Indirect conversion process

Native enzymes, 32 419-420 Natrolite. 33 215, 224, 255 Natural gas, indirect conversion processes, 39 222... 

The most widely used fiat detector (FD) design is based on a two-level, indirect conversion process of X-rays to light (Granfors et al. 2001 Antonuk et al. 1997 Spahn et al. 2000 Yamazaki et al. 2004 Ducourant et al. 2003). In the first step, the X-ray quantum is absorbed by a fluorescence scintillator screen, e.g., a cesium iodide (Csl) substrate, converting it into visible light. In the second step, this light is received by a photodiode array, e.g., based on amorphous silicon (a-Si), and converted into electrical charge. 

The two direct conversion processes were compared against a conventional indirect conversion process. In performing process comparisons, emphases were ... 

Comparison of Direct and Indirect Conversion Processes. To make direct comparison between the OCE cases and the SRM/DPOM cases, a fluid-bed MTG process must be attached to the end of the latter cases to convert CH3OH into CJ hydrocarbons. Following approximate rules of this process, derived based on commercial plant design data (Avidan et al. (1986)), were used ... 

Gasification. Gasification of coal is used to provide gaseous fuels by surface and underground appHcations, Hquid fuels by indirect Hquefaction, ie, catalytic conversion of synthesis gas, and chemicals from conversion of synthesis gas. There are also appHcations in steelmaking (see Coal conversion PROCESSES, gasification). 

The conversion of aromatic compounds comprises coupling, nuclear and ben-zylic substitution, and in some cases, addition. Homo- and in a more limited scope, heterocoupling is achieved for unsubstituted and substituted aromatic compounds in direct or indirect anodic processes. Chemically, there is a limited variety of expensive oxidation reagents available, but a large scope of transition... 

The direct conversion deals with the straight hydrogenation of carbon monoxide to paraffins, olefins and heteroatom (oxygen, nitrogen) containing products. The indirect conversion invokes intermediates such as methanol, methyl formate and formaldehyde. The latter ones in a consecutive reaction can yield a variety of desired chemicals. For instance, acetic acid can be synthesized directly from CO/H2, but for reasons of selectivity the carbonylation of methanol is by far the best commercial process. 

The aforementioned E — D nonadiabatic interactions also lead to efficient, i.e., femtosecond internal conversion processes which we now briefly address. The presence of such processes is indicated indirectly by experimental studies, where Bz+ has been prepared initially in the E state, but fragmentation been found to occur via lower (even the X) electronic states [45,46]. To describe this non-radiative decay... 

The present analysis relies on - and extends - the comprehensive theoretical study of Refs. [23,24] on the multi-state interactions in the manifold of the X — E states of Bz+. Like this recent work, it utilizes an ab initio quantum-dynamical approach. In Refs. [23,24] we have, in addition, identified strong coupling effects between the B — C and B — D electronic states, caused by additional conical intersections between their potential energy surfaces. A whole sequence of stepwise femtosecond internal conversion processes results [24]. Such sequential internal conversion processes are of general importance as is evidenced indirectly by the fluorescence and fragmentation dynamics of organic closed-shell molecules and radical cations [49,50]. It is therefore to be expected that the present approach and results may be of relevance for many other medium-sized molecular systems. 

Oil shale represents an enormous reserve of fossil fuel for domestic and foreign needs (1,2). Shale oil production can be divided into direct and indirect heating processes (2). In direct heating, some of the products or some other fuel is combusted to raise the oil shale to the necessary temperature for conversion to gas and oil while an indirect process transfers heat from an outside source. Although high yields have been demonstrated in some indirect procedures (3), the application to in situ retorting has been limited. Direct processes developed for in situ recovery of shale oil have not demonstrated sufficient control of the underground combustion for reliable operation. 

FIGURE 9.1 I Schematic diagram of the converter section of a contact sulfuric acid plant employing an interpass absorption system for both better sulfur conversion and emission abatement. Product acid (or oleum) is cooled indirectly with process water prior to storage for sale. 

To overcome the drawbacks of the direct conversion of n-butenes. Bayer has developed an indirect oxidation process that helps to improve the overall selectivity of the operation, and whichconsists in passing through theantermediate formation of secondary butyl acetate. Acetic arid is manufactured in two steps according to the following reaction mechanism ... 

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