Technology, problems

P. E. Gray, J. W. Tester, and D. O. Wood, Energy Technology Problems and Solutions, Energy and the Environment in the 21st Century, MIT Press, Cambridge, Mass., 1991, p. 120. 

Since one of the main chemical and technological problems of conducting polymers is their low stability for long-term applications, and since storage capacity is a quantification of the basic property of these... 

The final chapter, by Clarke, Edye, and Eggleston (New Orleans, Louisiana), deals with the centuries-old technological problem of maximizing yield in the extraction of sucrose from cane or beet juice. Somewhat remarkably, important misconceptions about the fundamental aspects of alkaline degradation of sucrose still persist. The authors of this chapter effectively interpret traditional sugar technology, based largely on empirical art, in clear terms of accepted fundamental principles of chemistry. 

Space resolution of the transducer, in principle, is extremely high. Becanse each BR molecule performs proton pumping, it will be comparable with the protein size (abont 2 mn). In practice, however, it will be limited by the possibility of focusing the light beam. Bnt, in any case, it will be more than in existing transducers, subject to technological problems. 

The first—and central— point in this discussion concerns the pulsed X-ray source. The shortest time scales involved when chemical bonds are formed or broken are of the order of a few femtoseconds. An ideal X-ray source should thus be capable of providing pulses of this duration. Unfortunately, generating them represents a heavy technological problem. The best one can do at present is to use a pulsed synchrotron X-ray source (Fig. 2). Electrons are rapidly circulating in its storage ring at speeds close to the speed of light. X-rays are spontaneously... 

At some point along the way, Leblanc fell in love with chemistry, which was an intrinsic part of upper-class culture in eighteenth-century France. Rich aristocrats studied chemistry and installed laboratories in their chateaus even the king, Louis XVI, believed that the science could help solve a host of society s medical and technological problems. 

Sometimes technological problems forbid the size of an operation to exceed a certain value. For instance, in the batch polymerization of polyethylene and polystyrene, it is important to maintain the temperature below a critical value, because otherwise the material will be damaged. Since this is an exothermic reaction, it means the energy must be removed as fast as it is formed. If it is not, the temperature will begin to rise, which will increase the rate of polymerization. This will result in an acceleration of the temperature rise and the result will be a discolored batch. This requirement establishes a limit on the size of the reactor. The practical significance is demonstrated in the polystyrene case-study example following Chapter 5. 

The immediate application of phototrophic bacteria in biotechnological systems of H2 generation is not possible due to many scientific and technological problems. Some of them... 

As expected, the destruction is proceeding asymmetrically, meeting domestic financial and technological problems with construction of destruction facilities including problems of acceptance by population in the respective regions. It is therefore expected, that the scheduled 10 years term for total CW destruction according to the CWC will not be managed and the allowed exception to extend the destruction period for another 5 years has been already asked for, by the Russian Federation and also by the US. 

Markov theory can be applied advantageously to a variety of technological problems of day-to-day operation in an industrial environment. Such problems transcend the realm of purely physico-chemical and fundamental electrochemical considerations, and are closely linked to (large-scale) technological aspects. This Section demonstrates the utility of the Markovian approach to selected examples. 

The early years in the development of automated analytical techniques were largely devoted to solving the scientific and technological problems of designing and constructing equipment capable of performing analytical procedures in a precise and repeatable manner, with sufficient reliability to allow it to fulfil its task with minimal supervision. 

During the last decade, research efforts in the field of LC-MS have changed considerably. Technological problems in interfacing appear to be solved, and a number of interfaces have been found suitable for the analysis of flavonoids. These include TSP, continuous-flow fast-atom bombardment (CF-FAB), ESI, and APCI. LC-MS is frequently used to determine the occurrence of previously identified compounds or to target the isolation of new compounds (Table 2.11). LC MS is rarely used for complete structural characterization, but it provides the molecular mass of the different constituents in a sample. Then, further structural characterization can be performed by LC-MS-MS and MS-MS analysis. In recent years, the combination of HPLC coupled simultaneously to a diode-array (UV-Vis) detector and to a mass spectrometer equipped with an ESI or APCI source has been the method of choice for the determination of flavonoid masses. Applications of LC-MS (and LC-MS-MS) in flavonoid... 

The effect of using mixtures of surfactants on micelle formation, monolayer formation, solubilization, adsorption, precipitation, and cloud point phenomena is discussed. Mechanisms of surfactant interaction and some models useful in describing these phenomena are outlined. The use of surfactant mixtures to solve technological problems is also considered. 

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