Big Chemical Encyclopedia

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

Articles Figures Tables About

System point

It is convenient to analyse tliese rate equations from a dynamical systems point of view similar to tliat used in classical mechanics where one follows tire trajectories of particles in phase space. For tire chemical rate law (C3.6.2) tire phase space , conventionally denoted by F, is -dimensional and tire chemical concentrations, CpC2,- are taken as ortliogonal coordinates of F, ratlier tlian tire particle positions and velocities used as tire coordinates in mechanics. In analogy to classical mechanical systems, as tire concentrations evolve in time tliey will trace out a trajectory in F. Since tire velocity functions in tire system of ODEs (C3.6.2) do not depend explicitly on time, a given initial condition in F will always produce tire same trajectory. The vector R of velocity functions in (C3.6.2) defines a phase-space (or trajectory) flow and in it is often convenient to tliink of tliese ODEs as describing tire motion of a fluid in F with velocity field/ (c p). [Pg.3055]

Figure 1. Phase diagram of the Ti - H system. Points are related to the anomalous ductility behavior. Figure 1. Phase diagram of the Ti - H system. Points are related to the anomalous ductility behavior.
Elleci ol applying inlet dampers lo the tan in Figure 1. Separ.itc SP and BHP curves are lor each vane seiimg. Fan opeialmg points at these settings are delcnumed by system (points where system curve intersects SP and BHP fan eui ves). [Pg.553]

Since ice storage tanks are used in HVAC system, the performance should be evaluated from system point of view. If the water distribution system had poor performance, performance of tank would be worse than its design value. Furthermore, heat load characteristics of the building also have large relation to system performance. System performance will be different for the building that has peaky load comparing to the building with flat load. [Pg.306]

Consider a small region in phase space, At, sufficiently small that the density is essentially constant within this region. The number of system points An = qAt. If the surface of the element is always determined by the same system points originally in the surface, the behaviour of the element can be followed as a function of time. None of the points within the surface may escape and there are no sources or sinks of system points. Consequently... [Pg.437]

As an alternative to drawing the equilibrium curve for the system, point values may be calculated from ... [Pg.138]

The intrinsic safety is however affected by both the process equipment and the properties of the chemical substances present in the process. Therefore also the index should reflect this fact. We have included parameters into the list (Table 5) to represent the process aspects of the inherent safety. These parameters are the type of equipment involved and the safety of process structure which describe the process configuration from a system point of view. Also a third parameter to describe the interaction (reactivity) of the chemicals present in the process has been included, since this is an obvious source of risk. [Pg.43]

It is also interesting to note that the halogenated furanones were often stable in the distribution system and in simulated distribution system tests. Previous controlled laboratory studies had suggested that halogenated furanones, particularly MX, may not be stable in distribution systems. In at least five instances, MX levels actually increased in concentration from the plant effluent to the distribution system point sampled [11, 12]. Occasionally, MX levels decreased in the distribution system, but in these instances, it was still generally present at detectable levels. [Pg.108]

Adequate dust collection systems point of use are recommended in areas where materials are handled. Where recovery of product is required from the dust collector systems, it is desirable that the system be dedicated to a single process or product line. [Pg.36]

From an electronic control system point of view, it should be possible in the near future to reach incrementing rates of 50-100 MHz, and provided adequate current density can be delivered to a practical resist, a throughput of about 5,125 mm wafers per hour will be obtained. [Pg.24]

The functionality of bromelain-hydrolyzed succinylated fish protein has been tested in a dessert topping, a souffle, and both chilled and frozen desserts ( ). Taste panel evaluations revealed that no fishlike odors or flavors were detected. The compatibility of enzyme-treated fish protein in these diverse food systems points up the potential value of such a product to the food processing industry. [Pg.294]

Figure 16.5. Supersaturation behavior, (a) Schematic plot of the Gibbs energy of a solid solute and solvent mixture at a fixed temperature. The true equilibrium compositions are given by points b and e, the limits of metastability by the inflection points c and d. For a salt-water system, point d virtually coincides with the 100% salt point e, with water contents of the order of 10-6 mol fraction with common salts, (b) Effects of supersaturation and temperature on the linear growth rate of sucrose crystals [data of Smythe (1967) analyzed by Ohara and Reid, 1973],... Figure 16.5. Supersaturation behavior, (a) Schematic plot of the Gibbs energy of a solid solute and solvent mixture at a fixed temperature. The true equilibrium compositions are given by points b and e, the limits of metastability by the inflection points c and d. For a salt-water system, point d virtually coincides with the 100% salt point e, with water contents of the order of 10-6 mol fraction with common salts, (b) Effects of supersaturation and temperature on the linear growth rate of sucrose crystals [data of Smythe (1967) analyzed by Ohara and Reid, 1973],...
Chapter 2 introduces the essential principles of modeling and simulation and their relation to design from a systems point of view. It classifies systems based on system theory in a most general and compact form. This chapter also introduces the basic principles of nonlinearity and its associated multiplicity and bifurcation phenomena. More on this, the main subject of the book, is contained in Appendix 2 and the subsequent chapters. [Pg.7]

