Historical developments

The development of present chemical labeling has evolved principally during the last fifty years. Precautionary labeling in the United States really began in 1927 with the passage of the Federal Caustic Poison Act and the attendant regulations by the Food and Drug Administration. Currently, the Federal 

Hazardous Substances Act as amended supercedes the earlier legislation this Act is administered by the Consumer Products Safety Commission at present. Other Acts also include precautionary labeling provisions, for example the Federal Insecticide, Fungicide and Rodenticide Act, administered by the Environmental Protection Agency. The Occupational Safety and Health Act, administered by the Occupational Safety and Health Administration contains provisions for precautionary labeling. Other label requirements of principal interest to the chemical industry are also contained in the Resource Conservation and Recovery Act, The Toxic Substance Control Act, and the Transportation Act. 

The principles from the LAPI Manual were also applied in the development of State and Federal regulations for precautionary labeling. Several states, perhaps a dozen, have adopted the LAPI Guide as a State standard. New Jersey s Safety Notice 2 is one example. 

Scientific development usually comes about in a somewhat orderly fashion. The collection of facts by means of many carefully designed experiments is followed by an attempt to explain and correlate all facts with a suitable theory. 

It must be remembered that, unlike facts, theories can and do often change as more information becomes available. The discussions that follow in this chapter and the next are good examples of how theories are modified or even at times completely discarded in order to accommodate new experimental 

Tassaert s experimental observations could not be explained on the basis of the chemical theory available at that time. It was necessary to understand how C0CI3 and NH3, each a stable compound of presumably saturated valence, could combine to make yet another very stable compound. That they could so combine was a puzzle to chemists and a stimulus to further research, but the answer was not to be found until approximately 100 years later. During that time many such compounds were prepared and their properties studied. Several theories were proposed only to be discarded because they were inadequate to explain subsequent experimental data. 

The preparation of metal complexes generally involves the reaction between a salt and some other molecule or ion (Chapter 4). Much of the early work was done with ammonia, and the resulting complexes were, and are, known as metal ammines. It was also found that anions such as CN, NO2, NCS, and Cl form metal complexes. Many compounds were prepared from these anions, and at first each was named after the chemist who originally prepared it (Table 1.1). Some of these names are still used, but it soon become apparent that the system of nomenclature was not satisfactory. 

Since many of the compounds are colored, the next scheme was to name compounds on the basis of color (Table 1.2). The reason behind this scheme was that colors of chloroammine complexes of cobalt(lll) and chromium(iii) containing the same number of ammonia molecules were found to be very 

Historical Development. In this category of FT spectrometer the complete time-evolution of the IR transient is digitized whilst the interferometric mirror is held stationary at each sampling point. The transient can be initiated repeatedly and signal averaged to achieve an adequate SNR. The 

In this chapter, we review FBDD on the historical and operational level. There are many different techniques which are now classified as fragment based, and we attempt to explain how they can be applied on a case-by-case basis. 

FIGURE 11.2 Binding modes in p-lactamase of (a) 1 (white), along with 2 (cyan) and 3 (yellow) in a tunnel carboxylate site, (b) overlay of 1-4, and (c) 1, along with 2 and 4 (yellow) in a distal carboxylate binding site. Source Reprinted with permission from Ref. [11] (Nature Publishing Group). 

FIGURE 11.3 Binding of 1 and 5 (purple) in (3-lactamase. Source Reprinted with permission from Ref. [11] (Nature Publishing Group). 

One powerful tool frequently used to rank hits coming from any screening campaign is ligand efficiency (LE).  

Once a fragment has been detected to bind to the target protein, the magnitnde of its binding must be established. 

The invention of the dropping mercury electrode in 1922 by Heyrovsky [1] led to the development and the extensive use of polaro-graphy, which must be considered to be the first linear sweep voltammetry method. In the period from 1947 to 1959, the theory and practice of voltammetry at solid stationary electrodes were developed [2—20]. Due to the significant differences in the mode of mass transport to the two types of electrode, the response and the range of utility differ markedly. Thus, the techniques are sufficiently different that they must be treated separately. The generally accepted convention is that polaro-graphy refers to measurements at the dropping mercury electrode, while measurements at stationary electrodes are referred to as linear sweep voltammetry (LSV). 

Only measurements at stationary electrodes will be considered in this chapter. Leading references to the vast literature dealing with polaro-graphy can be found in recent books [21, 22]. 

In order to circumvent the limited possibilities of the original Volta pile, the following period saw the development of other battery systems in which special oxidizers were introduced. In 1836, J. F. Daniell (1796-1845) developed a cell with an oxidizer in the form of copper ions in a copper sulfate solution. Cells with the use of nitric acid as oxidizer were developed in 1838 by W. R. Grove (1811-1896) and in 1841 by R. Bunsen (1811-1899). Cells containing sodium bichromate dissolved in sulfuric acid were developed in 1843 by Ch. Poggendorff (1824-1876) and in 1856 by Grenet. 

