Special Application

Specialized applications of batteries cover military and space technology and some scientific instruments. Examples of such battery-powered devices are satellites, space probes, rockets, bathyscaphes and other submersible craft, electrically driven torpe-dos, meteorological balloons, and so forth. Specialized batteries may be divided into two subdivisions power sources for short-term loads (typically for a single discharge) and those for long-term low-drain discharge. 

Supported Ionic Liquids Fundamentals and Applications, First Edition-Edited by Rasmus Fehrmann, Anders Riisager, and Marco Haumann. 

Because of the interest in the potential biological applications of complexes containing coordinated dioxygen, and the importance of superoxides as a by-product of aerobic metabolic processes, aqueous stud- 

The reduction of dinuclear complexes of / -peroxo- and /x-superoxo-cobalt(III) species have been investigated using both mononuclear (171) and dinuclear (172) metal-centered reductants for many years. Definitive methods for the preparation of these complexes have been reported (173). 

Somewhat more recently, the reduction of the superoxo-containing species [(eda)2Co(/x-NH2)(/x-02)Co(eda)2]4+ and its peroxo-containing counterpart [(eda)2Co(/x-NH2)(jLt-02)Co(eda)2]3+ with sulfite, nitrite, and arsenite have been reported (174). When sulfite or nitrite are used as the reductants, the ultimate product formed contains bridging sulfate or nitrate, respectively, in place of the /x-02 group. In the case of arsenite, however, the arsenite is oxidized to arsenate (AsO3-), and a complex with a /x-OH group in place of the /t-02 group results. 

The superoxo-containing species [(NC)6Co(/u.-02)Co(CN5]5 can be reduced with thiols such as 2-aminoethanethiol or L-cysteine (175), and the reduction reaction is catalyzed by copper(II) ions in aqueous solution. When copper(II) is present, the role of the thiol is to reduce cop-per(II) to copper(I), which then reacts with the superoxo species through an inner-sphere mechanism. Conversely, when the superoxo complex [(H3N)5Co(/x-02)Co(NH3)5]5+ is reduced with thiol (176), the reaction follows an outer-sphere mechanism, as would be expected. Ascorbic acid also reduces both complexes (177), but only the reduction of the cyano-containing complex exhibits copper(II) catalysis. 

A spectroscopic study of Claus blue, with comparisons to the much better characterized (180) ion [Rh2(0H)2(H20)n(/u,-02)]3+, was thus undertaken (181). By the use of UV-vis, ESR, and IR/Raman spectroscopies, as well as magnetic susceptibility measurements and voltamme-tric studies, it was determined that Claus blue solutions actually contain superoxo-dirhodium complexes, and not RhO2- ions. The su-peroxo bridge does not, however, derive from dioxygen, but from oxidation of coordinated hydroxide. Finally, Claus blue solutions were demonstrated to be good starting materials for the preparation of superoxo-dirhodium carboxylate complexes, which could be isolated and characterized. 

While solution crystallization is the main focus of this book, there are applications which are special cases of the CrystaUization methods described in earher chapters. For example, a process requiring sterile crystallization is a special example of an antisolvent addition and is presented in Example 11-1. In this particular example, it is necessary to produce fine particles in order to meet drug dissolution time specifications in the final single-dose vials. Furthermore, the material is thermally unstable. Therefore, special precautions have to be taken to minimize any degradation during processing. 

Integration of CrystaUization with other process operations, specifically reaction, is another aspect of crystallization that has significant potential to improve overaU process economics. In Examples 11-2 and 11 -3, two cases are presented in which products are selectively crystallized during reaction. As a result, reaction selectivity, yield, and the cost of raw materials are significantly improved. Furthermore, solvent recovery is simplified since the same solvent is used in both reaction and crystallization. This type of operation can provide significant improvement in process economics and should be part of the development of crystallization processes when applicable. 

Other crystallization techniques that are less frequently applied in the pharmaceutical industry, such as melt and freeze crystallization, may be applicable for some processes. In Example 11-4, purification of dimethyl sulfoxide (DMSO) is presented. In this case, low-level impurities, primarily dimethyl sulfide, are removed by controlled fractional crystallization from the melt (DMSO is a liquid above 18.45°C), in combination with adsorption of impurities from the unfrozen liquid. In the feed DMSO prior to the crystallization step, the impurities, while unacceptable, are at too low a level to be removable by adsorption alone. 

