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Springs have been used for a variety of human needs - including drinking water, domestic water supply, irrigation, mills, navigation, and electricity generation. Modern uses include recreational activities such as fishing, swimming, and floating; therapy; water for livestock; fish hatcheries; and supply for bottled min... | Spring (hydrology) | Wikipedia | 492 | 316612 | https://en.wikipedia.org/wiki/Spring%20%28hydrology%29 | Physical sciences | Hydrology | null | vital_articles |
Bathing and balneotherapy
Hot springs or geothermal springs have been used for balneotherapy, bathing, and relaxation for thousands of years. Because of the folklore surrounding hot springs and their claimed medical value, some have become tourist destinations and locations of physical rehabilitation centers.
Geotherm... | Spring (hydrology) | Wikipedia | 475 | 316612 | https://en.wikipedia.org/wiki/Spring%20%28hydrology%29 | Physical sciences | Hydrology | null | vital_articles |
The 19th century Japanese artists Utagawa Hiroshige and Utagawa Toyokuni III created a series of wood-block prints, Two Artists Tour the Seven Hot Springs (Sōhitsu shichitō meguri) in 1854.
The Chinese city Jinan is known as "a City of Springs" (Chinese: 泉城), because of its 72 spring attractions and numerous micro spr... | Spring (hydrology) | Wikipedia | 83 | 316612 | https://en.wikipedia.org/wiki/Spring%20%28hydrology%29 | Physical sciences | Hydrology | null | vital_articles |
A spring is a device consisting of an elastic but largely rigid material (typically metal) bent or molded into a form (especially a coil) that can return into shape after being compressed or extended. Springs can store energy when compressed. In everyday use, the term most often refers to coil springs, but there are ma... | Spring (device) | Wikipedia | 434 | 316617 | https://en.wikipedia.org/wiki/Spring%20%28device%29 | Technology | Components_2 | null | vital_articles |
History
Simple non-coiled springs have been used throughout human history, e.g. the bow (and arrow). In the Bronze Age more sophisticated spring devices were used, as shown by the spread of tweezers in many cultures. Ctesibius of Alexandria developed a method for making springs out of an alloy of bronze with an increas... | Spring (device) | Wikipedia | 416 | 316617 | https://en.wikipedia.org/wiki/Spring%20%28device%29 | Technology | Components_2 | null | vital_articles |
Flat spring Made of a flat spring steel.
Machined spring Manufactured by machining bar stock with a lathe and/or milling operation rather than a coiling operation. Since it is machined, the spring may incorporate features in addition to the elastic element. Machined springs can be made in the typical load cases of com... | Spring (device) | Wikipedia | 126 | 316617 | https://en.wikipedia.org/wiki/Spring%20%28device%29 | Technology | Components_2 | null | vital_articles |
Cantilever spring A flat spring fixed only at one end like a cantilever, while the free-hanging end takes the load.
Coil spring Also known as a helical spring. A spring (made by winding a wire around a cylinder) is of two types:
Tension or extension springs are designed to become longer under load. Their turns (loops... | Spring (device) | Wikipedia | 461 | 316617 | https://en.wikipedia.org/wiki/Spring%20%28device%29 | Technology | Components_2 | null | vital_articles |
Belleville washer A disc shaped spring commonly used to apply tension to a bolt (and also in the initiation mechanism of pressure-activated landmines)
Constant-force spring A tightly rolled ribbon that exerts a nearly constant force as it is unrolled
Gas spring A volume of compressed gas.
Ideal spring An idealised p... | Spring (device) | Wikipedia | 501 | 316617 | https://en.wikipedia.org/wiki/Spring%20%28device%29 | Technology | Components_2 | null | vital_articles |
If made with constant pitch (wire thickness), conical springs have a variable rate. However, a conical spring can be made to have a constant rate by creating the spring with a variable pitch. A larger pitch in the larger-diameter coils and a smaller pitch in the smaller-diameter coils forces the spring to collapse or e... | Spring (device) | Wikipedia | 489 | 316617 | https://en.wikipedia.org/wiki/Spring%20%28device%29 | Technology | Components_2 | null | vital_articles |
Theory
In classical physics, a spring can be seen as a device that stores potential energy, specifically elastic potential energy, by straining the bonds between the atoms of an elastic material.
Hooke's law of elasticity states that the extension of an elastic rod (its distended length minus its relaxed length) is li... | Spring (device) | Wikipedia | 435 | 316617 | https://en.wikipedia.org/wiki/Spring%20%28device%29 | Technology | Components_2 | null | vital_articles |
Zero-length springs are made by manufacturing a coil spring with built-in tension (A twist is introduced into the wire as it is coiled during manufacture; this works because a coiled spring unwinds as it stretches), so if it could contract further, the equilibrium point of the spring, the point at which its restoring f... | Spring (device) | Wikipedia | 427 | 316617 | https://en.wikipedia.org/wiki/Spring%20%28device%29 | Technology | Components_2 | null | vital_articles |
In polymer chemistry, emulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomers, and surfactants. The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer (the oil) are emulsified (with surfactants) in ... | Emulsion polymerization | Wikipedia | 436 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
Advantages of emulsion polymerization include:
High molecular weight polymers can be made at fast polymerization rates. By contrast, in bulk and solution free-radical polymerization, there is a tradeoff between molecular weight and polymerization rate.
