• Mathematically: p = − F A , {\displaystyle p=-{\frac {F}{A}},} where: p {\displaystyle p} is the pressure, F {\displaystyle F} is the magnitude of the normal force, A {\displaystyle A} is the area of the surface on contact. (wikipedia.org)
  • The pressure is the scalar proportionality constant that relates the two normal vectors: d F n = − p d A = − p n d A . {\displaystyle d\mathbf {F} _{n}=-p\,d\mathbf {A} =-p\,\mathbf {n} \,dA. (wikipedia.org)
  • If K is the equilibrium constant and P is the pressure then the volume change is given by: Δ V o = − R T ( ∂ ln ⁡ K ∂ P ) T {\displaystyle \Delta V^{o}=-RT\left({\frac {\partial \ln K}{\partial P}}\right)_{T}} where R is the universal gas constant and T is the absolute temperature. (wikipedia.org)
  • is the fluid density v {\displaystyle v} is the speed of fluid P static {\displaystyle P_{\text{static}}} is the static pressure at any point. (wikipedia.org)
  • In fluid statics, capillary pressure ( p c {\displaystyle {p_{c}}} ) is the pressure between two immiscible fluids in a thin tube (see capillary), resulting from the interactions of forces between the fluids and solid walls of the tube. (wikipedia.org)
  • φ p , 0 {\displaystyle \varphi _{p,0}} is the phase shift of the acoustic pressure. (wikipedia.org)
  • A common example of use is finding the pressure inside an air bubble in pure water, where γ {\displaystyle \gamma } = 72 mN/m at 25 °C (298 K). The extra pressure inside the bubble is given here for three bubble sizes: A 1 mm bubble has negligible extra pressure. (wikipedia.org)
  • The same calculation can be done for small oil droplets in water, where even in the presence of surfactants and a fairly low interfacial tension γ {\displaystyle \gamma } = 5-10 mN/m, the pressure inside 100 nm diameter droplets can reach several atmospheres. (wikipedia.org)
  • For example, given an ideal gas mixture of nitrogen (N2), hydrogen (H2) and ammonia (NH3): p = p N 2 + p H 2 + p NH 3 {\displaystyle p=p_{{\ce {N2}}}+p_{{\ce {H2}}}+p_{{\ce {NH3}}}} Ideally the ratio of partial pressures equals the ratio of the number of molecules. (wikipedia.org)
  • Therefore, dividing the magnitude of Casimir force by the area of each conductor, Casimir pressure P {\displaystyle P} can be found. (wikipedia.org)
  • If the variation in height above the datum is zero, or so small it can be ignored, the above equation reduces to the following simplified form: p 0 = p + q {\displaystyle p_{0}=p+q\,} Because this is the static pressure that occurs in locations where the fluid flow is entirely stopped (stagnated), this case is also called the stagnation pressure. (wikipedia.org)
  • The maximum pressure is: P m a x = 4 F L D × 1 − cos ⁡ θ 0 2 θ 0 − sin ⁡ 2 θ 0 {\displaystyle P_{\mathrm {max} }={\frac {4F}{LD}}\times {\frac {1-\cos \theta _{0}}{2\theta _{0}-\sin 2\theta _{0}}}} the angle θ0 is in radians. (wikipedia.org)
  • The overburden pressure at a depth z is given by p ( z ) = p 0 + g ∫ 0 z ρ ( z ) d z {\displaystyle p(z)=p_{0}+g\int _{0}^{z}\rho (z)\,dz} where ρ(z) is the density of the overlying rock at depth z and g is the acceleration due to gravity. (wikipedia.org)
  • In incompressible fluid dynamics dynamic pressure (indicated with q, or Q, and sometimes called velocity pressure) is the quantity defined by: q = 1 2 ρ u 2 , {\displaystyle q={\tfrac {1}{2}}\,\rho \,u^{2},} where (using SI units): Dynamic pressure is the kinetic energy per unit volume of a fluid particle. (wikipedia.org)
  • We would normally use pressure head calculations in areas in which g {\displaystyle g} is constant. (wikipedia.org)
  • 0 {\displaystyle g>0} , we observe that the pressure head is also negative, and the ambient air is sucked into the columns shown in the venturi meter above. (wikipedia.org)
  • Jacobus van 't Hoff first proposed a "law" relating osmotic pressure to solute concentration Π = i M solute R T {\displaystyle \Pi =iM_{\text{solute}}RT} where Π {\displaystyle \Pi } is osmotic pressure, i is the dimensionless van't Hoff index that addresses solute that dissociates an frequently non-idealities, Msolutes is the molar concentration, R is the Ideal gas constant, and T is the temperature in kelvins. (wikipedia.org)
  • where: q {\displaystyle \;q} is dynamic pressure Dynamic pressure Pitot-static system Pressure Static pressure DoD and NATO definition of impact pressure Retrieved on 2008-10-01 The Free Dictionary Retrieved on 2008-10-01 L. J. Clancy (1975) Aerodynamics, Section 3.12 and 3.13 "the dynamic pressure is equal to half rho vee squared only in incompressible flow. (wikipedia.org)
  • C p {\displaystyle C_{p}} of zero indicates the pressure is the same as the free stream pressure. (wikipedia.org)
  • C p {\displaystyle C_{p}} of one corresponds to the stagnation pressure and indicates a stagnation point. (wikipedia.org)