Once it is conLrmed that a simple LBDDS provides measurable improvement in bioavailability, the next step is development and optimization of the formulation. Currently there are no deLnitive tests that will translate vitro measures tan vivo performance. At the same time, this does not mean that development of such formulations should be conducted using a trial-and-error approach. Pouton s classiLcation system points out that the factors to be considered in interpreitingvtde behavior of the formulations are effects of lipolysis, dispersibility, and solubilization capacity on dilution. It is important to understand that the balance of each of these effects will depend on the drug being formulated, and that there is unlikely to be a universal formulation that works for all compounds. [Pg.238]

A large potential source of systematic uncertainty is due to the finite image resolution. The measured image can be described as the convolution of the true sharp image with the imaging system point spread function, PSF. The PSF is reasonably approximated by a Gaussian,... [Pg.192]

Table 2.4 shows the crystal systems, point groups, and the corresponding space groups. The numbers for space groups are those as derived and numbered by Schoenflies. The space groups isomorphous to each point group are indicated by a superscript (e.g., Number 194, D6/,4). [Pg.16]

Table 2.4. Space groups, crystal systems, point groups, and the Hermann-Mauguin Symbols. Table 2.4. Space groups, crystal systems, point groups, and the Hermann-Mauguin Symbols.
Fig. 5.1.1 Configuration space showing the regions for reactants (r) and products (pj). ti is an example of a trajectory that leads to the formation of products pi. S(pl,r) is part of the dividing surface between r and pi, where the system points have an outward velocity from the reactant region. Fig. 5.1.1 Configuration space showing the regions for reactants (r) and products (pj). ti is an example of a trajectory that leads to the formation of products pi. S(pl,r) is part of the dividing surface between r and pi, where the system points have an outward velocity from the reactant region.
We have seen that a classical system is represented in phase space by a point, and that an ensemble of identical systems will therefore be represented by a cloud of points. The distribution of system points is determined by the constraints we have imposed on the system, e.g., constant number of particles, constant volume, and constant energy (AWE-ensemble) or constant number of particles, constant volume, and constant temperature (NVT-ensemble). [Pg.113]

This cloud of system points is very dense, since we consider a large number of systems, and we can therefore define a number density p(p, q, t) such that the number of systems in the ensemble whose phase-space points are in the volume element dp dq about (p, q) at time t is p(p,q,t)dpdq. Clearly, we must have that... [Pg.113]

We consider an ensemble of systems each containing n atoms. Thus, q = (<71, , < 3n), P = (pi, , P3n), and dpdq = Ilf" (dp dqi). We assume that all interactions are known. As time evolves, each point will trace out a trajectory that will be independent of the trajectories of the other systems, since they represent isolated systems with no coupling between them. Since the Hamilton equations of motion, Eq. (4.63), determine the trajectory of each system point in phase space, they must also determine the density p(p, q, t) at any time t if the dependence of p on p and q is known at some initial time to. This trajectory is given by the Liouville equation of motion that is derived below. [Pg.113]

Let us determine the change in p with time at a given position (p, q) in phase space. We surround the point with a small volume element Q, sufficiently small to make the value of p(p, q, t) the same at all points in the volume element, and sufficiently large to contain enough system points so that p is well defined and not dominated by large fluctuations. Then the change in the number of system points per second in 0, is equal to the net flow of system points across the bounding surface S(Q.) of Q, that is,... [Pg.113]


See other pages where System point is mentioned: [Pg.155]    [Pg.31]    [Pg.284]    [Pg.126]    [Pg.106]    [Pg.245]    [Pg.370]    [Pg.371]    [Pg.438]    [Pg.139]    [Pg.114]    [Pg.20]    [Pg.250]    [Pg.594]    [Pg.174]    [Pg.46]    [Pg.196]    [Pg.524]    [Pg.351]    [Pg.433]    [Pg.5]    [Pg.281]    [Pg.52]    [Pg.531]    [Pg.364]    [Pg.297]    [Pg.653]    [Pg.272]    [Pg.113]   
See also in sourсe #XX -- [ Pg.257 ]

See also in sourсe #XX -- [ Pg.200 ]




SEARCH



© 2024 chempedia.info