The continuous water phase is an excellent conductor of heat, enabl... | Emulsion polymerization | Wikipedia | 449 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
After World War II, emulsion polymerization was extended to production of plastics. Manufacture of dispersions to be used in latex paints and other products sold as liquid dispersions commenced. Ever more sophisticated processes were devised to prepare products that replaced solvent-based materials. Ironically, synthet... | Emulsion polymerization | Wikipedia | 192 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
The Smith-Ewart-Harkins theory for the mechanism of free-radical emulsion polymerization is summarized by the following steps:
A monomer is dispersed or emulsified in a solution of surfactant and water, forming relatively large droplets in water.
Excess surfactant creates micelles in the water.
Small amounts of mono... | Emulsion polymerization | Wikipedia | 432 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
High molecular weights are developed in emulsion polymerization because the concentration of growing chains within each polymer particle is very low. In conventional radical polymerization, the concentration of growing chains is higher, which leads to termination by coupling, which ultimately results in shorter polymer... | Emulsion polymerization | Wikipedia | 301 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
Interval 2
This interval is also known as steady state reaction stage. Throughout this stage, monomer droplets act as reservoirs supplying monomer to the growing polymer particles by diffusion through the water. While at steady state, the ratio of free radicals per particle can be divided into three cases. When the nu... | Emulsion polymerization | Wikipedia | 477 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
Process considerations
Emulsion polymerizations have been used in batch, semi-batch, and continuous processes. The choice depends on the properties desired in the final polymer or dispersion and on the economics of the product. Modern process control schemes have enabled the development of complex reaction processes, w... | Emulsion polymerization | Wikipedia | 449 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
Monomers
Typical monomers are those that undergo radical polymerization, are liquid or gaseous at reaction conditions, and are poorly soluble in water. Solid monomers are difficult to disperse in water. If monomer solubility is too high, particle formation may not occur and the reaction kinetics reduce to that of solut... | Emulsion polymerization | Wikipedia | 494 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
Surfactants
Selection of the correct surfactant is critical to the development of any emulsion polymerization process. The surfactant must enable a fast rate of polymerization, minimize coagulum or fouling in the reactor and other process equipment, prevent an unacceptably high viscosity during polymerization (which le... | Emulsion polymerization | Wikipedia | 485 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
Synthetic rubber
Some grades of styrene-butadiene (SBR)
Some grades of Polybutadiene
Polychloroprene (Neoprene)
Nitrile rubber
Acrylic rubber
Fluoroelastomer (FKM)
Plastics
Some grades of PVC
Some grades of polystyrene
Some grades of PMMA
Acrylonitrile-butadiene-styrene terpolymer (ABS)
Polyvinylidene fluoride
Polyviny... | Emulsion polymerization | Wikipedia | 164 | 316993 | https://en.wikipedia.org/wiki/Emulsion%20polymerization | Physical sciences | Organic reactions | Chemistry | vital_articles |
El Niño–Southern Oscillation (ENSO) is a global climate phenomenon that emerges from variations in winds and sea surface temperatures over the tropical Pacific Ocean. Those variations have an irregular pattern but do have some semblance of cycles. The occurrence of ENSO is not predictable. It affects the climate of muc... | El Niño–Southern Oscillation | Wikipedia | 420 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
El Niño and La Niña affect the global climate and disrupt normal weather patterns, which as a result can lead to intense storms in some places and droughts in others. El Niño events cause short-term (approximately 1 year in length) spikes in global average surface temperature while La Niña events cause short term surfa... | El Niño–Southern Oscillation | Wikipedia | 512 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
La Niña ("The Girl" in Spanish) is the colder counterpart of El Niño, as part of the broader ENSO climate pattern. In the past, it was also called an anti-El Niño and El Viejo, meaning "the old man."
A negative phase exists when atmospheric pressure over Indonesia and the west Pacific is abnormally high and pressure o... | El Niño–Southern Oscillation | Wikipedia | 383 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Cooler deep ocean water takes the place of the outgoing surface waters in the East Pacific, rising to the ocean surface in a process called upwelling. Along the western coast of South America, water near the ocean surface is pushed westward due to the combination of the trade winds and the Coriolis effect. This process... | El Niño–Southern Oscillation | Wikipedia | 451 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Bjerknes feedback
The close relationship between ocean temperatures and the strength of the trade winds was first identified by Jacob Bjerknes in 1969. Bjerknes also hypothesized that ENSO was a positive feedback system where the associated changes in one component of the climate system (the ocean or atmosphere) tend t... | El Niño–Southern Oscillation | Wikipedia | 493 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
The Southern Oscillation is the atmospheric component of ENSO. This component is an oscillation in surface air pressure between the tropical eastern and the western Pacific Ocean waters. The strength of the Southern Oscillation is measured by the Southern Oscillation Index (SOI). The SOI is computed from fluctuations i... | El Niño–Southern Oscillation | Wikipedia | 443 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Three phases of sea surface temperature
The El Niño–Southern Oscillation is a single climate phenomenon that quasi-periodically fluctuates between three phases: Neutral, La Niña or El Niño. La Niña and El Niño are opposite phases which require certain changes to take place in both the ocean and the atmosphere before a... | El Niño–Southern Oscillation | Wikipedia | 473 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
It is thought that there have been at least 30 El Niño events between 1900 and 2024, with the 1982–83, 1997–98 and 2014–16 events among the strongest on record. Since 2000, El Niño events have been observed in 2002–03, 2004–05, 2006–07, 2009–10, 2014–16, 2018–19, and 2023–24.
