Conversion factor method

Alternatively, use the conversion factor method shown in Example E.2. 

Unit ananysis has other names, including the factor-label method, the conversion factor method, and dimensional analysis. 

Many problems of chemistry can be readily solved by dimensional analysis using the factor-label or conversion-factor method. Dimensional analysis involves the use of proper units of dimensions for all factors that are multiplied, divided, added, or... 

The next two examples illustrate how the conversion-factor method may be used to convert one metric unit to another. 

The conversion-factor method can be used to convert any unit to another unit, provided a conversion equation exists between the two units. Relationships between certain U.S. units and metric units are given in Table 1.5. You can use these to convert between U.S. and metric units. Suppose you wish to convert 0.547 lb to grams. From Table 1.5, note that 1 lb = 0.4536 kg, or 1 lb = 453.6 g, so the conversion factor from pounds to grams is 453.6 g/1 lb. Therefore,... 

Now that you know how to find the mass of one mole of substance, there are two important questions to ask. First, how much does a given number of moles of a substance weigh Second, how many moles of a given formula unit does a given mass of substance contain Both questions are easily answered using dimensional analysis, or the conversion-factor method. ... 

This is the infamous Friedel-Crafts method and works in a manner similar to the previously mentioned method where P2P was made by merging benzene and chloroacetone using AICI3. This method is for speed makers only and is not recommended for conversion of 1,3-benzodioxole. However, this should work in a limited way on catechol. The conversion factor is very low but that isn t a major concern of speed chemists because cheap old benzene is the precursor and all of that benzene that isn t converted can be run back through this simple little process over and over again. Before she knows it, the chemist will have amassed an enormous amount of allylbenzene [139, 140]. 

Ash and Inorganic Constituents. Ash may be measured gravimetdcaHy by incineration in the presence of sulfudc acid or, more conveniendy, by conductivity measurement. The gravimetric result is called the sulfated ash. The older carbonate ash method is no longer in use. Ash content of sugar and sugar products is approximated by solution conductivity measurements using standardized procedures and conversion factors. 

Corrosion Rate by CBD Somewhat similarly to the Tafel extrapolation method, the corrosion rate is found by intersecting the extrapolation of the linear poi tion of the second cathodic curve with the equihbrium stable corrosion potential. The intersection corrosion current is converted to a corrosion rate (mils penetration per year [mpy], 0.001 in/y) by use of a conversion factor (based upon Faraday s law, the electrochemical equivalent of the metal, its valence and gram atomic weight). For 13 alloys, this conversion factor ranges from 0.42 for nickel to 0.67 for Hastelloy B or C. For a qmck determination, 0.5 is used for most Fe, Cr, Ni, Mo, and Co alloy studies. Generally, the accuracy of the corrosion rate calculation is dependent upon the degree of linearity of the second cathodic curve when it is less than... 

B is the potential of the reference electrode, without whose identification the potential U is undefined. Potentials are conveniently calculated against a standard reference value. Section 3.2 contains further details on reference electrodes and conversion factors. Section 3.3 describes practical methods for measuring potential in the case of flowing currents. 

For example, glutamic-oxalacetic transaminase activity can be standardized with oxalacetate but not with "convenient" substances such as pyruvate (J ). When reference serums are used, the label value should be confirmed at frequent intervals by the actual method being used routinely, as label values can be in error (19). Conversion factors to convert the results obtained by one method into those obtained by another can give erroneous results and should not be used. 

Protein content was determined by a semi-automated micro-Kjeldahl method [4], The conversion factor used was 6.25. 

Analytical methods for quantifying americium in environmental samples are summarized in Table 7-2. The methods that are commonly used in the analysis of americium based on activity are gross a analysis, a-spectrometry and gamma-ray spectrometry. MS detection techniques are used to measure the mass of americium in environmental samples. (The mass-activity conversion factor for 241Am is 0.29 (lCi/ lg or 3.43 ig/ p,Ci [Harvey etal. 1993]). 

