First approach

From these data, a first approach is to develop linear models using a relation of the following type ... 

A first approach to testing, ASTM D 1094, is to create, using a potassium phosphate reagent, a separation between two layers, hydrocarbon and aqueous. The degree of separation of the two phases is estimated by attributing a grade from 1 to 3 and the appearance of the interface by five levels of observation 1, lb, 2, 3, and 4. The specifications establish both the quality of separation (2 is the maximum) and the appearance of the interface (lb maximum). 

This paper compares experimental data for aluminium and steel specimens with two methods of solving the forward problem in the thin-skin regime. The first approach is a 3D Finite Element / Boundary Integral Element method (TRIFOU) developed by EDF/RD Division (France). The second approach is specialised for the treatment of surface cracks in the thin-skin regime developed by the University of Surrey (England). In the thin-skin regime, the electromagnetic skin-depth is small compared with the depth of the crack. Such conditions are common in tests on steels and sometimes on aluminium. 

The first approach - quality through NDT laboratory accreditation - is widely used both in Western and Eastern Europe and is realized on rules and procedures specified in the EN 45000 series and EAL -G15 Accreditation for Non-Destructive Testing Laboratories . 

Otlier expressions for tire diffusion coefficient are based on tire concept of free volume [57], i.e. tire amount of volume in tire sample tliat is not occupied by tire polymer molecules. Computer simulations have also been used to quantify tire mobility of small molecules in polymers [58]. In a first approach, tire partition functions of tire ground... 

Series expansion Smith and van Gunsteren [4] investigated the first approach expanding the free energy as a function of the coupling parameter A into a T ylor series around a given reference state, A = 0,... 

It can be said that these three main strategies have been applied equally and very often in combination. Basically, the first approach implies the use of a faster computer or a parallel architecture. To some extent it sounds like a brute force approach but the exponential increase of the computer power observed since 1970 has made the hardware solution one of the most popular approaches. The Chemical Abstracts Service (CAS) [10] was among first to use the hardware solution by distributing the CAS database onto several machines. 

Our first approach took resort in simple resonance theory [36, 37]. For each conjugated nr-system aU resonance structures were generated, such as those shown in Figure 7-5. 

With samples that are difficult to dissolve, the first approach is usually to try digesting the sample with an acid or base. Table 7.2 lists the most commonly used acids and bases and summarizes their use. Digestion is commonly carried out in an open container, such as a beaker, using a hot plate as a source of heat. The chief advantage of this approach is its low cost as it requires no special equipment. Volatile reaction products, however, are lost, leading to a determinate error if analyte is included among the volatile substances. 

Technological History (26,54—61). As a first approach, there are three groups of components supports, paint media, and pigments. The support is the substrate upon which the paint layers are laid down. This can be a specially prepared area on a wall for a wall painting, a wooden panel as in a panel painting, or a fabric in canvas paintings. Paper is a prevalent support in Oriental painting. Other supports are encountered less frequently, eg, metal panels such as copper sheet. 

There are two principal approaches to the biological control of weeds (483—485). The first approach is referred to as classical or inoculative biological weed control. Plants that have been introduced to areas outside of their natural range often encounter fewer growth and seed dissemination... 

Corrosion control requires a change in either the metal or the environment. The first approach, changing the metal, is expensive. Also, highly alloyed materials, which are resistant to general corrosion, are more prone to failure by localized corrosion mechanisms such as stress corrosion cracking. 

As mentioned previously, ternaiy mixtures can be represented by 125 different residue curve maps or distillation region diagrams. However, feasible distillation sequences using the first approach can be developed for breaking homogeneous binaiy azeotropes by the addition of a third component only for those more restricted systems that do not have a distillation boundaiy connected to the azeotrope and for which one of the original components is a node. For example, from... 

There are several widely used approaches for developing perspective about the significance of absolute risk estimates (Figure 16). The first approach is to compare the risk estimates to historical experience within your company, looking for similar events. Most companies have safety and loss recordkeeping programs that date back many years. But if directly related data are sparse, you may widen your comparison to extrapolate from near-miss incidents that could have caused the event of interest. You will not, however, frequently find solace from the company data—or even comparable industry data. 

The first approach is based on introducing simple velocity or position rescaling into the standard Newtonian MD. The second approach has a dynamic origin and is based on a refonnulation of the Lagrangian equations of motion for the system (so-called extended Lagrangian formulation.) In this section, we discuss several of the most widely used constant-temperature or constant-pressure schemes. 

