The first attempts

Such an ideal system is almost obtained for the positive electrode and the electrolyte in some complete protonic batteries whose characteristics have been published .  

However, a problem remains at the level of negative electrodes. Their characteristics presented in the early studies were not as good as those of the positive electrodes. Except for gaseous electrodes (hydrogen), the only negative materials used were hydrides such as PtH, PdH, NiH or TiNiH,j, associated with HUP as electrolyte.  

The proton conduction paths are obviously different in the hydride and in HUP the couple HUP/hydride leads to higher overpotentials than with HUP-metallic oxide interface. For that reason, current densities are smaller. 

The major inconvenience of using hydrides as negative electrodes comes from the insufficiently negative value of their potential (about — O.IV versus SHE), and, consequently, the e.m.f of the battery is not very high. 

In order to increase the value of the e.m.f, some authors have described all solid systems using a metal layer (Zn, Pb. ..) pressed on the solid electrolyte (Fig. 37.2) as negative electrode. 

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The first attempt to come up with a standard multitechnique NDE format model fulfilling these requirements was one of the main achievements of the TRAPPIST project, led between 1992 and 1994 in the frame of the European RACE Program [1],... 

Two approaches to quantify/fQ, i.e., to establish a quantitative relationship between the structural features of a compoimd and its properties, are described in this section quantitative structure-property relationships (QSPR) and linear free energy relationships (LFER) cf. Section 3.4.2.2). The LFER approach is important for historical reasons because it contributed the first attempt to predict the property of a compound from an analysis of its structure. LFERs can be established only for congeneric series of compounds, i.e., sets of compounds that share the same skeleton and only have variations in the substituents attached to this skeleton. As examples of a QSPR approach, currently available methods for the prediction of the octanol/water partition coefficient, log P, and of aqueous solubility, log S, of organic compoimds are described in Section 10.1.4 and Section 10.15, respectively. 

One of the first attempts to build a knowledge base for synthetic organic reactions was made by Gelernter s group, through inductive and deductive machine learning [1]. Important work on this topic was also performed by Funatsu and his group [2]. 

Early in the twentieth century, the first attempts to manufacture formamide directiy from ammonia and carbon monoxide under high temperature and pressure encountered difficult technical problems and low yields (23). Only the introduction of alkaU alkoxides in alcohoHc solution, ie, the presence of alcoholate as a catalyst, led to the development of satisfactory large-scale formamide processes (24). 

One of the first attempts to produce polyurethane was from the reaction of an intermediate polyol of 1,3- and l,4-bis(hydroxyhexa uoroisopropyl)benzene m- and -12F-diols) by reaction with epichlorohydrin. This polyol was subsequentiy allowed to react with a commercial triisocyanate, resulting in a tough, cross-linked polyurethane (129,135,139). ASTM and military specification tests on these polyurethanes for weather resistance, corrosion prevention, bUster resistance, and ease of cleaning showed them to compare quite favorably with standard resin formulations. 

Early efforts to produce synthetic mbber coupled bulk polymerization with subsequent emulsification (9). Problems controlling the heat generated during bulk polymerization led to the first attempts at emulsion polymerization. In emulsion polymerization hydrophobic monomers are added to water, emulsified by a surfactant into small particles, and polymerized using a water-soluble initiator. The result is a coUoidal suspension of fine particles,... 

The first attempt to formulate a systematic nomenclature for polymers was based on the smallest repeating stmctural unit it was pubHshed in 1952 by a Subcommission on Nomenclature of the lUPAC Commission on Macromolecules (95). The report covered not only the naming of polymers, but also symbology and definitions of terms. However, these nomenclature recommendations did not receive widespread acceptance. Further progress was slow, with a report on steric regularity in high polymers pubHshed in 1962 and updated in 1966 (96). 

In contrast, various sensors are expected to respond in a predictable and controlled manner to such diverse parameters as temperature, pressure, velocity or acceleration of an object, intensity or wavelength of light or sound, rate of flow, density, viscosity, elasticity, and, perhaps most problematic, the concentration of any of millions of different chemical species. Furthermore, a sensor that responds selectively to only a single one of these parameters is often the goal, but the first attempt typically produces a device that responds to several of the other parameters as well. Interferences are the bane of sensors, which are often expected to function under, and be immune to, extremely difficult environmental conditions. 

Original Synthesis. The first attempted synthesis of i7-biotin in 1945 afforded racemic biotin (Fig. I). In this synthetic pathway, L-cysteine [52-90-4] (2) was converted to the methyl ester [5472-74-2] (3). An intramolecular Dieckmaim condensation, during which stereochemical integrity was lost, was followed by decarboxylation to afford the thiophanone [57752-72-4] (4). Aldol condensation of the thiophanone with the aldehyde ester [6026-86-4]... 

