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Leaves
Leaves are palmately compound in mature trees, but seedlings and regenerating shoots may have simple leaves. The transition to compound leaves comes with age and may be gradual. Leaves have 5–11 leaflets, with the largest ones in the middle and may be stalkless or with short petioles. Leaflets may have toothed o... | Adansonia | Wikipedia | 238 | 563290 | https://en.wikipedia.org/wiki/Adansonia | Biology and health sciences | Others | null |
Flowers may remain attached to the trees for several days, but the reproductive phase is very short, with pollen shed during the first night and stigmas shriveled by the morning. The flower is made up of an outer 5-lobed calyx, and an inner ring of petals set around a fused tube of stamens. The outer lobes of the calyx... | Adansonia | Wikipedia | 455 | 563290 | https://en.wikipedia.org/wiki/Adansonia | Biology and health sciences | Others | null |
Taxonomy
The earliest written reports of baobab are from a 14th-century travelogue by the Arab traveler Ibn Battuta. The first botanical description was in the De medicina Aegyptiorum by Prospero Alpini (1592), looking at fruits that he observed in Egypt from an unknown source. They were called Bahobab, possibly from t... | Adansonia | Wikipedia | 185 | 563290 | https://en.wikipedia.org/wiki/Adansonia | Biology and health sciences | Others | null |
The genus Adansonia is in the subfamily Bombacoideae, within the family Malvaceae in the order Malvales. The subfamily Bombacoideae was previously treated as the Bombacaceae family but it is no longer recognized at the rank of family by the Angiosperm Phylogeny Group I 1998, II 2003 or the Kubitzki system 2003. There a... | Adansonia | Wikipedia | 339 | 563290 | https://en.wikipedia.org/wiki/Adansonia | Biology and health sciences | Others | null |
, there are eight recognized species of Adansonia, with six endemic to Madagascar, one native to mainland Africa and the Arabian Peninsula, and one native to Australia. The mainland African species (Adansonia digitata) also occurs on Madagascar, but it is not a native of that island. Baobabs were introduced in ancient ... | Adansonia | Wikipedia | 491 | 563290 | https://en.wikipedia.org/wiki/Adansonia | Biology and health sciences | Others | null |
Radiocarbon dating has provided data on a few individuals of A. digitata. The Panke baobab in Zimbabwe was some 2,450 years old when it died in 2011, making it the oldest angiosperm ever documented, and two other trees—Dorslandboom in Namibia and Glencoe in South Africa—were estimated to be approximately 2,000 years ol... | Adansonia | Wikipedia | 489 | 563290 | https://en.wikipedia.org/wiki/Adansonia | Biology and health sciences | Others | null |
In Angola, the dry fruit of A. digitata is usually boiled, and the broth is used for juices or as the base for a type of ice cream known as gelado de múcua. In Zimbabwe, the fruit of A. digitata is eaten fresh or the crushed crumbly pulp is stirred into porridge and drinks. In Tanzania, the dry pulp of A. digitata is a... | Adansonia | Wikipedia | 307 | 563290 | https://en.wikipedia.org/wiki/Adansonia | Biology and health sciences | Others | null |
A delimiter is a sequence of one or more characters for specifying the boundary between separate, independent regions in plain text, mathematical expressions or other data streams. An example of a delimiter is the comma character, which acts as a field delimiter in a sequence of comma-separated values. Another example ... | Delimiter | Wikipedia | 416 | 564276 | https://en.wikipedia.org/wiki/Delimiter | Technology | Programming languages | null |
An expression vector, otherwise known as an expression construct, is usually a plasmid or virus designed for gene expression in cells. The vector is used to introduce a specific gene into a target cell, and can commandeer the cell's mechanism for protein synthesis to produce the protein encoded by the gene. Expression... | Expression vector | Wikipedia | 505 | 564380 | https://en.wikipedia.org/wiki/Expression%20vector | Biology and health sciences | Molecular biology | Biology |
The promoter initiates the transcription and is therefore the point of control for the expression of the cloned gene. The promoters used in expression vector are normally inducible, meaning that protein synthesis is only initiated when required by the introduction of an inducer such as IPTG. Gene expression however may... | Expression vector | Wikipedia | 440 | 564380 | https://en.wikipedia.org/wiki/Expression%20vector | Biology and health sciences | Molecular biology | Biology |
