High heat capacity

Gaseous helium is commonly used as the working fluid ia closed-cycle cryogenic refrigerators because of chemical iaertness, nearly ideal behavior at all but the lowest temperatures, high heat capacity per unit mass, low viscosity, and high thermal conductivity. 

Specific Heat. In some appHcations refractories are used for heat-exchange purposes on the regenerative principle, for instance, in blast-furnace stoves. High heat capacity is requited in such appHcations (Table 8). 

Using high heat capacity systems, some experimenters tried to stabilize around the (non-existent) unstable middle intersection, and believed that they had accomplished this. In reality they were seeing a jump to a higher... 

Wood has very useful thermal properties. Dry wood has a low thermal conductivity and a high heat capacity, and is resistant to thermal decomposition at temperatures up to 250°C for short periods of time. 

Boilers are heat-transfer devices, wherein water, in the form of either liquid water or gaseous steam, is commonly employed as a medium for the transport of heat to some distant point of use. Although other heat-transfer mediums are sometimes utilized, water is particularly suitable because of its relative abundance, low cost, and high heat capacity. It is generally the medium of choice in most boiler applications, whether for domestic, commercial, institutional, or industrial purposes. 

The temperature of a sample is constant at its melting and boiling points, even though heat is being supplied. The slope of a heating curve is steeper for a phase with a low heat capacity than for one with a high heat capacity. 

Recently, room temperature ionic liquids (RT-ILs) have attracted much attention for their excellent properties, e.g., wide temperature range of liquid phase, ultra-low vapor pressure, chemical stability, potential as green solvents, and high heat capacities [64,65]. These properties make them good candidates for the use in many fields, such as thermal storage [66], electrochemical applications, homogeneous catalysis [67], dye sensitized solar cells [68], and lubricants [69,70]. 

When ATad < 30°C, heat recuperation is important. The outlet switching temperature will be low so the reaction contribution of the inlet and outlet regions is small. In this situation, inert packing with high heat capacity and low porosity can be used in place of catalyst. The variant is shown in Fig. 7. 

The high heat capacity associated with the large mass of liquid facilitates control of the reactor and provides a safety factor for exothermic reactions that might lead to thermal explosions or other runaway events. 

A piston compressor (in case of a Stirling type PTR) or a combination of a compressor and a set of switching valves (GM type PTR) are used to create the pressure oscillations. The regenerator of a PTR stores the heat of the gas during a half-cycle and, therefore, must have a high heat capacity, compared to the heat capacity of the gas. 

Check, if possible (with thermometers), that all parts of the DR below the 4K flange, including the experiment, reach the bath temperature (4.2 K). Parts which remain at temperatures well above 4K (with high heat capacity) may cause mysterious behaviours of the DR, and most times it is necessary to go back to step 4. 

Because of their high heat capacity, only few of the thermometers described in Chapter 9 can be used as sensors for detectors. Resistance (carbon) sensors were used for the first time in a cryogenic detector by Boyle and Rogers [12] in 1959. The carbon bolometer had a lot of advantages over the existing infrared detectors [13]. It was easy to build, inexpensive and of moderate heat capacity due to the low operating temperature. 

This ensures economically reasonable cycle times together with optimal physical properties due to the high heat capacity of PET, although this mould temperature does not meet the maximal rate of crystallization for PET which was determined to be at 170 C. 

For some process application, it is necessary to find mixtures that are not miscible in water, is liquid at the operating condition (around 300 K and 1 atm) and can absorb heat (that is, has a high heat capacity). Find the mixture with the highest heat capacity (in the liquid phase). 

Water offers a number of important properties as a solvent for polymerization reactions. As well as its high polarity, which gives a markedly different miscibility with many monomers and polymers compared to organic solvents, it is nonflammable, nontoxic and cheap. Water also has a very high heat capacity that sustains heat exchanges in a number of very exothermic polymerizations. Largely because of these factors, polymerizations are now widely carried out in aqueous media, and, for example, more than 50% of industrial radical polymerizations are carried out in water [19]. 

Because of its high heat capacity, ammonia is used as the working fluid in Ocean Thermal Energy Conversion (OTEC) units. See http //www.nrel.gov/otec/for more information. 

The relatively high heat capacity of water has important consequences for climate and life on Earth. For example, seasonal changes in atmospheric temperatures are moderated at mid-latitudes via adsorption of heat by the ocean s surfece waters during the summer and release of this heat diudng the winter. Thus, mid-latitude coastal zones experience much smaller seasonal atmospheric temperature fluctuations than occur inland. 

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