query: where is the hydrostatic pressure of the blood created

pos: Hydrostatics In medicine, hydrostatic pressure in blood vessels is the pressure of the blood against the wall. It is the opposing force to oncotic pressure. Statistical mechanics shows that, for a gas of constant temperature, "T", its pressure, "p" will vary with height, "h", as: where: This is known as the barometric formula, and may be derived from assuming the pressure is hydrostatic. If there are multiple types of molecules in the gas, the partial pressure of each type will be given by this equation. Under most conditions, the distribution of each species of gas is independent of the other species.

pos: Hydrostatics In medicine, hydrostatic pressure in blood vessels is the pressure of the blood against the wall. It is the opposing force to oncotic pressure. Statistical mechanics shows that, for a gas of constant temperature, "T", its pressure, "p" will vary with height, "h", as: where: This is known as the barometric formula, and may be derived from assuming the pressure is hydrostatic. If there are multiple types of molecules in the gas, the partial pressure of each type will be given by this equation. Under most conditions, the distribution of each species of gas is independent of the other species.

neg: Microcirculation called filtration. This kind of movement is favored by blood hydrostatic pressure (BHP) and interstitial fluid osmotic pressure (IFOP). Otherwise, if the substances move from the interstitial fluid to the blood in capillaries, the process is called reabsorption. The pressures that favor this movement are blood colloid osmotic pressure (BCOP) and interstitial fluid hydrostatic pressure (IFHP). A substance will be filtrated or reabsorbed depending on the net filtration pressure (NFP). This force is the result of the balance between hydrostatic (BHP and IFHP) and osmotic pressures (IFOP and BCOP). These pressures are known as the Starling forces. If the calculation

neg: Underwater diving done underwater. Immersion of the human body in water affects the circulation, renal system, fluid balance, and breathing, because the external hydrostatic pressure of the water provides support against the internal hydrostatic pressure of the blood. This causes a blood shift from the extravascular tissues of the limbs into the chest cavity, and fluid losses known as immersion diuresis compensate for the blood shift in hydrated subjects soon after immersion. Hydrostatic pressure on the body from head-out immersion causes negative pressure breathing which contributes to the blood shift. The blood shift causes an increased respiratory and cardiac workload. Stroke volume

neg: Hemodynamics value, the mean arterial pressure (MAP), which is calculated as follows: where: Differences in mean blood pressure are responsible for blood flow from one location to another in the circulation. The rate of mean blood flow depends on both blood pressure and the resistance to flow presented by the blood vessels. Mean blood pressure decreases as the circulating blood moves away from the heart through arteries and capillaries due to viscous losses of energy. Mean blood pressure drops over the whole circulation, although most of the fall occurs along the small arteries and arterioles. Gravity affects blood pressure via hydrostatic

neg: Physiology of underwater diving the ability to function effectively at depth. Immersion of the human body in water has effects on the circulation, renal system and fluid balance, and breathing, which are caused by the external hydrostatic pressure of the water providing support against the internal hydrostatic pressure of the blood. This causes a blood shift from the extravascular tissues of the limbs into the chest cavity, and fluid losses known as immersion diuresis compensate for the blood shift in hydrated subjects soon after immersion. Hydrostatic pressure on the body due to head out immersion causes negative pressure breathing which contributes to the blood

neg: Kwashiorkor by re-absorption of water and proteins which are then returned to the blood. Compromised fluid recovery results in the characteristic belly distension observed in highly malnourished children. Capillary exchange between the lymphatic system and the bloodstream is stunted due to the inability of the body to effectively overcome the hydrostatic pressure gradient. Proteins, mainly albumin, are responsible for creating the colloid osmotic pressure (COP) observed in the blood and tissue fluids. The difference in the COP of the blood and tissue is called the oncotic pressure. The oncotic pressure is in direct opposition with the hydrostatic pressure and tends to

neg: Hemodialysis Hemodialysis utilizes counter current flow, where the dialysate is flowing in the opposite direction to blood flow in the extracorporeal circuit. Counter-current flow maintains the concentration gradient across the membrane at a maximum and increases the efficiency of the dialysis. Fluid removal (ultrafiltration) is achieved by altering the hydrostatic pressure of the dialysate compartment, causing free water and some dissolved solutes to move across the membrane along a created pressure gradient. The dialysis solution that is used may be a sterilized solution of mineral ions. Urea and other waste products, potassium, and phosphate diffuse into the dialysis solution. However, concentrations

neg: Chlortalidone renal medullary collecting duct. This reduced delivery of solute to the collecting tubule and medullary collecting duct allows increased water resorption and higher concentration of urine, which leads to reversal of nephrogenic diabetes insipidus by a means that is independent of vasopressin. Chlortalidone may improve edema by increasing urinary salt and water excretion, lowering intravascular hydrostatic pressure and thereby lowering transcapillary pressure. See Starling Equation. Edema may be caused by either increased hydrostatic pressure or reduced oncotic pressure in the blood vessels. Edema due to increased hydrostatic pressure may be a result of serious cardiopulmonary disease (which reduces glomerular perfusion

neg: Hydrostatic seal Hydrostatic seal A Hydrostatic Seal is a non-contacting mechanical seal that operates under an equilibrium of forces. Unlike traditional hydrodynamic seals, Hydrostatic seals have two different pressure zones that are used to establish a balanced pressure zone between two seal faces. The two pressure system makes the seal unique because typical mechanical seals have one pressure zone that created causes a buildup of pressure that will eventually cause the seal to malfunction. After pressure has come to an equilibrium at the seal face, an incompressible fluid is then released between the two seal faces. The fluid creates a film around

neg: Macula densa rate), resulting in a decreased concentration of sodium and chloride ions in the filtrate and/or decreased filtrate flow rate. Reduced blood pressure means decreased venous pressure and, hence, a decreased peritubular capillary pressure. This results in a smaller capillary hydrostatic pressure, which causes an increased absorption of sodium ions into the vasa recta at the proximal tubule. Hence, a decrease in blood pressure results in less sodium chloride present at the distal tubule, where the macula densa is located. The macula densa senses this drop in salt concentration and responds through two mechanisms: First, it triggers dilation of the renal

neg: Foam hydrostatic pressure in the liquid is designated by formula_12. The change in pressure across the interface from gas to liquid is equal to the capillary pressure; hence, where R and R are the radii of curvature and are set as positive. At the stem of the bubble, R and R are the radii of curvature also treated as positive. Here the hydrostatic pressure in the liquid has to take in account z, the distance from the top to the stem of the bubble. The new hydrostatic pressure at the stem of the bubble is "p"("ρ" − "ρ")"z". The hydrostatic pressure

neg: Blood pressure occurs along the small arteries and arterioles. Gravity affects blood pressure via hydrostatic forces (e.g., during standing), and valves in veins, breathing, and pumping from contraction of skeletal muscles also influence blood pressure in veins. Most influences on blood pressure can be understood in terms of their effect on cardiac output and resistance (the determinants of mean arterial pressure). Some factors are: In practice, each individual's autonomic nervous system and other systems regulating blood pressure respond to and regulate all these factors so that, although the above issues are important, they rarely act in isolation and the actual arterial pressure

