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Import constraint

The most favourable distribution is the one with the highest weight, and this corresponds to the configuration with just one pcirticle in each energy level (W = Nl). However, there are two important constraints on the system. First, the total energy is fixed ... [Pg.361]

Another important constraint comes from the pressure drop across the catalytic bed, which must be kept to a minimum to avoid a loss in engine power and performance. This requirement is satisfied by a very shallow pellet bed of no more than ten pellets deep, a monolithic structure with many open parallel channels, or a pile of metallic screens and saddles. [Pg.75]

Condition (3.19) is usually satisfied in processes of vibrational dephasing [41, 130, 131, 132], Because of this condition the dephasing is weak and the effect of rotational structure narrowing is pronounced. A much more important constraint is imposed by inequality (3.18). It shows that perturbation theory must be applied to a rather dense medium and even then only the central part of the spectrum (at Aa> < 1/t , 1/tc) is Lorentzian. [Pg.96]

Croup II (Ca, Na). This group includes the remaining cations with relatively long residence times. One important constraint is the charge balance of seawater, re-arranged in the following format ... [Pg.270]

In addition to these relatively simple liquid phase aqueous systems, it is necessary to identify situations in which any of these aqueous phase reservoirs come into physical and chemical contact with solid surfaces (e.g., rocks, biomass, sediments, soils, magma etc.). In general, the presence of two or more phases (liquid plus one or more solid phase) provides important constraints on the chemical reactions that may occur within the system as a whole. [Pg.422]

This likelihood function has to be maximized for the parameters in f. The maximization is to be done under a set of constraints. An important constraint is the knowledge of the peak-shapes. We assume that f is composed of many individual... [Pg.557]

In sum, initial values place important constraints on diagenesis. We are... [Pg.386]

Theoretical models of galactic chemical evolution offer varying predictions of how the gradient should change with time, so using open clusters to measure that time-dependence can provide important constraints on model parameters. [Pg.7]

An other important constraint comes from the 12C/13C ratios derived in AGB C-stars. Some discrepancy still exists among different authors concerning the typical 12C/13C ratio in these stars (see e.g. de Laverny Gustafsson 1998). However, all the authors agree in the fact that there are a significant number of... [Pg.26]

At the same time, the abundance ratios among the elements heavier than Al, at least through the Fe peak, do not show any detectable variation in any known GC (except, of course, iv Cen). The rock steady abundances for these elements requires explanation as well, and places important constraints on the formation mechanisms of GCs. [Pg.104]

The shell model can be modified to take into account further aspects of the solid being modeled. In particular, angular-dependent terms can be added. These are important in materials such as silicates where the tetrahedral geometry about the silicon atoms is an important constraint. These aspects can be explored via the sources listed in Further Reading at the end of this chapter. [Pg.74]

The hyper-acidic water seems to be contained within the Banyu Pahit stream valley, potentially constraining the extent of the Ijen hydrothermal system and placing important constraints on the hydrology of the Banyu Pahit valley. [Pg.264]

Weeds constitute one of the major problems in agriculture. They are an important constraint on yield in most crops across the world. These days, growers spend much money on weed control. About 6 million ton of herbicides was sold in the world in 2006 and herbicides are the most used pesticides they form approximately 38% of the total amount of pesticides (FAO 2006). Nowadays, an effort to tighten rules for authorization and application of pesticides, research and develop products that are target-specific, degrade quickly and do not accumulate in the food chain, exists in... [Pg.380]

Before discussing in detail specific molecular mixing models, it is useful to first state a few important constraints that can be derived by computing expected values. The first constraint follows from45... [Pg.281]

Another important constraint especially for existing industrial converters is the volume available in the reactor for the catalyst. Accordingly, the reaction rate per unit bed volume... [Pg.320]

The European bubonic plague of 1347 killed one-third of the population of Europe. It is the largest single plague ever recorded. The disappearance of the Aztec civilization was spurred by smallpox and measles introduced by Hernando Cortes and his band of Spanish invaders. The same diseases also decimated Native Americans in what is now the United States. Much more recently, the influenza epidemic of 1918 killed an estimated 40 million people worldwide. Malaria continues to be a major problem for people and their countries today in areas in which it is endemic. AIDS, tuberculosis, influenza, hepatitis, pneumonia, and a lengthy list of parasitic infections continue as important constraints on the welfare of people throughout the world. [Pg.317]

