Selected Conversion Factors

The prefixes should be attached directly to the SI base unit e.g., kilogram, millisecond, gigameter, etc. Similarly, the abbreviations attach directly to the abbreviation for the SI units e.g., cm, Mg, mK, etc. Do not use two or more of the SI units. Although kilogram is the normal base unit for mass, the prefixes are added to gram (g), not kilogram (kg). 

Freezing Point of Water Celsius = 0 deg., Fahr. = 32 degrees Boiling Point of Water. Celsius = 100 deg., Fahr. = 212 degrees 

Btu/cubic foot 37.25895 Kiloj oule/cubic meter 

Cubic foot/minute 472.0 Cubic centimeters/second 

Kilogram/square centimeter 14.22 Pounds/square inch 

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Ca.ta.lysts, Catalyst performance is the most important factor in the economics of an oxidation process. It is measured by activity (conversion of reactant), selectivity (conversion of reactant to desked product), rate of production (production of desked product per unit of reactor volume per unit of time), and catalyst life (effective time on-stream before significant loss of activity or selectivity). 

Chemical Flowsheet Basic unit operation selection with flow rates, conversion factors, temperatures, pressures, solvents and catalyst selection Process synthesis route Laboratory and pilot scale trials Knowledge of existing processes... 

An example of this is the commercial process for preparing puru-xylene, the precursor to terephthalic acid, which is polymerised to give polyjethy-lene terephthalate) (PET). In this case, the mixture of xylenes obtained from crude oil is reacted in a zeolite (known as HZSM5). The relative rates of diffusion in and out of the pores are sufficiently different (by a factor of about ten thousand) to allow the extremely efficient and selective conversion of all the isomers to the desired paia isomer, which is the narrowest and can thus move through the structure most rapidly (Figure 4.3). 

To overcome this limitation, a series of images of an entire field of cells can be obtained, then the waves can be visualized when the images are played back in rapid sequence. Specific lines of analysis can then be chosen after the experiment is completed. The line is selected to be perpendicular to the wave front (that is, along the direction of propagation). As before, the lines are stacked on top of one another, yielding a reconstructed line scan that contains all the information of a true line scan. The leading edge of the Ca2+ wave appears on the line scan as a sharp line with a constant slope. Since the slope is distance/time, appropriate conversion factors allow true speeds to be obtained in jUm/s. 

Table 1. Conversion factors and physical constants Table 2. Thermochemical data for selected species Table 3. Thermochemical data for species included in reaction list of Appendix C...

Receptor processes must also be selective. You can usually carry on a conversation with one person at a party if the overall noise is not too loud because you can select his or her speech sounds over the many speech sounds available in the room and focus on some to get the desired information. The reception process and the selection process in the ear do not involve the same mechanical and neural parts, but for the sake of simplicity, we will talk of reception processes as including the selectivity factor and the conversion factor. 

The international system of units is described in detail in NIST Special Publication 81l,1 and lists of physical constants and conversions factors of selected unit conversions1 5 are given in the following tables. The conversions are presented in matrix format when all of the units are of a convenient order of magnitude. When some of the unit conversions are of tittle value (such as the conversion between metric tons and grains), tabular form is followed, with the less useful units omitted. 

This method accomplishes the extraction, isolation, and infrared identification of a number of common chlorinated insecticides when present at concentrations of 1-2 p.p.m. or more in fish tissues. In the course of testing the method, certain related observations (noted in Table II) were provided by analyzing fish which were fed insecticides under laboratory conditions. Aldrin was converted largely to dieldrin in both muscle tissue and viscera of a fish exposed to aldrin for 22 days. However, where death occurred in 5 days after a massive dose, the conversion was very slight in the viscera. Heptachlor underwent a significant conversion to heptachlor epoxide, and DDT to DDE. There was also a selective concentration factor—e.g., technical heptachlor (containing y-chlordan) showed a considerably higher ratio of y-chlordan to heptachlor in the fish than in the crude insecticide. Likewise, DDD in... 

Table 7.1 Summary of selected nitrogen (NOj", NO2, NH +, urea, dissolved free amino acids [DFAA], DON) uptake rates from the major ocean basins, and upwelling, coastal and estuarine systems using tracer techniques. Rates were converted to common units (nmol N L" using data provided in the original publication or using conversion factors specified in the footnotes... 

Various and random membrane information has been tabulated as a matter of course in previous sections and tables. For the calcula-tional purposes here, a representative set of comparative values follows for a membrane of low selectivity between the key components components i and j, with operating pressure levels in the ratio of 3 to 2. The units are unstated inasmuch as the entities calculated will absorb the conversion factors— which are not necessary for calculating the degree of separation and are therefore immaterial except in determining membrane area. The procedure follows that provided in Example 3.1 of Floffman (2003). 

To determine the number of atoms, select the conversion factor that will take you from the amount in moles to the number of atoms. 

Make sure to select the correct conversion factor so that units cancel to give the unit required in the answer. 

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