The expression host of choice for the expression of many proteins is Escherichia coli as the production of heterologous protein in E. coli is relatively simple and convenient, as well as being rapid and cheap. A large number of E. coli expression plasmids are also available for a wide variety of needs. Other bacteria u... | Expression vector | Wikipedia | 476 | 564380 | https://en.wikipedia.org/wiki/Expression%20vector | Biology and health sciences | Molecular biology | Biology |
It is possible to simultaneously express two or more different proteins in E. coli using different plasmids. However, when 2 or more plasmids are used, each plasmid needs to use a different antibiotic selection as well as a different origin of replication, otherwise one of the plasmids may not be stably maintained. Man... | Expression vector | Wikipedia | 401 | 564380 | https://en.wikipedia.org/wiki/Expression%20vector | Biology and health sciences | Molecular biology | Biology |
Baculovirus
Baculovirus, a rod-shaped virus which infects insect cells, is used as the expression vector in this system. Insect cell lines derived from Lepidopterans (moths and butterflies), such as Spodoptera frugiperda, are used as host. A cell line derived from the cabbage looper is of particular interest, as it has... | Expression vector | Wikipedia | 503 | 564380 | https://en.wikipedia.org/wiki/Expression%20vector | Biology and health sciences | Molecular biology | Biology |
Mammalian
Mammalian expression vectors offer considerable advantages for the expression of mammalian proteins over bacterial expression systems - proper folding, post-translational modifications, and relevant enzymatic activity. It may also be more desirable than other eukaryotic non-mammalian systems whereby the prote... | Expression vector | Wikipedia | 471 | 564380 | https://en.wikipedia.org/wiki/Expression%20vector | Biology and health sciences | Molecular biology | Biology |
Laboratory use
Expression vector in an expression host is now the usual method used in laboratories to produce proteins for research. Most proteins are produced in E. coli, but for glycosylated proteins and those with disulphide bonds, yeast, baculovirus and mammalian systems may be used.
Production of peptide and pro... | Expression vector | Wikipedia | 460 | 564380 | https://en.wikipedia.org/wiki/Expression%20vector | Biology and health sciences | Molecular biology | Biology |
Transgenic animals have also been produced to study animal biochemical processes and human diseases, or used to produce pharmaceuticals and other proteins. They may also be engineered to have advantageous or useful traits. Green fluorescent protein is sometimes used as tags which results in animal that can fluoresce, a... | Expression vector | Wikipedia | 174 | 564380 | https://en.wikipedia.org/wiki/Expression%20vector | Biology and health sciences | Molecular biology | Biology |
A clock face is the part of an analog clock (or watch) that displays time through the use of a flat dial with reference marks, and revolving pointers turning on concentric shafts at the center, called hands. In its most basic, globally recognized form, the periphery of the dial is numbered 1 through 12 indicating the ... | Clock face | Wikipedia | 502 | 564384 | https://en.wikipedia.org/wiki/Clock%20face | Technology | Clocks | null |
The second, or sweep, hand moves relatively quickly, taking a full minute (sixty seconds) to make a complete rotation from 12 to 12. For every rotation of the second hand, the minute hand will move from one minute mark to the next.
The minute hand rotates more slowly around the dial. It takes one hour (sixty minutes) ... | Clock face | Wikipedia | 332 | 564384 | https://en.wikipedia.org/wiki/Clock%20face | Technology | Clocks | null |
Before the late 14th century, a fixed hand (often a carving literally shaped like a hand) indicated the hour by pointing to numbers on a rotating dial; after this time, the current convention of a rotating hand on a fixed dial was adopted. Minute hands (so named because they indicated the small, or minute, divisions of... | Clock face | Wikipedia | 497 | 564384 | https://en.wikipedia.org/wiki/Clock%20face | Technology | Clocks | null |
It is customary for modern advertisements to display clocks and watches set to approximately 10:10 or 1:50,
as this V-shaped arrangement roughly makes a smile, imitates a human figure with raised arms, and leaves the watch company's logo unobscured by the hands.
In the 1970s, German designer Tian Harlan invented the ... | Clock face | Wikipedia | 207 | 564384 | https://en.wikipedia.org/wiki/Clock%20face | Technology | Clocks | null |
The African buffalo (Syncerus caffer) is a large sub-Saharan African bovine. There are five subspecies that are recognized as valid by most authorities:
Syncerus caffer caffer, the Cape buffalo, is the nominotypical subspecies, as well as the largest, found in Southern and East Africa.
