Big Chemical Encyclopedia

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

Articles Figures Tables About

Chemical source term definition

By definition of the reaction-progress variables, Y2 and T22 are zero for the inlet streams, and nonnegative inside the reactor due to the chemical source term. Once the CFD model has been solved, the reactant concentrations in each environment n are found from... [Pg.262]

Due to the conservation of elements, the rank of J will lie less than or equal to K — E 1 In general, rank(J) = Ny < K - E, which implies that V = K — T eigenvalues of J are null. Moreover, since M is a similarity transformation, (5.51) implies that the eigenvalues of J and those of J are identical. We can thus limit the definition of the chemical time scales to include only the Nr finite ra found from (5.50). The other N components of the transformed composition vector correspond to conserved scalars for which no chemical-source-term closure is required. The same comments would apply if the Nr non-zero singular values of J were used to define the chemical time scales. [Pg.171]

A transport equation for could be derived starting from its definition in (5.321). However, the resulting expression would be unduly complicated and not necessarily agree with our assumption of independence between Y and f.133 Instead, Y can be treated as any other scalar so that the transport equation for (Y ) has the form of (3.88) on p. 81 with (j a = T and a chemical source term given by... [Pg.236]

This symposium concerns models for predicting the fate of chemicals in the environment. Strictly speaking, the topic of this paper does not fall into the usual definition of fate models. However, every fate model has at least one source term. Although the source term for one fate model may be the output of another fate model (as when air transport models provide the deposition rates that are the inputs to an aquatic fate model), the chain always has to be traced to the original sources, whether they are natural or associated with human activities. [Pg.6]

The principle of stationary (or instationary) is also applied to the atmospheric budget of trace species, regarding F+ the source term (emission Q) and F the total removal term R (deposition and chemical conversion). With the definition of the residence time (see Chapter 4.5 for more details) it follows from Eq. (4.96) that ... [Pg.369]

Define any unusual terms use ISO definitions wherever possible. Quote sources. Chemical structures can be included here if relevant. [Pg.95]

Presented here is a glossary of terms related to the subject of this Concept Book. Several glossary entries are not used elsewhere in this publication. They have been included in case the user comes across an unfamiliar term in the course of managing chemical reactivity hazards. The Sources in the last column are all included in the reference list in the Reference section of this publication. Words in square brackets have been added to referenced definition. [Pg.148]

This appendix provides definitions and a source of basic information about polymers and chemical products - their properties, the processes by which they are made, the test methods used to assess product characteristics and assure product quality, and the types of equipment and materials that rely on feedstocks for their operation or manufacture. In most of the definitions, certain words and phrases are in italics others are in boldface. Italics indicate that the term is defined separately under its own heading boldface indicates that the term is of key importance in the definition or that it is a commonly used alternative word or phrase being described. [Pg.125]

The second contribution we present in two parts. In this first part we discuss definitions and terminology, mostly from recognized sources [2-9], Some ideas in this article go beyond established international understandings they are introduced for debate and possible refinement. The terms used here are responsive to the fundamental concepts under which chemical analysts can formally substantiate and record a traceability link. A chain of such links should lead from the value of a quantity in a sample up to a unit in the International... [Pg.12]

Previously the authors have brought into discussion principles for traceability in chemical analysis [1], In this Journal is also the first part of this contribution [2] on protocols for traceability of analytical-chemical measurements. This first part is intended mainly for specialists who develop such protocols. It deals with terminology and definitions used when describing protocols for traceability1. These terms are mostly taken from recognized literature sources [3-7], Analysts, who want to judge the applicability of an established protocol and to use it, will be familiar with most of these terms and find others self explanatory. They may, nev-... [Pg.24]

There are two main types of alumina (bauxite) ores used as the primary sources for aluminum metal and aluminum chemicals aluminum hydroxide [Al(OH)3] (gibbsite) and a mixed aluminum oxide hydroxide [AIO(OH)] (boehmite). Thus, bauxite is a term for a family of ores rather than a substance of one definite composition. An average composition of the ores used by industry today would be alumina (A1203), 35 to 60% silica (Si02), 1 to 15% ferric oxide (Fe203), 5 to 40% and titanium dioxide (Ti02), 1 to 4%. [Pg.42]

Paraffin followed by candelilla wax and microcrystalline waxes, and eventually by beeswax, are considered as the most effective moisture barriers derived from edible waxes (Morillon et al. 2002). There is no satisfactory chemical definition for the term wax which is used for a variety of products of mineral, botanical and animal origin that contain various kinds of fatty materials (Table 23.4). The term resins or lacs can also be used for plant or insect secretions that take place along resins ducts, often in response to injury or infection, and result in more acidic substances (Hernandez 1994). However, all waxes tend to contain wax esters as major components, that is, esters of long-chain fatty alcohols with long chain fatty acids. Depending on their source, they may additionally include hydrocarbons, sterol esters, aliphatic aldehydes, primary and secondary alcohols, diols, ketones, triacylglycerols, and so on. [Pg.555]


See other pages where Chemical source term definition is mentioned: [Pg.16]    [Pg.175]    [Pg.222]    [Pg.238]    [Pg.241]    [Pg.156]    [Pg.203]    [Pg.219]    [Pg.222]    [Pg.436]    [Pg.88]    [Pg.1]    [Pg.92]    [Pg.548]    [Pg.36]    [Pg.89]    [Pg.253]    [Pg.381]    [Pg.194]    [Pg.735]    [Pg.743]    [Pg.23]    [Pg.253]    [Pg.3]    [Pg.262]    [Pg.135]    [Pg.45]    [Pg.56]    [Pg.1008]    [Pg.76]    [Pg.7]    [Pg.536]   
See also in sourсe #XX -- [ Pg.18 , Pg.141 , Pg.142 ]

See also in sourсe #XX -- [ Pg.18 , Pg.141 , Pg.142 ]




SEARCH



Chemical source term

Chemical sources

Chemical terms

Chemical, definition

Source definition

Source term

Source term definition

Terms — definitions

© 2024 chempedia.info