Mass properties

Psychrometrics. Psychrometrics is the branch of thermodynamics that deals specifically with moist air, a biaary mixture of dry air and water vapor. The properties of moist air are frequentiy presented on psychrometric charts such as that shown ia Figure 2 for the normal air conditioning range at atmospheric pressure. Similar charts exist for temperatures below 0°C and above 50°C as well as for other barometric pressures. AH mass properties ate related to the mass of the dry air. 

The systems of interest in chemical technology are usually comprised of fluids not appreciably influenced by surface, gravitational, electrical, or magnetic effects. For such homogeneous fluids, molar or specific volume, V, is observed to be a function of temperature, T, pressure, P, and composition. This observation leads to the basic postulate that macroscopic properties of homogeneous PPIT systems at internal equiUbrium can be expressed as functions of temperature, pressure, and composition only. Thus the internal energy and the entropy are functions of temperature, pressure, and composition. These molar or unit mass properties, represented by the symbols U, and S, are independent of system size and are intensive. Total system properties, J and S do depend on system size and are extensive. Thus, if the system contains n moles of fluid, = nAf, where Af is a molar property. Temperature... 

WA Hunke, LE Matheson. Mass properties of Co(polycthcr) polyurethane membranes. Part 2. Permeability and sorption characteristics. Int J Pharm 1313-1318, 1981. 

A study of the polymerization kinetics of methyl methacrylate, in the presence of PBN, and of molecular-mass properties of the obtained polymers shows that the systems react by the pseudoliving mechanism (699). In the first stages of the polymerization process, PBN reacts with oligomeric radicals, forming stable nitroxyl radical-spin adducts A-, see Scheme 2.207. 

EngrgDesHndbk, Recoilless Rifle Weapon Systems , AMCP 706-238 (1976), 8-24 to 8-25 9) L.R. Rollstin, Experimental Determination of the Artillery Shell Mass-Property/Trajectory-Drift Relationship , JSpacecraft Rockets 16 (2) (1979), 108-14... 

We now see that the model inertial universe, with (23) as a global relationship, bears a close formal resemblance to a universe filled purely with Einsteinien photons—the difference is, of course, that the particles in the model inertial universe are assumed to be countable and to have mass properties. This formal resemblance means that the model inertial universe can be likened to a quasiphoton fractal gas universe. 

Since we are concerned here primarily with the properties of solutions, represent molar (or unit-mass) properties of the solution by the plain symbol Partial properties are denoted by an overbar, and a subscript identifies the specie giving the symbol Mf. In addition, we need a symbol for the properties of th individual species as they exist in the pure state at the T and P of the solution. These molar (or unit-mass) properties are identified by only a subscript, and the symbol is Mj. In summary, three kinds of properties used in solution thermody namics are distinguished by the following symbolism ... 

Consider a physical property (such as the total Gibbs free energy G) of a continuous mixture, the value of which depends on the composition of the mixture. Because the latter is a function of, say, the mole distribution n(x), one has a mapping from a function to (in this case) a scalar quantity G, which is expressed by saying that G is given by afunctional of n(x). [One could equally well consider the mass distribution function m(x), and consequently one would have partial mass properties rather than partial molar ones.] We use z for the label x when in-... 

The effect of synthesized modifiers on fluorosiloxane rubbers is determined on the basis of fluorosiloxane rubber CKTFT-100 As seen fix)m data presented in Table 3, characteristics of fluorosiloxane rubber depend on quantity of introduced modifier and its molecular mass Properties of rubber compounds are highly dependent on modifier concentrations. Optimal modifier content amounts to 6 - 7%. Increase in molecular mass of modifier on transition from modifier II to modifier VI leads to increase in tear strength and relative elongation in comparison to the control specimen (modifier concentration = 0). Also, after thermal treatment at 250 °C for 24 h in the presence of modifier VI, improvement of all fluorosiloxane rubber compound properties is observed. 

Fig. 10.3. Predictions about the size of the ore deposits hump in Fig. 10.2 are based on certain mass properties of known ore deposits. For example, the graph shows that the largest known deposit of each scarce metal is approximately proportional to crustal abundance.

These statistics underscore the importance of the continental shelf areas to the structure and function of the Arctic Ocean system. Arctic shelf seas are the primary sites for processing and modifying the characteristics of waters received from the Pacific and Atlantic Oceans and the numerous large rivers that drain the circumpolar continents. All of these inflows are substantially altered on the shelves by mixing and by interactions with the ice cover, atmosphere, seabed and biota. The water mass properties that generate and maintain the halocline in the Arctic Ocean (see Section 5.2.1) are derived from the modification of inflowing Atlantic and Pacific waters while transiting continental shelves. 

One of the major attributes of ceramics is that as a class of materials, they are less dense than metals and hence are attractive when specific (i.e., per unit mass) properties are important. The main factors that determine density are, first, the masses of the atoms that make up the solid. Clearly, the heavier the atomic mass, the denser the solid, which is why NiO, for example, is denser than NaCl. The second factor relates to the nature of the bonding and its directionality. Covalently bonded ceramics are more open" structures and tend to be less dense, whereas the near-close-packed ionic structures, such as NaCl, tend to be denser. For example, MgO and SiC have very similar molecular weights ( 40 g) but the density of SiC is less than that of MgO (see Worked Example 3.4, and Table 4.3). 

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