  • C p {\displaystyle C_{p}} of minus one is significant in the design of gliders because this indicates a perfect location for a "Total energy" port for supply of signal pressure to the Variometer, a special Vertical Speed Indicator which reacts to vertical movements of the atmosphere but does not react to vertical maneuvering of the glider. (wikipedia.org)
  • In the flow of compressible fluids such as air, and particularly the high-speed flow of compressible fluids, ρ v 2 / 2 {\displaystyle {\rho v^{2}}/2} (the dynamic pressure) is no longer an accurate measure of the difference between stagnation pressure and static pressure. (wikipedia.org)
  • In this sense, more specifically, the cerebral perfusion pressure can be defined as either: C P P = M A P − I C P {\displaystyle CPP=MAP-ICP} (if ICP is higher than JVP) or C P P = M A P − J V P {\displaystyle CPP=MAP-JVP} (if JVP is higher than ICP). (wikipedia.org)
  • Pressure cooking is the process of cooking food, using water or other cooking liquid, in a sealed vessel known as a pressure cooker . (wikipedia.org)
  • Atmospheric-pressure plasmas have prominent technical significance because in contrast with low-pressure plasma or high-pressure plasma no reaction vessel is needed to ensure the maintenance of a pressure level differing from atmospheric pressure. (wikipedia.org)
  • Vessel - a housing designed and built to contain fluids under pressure. (hse.gov.uk)
  • After use, the pressure is slowly released so that the vessel can be opened safely. (wikipedia.org)
  • A Pressure Reactor, sometimes referred to as a pressure tube, or a sealed tube, is a chemical reaction vessel which can conduct a reaction under pressure. (wikipedia.org)
  • A pressure reactor is a special application of a pressure vessel. (wikipedia.org)
  • However, pressure can speed up the desired reaction and only impacts decomposition when it involves the release of a gas or a reaction with a gas in the vessel. (wikipedia.org)
  • If a pressure reactor is engineered properly, it can meet 4 out of 12 green chemistry principles 1, less solvent and cleaner reaction profile result in less waste 5, less solvent is needed 6, short reaction time can save up to 92 percent electricity and 200 gallons of cooling water per refluxed reaction[citation needed] 12, closed vessel can prevent releasing toxic gas and explosions. (wikipedia.org)
  • A bottom valve on a glass vessel typically relates to a lower allowable working pressure. (wikipedia.org)
  • A Fisher-Porter tube or Fisher-Porter vessel is a glass pressure reactor used in the chemical laboratory. (wikipedia.org)
  • Pressure cooking Pressure vessel Biotage Synthesis and Purification Catalog 2008 Nonthermal Microwave Effects Revisited, On the Importance of InternalTemperature Monitoring and Agitation in Microwave Chemistry M. A. Herrero, J. M. Kremsner, C. O. Kappe J. Org. (wikipedia.org)
  • A pressure vessel is a container designed to hold gases or liquids at a pressure substantially different from the ambient pressure. (wikipedia.org)
  • Consequently, pressure vessel design, manufacture, and operation are regulated by engineering authorities backed by legislation. (wikipedia.org)
  • For these reasons, the definition of a pressure vessel varies from country to country. (wikipedia.org)
  • In the United States that code is the ASME Boiler and Pressure Vessel Code (BPVC). (wikipedia.org)
  • Local providences and states in the US began enacting rules for constructing these vessels after some particularly devastating vessel failures occurred killing dozens of people at a time, which made it difficult for manufacturers to keep up with the varied rules from one location to another and the first pressure vessel code was developed starting in 1911 and released in 1914, starting the ASME Boiler and Pressure Vessel Code (BPVC). (wikipedia.org)
  • Pressure piling describes phenomena related to combustion of gases in a tube or long vessel. (wikipedia.org)
  • Where multiple vessels are connected by piping, ignition of gases in one vessel and pressure piling may result in a deflagration to detonation transition and very large explosion pressure. (wikipedia.org)
  • A vacuum pump is used to remove the air out of a vacuum vessel for low-pressure experiments. (wikipedia.org)
  • At observation stations around the world the air pressure reading, regardless of the observation station elevation, is converted to a value that would be observed if that instrument were located at sea level. (weather.gov)
  • Change in pore water pressure: A change in water table elevation, Artesian pressures, deep pumping or flow into tunnels, and desiccation due to surface drying or plant life can bring soil to its preconsolidation pressure. (wikipedia.org)