The first approach has been important commercially. The monomer most commonly used is a-methylstyrene (see Section 16.11), whose polymer has a Tg of about 120°C. The heat distortion temperature of the resultant-ABS type polymer will depend on the level of replacement of styrene by the a-methyl-styrene. (It may be noted in passing that a-methylstyrene-acrylonitrile binary copolymers have been available as alternatives to styrene-acrylonitrile materials but have not achieved commercial significance.)... 

The goals and the final quantities to be obtained determine the method to be used. As a first approach, it is always worth checking if a documented and proven method exists. Standardized methods are often the best. They are developed by experts in the field and are usually of a high quality and are well documented. Frequently no standards can be applied and generally known methods have to be relied on. Sometimes situations occur when the whole of the measurement procedure has to be tailored for the specific situation. This is a very demanding task and considerable experience is required. 

There are two basic approaches to handling the particle collection in an electrostatic gas-cleaning system. The first approach is based on the assump-... 

For an existing process plant, the designer has the opportunity to take measurements of the fume or plume flow rates in the field. There are two basic approaches which can be adopted. For the first approach, the fume source can be totally enclosed, and a temporary duct and fan system installed to capture the contaminant. For this approach, standard techniques can be used to measure gas flow rates, gas compositions, gas temperatures, and fume loadings. From the collected fume samples, the physical and chemical characteristics can be established using standard techniques. For most applications, this approach is not practical and not very cost effec tive. For the second approach, one of three field measurement techniques, described next, can be used to evaluate plume flow rates and source heat fl uxes. 

Computer simulations of bulk liquids are usually performed by employing periodic boundary conditions in all three directions of space, in order to eliminate artificial surface effects due to the small number of molecules. Most simulations of interfaces employ parallel planar interfaces. In such simulations, periodic boundary conditions in three dimensions can still be used. The two phases of interest occupy different parts of the simulation cell and two equivalent interfaces are formed. The simulation cell consists of an infinite stack of alternating phases. Care needs to be taken that the two phases are thick enough to allow the neglect of interaction between an interface and its images. An alternative is to use periodic boundary conditions in two dimensions only. The first approach allows the use of readily available programs for three-dimensional lattice sums if, for typical systems, the distance between equivalent interfaces is at least equal to three to five times the width of the cell parallel to the interfaces. The second approach prevents possible interactions between interfaces and their periodic images. 

In the first approach, a vapor cloud s potential explosive power is proportionally related to the total quantity of fuel present in the cloud, whether or not it is within flammable limits. This approach is the basis of conventional TNT-equivalency methods, in which the explosive power of a vapor cloud is expressed as an energetically equivalent charge of TNT located in the cloud s center. The value of the proportionality factor, that is, TNT equivalency, is deduced from damage patterns observed in a large number of vapor cloud explosion incidents. Consequently, vapor cloud explosion-blast hazard assessment on the basis of TNT equivalency may have limited utility. 

A second direct route to an extended 3,4-dihydro-j8-carbolinium system (120) using the Bischler-Napieralski ring closure is based on the cyclization of intermediates of general structure 118. Three approaches to intermediates of this type have been developed in connection with stereospecific syntheses in the indole alkaloid field. The first approach, introduced independently by Stork and Hill and by van Tamelen and co-workers and often used... 

The line of reasoning that leads from morphine to the 4-phenyl-piperidines is so clear—if unhistoric—as to demand exposition in an integral chapter. The chronologically oriented chapter on the development of the local anesthetics is included specifically to give the reader some appreciation of one of the first approaches to drug development. 

Perhaps the first approach to the modern conception of the gas-turbine power plant was that described in... 

As a first approach to the principles which govern the behaviour of metals in specific environments it is preferable for simplicity to disregard the detailed structure of the metal and to consider corrosion as a heterogeneous chemical reaction which occurs at a metal/non-metal interface and which involves the metal itself as one of the reactants (cf. catalysis). Corrosion can be expressed, therefore, by the simple chemical reaction ... 

When an antagonist produces parallel shifts to the right of the dose-response curve with no diminution of the maximal response, the first approach used to quantify potency is Schild analysis (see Section 6.3.1). In cases where the value of a is low (i.e., a = 0.01), a tenfold concentration range of the antagonist would cause shifts commensurate with those produced by a simple competitive antagonist. 

The noteworthy successes of a relevant model study12 provided the foundation for Merck s thienamycin syntheses. In the first approach (see Schemes 2 and 3), the journey to the natural product commences from a readily available derivative of aspartic acid this route furnishes thienamycin in its naturally occurring enantiomeric form, and is noted for its convergency. During the course of this elegant synthesis, an equally impressive path to thienamycin was under parallel development (see Schemes 4 and 5). This operationally simple route is very efficient (>10% overall yield), and is well suited for the production of racemic thienamycin on a commercial scale.. x... 

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