neg: Physiology of dinosaurs the top of the head, because this column of blood must have a pressure at the bottom equal to the hydrostatic pressure derived from the density of blood and gravity. Added to this pressure is that required to move the blood through the circulatory system. It was pointed out in 1976 that, because of their height, many dinosaurs had minimum blood pressures within the endothermic range, and that they must have had four-chambered hearts to separate the high pressure circuit to the body from the low pressure circuit to the lungs. It was not clear whether these dinosaurs had high

neg: Angiotensin renal blood flow depending on the setting. Increases in systemic blood pressure will maintain renal perfusion pressure; however, constriction of the afferent and efferent glomerular arterioles will tend to restrict renal blood flow. The effect on the efferent arteriolar resistance is, however, markedly greater, in part due to its smaller basal diameter; this tends to increase glomerular capillary hydrostatic pressure and maintain glomerular filtration rate. A number of other mechanisms can affect renal blood flow and GFR. High concentrations of Angiotensin II can constrict the glomerular mesangium, reducing the area for glomerular filtration. Angiotensin II is a sensitizer to tubuloglomerular

neg: Atmospheric model filter out vertically moving acoustic waves from the vertical momentum equation, which significantly increases the time step used within the model's run. This is known as the hydrostatic approximation. Hydrostatic models use either pressure or sigma-pressure vertical coordinates. Pressure coordinates intersect topography while sigma coordinates follow the contour of the land. Its hydrostatic assumption is reasonable as long as horizontal grid resolution is not small, which is a scale where the hydrostatic assumption fails. Models which use the entire vertical momentum equation are known as nonhydrostatic. A nonhydrostatic model can be solved anelastically, meaning it solves the complete continuity equation

neg: Macula densa afferent arteriole, decreasing afferent arteriole resistance and, thus, offsetting the decrease in glomerular hydrostatic pressure caused by the drop in blood pressure. Second, macula densa cells release prostaglandins, which triggers granular juxtaglomerular cells lining the afferent arterioles to release renin into the bloodstream. (The juxtaglomerular cells can also release renin independently of the macula densa. They are also triggered by baroreceptors lining the arterioles, and release renin if a fall in blood pressure in the arterioles is detected. Furthermore, activation of the sympathetic nervous system stimulates renin release through activation of beta-1 receptors.) Thus, a drop in blood pressure results

neg: Ultrafiltration (renal) the filter, from the blood in the glomerular capsule across the basement membrane of the Bowman's capsule and into the renal tubules. This process is called ultrafiltration; the resulting fluid, virtually free of large proteins and blood cells, is referred to as glomerular filtrate, or ultrafiltrate. Further modification of ultrafiltrate, by reabsorption and secretion, transforms it into urine. Glomerular pressure is about 75 millimeters of mercury (10 kPa). It is opposed by osmotic pressure (30 mmHg, 4.0 kPa) and hydrostatic pressure (20 mmHg, 2.7 kPa) of solutes present in capsular space. This difference in pressure is called effective pressure (25

neg: Diving reflex due to head out immersion in water causes negative pressure breathing which shifts blood into the intrathoracic circulation. Lung volume decreases in the upright position due to cranial displacement of the abdomen due to hydrostatic pressure, and resistance to air flow in the airways increases significantly because of the decrease in lung volume. Hydrostatic pressure differences between the interior of the lung and the breathing gas delivery, increased breathing gas density due to ambient pressure, and increased flow resistance due to higher breathing rates may all cause increased work of breathing and fatigue of the respiratory muscles. There appears to

neg: Efferent arteriole to increased levels of angiotensin II. Pressure in glomerular capillaries is therefore maintained and glomerular filtration rate remains adequate. However, in states of where angiotensin II is very high for a prolonged period of time, the colloid oncotic pressure of the capillaries will increase, counteracting the increased hydrostatic pressure from the efferent constriction. This will decrease the glomerular filtration rate, depending on the level of oncotic increase in the capillaries, resulting in a decreased filtration fraction. Efferent arteriole The efferent arterioles are blood vessels that are part of the urinary tract of organisms. Efferent (from Latin ex + ferre) means

neg: Kidney the kidney is the nephron. It processes the blood supplied to it via filtration, reabsorption, secretion and excretion; the consequence of those processes is the production of urine. Filtration, which takes place at the renal corpuscle, is the process by which cells and large proteins are retained while materials of smaller molecular weights are filtered from the blood to make an ultrafiltrate that eventually becomes urine. The kidney generates 180 liters of filtrate a day. The process is also known as hydrostatic filtration due to the hydrostatic pressure exerted on the capillary walls. Reabsorption is the transport of molecules from

neg: Hemofiltration a semi-permeable membrane. However, solute movement with hemofiltration is governed by convection rather than by diffusion. With hemofiltration, dialysate is not used. Instead, a positive hydrostatic pressure drives water and solutes across the filter membrane from the blood compartment to the filtrate compartment, from which it is drained. Solutes, both small and large, get dragged through the membrane at a similar rate by the flow of water that has been engendered by the hydrostatic pressure. Thus convection overcomes the reduced removal rate of larger solutes (due to their slow speed of diffusion) seen in hemodialysis. Hemofiltration is sometimes used in

neg: Foam in a liquid (phase 2) and point A designates the top of the bubble while point B designates the bottom of the bubble. At the top of the bubble at point A, the pressure in the liquid is assumed to be p as well as in the gas. At the bottom of the bubble at point B, the hydrostatic pressure is: where ρ and ρ is the density for a gas and liquid respectively. The difference in hydrostatic pressure at the top of the bubble is 0, while the difference in hydrostatic pressure at the bottom of the bubble across

neg: Decompression (diving) using an atmospheric diving suit do not need to decompress as they are never exposed to high ambient pressure. When a diver descends in the water the hydrostatic pressure, and therefore the ambient pressure, rises. Because breathing gas is supplied at ambient pressure, some of this gas dissolves into the diver's blood and is transferred by the blood to other tissues. Inert gas such as nitrogen or helium continues to be taken up until the gas dissolved in the diver is in a state of equilibrium with the breathing gas in the diver's lungs, at which point the diver is

neg: Diffusiophoresis and diffusioosmosis and so in interface formula_38, and so there formula_39. Assuming continuity of the solvent contribution into the interface we have a gradient of the hydrostatic pressure in the interface formula_40 i.e., in the interface there is a gradient of the hydrostatic pressure equal to the negative of the bulk gradient in the osmotic pressure. It is this gradient in the interface in the hydrostatic pressure formula_21 that creates the diffusioosmotic flow. Now that we have formula_42, we can substitute into the Stokes equation, and integrate twice, then formula_43 formula_44 where formula_45, formula_46, formula_47 and formula_48 are integration constants. Far from