  • The dynamic pressure, along with the static pressure and the pressure due to elevation, is used in Bernoulli's principle as an energy balance on a closed system. (wikipedia.org)
  • Another study found that the magnitude of increase in intraocular pressure correlates with the intraoral resistance associated with the instrument, and linked intermittent elevation of intraocular pressure from playing high-resistance wind instruments to incidence of visual field loss. (wikipedia.org)
  • The highest adjusted-to-sea level barometric pressure ever recorded (below 750 meters) was at Agata in Evenk Autonomous Okrug, Russia (66°53'N, 93°28'E, elevation: 261 m, 856 ft) on 31 December 1968 of 1083.8 hPa (32.005 inHg). (wikipedia.org)
  • Pressure head is a component of hydraulic head, in which it is combined with elevation head. (wikipedia.org)
  • Pressure develops due to: Water elevation difference, water flowing from higher elevation to lower elevation and causing a velocity head, or with water flow, as exemplified in the Bernoulli's energy equations. (wikipedia.org)
  • Blood pressure ( BP ) is the pressure of circulating blood on the walls of blood vessels . (wikipedia.org)
  • Wikimedia Commons has media related to Pressure vessels . (wikipedia.org)
  • The set out standards and regulations regarding pressure vessels and boilers safety is also very close to the US standards defined by the American Society of Mechanical Engineers (ASME). (wikipedia.org)
  • Pressure equipment - vessels, piping, safety accessories and pressure accessories. (hse.gov.uk)
  • Gauge pressure is the relevant measure of pressure wherever one is interested in the stress on storage vessels and the piping components of fluid flow systems. (tau.ac.il)
  • Root pressure may be important in refilling the xylem vessels. (wikipedia.org)
  • However, in some species vessels refill without root pressure. (wikipedia.org)
  • Glass pressure vessels can also be used in inert applications. (wikipedia.org)
  • Pressure vessels can be dangerous, and fatal accidents have occurred in the history of their development and operation. (wikipedia.org)
  • In most countries, vessels over a certain size and pressure must be built to a formal code. (wikipedia.org)
  • The earliest documented design of pressure vessels is described in the book Codex Madrid I, by Leonardo da Vinci, in 1495, where containers of pressurized air were theorized to lift heavy weights underwater, however vessels resembling what are used today did not come about until the 1800s where steam was generated in boilers helping to spur the industrial revolution. (wikipedia.org)
  • However, with poor material quality and manufacturing techniques along with improper knowledge of design, operation and maintenance there was a large number of damaging and often fatal explosions associated with these boilers and pressure vessels, with a death occurring on a nearly daily basis in the United States. (wikipedia.org)
  • Regardless of the country nearly all recognize the inherent potential hazards of pressure vessels and the need for standards and codes regulating their design and construction. (wikipedia.org)
  • Pressure vessels can theoretically be almost any shape, but shapes made of sections of spheres, cylinders, and cones are usually employed. (wikipedia.org)
  • Because blood proteins cannot escape through capillary endothelium, oncotic pressure of capillary beds tends to draw water into the vessels. (wikipedia.org)
  • Therefore, the air pressure is the same in the space station as the earth's surface (14.7 pounds per square inch). (weather.gov)
  • Pressure gauge , instrument for measuring the condition of a fluid (liquid or gas) that is specified by the force that the fluid would exert, when at rest, on a unit area, such as pounds per square inch or newtons per square centimetre . (britannica.com)
  • The simplest device for measuring static pressures up to about 90 pounds per square inch (62 newtons per square cm) is a U-tube manometer (shown in the figure ), in which one column of a liquid in the tube is open to a region of high pressure and the other column to a region of low pressure . (britannica.com)
  • The Bourdon-tube gauge , invented about 1850, is still one of the most widely used instruments for measuring the pressure of liquids and gases of all kinds, including steam, water, and air up to pressures of 100,000 pounds per square inch (70,000 newtons per square cm). (britannica.com)
  • Other units of pressure, such as pounds per square inch and bar, are also in common use. (wikipedia.org)
  • Ambient pressure may in other circumstances be measured in pounds per square inch (psi) or in standard atmospheres (atm). (wikipedia.org)
  • It is generally expressed in PSI (pounds per square inch) or copper units of pressure. (wikipedia.org)
