Table or Chart

A really nice way to determine what s going on with a word problem is to make a list of different possibilities and see what fits in the list or what pattern forms. Patterns often suggest a formula or equation the values in the listing sometimes even provide the exact answer. Just as with pictures, making a chart is a way of visualizing what s going on. 

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Sling psychrometer An instrument used to measure the dry-bulb and wet-bulb temperatures of the air, from which the humidity of the air can be determined by means of calculations, tables, or charts. 

Note, most manufacturers tables or charts give SCFH capacities at 14.7 psia and 60°F, and these must be corrected by the gas laws to the artwa/volume at flowng conditions in order to represent the actual performance of the system. The tables or charts of the manufacturers read in SCFH for selected relief device setting and for tank pressure, expressed as air at SCFH (see Figures 7-37A and 37B). 

The capacity of a valve as read from a manufacturer s table or chart is 45,000 cubic feet per hour oifree air (14.7 psia and 60°F). What is the capacity of the valve in terms of the vapors expected to pass through the valve under the rated conditions at the same setting If methanol is in the tank at 55°F... 

Read manufacturer s capacity tables or charts to select model and size of pressure relief, reading table to closest capacity, but toward larger size if in between. Consult manufacturer for final selection. 

Read Rvalue for toluene from tables or charts. ... 

Cool 7,936 Ib/hr ammonia from 292°F to 105°F and condense at this point. Pressure is 228.9 psia. Reading ammonia superheated vapor tables (or chart) ... 

The second method can be applied to mixtures as well as pure components. In this method the procedure is to find the final temperature by trial, assuming a final temperature and checking by entropy balance (correct when ASp t, = 0). As reduced conditions are required for reading the tables or charts of generalized thermodynamic properties, the pseudo critical temperature and pressure are used for the mixture. Entropy is computed by the relation. See reference 61 for details. ... 

Relative humidity is usually considered only in connection with atmospheric air, but since it is unconcerned with the nature of any other components or the total mixture pressure, the term is applicable to vapor content in any problem. The saturated water vapor pressure at a given temperature is always known from steam tables or charts. It is the existing partial vapor pressure which is desired and therefore calculable when the relative humidity is stated. 

Suitable conversion tables are available (ASTM D341), and each table or chart is constructed such that for any given petroleum or petroleum product, the viscosity-temperature points result in a straight line over the applicable temperature range. Thus, only two viscosity measurements need be made at temperatures far enough apart to determine a line on the appropriate chart from which the approximate viscosity at any other temperature can be read. 

When creating a table or chart, designate a variable to represent a part of the problem, and see what the results are as you systematically change that variable. For example, if you re trying to find two numbers the product of which is 60 and the sum of which is as small as possible, let the first number be x. Then the other number is Add the two numbers together to see what you get. Table 1-2 shows the different values for the two numbers and the sum — if you stick to whole numbers. 

When making a table or chart, you want to be as systematic as possible so you don t miss anything - especially if that anything is the correct answer. After you ve determined a variable to represent a quantity in the problem, you need to go up in logical steps — by ones or twos or halves or whatever is appropriate. In Table 1-2, in the preceding section, you can see that I went up in steps of 1 until I got to the 6. One more than 6 is 7, but 7 doesn t divide into 60 evenly, so I skipped it. Even though the work isn t shown here, I mentally tried 7, 8, and 9 and discarded them, because they didn t work in the problem. When you re working with more complicated situations, you don t want to skip any steps — show them all. 

Create a table or chart with the variables and their descriptions down one side and the different relationships (prices, numbers, and so on) across the top. 

Don t use multiple columns, tables, or charts within your document. Instead of tabs, indent text using spaces. 

This equation may be used for any gas or vapor and for any process. Some knowledge of thermodynamics is required in order to evaluate the E terms, and in the case of vapors it is necessary to use vapor tables or charts, because their properties cannot be expressed by any simple equations. 

In these equations f 2 is the value of enthalpy after a frictionless adiabatic expansion from px to p2. It may be obtained from vapor tables or charts and is very convenient for vapors. The discussion of such tables and their use is outside the scope of this text and is strictly in the field of thermodynamics, but for a gas Ey - E2 = cp(T - T2), where T2 = T, [p2/p2 (k - l)]/k. For compressible fluids, p must be absolute pressure. 

Calculate from enthalpy tables or charts the heat absorbed, AH, when the indicated equilibrium gases are heated from the reference temperature, on which the enthalpy data are based, to the assumed combustion temperature Te. 

Determine the view factors from the very long grooves shown in Fig. P13-12 10 the. surroundings without using any view Factor tables or chart.s. Neglect ctid effects. 

In this problem we will use A/// and A7f in the calculations to illustrate how to calculate the overall enthalpy change when a table or chart is not available. Recall that enthalpy is a state function. Consequently, we can choose any convenient path between the initial and final state for the calculations. Figure E4.18 shows two different possible paths to be used to calculate A f. Which should be selected The answer is the one with the best data. Usually, phase transitions are evaluated at the melting point (for a solid) and the normal boiling point of 1 atm (for a liquid) because you can easily find tabulated data at those temperatures, but any temperature would suffice. We will choose the path A—> for which the data are... 

Qualitative analysis depends on identification of the peaks on the video display of the MCA, which shows the counts accumulated vs. x-ray energy. The analyst should have a table or chart of the energies of all K and L lines arranged consecutively, as in Vol. 4 of [G.ll]. (Only ATa-line energies are listed in Appendix 7.) Or these data may be stored in the memory of the MCA, to be retrieved when needed. 

The one phase of solids mixing which has been treated at length in the literature is the description of equipment. In textbooks, reference books, and review articles, pictures of equipment are shown and tables or charts given, which list suitable equipment for various applications. Also, details of machines, diagrams of their shapes, and practical construction data are available, including approximate power requirements. 

Although Ey and are analogous to fj. and v, respectively, in that all these quantities are coefficients relating shear stress and velocity gradient, there is a basic difference between the two kinds of quantities. The viscosities n and v are true properties of the fluid and are the macroscopic result of averaging motions and momenta of myriads of molecules. The eddy viscosity and the eddy diffusivity are not just properties of the fluid but depend on the fluid velocity and the geometry of the system. They are functions of all factors that influence the detailed patterns of turbulence and the deviating velocities, and they are especially sensitive to location in the turbulent field and the local values of the scale and intensity of the turbulence. Viscosities can be measured on isolated samples of fluid and presented in tables or charts of physical properties, as in Appendixes 8 and 9. Eddy viscosities and diffusivities are determined (with difficulty, and only by means of special instruments) by experiments on the flow itself. 

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