Reduced Properties. One of the first attempts at achieving an accurate analytical model to describe fluid behavior was the van der Waals equation, in which corrections to the ideal gas law take the form of constants a and b to account for molecular interactions and the finite volume of gas molecules, respectively. 

Sucb a construction is cumbersome and requires utmost caution to ensure that the terminals are properly disengaged before the trolley is racked-out. Otherwise it may pull the wires and snap the connections and result in a major repair. It is also possible that, due to human error, the operator may slip to engage the terminals at the first attempt and may have to do it at a second attempt, adding to the downtime, while energizing or replacing a faulty trolley, eventually defeating the purpose of a draw-out system. 

The application of lignin as an adhesive is possible in principle. The first attempt needed very long press times due to the low reactivity (Pedersen process) [161]. This process was based on lignin polycondensation under strong acidic conditions, which led to considerable corrosion problems in the plant [161]. The particles had been sprayed with spent sulfite liquor (pH = 3-4) and pressed at 180°C. After this step, the boards were tempered in an autoclave under pressure at 170-200°C, whereby the sulfite liquor became insoluble after splitting off water and SO2. 

Analytical Work. Analytical work performed on pressure vessel explosions can be divided into two main categories. The first attempts to describe shock, and the second is concerned with the thermodynamic process. 

The first attempts employing two Cjg columns showed that the selectivity was not high enough, although this improved when the first column was substituted by a 5 p.m GFF n internal surface rcversed-phase material. This is known as a restricted-access-material (RAM) column which, since it restricts some compounds because of their size and includes rcversed-phase interaction and ionic exchange, is very useful for analysing herbicides in samples with high contents of humic and fulvic acids (54). 

Nucleophilic displacement reactions One of the most common reactions in organic synthesis is the nucleophilic displacement reaction. The first attempt at a nucleophilic substitution reaction in a molten salt was carried out by Ford and co-workers [47, 48, 49]. FFere, the rates of reaction between halide ion (in the form of its tri-ethylammonium salt) and methyl tosylate in the molten salt triethylhexylammoni-um triethylhexylborate were studied (Scheme 5.1-20) and compared with similar reactions in dimethylformamide (DMF) and methanol. The reaction rates in the molten salt appeared to be intermediate in rate between methanol and DMF (a dipolar aprotic solvent loiown to accelerate Sn2 substitution reactions). 

Unfortunately for the RDF industry, the first attempts at implementing an RDF processing system met with disappointment and failure. With no European technology to draw from, RDF processing evolved from experience and inspiration gained from the U.S. applications. In the earliest processes, the design called for all of the incoming waste to be shred-... 

Zinc should give a potential of -1 - 05 V vs. CU/CUSO4 and should have a driving potential of about -0-25 V with respect to cathodically protected steel. Zinc is therefore sufficiently negative to act as a sacrificial anode, and its first use for such purposes was on the copper-sheathed hulls of warships more than a century ago. The first attempts to fit zinc anodes to steel hulls, however, were a complete failure, for the sole reason that it had not been realised that the purity of the zinc was of paramount importance. The presence of even small amounts of certain impurities leads to the formation of dense adherent films, which cause the anodes to become inactive. 

The interest in asymmetric synthesis that began at the end of the 1970s did not ignore the dihydroxylation reaction. The stoichiometric osmylation had always been more reliable than the catalytic version, and it was clear that this should be the appropriate starting point. Criegee had shown that amines, pyridine in particular, accelerated the rate of the stoichiometric dihydroxylation, so it was understandable that the first attempt at nonenzymatic asymmetric dihydroxylation was to utilize a chiral, enantiomerically pure pyridine and determine if this induced asymmetry in the diol. This principle was verified by Sharpless (Scheme 7).20 The pyridine 25, derived from menthol, induced ee s of 3-18% in the dihydroxylation of /rcms-stilbene (23). Nonetheless, the ee s were too low and clearly had to be improved. 

The first attempt at a catalytic asymmetric sulfur ylide epoxidation was by Fur-ukawa s group [5]. The catalytic cycle was formed by initial alkylation of a sulfide (14), followed by deprotonation of the sulfonium salt 15 to form an ylide 16 and... 

Isolation of F and P. The first attempt to isolate and purify the substances responsible for the light emission of M. norvegica was made by Shimomura and Johnson (1967). They isolated two substances, a protein (P) and a fluorescent compound (F), which produce a blue light... 

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