  • In the United States, atmospheric pressure near sea level is commonly rounded to 15 lbf/in2, and expressed as "15 psi" (15 pounds per square inch. (wikipedia.org)
  • The pressure, expressed in pounds per square inch, pascals, or bar, is designed into the pump but can be varied by adjusting the unloader valve. (wikipedia.org)
  • Ground pressure is measured in pascals (Pa) which corresponds to the United States customary units unit of pounds per square inch (psi). (wikipedia.org)
  • Any externally applied pressure is transmitted to all parts of the enclosed fluid, making possible a large multiplication of force ( hydraulic press principle ). (gsu.edu)
  • Hydraulic operating pressures on offhighway vehicles have increased steadily over the years. (sae.org)
  • pressure dissolution The process that occurs preferentially at the contact surface of grains or crystals as a result of an excess of external pressure relative to the hydraulic pressure of pore fluids. (encyclopedia.com)
  • Electromechanical transducers , which are used in hydraulic controllers, where speed and power are needed, convert changes in pressure of fluid to electrical signals. (britannica.com)
  • During the investigation of an electronic transmission control system for agricultural, off highway and, heavy duty on highway vehicles, it became apparent that a key element in the hydraulic system was the need to accurately regulate oil pressure to the various clutches in the gear train. (sae.org)
  • If we were to divide the dynamic pressure by the product of fluid density and acceleration due to gravity, g, the result is called velocity head, which is used in head equations like the one used for pressure head and hydraulic head. (wikipedia.org)
  • Hydraulic pressure switches have various uses in automobiles, for example, to warn if the engine´s oil pressure falls below a safe level, or to control automatic transmission torque converter lock-up. (wikipedia.org)
  • Blood pressure is influenced by cardiac output , total peripheral resistance and arterial stiffness and varies depending on situation, emotional state, activity, and relative health/disease states. (wikipedia.org)
  • Observational studies demonstrate that people who maintain arterial pressures at the low end of these pressure ranges have much better long-term cardiovascular health. (wikipedia.org)
  • ABPI is known to be unreliable on patients with arterial calcification ( hardening of the arteries ) which results in less or incompressible arteries, as the stiff arteries produce falsely elevated ankle pressure, giving false negatives ). (wikipedia.org)
  • CSF pressure has been shown to be influenced by abrupt changes in intrathoracic pressure during coughing (intraabdominal pressure), valsalva maneuver, and communication with the vasculature (venous and arterial systems). (wikipedia.org)
  • This is often found in patients with diabetes mellitus (41% of patients with peripheral arterial disease (PAD) have diabetes), renal failure or heavy smokers, and toe pressure is a valuable complement to avoid some of these problems. (wikipedia.org)
  • A Doppler ultrasound blood flow detector, commonly called Doppler wand or Doppler probe, and a sphygmomanometer (blood pressure cuff) are usually needed. (wikipedia.org)
  • Because pressure is commonly measured by its ability to displace a column of liquid in a manometer, pressures are often expressed as a depth of a particular fluid (e.g., centimetres of water, millimetres of mercury or inches of mercury). (wikipedia.org)
  • Most commonly fast drops in pressure were achieved by using a quick release valve or a fast burst membrane. (wikipedia.org)
  • citation needed] The SI unit of pressure is the pascal (Pa), which is a very small unit relative to atmospheric pressure on Earth, so kilopascals (kPa) are more commonly used in this context. (wikipedia.org)
  • The Laplace pressure is commonly used to determine the pressure difference in spherical shapes such as bubbles or droplets. (wikipedia.org)
  • An increase in pressure, most commonly due to head injury leading to intracranial hematoma or cerebral edema, can crush brain tissue, shift brain structures, contribute to hydrocephalus, cause brain herniation, and restrict blood supply to the brain. (wikipedia.org)
  • Pressure ulcers most commonly develop in individuals who are not moving about, such as those being bedridden or confined to a wheelchair. (wikipedia.org)
  • Pressure overload may affect any of the four chambers of the heart, though the term is most commonly applied to one of the two ventricles. (wikipedia.org)
  • Differential pressures are commonly used in industrial process systems. (wikipedia.org)
  • It involves making rapid changes to the pressure of an experimental system and observing the return to equilibrium or steady state. (wikipedia.org)
