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A systematic development of relativistic ECPs is possible within wavefunction-based approaches, which offer a hierarchy of approximations and the possiblity to converge, at least in principle, to the exact solution. Thus it is possible to [Pg.806]


Reservoirs containing low compressibility oil, having small amounts of dissolved gas, will suffer from large pressure drops after only limited production. If the expansion of oil is the only method of supporting the reservoir pressure then abandonment conditions (when the reservoir pressure is no longer sufficient to produce economic quantities of oil to the surface) will be reached after production of probably less than 5% of the oil initially in place. Oil compressibility can be read from correlations. [Pg.109]

CT offers the opportunity to examine slices through the sample non-destructively and is therefor the only method for measuring exterior and also interior part coordinates without mechanical cutting of the object. [Pg.492]

Unconstrained optimization methods [W. II. Press, et. ah, Numerical Recipes The An of Scieniific Compulime.. Cambridge University Press, 1 9H6. Chapter 101 can use values of only the objective function, or of first derivatives of the objective function. second derivatives of the objective function, etc. llyperChem uses first derivative information and, in the Block Diagonal Newton-Raphson case, second derivatives for one atom at a time. TlyperChem does not use optimizers that compute the full set of second derivatives (th e Hessian ) because it is im practical to store the Hessian for mac-romoleciiles with thousands of atoms. A future release may make explicit-Hessian meth oils available for smaller molecules but at this release only methods that store the first derivative information, or the second derivatives of a single atom, are used. [Pg.303]

This elimination of the diazonium group is therefore a very valuable reaction, as it affords almost the only method by which nitro and primary amino groups directly attached to the benzene ring can be eliminated. [Pg.202]

Traditionally, molecular mechanics has not been the method of choice for predicting transition structures. However, since it is the only method viable for many large molecules, some elforts have been made to predict transition structures. Since the bonds are explicitly defined in molecular mechanics methods, it is not possible to simply find a point that is an energy maximum, except for conformational intermediates. [Pg.148]

The only method that yields the 2-unsubstituted thiazoie derivatives directly involves the condensation of a-haloketones with thioformamide. As in the case of previously reported a-haloaldehydes, yields are better when more reactive bromoketones are used instead of a-chloroketones. Cyclization can be achieved by adding ketones dissolved in dioxane in small quantities to the thioformamide formed in situ at below 40°C. The temperature is kept below 70°C during the addition, and then the... [Pg.175]

Begin by asking the question What kind of compound is the target molecule and what methods can I use to prepare that kind of compound The desired product has a bromine and a hydroxyl on adjacent carbons it is a vicinal bromohydrin The only method we have learned so far for the preparation of vicinal bromohydrms involves the reaction of alkenes with Bi2 m water Thus a reasonable last step is... [Pg.265]

The only method utilized commercially is vapor-phase nitration of propane, although methane (70), ethane, and butane also can be nitrated quite readily. The data in Table 5 show the typical distribution of nitroparaffins obtained from the nitration of propane with nitric acid at different temperatures (71). Nitrogen dioxide can be used for nitration, but its low boiling point (21°C) limits its effectiveness, except at increased pressure. Nitrogen pentoxide is a powerful nitrating agent for alkanes however, it is expensive and often gives polynitrated products. [Pg.101]

Other potential synthetic methods include fermentation (qv) of certain carbohydrates (qv), oxidation of propane, hydrogenation of acetone, and hydrolysis of isopropyl acetate. The hydrogenation of by-product acetone is the only method practiced commercially. [Pg.107]

Capacity. Pumps deHver a certain capacity, Q, sometimes referred to as flow, which can be measured directly by venturi, orifice plate (11), or magnetic meters (12) (see Flow measurement). The indirect way to determine capacity is often used. Whereas this method is less accurate than applying a flow meter, it often is the only method available in the field. The total head is measured and the capacity found from the pump head—capacity (H— curve (Fig. 2). More recently, sonic flow meters (13) have been used, which can be installed on the piping without the need for pipe disassembly. These meters are simple to use, but require relatively clean single-phase Hquid for reHable measurements. [Pg.288]