neg: Diuresis within the body to conserve heat. The body detects an increase in the blood pressure and inhibits the release of vasopressin (also known as antidiuretic hormone (ADH)), causing an increase in the production of urine. The "pressure" component is caused by the hydrostatic pressure of the water directly increasing blood pressure. Its significance is indicated by the fact that the temperature of the water does not substantially affect the rate of diuresis. Partial immersion of only the limbs does not cause increased urination. Thus, the hand in warm water trick (immersing the hand of a sleeping person in water to

neg: Obesity hypoventilation syndrome ventilatory response in a vicious circle. Low oxygen levels lead to hypoxic pulmonary vasoconstriction, the tightening of small blood vessels in the lung to create an optimal distribution of blood through the lung. Persistently low oxygen levels causing chronic vasoconstriction leads to increased pressure on the pulmonary artery (pulmonary hypertension), which in turn puts strain on the right ventricle, the part of the heart that pumps blood to the lungs. The right ventricle undergoes remodeling, becomes distended and is less able to remove blood from the veins. When this is the case, raised hydrostatic pressure leads to accumulation of fluid

neg: Hydrostatic stress (or thickness) of each given layer of material. For example, the magnitude of the hydrostatic stress felt at a point under ten meters of fresh water would be where the index formula_8 indicates "water". Because the hydrostatic stress is isotropic, it acts equally in all directions. In tensor form, the hydrostatic stress is equal to where formula_10 is the 3-by-3 identity matrix. Hydrostatic stress In continuum mechanics, a hydrostatic stress is an isotropic stress that is given by the weight of water above a certain point. It is often used interchangeably with "pressure" and is also known as confining stress,

neg: Hydrostatic shock (firearms) hypothesized, "alterations in brain function following blast exposure are induced by kinetic energy transfer of blast overpressure via great blood vessels in abdomen and thorax to the central nervous system." This hypothesis is supported by observations of neural effects in the brain from localized blast exposure focused on the lungs in experiments in animals. "Hydrostatic shock" expresses the idea that organs can be damaged by the pressure wave in addition to damage from direct contact with the penetrating projectile. If one interprets the "shock" in the term "hydrostatic shock" to refer to the physiological effects rather than the physical wave

neg: Well control kick, bottomhole pressure is equal to the hydrostatic pressure in the annulus plus the casing (wellhead or surface pressure) pressure. During circulation, the bottomhole pressure is equal to the hydrostatic pressure on the annular side plus the annular pressure loss (APL). During circulating with a rotating head the bottomhole pressure is equal to the hydrostatic pressure on the annular side, plus the annular pressure loss, plus the rotating head backpressure. Bottomhole pressure is equal to hydrostatic pressure on the annular side, plus annular pressure loss, plus choke (casing) pressure. For subsea, add choke line pressure loss. An accurate evaluation of

neg: Blood plasma Starling forces across capillary walls. For example, when blood pressure drops in circulatory shock, Starling forces drive fluid into the interstitium, causing third spacing. Standing still for a prolonged period will cause an increase in transcapillary hydrostatic pressure. As a result, approximately 12% of blood plasma volume will cross into the extravascular compartment. This causes an increase in hematocrit, serum total protein, blood viscosity and, as a result of increased concentration of coagulation factors, it causes orthostatic hypercoagulability. The use of blood plasma as a substitute for whole blood and for transfusion purposes was proposed in March 1918, in the

neg: Edema Generation of interstitial fluid is regulated by the forces of the Starling equation. Hydrostatic pressure within blood vessels tends to cause water to filter out into the tissue. This leads to a difference in protein concentration between blood plasma and tissue. As a result, the colloidal or oncotic pressure of the higher level of protein in the plasma tends to draw water back into the blood vessels from the tissue. Starling's equation states that the rate of leakage of fluid is determined by the difference between the two forces and also by the permeability of the vessel wall to water,

neg: Ultrafiltration (renal) Ultrafiltration (renal) In renal physiology, ultrafiltration occurs at the barrier between the blood and the filtrate in the glomerular capsule (Bowman's capsule) in the kidneys. As in nonbiological examples of ultrafiltration, pressure (in this case blood pressure) and concentration gradients lead to a separation through a semipermeable membrane (provided by the podocytes). The Bowman's capsule contains a dense capillary network called the glomerulus. Blood flows into these capillaries through the afferent arterioles and leaves through the efferent arterioles. The high hydrostatic pressure forces small molecules in the tubular fluid such as water, glucose, amino acids, sodium chloride and urea through

neg: Peritubular capillaries sent towards the bladder and out of the body. Basically, they reabsorb useful substances such as glucose and amino acids and secrete certain mineral ions and excess water into the tubule. The majority of exchange through the peritubular capillaries occurs because of chemical gradients osmosis and hydrostatic pressure. Movement of water into the peritubular capillaries is due to the loss of water from the glomerulus during filtration, which increases the colloid osmotic pressure of the blood. This blood leaves the glomerulus via the efferent arteriole, which supplies the peritubular capillaries. The higher osmolarity of the blood in the peritubular capillaries

neg: Fluid compartments moment. All of the aforementioned fluids are produced by active cellular processes working with blood plasma as the raw material, and they are all more or less similar to blood plasma except for certain modifications tailored to their function. For example, the cerebrospinal fluid is made by various cells of the CNS, mostly the ependymal cells, from blood plasma. "Fluid shifts" occur when the body's fluids move between the fluid compartments. Physiologically, this occurs by a combination of hydrostatic pressure gradients and osmotic pressure gradients. Water will move from one space into the next passively across a semi permeable membrane

neg: Fluid compartments until the hydrostatic and osmotic pressure gradients balance each other. Many medical conditions can cause fluid shifts. When fluid moves out of the intravascular compartment (the blood vessels), blood pressure can drop to dangerously low levels, endangering critical organs such as the brain, heart and kidneys; when it shifts out of the cells (the intracellular compartment), cellular processes slow down or cease from intracellular dehydration; when excessive fluid accumulates in the interstitial space, oedema develops; and fluid shifts into the brain cells can cause increased cranial pressure. Fluid shifts may be compensated by fluid replacement or diuretics. "Third spacing" is

neg: Well control actual surge and swab pressures can be accomplished with the use of WORKPRO and DRILPRO calculator programs or hydraulics manuals. In well control, it is defined as the difference between the formation pressure and the bottomhole hydrostatic pressure. These are classified as overbalanced, underbalanced and balanced. It means the hydrostatic pressure exerted on the bottom of the hole is greater than the formation pressure. i.e. HP > FP It means the hydrostatic pressure exerted on the bottom of the hole is less than the formation pressure. i.e. HP < FP It means the hydrostatic pressure exerted on the bottom of

neg: Hydrostatic test is usually tested by measuring permanent deformation of the container. Hydrostatic testing is the most common method employed for testing pipes and pressure vessels. Using this test helps maintain safety standards and durability of a vessel over time. Newly manufactured pieces are initially qualified using the hydrostatic test. They are then re-qualified at regular intervals using the "proof pressure test" which is also called the "modified hydrostatic test". Testing of pressure vessels for transport and storage of gases is very important because such containers can explode if they fail under pressure. Hydrostatic tests are conducted under the constraints of either