  • By adjusting the top screw, the downward pressure on the diaphragm can be increased, requiring more pressure in the upper chamber to maintain equilibrium. (wikipedia.org)
  • The diaphragm is pushed back by the spring and the valve opens, letting more gas in from the supply until equilibrium is reached between the outlet pressure and the spring. (wikipedia.org)
  • If the supply pressure falls, it is as if the large spring compression is increased allowing more gas and higher pressure to build in the outlet chamber until an equilibrium pressure is reached. (wikipedia.org)
  • Capillary pressure formulas are derived from the pressure relationship between two fluid phases in a capillary tube in equilibrium, which is that force up = force down. (wikipedia.org)
  • Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average or equilibrium) atmospheric pressure, caused by a sound wave. (wikipedia.org)
  • It is possible to work out the equilibrium constant for a chemical reaction involving a mixture of gases given the partial pressure of each gas and the overall reaction formula. (wikipedia.org)
  • The equilibrium vapor pressure is an indication of a liquid's evaporation rate. (wikipedia.org)
  • Tensiometers operate by allowing the pore water to come into equilibrium with a reference pressure indicator through a permeable ceramic cup placed in contact with the soil. (wikipedia.org)
  • Some meteorologists prefer the hectopascal (hPa) for atmospheric air pressure, which is equivalent to the older unit millibar (mbar). (wikipedia.org)
  • Hence, by combining several different types of gauge, it is possible to measure system pressure continuously from 10 mbar down to 10−11 mbar. (wikipedia.org)
  • Standard" pressure, the baseline used universally, is 1013.25 hPa, equivalent to 1013.25 mbar or 29.92 inHg (inches of mercury). (wikipedia.org)
  • Almost any food that can be cooked in steam or water-based liquids can be cooked in a pressure cooker. (wikipedia.org)
  • This type of pressure cooker cannot be opened with a cold water quick-release method and should be operated with caution when releasing vapour through the valve, especially while cooking foamy foods and liquids ( lentils , beans , grains, milk, gravy , etc. (wikipedia.org)
  • Regulators are used for gases and liquids, and can be an integral device with an output pressure setting, a restrictor and a sensor all in the one body, or consist of a separate pressure sensor, controller and flow valve. (wikipedia.org)
  • Gases dissolve, diffuse, and react according to their partial pressures, and not according to their concentrations in gas mixtures or liquids. (wikipedia.org)
  • As can be seen in the chart, the liquids with the highest vapor pressures have the lowest normal boiling points. (wikipedia.org)
  • Note that at higher altitudes, the atmospheric pressure is less than that at sea level, so boiling points of liquids are reduced. (wikipedia.org)
  • And does this building pressure change the way water flows? (amnh.org)
  • The pressure drop as fluid flows from a container can be modeled by Poiseuille's law . (gsu.edu)
  • It is primarily this ram pressure (rather than friction) that heats the air that in turn heats the meteoroid as it flows around it. (wikipedia.org)
  • Many authors define dynamic pressure only for incompressible flows. (wikipedia.org)
  • For compressible flows, these authors use the concept of impact pressure. (wikipedia.org)
  • However, the definition of dynamic pressure can be extended to include compressible flows. (wikipedia.org)
  • The concepts of total pressure and dynamic pressure arise from Bernoulli's equation and are significant in the study of all fluid flows. (wikipedia.org)
  • citation needed] Some authors in the field of compressible flows use the term dynamic pressure or compressible dynamic pressure instead of impact pressure. (wikipedia.org)
  • Pressure drop occurs when frictional forces, caused by the resistance to flow, act on a fluid as it flows through the tube. (wikipedia.org)
  • During human ventilation, air flows because of pressure gradients. (wikipedia.org)
  • Like a float carburetor, a pressure carburetor has a barrel with a venturi inside it through which air flows on its way to the engine cylinders. (wikipedia.org)
  • The fuel mixture is automatically altitude-controlled by bleeding higher pressure air from chamber A to the chamber B as it flows though a tapered needle valve. (wikipedia.org)
  • Root pressure occurs in the xylem of some vascular plants when the soil moisture level is high either at night or when transpiration is low during the day. (wikipedia.org)
  • Grazing pressure that occurs naturally within an environment is higher than grazing pressure from livestock animals. (wikipedia.org)
