Alternative methods for

An interesting alternative method for formulating f/(jt) was proposed in 1929 by de Boer and Zwikker [80], who suggested that the adsorption of nonpolar molecules be explained by assuming that the polar adsorbent surface induces dipoles in the first adsorbed layer and that these in turn induce dipoles in the next layer, and so on. As shown in Section VI-8, this approach leads to... 

Satellite transition MAS NMR provides an alternative method for detennining the interactions. The intensity envelope of the spimiing sidebands are dominated by site A2 (using the crystal structure nomenclature) which has the smallest Cq, resulting in the intensity for the transitions of this site being spread over the smallest... 

An alternative method for the complete removal of bromine consists in passing the hvdrogen bromide through a solution of phenol in dry carbon tetrachloride. 

An alternative method for ascertaining the end of the reaction, which does not involve the removal of the cover, is to conduct the exit gas through an empty wash bottle (to eict as a trap in case of sucking back ) and then collect a sample in a test-tube over water. If an inflammable gas (hydrogen) is absent, the reaction may be considered complete. Under no circumstances should the reaction be stopped until all the sodium has completely reacted too early arrest of the reaction may result in the product containing sodium hydride, which appears to be partially responsible for the explosive properties of the impure substance ... 

An alternative method for naming the size of the joint, which is sometimes used by manufacturers, consists in assigning a number to the joint diameter at the wide end, thus —... 

An alternative method for isolating the n-butyl ether utilises the fact that n-butyl alcohol is soluble in saturated calcium chloride solution whilst n-butyl ether is slightly soluble. Cool the reaction mixture in ice and transfer to a separatory fimnel. Wash cautiously with 100 ml. of 2-5-3N sodium hydroxide solution the washings should be alkaline to litmus. Then wash with 30 ml. of water, followed by 30 ml. of saturated calcium chloride solution. Dry with 2-3 g. of anhydrous calcium chloride, filter and distil. Collect the di-n-butyl ether at 139-142°. The yield is 20 g. 

Pimelic acid. This may be prepared from 1 5-peiitanediol or tetra-hydropyran, through the dibromide (Sections 111,35 and 111,37) and dinitrile exactly as described for Suberic Acid. An alternative method for the preparation of 1 5-dibromopentane, together with full details of the subsequent steps, is given in the following Section. 

Triphenylchloromethane (C3Hj)3CCl is readily hydrolysed by warm water to triphenylcarbinol, thus providing an alternative method for the preparation of the latter. The former is conveniently obtained by the reaction between carbon tetrachloride and benzene in the presence of anhydrous aluminium ehloride ... 

Section 21 9 Michael addition of the enolate ions derived from ethyl acetoacetate and diethyl malonate provides an alternative method for preparing their a alkyl derivatives... 

Alternative methods for its generation have made it possible to use benzyne as an intermediate m a number of synthetic applications One such method involves treating o bromofluorobenzene with magnesium usually m tetrahydrofuran as the solvent... 

In an alternative method, the senior component is regarded as substituted by RN=N—, this group R being named as a radical. Thus 2-(7-phenylazo-2-naphthylazo)anthracene is the name by this alternative method for the compound named anthracene-2-azo-2 -naphthalene-7 -azobenzene. 

An alternative method for expressing the attenuation of electromagnetic radiation is absorbance. A, which is defined as... 

The phenomena we discuss, phase separation and osmotic pressure, are developed with particular attention to their applications in polymer characterization. Phase separation can be used to fractionate poly disperse polymer specimens into samples in which the molecular weight distribution is more narrow. Osmostic pressure experiments can be used to provide absolute values for the number average molecular weight of a polymer. Alternative methods for both fractionation and molecular weight determination exist, but the methods discussed in this chapter occupy a place of prominence among the alternatives, both historically and in contemporary practice. 

An alternative method for the analysis of permanganate is the use of conventional iodometric methods (177) where excess potassium iodide is added to a solution of permanganate under acidic conditions. The Hberated iodide is then titrated with standard thiosulfate solution using starch as an indicator. 

The estimation of alkoxy groups is not such a simple task. One method (26,68) involves hydrolysis and oxidation of the Hberated alcohol with excess standard potassium dichromate solution. The excess may then be estimated iodometrically. This method is suitable only for methoxides, ethoxides, and isopropoxides quantitative conversion to carbon dioxide, acetic acid, and acetone, respectively, takes place. An alternative method for ethoxides is oxidation followed by distillation, and titration of the Hberated acetic acid. 