The development of IRMs is strongly connected with the determination of atomic weights of the elements, because measurement techniques and procedures have primarily been developed for atomic weight determinations. A concise historical review of the determination of atomic weights was given by De Laeter et al. in the lUPAC technical report Atomic weights of the elements review 2000 [36]. This review also hsts the latest lUPAC values for the isotopic composition of the elements. A later publication from 2005 presents the same data in a different form [57]. 

Radioactive IRMs are not considered separately. A list of the radioactive IRMs available is displayed in Table 6.3 to provide the reader with an overview. So far as IDMS applications or isotopic variations in Nature are concerned, they involve stable materials. IRMs for nuclear applications, especially those from IRMM, are of excellent quality and fulfill the needs of the users. Therefore, there is no strong need at present for further or better IRMs for use in this context. 

Nearly all existing IRMs are searchable via two databases. The COMAR database is operated by BAM and lists several thousand CRMs including IRMs [79]. The GeoReM database lists a large number of materials including IRMs, but also materials that do not fulfill the requirements of an IRM (see the next section) [80]. 

The data attributed to the specific materials are based on a compilation of the existing literature, which is not complete in every case BAM-I012 is a good example of this, because the basic reference [47] is not given in the database. 

The condensation reaction between carboxylic acid and alcohol to form an ester and water is a fundamental chemical reaction, and has been known at least from when the term organic chemistry was coined in the early nineteenth century. From the mid- to late-nineteenth century, studies were carried out on the reactions of compounds containing more than one acid group with compounds containing more than one hydroxyl group. These studies produced the first polyester resins, and lead to the development in the early twentieth century of various thermoset polymers such as the alkyd resins. 

Attempts had been made to synthesise polyesters based on phthalic acid as the diacid component, but these products were amorphous, had low softening points, and were rapidly attacked by organic solvents and acids and bases. Research into polyesters made by the reaction of terephthalic acid (or esters thereof) with aliphatic diols, led to the discovery of polyesters of high commercial value poly(alkylene terephthalate)s [4]. This pairing of diols with terephthalic acid eventually led to the most commercially successful aromatic polyesters, but other synthetic pathways were also investigated towards such products in the early days of polyester development. These included the self-condensation of hydroxy acids of the structure -H0-R-Ph-C02H, where R-OH is para to the acid group and R is -(CH2)- or -(CH2)2- [5], and reactions of aliphatic diacids with 1,4-dihydroxy benzene and similar aromatic diols [6, 7]. Also synthesised about the same time were polyesters based on C2-Cg aliphatic diols and any of the isomeric naphthalene dicarboxylic acids [8]. 

Research was carried out in commercial laboratories into wholly aromatic polyesters, especially those based on the self-condensation of p-hydroxybenzoic acid, to produce materials of higher potential strength and stability [9-11]. It was found that such homopolymers were extremely refractory materials, and could not be processed by normal techniques used for standard thermoplastics. 

Further work on aromatic polyesters centred on the condensation of aromatic diacids and dihydric phenols [12], and the condensation of non-fused polynuclear aromatic diacids with non-fused polyaromatic phenols [13,14] which were expected to be less refractory than the prior art aromatic polyesters. Neither approach provided the desired combination of extreme physical properties with processability. 

Research centred on copolymers of terephthalic acid, isophthalic acid, bisphenols, and p-hydroxybenzoic acid to provide materials with the 

The second part of this book is devoted to current and potential applications of adhesive materials in construction. Chapter 6 deals with both the repair and the strengthening of concrete structures, covering applications ranging from non-structural patch repairs and resin overlays to externally bonded steel plate reinforcement. The theme of repair and strengthening is extended to applications involving steel, timber and masonry structures. A number of case histories are reviewed and discussed with reference to the successes and failures, and the results of allied research work are presented. In Chapter 7 a number of applications of adhesives in new construction are described, and specific examples are given. The final chapter. Chapter 8, examines the potential for future developments in adhesive usage. 

The link between the first and the second parts of the book is emphasised throughout in an attempt to connect theory with practice, highlighting some of the problems and identifying methods for overcoming them. 

Over the past four or five decades the natural adhesives have 

It is clearly impossible to identify and to document all of the applications of adhesives in engineering assembly and fabrication. Many uses are, anyway, either of a relatively trivial nature or else do not place great demands on the adhesive material. The following sections review some of the major applications of adhesives in several different engineering sectors, in order to put a number of the general design and process considerations discussed later in the book into perspective. 