  • Pressure urticaria (also known as delayed pressure urticaria) is a physical urticaria caused by pressure applied to the skin, and is characterized by the development of swelling and pain that usually occurs 3 to 12 hours after local pressure has been applied. (wikipedia.org)
  • Cuff pressure is then slowly lowered until flow can be detected in the distal part of the toe, e.g. by optical means (photocell), by expansion of the toe as measured with strain gauge plethysmography, or by visual assessment of color change by an experienced examiner, and the pressure at which this occurs is recorded. (wikipedia.org)
  • High-pressure experimentation has led to the discovery of the types of minerals which are believed to exist in the deep mantle of the Earth, such as silicate perovskite, which is thought to make up half of the Earth's bulk, and post-perovskite, which occurs at the core-mantle boundary and explains many anomalies inferred for that region. (wikipedia.org)
  • Pressure alopecia (also known as "Postoperative alopecia," and "Pressure-induced alopecia") occurs in adults after prolonged pressure on the scalp during general anesthesia, with the head fixed in one position, and may also occur in chronically ill persons after prolonged bed rest in one position that causes persistent pressure on one part of the scalp, all likely due to pressure-induced ischemia. (wikipedia.org)
  • Likewise, it should be noted that the part of the barrel that is subject to the highest pressures is the throat, or the point closest to the chamber at which the bullet engages the rifling. (wikipedia.org)
  • citation needed] Pressure "landmarks": typical pressures reached by large-volume presses are up to 30-40 GPa, pressures that can be generated inside diamond anvil cells are ~1000 GPa, pressure in the center of the Earth is 364 GPa, and highest pressures ever achieved in shock waves are over 100,000 GPa. (wikipedia.org)
  • The differential pressure is indicated by the difference in level between the two columns of liquid, and it is calculated as the difference in level multiplied by the density of the liquid. (britannica.com)
  • In a venturi flow meter, the differential pressure head can be used to calculate the differential velocity head, which are equivalent in the adjacent picture. (wikipedia.org)
  • Differential pressure is the difference in pressure between two points. (wikipedia.org)
  • Differential pressure gauges have two inlet ports, each connected to one of the volumes whose pressure is to be monitored. (wikipedia.org)
  • A pressure switch will have a differential range around its setpoint in which small changes of pressure do not change the state of the contacts. (wikipedia.org)
  • A differential pressure switch may be installed across a filter element to sense increased pressure drop, indicating the need for filter cleaning or replacement. (wikipedia.org)
  • Change in soil structure due to aging (secondary compression): Over time, soil will consolidate even after high pressures from loading and pore water pressure have been depleted. (wikipedia.org)
  • Pore water pressure (sometimes abbreviated to pwp) refers to the pressure of groundwater held within a soil or rock, in gaps between particles (pores). (wikipedia.org)
  • Pore water pressure is vital in calculating the stress state in the ground soil mechanics, from Terzaghi's expression for the effective stress of a soil. (wikipedia.org)
  • This parameter is called the effective stress of the soil, basically equal to the difference in a soil's total stress and pore water pressure. (wikipedia.org)
  • The pore water pressure is essential in differentiating a soil's total stress from its effective stress. (wikipedia.org)
  • For other uses, see Peer pressure (disambiguation) . (wikipedia.org)
  • Peer pressure (or social pressure ) is the direct influence on people by peers , or the effect on an individual who gets encouraged to follow their peers by changing their attitudes , values or behaviors to conform to those of the influencing group or individual. (wikipedia.org)
  • However, a person does not need to be a member or be seeking membership of a group to be affected by peer pressure.peer pressure can decrease one's confidence .It can affect the lives of the students drastically. (wikipedia.org)
  • Peer pressure can affect individuals of all ethnicities, genders and ages, however. (wikipedia.org)
  • Peer pressure has moved from strictly face-to-face interaction to digital interaction as well. (wikipedia.org)
  • She'd just had a big dose of peer pressure. (kidshealth.org)
  • But you probably hear adults - parents, teachers, guidance counselors, etc. - talk about peer pressure more than the benefits of belonging to a peer group. (kidshealth.org)
  • However, a person does not need to be a member or be seeking membership of a group to be affected by peer pressure. (wikipedia.org)
