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The double-sided metallized film is electrostatically field-free because the electrodes have the same voltage potential on both sides of the film, and therefore does not contribute to the total capacitance of the capacitor. This film can therefore be made of a different and less expensive material. For example, a polyp... | Film capacitor | Wikipedia | 438 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
With the development of plastic materials by organic chemists during the Second World War, the capacitor industry began to replace paper with thinner polymer films. One very early development in film capacitors was described in British Patent 587,953 in 1944. The introduction of plastics in plastic film capacitors was ... | Film capacitor | Wikipedia | 483 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
An early special type of plastic film capacitors were the cellulose acetate film capacitors, also called MKU capacitors. The polar insulating dielectric cellulose acetate was a synthetic resin that could be made for metallized capacitors in paint film thickness down to about 3 μm. A liquid layer of cellulose acetate w... | Film capacitor | Wikipedia | 498 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
As of 2012, only five plastic materials continued to be widely used in the capacitor industry as films for capacitors: PET, PEN, PP, PPS and PTFE. Other plastic materials are no longer in common use, either because they are no longer manufactured, or they have been replaced with better materials. Even the long-time man... | Film capacitor | Wikipedia | 499 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Polypropylene film capacitors have a dielectric made of the thermoplastic, non-polar, organic and partially crystalline polymer material Polypropylene (PP), trade name Treofan, from the family of polyolefins. They are manufactured both as metallized wound and stacked versions, as well as film/foil types. Polypropylene ... | Film capacitor | Wikipedia | 442 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
The dissipation factor of PP film capacitors is smaller than that of other film capacitors. Due to the low and very stable dissipation factor over a wide temperature and frequency range, even at very high frequencies, and their high dielectric strength of 650 V/μm, PP film capacitors can be used in metallized and in fi... | Film capacitor | Wikipedia | 359 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Polyester (PET) film capacitors
Polyester film capacitors are film capacitors using a dielectric made of the thermoplastic polar polymer material polyethylene terephthalate (PET), trade names Hostaphan or Mylar, from the polyester family. They are manufactured both as metallized wound and stacked versions, as well as... | Film capacitor | Wikipedia | 409 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Polyethylene naphthalate (PEN) film capacitors
Polyethylene naphthalate film capacitors are film capacitors using a dielectric made of the thermoplastic biaxial polymer material polyethylene naphthalate (PEN), trade names Kaladex, Teonex. They are produced only as metallized types. PEN, like PET, belongs to the polye... | Film capacitor | Wikipedia | 371 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
The temperature dependence of the capacitance of PPS film capacitors over the entire temperature range is very small (± 1.5%) compared with other film capacitors. Also the frequency dependence in the range from 100 Hz to 100 kHz of the capacitance of the PPS film capacitors is ± 0.5%, very low compared with other film ... | Film capacitor | Wikipedia | 422 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Polytetrafluoroethylene film capacitors feature a very high temperature resistance up to 200 °C, and even further up to 260 °C, with a voltage derating. The dissipation factor 2 • 10 −4 is quite small. The change in capacitance over the entire temperature range of +1% to -3% is a little bit higher than for polypropyl... | Film capacitor | Wikipedia | 504 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
These capacitors have a low dissipation factor and because of their relatively temperature-independent electrical properties of about ±80 ppm over the entire temperature range, they had many applications for low-loss and temperature-stable applications such as timing circuits, precision analog circuits, and signal filt... | Film capacitor | Wikipedia | 472 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
However, the roughness of a metallized paper surface can cause many small air-filled bubbles between the dielectric and the metallization, decreasing the breakdown voltage of the capacitor. For this reason, larger film capacitors or power capacitors using paper as carrier of the electrodes usually are filled with an in... | Film capacitor | Wikipedia | 362 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Polyimide (PI), a thermoplastic polymer of imide monomers, is proposed for film capacitors called Polyimide-, PI- or Kapton capacitors. Kapton is the trade name of polyimide from DuPont. This material is of interest because its high temperature resistance up to 400 °C. But as of 2012, no specific PI capacitor series fi... | Film capacitor | Wikipedia | 495 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
The standardization of power capacitors is strongly focused on rules for the safety of personnel and equipment, given by the local regulating authority. The concepts and definitions to guarantee safe application of power capacitors are published in the following standards:
IEC/EN 61071; Capacitors for power electronic... | Film capacitor | Wikipedia | 500 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
IEC/EN 60931-3; Shunt power capacitors of the non-self-healing type for a.c. systems having a rated voltage up to and including 1000 V. Internal fuses
IEC/EN 61881-1; Railway applications. Rolling stock equipment. Capacitors for power electronics. Paper/plastic film capacitors
IEC 62146-1; Grading capacitors for high... | Film capacitor | Wikipedia | 94 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
The text above is directly extracted from the relevant IEC standards, which use the abbreviations "d.c." for Direct Current (DC) and "a.c." for Alternating Current (AC).