The first calculations on a two-electron bond was undertaken by Heitler and London for the H2 molecule and led to what is known as the valence bond approach. While the valence bond approach gained general acceptance in the chemical community, Robert S. Mulliken and others developed the molecular orbital approach for solving the electronic structure problem for molecules. The molecular orbital approach for molecules is the analogue of the atomic orbital approach for atoms. Each electron is subject to the electric field created by the nuclei plus that of the other electrons. Thus, one was led to a Hartree-Fock approach for molecules just as one had been for atoms. The molecular orbitals were written as linear combinations of atomic orbitals (i.e. hydrogen atom type atomic orbitals). The integrals that needed to be calculated presented great difficulty and the computations needed were 

It is worthwhile to briefly discuss the history of investigations into the mechanism of diazotization. Its progression between 1894 and 1958 demonstrates that it may take more than 60 years to correct a false mechanistic interpretation of good experimental results followed by many supporting conclusions. 

A widely significant and crucial investigation of the mechanism of diazotization was made in 1899 by Hantzsch and Schumann widely significant because it was one of the first mechanistic investigations using appropriate methods of organic chemistry - extremely crucial because it influenced all subsequent investigations in the field of diazotization mechanisms until 1958. 

That the reaction appeared to be second-order was confirmed by several groups (see compilation by Zollinger, 1961, p. 25) and all these arguments appear to be based essentially on the views originally developed by Hantzsch. However, Taylor s 

Diazo Chemistry I Aromatic and Heteroaromatic Compounds. By Heinrich Zollinger Copyright 1994 VCH Verlagsgesellschaft mbH ISBN 3-527-29213-6 

Schmid s work marks the start of a change in the way in which the mechanism of diazotization was regarded, although it seems surprising that Schmid did not discuss further the contrast between his result indicating a reaction of third order and Hantzsch s claiming a second-order reaction. The diazotization mechanism in dilute HC1 and HBr will be discussed in Section 3.3. 

32 NaCl-2H20(cr) 47 Na2S04-MgS04-4H20(cr) 62 Na2C037H20(cr) 77 KBH3(S04)4(cr) 

35 CaCl2-6H20(cr) 50 MgS04-12H20(cr) 65 CaC03(cr,vaterite) 80 MgS04-H20(cr) 

37 MgCl2-8H20(cr) 52 CaC03(cr,calcite) 67 KN03(cr) 82 FeS04-H20(cr) 

38 MgCl2-12H20(cr) 53 MgC03(cr) 68 NaN03(cr) 83 FeCl2-6H20(cr) 

39 KMgCl3 6H2 O (cr) 54 MgC03-3H20(cr) 69 HCl-3H20(cr) 84 FeCl2-4H20(cr) 

A true chemical synthesis of specific oligosaccharides had to await the discovery of monosaccharide derivatives that were suitable as starting 

Although sucrose has not been synthesized by strictly chemical means, its synthesis has been accomplished by the use of enzymes from living organisms.86 An enzyme from the bacterium Pseudomonas saccharophila Doudoroff was allowed to act on D-glucose-l-phosphate in the presence of D-fructose. This synthesis gives little information about 

For unpolarized incident radiation, using electrostatic units, 

The total scattering cross section, called the Thomson cross section, 

The unit of length, e2/me1 = 2.82 x 10-13 cm, is called the classical electron radius, because a classical distribution of charge totalling the electronic charge must have a radius of this order for its electrostatic self-energy to be equal to the electronic mass energy. This estimate of the size of an electron is crude, but still the only one available. 

The relativistic Lorentz-Dirac description of the electron is generally accepted to be the ultimate classical description, albeit without Dirac s physical 

The driving force in the search for methods of nitrogen fixation, of course, was to produce fertilizers. In principle there are three ways of breaking the bond of the nitrogen molecule and fixing the element in a compound  

1) To combine the atmospheric elements nitrogen and oxygen directly to form nitric oxides 

3) To use compounds capable of fixing nitrogen in their structure under certain reaction conditions. 

A vast amount of research in all three directions led to commercial processes for each of them the electric arc process, the cyanamid process, and ammonia synthesis, which finally displaced the other two and rendered them obsolete. 

After Berthollet proved in 1784 that ammonia consists of nitrogen and hydrogen and was also able to establish the approximate ratio between these elements, many 

Metal-catalyzed epoxidations with alkyl hydroperoxides show the following characteristic features [12, 13]. 

An alternative mechanism for oxygen transfer was proposed by Mimoun [21-25]. In this mechanism (eq. (11)) initial coordination of the olefin to the metal is followed by its rate-limiting insertion into the metal-oxygen bond giving a pseudocyclic dioxometallocyclopentane (Structure 3). The latter decomposes to the epoxide and the metal alkoxide. 

Evidence in favor of olefin coordination was provided by competition experiments with different olefins using the stable r-butylperoxovanadium(V) complex (Structure 4) as a stoichiometric epoxidizing agent [24]. 

