Ratio-proportion method

There are two methods used to calculate the dose to administer to the patient. These are the formula method and the ratio-proportion method. Both methods produce the same results. 

The ratio-proportion method applies the ratio of the on-hand medication to the medication order to calculate the correct dose. Here are the components of the ratio-proportion formula. The ratio of the left side of the equation equals the ratio on the right side of the equation. The left side of the equation is the ratio of the medication on hand. The right side of the equation is the medication ordered by the healthcare provider. X is the quantity of the medication that will be administered to the patient. 

Parenteral medication is a medication that is administered to a patient by an injection or by an intravenous flow. The dose for an injection is calculated using the formula method or the ratio-proportion method that is described previously in this chapter. 

Heparin is a medication that inhibits the formation of platelets and can be administered either as a subcutaneous injection or as a continuous intravenous infusion. The proper dose of heparin is always calculated using either the formula method or the ratio-proportion method. 

The formula method and the ratio-proportion method are also used to calculate parenteral medications. Alternatively, parenteral medication can be administered through a vein either as a bolus or an infusion. If infusing through an intravenous Mne, the nurse must calculate the number of drops per minute the IV should run to dehver the amount of medication ordered. 

At best, signal averaging yields an improvement of the signal-to-noise ratio proportional to VlV, where N is the number of signals averaged. Consequently, the method is rather inefficient and time-consuming, except when the entire curve can be obtained in a very short time, as with fluorescence transients following a short laser pulse. 

The error-in-variables method was used to estimate the reactivity ratios. This method was developed by Reilly et al. (57, 58), and it was first applied for the determination of reactivity ratios by O Driscoll, Reilly, and co-workers (59, 60). In this work, a modified version by MacGregor and Sutton (61) adapted by Gloor (62) for a continuous stirred tank reactor was used. The error-in-variables method shows two important advantages compared to the other common methods for the determination of copolymer reactivity ratios, which are statistically incorrect, as for example, Fineman-Ross (63) or Kelen-Tiidos (64). First, it accounts for the errors in both dependent and independent variables the other estimation methods assume the measured values of monomer concentration and copolymer composition have no variance. Second, it computes the joint confidence region for the reactivity ratios, the area of which is proportional to the total estimation error. 

Dosing Adjustment Based on Drug Ceearance (Ratio or proportion method)... 

Liquid-liquid extraction (LLE) is based on a simple principle that a compound will be partitioned between two immiscible solvents with concentration at a distribution ratio proportional to its solubility in each of the solvents. LLE is a common method of working up organic reaction mixtures. A conventional LLE application is to separate compounds between water and an organic solvent such as diethyl ether, ethyl acetate, or methylene chloride. Acidic or basic buffers are often used to control the distribution ratio of a certain substance. 

Porter and Momoh have suggested an approximate but simple method of calculating the total vapor rate for a sequence of simple columns. Start by rewriting Eq. (5.3) with the reflux ratio R defined as a proportion relative to the minimum reflux ratio iimin (typically R/ min = 1-D- Defining Rp to be the ratio Eq. (5.3) becomes... 

The existence of this situation (for nonporous solids) explains why the ratio test discussed above and exemplified by the data in Table XVII-3 works so well. Essentially, any isotherm fitting data in the multilayer region must contain a parameter that will be found to be proportional to surface area. In fact, this observation explains the success of Ae point B method (as in Fig. XVII-7) and other single-point methods, since for any P/P value in the characteristic isotherm region, the measured n is related to the surface area of the solid by a proportionality constant that is independent of the nature of the solid. 

This contrasts with a limiting ratio of 2 for the case of termination by disproportionation. Since and can be measured, this difference is potentially a method for determining the mode of termination in a polymer system. In most instances, however, termination occurs by some proportion of both modes. Although general expressions exist for the various averages and their ratio when both modes of termination are operative, molecular weight data are generally not sufficiently precise to allow the proportions of termination modes to be determined in this way. 

The copolymer composition equation relates the r s to either the ratio [Eq. (7.15)] or the mole fraction [Eq. (7.18)] of the monomers in the feedstock and repeat units in the copolymer. To use this equation to evaluate rj and V2, the composition of a copolymer resulting from a feedstock of known composition must be measured. The composition of the feedstock itself must be known also, but we assume this poses no problems. The copolymer specimen must be obtained by proper sampling procedures, and purified of extraneous materials. Remember that monomers, initiators, and possibly solvents are involved in these reactions also, even though we have been focusing attention on the copolymer alone. The proportions of the two kinds of repeat unit in the copolymer is then determined by either chemical or physical methods. Elemental analysis has been the chemical method most widely used, although analysis for functional groups is also employed. 

Thermal conductivity is used as an analytical tool in the deterrnination of hydrogen. Because the thermal conductivities of ortho- and i7n -hydrogen are different, thermal conductivity detectors are used to determine the ortho para ratio of a hydrogen sample (240,241). In one method (242), an analy2er is described which spHts a hydrogen sample of unknown ortho para ratio into two separate streams, one of which is converted to normal hydrogen with a catalyst. The measured difference in thermal conductivity between the two streams is proportional to the ortho para ratio of the sample. 

Processing. Tungsten carbide is made by heating a mixture of lampblack with tungsten powder in such proportions that a compound with a combined carbon of 6.25 wt % is obtained. The ratio of free-to-combined carbon is of extreme importance. Tantalum and titanium carbides are made by heating a mixture of carbon with the metal oxide. Multicarbide powders, such as M02C—WC, TaC—NbC, and TiC—TaC—WC, are made by a variety of methods, the most important of which is carburization of powder mixtures. 

The pressure drop for gas—Hquid flow is deterrnined by the Lockhart-MartineUi method. It is assumed that the AP for two-phase flow is proportional to that of the single phase times a function of the single-phase pressure drop ratio P. 

It is often experimentally convenient to use an analytical method that provides an instrumental signal that is proportional to concentration, rather than providing an absolute concentration, and such methods readily yield the ratio clc°. Solution absorbance, fluorescence intensity, and conductance are examples of this type of instrument response. The requirements are that the reactants and products both give a signal that is directly proportional to their concentrations and that there be an experimentally usable change in the observed property as the reactants are transformed into the products. We take absorption spectroscopy as an example, so that Beer s law is the functional relationship between absorbance and concentration. Let A be the reactant and Z the product. We then require that Ea ez, where e signifies a molar absorptivity. As initial conditions (t = 0) we set Ca = ca and cz = 0. The mass balance relationship Eq. (2-47) relates Ca and cz, where c is the product concentration at infinity time, that is, when the reaction is essentially complete. 

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