frequency from the carrier frequency f m = peak frequency of a component in the modulating signal
Δ ϕ = peak phase deviation
v = speed of sound, ρ = volume density of medium
S = surface area
In what follows n, m are any integers ( Z = set of integers ); n , m ∈ Z {\displaystyle n,m\in \mathbf {Z} \,\!} .
I = P / A = ρ v ω 2 s m 2 / 2 {\displaystyle I=P/A=\rho v\omega ^{2}s_{m}^{2}/2\,\!}
upper signs indicate relative approach, lower signs indicate relative recession.
s = [ 2 s 0 cos ( ω ′ t ) ] cos ( ω t ) {\displaystyle s=\left[2s_{0}\cos \left(\omega 't\right)\right]\cos \left(\omega t\right)\,\!}
Sound displacement function s = s 0 cos ( k r − ω t ) {\displaystyle s=s_{0}\cos(kr-\omega t)\,\!}
Sound pressure-variation p = p 0 sin ( k r − ω t ) {\displaystyle p=p_{0}\sin(kr-\omega t)\,\!}
Gravitational radiation for two orbiting bodies in the low-speed limit. [ 1 ]
Constructive interference n = λ Δ x {\displaystyle n={\frac {\lambda }{\Delta x}}\,\!}
Destructive interference n + 1 2 = λ Δ x {\displaystyle n+{\frac {1}{2}}={\frac {\lambda }{\Delta x}}\,\!}
A common misconception occurs between phase velocity and group velocity (analogous to centres of mass and gravity). They happen to be equal in non-dispersive media. In dispersive media the phase velocity is not necessarily the same as the group velocity. The phase velocity varies with frequency.
Intuitively the wave envelope is the "global profile" of the wave, which "contains" changing "local profiles inside the global profile". Each propagates at generally different speeds determined by the important function called the dispersion relation . The use of the explicit form ω ( k ) is standard, since the phase velocity ω / k and the group velocity d ω /d k usually have convenient representations by this function.
D ( ω , k ) = 0 {\displaystyle D\left(\omega ,k\right)=0}
Explicit form ω = ω ( k ) {\displaystyle \omega =\omega \left(k\right)}
Complex amplitude of wave n A n = | A n | e i ( k n ⋅ r − ω n t + ϕ n ) {\displaystyle A_{n}=\left|A_{n}\right|e^{i\left(\mathbf {k} _{\mathrm {n} }\cdot \mathbf {r} -\omega _{n}t+\phi _{n}\right)}\,\!}
Resultant complex amplitude of all N waves A = ∑ n = 1 N A n {\displaystyle A=\sum _{n=1}^{N}A_{n}\,\!}
Modulus of amplitude A = A A ∗ = ∑ n = 1 N ∑ m = 1 N | A n | | A m | cos [ ( k n − k m ) ⋅ r + ( ω n − ω m ) t + ( ϕ n − ϕ m ) ] {\displaystyle A={\sqrt {AA^{*}}}={\sqrt {\sum _{n=1}^{N}\sum _{m=1}^{N}\left|A_{n}\right|\left|A_{m}\right|\cos \left[\left(\mathbf {k} _{n}-\mathbf {k} _{m}\right)\cdot \mathbf {r} +\left(\omega _{n}-\omega _{m}\right)t+\left(\phi _{n}-\phi _{m}\right)\right]}}\,\!}
The transverse displacements are simply the real parts of the complex amplitudes.