However, the catalytic activity observed with molybdenum porphyrins [27] in epoxidations with TBHP favors the mechanisms involving direct attack of the olefin on the electrophilic oxygen of the alkylperoxometal complex (see earlier). Because of the steric hindrance of the macrocyclic ligand it was considered 

The reaction of efliylene with carbon monoxide in the presence of potassium tet-racyanonickelate(II) can be regarded as the first example of an aqueous polymerization. In a patent filed 1948, Reppe and Magin described the formation of oligomers (n=l, 2) and higher polyketones [Eq. (3)] [19]. Albeit based on the analytical data provided it is unlikely that a true higher-molecular weight polymer was formed without doubt several repeat units were incorporated per product molecule, a mechanistic feature which also applies to polymerization reactions. 

In the 1960s a number of publications on aqueous polymerizations of different monomers appeared. Rinehart et al. and Canale and co-workers independently reported aqueous polymerization of butadiene catalyzed by rhodium salts. Utilizing Rh Cl3 3H2O as a catalyst precursor, semicryslallirie trans-l,4-polybutadiene was obtained stereoselectively [Eq. (4) 99% trans] [20, 21]. 

By comparison, free-radical butadiene polymerization in aqueous emulsion typically yields polymers with 60% trans-incorporated units under similar conditions [22]. Polymer molecular weights of 2.6 x 10 g mol were determined by light scattering [21]. 

A free-radical polymerization mechanism can be excluded on the basis of the polymer microstructure and experiments with radical inhibitors. Rhodium(I)-spe-cies, formed by reduction of Rh salts used as catalyst precursors by butadiene monomer, have been suggested as the active species. The catalyst is stable during the aqueous polymerization for over 30 h [23]. Catalyst activities are moderate with up to ca. 2x10 TO h [24, 25]. By contrast to industrially important free-radical copolymerization, styrene is not incorporated in the rhodium-catalyzed butadiene polymerization [26]. Only scarce data is available regarding the stability and other properties of the polymer dispersions obtained. Precipitation of considerable portions of the polymer has been mentioned at high conversions in butadiene polymerization [23, 27]. 

Under similar conditions as those described by Rinehart for butadiene polymerization, Natta et al. investigated the polymerization of cyclobutene. With low conver- 

The original Lonza synthesis [1, 2] of (d)-(+)-biotin 1 (outlined in Fig. 1) was designed around the critical diastereoselective hydrogenation of the tetrasubstituted double bond in imidazolinone 2 to the desired 3aS,6aR isomer 3. This strategy was a natural consequence of the experience gained with an analogous diastereoselective hydrogenation in the synthesis of an intermediate for the Merck antibiotic thienamycine (see Fig. 2). 

Despite an extensive catalyst screening, the best diastereoselectivity obtained for the conversion 2-3 (Fig. 3) was modest (70 30) and unfortunately could not be significantly improved by variation of the substituents. However, it was adequate for a first generation process, as isolation conditions could be optimized to provide a 58% yield of 3 with less than 1% of the diastereomer 4. 

Once the complete biotin process had been established as technically feasible, the evident weakness of the hydrogenation step was addressed. In fact the original synthesis design involved the hydrogenation of the corresponding thiophe- 

As has already been described in the Introduction, the first electrochemical ESR experiment was performed by Ingram and co-workers [2] who demonstrated the formation of aromatic radical ions in electroreductions. However, the real potential of the joint electrochemical ESR technique was demonstrated first by the work of Maki et al. [3, 4,12-14], They obtained the first solution spectra of electrochemically generated radicals and by doing so performed the first in-situ electrochemical ESR experiment. This was performed in a two-electrode electrolysis cell, the anode being a platinum wire within a 3 mm o.d. capillary tube, the lip of which was positioned centrally, along the axis of a cylindrical cavity. The cathode was separated from the anode by sinters and was outside the ESR cavity. The system 

The in-situ cell was then used by its inventors to investigate the reduction of nitrobenzene [4], o-, m-, and p-dinitrobenzenes [12] and substituted nitro-benzenes [13] in non-aqueous media. 

The success of Adams cell in generating large quantities of relatively long-lived radicals has proved of value to the spectroscopist, but the electrochemist finds that the cell is unsuited for performing experiments where well-defined voltammetric measurements must be made and that the study of 

Finally, it must be pointed out that the Adams cell precluded the measurements of kinetic data. It would be possible, in principle, to open-circuit the working electrode and observe the decay of the radical with time, but the 

Further developments in electrochemical ESR were carried out by electrochemists, who attempted to improve the electrochemical behaviour of the cell whilst maintaining the ability to generate large numbers of radicals. Also, attempts were made to determine the lifetimes of radical intermediates and their kinetic modes of decomposition. The subsequent historical development of electrochemical ESR is shown schematically in Fig. 11. As one can see, two alternative approaches were utilised dependent on whether the working electrode was situated inside or outside the cavity. 