Because the Corey synthesis has been extensively used in prostaglandin research, improvements on the various steps in the procedure have been made. These variations include improved procedures for the preparation of norbomenone (24), alternative methods for the resolution of acid (26), stereoselective preparations of (26), improved procedures for the deiodination of iodolactone (27), alternative methods for the synthesis of Corey aldehyde (29) or its equivalent, and improved procedures for the stereoselective reduction of enone (30) (108—168). For example, a catalytic enantioselective Diels-Alder reaction has been used in a highly efficient synthesis of key intermediate (24) in 92% ee (169). 

Chemical Vapor Deposition. Chemical vapor deposition (CVD) of siHcon dioxide from tetraethoxysilane assisted by the presence of oxygen and a plasma is an important technology for the deposition of pure and modified dielectrics for microelectronics (61). An alternative method for the deposition of siHcon dioxide utili2es di-/-butoxydiacetoxysilane (62). 

Alternatives to the methyl chloride dkect process have been reviewed (31). Processes to make phenyl and ethyl siUcones have employed dkect-process chemistry. Phenyl chloride has been used in place of methyl chloride to make phenylchlorosilanes (15). In addition, phenylchlorosilanes are produced by the reaction of benzene, HSiCl, and BCl (17,31). EthylsiUcones have been made primarily in the CIS, where the dkect process is carried out with ethyl chloride in place of methyl chloride (32). Vinyl chloride can also be used in the dkect process to produce vinylchlorosilanes (31). Alternative methods for making vinylchlorosilanes include reaction of vinyl chloride with HSiCl or the platinum-catalyzed hydrosilylation of acetjdene with HSiCl. ... 

Efforts toward producing synthetic steroids, particularly cortisol, expanded during World War II to enable researchers to explore the possibiUty of medicinal appHcations of corticosteroids. In 1948, the discovery that cortisone dramatically alleviates the symptoms of arthritis led to intensive research on the antiinflammatory properties of corticosteroids. The development of partial and total syntheses for the commercial preparation of cortisone, alternative methods for producing cortisone, and the search for more potent antiinflammatory analogues gready stimulated both academic and industrial steroid research. 

An alternative method for measuring air permeabiUty is based on measuring differential pressure when a constant rate of air flow passes through the fabric. In this case, air resistance is reported in typical units of kPa-s/m. 

In the olivanic acid series of carbapenems the ( )-acetamidoethenyl grouping can be isomerised to the (Z)-isomer (19) (22) and reaction with hypobromous acid provides a bromohydrin that fragments to give a thiol of type (20) when R = H, SO H, or COCH. The thiol is not isolated but can react to provide new alkyl or alkenyl C-2 substituents (28). In the case of the nonsulfated olivanic acids, inversion of the stereochemistry at the 8(3)-hydroxyl group by way of a Mitsunobu reaction affords an entry to the 8(R)-thienamycin series (29). An alternative method for introducing new sulfur substituents makes use of a displacement reaction of a carbapenem (3)-oxide with a thiol (30). Microbial deacylation of the acylamino group in PS-5 (5) has... 

Fig. 5. An alternative method for the formation of the penem ring where R = OCOCH2CCI25 Si(CH2)2, or and R" = CH2CCI25 or...

Alternate methods for nonhydrocarbon organics are the first order method of Lydersen with an average error of 9 K although the method of Ambrose is considerably better for alcohols and ketones. 

An alternate method for gas diffiisivity of binary gas mixtures at low pressures is the method of Hirschfelder et al. The method requires several molecular parameters and, when evaluated, gives an average absolute error of about 10 percent. The method is discussed in detail in the Data Vrediction Manual. 

An alternate method for binary concentrated liquid systems where activity coefficients are not available or estimable is the method of Leffler and Cullinan previously given in Eq. (2-156). Absolute errors average 25 percent. 

An alternate method for flash point prediction is the method of Gmehling and Rasmussen and depends on the lower flammabihty limit (discussed later). Vapor pressure as a function of temperature is also required. The method is generally not as accurate as the preceding method as flammability limit errors are propagated. The authors have also extended the method to defined mixtures of organics. 

The transition to turbulent flow begins at Re R in the range of 2,000 to 2,500 (Metzuer and Reed, AIChE J., 1, 434 [1955]). For Bingham plastic materials, K and n must be evaluated for the condition in question in order to determine Re R and establish whether the flow is laminar. An alternative method for Bingham plastics is by Hanks (Hanks, AIChE J., 9, 306 [1963] 14, 691 [1968] Hanks and Pratt, Soc. Petrol. Engrs. J., 7, 342 [1967] and Govier and Aziz, pp. 213-215). The transition from laminar to turbulent flow is influenced by viscoelastic properties (Metzuer and Park, J. Fluid Mech., 20, 291 [1964]) with the critical value of Re R increased to beyond 10,000 for some materials. 

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