neg: Physiology of underwater diving shift. The blood shift causes an increased respiratory and cardiac workload. Stroke volume is not greatly affected by immersion or variation in ambient pressure but slowed heartbeat reduces the overall cardiac output, particularly due to the diving reflex in breath-hold diving. Lung volume decreases in the upright position due to cranial displacement of the abdomen due to hydrostatic pressure, and resistance to air flow in the airways increases significantly because of the decrease in lung volume. There appears to be a connection between pulmonary edema and increased pulmonary blood flow and pressure which results in capillary engorgement. This may occur

neg: Hydrostatic equilibrium afforded the definition could affect the classification of the asteroid Vesta, which may have solidified while in hydrostatic equilibrium but was subsequently significantly deformed by large impacts (now 572.6 × 557.2 × 446.4 km). In the atmosphere, the pressure of the air decreases with increasing altitude. This pressure difference causes an upward force called the pressure-gradient force. The force of gravity balances this out, keeping the atmosphere bound to Earth and maintaining pressure differences with altitude. Hydrostatic equilibrium In fluid mechanics, a fluid is said to be in hydrostatic equilibrium or hydrostatic balance when it is at rest, or when

neg: Fluid compartments (the blood plasma). The other intravascular fluid is lymph. It too represents both the intracellular compartment (the fluid inside its lymphocytes) and the extracellular compartment (the noncellular matrix of the lymph, which is roughly equivalent to serum). The average volume of plasma in the average (70 kg) male is approximately 3.5 liters. The volume of the intravascular compartment is regulated in part by hydrostatic pressure gradients, and by reabsorption by the kidneys. The third extracellular compartment, the transcellular, consists of those spaces in the body where fluid does not normally collect in larger amounts, or where any significant fluid collection

neg: Rayleigh–Taylor instability instability forming. The RT instability can be seen as the result of baroclinic torque created by the misalignment of the pressure and density gradients at the perturbed interface, as described by the two-dimensional inviscid vorticity equation, formula_79, where ω is vorticity, ρ density and "p" is the pressure. In this case the dominant pressure gradient is hydrostatic, resulting from the acceleration. When in the unstable configuration, for a particular harmonic component of the initial perturbation, the torque on the interface creates vorticity that will tend to increase the misalignment of the gradient vectors. This in turn creates additional vorticity, leading

neg: Mitral valve stenosis cm, there will be an increase in the left atrial pressures (required to push blood through the stenotic valve). Since the normal left ventricular diastolic pressures is about 5 mmHg, a pressure gradient across the mitral valve of 20 mmHg due to severe mitral stenosis will cause a left atrial pressure of about 25 mmHg. This left atrial pressure is transmitted to the pulmonary vasculature and causes pulmonary hypertension. Pulmonary capillary pressures in this level cause an imbalance between the hydrostatic pressure and the oncotic pressure, leading to extravasation of fluid from the vascular tree and pooling of fluid in

neg: Hydrostatics force exerted by gravity. The hydrostatic pressure can be determined from a control volume analysis of an infinitesimally small cube of fluid. Since pressure is defined as the force exerted on a test area (, with : pressure, : force normal to area , : area), and the only force acting on any such small cube of fluid is the weight of the fluid column above it, hydrostatic pressure can be calculated according to the following formula: where: For water and other liquids, this integral can be simplified significantly for many practical applications, based on the following two assumptions: Since

neg: Macula densa in dilation of the afferent arterioles, increasing the GFR due to greater blood flow to the glomerulus. It also results in the release of renin, which, through the renin–angiotensin system, causes constriction of the efferent arterioles, which ultimately increases hydrostatic pressure in the glomerulus. The process triggered by the macula densa helps keep the GFR fairly steady in response to varying artery pressure. Damage to the macula densa would impact blood flow to the kidneys because the afferent arterioles would not dilate in response to a decrease in filtrate osmolarity and pressure at the glomerulus would not be increased. As

neg: Edema Starling's equation can contribute to the formation of edemas either by an increase in hydrostatic pressure within the blood vessel, a decrease in the oncotic pressure within the blood vessel or an increase in vessel wall permeability. The latter has two effects. It allows water to flow more freely and it reduces the colloidal or oncotic pressure difference by allowing protein to leave the vessel more easily. When possible, treatment involves resolving the underlying cause. Treatment may also involve positioning the affected body parts to improve drainage. For example, swelling in feet or ankles may be reduced by having the

neg: Extracellular fluid interact at the level of the blood capillaries. The capillaries are permeable and water can move freely in and out. At the arteriolar end of the capillary the blood pressure is greater than the hydrostatic pressure in the tissues. Water will therefore seep out of the capillary into the interstitial fluid. The pores through which this water moves are large enough to allow all the smaller molecules (up to the size of small proteins such as insulin) to move freely through the capillary wall as well. This means that their concentrations across the capillary wall equalize, and therefore have no

neg: Well control pressure can be developed when the overburden has been stripped away, leaving the formation exposed at the surface. Depletion of original pore fluids through evaporation, capillary action and dilution produces hydrostatic gradients below 0.433 psi/ft (0.0979 bar/m). Subnormal pressures may also be induced through depletion of formation fluids. If Formation Pressure < Hydrostatic pressure then it is under pressured. If Formation Pressure > Hydrostatic pressure then it is over pressured . Fracture pressure is the amount of pressure it takes to permanently deform the rock structure of a formation. Overcoming formation pressure is usually not sufficient to cause fracturing. If

neg: Stayhealthy Stayhealthy Stayhealthy, Inc. is a privately held corporation that creates web-enabled healthcare monitoring products. It was founded in the dot-com era by CEO John Collins, and produces devices that monitor and measure such aspects of one's health like blood pressure, heart rate, body weight, body mass index, body composition, body fat (adipose tissue), visual perception, and calories burned. The company's current products include: the Body Composition Analyzer which reads an individual’s body composition with no appreciable difference from hydrostatic weighing or the DXA scan; a HealthCENTER Kiosk which has numerous configurations (Body Composition, Blood Pressure, Weight, Hearing, and Vision); Research

neg: Hydrostatic equilibrium Hydrostatic equilibrium In fluid mechanics, a fluid is said to be in hydrostatic equilibrium or hydrostatic balance when it is at rest, or when the flow velocity at each point is constant over time. This occurs when external forces such as gravity are balanced by a pressure-gradient force. For instance, the pressure-gradient force prevents gravity from collapsing Earth's atmosphere into a thin, dense shell, whereas gravity prevents the pressure gradient force from diffusing the atmosphere into space. Hydrostatic equilibrium is the current distinguishing criterion between dwarf planets and small Solar System bodies, and has other roles in astrophysics and planetary