Evolution has taught us that biological systems find or create ways to adapt to exogenous forces or stressors. Natural products are often the result of this 

The history of biphasic homogeneous catalysis starts with Manassen s statement [1]  

This was the starting point of Kimtz s work at Rhone-Poulenc, trying to transfer rhodium catalysts from the organic monophase to the aqueous biphase not by triphenylphosphine monosulfonate (which had been tried by Joo or WiUdnson (4, 8]) but by TPPTS. From 1974 onward, the scope of different reactions using biphasic catalyst systems was tested in laboratory-scale experiments. Among these were 

Copyright 2005 Wiley-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 3-527-30721-4 

For it is one thing to invent a process that is right in principle but a very different thing to introduce it on the industrial scale.  

Because of Ruhrchemie s commitment and status as an important oxo producer, development was primarily driven by product and commercial considerations. It was not until the 1990s that further development became science-driven, including especially all the scientific research work currently being conducted at universities as a result of the successful implementation of the RCH/RP process. 

The first painted objects come from China. Furniture and utensils were covered with a layer of paint in an artistic design. The oldest tradition work dates from around 200 B.C. The lacquer used was the milky juice from the bark of the lacquer tree Rhus vernicifera). This was colored black or red with minerals, and later also with gold dust or gold leaf. 

Problems of environmental pollution also followed from the introduction of solvents. These were recognized by the late 1960s and became the subject of develop- 

Safety and risk management programs have always been an integral part of the process industries. Initially such programs were quite crude and basic, but they have become much more sophisticated as standards have risen and as processes have become more complex. 

People working in the process industries now take it for granted that safety is a value, even when their own organization has a poor safety record—no one ever says, Safety doesn t matter. However, such an attitude was not the norm 200 years ago. In his novel Hard Times, published in the year 1854, Charles Dickens satirically condemned the industriahsts who failed to acknowledge that safety and clean air were values, in and of themselves. 

They [the industrialists] were ruined when they were required to send labouring children to school they were ruined when inspectors were appointed to look into their works they were ruined, when such inspectors considered it doubtful whether they were quite justified in chopping people up with their machinery they were utterly undone, when it was hinted that perhaps they need not always make quite so much smoke... 

The weapon that Dickens and his fellow authors used was satire. This weapon has now fallen out of use—modem professional safety workers rarely attempt the use of irony (although some of what is written in Chapter 3 in the section to do with Warning Flags represents a feeble attempt to follow in Dickens footsteps). 

By the beginning of the twentieth century, the number of industrial accidents had risen to unacceptably high levels. For example, between the years 1870 and 1910, at least 10,(XX) boiler explosions occurred in North America. By the year 1910, the rate of such explosions had reached approximately 1,400 per year. 

Georg Eisner (1980, 1981) explored surgical viscoelastic substance use from the more practical aspects of tissue surface application and space creation. His impressive representations of viscoblockade, -tamponade and viscospatula (Eisner, 1983) are a tribute to his efforts. 

Membrane filters were first commerciafised in 1927 by the Sartorius Company in Germany using the Zigmondy process. Reverse osmosis (RO) was first observed and studied in the 1920s. However, it remained unnoticed until rediscovered by Reid and his co-workers 30 years later. The first practical phenomenon of haemodialysis was demonstrated by Kolff in the 1940s. Membrane milestones are given in Table 1.1. 

Membrane potential TeoreU, Meyer, Sievers 1930s 

Membrane-transport models Kedem, Katachalsky, Lonsdale, Merten, Pusch, Sourirajan 1960-1970 

Spiral-wound membrane element Westmoreland, Bray 1965-1970 

HoUow-fibre RO membrane Mahon, Hoehn and Milford 1965-1970 

Of special note was the use of the electronically nonactivated bromobenzene as electrophile, combined with [ P(o-Tol)3 2PdCl2j as catalyst for the transformation. A clear disadvantage here was the fact that the nucleophile, a tin amide, was not only toxic but also notoriously difficult to prepare [20]. 

Subsequently, this area of research lay almost dormant until Buchwald reported the in situ preparation of tin amides in 1994. Here, Bu3Sn-NEt2 was used as a relay for the formation of tin amides derived from the amine starting materials, through the removal of HNEt2 [23]. 

Based on these contributions and subsequent reports, the reaction is today often referred to as the Buchwald-Hartwig amination, and is considered as a standard fundamental organic reaction. Although a review of the myriad of exciting developments occurring since 1995 is beyond the scope of this chapter, we will nonetheless attempt to provide details of the current state of the art. 

To achieve the required higher capacity, the substrate particles consisted of 55% crosslinked ethylvinylbenzene-divinylbenzene core with a surface area of about 450 g . A polymer containing three carboxyhc groups per unit was applied as 

It is not possible to review here the entire hi.story of chromatography and do justice to all the scientists who have contributed to designing and developing the dozens of major separation techniques based on the principle of chromatog- 

Chromatography is based on phase-equilibrium phenomena. The components of the analyte sample are caused to equilibrate between two pha.ses, a mobile phase and a stationary phase. Because the mobile phase percolates through the stationary phase, rapid mass transfer takes place, and the mobile phase carries the components through the column to a detector. The velocity of this transfer is related to the equilibrium constant. Hence, only compatible combinations of mobile and stationary phases can be used in practice. 