Major ENSO events were recorded in the yea... | El Niño–Southern Oscillation | Wikipedia | 492 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Transitional phases
Transitional phases at the onset or departure of El Niño or La Niña can also be important factors on global weather by affecting teleconnections. Significant episodes, known as Trans-Niño, are measured by the Trans-Niño index (TNI). Examples of affected short-time climate in North America include p... | El Niño–Southern Oscillation | Wikipedia | 508 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
The recent discovery of ENSO Modoki has some scientists believing it to be linked to global warming. However, comprehensive satellite data go back only to 1979. More research must be done to find the correlation and study past El Niño episodes. More generally, there is no scientific consensus on how/if climate change m... | El Niño–Southern Oscillation | Wikipedia | 512 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Monitoring and declaration of conditions
Currently, each country has a different threshold for what constitutes an El Niño event, which is tailored to their specific interests, for example:
In the United States, an El Niño is declared when the Climate Prediction Center, which monitors the sea surface temperatures ... | El Niño–Southern Oscillation | Wikipedia | 490 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Climate change
There is no sign that there are actual changes in the ENSO physical phenomenon due to climate change. Climate models do not simulate ENSO well enough to make reliable predictions. Future trends in ENSO are uncertain as different models make different predictions. It may be that the observed phenomenon o... | El Niño–Southern Oscillation | Wikipedia | 512 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Investigations regarding tipping points
The ENSO is considered to be a potential tipping element in Earth's climate. Global warming can strengthen the ENSO teleconnection and resulting extreme weather events. For example, an increase in the frequency and magnitude of El Niño events have triggered warmer than usual temp... | El Niño–Southern Oscillation | Wikipedia | 279 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Over the Atlantic Ocean, vertical wind shear is increased, which inhibits tropical cyclone genesis and intensification, by causing the westerly winds to be stronger. The atmosphere over the Atlantic Ocean can also be drier and more stable during El Niño events, which can inhibit tropical cyclone genesis and intensific... | El Niño–Southern Oscillation | Wikipedia | 416 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
When El Niño conditions last for many months, extensive ocean warming and the reduction in easterly trade winds limits upwelling of cold nutrient-rich deep water, and its economic effect on local fishing for an international market can be serious. Developing countries that depend on their own agriculture and fishing, p... | El Niño–Southern Oscillation | Wikipedia | 476 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
ENSO conditions have also been related to Kawasaki disease incidence in Japan and the west coast of the United States, via the linkage to tropospheric winds across the north Pacific Ocean.
ENSO may be linked to civil conflicts. Scientists at The Earth Institute of Columbia University, having analyzed data from 1950 to... | El Niño–Southern Oscillation | Wikipedia | 358 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Most critically, global mass bleaching events were recorded in 1997-98 and 2015–16, when around 75-99% losses of live coral were registered across the world. Considerable attention was also given to the collapse of Peruvian and Chilean anchovy populations that led to a severe fishery crisis following the ENSO events in... | El Niño–Southern Oscillation | Wikipedia | 492 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Antarctica
Many ENSO linkages exist in the high southern latitudes around Antarctica. Specifically, El Niño conditions result in high-pressure anomalies over the Amundsen and Bellingshausen Seas, causing reduced sea ice and increased poleward heat fluxes in these sectors, as well as the Ross Sea. The Weddell Sea, conv... | El Niño–Southern Oscillation | Wikipedia | 499 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Europe
El Niño's effects on Europe are controversial, complex and difficult to analyze, as it is one of several factors that influence the weather over the continent and other factors can overwhelm the signal.