neg: Pressure prism Pressure prism Hydrostatic pressure is the pressure exerted by a fluid at rest; for example on the sides of a swimming pool, glass of water or the bottom of the ocean. Its value at a given location within the fluid is the product the fluid density (ρ), the depth (d) and the forces applied by gravity (g), plus any background pressures, such as Atmospheric pressure. Hydrostatic Pressure on surfaces surrounding (or within) fluid volumes can be represented by the Pressure Prism, which is a useful visualization technique. Hydrostatic pressure increases linearly with depth. Generally it can be expressed by the

neg: Serum-ascites albumin gradient hydrostatic pressure (which pushes fluid out of the circulatory system). This balance is disturbed in certain diseases (such as the Budd–Chiari syndrome, heart failure, or liver cirrhosis) that increase the hydrostatic pressure in the circulatory system. The increase in hydrostatic pressure causes more fluid to leave the circulation into the peritoneal space (ascites). The SAAG subsequently increases because there is more free fluid leaving the circulation, concentrating the serum albumin. The albumin does not move across membrane spaces easily because it is a large molecule. A rare cause of ascites, with elevated SAAG, and without change in hydrostatic/osmotic pressure is

neg: Pathophysiology of heart failure reduces blood supply to the rest of the body. In chronic disease the reduced cardiac output causes a number of changes in the rest of the body, some of which are physiological compensations, some of which are part of the disease process: The increased peripheral resistance and greater blood volume place further strain on the heart and accelerates the process of damage to the myocardium. Vasoconstriction and fluid retention produce an increased hydrostatic pressure in the capillaries. This shifts the balance of forces in favor of interstitial fluid formation as the increased pressure forces additional fluid out of the blood,

neg: Soil mechanics vertical stress may be calculated by summing the product of the unit weight and thickness of all of the overlying layers. Total stress increases with increasing depth in proportion to the density of the overlying soil. It is not possible to calculate the horizontal total stress in this way. Lateral earth pressures are addressed elsewhere. If there is no pore water flow occurring in the soil, the pore water pressures will be hydrostatic. The water table is located at the depth where the water pressure is equal to the atmospheric pressure. For hydrostatic conditions, the water pressure increases linearly with

neg: Troposphere decreases with altitude. This is because the atmosphere is very nearly in hydrostatic equilibrium so that the pressure is equal to the weight of air above a given point. The change in pressure with altitude can be equated to the density with the hydrostatic equation where: Since temperature in principle also depends on altitude, one needs a second equation to determine the pressure as a function of altitude as discussed in the next section. The temperature of the troposphere generally decreases as altitude increases. The rate at which the temperature decreases, formula_2, is called the environmental lapse rate (ELR). The

neg: Transpiration increases the tension on the water menisci in the cell walls and decrease their radius and thus the tension that is exerted on the water in the cells. Because of the cohesive properties of water, the tension travels through the leaf cells to the leaf and stem xylem where a momentary negative pressure is created as water is pulled up the xylem from the roots. In taller plants and trees, the force of gravity can only be overcome by the decrease in hydrostatic (water) pressure in the upper parts of the plants due to the diffusion of water out of

neg: Oil well control to provide sufficient pressure to prevent an influx of formation fluid into the wellbore. If hydrostatic pressure is less than formation pressure, then formation fluids will enter the wellbore. If the hydrostatic pressure of the fluid in the wellbore exceeds the fracture pressure of the formation, then the fluid in the well could be lost. In an extreme case of lost circulation, the formation pressure may exceed hydrostatic pressure, allowing formation fluids to enter into the well. Secondary oil well control is done after the Primary oil well control has failed to prevent formation fluids from entering the wellbore. This

neg: Pleural effusion guide the procedure is now standard of care as it increases accuracy and decreases complications. After removal, the fluid may then be evaluated for: Definitions of the terms "transudate" and "exudate" are the source of much confusion. Briefly, transudate is produced through pressure filtration without capillary injury while exudate is "inflammatory fluid" leaking between cells. Transudative pleural effusions are defined as effusions that are caused by "systemic" factors that alter the pleural equilibrium, or Starling forces. The components of the Starling forces–hydrostatic pressure, permeability, and oncotic pressure (effective pressure due to the composition of the pleural fluid and blood)–are altered

neg: Oil well control of fluid that is static, or at rest, exerts pressure due to local force of gravity on the column of the fluid. The formula for calculating hydrostatic pressure in SI units (N/m²) is: All fluids in a wellbore exert hydrostatic pressure, which is a function of density and vertical height of the fluid column. In US oil field units, hydrostatic pressure can be expressed as: The 0.052 is needed as the conversion factor to psi unit of HSP. To convert these units to SI units, one can use: The pressure gradient is described as the pressure per unit length. Often

neg: Casing (borehole) necessary on longer drilling intervals where necessary drilling mud weight to prevent blowouts may cause a hydrostatic pressure that can fracture shallower or deeper formations. Casing placement is selected so that the hydrostatic pressure of the drilling fluid remains at a pressure level that is between formation pore pressures and fracture pressures. In order to reduce cost, a liner may be used which extends just above the shoe (bottom) of the previous casing interval and hung off downhole rather than at the surface. It may typically be 7", although many liners match the diameter of the production tubing. Few wells

neg: Waterproofing concrete. Within the waterproofing industry, below-ground waterproofing is generally divided into two areas: Tanking: This is waterproofing used where the below-ground structure will be sitting in the water table continuously or periodically. This causes hydrostatic pressure on both the membrane and structure, and requires full encapsulation of the basement structure in a "tanking membrane", under slab and walls. Damp proofing: This is waterproofing used where the water table is lower than the structure and there is good free-draining fill. The membrane deals with shedding of water and the ingress of water vapor only, with no hydrostatic pressure. Generally, this incorporates

neg: Hypsometric equation Hypsometric equation The hypsometric equation, also known as the thickness equation, relates an atmospheric pressure ratio to the equivalent thickness of an atmospheric layer under the assumptions of constant temperature and gravity. It is derived from the hydrostatic equation and the ideal gas law. The hypsometric equation is expressed as: where: In meteorology, formula_8 and formula_9 are isobaric surfaces. In altimetry with the International Standard Atmosphere the hypsometric equation is used to compute pressure at a given height in isothermal layers in the upper and lower stratosphere. The hydrostatic equation: where formula_11 is the density <nowiki>[kg/m</nowiki><nowiki>]</nowiki>, is used to generate

neg: Diving reflex effects that may be more severe during submersion due to hydrostatic pressure. Slowing the heart rate reduces the cardiac oxygen consumption, and compensates for the hypertension due to vasoconstriction. However, breath-hold time is reduced when the whole body is exposed to cold water as the metabolic rate increases to compensate for accelerated heat loss even when the heart rate is significantly slowed. The spleen contracts in response to lowered levels of oxygen and increased levels of carbon dioxide, releasing red blood cells and increasing the oxygen capacity of the blood. This may start before the bradycardia. "Blood shift" is a

neg: Glomerulus (kidney) exit into efferent arterioles rather than venules. The resistance of the efferent arterioles causes sufficient hydrostatic pressure within the glomerulus to provide the force for ultrafiltration. The glomerulus and its surrounding Bowman's capsule constitute a renal corpuscle, the basic filtration unit of the kidney. The rate at which blood is filtered through all of the glomeruli, and thus the measure of the overall renal function, is the glomerular filtration rate (GFR). The glomerulus is a tuft of small blood vessels called capillaries located within Bowman's capsule within the kidney. Glomerular mesangial cells structurally support the tufts. Blood enters the capillaries

neg: Well control pressures are not known accurately) the bit suddenly penetrates into an abnormal pressure formation resulting the hydrostatic pressure of mud become less than the formation pressure and cause a kick. When the gas is circulated to the surface, it expands and reduces the hydrostatic pressure sufficient to allow a kick. Although the mud density is reduced considerably at the surface, the hydrostatic pressure is not reduced significantly since the gas expansion occurs near surface and not at the bottom. The fourth cause of kick is poor well planning. The mud and casing programs have a great bearing on well control.