There are four key advantages to handling separated materials (/) separated materials systems are far less labor-intensive than other collection schemes (as mentioned eadier, labor costs are the largest component of most recovery facihties operating expenses) (2) the equipment needed to handle separated material is relatively simple and inexpensive (J) source separation is often the only method of resource recovery suitable for small communities ... [Pg.544]

The properties of the finished beer vary with the type of beer and place of origin. The figures in Table 1 do not, however, show much about the quaUty of the beer this can only partly be expressed in figures based on objective measurements. The quahty consists of aroma, taste, appearance, (color, clarity) formation, and stabiUty of foam. Of these, the first two ate still inaccessible to objective measurement. Although the aroma of a product is determined by the quantity of volatile alcohols, etc, the quahty of the product caimot be expressed in those terms. Appearance, foam formation, and foam stabiUty can be evaluated more easily. For judgment on taste and aroma, taste-testing panels ate the only method. [Pg.13]

Steam stripping or steaming-out (Eig. 3), is the only method currently used in the United States to remove elemental bromine from the brine. This method is economical for brines containing bromine above 1000 ppm. [Pg.409]

Not all of the ions in the diffuse layer are necessarily mobile. Sometimes the distinction is made between the location of the tme interface, an intermediate interface called the Stem layer (5) where there are immobilized diffuse layer ions, and a surface of shear where the bulk fluid begins to move freely. The potential at the surface of shear is called the zeta potential. The only methods available to measure the zeta potential involve moving the surface relative to the bulk. Because the zeta potential is defined as the potential at the surface where the bulk fluid may move under shear, this is by definition the potential that is measured by these techniques (3). [Pg.178]

These unbalance forces increase as a function of making the design and operation of high-speed machinery a complex and exacting task. Balancing is the only method available to tame these excitation forces. [Pg.192]

May be appropriate if detailed information is required or if it is the only method due to a paucity of published data... [Pg.120]

The only method to determine the actual system performance is to carry out measurements. The questions to be answered are What should be measured How and when How should the results be interpreted Some of the answers to these questions are found in the following sections. [Pg.1119]

This is the only method that matches specific policies with specific procedures, other than numbering each policy. Note that this is not practical for policies that are implemented through many procedures. [Pg.168]

This is not the only method of forming tetrazo-compounds. Each amino-group of a diamine may be diazotised and coupled. Benzidine and its homologues, which ha e been utilised in this way, have a special value for the cotton dyer, as the shades produced are not only ery biilliant, but, unlike the maiorily of... [Pg.290]

Direct emission measurements involve the direct measurement of emission rates from specific sources. Direct emission measurements provide tlie data for emission factor and engineering calculations. This is tlie only method tliat provides emission rates for a given source for a given set of conditions. [Pg.312]

A further stepwise synthesis of this type, in which 2-bromomethyl-3-nitropyridine (105) was the starting material, is the only method so far reported which directly produces pyrido[3,2-d]pyrimidines without nuclear oxygen substituents (106). ... [Pg.173]

This chiral modifier provides one of the only methods for selective cyclopropa-nation of substrates which are not simple, allylic alcohols. In contrast to the catalytic methods which will be discussed in the following section, the dioxaborolane has been shown to be effective in the cyclopropanation of a number of allylic ethers [67]. This method has also been extended to systems where the double... [Pg.119]

The local pntctice, which iB at present the only method by which the oil is ar.lntcled from the stems, leaves, add dowers, is that of direct firing of the still, steam distUlation having oolv been tried aB an cx-... [Pg.82]

The deceriDinatioii oI the anlhraDilio acid esters is of importaoce in iheesbODiial oils Ot this froup which contalo it. The only method of any value is that [Pg.428]


See other pages where Only Methods is mentioned: [Pg.200]    [Pg.2332]    [Pg.2333]    [Pg.2333]    [Pg.2334]    [Pg.350]    [Pg.121]    [Pg.180]    [Pg.402]    [Pg.321]    [Pg.538]    [Pg.344]    [Pg.391]    [Pg.29]    [Pg.6]    [Pg.7]    [Pg.35]    [Pg.371]    [Pg.1104]    [Pg.17]    [Pg.219]    [Pg.313]    [Pg.300]    [Pg.142]   


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Polarography - Methods that Electrolyze Electroactive Species Only Partially

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