Environmental variables, factors affecting

In the response surface strategy that was discussed in Section 2.3 standard response surface techniques are used to generate two response surface models, one for the mean response and one for the standard deviation of the response (or some function of the standard deviation). The standard deviation measures the stability of the response to the environmental variation. Standard analysis can reveal which factors affect the mean only, which only affect the variability, and which affect both the mean and the variability. The researcher can then apply optimization methods or construct contour plots of the mean and standard deviation response surfaces to determine settings of the design variables that will give a mean response that is close to the target with minimum variation. 

Many factors potentially can affect the distribution of an organic chemical between an aqueous and solid phase. These include environmental variables, such as temperature, ionic strength, dissolved organic matter concentration, and the presence of colloidal material, and surfactants and cosolvents. In addition, factors related specifically to the experimental determination of sorption coefficients, such as sorbent and solid concentrations, equilibration time, and phase separation technique, can also be important. A brief discussion of several of the more important factors affecting sorption coefficients follows. 

These two models illustrate how the properties of the compound influence the rate of evaporation from water under static conditions. Environmental conditions such as wind speed and turbulence in the water phase will have a marked influence on rates of evaporation that would reduce gradients and also reduce the width of the interfacial diffusion layers and systematic analysis of these effects have been discussed. Other variables will affect evaporation rates by controlling the actual concentration of the compound in solution. Suspended sediments and/or DOM would act in this manner. Weak acids and bases would only evaporate as the neutral species since the complementary anions or cations would be more water soluble and essentially have no vapor pressure. Consequently, environmental pH relative to pA values will be a consideration. It should be mentioned that compounds may distribute into the vapor phase by other processes than evaporation. Formation of aerosols, for example, can be a factor. 

The setup function in automated inspection corresponds to configuring the system for the task. Several environmental factors affect the setup function. In a machine vision system, lighting factors such as illumination levels, type of illumination, reflectivity, and contrast affect performance. Most vision systems are quite sensitive to these variables. In many cases, the automated system has failed because... 

Values of biomass specific rates are influenced by both genetic and environmental factors. The genes of a particular microorganism and the composition of the growth medium (including the presence of coenzymes, vitamins, hormones, mineral salts, and a variety of other soluble substrates) can affect the numerical values of the various -rates. Other environmental variables that may influence q -rates are temperature, pH, intensity and wavelength of incident radiation, and ionic strength. 

One variation of the Multiple Causation Theory is R. J. Firenzie s Theory of Accident Causation. Firenzie s theory is based on interaction among three components person, machine, and environment. Human variables of information, decisions, and perception of risks combine with machine hazards and environmental factors affecting the likelihood of an accident. 

The term sampling strategy , as used here, means the assembly of a series of decisions about how to make a set of measurements represent exposure for a particular purpose. An optimum strategy requires selection of the elements under the control of the exposure assessor that most efficiently achieve the objectives, given the physical circumstances and environmental variability (Health and Safety Executive 1989). An important factor in the design of any measurement scheme is the degree of variability in the system being observed. This variability affects both the number of samples to be taken and the accuracy of the results that can expected. Possible causes of variability typically observed include ... 

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