Film capacitors type abbreviations
During the early development of film capacitors, some large manufacturers have tried to standardize the names of ... | Film capacitor | Wikipedia | 394 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Capacitance standard values and tolerances
The rated capacitance is the value for which the capacitor has been designed. The actual capacitance of film capacitors depends on the measuring frequency and the ambient temperature. Standardized conditions for film capacitors are a measuring frequency of 1 kHz and a tempera... | Film capacitor | Wikipedia | 456 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
The breakdown voltage of film capacitors decreases with increasing temperature. When using film capacitors at temperatures between the upper rated temperature and the upper category temperature, only a temperature-derated category voltage VC is allowed. The derating factors apply to both DC and AC voltages. Some manufa... | Film capacitor | Wikipedia | 388 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Capacitors, including film types, designed for continuous operation at low-frequency (50 or 60 Hz) mains voltage, typically between line and neutral or line and ground for interference suppression, are required to meet standard safety ratings; e.g., X2 is designed to operate between line and neutral at 200-240 VAC, and... | Film capacitor | Wikipedia | 507 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
For each individual application, the pulse load must be calculated. A general rule for calculating the power handling of film capacitors is not available because of vendor-related differences stemming from the internal construction details of different capacitors. Therefore, the calculation procedure of the manufacture... | Film capacitor | Wikipedia | 486 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
This reason for using the dissipation factor instead of the ESR is, that film capacitors were originally used mainly in frequency-determining resonant circuits. The reciprocal value of the dissipation factor is defined as the quality factor "Q". A high Q value is for resonant circuits a mark of the quality of the res... | Film capacitor | Wikipedia | 483 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Aging
Film capacitors are subject to certain very small but measurable aging processes. The primary degradation process is a small amount of plastic film shrinkage, which occurs mainly during the soldering process, but also during operation at high ambient temperatures or at high current load. Additionally, some mois... | Film capacitor | Wikipedia | 496 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Capacitance, tolerance, and date of manufacture can be marked with short codes. Capacitance is often indicated with the sub-multiple indicator replacing an easily erased decimal point, as: n47 = 0.47 nF, 4n7 = 4.7 nF, 47n = 47 nF
Applications
In comparison with the other two main capacitor technologies, ceramic and ... | Film capacitor | Wikipedia | 447 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Fast pulse rise time rating, high dielectric strength (breakdown voltage), and low dissipation factor (high Q) are the reasons for the use of polypropylene film capacitors in fly-back tuning and S-correction applications in older CRT tube television and display equipment. For similar reasons, PP film capacitors, often ... | Film capacitor | Wikipedia | 508 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Safety and EMI/RFI suppression film capacitors
Electromagnetic interference (EMI) or radio-frequency interference (RFI) suppression film capacitors, also known as "AC line filter safety capacitors" or "Safety capacitors", are used as crucial components to reduce or suppress electrical noise caused by the operation of... | Film capacitor | Wikipedia | 423 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
RFI capacitors which fulfill all specified requirements are imprinted with the certification mark of various national safety standards agencies. For power line applications, special requirements are placed on the inflammability of the coating and the epoxy resin impregnating or coating the capacitor body. To receive sa... | Film capacitor | Wikipedia | 487 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
Snubbers are energy-absorbing circuits used to eliminate voltage spikes caused by circuit inductance when a switch opens. The purpose of the snubber is to improve electromagnetic compatibility (EMC) by eliminating the voltage transient that occurs when a switch abruptly opens, or by suppressing sparking of switch conta... | Film capacitor | Wikipedia | 450 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
The overlapping categories of film and power capacitors are visible when they are applied as snubber capacitors in the growing market for high power electronics with IGBT's and thyristors. Although the power capacitors use polypropylene film, like the smaller snubber film capacitors, they belong to the family of power ... | Film capacitor | Wikipedia | 469 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
The scope of application for DC capacitors is similarly diverse. Smoothing capacitors are used to reduce the AC component of fluctuating DC voltage (such as in power supplies for radio and television transmitters), and for high voltage testing equipment, DC controllers, measurement and control technology and cascaded c... | Film capacitor | Wikipedia | 404 | 35034187 | https://en.wikipedia.org/wiki/Film%20capacitor | Technology | Components | null |
A uniform resource locator (URL), colloquially known as an address on the Web, is a reference to a resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifier (URI), although many people use the two terms interchangeably. URLs occ... | URL | Wikipedia | 499 | 47817022 | https://en.wikipedia.org/wiki/URL | Technology | Internet | null |
Every HTTP URL conforms to the syntax of a generic URI.
