Effect of Variables

Effect of Variables on Mean Droplet Size. Some of the principal variables affecting the mean droplet diameters for pressure swid atomizers may be expressed by equation 14. 

Semiconducting Ceramics. Most oxide semiconductors are either doped to create extrinsic defects or annealed under conditions in which they become non stoichiometric. Although the resulting defects have been carefully studied in many oxides, the precise nature of the conduction is not well understood. Mobihty values associated with the various charge transport mechanisms are often low and difficult to measure. In consequence, reported conductivities are often at variance because the effects of variable impurities and past thermal history may overwhelm the dopant effects. 

The volumetric coefficient h a from the combination of Eqs. (14-178) and (14-179) is useful in defining the effect of variable changes but is limited in value because of its dependence on D. The prodiicl of area and coefficient obtained from a given mass of hqiiid is proportional to (1/D ) for small diameters. The prime problem is that droplet-size estimating procedures are often no better than 50 percent. A secondary problem is that there is no that truly characterizes either the motion or transfer process for the whole spectrum of particle sizes present. See Eqs. (14-193) and (14-194). 

Effect of Variables on Corrosion Tests It is advisable to apply a factor of safety to the results obtained, the factor varying with the degree of confidence in the applicabihty of the results. Ordinarily, a factor of from 3 to 10 might be considered normal. 

Effects of variable supply parameters on the performance of an induction motor... 

Improperly set tolerances and uncontrolled variation are one of the greatest causes of defects, scrap, rework, warranty returns, increased product development cycle time, work flow disruption and the need for inspection (Gerth and Hancock, 1995). If manufacturing processes did not exhibit variation, quality problems would not arise, therefore reducing the effects of variability at the design stage, in a cost-effective way, improves product quality (Bergman, 1992 Kehoe, 1996). 

Robust design improves product quality by reducing the effects of variability (Phadke, 1989). 

Hsu [124] presents equations for directly calculating random packings based on published data and which are adaptable for computer programming and thereby studying the effects of variables. The basic data are essentially a match with Figure 9-21D. 

Discussion. The turbidity of a dilute barium sulphate suspension is difficult to reproduce it is therefore essential to adhere rigidly to the experimental procedure detailed below. The velocity of the precipitation, as well as the concentration of the reactants, must be controlled by adding (after all the other components are present) pure solid barium chloride of definite grain size. The rate of solution of the barium chloride controls the velocity of the reaction. Sodium chloride and hydrochloric acid are added before the precipitation in order to inhibit the growth of microcrystals of barium sulphate the optimum pH is maintained and minimises the effect of variable amounts of other electrolytes present in the sample upon the size of the suspended barium sulphate particles. A glycerol-ethanol solution helps to stabilise the turbidity. The reaction vessel is shaken gently in order to obtain a uniform particle size each vessel should be shaken at the same rate and the same number of times. The unknown must be treated exactly like the standard solution. The interval between the time of precipitation and measurement must be kept constant. 

Supporting electrolytes are required in controlled-potential experiments to decrease the resistance of the solution, to eliminate electromigration effects, and to maintain a constant ionic strength (i.e., swamping out the effect of variable... 

A series of simulations were performed to study the effect of variables such as initiator concentration, initiator half-life and activation energy on the optimum temperature and optimum time. It was assumed that initially the polymerization mixture contained S volume percent monomer, the rest of the mixture being solvent and polymer formed earlier. It was required to reduce the monomer concentration from S volume percent to 0.S volume percent in the minimum possible time. The kinetic and tbeimodyamnic parameters used are similar to those of free radical polymerization of MMA. The parameter values are given in Appendix B. 

A two level full factorial experimental design with three variables, F/P molar ratio, OH/P wt %, and reaction temperature was implemented to analyses the effect of variables on the synthesis reaction of PF resol resin. Based on the composition of 16 components of 10 samples, the effect of three independent variables on the chemical structure was anal3 ed by using 3 way ANOVA of SPSS. The present study provides that experimental design is a very valuable and capable tool for evaluating multiple variables in resin production. 

Stewart, J. E., Spectral-bandwidth effects of variable-wavelength absorption detectors in liquid chromatography, ]. Chromatogr., 174, 283, 1979. 

The diffusivities thus obtained are necessarily effective diffusivities since (1) they reflect a migration contribution that is not always negligible and (2) they contain the effect of variable properties in the diffusion layer that are neglected in the well-known solutions to constant-property equations. It has been shown, however, that the limiting current at a rotating disk in the laminar range is still proportional to the square root of the rotation rate if the variation of physical properties in the diffusion layer is accounted for (D3e, H8). Similar invariant relationships hold for the laminar diffusion layer at a flat plate in forced convection (D4), in which case the mass-transfer rate is proportional to the square root of velocity, and in free convection at a vertical plate (Dl), where it is proportional to the three-fourths power of plate height. 

With these provisos, conclusions were derived from the results of this first experimental design. There was no difference in the effects of Variable II vs. Ill for any of the properties measured. Because Variable II was judged easier to work with in the lab and more stable than Variable III, Variable II was chosen as the polar monomer in future work. Both the Property C and Property D targets appeared easily attainable. As had been foreseen, Property A was mutually exclusive of both Properties B and E. However, note that adequate models were not obtained for Properties C, D, or E, so conclusions based on these models in Table IV are questionable. 

The effect of variable density can be accounted for by an expansion factor Y as has been done for flow in pipes and meters, in which case Eq. (10-44) can be written... 

Effect of variables such as charging rates, catalyst addition, and possible contaminants. 

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