1-dimensional corollaries for two sinusoidal waves
The following may be deduced by applying the principle of superposition to two sinusoidal waves, using trigonometric identities. The angle addition and sum-to-product trigonometric formulae are useful; in more advanced work complex numbers and fourier series and transforms are used. | https://en.wikipedia.org/wiki/List_of_equations_in_wave_theory |
Essential oils are volatile and liquid aroma compounds from natural sources, usually plants. They are not oils in a strict sense, but often share with oils a poor solubility in water. Essential oils often have an odor and are therefore used in food flavoring and perfumery . They are usually prepared by fragrance extraction techniques (such as distillation , cold pressing , or Solvent extraction ). Essential oils are distinguished from aroma oils (essential oils and aroma compounds in an oily solvent ), infusions in a vegetable oil, absolutes , and concretes . Typically, essential oils are highly complex mixtures of often hundreds of individual aroma compounds. | https://en.wikipedia.org/wiki/List_of_essential_oils |
In chemistry , an ester is a compound derived from an acid (organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group ( −OH ) of that acid is replaced by an organyl group ( −R ). Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well (i.e. esters of acidic − S H , − Se H , − Te H , − Po H and − Lv H groups). According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well (e.g. amides ), but not according to the IUPAC . [ 1 ]
An example of an ester formation is the substitution reaction between a carboxylic acid ( R−C(=O)−OH ) and an alcohol (R'OH), forming an ester ( R−C(=O)−O−R' ), where R and R′ are organyl groups, or H in the case of esters of formic acid . Glycerides , which are fatty acid esters of glycerol , are important esters in biology, being one of the main classes of lipids , and making up the bulk of animal fats and vegetable oils. Esters of carboxylic acids with low molecular weight are commonly used as fragrances and found in essential oils and pheromones . Phosphoesters form the backbone of DNA molecules. Nitrate esters , such as nitroglycerin , are known for their explosive properties, while polyesters are important plastics , with monomers linked by ester moieties . Esters of carboxylic acids usually have a sweet smell and are considered high-quality solvents for a broad array of plastics, plasticizers , resins , and lacquers . [ 2 ] They are also one of the largest classes of synthetic lubricants on the commercial market. [ 3 ]
Many esters of carboxylic acid have distinctive fruit-like odors, and many occur naturally in fruits and the essential oils of plants. This has also led to their common use in artificial flavorings and fragrances which aim to mimic those odors.
Lactones are a specific class cyclic carboxylic esters that are formed through intramolecular esterification . | https://en.wikipedia.org/wiki/List_of_esters |
This is a list of steroidal estrogens or derivatives of estradiol , estrone , and estriol . Most esters of these estrogens are not included in this list; for esters, see here instead.
? = Chemical names that are unverified. | https://en.wikipedia.org/wiki/List_of_estrogens |
This is a list of accidental explosions and facts about each one, grouped by the time of their occurrence. It does not include explosions caused by terrorist attacks or arson, as well as intentional explosions for civil or military purposes. It may still include entries for which the cause is unclear or still under investigation.
For a list based on power or death toll see largest artificial non-nuclear explosions or the explosions section of list of accidents and disasters by death toll . This list also contains notable explosions that would not qualify for the articles mentioned above and is more detailed, especially for the latest centuries. | https://en.wikipedia.org/wiki/List_of_explosions |
This is a list of notable custom software projects which have significantly failed to achieve some or all of their objectives, either temporarily or permanently, and/or have suffered from significant cost overruns .
Note that failed projects, and projects running over budget, are not necessarily the sole fault of the employees or businesses creating the software. In some cases, problems may be due partly to problems with the purchasing organisation, including poor requirements , over-ambitious requirements, unnecessary requirements, poor contract drafting, poor contract management, poor end-user training , or poor operational management.
Because software, unlike a major civil engineering construction project, is often easy and cheap to change after it has been constructed, a piece of custom software that fails to deliver on its objectives may sometimes be modified over time in such a way that it later succeeds—and/or business processes or end-user mindsets may change to accommodate the software. However, sometimes, for various reasons, neither approach succeeds (or is even tried), and this may be considered as another level of failure—a permanent failure.
Until the significant problems with these projects are resolved, or the projects cancelled, it is not yet possible to classify them into one of the above categories. | https://en.wikipedia.org/wiki/List_of_failed_and_overbudget_custom_software_projects |
This is a list of fast radio bursts . Items are listed here if information about the fast radio burst has been published. Although there could be thousands of detectable events per day, only detected ones are listed. | https://en.wikipedia.org/wiki/List_of_fast_radio_bursts |
Windows 10 is a version of Windows NT and the successor of Windows 8.1 . Some features of the operating system were removed in comparison to Windows 8 and Windows 8.1, and further changes in features offered have occurred within subsequent feature updates to Windows 10. Following is a list of these.
Microsoft has published a list of Windows features that are no longer actively developed. Microsoft states that these features may potentially be removed in future updates to Windows 10. [ 51 ] | https://en.wikipedia.org/wiki/List_of_features_removed_in_Windows_10 |
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