S. c. nanus, the forest buffal... | African buffalo | Wikipedia | 361 | 564971 | https://en.wikipedia.org/wiki/African%20buffalo | Biology and health sciences | Artiodactyla | null |
The African buffalo is a very robust species. Its shoulder height can range from and its head-and-body length can range from . The tail can range from long. Compared with other large bovids, it has a long but stocky body (the body length can exceed the wild water buffalo, which is heavier and taller) and short but th... | African buffalo | Wikipedia | 476 | 564971 | https://en.wikipedia.org/wiki/African%20buffalo | Biology and health sciences | Artiodactyla | null |
Ecology
The African buffalo is one of the most successful grazers in Africa. It lives in savannas, swamps and floodplains, as well as mopane grasslands, and the forests of the major mountains of Africa. This buffalo prefers a habitat with dense cover, such as reeds and thickets, but can also be found in open woodland. ... | African buffalo | Wikipedia | 169 | 564971 | https://en.wikipedia.org/wiki/African%20buffalo | Biology and health sciences | Artiodactyla | null |
Other than humans, African buffaloes have few predators and are capable of defending themselves against (and killing) lions. Lions kill and eat buffaloes regularly, and in some regions, the buffaloes are the lions' primary prey. It often takes several lions to bring down a single adult buffalo, and the entire pride may... | African buffalo | Wikipedia | 383 | 564971 | https://en.wikipedia.org/wiki/African%20buffalo | Biology and health sciences | Artiodactyla | null |
The African buffalo is susceptible to many diseases, including those shared with domestic cattle, such as bovine tuberculosis, corridor disease, and foot-and-mouth disease. As with many diseases, these problems remain dormant within a population as long as the health of the animals is good. These diseases do, however, ... | African buffalo | Wikipedia | 501 | 564971 | https://en.wikipedia.org/wiki/African%20buffalo | Biology and health sciences | Artiodactyla | null |
Adult bulls spar in play, dominance interactions, or actual fights. A bull approaches another, lowing, with his horns down, and waits for the other bull to do the same thing. When sparring, the bulls twist their horns from side to side. If the sparring is for play, the bull may rub his opponent's face and body during t... | African buffalo | Wikipedia | 446 | 564971 | https://en.wikipedia.org/wiki/African%20buffalo | Biology and health sciences | Artiodactyla | null |
Females reach sexual maturity at around five years of age while males are sexually matured at four to six. African buffaloes mate and give birth only during the rainy seasons. Birth peak takes place early in the season, while mating peaks later. A bull closely guards a cow that comes into heat, while keeping other bull... | African buffalo | Wikipedia | 496 | 564971 | https://en.wikipedia.org/wiki/African%20buffalo | Biology and health sciences | Artiodactyla | null |
In the past, numbers of African buffaloes suffered their most severe collapse during the great rinderpest epidemic of the 1890s, which, coupled with pleuro-pneumonia, caused mortalities as high as 95% among livestock and wild ungulates.
Being a member of the big five game group, a term used to describe the five most d... | African buffalo | Wikipedia | 365 | 564971 | https://en.wikipedia.org/wiki/African%20buffalo | Biology and health sciences | Artiodactyla | null |
The mesopelagic zone (Greek μέσον, middle), also known as the middle pelagic or twilight zone, is the part of the pelagic zone that lies between the photic epipelagic and the aphotic bathypelagic zones. It is defined by light, and begins at the depth where only 1% of incident light reaches and ends where there is no li... | Mesopelagic zone | Wikipedia | 377 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
The mesopelagic zone has some unique acoustic features. The Sound Fixing and Ranging (SOFAR) channel, where sound travels the slowest due to salinity and temperature variations, is located at the base of the mesopelagic zone at about 600–1,200m. It is a wave-guided zone where sound waves refract within the layer and pr... | Mesopelagic zone | Wikipedia | 427 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
In the mesopelagic zone, the biological pump is key to carbon cycling, as this zone is largely dominated by remineralization of particulate organic carbon (POC). When a fraction of POC is exported from the euphotic zone, an estimated 90% of that POC is respired in the mesopelagic zone. This is due to the microbial org... | Mesopelagic zone | Wikipedia | 386 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
Oxygen
Dissolved oxygen is a requirement for aerobic respiration, and while the surface ocean is usually oxygen-rich due to atmospheric gas exchange and photosynthesis, the mesopelagic zone is not in direct contact with the atmosphere, due to stratification at the base of the surface mixed layer. Organic matter is exp... | Mesopelagic zone | Wikipedia | 419 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
Although some light penetrates the mesopelagic zone, it is insufficient for photosynthesis. The biological community of the mesopelagic zone has adapted to a low-light environment. This is a very efficient ecosystem with many organisms recycling the organic matter sinking from the epipelagic zone resulting in very li... | Mesopelagic zone | Wikipedia | 444 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
