Historical context

In this section, the historical context for Eq. (2) is formulated, the concept of signal entropy is discussed, and a solution for Eq. (2) is shown. The repeated application of Eq. (2) to organometallic and homogeneous catalytic systems is shown. 

Modern pure component spectral reconstruction from multi-component spectroscopic data has its origins in a 1973 paper by Lawton and Sylvester [75] in which a known two component system was studied, and the pure component spectra were determined. The term curve resolution became intimately associated with pure component spectral reconstruction in the chemometrics literature [76]. 

A number of more sophisticated curve resolution procedures for multi-component mixtures have been developed over the years. The most well-known of these procedures are IPCA [77], SIMPLISMA [78] and OPA-ALS [79]. All rely on an a priori estimate of the number of observable species present, most if not all rely on the concept of a pure wavelength i. e. a spectral window where only one component is present, and all have difficulties with trace components i. e. components whose spectral features are embedded in the signal noise. In practice, both the prior estimate of the number of observable species present and the need for pure wavelengths are very serious restrictions, especially for catalytic systems where so many species are simultaneously present.  

With the ability to detect and resolve the C-2 proton resonances of histidine residues in protein NMR experiments came the development of NMR-based methods to study the microenvironment and protonation state of histidine residues in proteins. In one strategy, the pH dependence of the chemical shifts observed for either the C-2 or C-4 protons in the imidazole side chain of histidine residues in protein NMR experiments is detamined the data in the resulting titration curve are used to determine the value of histidine residues in proteins [9,10,12]. Over the decades since its first use in the late 1960s, the earlier NMR strategy has become the method of choice for measuring the pK values of histidine residues in proteins. Such NMR measurements of histidine p T values in 

Acetic acid is an important bulk commodity chemical, with world annual production capacity of 9 million tonnes. Its principal use ( 40%) is in the manufacture of vinyl acetate, a monomer of great importance in the 

Industrial routes to acetic acid have included oxidation of ethanol derived from fermentation, hydrolysis of acetylene, and the oxidation of hydrocarbons such as butane or naphtha. In the late 1950s, the development of the Wacker process (a PdCl2/CuCT-catalyzed oxidation of ethylene) provided a route to acetaldehyde, which could be converted to acetic acid by subsequent oxidation. 

The production of acetic acid by carbonylation of methanol (Equation (1)) can also be traced back to the 1950s when Reppe and coworkers at BASF developed a cobalt iodide catalyst that was effective for this reaction at relatively high temperatures and pressures 250 °C, 600 bar) [1,2]. 

The process based on the cobalt-catalyzed reaction was commercialized by BASF [3,4] but proved not to be so selective as subsequent processes, with an acetic acid yield of 90% (based on methanol feedstock) and 70% (based on CO). The major organic by-products were higher alcohols, aldehydes, and carboxylic acids that required demanding and expensive separation procedures to give acetic acid of sufficient purity. 

The process involving the rhodium/iodide combination was operated by other companies under license from Monsanto, including BP Chemicals and Hoechst-Celanese. In 1986, BP Chemicals acquired the licensing rights 

Materials define the face of society. Initially, since prehistoric times - and to this day - materials were selected amongst those available in nature. These included, besides stones and metals, basic ingredients obtained from plants, crops, and animals in the form of, for example, wood, flax, wool, and leather. Materials use was a skills-based activity perfected by artists and guild-members handed from one generation to the next. 

By the late 19th and early 20th century, chemists discovered and developed a new class of synthetically made materials now known as plastics. In the second half of the 20th century, the perceived abundance of petroleum as cheap feedstock led to an exponential growth through process engineering scale up, establishing plastics as an unsurpassed multipurpose material. 

Over these past 150 years, natural and synthetic materials use became much more founded on knowledge of the underlying physical principles. The evermore sophisticated analytical tools that could probe the molecular world provided insight into the hierarchies of organization from the atoms and molecules up to the macroscopic scale of materials. It became clear that there is more to materials than just innovative molecular synthesis. 

The essential realization in this spontaneous ordering process is the importance of noncovalent bonding interaction between molecules, that is, supramolecular chemistry. These conformation-specific interactions are governed by weak forces including hydrogen bonding, metal coordination, van der Waals forces, pi-pi interactions, and electrostatic Coulombic effects. The cooperative action of multiple noncovalent interaction forces is precisely the path nature takes to produce shape and form. 

The search for connection between shape, structure, and function was posed by D Arcy Thompson in his book On Growth and Form first published in 1917 (Thompson, 1992). His book lets one reflect that complex forms or shapes in nature are not solely a consequence of Darwinian natural selection. They can be purely explained on the basis of geometry, physics, mathematics, and engineering and are guided by underlying physicochemical principles that drive organization of molecules to higher order structures (Ball, 1999,2004). 