The mobile phase must be a fluid A gas, a dense gas, or a liquid, where the rale of mass transfer through the mobile phase, characterized by the diffusion coefficient, decreases in the order listed. To compensate for this marked decrease, finer and finer particles are used as the mobile pha.se becomes more dense. The practical lack of compressibility of liquids supports this trade-off. since small particles demand higher pressures. However.viscous liquids (e.g.,glycerol,oligomers, or concentrated solutions of polymers) are excluded, because the associated pressure requirements would be unrealistic. 

The stationary phase must be compatible with the mobile phase. Lack of solubility of the stationary phase in the mobile phase and a large inter-facial area between the two phases are the two major requirements. Most adsorbents are applicable to any of the three types of mobile phase, giving rise, for example, to both gas-solid and liquid-solid chromatography. The specific sur- 

While gas-liquid chromatography has become the preferred implementation of gas chromatography because of the excessive adsorption energy associated with gas-solid equilibria, for most compounds but gases, liquid-solid chromatog- 

Classic and Advanced Ceramics From Fundamentals to Applications. Robert B. Heimann 2010 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-32517-7 

A milestone in manufacturing leather was the discovery of the tanning properties of trivalent chrome salts like chrome sulfate at the end of the 19 century. All the tanning agents have been used so that vegetable, synthetic and mineral tanning can be distinguished. 

Tanning has been carried out in pits but currently it is carried out mainly in moving vessels, i.e. drums. Movement supports the tanning process and shortens the time necessary. 

The predominant tanning technique in the world is chrome tannage (about 85%). As a multi-purpose material chrome tanned leather can be transferred to leather with different properties (to different leather types) by further processing. However, a significant quantity of vegetable tanned leather is manufactured, too. Part-tanned chrome-free - often termed wet white - leather is also produced, in small but growing quantity. 

The decomposition of histidine by liver brei was observed independently by Edlbacher and by Gyorgy and Rothler, Edlbacher and 

Urocanic acid has been isolated from the urine of various animals fed L-histidine (see for older references). None was obtained from D-histi-dine. Reports that urocanic acid was excreted following subcutaneous injection of histidine could not be confirmed. Furthermore, the older work has been criticized because of inadequate isolation methods. 

Orally administered urocanic acid is promptly excreted. The urocanic acid obtained in histidine feeding experiments, it was suggested, could have been formed by intestinal bacteria, as certain species have the capacity to convert histidine into urocanic acid.  

The hydrolytic sphtting of urocanic acid by liver extracts was first observed by Sera and Yada, and confirmed by others. The enzyme that causes this decomposition was named urocanase. 

Edlbacher and co-workers - concluded that urocanic acid formation represented a minor pathway in the metabolism of histidine. It was their contention that histidase directly caused the opening of the imidazole ring of histidine to yield the compound with the properties mentioned above. Indirect support for this claim was provided by the observation that urocanic acid, when administered to rabbits, was not easily metabolized, and upon injection into guinea pigs was excreted in the urine practically quantitatively.  

Quantum Mechanics is a set of mathematical rules upon which physical theories are constructed. Applying the rules of quantum mechanics, it is possible to calculate the observables of an isolated physical system, at any instant in time, once the Hamiltonian is known [5]. However, there is no precise prescription for finding a Hamiltonian of a specific system. 

It is correct to state that Quantum Mechanics is the most weU succeeded theory in physics. Since its creation up to nowadays it has been applied to various branches, varying from particle physics to condensed matter, passing through nuclear and atomic physics, astrophysics, etc. The success of quantum mechanics in condensed matter physics has been 

1973 - The possibility of reversible classical computation was demonstrated by Charles Bennett. 

1982 - First proposal of quantum computer presented by Paul Benioff based on 

1984 - Charles Bennett and Gilles Brassard create the quantum cryptography protocol BB84. 

The interaction of light with matter has captured the interest of man over the last two millennia. As early as a.d. 130, Ptolemaeus tabulated the refraction of light for a range of transparent materials, and in 1305, Von Freiburg simulated the structure of the rainbow by using water-filled glass spheres. 

However, Herschel [2] clearly attached great importance to the analysis of light. In a letter to Professor Patrick Wilson, he concludes  

By the beginning of the twentieth century, the nature of the electromagnetic spectrum was much better understood. James Clerk Maxwell had formulated his four equations determining the 

Observationally, little progress had been made. Fraunhofer used a newly produced diffraction grating to resolve the sodium D lines in a Bunsen-bumer flame as early as 1823 and Kirchoff had visually recorded the atomic spectra of many elements by the 1860s. Sadly, lack of suitable detection equipment impeded real progress outside the visible part of the spectrum. 