neg: Urinary system the blood, reabsorbing what is needed and excreting the rest as urine. In the first part of the nephron, Bowman's capsule filters blood from the circulatory system into the tubules. Hydrostatic and osmotic pressure gradients facilitate filtration across a semipermeable membrane. The filtrate includes water, small molecules, and ions that easily pass through the filtration membrane. However larger molecules such as proteins and blood cells are prevented from passing through the filtration membrane. The amount of filtrate produced every minute is called the glomerular filtration rate or GFR and amounts to 180 litres per day. About 99% of this filtrate

neg: Underwater diving is not greatly affected by immersion or variation in ambient pressure, but slowed heartbeat reduces the overall cardiac output, particularly because of the diving reflex in breath-hold diving. Lung volume decreases in the upright position, owing to cranial displacement of the abdomen from hydrostatic pressure, and resistance to air flow in the airways increases because of the decrease in lung volume. There appears to be a connection between pulmonary edema and increased pulmonary blood flow and pressure, which results in capillary engorgement. This may occur during higher intensity exercise while immersed or submerged. Cold shock response is the physiological response

neg: Hydrostatic test application and jurisdiction will usually reduce these risks to an acceptable level. Equipment. 1.Pressure gauges[1.5 to 4.0 times of test pressure] 2.Water tanks 3.Potable tanks 4.Pumbs for water filling and pressure 5.pressure gauges and temperature recorder. Hydrostatic test A hydrostatic test is a way in which pressure vessels such as pipelines, plumbing, gas cylinders, boilers and fuel tanks can be tested for strength and leaks. The test involves filling the vessel or pipe system with a liquid, usually water, which may be dyed to aid in visual leak detection, and pressurization of the vessel to the specified test pressure. Pressure

neg: Contrast bath therapy from the hydrostatic pressure from the water, not the variations in temperature. Contrast bath therapy Contrast bath therapy, also known as hot/cold immersion therapy, is a form of treatment where a limb or the entire body is immersed in hot (but not boiling) water followed by the immediate immersion of the limb or body in ice water. This procedure is repeated several times, alternating hot and cold. There does not yet appear to be any significant medical benefit from doing this, however. The theory behind contrast bath therapy is that the hot water causes vasodilation of the blood flow in

neg: Dialysis via the circuit back to the body. Ultrafiltration occurs by increasing the hydrostatic pressure across the dialyzer membrane This usually is done by applying a negative pressure to the dialysate compartment of the dialyzer. This pressure gradient causes water and dissolved solutes to move from blood to dialysate and allows the removal of several litres of excess fluid during a typical 4-hour treatment. In the United States, hemodialysis treatments are typically given in a dialysis center three times per week (due in the United States to Medicare reimbursement rules); however, as of 2005 over 2,500 people in the United States

neg: Shock (circulatory) while potassium ions leak out. As anaerobic metabolism continues, increasing the body's metabolic acidosis, the arteriolar smooth muscle and precapillary sphincters relax such that blood remains in the capillaries. Due to this, the hydrostatic pressure will increase and, combined with histamine release, this will lead to leakage of fluid and protein into the surrounding tissues. As this fluid is lost, the blood concentration and viscosity increase, causing sludging of the micro-circulation. The prolonged vasoconstriction will also cause the vital organs to be compromised due to reduced perfusion. If the bowel becomes sufficiently ischemic, bacteria may enter the blood stream, resulting

neg: Well control well. In oil and gas operations, it is represented mathematically as; "Hydrostatic pressure = pressure gradient × true vertical depth" or "Hydrostatic pressure = fluid density × conversion factor × true vertical depth" . The figure (not shown) shows two wells, well X and Y. Well X has measured depth of 9800 ft and a true vertical depth of 9800 ft while well Y has measured depth of 10380 ft and its true vertical depth is 9800 ft.To calculate the hydrostatic pressure of the bottomhole, the true vertical depth is used because gravity acts (pulls) vertically down the hole. The

neg: Hydrostatic shock (firearms) "The damage shown in these examples extends far beyond the tissue that is likely to direct contact with the projectile." (p. 150) In addition to providing examples from the WDMET data for indirect injury due to propagating shear and stress waves, Bellamy and Zajtchuck expresses an openness to the idea of pressure transients propagating via blood vessels can cause indirect injuries. "For example, pressure transients arising from an abdominal gunshot wound might propagate through the vena cavae and jugular venous system into the cranial cavity and cause a precipitous rise in intracranial pressure there, with attendant transient neurological dysfunction." (p.

neg: Hydrostatic test Hydrostatic test A hydrostatic test is a way in which pressure vessels such as pipelines, plumbing, gas cylinders, boilers and fuel tanks can be tested for strength and leaks. The test involves filling the vessel or pipe system with a liquid, usually water, which may be dyed to aid in visual leak detection, and pressurization of the vessel to the specified test pressure. Pressure tightness can be tested by shutting off the supply valve and observing whether there is a pressure loss. The location of a leak can be visually identified more easily if the water contains a colorant. Strength

neg: Well control as the pressure increase per unit of the depth due to its density and it is usually measured in pounds per square inch per foot or bars per meter.It is expressed mathematically as; "pressure gradient = fluid density × conversion factor". The conversion factor used to convert density to pressure is 0.052 in English system and 0.0981 in Metric system. Hydro means water, or fluid, that exerts pressure and static means not moving or at rest. Therefore, hydrostatic pressure is the total fluid pressure created by the weight of a column of fluid, acting on any given point in a

neg: Hydrostatic skeleton Hydrostatic skeleton A hydrostatic skeleton, or hydroskeleton, is a flexible skeleton supported by fluid pressure. Hydrostatic skeletons are common among simple invertebrate organisms. While more advanced organisms can be considered hydrostatic, they are sometimes referred to as hydrostatic for their possession of a hydrostatic organ instead of a hydrostatic skeleton. A hydrostatic organ and a hydrostatic skeleton may have the same capabilities, but they are not the same. Hydrostatic organs are more common in advanced organisms, while hydrostatic skeletons are more common in primitive organisms. As its name suggests, containing hydro meaning "water", being hydrostatic means that the skeleton or

