Air, thermodynamic properties

Extensive tables of the viscosity and thermal conductivity of air and of water or steam for various pressures and temperatures are given with the thermodynamic-property tables. The thermal conductivity and the viscosity for the saturated-liquid state are also tabulated for many fluids along with the thermodynamic-property tables earlier in this section. 

Since air is a mixture of predominantly nitrogen, oxygen, and a host of lesser impurities, there has been less interest in developing precise thermodynamic properties. The only recent correlation of thermodynamic properties is that published by Vasserman, et al. (Barouch, Israel Program for Scientific Translations, Jerusalem, 1970), and is based on the principle of corresponding states because of the scarcity of experimental data. 

TABLE 12-1 Thermodynamic Properties of Moist Air (Standard Atmospheric Pressure, 29 921 inHg)... 

Computes thermodynamic properties of air, argon, carbon monoxide, carbon dioxide, hydrogen, nitrogen, oxygen, water vapor, and products of combustion for hydrocarbons. Computes all properties from any two independent properties. 

Comparing Examples 2a and 2b we notice that the total air pressure has effects on the humidity x, partial density of dry air p total pressure or pressure of humid air, and enthalpy h. Knowing the total pressure is therefore essential in calculations of the thermodynamic properties of humid air. 

Consider the pressure loss in a duct with straight, uniform cross-sectional area. The pressure loss is caused by friction. When different air sheets move against each other, friction is generated. The velocity and thermodynamic properties of air influence the friction. The duct wall has an overall roughness, which causes vortices to be formed with resulting friction in gas. The velocity has a pronounced effect in flow with low velocity, the vortices are small. Eor a straight duct the pressure loss Ap can be determined from... 

There are numerous possible applications for air curtains. For example, air curtains may be used to heat a body of linear dimensions (as used to move the fresh snow from the railway exchanges in Canada) to function as a partition between two parts of one volume to function as a partition between an internal room and an external environment, that have different thermodynamic properties and to shield an opening in a small working volume (see Section 10.4.6). 

Psychrometric chart A chart constructed so that knowing any two air properties the remaining thermodynamic properties of air at that condition can be determined. 

Chlorobenzene(s), 3 602 6 211-225 24 275 Antoine constants, 6 215t from benzene, 3 619t, 620 chlorocarbon/chlorohydrocarbon of industrial importance, 6 227t diffusion coefficient in air at 0° C, l 70t economic aspects, 6 219-222 health and safety factors, 6 218-219 manufacture, 6 213-217 physical and thermodynamic properties, 6 214t... 

F.R. Gilmore, "Equilibrium Composition and Thermodynamic Properties of Air at 24000°K , The Rand Corporation, Research Memorandum RM 1543(1955)... 

Antipova, A.S., Semenova, M.G., Belyakova, L.E. (1999). Effect of sucrose on the thermodynamic properties of ovalbumin and sodium caseinate in bulk solution and at air-water interface. Colloids and Surfaces B Biointerfaces, 12, 261-270. 

The pentahalides of niobium and tantalum are predominantly covalent. Their volatility decreases from the fluorides to the iodides. Nb and Ta belong to the few elements which form stable pentaiodides. Selected physical and thermodynamic properties for the halides are listed in Table 2. All are sensitive to moist air, water or hydroxylic solvents. 

Water activity, a thermodynamic property, is defined as the ratio of the vapor pressure of water in a system to the vapor pressure of pure water at equal temperature, or the equilibrium relative humidity of the air surrounding the system at equal temperature. 

These systems convert LNG to CNG by exploiting the inherent thermodynamic properties of a phase change from liquid to gas of natural gas. By relying on heat transfer from the ambient air to produce CNG, operating costs to produce CNG are reduced significantly from the costs of operating a compressor.4 The quality... 

Frey, W.,Ringsdorf, H., Sackmann, E., Schneider, J. 1987. Preparation, Microstructure and thermodynamic Properties of Homogeneous and Heterogeneous Compound Monolayers of Polymerized and Monomeric Surfactants on the Air/Water Interlace and on Solid Substrates. Macromolecules 20,1312... 

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