Microbial biomass and diversity typically decline exponentially with depth in the mesopelagic zone, tracking the general decline of food from above. The community composition varies with depths in the mesopelagic as different organisms are evolved for varying light conditions. Microbial biomass in the mesopelagic is gr... | Mesopelagic zone | Wikipedia | 506 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
The mesopelagic is home to a significant portion of the world's total fish biomass. Mesopelagic fish are found globally, with exceptions in the Arctic Ocean. A 1980 study puts the mesopelagic fish biomass at about one billion tons. Then a 2008 study estimated the world marine fish biomass at between 0.8 and 2 billion t... | Mesopelagic zone | Wikipedia | 438 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
Mesopelagic fish are adapted to a low-light environment. Many fish are black or red, because these colors appear dark due to the limited light penetration at depth. Some fish have rows of photophores, small light-producing organs, on their underside to mimic the surrounding environment. Other fish have mirrored bodie... | Mesopelagic zone | Wikipedia | 439 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
Bioaccumulation
Bioaccumulation (a buildup of a certain substance in the adipose tissue) and biomagnification (the process in which the concentration of the substance grows higher as you rise through the food chain) are growing issues in the mesopelagic zone. Mercury in fish can be traced back to a combination of anth... | Mesopelagic zone | Wikipedia | 434 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
As the biomass in the mesopelagic is so abundant, there has been an increased interest to determine whether these populations could be of economic use in sectors other than direct human consumption. For example, it has been suggested that the high abundance of fish in this zone could potentially satisfy a demand for fi... | Mesopelagic zone | Wikipedia | 411 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
Water column stratification will also likely increase with ocean warming and climate change. Increased ocean stratification reduces the introduction of nutrients from the deep ocean into the euphotic zone resulting in decreases in both net primary production and sinking particulate matter. Additional research suggests ... | Mesopelagic zone | Wikipedia | 420 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
Discovery and Detection
The deep scattering layer often characterizes the mesopelagic due to the high amount of biomass that exists in the region. Acoustic sound sent into the ocean bounces off particles and organisms in the water column and return a strong signal. The region was initially discovered by American resea... | Mesopelagic zone | Wikipedia | 457 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
MINIONS
Another mesopelagic robot developed by WHOI are the MINIONS. This device descends down the water column and takes images of the amount and size distribution of marine snow at various depths. These tiny particles are a food source for other organisms so it is important to monitor the different levels of marine s... | Mesopelagic zone | Wikipedia | 218 | 565530 | https://en.wikipedia.org/wiki/Mesopelagic%20zone | Physical sciences | Oceanography | Earth science |
The bathypelagic zone or bathyal zone (from Greek βαθύς (bathýs), deep) is the part of the open ocean that extends from a depth of below the ocean surface. It lies between the mesopelagic above and the abyssopelagic below. The bathypelagic is also known as the midnight zone because of the lack of sunlight; this featur... | Bathypelagic zone | Wikipedia | 511 | 565536 | https://en.wikipedia.org/wiki/Bathypelagic%20zone | Physical sciences | Oceanography | Earth science |
Many of the biogeochemical processes in the bathypelagic region are dependent upon the input of organic matter from the overlying epipelagic and mesopelagic zones. This organic material, sometimes called marine snow, sinks in the water column or is transported within downward convected water masses such as the Thermoha... | Bathypelagic zone | Wikipedia | 437 | 565536 | https://en.wikipedia.org/wiki/Bathypelagic%20zone | Physical sciences | Oceanography | Earth science |
As POM sinks through the water column, it is consumed by organisms which deplete it of nutrients. The size and density of these particles affect their likelihood of reaching organisms in the bathypelagic zone. Smaller parcels of POM often become aggregated together as they fall, which quickens their descent and prohibi... | Bathypelagic zone | Wikipedia | 375 | 565536 | https://en.wikipedia.org/wiki/Bathypelagic%20zone | Physical sciences | Oceanography | Earth science |
Calcium carbonate dissolution
The region in the water column at which calcite dissolution begins to occur rapidly, known as the lysocline, is typically located near the base bathypelagic zone at approximately 3,500 m depth, but varies among ocean basins. The lysocline lies below the saturation depth (the transition to... | Bathypelagic zone | Wikipedia | 425 | 565536 | https://en.wikipedia.org/wiki/Bathypelagic%20zone | Physical sciences | Oceanography | Earth science |
Prokaryote biomass in the bathypelagic is dependent and thus correlated with the amount of sinking POM and organic carbon availability. These essential organic carbon inputs for microbes typically decrease with depth as they are utilized while sinking to the bathypelagic. Microbial production varies over six orders of ... | Bathypelagic zone | Wikipedia | 454 | 565536 | https://en.wikipedia.org/wiki/Bathypelagic%20zone | Physical sciences | Oceanography | Earth science |
