Word Finder - pressures

definition

A pressing; a force applied to a surface.

example

Apply pressure to the wound to stop the bleeding.

definition

A contrasting force or impulse of any kind

example

the pressure of poverty; the pressure of taxes; the pressure of motives on the mind; the pressure of civilization.

definition

Distress.

example

She has felt pressure lately because her boss expects her to get the job done by the first.

definition

Urgency

example

the pressure of business

definition

Impression; stamp; character impressed.

definition

The amount of force that is applied over a given area divided by the size of this area.

definition

To encourage or heavily exert force or influence.

example

Do not let anyone pressure you into buying something you do not want.

It is generally taken as constant, but its value at moderate pressures is difficult to determine.

The reader will be able to make out the simultaneous motions and pressures at various points.

It was found, however, that when Oxyacetylene using acetylene under low pressures, the burner tip blowpipe.

But if hinges are introduced at crown and springings, the calculation of the stresses in the arch ring becomes simple, as the line of pressures must pass through the hinges.

A curve tangential to all the sides of the polygon is the line of pressures.

The foreign prisoners debacle has led to further pressures.

It has been found that variations in barometric pressure affect the flash-point and accordingly corrections have to be made in obtaining strictly comparative results at different pressures.

As an example of one of the few cases where a complete solution is possible, we may take the comparatively simple case equation (17), already considered, which is approximately true for the majority of vapours at moderate pressures.

The difference in the weights corresponds to the volume of gas at a pressure equal to the difference of the recorded pressures.

The aggregate amount of these pressures is clearly the sum of the momenta, normal to the boundary, of all molecules which have left dS within a time dt, and this will be given by expression (pp), integrated with respect to u from o to and with respect to v and w from - oo to +oo, and then summed for all kinds of molecules in the gas.

As to anemometer pressures, it should be observed that the recorded pressure is made up of a positive front and negative (vacuum) back pressure, but in structures the latter must be absent or only partially developed.

The most fundamental experimental confirmation that the theory of the aether has received on the optical side in recent years has been the verification of Maxwell's proposition that radiation exerts mechanical force on a material system, on which it falls, which may be represented in all cases as the resultant of pressures operating along the rays, and of intensity equal at each point of free space to the density of radiant energy.

They will alter the shape of mineral particles by broadening them in a direction at right angles to the principal pressures, while they are thinned in the direction in which the pressure acted.

Pressures Observed In A Closed Vessel With Various Explosives 20 15 s n 05 10 -15 20 25 30 35 40.45 50.

In air and other gases, at ordinary pressures, the dispersion is very small, because the refractivity is small.

For the investigation of the spectra of gases at reduced pressures the so-called Plucker tubes (more generally but incorrectly called Geissler tubes) are in common use.

In the original experiments 2 the pressures could only be increased to 15 atmospheres, but in a more recent work Humphreys,' and independently Duffield, were able to use pressures up to ioo atmospheres.

We have first the Doppler effect, which, according to Michelson's experiment, is the chief cause of the limit at very low pressures, but it is too small to account for the widening which is now under discussion.

Having felt reciprocal pressures in touch, I infer similar pressures between myself and the external world.

There is none in the subsidiary senses, because none of them perceives the pressures exerted on them.

But the primary sense of touch perceives one bodily member causing pressure on another, reciprocally, within the organism, from which we infer similar particular pressures caused between the organism and the external world; but without needing the supposed stupendous belief and assumption of the uniformity of Nature, which is altogether ignored in the inferences of the ordinary man.

In practice the time required to reach these various conditions of equilibrium would be too great for experimental demonstration, but the theoretical consideration of vapour pressures is of fundamental importance.

Now measurements of osmotic properties of these solutions show that their osmotic pressures are abnormally great and that, at extreme dilution, the ratio of their osmotic pressures to that of equivalent solutions of non-electrolytes is equal to the number of ions indicated by the electrolytic properties.

The osmotic pressure (defined as the difference in the hydrostatic pressures of the solution and solvent when their vapour pressures are equal and they are consequently in equilibrium through a perfect semi-permeable membrane) may also depend on the absolute values of the hydrostatic pressures, as may the vapour pressure of the liquids.

The osmotic pressure Po is the difference of the hydrostatic pressures P' and P of the solution and the solvent when their vapour pressures are equal.

The relation between the equilibrium pressures P and P' for solution and solvent corresponding to the same value po of the vapour pressure is obtained by integrating the equation V'dP' = vdp between corresponding limits for solution and solvent.