North America
La Niña causes mostly the opposite effects of El Niño: above-average precipitation across th... | El Niño–Southern Oscillation | Wikipedia | 481 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
To the north across Alaska, La Niña events lead to drier than normal conditions, while El Niño events do not have a correlation towards dry or wet conditions. During El Niño events, increased precipitation is expected in California due to a more southerly, zonal, storm track. During La Niña, increased precipitation is ... | El Niño–Southern Oscillation | Wikipedia | 481 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Fiji generally experiences drier than normal conditions during an El Niño, which can lead to drought becoming established over the Islands. However, the main impacts on the island nation is felt about a year after the event becomes established. Within the Samoan Islands, below average rainfall and higher than normal te... | El Niño–Southern Oscillation | Wikipedia | 419 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
The local fishing industry along the affected coastline can suffer during long-lasting El Niño events. Peruvian fisheries collapsed during the 1970s due to overfishing following the 1972 El Niño Peruvian anchoveta reduction. The fisheries were previously the world's largest, however, this collapse led to the decline of... | El Niño–Southern Oscillation | Wikipedia | 358 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
Galápagos Islands
The Galápagos Islands are a chain of volcanic islands, nearly 600 miles west of Ecuador, South America. in the Eastern Pacific Ocean. These islands support a wide diversity of terrestrial and marine species. The ecosystem is based on the normal trade winds which influence upwelling of cold, nutrient ... | El Niño–Southern Oscillation | Wikipedia | 504 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
The phenomenon had long been of interest because of its effects on the guano industry and other enterprises that depend on biological productivity of the sea. It is recorded that as early as 1822, cartographer Joseph Lartigue, of the French frigate La Clorinde under Baron Mackau, noted the "counter-current" and its use... | El Niño–Southern Oscillation | Wikipedia | 371 | 317311 | https://en.wikipedia.org/wiki/El%20Ni%C3%B1o%E2%80%93Southern%20Oscillation | Physical sciences | Climatology | null | vital_articles |
In an automobile, ball joints are spherical bearings that connect the control arms to the steering knuckles, and are used on virtually every automobile made. They bionically resemble the ball-and-socket joints found in most tetrapod animals.
A ball joint consists of a bearing stud and socket enclosed in a casing; all... | Ball joint | Wikipedia | 505 | 4069796 | https://en.wikipedia.org/wiki/Ball%20joint | Technology | Mechanisms | null | vital_articles |
The introduction of ball joints top and bottom allowed 3-axis articulation and so removed all the constraints on the control arm axes being exactly parallel, so caster could be freely adjusted, typically by asymmetric adjustment of the position of the control arm inner pivots, while camber was adjusted by the symmetric... | Ball joint | Wikipedia | 470 | 4069796 | https://en.wikipedia.org/wiki/Ball%20joint | Technology | Mechanisms | null | vital_articles |
In non-MacPherson strut automobile suspension, the two ball joints are called the "upper ball joint" and "lower ball joint". Lower ball joints are sometimes larger and may wear out faster, because the fore and aft loads, primarily due to braking, are higher at the bottom ball joint. (Torque reaction and drag add at the... | Ball joint | Wikipedia | 431 | 4069796 | https://en.wikipedia.org/wiki/Ball%20joint | Technology | Mechanisms | null | vital_articles |
Front-wheel drive
Unlike a kingpin, which requires an assembly in the center of the wheel in order to pivot, joints connect to the upper and lower end of the spindle (steering knuckle), to the control arms. This leaves the center section open to allow the use of front-wheel drive. Older kingpin designs can only be us... | Ball joint | Wikipedia | 498 | 4069796 | https://en.wikipedia.org/wiki/Ball%20joint | Technology | Mechanisms | null | vital_articles |
An alternative to the SRJ is the universal joint, which consists of two revolute joints. By using spherical rolling joints instead of universal, designers can reduce the number of joints to achieve the same result. Using a spherical joint as opposed to a universal joint also eliminates the problematic possibility of a... | Ball joint | Wikipedia | 431 | 4069796 | https://en.wikipedia.org/wiki/Ball%20joint | Technology | Mechanisms | null | vital_articles |
A conveyor system is a common piece of mechanical handling equipment that moves materials from one location to another. Conveyors are especially useful in applications involving the transport of heavy or bulky materials. Conveyor systems allow quick and efficient transport for a wide variety of materials, which make th... | Conveyor system | Wikipedia | 512 | 13215001 | https://en.wikipedia.org/wiki/Conveyor%20system | Technology | Industry: General | null | vital_articles |
Increasing the service life of a conveyor system involves: choosing the right conveyor type, the right system design and paying attention to regular maintenance practices.
A conveyor system that is designed properly will last a long time with proper maintenance. Overhead conveyor systems have been used in numerous app... | Conveyor system | Wikipedia | 416 | 13215001 | https://en.wikipedia.org/wiki/Conveyor%20system | Technology | Industry: General | null | vital_articles |
Pneumatic
Every pneumatic system uses pipes or ducts called transport lines that carry a mixture of materials and a stream of air. These materials are free flowing powdery materials like cement and fly ash. Products are moved through tubes by air pressure. Pneumatic conveyors are either carrier systems or dilute-phase ... | Conveyor system | Wikipedia | 449 | 13215001 | https://en.wikipedia.org/wiki/Conveyor%20system | Technology | Industry: General | null | vital_articles |
Flexible
The flexible conveyor is based on a conveyor beam in aluminum or stainless steel, with low-friction slide rails guiding a plastic multi-flexing chain. Products to be conveyed travel directly on the conveyor, or on pallets/carriers. These conveyors can be worked around obstacles and keep production lines flowin... | Conveyor system | Wikipedia | 496 | 13215001 | https://en.wikipedia.org/wiki/Conveyor%20system | Technology | Industry: General | null | vital_articles |
Like spiral conveyors, vertical conveyors that use forks can transport material loads in a continuous flow. With these forks the load can be taken from one horizontal conveyor and put down on another horizontal conveyor on a different level. By adding more forks, more products can be lifted at the same time. Convention... | Conveyor system | Wikipedia | 496 | 13215001 | https://en.wikipedia.org/wiki/Conveyor%20system | Technology | Industry: General | null | vital_articles |
Chain-driven live roller conveyors are used for single or bi-directional material handling. Large, heavy loads are moved by chain driven live roller conveyors.