Viruses influence biogeochemical cycling through the role they play in marine food webs. Their overall abundance can be up to two orders of magnitude lower than the mesopelagic zone, however, there is often high viral abundance found around deep-sea hydrothermal vents. The magnitude of their impacts on biological syste... | Bathypelagic zone | Wikipedia | 304 | 565536 | https://en.wikipedia.org/wiki/Bathypelagic%20zone | Physical sciences | Oceanography | Earth science |
Diel vertical migration
Some bathypelagic species undergo vertical migration, which differs from the diel vertical migration of mesopelagic species in that it is not driven by sunlight. Instead, the migration of bathypelagic organisms is driven by other factors, most of which remain unknown. Some research suggests the... | Bathypelagic zone | Wikipedia | 441 | 565536 | https://en.wikipedia.org/wiki/Bathypelagic%20zone | Physical sciences | Oceanography | Earth science |
The oceans act as a buffer for anthropogenic climate change due to their ability to take up atmospheric CO2 and absorb heat from the atmosphere. However, the ocean's ability to do so will be negatively affected as atmospheric CO2 concentrations continue to rise and global temperatures continue to warm. This will lead t... | Bathypelagic zone | Wikipedia | 332 | 565536 | https://en.wikipedia.org/wiki/Bathypelagic%20zone | Physical sciences | Oceanography | Earth science |
Centaurea cyanus, commonly known as cornflower or bachelor's button, is an annual flowering plant in the family Asteraceae native to Europe. In the past, it often grew as a weed in cornfields (in the broad sense of "corn", referring to grains, such as wheat, barley, rye, or oats), hence its name. It is now endangered i... | Centaurea cyanus | Wikipedia | 482 | 566041 | https://en.wikipedia.org/wiki/Centaurea%20cyanus | Biology and health sciences | Asterales | Plants |
Weed in arable crops
Centaurea cyanus is considered a noxious weed in arable crops, especially cereals and rapeseed. In winter wheat, one plant per m2 can cause a yield loss of up to 30 kg / ha. Centaurea cyanus produces around 800 seed per plant, which are either shed shortly before the harvest of cereals, or they ar... | Centaurea cyanus | Wikipedia | 355 | 566041 | https://en.wikipedia.org/wiki/Centaurea%20cyanus | Biology and health sciences | Asterales | Plants |
Control of insect pests
Centaurea cyanus was found to produce volatiles attracting Microplitis mediator, which is a major parasitoid of the cabbage moth (Mamestra brassicae), which is the most important pest of cabbage (Brassica oleracea) in central Europe. Planting Centaurea cyanus in cabbage fields as a companion pl... | Centaurea cyanus | Wikipedia | 426 | 566041 | https://en.wikipedia.org/wiki/Centaurea%20cyanus | Biology and health sciences | Asterales | Plants |
Sowing
For summer-blooming plants, sowing should be executed in late spring. In moderate climates, however, it is also possible to sow Centaurea cyanus in early fall. In this case, plants will already start to flower in the following spring. Recommended spacing between plants is approx. 20 to 30 cm. Centaurea cyanus c... | Centaurea cyanus | Wikipedia | 472 | 566041 | https://en.wikipedia.org/wiki/Centaurea%20cyanus | Biology and health sciences | Asterales | Plants |
Medicine
Centaurea cyanus contains a wide range of pharmacologically active compounds, such as flavonoids, anthocyanins and aromatic acids. Especially the flower head finds application in herbal medicine, but leaves and seeds are also used for pharmacological purposes, albeit to a lesser extent.
In particular, extrac... | Centaurea cyanus | Wikipedia | 507 | 566041 | https://en.wikipedia.org/wiki/Centaurea%20cyanus | Biology and health sciences | Asterales | Plants |
It was also the favourite flower of Louise's son Kaiser Wilhelm I. Because of its ties to royalty, authors such as Theodor Fontane have used it symbolically, often sarcastically, to comment on the social and political climate of the time.
The cornflower is also often seen as an inspiration for the German Romantic symb... | Centaurea cyanus | Wikipedia | 370 | 566041 | https://en.wikipedia.org/wiki/Centaurea%20cyanus | Biology and health sciences | Asterales | Plants |
In solid-state physics, a metal–semiconductor (M–S) junction is a type of electrical junction in which a metal comes in close contact with a semiconductor material. It is the oldest type of practical semiconductor device. M–S junctions can either be rectifying or non-rectifying. The rectifying metal–semiconductor ju... | Metal–semiconductor junction | Wikipedia | 468 | 14355756 | https://en.wikipedia.org/wiki/Metal%E2%80%93semiconductor%20junction | Physical sciences | Electrical circuits | Physics |
The Schottky–Mott rule of Schottky barrier formation, named for Walter H. Schottky and Nevill Mott, predicts the Schottky barrier height based on the vacuum work function of the metal relative to the vacuum electron affinity (or vacuum ionization energy) of the semiconductor:
This model is derived based on the thought... | Metal–semiconductor junction | Wikipedia | 464 | 14355756 | https://en.wikipedia.org/wiki/Metal%E2%80%93semiconductor%20junction | Physical sciences | Electrical circuits | Physics |
The Fermi level pinning effect is strong in many commercially important semiconductors (Si, Ge, GaAs), and thus can be problematic for the design of semiconductor devices. For example, nearly all metals form a significant Schottky barrier to n-type germanium and an ohmic contact to p-type germanium, since the valence b... | Metal–semiconductor junction | Wikipedia | 316 | 14355756 | https://en.wikipedia.org/wiki/Metal%E2%80%93semiconductor%20junction | Physical sciences | Electrical circuits | Physics |
