Assessment rapid

Medicinal chemists have, for many years, used QSARs as a tool for drug design. The EPA has used QSARs since 1981 to predict the aquatic toxicity of new, untested commercial chemical substances in the absence of test data. Chemists who are interested in designing safer chemicals will find QSARs very helpful, as they enable one to assess rapidly the toxicity of substances without having to synthesize and test the substances. 

Shen G. T. (1996) Rapid changes in the tropical ocean and the use of corals as monitoring systems. In Geoindicators Assessing Rapid Environmental Changes in Earth Systems (eds. A. Berger and W. lams). A. A. Balkema, Rotterdam, pp. 155-169. 

One of the earliest NDT applications for laser-based profilometry systems was for the inspection of marine boiler tubes. Under funding from the U.S. Navy", several systems were developed that were capable of rapidly and accurately mapping the inside surface of 25 mm and 50 mm diameter boiler tubing. Features such as internal pitting and corrosion can be located and quantitatively assessed using computer-graphic analysis. The system employs an... 

Metal deck assembhes are tested by UL for under-deck fire hazard by usiag their steiaer tunnel (ASTM E84). The assembly, exposed to an under-deck gas flame, must not allow rapid propagation of the fire down the length of the tuimel. FM uses a calorimeter fire-test chamber to evaluate the hazard of an under-deck fire. The deck is exposed to a gas flame and the rate of heat release is measured and correlated to the rate of flame propagation. A different FM test assesses the damage to roof iasulations exposed to radiant heat. 

Toxicology. Inorganic tin and its compounds are generally of a low order of toxicity, largely because of the poor absorption and rapid excretion from the tissues of the metal (42—49). The acidity and alkalinity of their solutions make assessment of their parenteral toxicity difficult. The oral LD q values for selected inorganic tin compounds are Hsted in Table 2. It is estimated that the average U.S. daily intake of tin, which is mostly from processed foods, is 4 mg (see Food processing). 

In the 3M Water/Alcohol Drop Test (41), this test is designed to provide a simple, rapid method to assess the aqueous stain resistance of substrates treated with a protective finish. 

Contribution Analysis Contribution analysis can be used to make rapid assessments of the effect of changes in manufacturing costs on profitability. A dimensionless contribution efficiency T can be defined by rewriting Eq. (9-12) in the form... 

Runaway Reactions Runaway temperature and pressure in process vessels can occur as a resiilt of many fac tors, including loss of cooling, feed or quench failure, excessive feed rates or temperatures, contaminants, catalyst problems, and agitation failure. Of major concern is the high rate of energy release and/or formation of gaseous produc ts, whiai may cause a rapid pressure rise in the equipment. In order to properly assess these effec ts, the reaction kinetics must either be known or obtained experimentally. 

This is an average value of metal erosion during the length of service and may vary with soil conditions. In coastal areas, for instance, where the subsoil water is saline, erosion of metal would be much more rapid and a further safety factor must be considered. Field experience will be a better guide to assess this. 

In most circumstances, it can be assumed diat die gas-solid reaction proceeds more rapidly diaii die gaseous transport, and dierefore diat local equilibrium exists between die solid and gaseous components at die source and sink. This implies diat die extent and direction of die transport reaction at each end of die temperature gradient may be assessed solely from diermodynamic data, and diat die rate of uansport across die interface between die gas and die solid phases, at bodi reactant and product sites, is not rate-determining. Transport of die gaseous species between die source of atoms and die sink where deposition takes place is die rate-determining process. 

Similarly, contaminant concentrations in rivers or streams can be roughly assessed based on rate of contaminant introduction and dilution volumes. Estuary or impoundment concentration regimes are highly dependent on the transport mechanisms enumerated. Contaminants may be localized and remain concentrated or may disperse rapidly and become diluted to insignificant levels. The conservative approach is to conduct a more in-depth assessment and use model results or survey data as a basis for determining contaminant concentration levels. 

A useftil applicadon of time-dependent PL is the assessment of the quality of thin III-V semiconductor alloy layers and interfaces, such as those used in the fabri-cadon of diode lasers. For example, at room temperature, a diode laser made with high-quality materials may show a slow decay of the acdve region PL over several ns, whereas in low-quality materials nonradiative centers (e.g., oxygen) at die cladding interface can rapidly deplete the free-carder population, resulting in much shorter decay times. Measurements of lifetime are significandy less dependent on external condidons than is the PL intensity. 

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