Pallet accumulation conveyors are powered through a mechanical clutch. This is used instead of individually powered and controlled sections of conveyors.
Mult... | Conveyor system | Wikipedia | 314 | 13215001 | https://en.wikipedia.org/wiki/Conveyor%20system | Technology | Industry: General | null | vital_articles |
Roman concrete, also called , was used in construction in ancient Rome. Like its modern equivalent, Roman concrete was based on a hydraulic-setting cement added to an aggregate.
Many buildings and structures still standing today, such as bridges, reservoirs and aqueducts, were built with this material, which attests ... | Roman concrete | Wikipedia | 470 | 13222289 | https://en.wikipedia.org/wiki/Roman%20concrete | Technology | Building materials | null | vital_articles |
For rebuilding Rome after the fire in 64 AD which destroyed large portions of the city, Nero's new building code largely called for brick-faced concrete. This appears to have encouraged the development of the brick and concrete industries.
Material properties
Roman concrete, like any concrete, consists of an aggregate... | Roman concrete | Wikipedia | 470 | 13222289 | https://en.wikipedia.org/wiki/Roman%20concrete | Technology | Building materials | null | vital_articles |
The strength and longevity of Roman 'marine' concrete is understood to benefit from a reaction of seawater with a mixture of volcanic ash and quicklime to create a rare crystal called tobermorite, which may resist fracturing. As seawater percolated within the tiny cracks in the Roman concrete, it reacted with phillipsi... | Roman concrete | Wikipedia | 329 | 13222289 | https://en.wikipedia.org/wiki/Roman%20concrete | Technology | Building materials | null | vital_articles |
Modern use
Scientific studies of Roman concrete since 2010 have attracted both media and industry attention. Because of its unusual durability, longevity, and lessened environmental footprint, corporations and municipalities are starting to explore the use of Roman-style concrete in North America. This involves replaci... | Roman concrete | Wikipedia | 228 | 13222289 | https://en.wikipedia.org/wiki/Roman%20concrete | Technology | Building materials | null | vital_articles |
Pastoralism is a form of animal husbandry where domesticated animals (known as "livestock") are released onto large vegetated outdoor lands (pastures) for grazing, historically by nomadic people who moved around with their herds. The animal species involved include cattle, camels, goats, yaks, llamas, reindeer, horses... | Pastoralism | Wikipedia | 436 | 966760 | https://en.wikipedia.org/wiki/Pastoralism | Technology | Agriculture_2 | null | vital_articles |
Pastoralist herds interact with their environment, and mediate human relations with the environment as a way of turning uncultivated plants (like wild grass) into food. In many places, grazing herds on savannas and in woodlands can help maintain the biodiversity of such landscapes and prevent them from evolving into de... | Pastoralism | Wikipedia | 486 | 966760 | https://en.wikipedia.org/wiki/Pastoralism | Technology | Agriculture_2 | null | vital_articles |
Pastoralists do not exist at basic subsistence. Pastoralists often compile wealth and participate in international trade. Pastoralists have trade relations with agriculturalists, horticulturalists, and other groups. Pastoralists are not extensively dependent on milk, blood, and meat of their herd. McCabe noted that whe... | Pastoralism | Wikipedia | 504 | 966760 | https://en.wikipedia.org/wiki/Pastoralism | Technology | Agriculture_2 | null | vital_articles |
Pastoralist strategies typify effective adaptation to the environment. Precipitation differences are evaluated by pastoralists. In East Africa, different animals are taken to specific regions throughout the year that corresponds to the seasonal patterns of precipitation. Transhumance is the migration of livestock and p... | Pastoralism | Wikipedia | 500 | 966760 | https://en.wikipedia.org/wiki/Pastoralism | Technology | Agriculture_2 | null | vital_articles |
The flexibility of pastoralists to respond to environmental change was reduced by colonization. For example, mobility was limited in the Sahel region of Africa with settlement being encouraged. The population tripled and sanitation and medical treatment were improved.
Environment knowledge
Pastoralists have mental ma... | Pastoralism | Wikipedia | 414 | 966760 | https://en.wikipedia.org/wiki/Pastoralism | Technology | Agriculture_2 | null | vital_articles |
There is a variation in genetic makeup of the farm animals driven mainly by natural and human based selection. For example, pastoralists in large parts of Sub Saharan Africa are preferring livestock breeds which are adapted to their environment and able to tolerate drought and diseases. However, in other animal product... | Pastoralism | Wikipedia | 479 | 966760 | https://en.wikipedia.org/wiki/Pastoralism | Technology | Agriculture_2 | null | vital_articles |
The violent herder–farmer conflicts in Nigeria, Mali, Sudan, Ethiopia and other countries in the Sahel and Horn of Africa regions have been exacerbated by climate change, land degradation, and population growth.