neg: Hydrostatic stress Hydrostatic stress In continuum mechanics, a hydrostatic stress is an isotropic stress that is given by the weight of water above a certain point. It is often used interchangeably with "pressure" and is also known as confining stress, particularly in the field of geomechanics. Its magnitude formula_1 can be given by: where formula_3 is an index denoting each distinct layer of material above the point of interest, formula_4 is the density of each layer, formula_5 is the gravitational acceleration (assumed constant here; this can be substituted with any acceleration that is important in defining weight), and formula_6 is the height

neg: Hydrostatic shock (firearms) produce remote neural damage and produce incapacitation more quickly than blood loss effects. In arguments about the differences in stopping power between calibers and between cartridge models, proponents of cartridges that are "light and fast" (such as the 9×19mm Parabellum) versus cartridges that are "slow and heavy" (such as the .45 ACP) often refer to this phenomenon. Martin Fackler has argued that sonic pressure waves do not cause tissue disruption and that temporary cavity formation is the actual cause of tissue disruption mistakenly ascribed to sonic pressure waves. One review noted that strong opinion divided papers on whether the pressure

neg: Hydrostatic test and the test facility's identification mark. A simpler test, that is also considered a hydrostatic test but can be performed by anyone who has a garden hose, is to pressurise the vessel by filling it with water and to physically examine the outside for leaks. This type of test is suitable for containers such as boat fuel tanks, which are not pressure vessels but must work under the hydrostatic pressure of the contents. A hydrostatic test head is usually specified as a height above the tank top. The tank is pressurised by filling water to the specified height through a

neg: Hydrostatic shock (firearms) Partition bullet and Federal Cartridge Company’s decision to load this bullet in terms of the large tissue cavitation and hydrostatic shock produced from the frontal diameter of the expanded bullet. The North American Hunting Club suggests big game cartridges that create enough hydrostatic shock to quickly bring animals down. Hydrostatic shock (firearms) Hydrostatic shock is the controversial concept that a penetrating projectile (such as a bullet) can produce a pressure wave that causes "remote neural damage", "subtle damage in neural tissues" and/or "rapid incapacitating effects" in living targets. It has also been suggested that pressure wave effects can cause indirect

neg: Leak a hydrostatic test, sometimes called a pressure test. In a hydrostatic test, a system is pressurized with water to look for a drop in pressure or to see where it leaks out. Helium testing may be done to detect for any very small leakage such as when testing certain diaphragm or bellows valves, made for high purity and utra high purity service, requiring low leak rate capability. Helium and hydrogen have very small molecules which can go through very small leaks. Leak testing is part of the non-destructive test NDT portfolio that can be applied to a part to verify

neg: Siphon a siphon existed in the circulation of the giraffe. But further research in 2004 found that, "There is no hydrostatic gradient and since the 'fall' of fluid does not assist the ascending arm, there is no siphon. The giraffe’s high arterial pressure, which is sufficient to raise the blood 2 m from heart to head with sufficient remaining pressure to perfuse the brain, supports this concept." However, a paper written in 2005 urged more research on the hypothesis: The principle of the siphon is not species specific and should be a fundamental principle of closed circulatory systems. Therefore, the controversy

neg: Nephron to be filtered out of the blood plasma, and into the interior of Bowman's capsule, called Bowman's space. Only about a fifth of the plasma is filtered in the glomerulus. The rest passes into an efferent arteriole. The diameter of the efferent arteriole is smaller than that of the afferent, and this difference increases the hydrostatic pressure in the glomerulus. The Bowman's capsule, also called the glomerular capsule, surrounds the glomerulus. It is composed of a visceral inner layer formed by specialized cells called podocytes, and a parietal outer layer composed of simple squamous epithelium. Fluids from blood in the

neg: Orthopnea This leads to the pooling up of blood in the pulmonary circulation. The increased intra-parenchymal pulmonary intravascular pressure can also result in hydrostatic pressure related fluid exudation into the alveoli, thus causing pulmonary edema and further worsening shortness of breath. Thus, shortness of breath is commonly experienced after a reasonably short time lying near to flat for a person with left ventricular failure. This is different from the dyspnea experienced by some with lung parenchymal pathology (both restrictive and obstructive) when lying down, which is sudden and instead related to an acute change in diaphragmatic/accessory respiratory muscle mechanical advantage lost

neg: Pressure measurement the next. The oldest type is the liquid column (a vertical tube filled with mercury) manometer invented by Evangelista Torricelli in 1643. The U-Tube was invented by Christiaan Huygens in 1661. Hydrostatic gauges (such as the mercury column manometer) compare pressure to the hydrostatic force per unit area at the base of a column of fluid. Hydrostatic gauge measurements are independent of the type of gas being measured, and can be designed to have a very linear calibration. They have poor dynamic response. Piston-type gauges counterbalance the pressure of a fluid with a spring (for example tire-pressure gauges of comparatively

neg: Amoeboid movement the hydrostatic pressure that causes the bleb to extend. This is different from actin-driven locomotion where the protrusion created is by the actin polymerizing while remaining attached to the actomyosin cortex and physically pushing against the cell's barrier. During the bleb-driven amoeboid movement, the cytoplasmic sol-gel state is regulated. Blebbing can also be a sign of when a cell is undergoing apoptosis. It has also been observed that the blebs formed by motile cells undergo a roughly uniform life cycle that lasts approximately one minute. This includes a phase involving the initial outward expansion where the membrane breaks away from

neg: Oil well control in oil well control, pressure exerted by fluid is expressed in terms of its pressure gradient. The SI unit is pascals/metre. The hydrostatic pressure gradient can be written as: Formation pressure is the pressure exerted by the formation fluids, which are the liquids and gases contained in the geologic formations encountered while drilling for oil or gas. It can also be said to be the pressure contained within the pores of the formation or reservoir being drilled. Formation pressure is a result of the hydrostatic pressure of the formation fluids, above the depth of interest, together with pressure trapped in

neg: Pulmonary wedge pressure that pulmonary edema with normal PWP suggested a diagnosis of acute respiratory distress syndrome (ARDS) or non cardiogenic pulmonary edema (as in opiate poisoning). However, since capillary hydrostatic pressure exceeds wedge pressure once the balloon is deflated (to promote a gradient for forward flow), a normal wedge pressure "cannot " conclusively differentiate between hydrostatic pulmonary edema and ARDS. Physiological pressure: 6–12 mm Hg. Pulmonary wedge pressure The pulmonary wedge pressure or PWP, or cross-sectional pressure (also called the pulmonary arterial wedge pressure or PAWP, pulmonary capillary wedge pressure or PCWP, or pulmonary artery occlusion pressure or PAOP), is the pressure

