Numerical standards

The quantitative measurement of pigment or pigmented system deterioration upon exposure to heat or light used to be expressed by visual numerical standards. In modem times color differences are expressed in the CIELAB system which has become the leading method for color characterization (8). 

As microwave sample preparation has evolved, standard microwave procedures have been developed and approved by numerous standard methods organisations (ASTM, AOAC International, EPA, etc.), see ref. [64]. Examples are standard test methods for carbon black/ash content (ASTM Method D 1506-97), lead analysis in direct paint samples (ASTM Method E 1645-94), etc. Table 8.15 shows some microwave ashing references (detection weight). A French AFNOR method utilises the atmospheric pressure single-mode microwave method as an alternative sample preparation procedure for Kjeldahl nitrogen determination [84], The performance of a microwave-assisted decomposition for rapid determination of glass fibre content in plastics for QC has been described [85]. 

For around 20 years now, numerous standards and recommendations have been drawn up at national and international level and revised, whenever necessary, in accordance with the state of the art. These standards and recommendations must be observed whenever use is made of vacuum equipment (pumps, gauges, valves, etc.) and vacuum apparatus, systems and plants are assembled. They not only contain specifications applying specially to vacuum technology, but also go beyond this specific field and involve, for example, physical units, formulas, noise protection regulations, etc. 

A prerequisite for any quality control is the definition of how the characteristics of a specific raw material, an intermediate product or a final product of a manufacturing process should be described. This means that all characteristics for every single product have to be defined in adequate standards and specifications so that the results obtained can be compared with these data. Numerous standards and specifications have been established in more or less official specification collections, for example pharmacopoeias, the aforementioned ISO or DIN standards, standards of the Essential Oil Association or the American Spice Trade Organization (ASTA). 

In essence, the approach to protecting public health and the environment under AEA has been based on numerical standards that specify acceptable overall performance of a radioactive waste management or disposal system. The standards for acceptable system performance are in the form of limits on radiation dose to members of the public or other related criteria. Radioactive waste generators and radioactive waste management and disposal facilities are afforded considerable flexibility in meeting these standards, and there are few prescriptive technical requirements that apply to all facilities. 

In each of these soil field duplicate collection techniques, matrix variability is a decisive factor that cannot be entirely controlled. Consequently, field duplicate RPD cannot be controlled and it should not be compared to a numeric standard, such as an acceptance criterion. Soil field duplicates are best assessed qualitatively by drawing conclusions from the comparison of the identified contaminants and their concentrations. 

The thermodynamic analysis of a system of stoichiometric equations is directed to the calculation of reaction enthalpies whose knowledge is necessary for energy balances and to the determination of equilibrium constants in order to evaluate the limitations of the yield and selectivity enforced by thermodynamic laws. There are numerous standard or advanced textbooks dealing with these questions, as well as many authoritative reviews of thermochemical data. Thus, only two points will be mentioned here. 

Numerous standard test methods have been developed by various government, industrial, and university investigators. Many of these have been prepared or adopted under the auspices of the ASTM Committee D 14 on Adhesives or other professional societies. Reference to the appropriate standards will adequately equip one with the background necessary to conduct the test or a version of it. Several of the more common standard tests are described in this section. Numerous variations exist for specific applications or materials. In these descriptions, the emphasis is on understanding of the reasons for the test, its relationship to a specific adhesive property, advantages and limitations of the test, and possible variations or extrapolations of the test method. The detailed description of the test mechanics is kept to a minimum, since they are adequately covered in the existing standards and specifications. 

Numerical standards may be further expressed in different ways (e.g., as percentiles, averages, or absolute maxima). These different expressions of a standard are dealt with in more detail in this chapter. 

An important principle that underpins the use of the 5-point ideal standard is that checking compliance with numerical standards is a statistical process. This requires that a standard is defined in terms that allow the use of statistical methods, typically... 

It is appropriate to have different types of environmental quality standards (EQSs, often referred to as soil quality standards [SQSs] for soils) to protect the environment and human health, but there are many more ways to set and implement a standard than legally binding limits that are introduced through direct regulation. However, even the softer approaches entail the use of a numerical standard that must have a sound basis in science. 

As shown in Equation (19), it is conventional for Nernst equations to represent the sum of E° and the logarithmic term, rather than the difference. Consequently, in the activity quotient, the activity of the oxidized form of the electroactive species has to be written as the numerator. Standard potentials of individual electrode reactions are conveniently available in textbooks of physical chemistry and electrochemistry, and in relevant handbooks. A small selection is presented in Table 3.1.3. 

Widiyanto, A., Kato, S., Maruyama, N., and Kojima, Y., Environmental impact of fossil fuel fired co-generation plants using a numerically standardized LCA scheme, J. Energy Resource Technol., 125, 9-16, 2003. 

D. C. Rich and J. M. Jalijali, Numerical Standards Are the Materials Ready , paper presented at the AIC Silver Jubilee Meeting, Princeton, NJ, June 23-24,1992. 

General enz.ymology is discussed effectively in numerous standard treatises, and one of the must concise discussions appears in the classic work by Ferdinand, who includes reviews of enzyme structure and function, biuenergetics. and kinetics and appropriate illustrations with a total of 37 enzymes. selected from the six major classc.s. For additional basic Studies of enzymolugy. the reader should refer to this cla.ssic monograph and to a coniprehcn.sive review of this topic. ... 

Numerous standard or certified reference materials exist for verifying the reliability of new or modified methods, especially for total mercury standard reference materials for individual organomercury species can be more difficult to obtain. The existing methods for determining mercury in biological and environmental matrices are described more fully in the following sections. 

Whenever information must be shared between two different information systems, a common method of identifying entities must also be shared. The broader the necessity for sharing, the more universal the identifiers have to be. For this reason, numerous standards have been developed to help identify and share information about healthcare information entities such as laboratory tests, images, diagnoses, and procedures. 

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