A web browser will usually dereference a URL by performing an HTTP request to the specified host, by default on port number 80. URLs using the https scheme require that requests and responses be made over a secure connection to the website.
Internationalized UR... | URL | Wikipedia | 442 | 47817022 | https://en.wikipedia.org/wiki/URL | Technology | Internet | null |
Thermochronology is the study of the thermal evolution of a region of a planet. Thermochronologists use radiometric dating along with the closure temperatures that represent the temperature of the mineral being studied at the time given by the date recorded to understand the thermal history of a specific rock, mineral,... | Thermochronology | Wikipedia | 377 | 21866506 | https://en.wikipedia.org/wiki/Thermochronology | Physical sciences | Geochronology | Earth science |
For thermochronology, the ages associated with these isotopic ratios is directly linked with the sample's thermal history. At high temperatures, the rocks will behave as if they are in an open system, which relates to the increased rate of diffusion of the daughter isotopes out of the mineral. At low temperatures, howe... | Thermochronology | Wikipedia | 459 | 21866506 | https://en.wikipedia.org/wiki/Thermochronology | Physical sciences | Geochronology | Earth science |
Potassium-Argon/Argon-Argon Dating
Potassium-Argon/Argon-Argon dating is applied in thermochronology in order to find the age of the minerals, such as apatite. Potassium-argon (K-Ar) dating is concerned with determining the amount of the product of radioactive decay of isotopic potassium (40K) into its decay product o... | Thermochronology | Wikipedia | 404 | 21866506 | https://en.wikipedia.org/wiki/Thermochronology | Physical sciences | Geochronology | Earth science |
Applications
By determining the relative date and temperature of a sample being studied, geologists are able to understand the structural information of the deposits. Thermochronology is used in a wide variety of subjects today, such as tectonic studies, exhumation of mountain belts, hydrothermal ore deposits, and eve... | Thermochronology | Wikipedia | 110 | 21866506 | https://en.wikipedia.org/wiki/Thermochronology | Physical sciences | Geochronology | Earth science |
Mucoromycotina is a subphylum of uncertain placement in Fungi. It was considered part of the phylum Zygomycota, but recent phylogenetic studies have shown that it was polyphyletic and thus split into several groups, it is now thought to be a paraphyletic grouping. Mucoromycotina is currently composed of 3 orders, 61 ge... | Mucoromycotina | Wikipedia | 479 | 21869208 | https://en.wikipedia.org/wiki/Mucoromycotina | Biology and health sciences | Basics | Plants |
This order currently contains 2 families, (Endogonaceae and Densosporaceae) 7 genera, and 40 species. Not much is known about this order, other than readily noticeable characteristics. They produce subterranean sporocarps, which are ingested by small mammals attracted by the fetid odor they produce. Cultured specimens ... | Mucoromycotina | Wikipedia | 470 | 21869208 | https://en.wikipedia.org/wiki/Mucoromycotina | Biology and health sciences | Basics | Plants |
The species described in this subphylum have evolved 3 main lifestyles: saprotrophic, mycorrhizal, or parasitic. Saprotrophic species are involved in decomposition of organic matter, mycorrhizal species form symbiotic relationships with plants, and parasitic species form harmful symbiotic relationships with other organ... | Mucoromycotina | Wikipedia | 510 | 21869208 | https://en.wikipedia.org/wiki/Mucoromycotina | Biology and health sciences | Basics | Plants |
The genus Endogone is important in nutrient-deficient soils, such as sand dunes. The presence of species in this genus stabilizes the soil and provides some assistance to dune plants.
Mucorales
Some species in the genus Mucor are well known for causing crown rot in cereal plants and damage to stored foods.
