Pressure Value

Critical Velocity and Limiting Velocity of Detonation. See Detonation Velocity, Critical and Limiting 

Cruciform Luminosity Produced by Detonation of Explosive Cartridges of Square Cross Section 

Crystal Size Influence on Detonation Velocity. See Detonation Velocity - Crystal Size Relationship 

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In another type of reference plot the temperature of a property of compound A is plotted vs the temperature of the reference substance at equal vapor pressures values. 

The constants Cj and C9 are both obtained from Fig. 2-40 Ci, usually from the saturated liquid line and C2, at the higher pressure. Errors should be less than 1 percent for pure hydrocarbons except at reduced temperatures above 0.95 where errors of up to 10 percent may occur. The method can be used for defined mixtures substituting pseiidocritical properties for critical properties. For mixtures, the Technical Data Book—Fehvleum Refining gives a more complex and accurate mixing rule than merely using the pseiidocritical properties. The saturated low pressure value should be obtained from experiment or from prediction procedures discussed in this section for both pure and mixed liquids. 

For prediction of the vapor viscosity of gaseous bydi ocarbons and mixtures of bydi ocarbons at nigb pressui es (not applicable to nonhydrocarbon gases) above a 7, of 0.6, low pressure values are calculated from Eq. (2-97) and/or (2-100) and then corrected for pressure by the method of Dean and StieF given by Eq. (2-102). 

For example, in rotary vacuum dryers it is possible to prevent the formation of explosible dust-air mixtures by setting and monitoring a certain partial vacuum (negative pressure). This pressure value must be determined by experiment for each type of dust. With pressures of less than O.I bar, in general, hazardous effects of dust explosions need not be anticipated. If the vacuum system malfunctions, the partial vacuum must be released by inert gas and the instaUation shut down. 

With all nonconventional valves, the maximum allowable back pressure may be taken as high as 50 percent of the valve set pressure. This pressure value... 

An external node represents a boundary node, i.e., a fixed pressure value or a location on the building facade which is linked to a specific set of vvind pressure coefficients for this location (a set of values for different wind directions Q ). The pressure at such a location e is then given by wind velocity at reference level p, air density) ... 

Ar the start of the iteration, an initial guess for the zone pressures can be found by using linearized pressure-airflow relations for the links, zero pressure values, or values from the previous time step. 

Data are available only for simple building geometries. In Allard," a tool for the calculation of wind pressure coefficients for simple geometries is made available, and another tool is described in Knoll et al. Existing wind pressure data have to be examined carefully, because many data represent peak pressure values needed for static building analysis. Real cases with obstructions and buildings in the close surroundings are difficult to handle. Wind-tunnel tests on scale models or CFD analysis will be required. 

It has been a persistent characteristic of shock-compression science that the first-order picture of the processes yields readily to solution whereas second-order descriptions fail to confirm material models. For example, the high-pressure, pressure-volume relations and equation-of-state data yield pressure values close to that expected at a given volume compression. Mechanical yielding behavior is observed to follow behaviors that can be modeled on concepts developed to describe solids under less severe loadings. Phase transformations are observed to occur at pressures reasonably close to those obtained in static compression. 

Fig. 5.1. The electrostatic configurations of the Neilson-Benedick three-zone model describe a piezoelectric solid subject to elastic-inelastic shock deformation which divides the crystal into three distinct zones. Zone 1, ahead of the elastic wave, is unstressed. Zone 2 is elastically stressed at the Hugoniot elastic limit. Zone 3 is isotropically pressurized to the input pressure value (after Graham [74G01]).

It is inadvisable to extrapolate outside the regions given in Figure 9.7. For high scaled-pressure values (i.e., scaled energy larger than 0.8), method 3 should be used. 

Figure 12-143 shows the individual static pressure curve Pf and total pressure curve Pff If pressure losses between the two fans are neglected (and they should he very low for good design), the combined total pressure curve is twice the value of curve Pft, 2 Pff The new operating static pressure also should be twice the individual total pressure value minus the velocity pressure, 2 p — p for identical fans, the new operating static pressure is equal to 2 p + Pf. The operation of the series fans will be along the system resistance curve, and the resultant point of operation will be at the intersection of the system curve with the curve for (2 pa — Pfv). 

Using actual cfm at intake conditions to fan and equivalent static pressure (2), read manufecturers rating tables for bhp and rpm. Note that if exact cfm or pressure value is not listed in tables, it may be reached by (a) interpolation as previously described for approximation or (b) by using fan laws to correct one set of table values. 

