Computerized evaluation

Short of resorting to computerized evaluation, the chemist or engineer may want to stay with more pedestrian long-hand numerical methods that are perfectly adequate for the immediate purpose of obtaining approximate orders and coefficients in power-law equations that serve only as temporary expedients. In essence, these methods are the numerical equivalents of the plots that were shown earlier in Table 3.1. Two detailed examples will illustrate typical work-up, including error recognition and relative reliability of experimental data. 

The series of photographs shown in Fig. 9.2 depicts various views of support laboratories. Here, particle size distributions and, sometimes, specific surface area, moisture content, powder flowability, product strength (defined, for example, by crushing, drop, or abrasion) and density or porosity and other, more specific information, such as dispersibility, solubility, reactivity, are determined [B.97]. The results define the feed characteristics and check the product properties. Often data acquisition and computerized evaluation systems are part of these supporting laboratory facilities. 

The gravimetric method is simple and yields reliable results. There are also fully automated measuring systems [14] provided with computerized evaluation possibilities [15]. 

Bauer, U. and Hatt, H. (1980) Demonstration of three different types of chemosensitive units in the crayfish claw using a computerized evaluation. Neurosci, Lett, 17, 209-14. 

Vassiliev PM, Breslaukhov AG, Kochetkov AN (1991) SOS, a system of computerized evaluation of environmental hazard of chemical compounds and production. In WATOC. Proceedings of the first All-Union conference on theoretical organic chemistry, Volgograd, 29 Sept-5 Oct 1991, p 507... 

Keywords— handwriting, ergonomics, movement analysis, computerized evaluation, writer s cramp. 

Physical testing appHcations and methods for fibrous materials are reviewed in the Hterature (101—103) and are generally appHcable to polyester fibers. Microscopic analyses by optical or scanning electron microscopy are useful for evaluating fiber parameters including size, shape, uniformity, and surface characteristics. Computerized image analysis is often used to quantify and evaluate these parameters for quaUty control. 

Computerized High Temperature Materials Properties Data-base Purdue University Purdue University (CINDAS) compiled from Hterature and evaluated reference data for high temperature materials... 

A piping system can be evaluated for its displacement and stress either by manual methods (charts, tables, hand calculation) or computerized solution. The latter has become the standard approach desktop and laptop computers can handle all but the most compHcated problems. Manual methods are used only for rough estimates on very simple systems. 

Systems for evaluating electrolytes for metal electrowinning have been developed and are being used commercially in zinc production (96). Computerized mathematical models of zinc electrowinning cells have been developed and vaUdated by comparison with experimental data taken from pilot-plant cells (97). 

The technician needs only 5 minutes per batch for evaluation, including graphics and tables because the computerized instrument and the integrator do the rest. 

Johnston RC, Worrall BB. Teleradiology assessment of computerized tomographs online reliability study (tractors) for acute stroke evaluation. Telemed J E Health 2003 9 227-233. 

Various aspects of in vitro gas production test have been reviewed by Getachew et al. [33], and these authors reported that gas measurement were centered on investigations of rumen microbial activities using manometric measurements and concluded that these methods do not have wide acceptability in routine feed evaluation since there was no provision for the mechanical stirring of the sample during incubation. Another in vitro automated pressure transducer method for gas production measurement was developed by Wilkins [34], and the method was validated by Blummel and Orskov [35] and Makkar et al. [36]. There are several other gas-measuring techniques such as (i) Flohenheim gas method or Menke s method [37] (ii) liquid displacement system [38] (iii) manometric method [39] (iv) pressure transducer systems manual [40], computerized [41], and combination of pressure transducer and gas release system [42]. 

Today, analytical evaluation is done on a large scale in a computerized way by means of data bases and expert systems (Sect. 8.3.6). In particular, a library search is a useful tool to identify pure compounds, confirm them and characterize constituents in mixtures. Additionally, unknown new substances may be classified by similarity analysis (Zupan [1986], Hippe [1991], Warr [1993], Hobert [1995]). The library search has its main application in such fields where a large number of components has to be related with large sets of data such as environmental and toxicological analysis (Scott [1995], Pellizarri et al. [1985]). 

Again, equation 66-A16 is cubic in Z4 and can be solved by algebraic methods. For higher powers of the variable we can derive similar expressions. After the sixth power, algebraic methods are no longer available to solve for the Z , but after evaluating the summations, computerized approximation methods can be used. 

There seems to be plenty of evaluation methods for inherent safety. Unfortunatelly they are not directly suitable safety analysis tools to be used with novel design systems in preliminary process design. Most existing safety analysis methods need detailed process information and are not directly applicable in early design stages. On the other hand all methods are not suitable for computerized use with optimization and simulation tools. 

The Inherent Safety Index, ISI, was developed to consider a wider range of factors affecting the inherent safety of the process (Ch. 8). The ISI allows the evaluation of inherent safety of process alternatives to be done in a computerized process synthesis environment. The represented synthesis approach allows the inherent safety comparison of process alternatives to be done flexibly and interactively in the conceptual design phase. 

If chemical-specific information is not available, the consequences may be able to be predicted by methods using compatibility groups, or chemicals with similar chemical structures that are expected to have similar chemical reactivity characteristics. One computerized tool that uses this approach is the Chemical Reactivity Worksheet made available by the U.S. National Oceanic and Atmospheric Administration (NOAA 2002). This program has over 6000 chemicals, mixtures, and solutions included in its database. It also predicts chemical reaction consequences of combining two materials at a time (e.g., "Heat generation by chemical reaction, may cause pressurization"). Examples from the Chemical Reactivity Worksheet are shown in Section 4.2. It is critical that all chemicals be positively identified to have a complete evaluation of all potential incompatibilities. 

This formidable equation should, in principle, be able to describe most phenomena with regard to their pressure and temperature behavior. However, its practical use may be limited due to its many parameters. Evaluation of the unknown parameters by means of computerized curve-fitting would require data from rather large pressure... 

Provided El spectra have been measured under some sort of standard conditions (70 eV, ion source at 150-250 °C, pressure in the order of 10 " Pa), they exhibit very good reproducibility. This is not only the case for repeated measurements on the same instrument, but also between mass spectrometers having different types of mass analyzers, and/or coming from different manufacturers. This property soon led to the collection of large El mass spectral libraries, either printed [76-78] or computerized. [79] The best established El mass spectral databases are the NIST/EPA/NIH Mass Spectral Database and the Wiley/NBS Mass Spectral Database, each of them giving access to about 120,000 evaluated spectra. [80-83]... 

The OECD Database on Chemical Risk Assessment Models includes information on models (computerized or capable of being computerized) that are used by OECD Member governments and industry to predict health or environmental effects (e.g., QSARs), exposure potential, and possible risks. The methods described have not been evaluated or validated by OECD. 

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