In Example 11-5, freeze crystallization of imipenem. which has lower stability in solution at room temperature, is presented. In this process, the product is rapidly frozen to an amorphous solid state to conserve its chemical purity. The temperature is then raised (still below the fieezing temperature at this stage), and the amoiphous solid converts to a crystalline solid over time. After the completion of the solid-state transition phase, the lyophilization drying cycle is initiated. 

Resolution of optical isomers via preferential crystallization is outlined in Chapter 7, Example 7-6, as an example of the use of tightly controlled supersaturation in a cooling crystallization. This process is discussed in greater detail in Example 11 -6. The process for resolution of optical isomers utilizes crystallization kinetics, instead of equilibrium solubility, to accomplish the desired isomer separation. It is a proven technique and has been in long-term 

Various modem accessories (ATR crystals, acoustic detectors, infrared microscopes, polarization modulation technique) as well as hyphenation techniques have substantially expanded the field of application of infrared spectroscopy. Applications of IR spectroscopy to surface investigations (characterization of the surface, physi-sorption and chemisorption studies, catalytic properties) are reviewed in [7-9]. Applications of hyphenated techniques, in particular combinations with chromatography, are given in [8]. 

In the previous chapters, phase equilibria as well as chemical equilibria have been thoroughly discussed. For the development of a process model, it is the usual way to describe the chemical reactions first, and then focus on the phase equilibria for the separation process. However, there are some substances where special models have to be developed, as phase equilibria and chemical reactions have a strong influence on each other. Furthermore, components occur which do not exist in the pure form so that pure component properties cannot be assigned in the usual way. 

The strategy for the development of a process model mentioned above cannot be applied in these cases. In this chapter, two examples for special process models are presented. 

The actinometers described in the section Selected Chemical Actinometers are mostly used to measure the intensity of monochromatic radiation emitted by conventional sources, such as mercury or xenon arc lamps, metal halide lamps, etc. In this section, special applications of chemical actinometer will be reviewed, including the measurement of intensities of lasers and polychromatic light sources. In addition. 

In summary, ferrioxalate can be used for actinometric measurements of high-intensity pulsed or CW sources, in the UV and visible wavelength region. However, reliable results are only obtained for pulse energies of less than 5mJ, 

Laser Intensity Measurements with the Azobenzene Actinometer 

The azobenzene actinometer has been calibrated for intensity measurements with pulsed nitrogen, excimer, and Nd YAG lasers. Comparative actinometric measurements of the radiation intensity of a weak nitrogen laser (337.1 nm, 5 ns, and 5mJ/pulse) utilizing ferrioxalate (vide supra) and a dilute (10 M) azobenzene solution resulted in an isomerization quantum yield identical to that obtained using the 334-nm mercury line (14). Thus, we conclude that a concentrated (6.4x 10 M) azobenzene solution can be used in the same way as described for actinometric measurements of the mercury line at 334 nm (15) with an calibration factor of W=3.6x 10 Einsteincm [see Eq. (14)]. 

Similarly, intensity measurements utilizing a pulsed XeCl excimer laser (308 nm, 15 ns, and 150 mJ/pulse) have been carried out using a dye laser unit as flow-through cell for a lO M azobenzene solution (18). A linear correlation was found between the increase in absorbance at 358nm and the number of laser pulses (Ap), and the energy (E ) per laser pulse can be calculated using Eq. (21), i.e.. 

In the first edition we discussed several examples of employing certain properties of supercritical fluids in ways other than merely extractive in this edition we add several new examples that exploit transport, surface tension, and other properties of supercritical fluids and their solutions. 

This section discusses the selection and applicadon of flame arresters for quenching flames from gases with high fundamental burning velocides and/or the propensity to self-decompose. 

Several types of flame arresters have been tested for hydrogen service and fonnd acceptable for qnenching of hydrogen-air and hydrogen-methane-air mixtnres. 

Some designs of hydraulic (liquid seal) flame arresters have been sric-cesshilly tested for hydrogen service. NAO has designed and snccessfully tested and provided a hydraulic flame arrester for hydrogen-air applications (Straitz 1999). This design is for detonations and has dual liquid seal chambers with shockwave breakers. Rao (1980) also provides information 

Acetylene may propagate decomposition flames in the absence of any oxidant above certain minimum conditions of pressure, temperature, and pipe diameter. Acetylene, unlike most other gases, can decompose in a detonative manner. Among the different types of flame arresters that have proven successful in stopping acetylene decomposition flames are hydraulic (liquid seal) flame arresters, packed beds, sintered metal, and metallic balls (metal shot). 

Sutherland and Wegert (1972) describe the successful use of the Linde hydraulic valve arrester in stopping an acetylene decomposition detonation. As previously noted, these flame arresters are no longer being made by Linde (now Praxair Inc,), but are still available from ESAB Welding Sc Cutting Products of Florence, SC. 