It has also been shown that pastoralism supports human existence in harsh environments and often represents... | Pastoralism | Wikipedia | 68 | 966760 | https://en.wikipedia.org/wiki/Pastoralism | Technology | Agriculture_2 | null | vital_articles |
Messier 77 (M77), also known as NGC 1068 or the Squid Galaxy, is a barred spiral galaxy in the constellation Cetus. It is about away from Earth, and was discovered by Pierre Méchain in 1780, who originally described it as a nebula. Méchain then communicated his discovery to Charles Messier, who subsequently listed th... | Messier 77 | Wikipedia | 474 | 967488 | https://en.wikipedia.org/wiki/Messier%2077 | Physical sciences | Notable galaxies | Astronomy | vital_articles |
In February 2022 astronomers reported a cloud of cosmic dust, detected through infrared interferometry observations, located at the centre of Messier 77 that is hiding a supermassive black hole.
In November 2022, the IceCube collaboration announced the detection of a neutrino source emitted by the active galactic nucl... | Messier 77 | Wikipedia | 107 | 967488 | https://en.wikipedia.org/wiki/Messier%2077 | Physical sciences | Notable galaxies | Astronomy | vital_articles |
The pumpkinseed (Lepomis gibbosus), also referred to as sun perch, pond perch, common sunfish, punkie, sunfish, sunny, and kivver, is a small to medium–sized freshwater fish of the genus Lepomis (true sunfishes), from the sunfish family (Centrarchidae) in the order Centrarchiformes. It is endemic to eastern North Ameri... | Pumpkinseed | Wikipedia | 347 | 967508 | https://en.wikipedia.org/wiki/Pumpkinseed | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
Pumpkinseeds have a body shaped much like a pumpkin seed (thus the common name), typically about but up to in length. They typically weigh less than , with the world record being caught by Robert Warne while fishing Honeoye Lake, Upstate New York in 2016. They are orange, green, yellow or blue in color, with speckle... | Pumpkinseed | Wikipedia | 506 | 967508 | https://en.wikipedia.org/wiki/Pumpkinseed | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
Dietary habits
Pumpkinseeds are carnivorous and feed on a variety of small prey both at the water surface and at the bottom. Among their favorites are insects, small molluscs and crustaceans (such as small crawfish), worms, minnow fry, small frogs or tadpoles, and even cannibalizing other smaller pumpkinseeds. They ar... | Pumpkinseed | Wikipedia | 453 | 967508 | https://en.wikipedia.org/wiki/Pumpkinseed | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
Conservation status
The pumpkinseed sunfish is very common and is not listed by CITES. It is considered Least Concern (not threatened) by the IUCN. Spawning grounds of the pumpkinseeds can be disturbed by shoreline development and shoreline erosion from heavy lake use. Their susceptibility to silt and pollution makes ... | Pumpkinseed | Wikipedia | 503 | 967508 | https://en.wikipedia.org/wiki/Pumpkinseed | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
The pumpkinseed sunfish has developed a specific method of protection. Along the dorsal fin are 10 to 11 spines, and three additional spines on the anal fin. These spines are very sharp, which aid the fish in defense. The pumpkinseed has the ability to anticipate approaching predators (or prey) via a lateral line syste... | Pumpkinseed | Wikipedia | 364 | 967508 | https://en.wikipedia.org/wiki/Pumpkinseed | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
The cookiecutter shark (Isistius brasiliensis), also called the cigar shark, is a species of small squaliform shark in the family Dalatiidae. This shark lives in warm, oceanic waters worldwide, particularly near islands, and has been recorded as deep as . It migrates vertically up to every day, approaching the surface... | Cookiecutter shark | Wikipedia | 423 | 969122 | https://en.wikipedia.org/wiki/Cookiecutter%20shark | Biology and health sciences | Sharks | Animals | vital_articles |
Taxonomy
French naturalists Jean René Constant Quoy and Joseph Paul Gaimard originally described the cookiecutter shark during the 1817–1820 exploratory voyage of the corvette Uranie under Louis de Freycinet, giving it the name Scymnus brasiliensis because the type specimen was caught off Brazil. In 1824, their account... | Cookiecutter shark | Wikipedia | 411 | 969122 | https://en.wikipedia.org/wiki/Cookiecutter%20shark | Biology and health sciences | Sharks | Animals | vital_articles |
The mouth is short, forming a nearly transverse line, and is surrounded by enlarged, fleshy, suctorial lips. The upper jaw has 30–37 rows of teeth, and the lower jaw has 25–31, increasing with body size. The upper and lower teeth are extremely different; the upper teeth are small, narrow, and upright, tapering to a sin... | Cookiecutter shark | Wikipedia | 341 | 969122 | https://en.wikipedia.org/wiki/Cookiecutter%20shark | Biology and health sciences | Sharks | Animals | vital_articles |
Distribution and habitat
Inhabiting all of the world's major tropical and warm-temperate oceanic basins, the cookiecutter shark is most common between the latitudes of 20°N and 20°S, where the surface water temperature is . In the Atlantic, it has been reported off the Bahamas and southern Brazil in the west, Cape Verd... | Cookiecutter shark | Wikipedia | 329 | 969122 | https://en.wikipedia.org/wiki/Cookiecutter%20shark | Biology and health sciences | Sharks | Animals | vital_articles |