Mortierell... | Mucoromycotina | Wikipedia | 467 | 21869208 | https://en.wikipedia.org/wiki/Mucoromycotina | Biology and health sciences | Basics | Plants |
Crown rot is a plant disease caused by species in Mucorales. The disease is characterized by rotting tissue at or near where the stem meets the soil. Treatment is difficult if not caught in its early stages, and usually results in the death of the plant. Crown rot is seen in cereal plants (wheat, barley), with experime... | Mucoromycotina | Wikipedia | 318 | 21869208 | https://en.wikipedia.org/wiki/Mucoromycotina | Biology and health sciences | Basics | Plants |
In cosmology, the steady-state model or steady state theory is an alternative to the Big Bang theory. In the steady-state model, the density of matter in the expanding universe remains unchanged due to a continuous creation of matter, thus adhering to the perfect cosmological principle, a principle that says that the ... | Steady-state model | Wikipedia | 405 | 26257152 | https://en.wikipedia.org/wiki/Steady-state%20model | Physical sciences | Physical cosmology | Astronomy |
Problems with the steady-state model began to emerge in the 1950s and 60s – observations supported the idea that the universe was in fact changing. Bright radio sources (quasars and radio galaxies) were found only at large distances (therefore could have existed only in the distant past due to the effects of the speed ... | Steady-state model | Wikipedia | 479 | 26257152 | https://en.wikipedia.org/wiki/Steady-state%20model | Physical sciences | Physical cosmology | Astronomy |
Quasi-steady state
Quasi-steady-state cosmology (QSS) was proposed in 1993 by Fred Hoyle, Geoffrey Burbidge, and Jayant V. Narlikar as a new incarnation of the steady-state ideas meant to explain additional features unaccounted for in the initial proposal. The model suggests pockets of creation occurring over time with... | Steady-state model | Wikipedia | 220 | 26257152 | https://en.wikipedia.org/wiki/Steady-state%20model | Physical sciences | Physical cosmology | Astronomy |
A drafting machine is a tool used in technical drawing, consisting of a pair of scales mounted to form a right angle on an articulated protractor head that allows an angular rotation.
The protractor head (two scales and protractor mechanism) is able to move freely across the surface of the drawing board, sliding on tw... | Drafting machine | Wikipedia | 481 | 26262533 | https://en.wikipedia.org/wiki/Drafting%20machine | Technology | Artist's and drafting tools | null |
In physics, Lagrangian mechanics is a formulation of classical mechanics founded on the stationary-action principle (also known as the principle of least action). It was introduced by the Italian-French mathematician and astronomer Joseph-Louis Lagrange in his presentation to the Turin Academy of Science in 1760 culmin... | Lagrangian mechanics | Wikipedia | 462 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
For a wide variety of physical systems, if the size and shape of a massive object are negligible, it is a useful simplification to treat it as a point particle. For a system of N point particles with masses m1, m2, ..., mN, each particle has a position vector, denoted r1, r2, ..., rN. Cartesian coordinates are often su... | Lagrangian mechanics | Wikipedia | 456 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
V, the potential energy of the system, reflects the energy of interaction between the particles, i.e. how much energy any one particle has due to all the others, together with any external influences. For conservative forces (e.g. Newtonian gravity), it is a function of the position vectors of the particles only, so F... | Lagrangian mechanics | Wikipedia | 485 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
If T or V or both depend explicitly on time due to time-varying constraints or external influences, the Lagrangian is explicitly time-dependent. If neither the potential nor the kinetic energy depend on time, then the Lagrangian is explicitly independent of time. In either case, the Lagrangian always has implicit tim... | Lagrangian mechanics | Wikipedia | 505 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
With these definitions, the Euler–Lagrange equations, or Lagrange's equations of the second kind
are mathematical results from the calculus of variations, which can also be used in mechanics. Substituting in the Lagrangian gives the equations of motion of the system. The number of equations has decreased compared to ... | Lagrangian mechanics | Wikipedia | 496 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
It may seem like an overcomplication to cast Newton's law in this form, but there are advantages. The acceleration components in terms of the Christoffel symbols can be avoided by evaluating derivatives of the kinetic energy instead. If there is no resultant force acting on the particle, it does not accelerate, but mo... | Lagrangian mechanics | Wikipedia | 458 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
The virtual displacements, δrk, are by definition infinitesimal changes in the configuration of the system consistent with the constraint forces acting on the system at an instant of time, i.e. in such a way that the constraint forces maintain the constrained motion. They are not the same as the actual displacements in... | Lagrangian mechanics | Wikipedia | 461 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
This is half of the conversion to generalized coordinates. It remains to convert the acceleration term into generalized coordinates, which is not immediately obvious. Recalling the Lagrange form of Newton's second law, the partial derivatives of the kinetic energy with respect to the generalized coordinates and velocit... | Lagrangian mechanics | Wikipedia | 507 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
Now, if the condition holds for all j, the terms not integrated are zero. If in addition the entire time integral of δL is zero, then because the δqj are independent, and the only way for a definite integral to be zero is if the integrand equals zero, each of the coefficients of δqj must also be zero. Then we obtain t... | Lagrangian mechanics | Wikipedia | 427 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
Hamilton's principle is still valid even if the coordinates L is expressed in are not independent, here rk, but the constraints are still assumed to be holonomic. As always the end points are fixed for all k. What cannot be done is to simply equate the coefficients of δrk to zero because the δrk are not independent. I... | Lagrangian mechanics | Wikipedia | 504 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
with the last two components and independent of q.
