Cross-sectional areas values

Assume that this value was determined by experimentation, and that the velocity (above) was calculated using bottom screen or distributor plate cross-sectional area. Values for process air volume in the remaining product containers are estimates based on maintaining the same face velocity. Source Equipment dimensions courtesy Glatt Air Techniques, Inc. 

Fibres, containing derivatives of bis-aroilenbcnzimidazole, were subjected to ultra-violet light action of the lamp PRK-2. Mechanical properties of the fibres were determined depending on cross section area. Value of rupture stress (o) is the mean value of true rupture stress obtained from indexes of tearing machine. 

Because fault currents will flow around the earth fault-loop path, the measured resistance values must be low enough to allow the over-current protective device to operate quickly. For a satisfactory test result, the resistance of the protective conductor should be consistent with those values calculated for a line conductor of similar length and cross-sectional area. Values of resistance per metre for copper and aluminium conductors are given in Table 11 of the On Site Guide. The resistances of some other metallic containers are given in Table 4.2. 

Calibration procedure bases on rope specimens and corresponds to the Standard Pratice ASTM 1574. It takes a piece of the rope under test having a nominal metallic cross-section area (LMA=0) to set zero point of the instrument. Rope section with the LMA value known is used to set the second point of LMA calibration charactiristics. It is possible to use the air point calibration when there is no rope in a magnetic head (LMA=100%). 

A fractal surface of dimension D = 2.5 would show an apparent area A app that varies with the cross-sectional area a of the adsorbate molecules used to cover it. Derive the equation relating 31 app and a. Calculate the value of the constant in this equation for 3l app in and a in A /molecule if 1 /tmol of molecules of 18 A cross section will cover the surface. What would A app be if molecules of A were used ... 

Since capillary tubing is involved in osmotic experiments, there are several points pertaining to this feature that should be noted. First, tubes that are carefully matched in diameter should be used so that no correction for surface tension effects need be considered. Next it should be appreciated that an equilibrium osmotic pressure can develop in a capillary tube with a minimum flow of solvent, and therefore the measured value of II applies to the solution as prepared. The pressure, of course, is independent of the cross-sectional area of the liquid column, but if too much solvent transfer were involved, then the effects of dilution would also have to be considered. Now let us examine the practical units that are used to express the concentration of solutions in these experiments. 

Equation (9.28) describes the velocity with which a cylindrical shell of liquid moves through a capillary under stationary-state conditions. This velocity times the cross-sectional area of the shell gives the incremental volume of liquid dV which is delivered from the capillary in an interval of time At. The total volume delivered in this interval AV is obtained by integrating this product over all values of r ... 

The bulk fluid velocity method relates a blending quaUty Chemscale number to a quaUtative description of mixing (Table 3). The value of is equal to one-sixth of the bulk fluid velocity defined by pumping rate divided by cross-sectional area of the tank (4). 

The peripheral stiffening zone (tray ring) is generally 25 to 50 mm (1 to 2 in) wide and occupies 2 to 5 percent of the cross section, the fraction decreasing with increase in plate diameter. Peripheiy waste (Fig. 14-28) occurs primarily with bubble-cap trays and results from the inabihty to fit the cap layout to the circular form of the plate. Valves and perforations can be located close to the wall and little dead area results. Typical values of the fraction of the total cross-sectional area available for vapor dispersion and contact with the liquid for cross-flow plates with a chord weir equal to 75 percent of the column diameter are given in Table 14-6. 

AP is the pressure drop, cm of water Pg is the gas density, g/cm Ap is the total projected area of an entire row of baffles in the direction of inlet gas flow, cm" and At is the duct cross-sectional area, cm". The value jd is a drag coefficient for gas flow past inclined flat plates taken from Fig. 14-113, while L/ is the actual gas velocity, cm/s, which is related to the superficial gas velocity by U = L/g/cos 0. It must be noted that the angle of incidence 0 for the second and successive rows of baffles is twice the angle of incidence for the first row. Most of Calverts work was with 30° baffles, but the method correlates well with other data on 45° bafiles. 

For design, the slip velocity is derated to 70-80 percent of the calculated value to give some margin of safety this sets the design value of the continuous phase velocity (V ). The column cross sectional area (and therefore diameter) is set by QJVc- With the diameter set, the other dimensions can be set using the ratios given above. 

The lower cross sectional area curves relate to / = 50 Hz. For other frequencies l/Roc must be calculated by multiplying these values... 

Two particular test methods have become very widely used. They are the Vicat softening point test (VSP test) and the heat deflection temperature under load test (HDT test) (which is also widely known by the earlier name of heat distortion temperature test). In the Vicat test a sample of the plastics material is heated at a specified rate of temperature increase and the temperature is noted at which a needle of specified dimensions indents into the material a specified distance under a specified load. In the most common method (method A) a load of ION is used, the needle indentor has a cross-sectional area of 1 mm, the specified penetration distance is 1 mm and the rate of temperature rise is 50°C per hour. For details see the relevant standards (ISO 306 BS 2782 method 120 ASTM D1525 and DIN 53460). (ISO 306 describes two methods, method A with a load of ION and method B with a load of SON, each with two possible rates of temperature rise, 50°C/h and 120°C/h. This results in ISO values quoted as A50, A120, B50 or B120. Many of the results quoted in this book predate the ISO standard and unless otherwise stated may be assumed to correspond to A50.)... 

For natural draft fire tubes, the minimum cross-sectional area oi liu-fire tube is set by limiting the heat release density to 21,000 Biu/lir nr. At heat relea.se densities above this value, the flame may become utr.ia ble becriuse of insufficient air. Using this limit, a rninimuin fire eiv diamelei is established by ... 

---