The earliest metal–semiconductor diodes in electronics application occurred around 1900, when the cat's whisker rectifiers were used in receivers. They consisted of pointed tungsten wire (in the shape of a cat's whisker) whose tip or point was pressed against the surface of a galena (lead sulfide) crystal. The first la... | Metal–semiconductor junction | Wikipedia | 239 | 14355756 | https://en.wikipedia.org/wiki/Metal%E2%80%93semiconductor%20junction | Physical sciences | Electrical circuits | Physics |
The first theory that predicted the correct direction of rectification of the metal–semiconductor junction was given by Nevill Mott in 1939. He found the solution for both the diffusion and drift currents of the majority carriers through the semiconductor surface space charge layer which has been known since about 1948... | Metal–semiconductor junction | Wikipedia | 468 | 14355756 | https://en.wikipedia.org/wiki/Metal%E2%80%93semiconductor%20junction | Physical sciences | Electrical circuits | Physics |
The first silicon oxide gate transistor were invented by Frosch and Derick in 1957 at Bell Labs. In 1956, Richard Baker described some discrete diode clamp circuits to keep transistors from saturating. The circuits are now known as Baker clamps. One of those clamp circuits used a single germanium diode to clamp a sili... | Metal–semiconductor junction | Wikipedia | 336 | 14355756 | https://en.wikipedia.org/wiki/Metal%E2%80%93semiconductor%20junction | Physical sciences | Electrical circuits | Physics |
The smart grid is an enhancement of the 20th century electrical grid, using two-way communications and distributed so-called intelligent devices. Two-way flows of electricity and information could improve the delivery network. Research is mainly focused on three systems of a smart grid – the infrastructure system, the ... | Smart grid | Wikipedia | 502 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
In the 20th century, local grids grew over time and were eventually interconnected for economic and reliability reasons. By the 1960s, the electric grids of developed countries had become very large, mature, and highly interconnected, with thousands of 'central' generation power stations delivering power to major load ... | Smart grid | Wikipedia | 474 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
From the 1970s to the 1990s, growing demand led to increasing numbers of power stations. In some areas, the supply of electricity, especially at peak times, could not keep up with this demand, resulting in poor power quality including blackouts, power cuts, and brownouts. Increasingly, electricity was depended on for i... | Smart grid | Wikipedia | 457 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
United States
The first official definition of Smart Grid was provided by the Energy Independence and Security Act of 2007 (EISA-2007), which was approved by the US Congress in January 2007, and signed to law by President George W. Bush in December 2007. Title XIII of this bill provides a description, with ten charact... | Smart grid | Wikipedia | 470 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Better facilitate the connection and operation of generators of all sizes and technologies.
Allow consumers to play a part in optimising the operation of the system.
Provide consumers with greater information and options for how they use their supply.
Significantly reduce the environmental impact of the whole electr... | Smart grid | Wikipedia | 502 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Monitoring and synchronization of wide-area networks were revolutionized in the early 1990s when the Bonneville Power Administration expanded its smart grid research with prototype sensors that are capable of very rapid analysis of anomalies in electricity quality over very large geographic areas. The culmination of th... | Smart grid | Wikipedia | 480 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Flexibility in network topology
Next-generation transmission and distribution infrastructure will be better able to handle possible bidirectional energy flows, allowing for distributed generation such as from photovoltaic panels on building roofs, but also charging to/from the batteries of electric cars, wind turbines... | Smart grid | Wikipedia | 463 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
To reduce demand during the high-cost peak usage periods, communications and metering technologies inform smart devices in the home and business when energy demand is high and track how much electricity is used and when it is used. It also gives utility companies the ability to reduce consumption by communicating to de... | Smart grid | Wikipedia | 406 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Market-enabling
The smart grid allows for systematic communication between suppliers (their energy price) and consumers (their willingness-to-pay), and permits both the suppliers and the consumers to be more flexible and sophisticated in their operational strategies. Only the critical loads will need to pay the peak e... | Smart grid | Wikipedia | 468 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Demand response can be provided by commercial, residential loads, and industrial loads. For example, Alcoa's Warrick Operation is participating in MISO as a qualified Demand Response Resource, and the Trimet Aluminium uses its smelter as a short-term mega-battery.
Latency of the data flow is a major concern, with some... | Smart grid | Wikipedia | 100 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
The bulk of smart grid technologies are already used in other applications such as manufacturing and telecommunications and are being adapted for use in grid operations.