Budget methods are based on the fact that there is a physiological upper limit to the amount of food and drink that can be consumed on any day. If the amount of additive present in that food is also limited (e.g. by national legislation) then there is an absolute maximum that can be ingested on any day. The assumptions in the budget method are extended to allow for the fact that only a proportion of the diet is likely to contain additives (Table 4.1).10 A conversion factor is produced which is used to derive the maximum use level from the ADI ... 

To use the proportion method to convert units, set up a proportion as described in Chapter 5. Keep the units consistent on both sides of the proportion. For example, if you want to convert 50.8 centimeters to inches, set up a proportion, such as meter = centimeter and substitute in tie given values on one side, tie conversion factor on tie other yyq = -yyy. Cross-multiply to get 2.54 xs=lx 50.8. Now, divide 50.8 by 2.54 to get n = 20 inches. 

The Saybolt universal viscosity equivalent to a given kinematic viscosity varies slightly with the temperature at which the determination is made because the temperature of the calibrated receiving flask used in the Saybolt method is not the same as that of the oil. Conversion factors are used to convert kinematic viscosity from 2 to 70 cSt at 38°C (100°F) and 99°C (210°F) to equivalent Saybolt universal viscosity in seconds. Appropriate multipliers are listed to convert kinematic viscosity over 70 cSt. For a kinematic viscosity determined at any other temperature, the equivalent Saybolt universal value is calculated by use of the Saybolt equivalent at 38°C (100°F) and a multiplier that varies with the temperature ... 

The unit analysis method involves analyzing the units and setting up conversion factors. You match and arrange the units so that they divide out to give the desired unit in the answer. Then you multiply and divide the numbers that correspond to the units. 

If an inhalation study in animals, list conversion factors used in determining human equivalent dose These conversion factors were taken from Interim Methods for Development of Inhalation Reference... 

Values of effectiveness factors in washcoat layers with non-uniform thickness around the channel perimeter have been studied by Hayes et al. (2005). However, the applicability of (even the generalized) effectiveness factor approach is quite limited in complex systems with competing reactions, surface deposition of reaction components, non-linear rate laws and under transient operating conditions (e.g. periodically operated NSRC). Typically, the effectiveness factor method can be used for more accurate prediction of CO, H2 and HC oxidation light-off and conversions in DOC. 

If none of this work was wasted, we could use it to lift a 1000-lb rock up to the top of Mount Everest (which is about 26,000 ft high). But in the 1840s, Robert Mayer did not know the conversion factor of heat equivalent to work of 740 ft-lb per Btu. It had not been determined yet, because Dr. Mayer was the one who first discovered it. So Dr. Mayer had to use the following method. 

The simplest way to carry out calculations that involve different units is to use the dimensional-analysis method. In this method, a quantity described in one unit is converted into an equivalent quantity with a different unit by using a conversion factor to express the relationship between units ... 

The dimensional-analysis method gives the right answer only if the equation is set up so that the unwanted units cancel. If the equation is set up in any other way, the units won t cancel properly, and you won t get the right answer. Thus, if you were to multiply your height in inches by the incorrect conversion factor inches per meter, you would end up with an incorrect answer expressed in meaningless units ... 

The known information is the speed in kilometers per hour the unknown is the speed in miles per hour. Find the appropriate conversion factor, and use the dimensional-analysis method to set up an equation so the km units cancel. 

To summarize, the classical method for analyzing sample rate conversion is to assume that the sample rate conversion factor is or can be approximated by a rational number. Then the sample rate conversion can be viewed as a three stage process, up-sample by an integer factor L, filter by h[n, and down-sample by M. Up-sampling by L inserts L — 1 zero valued samples in between the existing samples of x and decimating by M retains only each M-th sample. This approach is an analytical tool rather than an actual implementation strategy, and it allows the comparison of different sample rate conversion methods in a similar framework. 

The Saybolt universal viscosity (SUS) equivalent to a given kinematic viscosity varies slightly with the temperature at which the determination is made because the temperature of the calibrated receiving flask used in the Saybolt method is not the same as that of the oil. Conversion factors are used to convert... 

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