Pressure graph

Figure 4. Logarithmic ion intensity-pressure graph of ethylene obtained by bombarding with H2S + of low kinetic energy...

The AUC is the area under the curve of the disintegration time vs. compression pressure graphs. 

A temperature-pressure graph showing the various states of matter is a phase diagram. Phase refers to a single homogeneous physical state. Different phases have either different compositions or different physical states. In the preceding figure, there are 3 phases with the same composition solid, liquid, and gas. 

The assumption that the heat of vaporization is constant is not necessarily valid. Also, at temperatures near the critical temperature, the assumption about tire molar volume of the liquid is invalid. Thus, a vapor-pressure graph of the type given in Figure 2-6 usually results in a line with some curvature over a long temperature range. 

AUCs are the area under curve from the disintegration time versus compression pressure graphs. (From Ref.t I)... 

The deviation of vapor pressure from Raoult s law can be represented graphically by comparing the mole fractions of solvents with their vapor pressures. Graph 1 below shows only the partial pressure of the solvent as its mole fraction increases. As predicted by Raoult s law, tire relationship is linear. Graph 2 shows the vapor pressure of an ideal solution and the individual partial pressures of each solvent. Notice that the partial pressures add at every point to equal the total pressure. This must be true for any solution. Graph 3 and 4 show the deviations of nonideal solutions. The straight lines are the Raoult s law predictions and the curved lines are the actual pressures. Notice that the partial pressures still add at every point to equal the total pressure. Notice also that a positive heat of solution leads to an increase in vapor pressure, and a negative heat of solution, to a decrease in vapor pressure. 

In Figure 6 the pressure graph at PI is given for a wide range of gas fractions k, 0-18.8%. The lower the gas fraction the higher the wave speed and maximal pressure. 

Compilation of vapor-pressure data for organic compounds data are correlated with the Antoine equation and graphs are presented. 

This is the essential characteristic for every lubricant. The kinematic viscosity is most often measured by recording the time needed for the oil to flow down a calibrated capillary tube. The viscosity varies with the pressure but the influence of temperature is much greater it decreases rapidly with an increase in temperature and there is abundant literature concerning the equations and graphs relating these two parameters. One can cite in particular the ASTM D 341 standard. 

Fig. 4. Fquilihrium vapor pressure of materials, where x indicates the melting point of the metal. The melting points for In and Sn ate off the graph at 156...

For very small AP, flux is linear with pressure. Figure 7 shows a graph of flux versus pressure. Curve A is the pure water flux from equation 1, curve B is the theoretical permeate flux (TPE) for a typical process. As the gel layer forms, the flux deviates from the TPF following equation 7 and curve D results. Changing the hydrodynamic conditions changes K and results in a different operating curve, curve C. 

The chart shown in Fig. 10-25 is for pure liqmds. Extrapolation of data beyond the ranges indicated in the graph may not produce accurate results. Figure 10-25 shows the variation of vapor pressure and NPSH reductions for various hydrocarbons and hot water as a function of temperature. Certain rules apply while using this chart. When using the chart for hot water, if the NPSH reduction is greater than one-half of the NPSH reqmred for cold water, deduct one-half of cold water NPSH to obtain the corrected NPSH required. On the other hand, if the value read on the chart is less than one-half of cold water NPSH, deduct this chart value from the cold water NPSH to obtain the corrected NPSH. 

In reality, the performance curve is easy to understand. It isn t rocket. science. The performance curve indicates that the pump will discharge a certain volume or flow (gpm) of a liquid, at a certain pressure or head (H), at an indicated velocity or speed, while consuming a specific quantity of horsepower (BHP). The performance curve is actually four curves relating with each other on a common graph. These four curves are ... 

Of the four elements of the TDH, the Hs and the Hp (elevation and pressure) exist whether the pump is running or not. The Hf and the Hv (frietion and velocity losses) can only exist when the pump is running. This being the ease, we can show the Hs and the Hp on the vertical line of the system curve at 0 gpm flow. The Hs is represented as a T on the graph below. For example, if the pump has to elevate the liquid 50 feet, the Hs is seen in Figure 8-2. 

The Hp also can exist with the pump running or off VVe can represent this value with an O or oval on the vertical line of the below graph. The Hp is added to and. stacked on top of the Hs. Let s say that our system is pumping cold water and requires 50 ft of elevation change and 10 psi of pressure change across the system. Now, our pump not only has to lift the liquid 50 ft, but it must also conquer 23 ft of Hp. Remember that 10 psi is 23.1 ft of Hp ... 

Let s continue with system curves. Up to this point, all elevations, temperatures, pressures and resistances in the drawings and graphs of systems and tanks have been static. This is not reality. Let s now consider the dynamic system curve and how it coordinates with the pump curve. 

What must be done is establish the maximum flow, and the minimum flow, and implement controls. Regarding filters, you ve got to establish the flow and pressure (resistance) that corresponds to the new, clean filter, and determine the flow and resistance that represents the dirty filter and its moment for replacement. These points must be predetermined. The visual graph of the system eurve with its dynamie resistances are seen in this example filtering and recirculating a liquid in a tank. Consider the following graphs (Figures 8-18 and 8-19). 

The graph in figure 3.4.4 shows the pressure drop over 5.6 mm 0 glass balls. Generated pressure was not significantly different on these larger balls than it was over the 0.2 mm powder. 

The GPSA Engineering Data Boole provides the following four graphs (Figures 2-5) showing the effect of altitude, inlet pressure loss, exhaust pressure loss, and ambient temperature on power and heat rate. 

Loeb used Lapple s compressible flow work, techniques, and reasoning to develop graphs useful for direct calculations between tw o points in a pipe. Lapple s graphs were designed for pressure drop estimations for flow from a large vessel into a length of pipe (having static velocity in the reservoir). 

Figure 4. Graph Showing Change of Pressure Along a GC Column for Different Inlet/Outlet Pressure Ratios...

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