Integrated communications: Areas for improvement include: substation automation, demand response, distribution automation, supervisory control, and d... | Smart grid | Wikipedia | 332 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Smart power generation using advanced components: smart power generation is a concept of matching electricity generation with demand using multiple identical generators which can start, stop and operate efficiently at chosen load, independently of the others, making them suitable for baseload and peaking power generati... | Smart grid | Wikipedia | 389 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Research
Major programs
IntelliGrid – Created by the Electric Power Research Institute (EPRI), IntelliGrid architecture provides methodology, tools, and recommendations for standards and technologies for utility use in planning, specifying, and procuring IT-based systems, such as advanced metering, distribution autom... | Smart grid | Wikipedia | 477 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
GridWise Architecture Council (GWAC) was formed by the U.S. Department of Energy to promote and enable interoperability among the many entities that interact with the nation's electric power system. The GWAC members are a balanced and respected team representing the many constituencies of the electricity supply chain a... | Smart grid | Wikipedia | 320 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Smart Grid Energy Research Center (SMERC) - Located at University of California, Los Angeles dedicated its efforts to large-scale testing of its smart EV charging network technology. It created another platform for bidirectional flow of information between a utility and consumer end-devices. SMERC also developed a dema... | Smart grid | Wikipedia | 465 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Kuramoto oscillators
The Kuramoto model is a well-studied system. The power grid has been described in this context as well. The goal is to keep the system in balance, or to maintain phase synchronization (also known as phase locking). Non-uniform oscillators also help to model different technologies, different types o... | Smart grid | Wikipedia | 456 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Markov processes
As wind power continues to gain popularity, it becomes a necessary ingredient in realistic power grid studies. Off-line storage, wind variability, supply, demand, pricing, and other factors can be modelled as a mathematical game. Here the goal is to develop a winning strategy. Markov processes have bee... | Smart grid | Wikipedia | 465 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
A 2003 United States Department of Energy study calculated that internal modernization of US grids with smart grid capabilities would save between 46 and 117 billion dollars over the next 20 years if implemented within a few years of the study. As well as these industrial modernization benefits, smart grid features cou... | Smart grid | Wikipedia | 456 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Most opposition and concerns have centered on smart meters and the items (such as remote control, remote disconnect, and variable rate pricing) enabled by them. Where opposition to smart meters is encountered, they are often marketed as "smart grid" which connects smart grid to smart meters in the eyes of opponents. Sp... | Smart grid | Wikipedia | 417 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
There is also concern on the security of the infrastructure, primarily that involving communications technology. Concerns chiefly center around the communications technology at the heart of the smart grid. Designed to allow real-time contact between utilities and meters in customers' homes and businesses, there is a ri... | Smart grid | Wikipedia | 382 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
The December 2015 Ukraine power grid cyberattack, the first recorded of its kind, disrupted services to nearly a quarter of a million people by bringing substations offline. The Council on Foreign Relations has noted that states are most likely to be the perpetrators of such an attack as they have access to the resourc... | Smart grid | Wikipedia | 388 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Some experts argue that the first step to increasing the cyber defenses of the smart electric grid is completing a comprehensive risk analysis of existing infrastructure, including research of software, hardware, and communication processes. Additionally, as intrusions themselves can provide valuable information, it co... | Smart grid | Wikipedia | 507 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
The protection system of a smart grid provides grid reliability analysis, failure protection, and security and privacy protection services. While the additional communication infrastructure of a smart grid provides additional protective and security mechanisms, it also presents a risk of external attack and internal fa... | Smart grid | Wikipedia | 462 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
The incorporation of digital communications and computer infrastructure with the grid's existing physical infrastructure poses challenges and inherent vulnerabilities. According to IEEE Security and Privacy Magazine, the smart grid will require that people develop and use large computer and communication infrastructure... | Smart grid | Wikipedia | 334 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
US Dept. of Energy - ARRA Smart Grid Project
One of the largest deployment programs in the world to-date is the U.S. Dept. of Energy's Smart Grid Program funded by the American Recovery and Reinvestment Act of 2009. This program required matching funding from individual utilities. A total of over $9 billion in Public/... | Smart grid | Wikipedia | 447 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Hydro One
Hydro One, in Ontario, Canada is in the midst of a large-scale Smart Grid initiative, deploying a standards-compliant communications infrastructure from Trilliant. By the end of 2010, the system will serve 1.3 million customers in the province of Ontario. The initiative won the "Best AMR Initiative in North ... | Smart grid | Wikipedia | 500 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Massachusetts
One of the first attempted deployments of "smart grid" technologies in the United States was rejected in 2009 by electricity regulators in the Commonwealth of Massachusetts, a US state. According to an article in the Boston Globe, Northeast Utilities' Western Massachusetts Electric Co. subsidiary actuall... | Smart grid | Wikipedia | 347 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Chattanooga
EPB in Chattanooga, TN is a municipally-owned electric utility that started construction of a smart grid in 2008, receiving a $111,567,606 grant from the US DOE in 2009 to expedite construction and implementation (for a total budget of $232,219,350). Deployment of power-line interrupters (1170 units) was c... | Smart grid | Wikipedia | 501 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Guidelines, standards and user groups
Part of the IEEE Smart Grid Initiative, IEEE 2030.2 represents an extension of the work aimed at utility storage systems for transmission and distribution networks. The IEEE P2030 group expects to deliver early 2011 an overarching set of guidelines on smart grid interfaces. The new... | Smart grid | Wikipedia | 494 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
OASIS EnergyInterop' – An OASIS technical committee developing XML standards for energy interoperation. Its starting point is the California OpenADR standard.