The need for lead compounds (item 6) is a particularly critical one since our ability to design compounds to affect enzymes, receptors, or other biochemical targets initio is very limited. However, there is an important constraint in respect to the physical properties of lead compounds. The need for favorable pharmacokinetics (item 7) is a factor which may be overlooked. [Pg.104]

As previously discussed, when developing necessary conditions for N-representability, it is useful to consider the subset of Hamiltonians whose ground-state energy is zero. Applying this idea to the Slater hull, the following Hamiltonians arise as important constraints ... [Pg.456]

While the P, Q, and G conditions give no new constraints on the diagonal elements of the 2-matrix, they provide important constraints for the off-diagonal elements. [Pg.468]

The A-representability constraints presented in this chapter can also be applied to computational methods based on the variational optimization of the reduced density matrix subject to necessary conditions for A-representability. Because of their hierarchical structure, the (g, R) conditions are also directly applicable to computational approaches based on the contracted Schrodinger equation. For example, consider the (2, 4) contracted Schrodinger equation. Requiring that the reconstmcted 4-matrix in the (2, 4) contracted Schrodinger equation satisfies the (4, 4) conditions is sufficient to ensure that the 2-matrix satisfies the rather stringent (2, 4) conditions. Conversely, if the 2-matrix does not satisfy the (2, 4) conditions, then it is impossible to construct a 4-matrix that is consistent with this 2-matrix and also satisfies the (4, 4) conditions. It seems that the (g, R) conditions provide important constraints for maintaining consistency at different levels of the contracted Schrodinger equation hierarchy. [Pg.479]

The important points to note are that often the vast majority of compounds are tested just once, at a single concentration, and the results are converted to a percentage inhibition. The result of this is that the error associated with any data point may be quite large and the dynamic range of the data is limited to essentially a range of 1-100. As will be discussed below, this places important constraints on the significant information that can be successfully extracted from HTS data. [Pg.87]

Is there a certain kind of anatomy that is most likely to mediate conscious activity Also, are there any kinds of anatomical arrangements that are unlikely to orchestrate the unified brain state we know of as consciousness There are likely to be important constraints governing what is suitable anatomy for underlying consciousness in contrast to what kind of anatomy is favorably suited for unconscious information processing. These constraints are important clues as to how different neurochemical circuits divide up the manifold tasks taken on by the CNS. [Pg.27]

Many of the most effective constraints set well-defined limits to the data function (or its spectrum) beyond which the correct function is not allowed to go. An important example of this type of constraint is nonnegativity, whereby the correctly restored function is not allowed to extend below the zero baseline and thereby take on nonphysical negative values. This is an appropriate constraint for spectroscopy and optical images. A further example of the constraints of fixed limits is that of an upper bound to the values of the restoration. Another important constraint of this type is that of finite extent, for which no deviations from zero are allowed for the spatial function over those intervals on the spatial axis that lie outside the known... [Pg.269]

Except for special cases, the differences among the restorations produced by the various criteria are usually small and inconsequential. In a gross sense, the restorations produced by the methods mentioned in this section that apply many of the important constraints are usually much closer to the original undistorted function, even in the presence of moderate to high noise levels. The primary objective in initiating these restoration procedures is thus largely accomplished. [Pg.275]

The documented mineralogy of meteorites is quite varied more than 300 different meteoritic minerals have been reported (tabulated by Lodders and Fegley, 1998). In the list below we focus only on those minerals that are especially important, either because they are volumetri-cally abundant or provide important constraints on meteorite formation. [Pg.160]

The velocities deduced for seismic waves emanating from the core revealed that it must consist of very dense material, but its composition remained a mystery. However, cosmochemical reasoning provided important constraints. The core comprises approximately... [Pg.219]


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See also in sourсe #XX -- [ Pg.65 ]

See also in sourсe #XX -- [ Pg.65 ]




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Thermodynamic constraints importance

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