Invariance under point transformations
Given a set of generalized coordinates q, if we change these variables to a new set of generalized coordinates Q according to a point transformation which is invertible as , the new Lagrangian L′ is a function of the new coo... | Lagrangian mechanics | Wikipedia | 495 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
Conservation
In Lagrangian mechanics, the system is closed if and only if its Lagrangian does not explicitly depend on time. The energy conservation law states that the energy of a closed system is an integral of motion.
More precisely, let be an extremal. (In other words, satisfies the Euler–Lagrange equations).... | Lagrangian mechanics | Wikipedia | 501 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
This may be physically motivated by taking the non-interacting Lagrangians to be kinetic energies only, while the interaction Lagrangian is the system's total potential energy. Also, in the limiting case of negligible interaction, LAB tends to zero reducing to the non-interacting case above.
The extension to more than... | Lagrangian mechanics | Wikipedia | 512 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
The Lagrangian in two-dimensional polar coordinates is recovered by fixing θ to the constant value π/2.
Pendulum on a movable support
Consider a pendulum of mass m and length ℓ, which is attached to a support with mass M, which can move along a line in the -direction. Let be the coordinate along the line of the sup... | Lagrangian mechanics | Wikipedia | 502 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
The radial coordinate and angular velocity can vary with time, but only in such a way that is constant. The Lagrange equation for is
This equation is identical to the radial equation obtained using Newton's laws in a co-rotating reference frame, that is, a frame rotating with the reduced mass so it appears station... | Lagrangian mechanics | Wikipedia | 444 | 23371726 | https://en.wikipedia.org/wiki/Lagrangian%20mechanics | Physical sciences | Classical mechanics | null |
In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ.
The term pathogen came into use in the 1880s. Typically, the term pathogen is used t... | Pathogen | Wikipedia | 472 | 35038133 | https://en.wikipedia.org/wiki/Pathogen | Biology and health sciences | Infectious disease | null |
Virulence involves pathogens extracting host nutrients for their survival, evading host immune systems by producing microbial toxins and causing immunosuppression. Optimal virulence describes a theorized equilibrium between a pathogen spreading to additional hosts to parasitize resources, while lowering their virulence... | Pathogen | Wikipedia | 477 | 35038133 | https://en.wikipedia.org/wiki/Pathogen | Biology and health sciences | Infectious disease | null |
Prions are misfolded proteins that transmit their abnormal folding pattern to other copies of the protein without using nucleic acids. Besides obtaining prions from others, these misfolded proteins arise from genetic differences, either due to family history or sporadic mutations. Plants uptake prions from contaminated... | Pathogen | Wikipedia | 343 | 35038133 | https://en.wikipedia.org/wiki/Pathogen | Biology and health sciences | Infectious disease | null |
Viruses are generally between 20–200 nm in diameter. For survival and replication, viruses inject their genome into host cells, insert those genes into the host genome, and hijack the host's machinery to produce hundreds of new viruses until the cell bursts open to release them for additional infections. The lytic cycl... | Pathogen | Wikipedia | 506 | 35038133 | https://en.wikipedia.org/wiki/Pathogen | Biology and health sciences | Infectious disease | null |
Parasitic worms (helminths) are macroparasites that can be seen by the naked eye. Worms live and feed in their living host, acquiring nutrients and shelter in the digestive tract or bloodstream of their host. They also manipulate the host's immune system by secreting immunomodulatory products which allows them to live ... | Pathogen | Wikipedia | 417 | 35038133 | https://en.wikipedia.org/wiki/Pathogen | Biology and health sciences | Infectious disease | null |
Fungi are another major pathogen type for plants. They can cause a wide variety of issues such as shorter plant height, growths or pits on tree trunks, root or seed rot, and leaf spots. Common and serious plant fungi include the rice blast fungus, Dutch elm disease, chestnut blight and the black knot and brown rot dise... | Pathogen | Wikipedia | 409 | 35038133 | https://en.wikipedia.org/wiki/Pathogen | Biology and health sciences | Infectious disease | null |
Viruses
A variety of prevention and treatment options exist for some viral pathogens. Vaccines are one common and effective preventive measure against a variety of viral pathogens. Vaccines prime the immune system of the host, so that when the potential host encounters the virus in the wild, the immune system can defe... | Pathogen | Wikipedia | 457 | 35038133 | https://en.wikipedia.org/wiki/Pathogen | Biology and health sciences | Infectious disease | null |
Due to their indispensability in combating bacteria, new antibiotics are required for medical care. One target for new antimicrobial medications involves inhibiting DNA methyltransferases, as these proteins control the levels of expression for other genes, such as those encoding virulence factors.