J p J where p and p' are the vapour pressures of solvent and solution each under its own vapour pressure only.

From this equation the osmotic pressure Po required to keep a solution in equilibrium as regards its vapour and through a semi-permeable membrane with its solvent, when that solvent is under its own vapour pressure, may be calculated from the results of observations on vapour pressure of solvent and solution at ordinary low hydrostatic pressures.

Hartley, who also determined the vapour pressures by passing a current of air successively through weighed vessels containing solution and water respectively.

The difference in the lowering of vapour pressures dp - dp' may be put equal to VdP/v, where P is the osmotic pressure, and V the specific volume of the solvent.

Let us assume that the ratio p/p' of the vapour pressures of the solvent and solution is equal to the ratio of the number of free molecules of solvent to the whole number of molecules in the solution.

If there are n molecules of solute to N of solvent originally, and each molecule of solute combines with a molecule of solvent, we get for the ratio of vapour pressures p/p'=(N - an)/(N - an+n), while the relative lowering of vapour pressure is (p - p')/p=n/(N - an).

He thus enunciated the law of the expansion of gases, stated some months later by Gay-Lussac. In the two or three years following the reading of these essays, he published several papers on similar topics, that on the "Absorption of gases by water and other liquids" (1803), containing his "Law of partial pressures."

Within the crust of the earth, whether by the contraction of the interior or in any other way, tangential pressures were set up. Since the crust is not of uniform strength throughout, only the weaker portions yielded to the pressure; and these were crumpled up against the more resisting portions and sometimes were pushed over them.

Even hard steel is treated in this way to form tubes for the highest hydraulic and steam pressures.

The ice was however much heavier, and in the terrific pressures which occurred the " Endurance " was crushed on Oct.

Employing Pressures Between 7 And 27 Atmospheres, He Found That The Specific Heat Of Air Between 10 And Ioo C. Increased Very Slightly With Increase Of Density, But That Of Co 2 Increased Nearly 3% Between 7 And 21 Atmospheres.

For Such Gases, Assuming A Constant Ratio Of Rotation To Translation, The Specific Heat At Low Pressures Would Be Very Nearly Constant.

P. Pfeffer (Osmotische Untersuchungen, Leipzig, 1877) was the first to obtain satisfactory measurements of osmotic pressures of cane-sugar solutions up to nearly I atmosphere by means of semi-permeable membranes of copper ferrocyanide.

The highest pressures recorded for cane-sugar are nearly three times as great as those given by van't Hoff's formula for the gas-pressure, but agree very well with the vapour-pressure theory, as modified by Callendar, provided that we substitute for V in Arrhenius's formula the actual specific volume of the solvent in the solution, and if we also assume that each molecule of sugar in solution combines with 5 molecules of water, as required by the observations on the depression of the freezing-point and the rise of the boiling-point.

It was applied in the most perfect manner by Regnault to determine the latent heats of steam and several other vapours at high pressures.

It is evident that this is a very delicate method of determining the wetness z, but, since with dry saturated steam at low pressures this formula always gives negative values of the wetness, it is clear that Regnault's numerical coefficients must be wrong.

The method of deducing the specific heat from Regnault's formula for the variation of the total heat is evidently liable in a greater degree to the objections which have been urged against his method of determining the specific heat, since it makes the value of the specific heat depend on small differences of total heat observed under conditions of greater difficulty at various pressures.

In order to correct this equation for the deviations of the vapour from the ideal state at higher temperatures and pressures, the simplest method is to assume a modified equation of the Joule-Thomson type (Thermodynamics, equation (17)), which has been shown to represent satisfactorily the behaviour of other gases and vapours at moderate pressures.

The rate of variation of the latent heat at low pressures is equal to S-s, where s is the specific heat of the liquid.

It was employed as a purely empirical formula by Bertrand and Barus, who calculated the values of the coefficients for several substances, so as to obtain the best general agreement with the results of observation over a wide range, at high as well as low pressures.

The true application of the formula is to low pressures, at which it is very accurate.

The close agreement found under these conditions is a very strong confirmation of the correctness of the assumption that a vapour at low pressures does really behave as an ideal gas of constant specific heat.

This case has important practical applications; for instance we may use the method to find the pressures on the supports of a beam loaded in any given manner.

The pressures of the beam on the supports are of course represented by ED, AE.