  • Adolescence is the time when a person is most susceptible to peer pressure because peers become an important influence on behavior during adolescence, and peer pressure has been called a hallmark of adolescent experience. (wikipedia.org)
  • Its companion series, Pressure 2, was actually heavily edited reruns of the 1997-98 game show Peer Pressure. (wikipedia.org)
  • Piping - piping components intended for the transport of fluids when connected together for integration into a pressure system. (hse.gov.uk)
  • Regardless of the system, a pressure difference arises at the resulting curved interface between the two fluids. (wikipedia.org)
  • If we have two different kind of fluids in our volume then the slope of our pressure prism will not be constant over the depth and rather be somewhat like shown in figure 3. (wikipedia.org)
  • The concept of pressure is central to the study of fluids. (wikipedia.org)
  • Pressure switches are widely used in industry to automatically supervise and control systems that use pressurized fluids. (wikipedia.org)
  • The pressure coefficient is a parameter for studying the flow of incompressible fluids such as water, and also the low-speed flow of compressible fluids such as air. (wikipedia.org)
  • This relationship is valid for the flow of incompressible fluids where variations in speed and pressure are sufficiently small that variations in fluid density can be neglected. (wikipedia.org)
  • Pressure varies smoothly from the Earth's surface to the top of the mesosphere . (wikipedia.org)
  • I read in New Scientist that the pressure at Earth's core is 3.6 million atmospheres. (newscientist.com)
  • But since g varies little over depths which are a very small fraction of the Earth's radius, it is placed outside the integral in practice for most near-surface applications which require an assessment of lithostatic pressure. (wikipedia.org)
  • In atmospheric science, surface pressure is the atmospheric pressure at a location on Earth's surface. (wikipedia.org)
  • Within planetary atmospheres (including the Earth's), the pressure gradient is a vector pointing roughly downwards, because the pressure changes most rapidly vertically, increasing downwards, see vertical pressure variation. (wikipedia.org)
  • Since localized areas of warm air are less dense than their surroundings, this warmer air rises, which lowers atmospheric pressure near that portion of the Earth's surface. (wikipedia.org)
  • The highest adjusted-to-sea level barometric pressure ever recorded on Earth (above 750 meters) was 1085.7 hPa (32.06 inHg) measured in Tosontsengel, Mongolia on 19 December 2001. (wikipedia.org)
  • The lowest recorded non-tornadic barometric pressure was 870 hectopascals (26 inHg), occurred in the Western Pacific during Typhoon Tip on 12 October 1979. (wikipedia.org)
  • These instruments employ mechanical linkages and so are primarily useful for measuring static pressures or pressures that change slowly. (britannica.com)
  • Depending on cooking control capability, there are three generations of electric pressure cookers: First-generation, with mechanical timer. (wikipedia.org)
  • Pressure control (PC) is a mode of mechanical ventilation alone and a variable within other modes of mechanical ventilation. (wikipedia.org)
  • Plateau pressure (PPLAT) is the pressure applied to small airways and alveoli during positive-pressure mechanical ventilation. (wikipedia.org)
  • Mechanical Pressure Switch with integrated connector Mechanical Pressure Switch with Plug-in connector Electrical pressure switch with LED display A pressure sensitive mat provides a contact signal when force is applied anywhere within the area of the mat. (wikipedia.org)
  • In fluid dynamics, many authors use the term static pressure in preference to just pressure to avoid ambiguity. (wikipedia.org)
  • The pressure gradient is defined only at those spatial scales at which pressure (more generally fluid dynamics) itself is defined. (wikipedia.org)
  • The pressure coefficient is a dimensionless number which describes the relative pressures throughout a flow field in fluid dynamics. (wikipedia.org)
  • This experiment, which can be completed in a single class period, examines how pressure affects water flow. (amnh.org)
  • In small groups, students work with water and a soda bottle, and then relate their findings to pressure in the deep ocean. (amnh.org)
  • A series of inquiry-based questions to get students thinking about pressure, both in the air and under water. (amnh.org)
  • If valves A and B are open but C and D closed, then the steam pressure can pump water to height h2. (gsu.edu)
  • If cooling water is supplied to the cylinder, then the steam will condense, precipitously dropping its vapor pressure . (gsu.edu)