Fungi
Infection by ... | Pathogen | Wikipedia | 456 | 35038133 | https://en.wikipedia.org/wiki/Pathogen | Biology and health sciences | Infectious disease | null |
Viruses may also undergo sexual interaction when two or more viral genomes enter the same host cell. This process involves pairing of homologous genomes and recombination between them by a process referred to as multiplicity reactivation. The herpes simplex virus, human immunodeficiency virus, and vaccinia virus underg... | Pathogen | Wikipedia | 103 | 35038133 | https://en.wikipedia.org/wiki/Pathogen | Biology and health sciences | Infectious disease | null |
Sichuan pepper (, also known as Sichuanese pepper, Szechuan pepper, Chinese prickly ash, Chinese pepper, Mountain pepper, and mala pepper, is a spice commonly used in Sichuan cuisine in China, Bhutan and in northeast India. It is called mejenga in Assam, India. It is called Thingey (ཐིང༌ངེ༌) in Bhutan and is used in pr... | Sichuan pepper | Wikipedia | 467 | 47839266 | https://en.wikipedia.org/wiki/Sichuan%20pepper | Biology and health sciences | Herbs and spices | Plants |
Zanthoxylum armatum is found throughout the Himalayas, from Kashmir to Bhutan, as well as in Taiwan, Nepal, China, Philippines, Malaysia, Japan, and Pakistan, and is known by a variety of regional names, including () in Nepali and Hindko, () in Tibetan and in Bhutan.
Other Zanthoxylum spices
Zanthoxylum gilletii ... | Sichuan pepper | Wikipedia | 477 | 47839266 | https://en.wikipedia.org/wiki/Sichuan%20pepper | Biology and health sciences | Herbs and spices | Plants |
Other regions
One Himalayan specialty is the momo, a dumpling stuffed with vegetables, cottage cheese, or minced yak or beef, and flavored with Sichuan pepper, garlic, ginger, and onion. In Nepal, the mala flavor is known as ().
In Korean cuisine, is often used to accompany fish soups such as chueo-tang.
In Indone... | Sichuan pepper | Wikipedia | 264 | 47839266 | https://en.wikipedia.org/wiki/Sichuan%20pepper | Biology and health sciences | Herbs and spices | Plants |
Important compounds of various Zanthoxylum species include:
Zanthoxylum fagara (Central & Southern Africa, South America) — alkaloids, coumarins (Phytochemistry, 27, 3933, 1988)
Zanthoxylum simulans (Taiwan) — Mostly beta-myrcene, limonene, 1,8-cineole, Z-beta-ocimene (J. Agri. & Food Chem., 44, 1096, 1996)
Zanthoxylum... | Sichuan pepper | Wikipedia | 436 | 47839266 | https://en.wikipedia.org/wiki/Sichuan%20pepper | Biology and health sciences | Herbs and spices | Plants |
Allium is a large genus of monocotyledonous flowering plants with around 1000 accepted species, making Allium the largest genus in the family Amaryllidaceae and amongst the largest plant genera in the world. Many of the species are edible, and some have a long history of cultivation and human consumption as a vegetable... | Allium | Wikipedia | 395 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
Various Allium species have been cultivated from the earliest times. About a dozen species are economically important as crops, or garden vegetables, and an increasing number of species are important as ornamental plants. Plants of the genus produce chemical compounds, mostly derived from cysteine sulfoxides, that give... | Allium | Wikipedia | 497 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
The terete or flattened flowering scapes are normally persistent. The inflorescences are umbels, in which the outside flowers bloom first and flowering progresses to the inside. Some species produce bulbils within the umbels, and in some species, such as Allium paradoxum, the bulbils replace some or all the flowers. Th... | Allium | Wikipedia | 450 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
Allium includes a number of taxonomic groupings previously considered separate genera (Caloscordum Herb., Milula Prain and Nectaroscordum Lindl.) Allium spicatum had been treated by many authors as Milula spicata, the only species in the monospecific genus Milula. In 2000, it was shown to be embedded in Allium.