Best known for biting neat round chunks of tissue from marine mammals and large fish, the cookiecutter shark is considered a facultative ectoparasite, as it also wholly ingests smaller prey. It has a wide gape and a very strong bite, by virtue of heavily calcified cranial and labial cartilages. With small fins and weak... | Cookiecutter shark | Wikipedia | 488 | 969122 | https://en.wikipedia.org/wiki/Cookiecutter%20shark | Biology and health sciences | Sharks | Animals | vital_articles |
Set apart from the glowing underside, the darker, nonluminescent collar tapers at both sides of the throat, and has been hypothesized to serve as a lure by mimicking the silhouette of a small fish from below. The appeal of the lure would be multiplied in a school of sharks. If the collar does function in this way, the ... | Cookiecutter shark | Wikipedia | 489 | 969122 | https://en.wikipedia.org/wiki/Cookiecutter%20shark | Biology and health sciences | Sharks | Animals | vital_articles |
The cookiecutter shark exhibits a number of specializations to its mouth and pharynx for its parasitic lifestyle. The shark first secures itself to the body surface of its prey by closing its spiracles and retracting its basihyal (tongue) to create pressure lower than that of the surroundings; its suctorial lips ensure... | Cookiecutter shark | Wikipedia | 330 | 969122 | https://en.wikipedia.org/wiki/Cookiecutter%20shark | Biology and health sciences | Sharks | Animals | vital_articles |
Favoring offshore waters and thus seldom encountered by humans, the cookiecutter shark is not considered dangerous because of its small size. However, it has been implicated in a few attacks on humans; in one case, a school of 30-cm (12 in) long fish with blunt snouts attacked an underwater photographer on an open-ocea... | Cookiecutter shark | Wikipedia | 410 | 969122 | https://en.wikipedia.org/wiki/Cookiecutter%20shark | Biology and health sciences | Sharks | Animals | vital_articles |
During the 1970s, several U.S. Navy submarines were forced back to base to repair damage caused by cookiecutter shark bites to the neoprene boots of their AN/BQR-19 sonar domes, which caused the sound-transmitting oil inside to leak and impaired navigation. An unknown enemy weapon was initially feared, before this shar... | Cookiecutter shark | Wikipedia | 295 | 969122 | https://en.wikipedia.org/wiki/Cookiecutter%20shark | Biology and health sciences | Sharks | Animals | vital_articles |
Protein structure is the three-dimensional arrangement of atoms in an amino acid-chain molecule. Proteins are polymers specifically polypeptides formed from sequences of amino acids, which are the monomers of the polymer. A single amino acid monomer may also be called a residue, which indicates a repeating unit of a p... | Protein structure | Wikipedia | 363 | 969126 | https://en.wikipedia.org/wiki/Protein%20structure | Biology and health sciences | Proteins | Biology | vital_articles |
The primary structure of a protein refers to the sequence of amino acids in the polypeptide chain. The primary structure is held together by peptide bonds that are made during the process of protein biosynthesis. The two ends of the polypeptide chain are referred to as the carboxyl terminus (C-terminus) and the amino t... | Protein structure | Wikipedia | 365 | 969126 | https://en.wikipedia.org/wiki/Protein%20structure | Biology and health sciences | Proteins | Biology | vital_articles |
Secondary structure refers to highly regular local sub-structures on the actual polypeptide backbone chain. Two main types of secondary structure, the α-helix and the β-strand or β-sheets, were suggested in 1951 by Linus Pauling. These secondary structures are defined by patterns of hydrogen bonds between the main-chai... | Protein structure | Wikipedia | 336 | 969126 | https://en.wikipedia.org/wiki/Protein%20structure | Biology and health sciences | Proteins | Biology | vital_articles |
Quaternary structure is the three-dimensional structure consisting of the aggregation of two or more individual polypeptide chains (subunits) that operate as a single functional unit (multimer). The resulting multimer is stabilized by the same non-covalent interactions and disulfide bonds as in tertiary structure. Ther... | Protein structure | Wikipedia | 442 | 969126 | https://en.wikipedia.org/wiki/Protein%20structure | Biology and health sciences | Proteins | Biology | vital_articles |
Structural domain
A structural domain is an element of the protein's overall structure that is self-stabilizing and often folds independently of the rest of the protein chain. Many domains are not unique to the protein products of one gene or one gene family but instead appear in a variety of proteins. Domains often ar... | Protein structure | Wikipedia | 321 | 969126 | https://en.wikipedia.org/wiki/Protein%20structure | Biology and health sciences | Proteins | Biology | vital_articles |
Proteins are not static objects, but rather populate ensembles of conformational states. Transitions between these states typically occur on nanoscales, and have been linked to functionally relevant phenomena such as allosteric signaling and enzyme catalysis. Protein dynamics and conformational changes allow proteins... | Protein structure | Wikipedia | 343 | 969126 | https://en.wikipedia.org/wiki/Protein%20structure | Biology and health sciences | Proteins | Biology | vital_articles |
