Special interest groups

The usual acceptor and donor dopants for Al Ga As compounds are elements from groups II, IV and VI of the periodic table. Group II elements are acceptors and group VI elements are donors. Depending on the growth conditions. Si and Ge can be either donors or acceptor, i.e. amphoteric. This is of special interest in LEDs. 

The basic stmcture of a naphthalocyanine dye can be seen in Figure 6 (12). By varying the central atom Y, the organic (polymeric) group at the central atom, and the substituents and X, an adjustment to the desired property profile, especially improved solubihty, can be achieved. Naphthalocyanines with sihcon as central atom evoke special interest, eg, the biaxiahy substituted silicon—naphthalocyanine (13) wherein the central Si bears... 

Of special interest in scale-control systems is the type in which the motion of the scale beam is sensed by a differential transformer or a group of load cells. The output of such devices is proportional to the displacement of the scale beam, which in turn is proportional to the amount of material in the weigh bucket. Many designs use loadsensing devices such as strain gauges or transducers. These eliminate the need for a scale-beam mechanism. The weigh vessel is mounted directly on the load-sensing devices. This provides many benefits in... 

In contrast to the previous method (equation 70), reaction 72 made possible the preparation of iodonium triflates from functionalized acetylenes bearing an electron-withdrawing group such as tosyl, cyano, or carbonyl [138]. Of special interest is the application of this method to the synthesis of the bisiodonium acetylenic salt [139, 140] (equation 73). 

Pure piperitone was subjected to the action of purified hydrogen, in the presence of a nickel catalyst, for six hours, the temperature ranging between 175° to 180° C. The double bond in piperitone was readily opened out with the formation of menthone, but further action of the hydrogen under these conditions did not reduce the carbonyl group, even after continued treatment for two days. Under correct conditions, however, the reduction to menthol should take place. The ease with which menthone is formed in this way is of special interest, not only in connection with the production of this ketone, but also as a stage in the manufacture of menthol. 

With strong incentives for businesses and other special interest groups, and weak incentives for individual voters, it is not surprising that many environmental regulations have often been less successful at preventing harm than the more traditional property rights-based approaches. Thus, while privately owned lands and resources are generally healthy and well preserved, many resources that are not owned, such as air or many waterways, are polluted. 

This indirect method of selective benzoylation at C-4 is of special interest in the galacto series (47). Reaction of methyl 4,6-O-benzylidene-a-D-galactopyranoside 97 with NBS afforded the corresponding 6-bromo-4-benzoate (98) in over 90% yield. The axial hydroxyl group at C-4... 

The ABC-transporter superfamily represents a large group of transmembrane proteins. Members of this family are mainly involved in ATP-dependent transport processes across cellular membranes. These proteins are of special interest from a pharmacological point of... 

There is a special interest in the role of neighboring group participation by sulfinyl groups in nucleophilic aliphatic substitution. Thus Martin and Uebel218 found that trans-4-chlorothiane-S-oxide 36 is solvolyzed (50% v/v aqueous ethanol, 140 °C) 630 times faster than the cis isomer 37. This was attributed to the intervention of 38 for the former. 

Fluorinated poly(arylene edier)s are of special interest because of their low surface energy, remarkably low water absorption, and low dielectric constants. The bulk—CF3 group also serves to increase the free volume of the polymer, thereby improving various properties of polymers, including gas permeabilities and electrical insulating properties. The 6F group in the polymer backbone enhances polymer solubility (commonly referred to as the fluorine effect ) without forfeiture of die thermal stability. It also increases die glass transition temperature with concomitant decrease of crystallinity. 

Casey, M., Winteegeeste, T., Special Interest Group on Quality and Trust in Industrial CFD Best Practice Guidelines, European Research Community on Flow, Turbulence and Combustion (2000). 

With the recent Increase In activity at hazardous waste sites where cleanup and remedial action are underway, there has emerged a need for rapid analytical methods for assessing contamination in water, sediment, and soil. Of special Interest, because of widespread use and disposal. Is the group of materials known as PCB s (polychlorinated biphenyls). 

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