Coblentz discovered that no two compounds had the same spectrum, even when they had the same complement of elements (e.g., the isomers propan l-ol and propan2-ol). Each compound had a unique fingerprint. However, Coblentz noticed certain patterns in the spectra for example, all compounds with OH groups, be they alcohols or phenols, absorb in the 2.7 /rm region of the spectrum. In this way, many molecular groups were characterized. He also speculated the existence of harmonically related series. Essentially, Coblentz gave chemists a new tool, spectroscopy, where they could obtain some structural information about compounds. 

According to Cady [41], tonrmahne crystals came from Ceylon to Europe in the early 18 century and were foimd to possess a number of remarkable characteristics. Although a relationship between mechanical and electrical behavior had been expected by the scientific community, it could not be demonstrated experimentally for many years. Finally in 1880, the brothers Pierre and Jacques Curie [59,60] discovered the proportionahty of pressure apphed in specific directions and electric charges appearing with op -posed signs on opposed surfaces. The following year, the term piezoelectric effect has been proposed for the observed behavior by Hankel [91]. The prefix 

Brockmann, Theory of Adaptive Fiber Composites, Solid Mechanics and Its Applications 161, 

The decomposition of histidine by liver brei was observed independently by Edlbacher (m ) and by Gyorgy and Rothler 2S8). Edlbacher and coworkers ( 29) demonstrated that histidine was decomposed by liver extracts to NH, formic acid, and a derivative which yidds glutamic acid upon further treatment with alkali. The enzyme caudng this reaction was named histidase and was described as capable of liberating 1 mole of NH from histidine and producii a compound which yielded a second mole of NH on treatment with strong alkali. Histidase activity was shown to occur only in liver and to be present in the livers of all vertebrates tested. Only L-histidine was decomposed. 

The Japanese investigators (234-236, 239) proposed an alternate pathway, namely, that histidine was first deaminated to urocanic acid by an enzyme named by them, histidine deaminase, and the urocanic acid in turn was converted to a product which yielded glutamic and formic acids. 

Two different technological approaches are reflected by this classification. The main problem of low-temperature cells consists in finding efficient electrocatalysts so that the rates of the electrochemical reactions are still satisfactory at low polarization. Since the reaction rates increase with temperature, the role of the electrocatalyst is not so critical in the high-temperature cells. Other problems like corrosion and conductivity of the electrolyte become pertinent for the construction of a practical unit. 

Another classification may be based on the type of electrolyte used in the cells. The following types are under evaluation in different laboratories  

The largest research effort has been put into cells belonging to categories a, c, d, and e of the second classification. Fundamental problems of these cells are discussed in this book. 

The situation changed after the second world war with the publication of the results of Davtyan [20] on solid electrolytes for high-temperature 

The technological aspects of the new approaches towards a practical fuel cell are adequately covered in recent books [3,24,29-34]. In contrast, the emphasis of this book is on the fundamental electrochemical problems of fuel cells. 

Naturally, the first enzyme fixation methods [2] involved physical retention, and it was attempted to preserve, as far as possible, the integrity of the biological system. It was later realized that covalent fixation would prevent enzyme loss, and ensure long-lasting immobilization. The immobilization of enzymes is of prime importance. So long as the enzymes remain active, their immobilization enables repetitive and multiple determination. Conventional enzymatic methods discard the enzyme after each separate sampling. Enzymes are expensive because of the various extraction and purification stages they require, and we can immediately understand the economic interest of the new procedure, and its impact on the cost of sample analysis in automated systems. 

The immobilization of more than one enzyme on a single support was another important step in the development of enzyme sensors [3]. A single enzyme is not always sufficient to transform the substance under study into a substance that is detectable by a transducer. It is often necessary to resort to several enzymes to perform a series of 

A large technological expansion has also occurred in the area of fiber optics. Improvements have been made in the optical quality and mechanical resistance of optical fibers, and they now have many applications in transducers. Optical fibers lend themselves to the construction of biosensors a suitable biological substance is attached to the tip of the fiber and produces an optical signal when it is in contact with the system under study [8]. Optical biosensors exploit a variety of radiation phenomena, for example, absorption, fluorescence, and 

The technique of detection via light absorption [9] exploits results from UV-visible spectrophotometry, especially in the use of monochromatic radiation and a reference system. This requires the presence of at least two fibers, to separate the outward and inward light beams, and so this method is rarely used. In contrast, fluorescence [10] can be measured directly using a single fiber and very low concentrations can be detected. Furthermore, coupling the immobilized enzyme on an optical fiber with a fluorescent cc actor, such as NADH, opens up greater possilnlities. The system is even simpler in the case of bio/chemiluminescence because the reference and excitation beams are obsolete, and the light can be emitted directly to the sensitive component [11]. The excellent quantum yield of bioluminescence also facilitates the detection of low concentrations. 

Hnally, enzyme biosensors can employ thermal [12] or piezoelectric transducers [13], which detect variations in temperature or mass during an enzymatic reaction. Such biosensors have an extremely rapid response. 