Protein ensemble files are a representation of a protein that can be considered to have a flexible structure. Creating these files requires determining which of the various theoretically possible protein conformations actually exist. One approach is to apply computational algorithms to the protein data in order to try ... | Protein structure | Wikipedia | 492 | 969126 | https://en.wikipedia.org/wiki/Protein%20structure | Biology and health sciences | Proteins | Biology | vital_articles |
Around 90% of the protein structures available in the Protein Data Bank have been determined by X-ray crystallography. This method allows one to measure the three-dimensional (3-D) density distribution of electrons in the protein, in the crystallized state, and thereby infer the 3-D coordinates of all the atoms to be d... | Protein structure | Wikipedia | 320 | 969126 | https://en.wikipedia.org/wiki/Protein%20structure | Biology and health sciences | Proteins | Biology | vital_articles |
Protein structure databases
A protein structure database is a database that is modeled around the various experimentally determined protein structures. The aim of most protein structure databases is to organize and annotate the protein structures, providing the biological community access to the experimental data in a ... | Protein structure | Wikipedia | 489 | 969126 | https://en.wikipedia.org/wiki/Protein%20structure | Biology and health sciences | Proteins | Biology | vital_articles |
A herd is a social group of certain animals of the same species, either wild or domestic. The form of collective animal behavior associated with this is called herding. These animals are known as gregarious animals.
The term herd is generally applied to mammals, and most particularly to the grazing ungulates that clas... | Herd | Wikipedia | 421 | 969684 | https://en.wikipedia.org/wiki/Herd | Biology and health sciences | Ethology | Biology | vital_articles |
A herd is, by definition, relatively unstructured. However, there may be two or a few animals which tend to be imitated by the bulk of the herd more than others. An animal in this role is called a "control animal", since its behaviour will predict that of the herd as a whole. It cannot be assumed, however, that the con... | Herd | Wikipedia | 506 | 969684 | https://en.wikipedia.org/wiki/Herd | Biology and health sciences | Ethology | Biology | vital_articles |
The effect of collective vigilance in social groups has been widely studied within the framework of optimal foraging theory and animal decision making. While animals under the risk of predation are feeding or resting, they have to stay vigilant and watch for predators. It could be shown in many studies (especially for ... | Herd | Wikipedia | 348 | 969684 | https://en.wikipedia.org/wiki/Herd | Biology and health sciences | Ethology | Biology | vital_articles |
Foraging
Hunting together enables group-living predators, such as wolves and wild dogs, to catch large prey, which they are unable to achieve when hunting alone. Working together significantly improves foraging efficiency, meaning the net energy gain of each individual is increased when animals are feeding collectively... | Herd | Wikipedia | 498 | 969684 | https://en.wikipedia.org/wiki/Herd | Biology and health sciences | Ethology | Biology | vital_articles |
Diseases and parasites
Since animals in groups stay near each other and interact frequently, infectious diseases and parasites spread much easier between them compared to solitary animals. Studies have shown a positive correlation between herd size and intensity of infections, but the extent to which this sometimes dra... | Herd | Wikipedia | 422 | 969684 | https://en.wikipedia.org/wiki/Herd | Biology and health sciences | Ethology | Biology | vital_articles |
The term has acquired a semi-technical usage in behavioral finance to describe the largest group of market investors or market speculators who tend to "move with the market", or "follow the general market trend". This is at least a plausible example of genuine herding, though according to some researchers it results fr... | Herd | Wikipedia | 127 | 969684 | https://en.wikipedia.org/wiki/Herd | Biology and health sciences | Ethology | Biology | vital_articles |
The common toad, European toad, or in Anglophone parts of Europe, simply the toad (Bufo bufo, from Latin bufo "toad"), is a toad found throughout most of Europe (with the exception of Ireland, Iceland, parts of Scandinavia, and some Mediterranean islands), in the western part of North Asia, and in a small portion of No... | Common toad | Wikipedia | 455 | 969943 | https://en.wikipedia.org/wiki/Common%20toad | Biology and health sciences | Frogs and toads | Animals | vital_articles |
Various subspecies of B. bufo have been recognized over the years. The Caucasian toad is found in the mountainous regions of the Caucasus and was at one time classified as B. b. verrucosissima. It has a larger genome and differs from B. bufo morphologically and is now accepted as Bufo verrucosissimus. The spiny toad wa... | Common toad | Wikipedia | 414 | 969943 | https://en.wikipedia.org/wiki/Common%20toad | Biology and health sciences | Frogs and toads | Animals | vital_articles |
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