Other General Works

In addition to complete histories of the science, several other types of general works may be noted. First, there are several volumes of collected essays that deal, mainly or exclusively, with the history of chemistry. An example of these is the published proceedings of the Symposium on Alchemy, Chemistry and Pharmacy , held during the International Congress of History of Science at Liege in 1997.28 There is also a volume of essays on the history of chemistry in the multi-volume Italian publication, Storia della scienza.29 The five-year European Science Foundation Programme, The Evolution of Chemistry in Europe, 1789-1939 ,30 which was launched in 1993, has resulted in a number of collections of essays on Lavoisier,31 on aspects of the chemical industry,32-35 on chemical textbooks,36 and on chemical education and institutions.37-39 

Furthermore, there is a series of reprints of original papers that in some cases originated well before 1985. They are usually unedited, often with the original pagination. Nevertheless, the Variorum series, in particular, provides a useful way to access and store such material. A collection by Allen Debus relates mainly to chemistry in its early phases40 and is a highly authoritative introduction to such matters. Debus has also recently edited a collection of classic articles on alchemy and early chemistry reprinted from Ambix, the Journal of the Society for the History of Alchemy and Chemistry.41 Another volume in the Variorum series relates to a later period and 

Secondly, there are books that cover the history of chemistry in particular places. The development of chemical science in modem China is the theme of one recent book that is probably the only source in the West of such information.44 Setting a new trail in analysis of national trends was the multi-authored book Chemistry in America 1876-1976.45 This presented a vast mass of empirical data about most conceivable aspects of American chemistry vocational, professional, educational and industrial. Like the History of Chemistry by Partington, to which it bears a curious resemblance in its fact-collecting skills and deadpan presentation, it is unlikely to be replaced for a long time. As will be seen in subsequent chapters there are many smaller studies available of aspects of chemistry in individual countries or regions. One of general interest is a discussion on chemistry in 19th-century Baden,46 while another localizes chemistry to Essex and East London.47 

A different kind of general treatment relates to source materials. It is very important, though often quite difficult, to know just what is available in the secondary literature. The best historical works have either full literary references in footnotes, or separate bibliographies or both. To some extent, it is hoped that the present book will meet that need, but other assistance is available. For example, a book published in 

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A connnon feature of all mass spectrometers is the need to generate ions. Over the years a variety of ion sources have been developed. The physical chemistry and chemical physics communities have generally worked on gaseous and/or relatively volatile samples and thus have relied extensively on the two traditional ionization methods, electron ionization (El) and photoionization (PI). Other ionization sources, developed principally for analytical work, have recently started to be used in physical chemistry research. These include fast-atom bombardment (FAB), matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ES). 

Process Description Gas-separation membranes separate gases from other gases. Some gas filters, which remove hquids or sohds from gases, are microfiltration membranes. Gas membranes generally work because individual gases differ in their solubility and diffusivity through nonporous polymers. A few membranes operate by sieving, Knudsen flow, or chemical complexation. 

In general, the higher the residual or applied metal stress, the more severe the corrosion at a given acidic pH. This explains why many heat exchanger tube ends are often attacked so severely (Fig. 7.1). Tube ends that have been rolled or welded often contain high residual stress. Further, crevices are sometimes present in which acidic species may concentrate (see Chap. 2, Crevice Corrosion ). Screens, rolled sheet metal, and other highly worked metals (not stress relieved) are also prone to attack. 

One is that there may be significant replication of information between the components in a distributed system, for both performance and reliability reasons. A component generally works with others (including people) to support a particular business-level action (or use case), an object generally represents a business concept. These two process-biased and object-biased views give rise to separate tiers in many designs. 

The use of a volatile solvent, e.g., pentane, was not explored because of inherent limitations. Concentration of such extracts was not possible because of the volatility of the sample components. Therefore the maximum concentration factor that could have been achieved was limited by the partition coefficients of the compounds into the solvent used in the extraction. For most compounds this factor was estimated to be about 10 1. Furthermore, with CRMS and other general detectors, the solvent masking problem would still preclude observation of many compounds. Therefore, the method would be limited to detectors that are not responsive to the solvent used in the extraction. Recent work (3.4,5) has indicated that extraction with a volatile solvent is a viable approach for the analysis of a small set of compounds, e.g., the trihalomethanes, with an electron capture detector in drinking water samples where concentration factors of 10 1 or less are acceptable. 

Obviously, graphical techniques are equally important in the study of electron momentum densities. Coulson [2,4] made the pioneering effort in this direction. Other early work was published by Henneker and Cade [305] Epstein and Lipscomb [306-308] Kaijser, Lindner, and coworkers [309-311] Tanner and Epstein [312] and Tawil and Langhoff [313,314]. A synthesis of these studies was made by Epstein and Tanner [13], who abstracted some principles that they hoped would be generally applicable to chemical bonding. One of their abstractions pinned down an observation about the anisotropy of n(p) that had been made in several of the earlier studies. Epstein and Tanner called it the bond directional principle, and they stated it as follows [13] ... 

This coupling means that there is no population decay to the bath and the decoherence is only via the phase. In other pioneering works [39-41], off-diagonal coupling to a Lorentzian bath was considered within the RWA. The Hamiltonians in all of these works should be contrasted with the more general Hamiltonians (4.18), which account for both dephasing and decay into arbitrary baths, without the RWA. 

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