Big Chemical Encyclopedia

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

Articles Figures Tables About

Dimensions Definition

A model is fully constrained where modeling procedures generate all shape and dimension definitions as constraints. This shape is considered to be a result of a design and it cannot be modified. A model that contains shapes and dimensions free for modification is under-constrained. In many cases, under-constraining is allowed. [Pg.110]

A dimension definition represents the intent of the engineer who made the related decision. Its content is handled as a... [Pg.173]

Modification of a dimension normally requires modification of other dimensions. They may be calculated using formulas, rules, and associativities in the model. Allowed ranges, formulas, rules, and associativities in a dimension definition prepare decisions for the modification of dimension values at subsequent construction and downstream applications of the model. [Pg.174]

Once the overall chamber volume is estimated, the main discussion is related to the 3 dimensions definition. Several parameters should be taken into account at this stage. The available space is obviousiy one of them, particularly when repairing an existing furnace in a given plant. In the case of end-port furnaces, one constraint is also the width of the furnace itself, it is not recommended to have chambers iarger than the furnace. On top of a complex layout, one problem in that case would be the homogeneity of the exhaust fumes repartition, this chamber s extra-width would certainly lead to a dead zone with a iimited amount of preheating. [Pg.145]

Work planning deals with detailing of the blank (type of blank and its dimensions), definition of process sequencing, choice of production resources (machines and tools), and calculation of specified times for the process steps. Assembly planning... [Pg.244]

Figurel. The sketch of micro-feature dimension definition... Figurel. The sketch of micro-feature dimension definition...
Finally, each coefficient were standardized by the division of the sum of all coefficients(2). This definition allows also to regard as the co-occurrence matrix as a function of probability distribution, it can be represented by an image of KxK dimensions. [Pg.232]

Adsorbents such as some silica gels and types of carbons and zeolites have pores of the order of molecular dimensions, that is, from several up to 10-15 A in diameter. Adsorption in such pores is not readily treated as a capillary condensation phenomenon—in fact, there is typically no hysteresis loop. What happens physically is that as multilayer adsorption develops, the pore becomes filled by a meeting of the adsorbed films from opposing walls. Pores showing this type of adsorption behavior have come to be called micropores—a conventional definition is that micropore diameters are of width not exceeding 20 A (larger pores are called mesopores), see Ref. 221a. [Pg.669]

For tire purjDoses of tliis review, a nanocrystal is defined as a crystalline solid, witli feature sizes less tlian 50 nm, recovered as a purified powder from a chemical syntliesis and subsequently dissolved as isolated particles in an appropriate solvent. In many ways, tliis definition shares many features witli tliat of colloids , defined broadly as a particle tliat has some linear dimension between 1 and 1000 nm [1] tire study of nanocrystals may be drought of as a new kind of colloid science [2]. Much of die early work on colloidal metal and semiconductor particles stemmed from die photophysics and applications to electrochemistry. (See, for example, die excellent review by Henglein [3].) However, the definition of a colloid does not include any specification of die internal stmcture of die particle. Therein lies die cmcial distinction in nanocrystals, die interior crystalline stmcture is of overwhelming importance. Nanocrystals must tmly be little solids (figure C2.17.1), widi internal stmctures equivalent (or nearly equivalent) to drat of bulk materials. This is a necessary condition if size-dependent studies of nanometre-sized objects are to offer any insight into die behaviour of bulk solids. [Pg.2899]

In these definitions the suffix zero refers to conditions at the surface of the pellet and a is a characteristic dimension, for example the radius in Che case of a spherical pellet. In terms of these variables equations (12.29)-(12.31) take the following form... [Pg.169]

Anuther concept that is extremely powerful when considering lattice structures is the fi i i/imca/ lattice. X-ray crystallographers use a reciprocal lattice defined by three vectors a, b and c in which a is perpendicular to b and c and is scaled so that the scalar juoduct of a and a equals 1. b and c are similarly defined. In three dimensions this leads to the following definitions ... [Pg.159]

To be eonformable to multiplieation, the horizontal dimension of A must be the same as the vertieal dimension of B, that is, n = mg. Square matr ices of the same size are always eonformable to multiplieation. This unusual definition of multiplieation, with its rorles for dimensions, will beeome elear with repeated use. The matriees we shall be interested in will usually be square you should assume that the matriees diseussed below are square unless otherwise stipulated. The rules for reetangular matriees and eolumn and row matriees will be developed as needed. [Pg.33]

Chemistry in three dimensions is known as stereochemistry At its most fundamental level stereochemistry deals with molecular structure at another level it is concerned with chemical reactivity Table 7 2 summarizes some basic definitions relating to molec ular structure and stereochemistry... [Pg.315]

What is especially significant about Eq. (9.68) is the observation that the coil expansion factor a definitely increases with M for good solvents, meaning that-all other things being equal longer polymer chains expand above their 0 dimensions more than shorter chains. Even though the dependence of a on... [Pg.620]

The constant is not a tme partition coefficient because of difference, — V, includes the soflds and the fluid associated with the gel or stationary phase. By definition, IV represents only the fluid inside the stationary-phase particles and does not include the volume occupied by the soflds which make up the gel. Thus is a property of the gel, and like it defines solute behavior independently of the bed dimensions. The ratio of to should be a constant for a given gel packed in a specific column (34). [Pg.52]

Standard Chemical Pump. In 1961, the American National Standards Institute (ANSI) iatroduced a chemical pump standard (29), known as ANSI B73.1, that defined common pump envelope dimensions, connections for the auxiUary piping and gauges, seal chamber dimensions, parts mnout limits, and baseplate dimensions. This definition was to ensure the user of the availabiUty of iaterchangeable pumps produced by different manufacturers, as well as to provide plant designers with standard equipment. A typical ANSI chemical pump, known as of the mid-1990s as ASME B73.1M-1991, is shown ia Figure 6. [Pg.292]

In 1903, Rutherford and associates were finally able to deflect the a-rays by electric and magnetic fields, showing that these are positively charged. Measurement of the charge-to-mass ratio indicated that a-rays were of atomic dimensions. In 1908 definitive experiments showed a-rays to be doubly chaiged helium atoms, ie, helium nuclei. [Pg.443]

Proc., 65(3), 45 (1986)] is preferred. To use this and alternate models, dimensional characteristics of structured packing must be defined. Figure 14-51 shows nomenclature and definitions of key dimensions. Not shown, but also important, is the angle the corrugations make with the horizontal (usu y 45 or 60°). Then the Rocha et al. predictive equation is ... [Pg.1388]

If L is a charac teristic dimension of a ciystal of selected material and shape, the rate of growth of a ciystal face that is perpendicular to L is, by definition,... [Pg.1658]


See other pages where Dimensions Definition is mentioned: [Pg.642]    [Pg.928]    [Pg.12]    [Pg.19]    [Pg.172]    [Pg.173]    [Pg.481]    [Pg.91]    [Pg.286]    [Pg.337]    [Pg.642]    [Pg.928]    [Pg.12]    [Pg.19]    [Pg.172]    [Pg.173]    [Pg.481]    [Pg.91]    [Pg.286]    [Pg.337]    [Pg.871]    [Pg.2609]    [Pg.2789]    [Pg.3060]    [Pg.94]    [Pg.14]    [Pg.367]    [Pg.21]    [Pg.61]    [Pg.337]    [Pg.482]    [Pg.240]    [Pg.193]    [Pg.103]   
See also in sourсe #XX -- [ Pg.2 ]




SEARCH



Dimension classical definition

Fractal dimension, definition

Mass fractal dimension, definition

Surface fractal dimension, definition

© 2024 chempedia.info