The first application of the QSSA is usually attributed to Bodenstein (Bodenstein 1913 Bodenstein and Lutkemeyer 1924), but Chapman and Underhill (1913) and Semenov (1939, 1943) were also early users of the technique. Further pioneers of the application of the QSSA are Michaelis and Menten (1913) and Briggs and Haldane (1925). The history of the application of the QSSA can be divided into three periods (Turanyi et al. 1993b). In the early period (1913-1960), accurate experimental data for various applications were obtained and compared with solutions of simple kinetic systems of differential equations that were formulated to model the experimental behaviour. Due to the limited availability of computer power during this time, the kinetic DDEs had to be solved analytically and using the QSSA helped to convert the systems into an analytically solvable form. 

From the 1960s onwards, computers became available for many researchers, but the stiff systems of DDEs that describe many kinetics applications often could not be simulated using available computer codes during this early period of numerical analysis. By applying the QSSA, the stiff systems of ODEs could be converted to non-stiff ones (Snow 1966 Blouza et al. 2000), and numerical solutions to these ODEs could be obtained using traditional ODE solvers. 

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You will come across numerous examples of qualitative and quantitative methods in this text, most of which are routine examples of chemical analysis. It is important to remember, however, that nonroutine problems prompted analytical chemists to develop these methods. Whenever possible, we will try to place these methods in their appropriate historical context. In addition, examples of current research problems in analytical chemistry are scattered throughout the text. 

Dating. The useflilness of dating techniques in the study of art objects, either for authentication purposes or in the evaluation of their historical context, is self evident (41,42). 

The paper is organized as follows. First the problem will be stated in a historical context. Subsequently, the matrix elements for electromigration and the residual... 

Traditionally, companies have sought to acquire competitive advantage over their rivals through their choice of location. In a historical context, firms tended to establish their factories for reasons of economic geography, e.g. ... 

Enzyme-mediated chiral sulfoxidation has been reviewed comprehensively in historical context [188-191]. The biotransformation can be mediated by cytochrome P-450 and flavin-dependent MOs, peroxidases, and haloperoxidases. Owing to limited stability and troublesome protein isolation, a majority of biotransformations were reported using whole-cells or crude preparations. In particular, fungi have been identified as valuable sources of such biocatalysts and the catalytic entities have not been fully identified in all cases. 

Arguments against this rather simple way of proceeding can be based on the fact that the histoiy of chemistiy is simplified too far in order to produce suitable teaching material. Scientific developments are ripped out of their historical context and sometimes rudely simplified. Other concepts, like the historical problem-centred... 

This section will provide details of recent efforts to polymerize phosphaalkenes. It will begin with an introduction to the factors that must be considered when attempting to polymerize P=C bonds. In addition, a historical context will be provided since, perhaps ironically, it was so-called polymerization reactions that plagued early efforts to prepare compounds possessing heavier element multiple bonds. Finally, it will close with the first successful polymerization of a P=C bond to give poly(methylenephosphine)s. 

The form of this review, which is presented in an historical context, attempts to illustrate the evolution of ideas and opinions on the subject matter up to the present day. 

So far, we have shown where the signal comes from, but how do we measure it There are two main technologies continuous wave (CW) and pulsed Fourier transform (FT). CW is the technology used in older systems and is becoming hard to find these days. (We only include it for the sake of historical context and because it is perhaps the easier technology to explain). FT systems offer many advantages over CW and they are used for all high field instruments. 

The designs of various commercial Fischer-Tropsch refineries have been explored to gain insight into the collective wisdom of many Fischer-Tropsch syncrude refiners. These are the lessons from the past. Some of these insights are bounded by historical context and should be interpreted as such. Nevertheless, there are some points of learning valid for Fischer-Tropsch refining in general ... 

Some synonyms in the Alphabetical index are followed by bracketed notations. These notations provide additional clarifying information about the entry such as composition, modifications to the agents (e.g., thickened, dusty, binary), or a note for historical context. For example, "White Star" was a gas blend that was employed by the British in World War I consisting of 50% phosgene and 50% chlorine. The entry appears as ... 

Moore, Golden Cities, pp. 227-261 Alan Nadel, Containment Culture American Narratives, Postmodernism, and the Atomic Age (Durham Duke University Press, 1995), pp. 90-116. On the racial dynamics of American involvement in the Middle East, see also Soheir A. Morsy, Beyond the Honorary White Classification of Egyptians Societal Identity in Historical Context, in Gregory and Senjak, Race, pp. 175-198. 

Before deseribing the seope of the study, it is important to understand the historical context in whieh Hateh-Waxman arose. Moreover, the generie approval process Hatch-Waxman implemented demands an understanding of the interaction of the patent system and the regulatory structure governing the approval of brand-name drugs. 

To take a stand on one side of the theory/practice debate, or even to attempt to say what alchemy was in a historical context, is already to be... 

IMINO SUGARS AND GLYCOSYL HYDROLASES HISTORICAL CONTEXT, CURRENT ASPECTS, EMERGING TRENDS... 

While these principles may form much of the foundation of toxicology, when it comes to any specific substance there is likely to be controversy. Disagreement may arise on the relative importance of any one of these principles while trying to evaluate implications for public health. Exploring these principles is an essential first step before examining their application to any specific substance. This chapter will explore some of the details and issues surrounding these principles, but first it is appropriate to put them in historical context. 

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