Motivations for use

This introductory section continues with a subsection that presents the general motivation for using symmetry and ends with a short subsection that lists the various types of molecular symmetry. 

Rotational syimnetry is used here as an example to explain the motivation for using syimnetry in molecular physics it will be discussed in more detail in section AT4.3.2. 

As stated earlier, the main motivation for using either PCA or PCA is to construct a low-dimensional representation of the original high-dimensional data. The notion behind this approach is that the effective (or essential, as some call it [33]) dimensionality of a molecular conformational space is significantly smaller than its full dimensionality (3N-6 degrees of freedom for an A-atom molecule). Following the PCA procedure, each new... 

EPRI NP-5664 is a study based on interviews of personnel at 10 utilities and 15 NRC personnel regarding the usefulness of PSA (they use the term PRA - probabilistic risk assessment). The general utility motivation for using PSA is to demonstrate an acceptably low level of risk to the NRC. Some utilities applied PSA to individual systems, functions, or issues. These smaller [ir(>grams served to train a PSA cadre and introduce PSA to other utility personnel and management. 

As another example of calculation and dimensioning of pneumatic conveying systems we consider an ejector shown in Fig. 14.20. In fluidized bed combus tion systems a part of the ash is circulated with the hot flue gas. The task of the ejector, is to increase the pressure of the circulating gas to compensate the pressure losses of the circulation flow. The motivation for using an ejector, rather than a compressor, is the high temperature of the flue gas. The energy... 

Like enzymes, whole cells are sometime immobilized by attachment to a surface or by entrapment within a carrier material. One motivation for this is similar to the motivation for using biomass recycle in a continuous process. The cells are grown under optimal conditions for cell growth but are used at conditions optimized for transformation of substrate. A great variety of reactor types have been proposed including packed beds, fluidized and spouted beds, and air-lift reactors. A semicommercial process for beer used an air-lift reactor to achieve reaction times of 1 day compared with 5-7 days for the normal batch process. Unfortunately, the beer suffered from a mismatched flavour profile that was attributed to mass transfer limitations. 

Special considerations are required in estimating paraimeters from experimental measurements when the relationship between output responses, input variables and paraimeters is given by a Monte Carlo simulation. These considerations, discussed in our first paper 1), relate to the stochastic nature of the solution and to the fact that the Monte Carlo solution is numerical rather than functional. The motivation for using Monte Carlo methods to model polymer systems stems from the fact that often the solution... 

There is a variety of motivations for using molecular calculations, some of which are of interest for the future evolution of theoretical chemistry. 

The third contribution is particularly devoted to the concept of so-called single source precursors (SSPs). SSPs contain all the atoms of the different elements necessary for the deposition of the desired material in one single molecule. One motivation for using this concept is to simplify the accompanying gas-phase reactions and thus reduce the process parameters to be controlled and optimised. However, SSPs may offer a unique chance of depositing metastable materials that cannot be derived by other methods. M. Veith and S. Mathur provide such an example in their paper entitled Single-Source-Precursor CVD Alkoxy and Siloxy Aluminum Hydrides . 

Abstract The theoretical basis for the quantum time evolution of path integral centroid variables is described, as weU as the motivation for using these variables to study condensed phase quantum dynamics. The equihbrium centroid distribution is shown to be a well-defined distribution function in the canonical ensemble. A quantum mechanical quasi-density operator (QDO) can then be associated with each value of the distribution so that, upon the application of rigorous quantum mechanics, it can be used to provide an exact definition of both static and dynamical centroid variables. Various properties of the dynamical centroid variables can thus be defined and explored. Importantly, this perspective shows that the centroid constraint on the imaginary time paths introduces a non-stationarity in the equihbrium ensemble. This, in turn, can be proven to yield information on the correlations of spontaneous dynamical fluctuations. This exact formalism also leads to a derivation of Centroid Molecular Dynamics, as well as the basis for systematic improvements of that theory. 

The motivation for using proteases to alter protein functionality in food is two-fold (a) The need to convert food source proteins to more palatable or useful forms (increasingly important with the advent of "novel" proteins) and (b) the rather specific way in which proteases accomplish this goal. 

High pressure technology today - motivations for using high pressure... 

Our last example does not involve the rate of a chemical reaction, but instead, the effect of temperature on diffusion rates [25]. One of the motivations for using microelectrodes as in the previous example is to allow fast experiments without appreciable iR drop. When used in the opposite extreme of very small scan rates, microdisk electrodes produce steady-state voltammograms that have the same sigmoidal shape as dc polarograms and RDE voltammograms (cf. Chap. 12). 

This solution has the advantage of being very simple, but the drawback of being expensive in terms of calculations, even when tabulated sinusoids are used in Eq. (7.17). In fact, additive synthesis (of which Eq. (7.17) is an example) can be implemented at a much lower cost by use of the Fourier transform [Rodet and Depalle, 1992]. This last remark is a strong motivation for using the following alternative ... 

Many researchers point to five factors that can predict the likelihood of marijuana use by teenagers awareness, access, motivations for use, reassurance about safety, and a willingness to break social norms by violating the law. 

The primary remaining motive for using frozen sections in routine practice is the need for a quick examination that eliminates the time required for fixation, processing and de-waxing. Frozen tissue sections are also used when direct or indirect immunofluorescence is the detection method, in which case formalin fixation can produce weaker results. Frozen sections should be fixed with acetone (room temperature, five seconds) before storing. They are then re-processed in acetone (4 °C, 10 minutes) and then re-hydrated in buffer for five minutes before immunostaining. 

Considering the overall strategy adopted, what could be considered the main motive for using the D-threose derivative 2 in the synthesis ... 

As yet, the use of isothermal MD simulations for the study of small clusters has been limited to one study, of Ar,3. We simply note here that the real variable version of Nose s method was employed for the cluster study, and refer the reader to several reviews of this and related constant-temp>erature MD methods in the present literature. A motivation for use of MD in the isothermal simulations has been to calculate dynamic quantities. With respect to the cluster simulations, it was desirable to be able to distinguish different forms of the cluster as disparate phases and not simply different solid isomers, particularly for temp>eratures inside the coexistence region. 

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