Heating, dielectric, applications

Of great importance to dielectric heating applications Is the runaway effect or the uncontrolled rise In temperature In a material brought about ts a result of a positive slope, de dT, of the e vs T response. A typical excmple Is the case of hot pressed boron nitride Its dielectric properties... 

Abstract Current microwave-assisted protocols for reaction on solid-phase and soluble supports are critically reviewed. The compatibility of commercially available polymer supports with the relatively harsh conditions of microwave heating and the possibilities for reaction monitoring are discussed. Instrmnentation available for microwave-assisted solid-phase chemistry is presented. This review also summarizes the recent applications of controlled microwave heating to sohd-phase and SPOT-chemistry, as well as to synthesis on soluble polymers, fluorous phases and functional ionic liquid supports. The presented examples indicate that the combination of microwave dielectric heating with solid- or soluble-polymer supported chemistry techniques provides significant enhancements both at the level of reaction rate and ease of purification compared to conventional procedures. 

Equally high terminal selectivity was achieved by application of low-power micro-wave dielectric heating in Eq. (11.3) 87 % of the /1-product was isolated. This high re-... 

Zhang X, Hayward DO (2006) Applications of microwave dielectric heating in environment-related heterogeneous gas-phase catalytic systems. Inorg Chim Acta 359 3421... 

Mingos, D.M.P. and Baghurst, D.R. (1991) Applications of microwave dielectric heating eflFects to synthetic problems in chemistry. Chem. Soc. Rev., 20, 1-47. 

Dielectric Properties of Explosives. In many experiments with expls it is necessary to rapidly heat the expl. The common technique is to introduce heat by conduction. Experiments of rapidly heating expls are difficult to treat theoretically because the temp is not known at a small fraction of a second after the start of heat conduction. As a result, interest is found in the rapid body heating of expls where large thermal gradients can be avoided. The most obvious applicable technique is"dielectric heating fRef 1)... 

In summary, it is apparent that the application of dielectric heating to chemical reactions may result in different reaction rates and product distributions, and chemists... 

The combination of microwave-assisted chemistry and solid-phase synthesis applications is a logical consequence of the increased speed and effectiveness offered by microwave dielectric heating. While this technology is heavily used in the pharmaceutical and agrochemical research laboratories already, a further increase in the use of microwave-assisted solid-phase synthesis both in industry and in academic laboratories can be expected. This will depend also on the availability of modern microwave instrumentation specifically designed for solid-phase chemistry, involving for example dedicated vessels for bottom filtration techniques. 

In hardwood plywood, cold presses without heat application are occasionally used where curved plywood in particular is desired. Dielectric heat curing of the plywood glue lines as a means to increase productivity is sometimes used in conjunction with this process. The acid salt becomes critically important in these cases. 

There are two electromagnetic processes in use today induction and dielectric. Induction is more widely used, and there are several equipment manufacturers that will provide individual heaters or complete bonding systems. Dielectric heating, primarily microwave heating, is less utilized but is finding application in certain niche markets. 

Use of specific forms of radiant energy, infrared, ultraviolet, dielectric heating, etc., can allow specific separations to be made. The separation of clear and colored grains of glass and the separation of different metals are possible applications of the thermoadhesive method being considered in the field of solid-waste processing. 

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