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Tracing the historical development of quantum physics, the author describes the baffling and seemingly lawless world of leptons, hadrons, gluons and quarks and provides a lucid and exciting guide for the layman to the world of infinitesimal particles. 

J, Mehra and H, Rechenberg, The Historical Development of Quantum Theory, Springer-Verlag, New York, 1987, Vol. 5, Part 2. 

As a chemist, I should briefly discuss what my field of science is. Here 1 also reflect on its historical development and scope, which help to put in perspective the broad background on which our contemporary chemistry was built, and where my own work fits in. 

An article in the December 1988 issue of the Journal of Chemical Education traces the historical development of Markovnikov s rule In that article Markovnikov s name is spelled Markow nikoff which is the way it appeared in his original pa per written in German... 

There are two problems in the manufacture of PS removal of the heat of polymeriza tion (ca 700 kj /kg (300 Btu/lb)) of styrene polymerized and the simultaneous handling of a partially converted polymer symp with a viscosity of ca 10 mPa(=cP). The latter problem strongly aggravates the former. A wide variety of solutions to these problems have been reported for the four mechanisms described earlier, ie, free radical, anionic, cationic, and Ziegler, several processes can be used. Table 6 summarizes the processes which have been used to implement each mechanism for Hquid-phase systems. Free-radical polymerization of styrenic systems, primarily in solution, is of principal commercial interest. Details of suspension processes, which are declining in importance, are available (208,209), as are descriptions of emulsion processes (210) and summaries of the historical development of styrene polymerization processes (208,211,212). 

Distillation has been practiced in one form or another for centuries. It was of fundamental importance to the alchemists and was in use weU before the time of Christ. The historical development of distillation has been pubHshed (1) as has the history of vapor—Hquid contacting devices (2). 

Essentially, the technology of active carbon fibers is a combination of the technologies for carbon fibers and active carbons summarized above. This section is an outhne of the historical development of ACT. 

The target level assessment process for paper machine halls is the result of long historical development. The performances of installed paper machine hall ventilation systems are measured very often and the results are compared with input data used as the basis for design. As a result of these comparisons corrections are made to the design process as necessary. 

Chapter 2 is a general discnssion of die historical development of DBAs, and an overview of the applicable standards and codes is presented. 

To return to a more historical development the mercuric acetate oxidation of substituted piperidines (77) should be discussed next. This study established that the normal order of hydrogen removal from the aW-carbon is tertiary —C—H > secondary —C—H > primary —C—H, an observation mentioned earlier in this section. The effect of substitution variations in the piperidine series can be summarized as follow s l-mcthyl-2,6-dialkyl and 1-methyl-2,2,6-trialkyl piperidines, as model systems, are oxidized to the corresponding enamines the 1,2-dialkyl and l-methyl-2,5-dialkyl piperidines are oxidized preferentially at the tertiary a-carbon the 1-methyl-2,3-dialkyl piperidines gave not only the enamines formed by oxidation at the tertiary a-carbon but also hydroxylated enamines as found for 1-methyl-decahydroquinoline (48) (62) l-methyl-2,2,6,6-tctraalkyl piperidines and piperidine are resistant to oxidation by aqueous mercuric acetate and... 

F. P. Venable, The Developmeni of ihe Periodic Law, Chemical Publishing Co., Easton. Pa., 1896. This i.s Ihe first general review of periodic tables and has an almost complete colleclion of those published to that lime. J. W. Van Spronsen. The Periodic Syeiem of ihe Chemical Elements, Elsevier. Amsterdam, 1969, 368 pp. An excellent modem account of the historical developments leading up to Mendeleev s table. 

It is also important to realize that chemistry is not a static body of knowledge as defined by the contents of a textbook. Chemistry came from somewhere and is at present heading in various specific directions. It is a living self-stimulating discipline, and we have tried to transmit this sense of growth and excitement by reference to the historical development of the subject when appropriate. The chemistry of the elements is presented in a logical and academically consistent way but is interspersed with additional material which illuminates, exemplifies, extends or otherwise enhances the chemistry being discussed. 

General accounts of prototropic tautomerism have been presented by Ingold and Baker" these include an outline of the historical development of the subject in which heteroaromatic compounds are discussed incidentally, and, therefore, such a historical account will not be given here. Of historical interest are Eistert s book on tautomerism and mesomerism which was published in 1938, a review on — NH-CO— tautomerism by Arndt and Eistert published in 1938, and Heller s account of heterocyclic tautomerism which appeared in 1925. Although more recent works on heterocyclic chemistry (e.g., references 9-11) have dealt incidentally with tautomerism, no unified... 

In the developed countries, stages in the historical development of agricultural production have been characterized by differing combinations of inputs differences in relative proportion ot land, labor and capital, and in the composition of the capital inputs. 

Lindsay, R. B., ed. (1975). Energy Historical Development of the Concept. Stroudsburg, PA Dowden, Hutchinson, Ross. 

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