Phylog... | Allium | Wikipedia | 509 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
The major evolutionary lineages or lines correspond to the three major clades. Line one (the oldest) with three subgenera is predominantly bulbous, the second, with five subgenera and the third with seven subgenera contain both bulbous and rhizomatous taxa.
Evolutionary lines and subgenera
The three evolutionary lin... | Allium | Wikipedia | 102 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
Evolutionary lines and subgenera (number of sections/number of species)
First evolutionary line (3 subgenera)
Nectaroscordum (Lindl.) Asch. et Graebn Type: Allium siculum (1/3) Mediterranean bells, Sicilian honey garlic
Microscordum (Maxim.) N. Friesen Type: Allium monanthum (1/1)
Amerallium Traub Type: Allium can... | Allium | Wikipedia | 429 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
First evolutionary line
Although this lineage consists of three subgenera, nearly all the species are attributed to subgenus Amerallium, the third largest subgenus of Allium. The lineage is considered to represent the most ancient line within Allium, and to be the only lineage that is purely bulbous, the other two hav... | Allium | Wikipedia | 336 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
Proposed infrageneric groups
Names from
Allium sect. Acanthoprason Wendelbo
Allium subsect. Acuminatae Ownbey ex Traub
Allium sect. Amerallium Traub
Allium sect. Anguinum G. Don
Allium sect. Brevispatha Vals.
Allium sect. Briseis Stearn
Allium sect. Bromatorrhiza Ekberg
Allium sect. Caloscordum Baker
Allium s... | Allium | Wikipedia | 456 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
The majority of Allium species are native to the Northern Hemisphere, being spread throughout the holarctic region, from dry subtropics to the boreal zone, predominantly in Asia. Of the latter, 138 species occur in China, about a sixth of all Allium species, representing five subgenera. A few species are native to Afri... | Allium | Wikipedia | 463 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
Ornamental
Many Allium species and hybrids are cultivated as ornamentals. These include A. cristophii and A. giganteum, which are used as border plants for their ornamental flowers, and their "architectural" qualities. Several hybrids have been bred, or selected, with rich purple flowers. A. hollandicum 'Purple Sensat... | Allium | Wikipedia | 413 | 47840567 | https://en.wikipedia.org/wiki/Allium | Biology and health sciences | Asparagales | Plants |
A leek is a vegetable, a cultivar of Allium ampeloprasum, the broadleaf wild leek (syn. Allium porrum). The edible part of the plant is a bundle of leaf sheaths that is sometimes erroneously called a stem or stalk. The genus Allium also contains the onion, garlic, shallot, scallion, chives, and Chinese onion. Three clo... | Leek | Wikipedia | 459 | 47840723 | https://en.wikipedia.org/wiki/Leek | Biology and health sciences | Monocots | null |
Varieties
Leek cultivars may be treated as a single cultivar group, e.g., as A. ampeloprasum 'Leek Group'. The cultivars can be subdivided in several ways, but the most common types are "summer leeks", intended for harvest in the season when planted, and overwintering leeks, meant to be harvested in the spring of the y... | Leek | Wikipedia | 283 | 47840723 | https://en.wikipedia.org/wiki/Leek | Biology and health sciences | Monocots | null |
Boiling turns it soft and mild in taste. Whole boiled leeks, served cold with vinaigrette, are popular in France, where leeks are nicknamed asperges du pauvre 'poor man's asparagus'.
Frying leaves it crunchier and preserves the taste.
Raw leeks can be used in salads, doing especially well when they are the prime ingr... | Leek | Wikipedia | 511 | 47840723 | https://en.wikipedia.org/wiki/Leek | Biology and health sciences | Monocots | null |
Historical consumption
The Hebrew Bible talks of , identified by commentators as leek, and says it is abundant in Egypt. Dried specimens from archaeological sites in ancient Egypt, as well as wall carvings and drawings, indicate that the leek was a part of the Egyptian diet from at least the second millennium BCE. Text... | Leek | Wikipedia | 509 | 47840723 | https://en.wikipedia.org/wiki/Leek | Biology and health sciences | Monocots | null |
Perhaps the most visible use of the leek, however, is as the cap badge of the Welsh Guards, a battalion within the Household Division of the British Army.
In Romania, the leek is also widely considered a symbol of Oltenia, a historical region in the country's southwestern part.