Department of Physiology and Biochemistry, University of Southampton, England 

Hydrogen Movement within the Cell, and Incorporation into 

0 We thank Drs. M. Akhtar and D. C. Wilton for helpful discussions during the 

Tables of Known Sugars Specifically Labeled with Isotopes of Hydrogen.. 181 

This article will be generally confined to a discussion of sugars in which a hydrogen isotope forms a carbon-hydrogen isotope bond. 

most field effect liquid crystalline displays (LCDs) use alignment layers to achieve high contrast ratio and maximum brightness (26). The conventional alignment technique is mechanical rubbing, in which a substrate is coated with a thin polymer film and then buffed with a cloth to control the direction of liquid crystal on the substrate surface. 

The advantage of this method is that it is suitable for mass production. However, the rubbing method has certain drawbacks, including the production of dust and electrostatic charges, which is particularly disadvantageous for manufacturing high-performance LCDs. 

Alternatively, the method for producing uniform liquid crystal alignment in a liquid crystal cell comprises the steps of providing a substrate, and printing at least one layer of a polymer ink solution onto the substrate with a printer to form a printed pol mier ink layer having a predetermined thickness. Air is then blown upon the printed polymer ink layer to produce induced anisotropy on the printed pol mier ink layer. Using the substrate in a liquid crystal cell provides alignment of liquid crystals in the liquid crystal cell (26). 

Metal Heat capacity ) K- kr Component weight g Temperature Increase °C 

In the US space shuttles, some brake components and structural parts use beryllium. Both the low density and the high heat capacity are significant here. 

The nuclei of beryllium atoms are simple 4 protons and 5 neutrons. Because of that their scattering of X-rays is negligible and the radiation is transmitted. Thin foils of the metal are therefore used as window material for X-ray tubes. On the other 

Beryllium oxide, beryllia, is an electrical insulator but a good heat conductor. It is transparent to microwaves and may be used in microwave communication systems. Beryllia serves mainly as a substrate for high-density electronic circuits for highspeed computers, lasers and automotive ignition systems. 

In general, a PVC resin contains aids such as a lubricant and a processing aid, in order to improve its moldability and processability and to enable it to stably pass through various processes. Polymers such as a copolymer mainly composed of methyl methacrylate have been used as such polymer processing aids or lubricants (6,7). 

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The subroutine is well suited to the typical problems of liquid-liquid separation calculations wehre good estimates of equilibrium phase compositions are not available. However, if very good initial estimates of conjugate-phase compositions are available h. priori, more effective procedures, with second-order convergence, can probably be developed for special applications such as tracing the entire boundary of a two-phase region. 

Special products silicones, silicates, polyphenylethers, used rarely and for very specialized applications because they are expensive materials. 

Road paving. This includes bitumen, cutbacks and fluxed bitumen as well as emulsions. Each of these products is subject to very special application techniques. This list is completed by the use of poured asphalt, even though this product is better suited to smaller surfaces sidewalks, courts, etc., than to pavements. Since the middle of the 1980 s, air-blown bitumen is no longer used for road construction. 

Since metal-ceramic technology due to some reasons is the more expensive technology, its use presently is restricted to high-power or special applications. 

Due to the pulsed radiation output of the LINAC the detectors and the detector electronics have to handle very high counting rates in very short periods. Therefore the detectors have to work in a mode, where the detector output is integrated for one or several beam pulses. For that purpose the crystals are coupled to photo- diodes. Their currents are read out and analysed by the electronic board, which has been developed for this special application. 

In order to obtain a high signal-to-noise ratio sufficient acoustical power is necessary. For special applications a programmable pulser (transmitter) is required in order to optimize the frequency spectrum. 

For special applications such as air coupled testing a special programmable transmitter board was developed. This transmitter generates rectangular and burst signals, which increase the acoustical power in an optimized frequency range, and provides a superior signal-to-noise ratio. 

The Evaluation system is a Windows based open system through DLL, Dynamic Link Library, which provides great flexibility in evaluation and presentation of data. It also makes it possible to customise evaluation and images for special applications The time gates can be set after testing and there is a 256 colour range for amplitude. The software include FFT -facilities which enables measurements on used probes for parameters such as center frequenzy and bandwidth. 

Another specialized application of EM image contrast is mass measurement. Using the elastic dark-field image in the STEM or the inelastic image in the EETEM, a direct measurement of the scattering mass can be performed. Eor reviews on this teclmique see [60.61]. 