neg: Yield surface follow from the convexity condition. A more precise formulation of the third constraints is proposed in. Parameters formula_109 and formula_110 describe the position of the intersection points of the yield surface with hydrostatic axis (space diagonal in the principal stress space). These intersections points are called hydrostatic nodes. In the case of materials which do not fail at hydrostatic pressure (steel, brass, etc.) one gets formula_111. Otherwise for materials which fail at hydrostatic pressure (hard foams, ceramics, sintered materials, etc.) it follows formula_112. The integer powers formula_113 and formula_114, formula_115 describe the curvature of the meridian. The meridian with formula_116

neg: Standing get sufficient blood supply. This, in turn, is caused by gravity, pulling the blood into the lower part of the body. Normally, the body compensates, but in the presence of other factors, e.g. hypovolemia, diseases and medications, this response may not be sufficient. There are medications to treat hypotension. In addition, there are many lifestyle advices. Many of them, however, are specific for a certain cause of orthostatic hypotension, e.g. maintaining a proper fluid intake in dehydration. Prolonged still standing significantly activates the coagulation cascade, called orthostatic hypercoagulability. Overall, it causes an increase in transcapillary hydrostatic pressure. As a result,

neg: Capillary pressure loss again leads to ice formation. Overall, Everett determined that frost heaving (analogous to the development of needle ice) occurs as a function of the pore size in the soil and the energy at the interface of ice and water. Unfortunately, the downside to Everett's model is that he did not consider soil particle effects on the surface. Capillaries in the circulatory system are vital to providing nutrients and excreting waste throughout the body. There exist pressure gradients (due to hydrostatic and oncotic pressures) in the capillaries that control blood flow at the capillary level, and ultimately influence the capillary

neg: Well control gradients are known, drilling operations may encounter abnormal pressure. Abnormal pore pressure is defined as any pore pressure that is greater than the hydrostatic pressure of the formation fluid occupying the pore space. It is sometimes called overpressure or geopressure. An abnormally pressured formation can often be predicted using well history, surface geology, downhole logs or geophysical surveys. Subnormal pore pressure is defined as any formation pressure that is less than the corresponding fluid hydrostatic pressure at a given depth. Subnormally pressured formations have pressure gradients lower than fresh water or less than 0.433 psi/ft (0.0979 bar/m). Naturally occurring subnormal

neg: Well control of the hole, the volume of the steel pipe being removed results in a corresponding decrease in wellbore fluid. Whenever the fluid level in the hole decreases, the hydrostatic pressure exerted by the fluid also decreases and if the decrease in hydrostatic pressure falls below the formation pore pressure, the well may flow. Therefore, the hole must be filled to maintain sufficient hydrostatic pressure to control formation pressure. During tripping, the pipe could be dry or wet depending on the conditions. The API7G illustrates the methodology for calculating accurate pipe displacement and gives correct charts and tables. To calculate the

neg: Hydraulic pump pumps. Axial piston swashplate pumps can be combined with a second pump, or with one or more gear pumps or vane pumps (the gear or vane pumps often serving as flush pumps for cooling larger units). Axial plunger pumps of the bent-axis design cannot be combined with other pumps. formula_2 where formula_7 where formula_13 where formula_17 where Hydraulic pump Hydraulic pumps are used in hydraulic drive systems and can be hydrostatic or hydrodynamic. A hydraulic pump is a mechanical source of power that converts mechanical power into hydraulic energy (hydrostatic energy i.e. flow, pressure). It generates flow with enough power

neg: Buoyancy they also have the same pressure distribution, and consequently the same total force resulting from hydrostatic pressure, exerted perpendicular to the plane of the surface of each side. There are two pairs of opposing sides, therefore the resultant horizontal forces balance in both orthogonal directions, and the resultant force is zero. The upward force on the cube is the pressure on the bottom surface integrated over its area. The surface is at constant depth, so the pressure is constant. Therefore, the integral of the pressure over the area of the horizontal bottom surface of the cube is the hydrostatic pressure

neg: Liquid water path Liquid water path Liquid water path - in units of [g/m²] is a measure of the total amount of liquid water present between two points in the atmosphere. LWP is an important quantity in understanding radiative transfer in the atmosphere. It is defined as the integral of liquid water content between two points in the atmosphere. For nadir observations and whole atmospheric column we have where is the liquid water mixing ratio and is the density of air (including water loading). The atmosphere is in approximate hydrostatic equilibrium and hydrostatic equation for atmospheric pressure is given by which gives where

neg: Hydrostatic shock (firearms) Hydrostatic shock (firearms) Hydrostatic shock is the controversial concept that a penetrating projectile (such as a bullet) can produce a pressure wave that causes "remote neural damage", "subtle damage in neural tissues" and/or "rapid incapacitating effects" in living targets. It has also been suggested that pressure wave effects can cause indirect bone fractures at a distance from the projectile path, although it was later demonstrated that indirect bone fractures are caused by temporary cavity effects (strain placed on the bone by the radial tissue displacement produced by the temporary cavity formation). Proponents of the concept argue that hydrostatic shock can

neg: Hydrostatic seal move apart and the seal begins to open. On the contrary, if the pressure is dropped and there is not enough pressure within the seal, the two seal faces come together and the Hydrostatic Seal begins to form. The flow rate of the system can also be controlled with great accuracy by limiting the amount of pressure within the seal. Pressure zones can be changed to create an equilibrium within the system that would allow less leakage in the overall system. The seals dual pressure zone helps maintain a constant pressure zone within the system. The constant pressure stabilizes the

neg: Oil well control the formation. Under formation pressure, there are 3 levels: normally pressured formation, abnormal formation pressure, or subnormal formation pressure. Normally pressured formation has a formation pressure that is the same with the hydrostatic pressure of the fluids above it. As the fluids above the formation are usually some form of water, this pressure can be defined as the pressure exerted by a column of water from the formation's depth to sea level. The normal hydrostatic pressure gradient for freshwater is 0.433 pounds per square inch per foot (psi/ft), or 9.792 kilopascals per meter (kPa/m), and 0.465 psi/ft for water with

neg: Siphon in the top reservoir, the liquid is under atmospheric pressure, and as one goes up the siphon, the hydrostatic pressure decreases (under vertical pressure variation), since the weight of atmospheric pressure pushing the water up is counterbalanced by the column of water in the siphon pushing down (until one reaches the maximum height of a barometer/siphon, at which point the liquid cannot be pushed higher) – the hydrostatic pressure at the top of the tube is then lower than atmospheric pressure by an amount proportional to the height of the tube. Doing the same analysis on the tube rising from

neg: Hydrostatic shock (firearms) characteristics, the question of whether the pressure waves satisfy the definition of "shock wave" is unimportant, and one can consider the weight of scientific evidence and various claims regarding the possibility of a ballistic pressure wave to create tissue damage and incapacitation in living targets. A number of papers describe the physics of ballistic pressure waves created when a high-speed projectile enters a viscous medium. These results show that ballistic impacts produce pressure waves that propagate at close to the speed of sound. Lee et al. present an analytical model showing that unreflected ballistic pressure waves are well approximated by