  • If a few cubic centimeters of water is poured into such a can (just enough to cover the bottom) and the can is held above a laboratory burner for about 30 seconds, the water can be brought to the boiling point where its vapor pressure is equal to atmospheric pressure. (gsu.edu)
  • If the can is quickly inverted into a beaker of water, sealing off the opening, the sudden drop in vapor pressure will result in enough net inward pressure to quickly crush the can. (gsu.edu)
  • If one is at the bottom of a deep pool of water, the water pressure will cause pain in one's ears. (tau.ac.il)
  • In air, sound pressure can be measured using a microphone, and in water with a hydrophone. (wikipedia.org)
  • Root pressure is caused by this accumulation of water in the xylem pushing on the rigid cells. (wikipedia.org)
  • Root pressure provides a force, which pushes water up the stem, but it is not enough to account for the movement of water to leaves at the top of the tallest trees. (wikipedia.org)
  • The maximum root pressure measured in some plants can raise water only to 6.87 meters, and the tallest trees are over 100 meters tall. (wikipedia.org)
  • Root pressure can transport water and dissolved mineral nutrients from roots through the xylem to the tops of relatively short plants when transpiration is low or zero. (wikipedia.org)
  • It is reduction in the diffusion pressure of water in solution or cell over its pure state due to presence of solutes in it and forces opposing diffusion. (wikipedia.org)
  • Diffusion pressure of water is maximum and its theoretical value is 1236 atm. (wikipedia.org)
  • The difference between diffusion pressure of pure water and solution is called diffusion pressure deficit (DPD). (wikipedia.org)
  • When a plant cell is placed in hypotonic solution, water enters into a cell by osmosis and as a result turger pressure develops. (wikipedia.org)
  • For example, if the original fluid was water and we replaced it with mercury at the same pressure, we would expect to see a rather different value for pressure head. (wikipedia.org)
  • This process will stop once the pressures of the water and sugar water on both sides of the membrane become equal. (wikipedia.org)
  • Use of high pressure water jet for cleaning hard surfaces Pressure washing or power washing is the use of high-pressure water spray to remove loose paint, mold, grime, dust, mud, chewing gum and dirt from surfaces and objects such as buildings, vehicles and concrete surfaces. (wikipedia.org)
  • Steel Structures Painting Council (1995), Surface Preparation and Cleaning of Steel and Other Hard Materials by High- and Ultrahigh-Pressure Water Jetting Prior to Recoating. (wikipedia.org)
  • Energy is consumed by the circulation pump, however, because this pump merely circulates and does not pressurize water, its energy consumption is almost negligible: less than 3% of the energy consumed by the high pressure pump. (wikipedia.org)
  • Many early SWRO plants built in the 1970s and early 1980s had an energy consumption of over 6.0 kWh per cubic meter of potable water produced, due to low membrane performance, pressure drop limitations and the absence of energy recovery devices. (wikipedia.org)
  • An example where a pressure exchange engine finds application is in the production of potable water using the reverse osmosis membrane process. (wikipedia.org)
  • The input saline solution is then divided by the membrane array into super saline solution (brine) at high pressure and potable water at low pressure. (wikipedia.org)
  • In Ecballium elaterium, or squirting cucumber, turgor pressure builds up in the fruit to the point that aggressively detaches from the stalk, and seeds and water are squirted everywhere as the fruit falls to the ground. (wikipedia.org)
  • Uses of pneumatic pressure switches include: Switch a household well water pump automatically when water is drawn from the pressure tank. (wikipedia.org)
  • Consequently, an engineering model can be tested in a wind tunnel or water tunnel, pressure coefficients can be determined at critical locations around the model, and these pressure coefficients can be used with confidence to predict the fluid pressure at those critical locations around a full-size aircraft or boat. (wikipedia.org)
  • Low-pressure areas can also form due to organized thunderstorm activity over warm water. (wikipedia.org)
  • Pore water pressures below the phreatic level of the groundwater are measured with piezometers. (wikipedia.org)
  • Pore water pressures under unsaturated conditions (vadose zone) are measured in with tensiometers. (wikipedia.org)
  • Adsorption pressure, attraction of surrounding soil particles to one another by adsorbed water films. (wikipedia.org)
  • The United States Bureau of Reclamation has a standard for monitoring water pressure in a rock mass with piezometers. (wikipedia.org)