Pressure values along the top of each table are differential pressures across the two cylinder ports. This is the pressure to just balance the load and not the pressure that must be produced by the system pump. There will be circuit flow losses in pressure and return lines due to oil flow and these will require additional pressure. When designing a system, be sure to allow sufficient pump pressure, about 25 per cent to 30 per cent, to supply both the cylinder and to satisfy system flow losses. 

A different reference level, absolute pressure, is used to obtain the total pressure value. Absolute pressure is the total pressure, i.e., gage and atmospheric, and is expressed as psia or pounds per square inch absolute. To obtain absolute pressure, simply add the value of atmospheric pressure (14.7 psi at sea level) to the gage pressure reading. 

L. L. Blyler and T. K. Kwei [39] proposed the direct opposite (to 4). In their reasoning, they proceeded from the known and generally acceptable Doolittle equation, which puts liquid viscosity in exponential dependence on the inverse value of the free volume of the latter. According to [39], gas has a volume of its own, the value of which it contributes to the free volume of the polymer when it dissolves therein as a result, viscosity falls. The theoretical formula obtained by the authors was experimentally confirmed in the same work. The authors measured pressure values at the entrance of cylindrical capillaries, through which melts of both pure polyethylene, and polyethylene with gas dissolved in it, extruded at a constant rate. 

The higher category applies, if systolic and diastolic blood pressure values of a patient fall into different categories. 

Barrel Pressure, Value of pressure induceu by the proplnt gases at any barrel position and at the time that the bullet bypasses the particular position. May be ealed with the help of the simultaneous chamber pressure... 

Maximum Barrel Pressure. Value of pressure induced by the proplnt gases at a barrel position just passed by the bullet, and at a time that peak pressure exists in the chamber... 

For a pure substance, having three phases in equilibrium results in a triple point that is invariant. When pure solid, liquid, and gaseous water are in equilibrium, the temperature is fixed at a value of 273.16 K, and the pressure of the gas is fixed at the vapor pressure value (0.6105 kPa). 

As an example, the molar constant-volume heat capacity of argon is 12.8 J-K 1-mol 1, and so the corresponding constant-pressure value is 12.8 + 8.3... 

Calculation of the second-order rate constant of carbonylation, kg, and the equilibrium constant, K = [t-C4H9CO+]/[t-C4H ][CO] = A c/fcD> requires knowledge of the concentration of CO. The constant a in Henry s law Pco = [CO] was determined to be 5-3 litre mole atm in HF—SbFs (equimolar) and 53 litre mole atm in FHSOs—SbFs (equimolar) at 20°C. From the ratio [t-C4HBCO+]/[t-C4HJ"] at a known CO pressure, values for k and K were obtained. The data are listed in Table 1, which includes the values for the rate and equilibrium constants of two other tertiary alkyl cations, namely the t-pentyl and the t-adamantyl ions (Hogeveen et al., 1970). 

T, 0.1 MPa) condition to be calculated, t is then known for any P and T corresponding to an ambient pressure value of TV. This method is quite powerful because it allows determination of relaxation times for any thermodynamic condition T, P, or V) provided only that the same value of T had been measured at ambient pressure. 

A variant of this calculation method for S consists in using equation (2) by inserting the experimental vapour pressure values, provided there is serious reason to believe that these experimental values are reliable. In the opposite case, one would inevitably suffer the consequences of the disadvantage mentioned above. 

By attribution of the group in the majority, ie group 3 and above, all the calculations based on rule 5 lead to a result that is perfectly in line with the values at 30 and 50°C and to the rejection of the 173 mbar value at 20°C, the 145 mbar value being perfectly consistent with the other values at different temperatures. This technique also enables determination of so-called reliable pressure values. 

Rule 7. An experimental distribution of pressure values will be regarded as reliable when attribution of a same group is made when calculating S using these values, or when different calculations of S lead to values that are very close to this. 

The result allows clear rejection of the 267°C value and possibly allows retention of either the estimated 280-282 value or the 284-287°C experimental interval. In any case, to go further, it will be seen the < 0.013 value is the only one in line with the method shown. The 15(50) pressure value is obviously unrealistic as simple comparison with the boiling point under 10 mmHg (ie under 13.3 mbar) pressure demonstrates. 

It is necessary to use values of vapour pressure in order to be able to deal with the last stage since boiling point values under reduced pressure are not available. The selected vapour pressure value is the only one that is coherent since the others would provide a value of S very far outside the entropic domain. The calculated value of S is already greater than the maximal value Sg (as in the case of 2-propanol), a point that will be returned to later. 

When there are several boiling point values under reduced pressure or experimental pressure values, preference is given to the estimates from data measured at temperatures that come closer to the temperature at which the estimation is carried out. 

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