Application factors

In some ways a security margin was being sought, because there was a lack of precise knowledge about the sensitivity of the aquatic organisms (Stephan et al., 1985). In addition, a more realistic prediction of the aquatic community concentration threshold was expected to be made. The system was easy and fast because it was based on a lethal concentration obtained from one or several species. 

Application factor values have been found to vary by a magnitude of 10 000 and sometimes even as great as 100000 for different compounds. Moreover, no relationship could be found between the acute lethality (LC50) of the compounds and the application factors. However, when the relationships between the application factors for a pair of species were examined, it was found that the application factor of one species could be predicted from that of another species (Kenaga, 1977). 

In spite of the fact that numerical values originally were established intuitively, they became more standardized as new investigations began to generate information on sublethality (Sprague, 1971). During the 1960s, the USA and Canada approved their use for substances of unknown non-effective concentration (NTAC, 1968 OWRC, 1970). 

Application factors are still used at the present time, although on a limited scale, particularly when enough knowledge is available regarding the sublethal effects of the toxic substances. For example, application factors of 0.01 and 0.05 have been established in Canada for persistent and non-persistent toxic substances, respectively (CCME, 1991). The potential health risks arising from using these application factors appear to be acceptable until clearer cause and effect dosages are available. 

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Carbon Equivalent (CE) is an approximate measure of weldability expressed in terms of the sum of carbon content and the alloy contents divided by applicable factors to relate equivalence in carbon in effectiveness in hardening—and thereby cracking. Commonly used formulas with commonly accepted but rather arbitrarily set maximums are ... 

C—The only applicable factor listed is the charge difference. The chloride ion is larger than the fluoride ion. The ion ratio is not important. 

Individual assessment of specific application factors indicate the key factors for selecting a specific polymer. 

The cost of ChemOx treatment depends on the specific application. Factors that influence cost include specific contaminants to be removed, concentration of contaminants in the effluent, amount or flow rate of water to be treated, discharge requirements, and geographical location. The vendor states that they will provide cost estimates for specific applications (D17705T, p. 4). 

The weighting factors, W, as introduced above, aim to be a pragmatic approach to harmonize prescription and reporting of radiation treatments. They are based on actual clinical practice, current techniques, and available radiobiological data. Their use should be limited to the technical treatment modality for which they were designed. They are not universally applicable factors, and they should not be multiplied or combined between each other. 

Because of the first of these uncertainties (the extrapolation across species), assessments of risks to human health apply an uncertainty or safety factor of 100 to the experimentally derived no observed adverse effect concentration (NOAEC), in other words the NOAEC is divided by 100 to derive a no-effect level for human toxicity. This factor has been used since 1961, when it was chosen on an essentially arbitrary basis (RCEP, 2003, p22). In the assessment of risks to the environment, application factors of 10, 50, 100 or 1000 are applied to the results of tests carried out on specific species,2 depending on the species used and whether the tests were long term or short term. Evidence to the Royal Commission on Environmental Pollution (RCEP) for their report Chemicals in products indicated that these are merely extrapolation factors — they express the statistical variability of test results but do not effectively take into account inter-species variability, the vulnerability of threatened species, lifetime exposures or the complexity of biological systems... 

In Table 8.4, add each applicable factor, then multiply by Fig. 8.1 base cost. You may interpolate between values shown. 

Figure 8.3 s cost curve is based on floating-head shell/tube exchanger construction with carbon steel shell and tubes. The cost figures may reasonably be extrapolated up to 10,000 ft2 of bare outside tube surface area. The subsequent tables, Tables 8.8 to 8.12, include factors for design type, materials of construction, and design pressures up to 1000 psi. Cost factors for foundations, field materials, field labor, and indirect cost may be obtained from these tables. Add each applicable factor, then multiply by Fig. 8.3 base cost. You may interpolate between values shown. 

Application factor Refers to number used to estimate concentration of a sub-stance/chemical that will not produce significant adverse effects/harm to a... 

Application factor Number used to estimate concentration of a substance or chemical that will not produce significant adverse effects to a population during chronic exposure. The factor is based on the formula application factor = maximum allowable toxicant concentration (MATC) (96 - h LC50)... 

Henderson, C. (1957) Application factors to be applied to bioassays for the safe disposal of toxic wastes. In Biological Problems in Water Pollution, pp. 31-37. US Department of Health, Education and Welfare, Public Health Service, Washington, DC. 

The definition of the acute to chronic ratio (ACR) has been one of the methods used to predict the threshold concentration at which a toxicant does not produce noticeable effects during a chronic exposure. This ratio is based on the same concept as the application factors, but its numerical value is the inverse (Stephan, 1982). The ACR is the ratio between chemical concentrations exerting a lethal versus sublethal toxic effect and describes the ratio of a lethal to sublethal end-point ... 

Application factor on a conservative scenario which means dividing the lowest toxicity values by a large safety factor so that the results will protect all species... 

Numerous flowmeters are often available for a specific application. Factors of importance in making a choice include the following ... 

An early freshwater quality criterion of 2.53 pmoles L 1 had been derived for HMX [72] by using a 0.05 application factor to the 96-h LC50 to 7-d old fry of fathead minnows (50.6 pmoles L ), which was the only freshwater organism that was sensitive to this chemical below its solubility limit. Talmage et al. [4], however, used data by Bentley et al. [72] and applied the formulas recommended by USEPA [80] to calculate SAV and SCV values, resulting in a fivefold higher SAV (Table 4.7). 

An application factor was used to derive an interim freshwater quality criterion for nitrocellulose (NC) [74], This chemical was not toxic to several species of fish, invertebrates, and algae, but had an EC50 of 554.3 pmoles I. to the freshwater alga P. subcap-itata. The value proposed for the protection of freshwater aquatic life was 47.9 pmoles I., approximately 10-fold below the lowest measured toxicity value. However, due to NC s lack of solubility in water, it is speculated if the phytotoxicity is due to adverse effects of the chemical per se or to obscuration of the test solution by the presence of excessive NC. No criteria have been proposed for the protection of marine life. 

In view of the variability of toxicity test results inherent in the multitude of experimental detail, the Committee decided to use application factors that express orders of magnitude of extrapolation - namely 1000, 100, and... 

Dense membrane reactors are discussed, emphasizing the most frequently investigated configurations and applications. Factors influencing economics are analyzed and, as a case study, results on the water-gas shift reaction in Pd-based membrane reactors are presented. 

The design of the pin and the clevis is dependent on the individual application. Factors, such as material compatibility and dynamic loading, must be considered. The design at the warm end is normally the most critical, since the strength of the materials has not been enhanced by a temperature reduction. 

Partial Valve Stroke Dangerous Coverage Product Type Application Factor ... 

Another important definition and terminology is the so-called application factor , which is applied for converting data from one exposure period or end point to another, e.g. from an acute EC50 (measured) to a chronic NOEC (predicted). For surfactants, application factors from 10 to 1000 are generally used when missing data for chronic toxicity have to be derived from acute toxicity tests. The stringency of the acute test influences the dimension of the application factor. 

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