Gallery | Leek | Wikipedia | 62 | 47840723 | https://en.wikipedia.org/wiki/Leek | Biology and health sciences | Monocots | null |
The pound per square inch (abbreviation: psi) or, more accurately, pound-force per square inch (symbol: lbf/in2), is a unit of measurement of pressure or of stress based on avoirdupois units and used primarily in the United States. It is the pressure resulting from a force with magnitude of one pound-force applied to a... | Pound per square inch | Wikipedia | 406 | 23396816 | https://en.wikipedia.org/wiki/Pound%20per%20square%20inch | Physical sciences | Pressure | Basics and measurement |
Inch of water: 0.036 psid
Blood pressure – clinically normal human blood pressure (120/80 millimetre of mercury (mmHg): 2.32 psig/1.55 psig
Natural gas residential piped in for consumer appliance; 4–6 psig.
Boost pressure provided by an automotive turbocharger (common): 6–15 psig
NFL football: 12.5–13.5 psig
Atmos... | Pound per square inch | Wikipedia | 428 | 23396816 | https://en.wikipedia.org/wiki/Pound%20per%20square%20inch | Physical sciences | Pressure | Basics and measurement |
The Solanaceae (), or the nightshades, is a family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spices, weeds, and ornamentals. Many members of the family contain potent alkaloids, and some ... | Solanaceae | Wikipedia | 357 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
The genus Physalis produces the so-called groundcherries, as well as the tomatillo (Physalis philadelphica) and Physalis peruviana (Cape gooseberry). Alkekengi officinarum (Chinese Lantern) was previously included in the genus Physalis (as Physalis alkekengi), until molecular and genetic evidence placed it as the type ... | Solanaceae | Wikipedia | 399 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
Plants in the Solanaceae can take the form of herbs, shrubs, trees, vines and lianas, and sometimes epiphytes. They can be annuals, biennials, or perennials, upright or decumbent. Some have subterranean tubers. They do not have laticifers, nor latex, nor coloured saps.
They can have a basal or terminal group of leaves... | Solanaceae | Wikipedia | 252 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
The flowers are generally hermaphrodites, although some are monoecious, andromonoecious, or dioecious species (such as some Solanum or Symonanthus). Pollination is entomophilous. The flowers can be solitary or grouped into terminal, cymose, or axillary inflorescences. The flowers are medium-sized, fragrant (Nicotiana)... | Solanaceae | Wikipedia | 395 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
The androecium has (2)(4)5(6) free stamens within its opposite sepals (they alternate with the petals). They are usually fertile or, in some cases (for example in Salpiglossideae) they have staminodes. In the latter case, there is usually either one staminode (Salpiglossis) or three (Schizanthus). The anthers touch on ... | Solanaceae | Wikipedia | 211 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
The gynoecium is bicarpelar (rarely three- or five-locular) with a superior ovary and two locules, which may be secondarily divided by false septa, as is the case for Nicandreae and Datureae. The gynoecium is located in an oblique position relative to the flower's median plane. They have one style and one stigma; the l... | Solanaceae | Wikipedia | 436 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
Diversity of characteristics
Despite the previous description, the Solanaceae exhibit a large morphological variability, even in their reproductive characteristics. Examples of this diversity include:
The number of carpels that form the gynoecium
In general, the Solanaceae have a gynoecium (the female part of the fl... | Solanaceae | Wikipedia | 139 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
The number of locules in the ovary is usually the same as the number of carpels. However, some species occur in which the numbers are not the same due to the existence of false septa (internal walls that subdivide each locule), such as in Datura and some members of the Lycieae (the genera Grabowskia and Vassobia).
Ty... | Solanaceae | Wikipedia | 466 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
This subfamily is characterised by the presence of pericyclic fibres, an androecium with four or five stamens, frequently didynamous. The basic chromosome numbers are highly variable, from x=7 to x=13. The subfamily consists of eight genera (divided into three tribes) and about 195 species distributed throughout the Am... | Solanaceae | Wikipedia | 492 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
Anthocercideae G.Don: This tribe, endemic to Australia, contains 31 species in seven genera. Molecular phylogenetic studies of the tribe indicate it is the sister of Nicotiana, and the genera Anthocercis, Anthotroche, Grammosolen, and Symonanthus are monophyletic. Some characteristics are also thought to be derived fr... | Solanaceae | Wikipedia | 227 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
Molecular phylogenetics indicates that Petunioideae is the sister clade of the subfamilies with chromosome number x=12 (Solanoideae and Nicotianoideae). They contain calistegins, alkaloids similar to the tropanes. The androecium is formed of four stamens (rarely five), usually with two different lengths. The basic ch... | Solanaceae | Wikipedia | 427 | 47862520 | https://en.wikipedia.org/wiki/Solanaceae | Biology and health sciences | Solanales | null |
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