Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Process classification

The parallel stmcture in the NSC allows for rapid computations of output signals. Although training takes some time, it can be done once on a representative set of data. When training has been completed the classification process is fast and easy to implement in a realtime application. [Pg.112]

Classification Process simulation refers to the activity in which mathematical models of chemical processes and refineries are modeled with equations, usually on the computer. The usual distinction must be made between steady-state models and transient models, following the ideas presented in the introduction to this sec tion. In a chemical process, of course, the process is nearly always in a transient mode, at some level of precision, but when the time-dependent fluctuations are below some value, a steady-state model can be formulated. This subsection presents briefly the ideas behind steady-state process simulation (also called flowsheeting), which are embodied in commercial codes. The transient simulations are important for designing startup of plants and are especially useful for the operating of chemical plants. [Pg.508]

In this work the state-of-the-art and perspectives of column characterization and compai ison have been presented and discussed. All information about physico-chemical properties of RP HPLC Cl8 and C8 columns as porosity, average surface area, free silanol concentration, binding ligand density and others, were summarized. The points of views about column classifications, its advantages and disadvantages were discussed. It was shown that Cl8 and C8 HPLC column classification processes do not allow selecting the column with the same or preai range selectivity. [Pg.131]

Two-phase suspension systems produce beaded products with broader particle-size distribution (e.g., 1-50 /rm). The microspherical particles usually need to be classified repeatedly to reduce the particle-size distribution in order to improve the resolution and efficiency in the separation for use in chromatography. The actual classification process depends on the size range involved, the nature of the beaded product, and its intended applications. Relatively large (>50 /rm) and mechanically stable particles can be sieved easily in the dry state, whereas small particles are processed more conveniently in the wet state. For very fine particles (<20 /rm), classification is accomplished by wet sedimentation, countflow setting, countflow centrifugation, or air classification. [Pg.6]

Classification process - such as a tree diagram that shows how different things can be categorized from the most general to the most specific terms. [Pg.65]

However, if a taxon underlies extreme dissociative experiences it makes our classification process much easier because the existence of this taxon implies not only that there is a more severe form but also that there is a discrete form. The discreteness of this entity suggests there is a qualitative difference, perhaps with a different etiology, course, and treatment. These issues are unknown initially but form an important starting point for future work. [Pg.13]

The Metcalf Eddy HYDRO-SEP soil washing system is an ex situ, water-based technology that separates contaminants from soil matrices. The HYDRO-SEP modular system uses screening and hydraulic classification processes to separate uncontaminated soil particles from a contaminated mixture. [Pg.785]

Supervised (learning) methods where a priori information is needed, for example, demarcation of a certain number of classes in the classification process. [Pg.370]

Classification process of an analyte or a group of analytes from a certain sample according to physical size/solubility or chemical properties (bonding and reactivity)... [Pg.437]

Reliability of the classification process was the subject of a formal test in which the same set. of 80 actual reports from 1989 were independently classified by the local safety manager, and a student of EUT, This classification was on the basis of assigning one main cause only for each report (so called coarse" classification). The degree of overlap in the classification results of the two judges was regarded as a measure of the reliability of the classification process (see Table 8.1). [Pg.77]

The total efficiency has no value in determining the effectiveness of a classification process since it only defines how much of the feed ends up in one or other of the two outlet streams and not how much of the desired material ends up in the correct outlet stream. To discover this, it is necessary to determine the grade efficiency, which is independent of the feed provided the classifier is not overloaded. [Pg.252]

Evidence from appropriate studies in experimental animals can furnish much more detail, in the form of clinical observations, and macroscopic and microscopic pathological examination and this can often reveal hazards that may not be life-threatening but could indicate functional impairment. Consequently all available evidence, and relevance to human health, must be taken into consideration in the classification process. [Pg.189]

When a chemical is characterized only by use of animal data (typical of new chemicals, but also true for many existing chemicals), the classification process would include reference to dose/concentration guidance values as one of the elements that contribute to the weight of evidence approach. [Pg.191]

Where the mixture itself has not been tested to determine its aspiration toxicity, but there are sufficient data on the individual ingredients and similar tested mixtures to adequately characterize the hazard of the mixture, these data will be used in accordance with the following bridging principles. This ensures that the classification process uses the available data to the greatest extent possible in characterizing the hazards of the mixture without the necessity of additional testing in animals. [Pg.212]

While experimentally derived test data are preferred, where no experimental data are available, validated Quantitative Structure Activity Relationships (QSARs) for aquatic toxicity and log Kqw may be used in the classification process. Such validated QSARs may be used without modification to the agreed criteria, if restricted to chemicals for which their mode of action and applicability are well characterized. Reliable calculated toxicity and log Kow values should be valuable in the safety net context. QSARs for predicting ready biodegradation are not yet sufficiently accurate to predict rapid degradation. [Pg.226]


See other pages where Process classification is mentioned: [Pg.418]    [Pg.500]    [Pg.111]    [Pg.216]    [Pg.225]    [Pg.206]    [Pg.97]    [Pg.425]    [Pg.272]    [Pg.375]    [Pg.51]    [Pg.65]    [Pg.80]    [Pg.72]    [Pg.158]    [Pg.136]    [Pg.701]    [Pg.66]    [Pg.82]    [Pg.251]    [Pg.4]    [Pg.114]    [Pg.128]    [Pg.143]    [Pg.154]    [Pg.161]    [Pg.169]    [Pg.181]    [Pg.193]    [Pg.204]   
See also in sourсe #XX -- [ Pg.153 , Pg.154 , Pg.155 , Pg.156 , Pg.157 , Pg.158 , Pg.159 , Pg.160 , Pg.161 , Pg.162 , Pg.163 , Pg.164 , Pg.165 , Pg.166 , Pg.167 , Pg.168 , Pg.169 , Pg.170 , Pg.171 ]




SEARCH



Classification processing

© 2024 chempedia.info