For bulk structural detemiination (see chapter B 1.9). the main teclmique used has been x-ray diffraction (XRD). Several other teclmiques are also available for more specialized applications, including electron diffraction (ED) for thin film structures and gas-phase molecules neutron diffraction (ND) and nuclear magnetic resonance (NMR) for magnetic studies (see chapter B1.12 and chapter B1.13) x-ray absorption fine structure (XAFS) for local structures in small or unstable samples and other spectroscopies to examine local structures in molecules. Electron microscopy also plays an important role, primarily tlirough unaging (see chapter B1.17). 

Kirkwood J G 1934. Theory of Solutions of Molecules Containing Widely Separated Charges witl Special Application to Zwitterions. Journal of Chemical Physics 2 351-361. 

A special application of the Japp-Klingemann/Eischer sequence is in the preparation of tryptamines from piperidone-3-carboxylate salts, a method which was originally developed by Abramovitch and Shapiro[2]. When the piperidone is subjected to Japp-Klingemann coupling under mildly alkaline conditions decarboxylation occurs and a 3-hydrazonopiperidin-2-one is isolated. Fischer cyclization then gives 1-oxotetrahydro-p-carbolines which can be hydrolysed and decarboxylated to afford the desired tryptamine. 

With the exception of pneumatic controllers for special applications, commercial single-loop controllers are almost entirely microprocessor-based. The most basic products provide only the PID control algo-... 

Special applications, such as in high-magnetic fields, require special thermometers. The carbon-glass and strontium-titinate resistance thermometers have the least magnetoresistance effects. 

Mixed-feed operation is used only for special applications, as when liquor at an intermediate concentration and a certain temperature is desired for additional processing. 

Breakup of a low-velocity liquidjet (Ih/elocity) . This governs in special applications like prilling towers and is often an intermediate step in liquid breakup processes. 

There are, however, certain special applications where the filter medium around the edge of the section may be dehberately blinded by painting in order to improve cake discharge. This technique is most frequently used on disk filters, with the result that the actual area may be only 75 to 85 percent of the nominal area. This is a significant deviation from the nominal area and must be considered separately. 

Alternatively, A- ylium names may be formed by a special application of the A convention, according to which the affected atom is considered to be formally derived from a hypothetical parent that has a hydridic hydrogen attached in lieu of the positive charge. Such an operation... 

Manufacturers, depending upon market needs, may adopt all or a few such designs or even have their own designs, still conforming to such stipulations. Special applications may, however, call for a custom-built motor as noted later. As a standard practice all HT motors are custom-built for each application and no rotor designs are prescribed for these. 

Ghosh, S.N., Electric motors lor special applications . Siemens Circuit, V , No. 4, July (1972). 

For special applications, however, such as for normally humid areas, and contaminated or chemically aggressive locutions, epoxy paints tne con.sidered to be more appropriate. They provide a protective coating which is resistant to chemical fumes, corrosion and temperature. Chlorinated rubber paints, which also fall into the same category of protective paints, may also be used for these areas but, not being temperature resistant, are not preferred to epoxy paints. 

These are protection CTs lor special applications such as biased differential protection, restricted ground fault protection and distance protection schemes, where it is not possible to easily identify the elass of accuracy, the accuracy limit factor and the rated burden of the CTs and where a full primary fault current is required to be transformed to the secondary without saturation, to accurately monitor the level of fault and/or unbalance. The type of application tind the relay being used determine the knee point voltage. The knee point voltage and the excitation current of the CTs now form the basic design parameters for such CTs. They are classified as class PS CTs and can be identified by the following characteristics ... 

With application of solid-state technology, this shortcoming of an electromagnetic relay is automatically overcome. The solid-state relays are available with switching stages as many as from 2 to 16. For special applications, they can be designed for even higher numbers of steps. 

There are less exotic ways of increasing the strength of cement and concrete. One is to impregnate it with a polymer, which fills the pores and increases the fracture toughness a little. Another is by fibre reinforcement (Chapter 25). Steel-reinforced concrete is a sort of fibre-reinforced composite the reinforcement carries tensile loads and, if prestressed, keeps the concrete in compression. Cement can be reinforced with fine steel wire, or with glass fibres. But these refinements, though simple, greatly increase the cost and mean that they are only viable in special applications. Plain Portland cement is probably the world s cheapest and most successful material. 

Straight-lobe compressor casings, also called housings or cylinders by different manufacturers, are furnished in cast iron by all vendors. There is an optional aluminum construction available for special applications. Inlet and outlet are suitable for a 125 pound standard ANSI flanged connection. 

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