Factors affecting laboratory

Factors affecting laboratory polymerisation of the monomer have been discussed" and these indicate that a Ziegler-Natta catalyst system of violet TiCl3 and diethyl aluminium chloride should be used to react the monomer in a hydrocarbon diluent at atmospheric pressure and at 30-60°C. One of the aims is to get a relatively coarse slurry from which may be washed foreign material such as catalyst residues, using for example methyl alcohol. For commercial materials these washed polymers are then dried and compounded with an antioxidant and if required other additives such as pigments. 

A7. Anonymous, Drugs and other factors affecting laboratory tests. Med. Lett. 13, 81-84 (1971). 

Irjala KM, Gronroos PE. Preanalytical and analytical factors affecting laboratory results. Ann Med 1998 30 267-72. 

Factors affecting laboratory testing include the following ... 

Adsorption — An important physico-chemical phenomenon used in treatment of hazardous wastes or in predicting the behavior of hazardous materials in natural systems is adsorption. Adsorption is the concentration or accumulation of substances at a surface or interface between media. Hazardous materials are often removed from water or air by adsorption onto activated carbon. Adsorption of organic hazardous materials onto soils or sediments is an important factor affecting their mobility in the environment. Adsorption may be predicted by use of a number of equations most commonly relating the concentration of a chemical at the surface or interface to the concentration in air or in solution, at equilibrium. These equations may be solved graphically using laboratory data to plot "isotherms." The most common application of adsorption is for the removal of organic compounds from water by activated carbon. 

Professional society promotes the study and control of environmental factors affecting the health and well-being of factory workers, including procedures for monitoring the exposure to toxic materials in the work place. Offers laboratory accreditation and testing programs and informational pamphlets on various health and safety topics. 

Theoretical Analysis of Resonance Tube , The Singer Company, Final Report KD 72-82 (1972) 58) F.J. Valenta, The State of the Art of Navy Pyrotechnic Delays , Expls Pyrots (The Franklin Institute Research Laboratories) 5, Nos 11 12 (Nov-Dec 1972). See also Ref 144, pp 185—95. See also Some Factors Affecting Burning Rates and Variability of Tungsten and Manganese Delay Compositions , Ref 144, pp 157—83. See also Mil Spec for Tungsten Delay Compositions , MIL-T-23132A (June 1972) 59) C.F. Parrish et al, Radiation... 

The rate of product to be applied is the critical factor affecting all residue studies. The rate should be the highest recommended rate for that particular crop and should be applied at the limit of the GAP for the specific crop. The test item should ideally be pre-weighed in a laboratory prior to making the application. In most cases, this procedure results in easier accountability of test items, more accurate measurement of required doses, and more accurate application in the field since only the correct amount of water is required to be added by the field operator. This procedure also reduces the quantity of test item required and hence reduces the waste, which has to be disposed of. An additional spare sample, which is weighed at the same time in case of mishap with the original sample may be prepared. 

A third factor affecting the quantity to be processed is the scale of the processing operation. A laboratory-scale operation will typically require less sample than a pilot-scale operation and much less than a commercial scale operation. Throughout the process, each unit operation must be supplied sufficient material to operate the process adequately while providing representative samples from the process. 

K. Bourke and H. Davies, Factors affecting service life predictions of buildings a discussion paper, BRE Laboratory Report BR 320, Building Research Laboratory, Watford, UK, 1997. 

Vesell ES, Lang CM, White WJ, et al. 1976. Environmental and genetic factors affecting the response of laboratory animals to dmgs. Fed Proc 35 1125-1132. 

Gore AY, McFarland DW, Batuyios NH. Fluid-bed granulation factors affecting the process in laboratory development and production scale-up. Pharm Technol 1985 9(9) 114. 

Although early studies in the marine environment showed little diel variability in the surface-water H202 concentration (22, 23), initial observations of rather high concentrations of H202 in surface waters of lakes led us to examine the factors affecting its variability and distribution. This chapter provides a critical review of the literature on H202 formation and decay, integrated with recent results of both field and laboratory studies. 

These comments on factors affecting test results may seem extremely obvious but it is a simple fact that failure to pay sufficient attention to them is the main cause of the poor reproducibility that has been found when comparisons between laboratories have been made, and the reason for most disputes over test results. 

To preface the presentation of factors affecting kinetics measurements by time-resolved mass spectrometry in the next section, it is useful to see how a typical experimental setup would be configured. The following is a description of the apparatus originally designed and built in the author s laboratory at the University of Minnesota by S. B. Moore [35], and subsequently modified and improved, primarily by Fuxiang Wu. 

Another factor affecting the choice of filler is its ability to be thoroughly cleaned. The simpler the valve the easier it will be to clean, and the more small passages, springs or complicated seal arrangements there are the more difficult cleaning will be. Most filler manufacturers will test fill and test clean products in their laboratories to demonstrate the cleanability and filling performance to be expected from their machinery. 

Social and husbandry factors affecting the prevalence and severity of barbering ( whisker-trimming ) by laboratory mice. Appl Anim Lab Sci 89, 263-282. 

Over the past four years we have developed a laboratory method for measuring gas uptake in a way that allows control of the factors affecting gas uptake. Utilizing this method, we have measured mass accommodation coefficients and have studied the effects of the various processes on gas uptake. 

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