Under the Energy Independence and Security Act of 2007 (EISA), NIST is charged with overseeing the identification and selection of hundreds of standards that wi... | Smart grid | Wikipedia | 320 | 13201685 | https://en.wikipedia.org/wiki/Smart%20grid | Technology | Electricity transmission and distribution | null |
Turritopsis dohrnii, also known as the immortal jellyfish, is a species of small, biologically immortal jellyfish found worldwide in temperate to tropic waters. It is one of the few known cases of animals capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a so... | Turritopsis dohrnii | Wikipedia | 506 | 9214162 | https://en.wikipedia.org/wiki/Turritopsis%20dohrnii | Biology and health sciences | Cnidarians | Animals |
The medusa of Turritopsis dohrnii is bell-shaped, with a maximum diameter of about and is about as tall as it is wide. The mesoglea in the walls of the bell is uniformly thin, except for some thickening at the apex. The relatively large stomach is bright red and has a cruciform shape in cross section. Young specimens ... | Turritopsis dohrnii | Wikipedia | 390 | 9214162 | https://en.wikipedia.org/wiki/Turritopsis%20dohrnii | Biology and health sciences | Cnidarians | Animals |
The eggs develop in gonads of female medusae, which are located in the walls of the manubrium (stomach). Mature eggs are presumably spawned and fertilized in the sea by sperm produced and released by male medusae, as is the case for most hydromedusae. However, the related species Turritopsis rubra seems to retain ferti... | Turritopsis dohrnii | Wikipedia | 319 | 9214162 | https://en.wikipedia.org/wiki/Turritopsis%20dohrnii | Biology and health sciences | Cnidarians | Animals |
Experiments have revealed that all stages of the medusae, from newly released to fully mature individuals, can transform back into polyps under the conditions of starvation, sudden temperature change, reduction of salinity, and artificial damage of the bell with forceps or scissors. The transforming medusa is character... | Turritopsis dohrnii | Wikipedia | 409 | 9214162 | https://en.wikipedia.org/wiki/Turritopsis%20dohrnii | Biology and health sciences | Cnidarians | Animals |
Diet
Turritopsis dohrnii are a carnivorous species that commonly feed on zooplankton. Their diet mainly consists of plankton, fish eggs and small mollusks. T. dohrnii ingests food and excretes waste through the mouth. T. dohrnii hunts by using its tentacles as it drifts through the water. Its tentacles, which contain... | Turritopsis dohrnii | Wikipedia | 480 | 9214162 | https://en.wikipedia.org/wiki/Turritopsis%20dohrnii | Biology and health sciences | Cnidarians | Animals |
Analysis of nucleotide sequence homologs and protein homologs identified Nemopsis bachei as the species' closest relative. None of the closely related species display biological immortality.
In 2022, a study reported the key molecular mechanisms of rejuvenation they found in a comparison of the newly presented genomes... | Turritopsis dohrnii | Wikipedia | 224 | 9214162 | https://en.wikipedia.org/wiki/Turritopsis%20dohrnii | Biology and health sciences | Cnidarians | Animals |
In chemistry, transition state theory (TST) explains the reaction rates of elementary chemical reactions. The theory assumes a special type of chemical equilibrium (quasi-equilibrium) between reactants and activated transition state complexes.
TST is used primarily to understand qualitatively how chemical reactions ta... | Transition state theory | Wikipedia | 445 | 9217017 | https://en.wikipedia.org/wiki/Transition%20state%20theory | Physical sciences | Kinetics | Chemistry |
Rates of reaction can be studied by examining activated complexes near the saddle point of a potential energy surface. The details of how these complexes are formed are not important. The saddle point itself is called the transition state.
The activated complexes are in a special equilibrium (quasi-equilibrium) with t... | Transition state theory | Wikipedia | 509 | 9217017 | https://en.wikipedia.org/wiki/Transition%20state%20theory | Physical sciences | Kinetics | Chemistry |
However, later when the same treatment was applied to other reactions, there were large discrepancies between theoretical and experimental results.
Statistical-mechanical treatment
Statistical mechanics played a significant role in the development of TST. However, the application of statistical mechanics to TST was d... | Transition state theory | Wikipedia | 476 | 9217017 | https://en.wikipedia.org/wiki/Transition%20state%20theory | Physical sciences | Kinetics | Chemistry |
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