One of the principal differences between the use of agar duplicating compounds compared with agar impression materials is that the duplicating compounds are subjected to repeated heating and gelation cycles and also to extended storage at temperatures from 1250 to 1500 F. The change in physical properties of duplicating compounds with use or aging is, therefore, of particular interest in an eva...

Changes of dynamic and structural parameters of egg yolk lecithin (EYL) liposome membranes in the heating-cooling cycles have been studied using the ESR spin probe method. The investigations were conducted in the range of temperatures from -18 degrees C to +60 degrees C. It has been found that in the range of temperatures -15 degrees C to +45 degrees C in both the heating and the cooling run th...

Changes of the electron concentration and mobility in CdTeHg semiconductor alloys subjected to repeated heating–cooling cycles were studied. The role of the initial crystal properties as well as of the glue material keeping the sample on the substrate in the observed changes was examined. PACS numbers: 81.40.Rs, 72.20.Fr

in this paper the changes in the heat capacity of cooling towers has been investigated as a result of injecting combustion products of boilers. in the tower, the air is re-heated through mixing with hot flue gas after passing through the heat exchangers. as a result of this process, the draft of the cooling tower is increased. the additional produced draft depends on the ambient temperature and...

Relaxation and temperature cycles of thermoremanent magnetization, MTRM, in the superspin-glass phase of [Co80Fe20(0.9 nm)/Al2O3(3 nm)]10 have been investigated. The relaxation of MTRM exhibits ageing phenomena. In negative temperature cycles for temperature steps larger than 1 K the magnetic state is retrieved (memory effect) on returning to the measurement temperature. This property is indepe...

This paper examines the effects of monotonic and cyclic temperature changes a model energy pile (diameter=25 mm, length=264 mm) on variations in volumetric water content surrounding unsaturated sand. Water flowed away from during heating to 36°C toward cooling 5°C, causing soil drying wetting near pile, respectively. The change was time-dependent, nonlinear, slower than continued evolve after s...

Exergy is precious energy. On the basis of thermodynamic analysis of thermal processes, one can choose more exergy-saving devices. This is especially important in refrigeration processes, in which the consumption of energy and exergy increases considerably with the falling cooling temperature. The exergy efficiency in terms of exergy losses of vapour compression and sorption cooling processes i...

Combined cooling, heating, and power (CCHP) systems produce electricity, cooling, and heat due to their high efficiency and low emission. These systems have been widely applied in various building types, such as offices, hotels, hospitals and malls. In this paper, an economic and technical analysis to determine the size and operation of the required gas engine for specific electricity, cooling, ...

In this study, thermal behavior of aqueous solutions of methyl cellulose (MC) at a constant temperature of 50 degrees C was analyzed. Various samples were studied for two consecutive heating-cooling cycles. The experiments with the solutions prepared using cold de-ionized (DI) water showed that the rate of gelation was higher for higher MC concentrations. However, the rate was slower during the...