Specific gravity, definition

Physical Properties. Physical properties of waste as fuels are defined in accordance with the specific materials under consideration. The greatest degree of definition exists for wood and related biofuels. The least degree of definition exists for MSW, related RDF products, and the broad array of ha2ardous wastes. Table 3 compares the physical property data of some representative combustible wastes with the traditional fossil fuel bituminous coal. The soHd organic wastes typically have specific gravities or bulk densities much lower than those associated with coal and lignite. 

When simple Hquids like naphtha are cracked, it may be possible to determine the feed components by gas chromatography combined with mass spectrometry (gc/ms) (30). However, when gas oil is cracked, complete analysis of the feed may not be possible. Therefore, some simple definitions are used to characterize the feed. When available, paraffins, olefins, naphthenes, and aromatics (PONA) content serves as a key property. When PONA is not available, the Bureau of Mines Correlation Index (BMCI) is used. Other properties like specific gravity, ASTM distillation, viscosity, refractive index. Conradson Carbon, and Bromine Number are also used to characterize the feed. In recent years even nuclear magnetic resonance spectroscopy has been... 

Specific gravity The weight of a material in kg that would occupy one cubic meter under a definite state of conditions. 

A sesquiterpene has been isolated from the essential oil of Cannabis Indica. This may fairly be considered a definite body, as it has been isolated by many different observers and described by them at different times. Valenta first mentions it. Vignolo describes it as a mobile liquid boiling at 256°, of specific gravity -897 at 15°, and slightly laevo-rotatory. Wood, Spivey, and Easterfield give the boiling-point as 258° to 259°, the specific gravity as -898 at 18°, and the rotation as - 8-6°. 

This equation defines the flow coefficient, Cv. Here, SG is the fluid specific gravity (relative to water), pw is the density of water, and hv is the head loss across the valve. The last form of Eq. (10-29) applies only for units of Q in gpm and hv in ft. Although Eq. (10-29) is similar to the flow equation for flow meters, the flow coefficient Cv is not dimensionless, as are the flow meter discharge coefficient and the loss coefficient (Af), but has dimensions of [L3][L/M]1/2. The value of Cv is thus different for each valve and also varies with the valve opening (or stem travel) for a given valve. Values for the valve Cv are determined by the manufacturer from measurements on each valve type. Because they are not dimensionless, the values will depend upon the specific units used for the quantities in Eq. (10-29). More specifically, the normal engineering (inconsistent) units of Cv are gpm/ (psi)1/2. [If the fluid density were included in Eq. (10-29) instead of SG, the dimensions of Cv would be L2, which follows from the inclusion of the effective valve flow area in the definition of Cv]. The reference fluid for the density is water for liquids and air for gases. 

For clarification, it is necessary to understand the basic definitions that are used (1) density is the mass of liquid per unit volume at 15.6°C (60°F), (2) relative density is the ratio of the mass of a given volume of liquid at 15.6°C (60°F) to the mass of an equal volume of pure water at the same temperature, and (3) specific gravity is the same as the relative density and the terms are used interchangeably. 

As the author points out, the sulfuric acid-water system is one of the few examples of a liquid binary system in which certain properties change discontinuously. In this case dsjdp, where s is the specific gravity and p the per cent concentration of H2S04, has discontinuities at certain values of p. The most pronounced correspond to the compositions H2S04—H20 and H2S04—2H20. Mendeleev (102) believes that these characteristic points are connected with the formation in the solutions of definite chemical compounds. The more stable the compound the sharper the discontinuity in the property versus composition. 

Lae resin is very difficultly soluble in alcohol, though, like copal, it may be completaly teken up by this advent. Like most of the other resins, It has a strong affinity for bases, with which it forms definite compounds. Dilute hydrochloric acid and acetic acid dissolve the rosin freely, but not the strong sulphurto acid. Borax solutions with the aid of heat also take it up. The portion soluble in alcohol has a specific gravity of 1-139, IIhvekdokbeN found it to be a compound of several rosins, namely—... 

It is probable that the inconstancy of the results obtained by various investigators for the specific gravity and other characteristics of y-sulphur is due to contamination of the substance examined with other forms of sulphur or with foreign substances. Such a probability is increased by the description of a hydrated form of amorphous sulphur the composition of which points to its being a definite hydrate, S8.H20 this compound is stated to be obtainable by the interaction of hydrogen sulphide and sulphurous acid in aqueous solution.5... 

The relation between specific gravity and concentration gives no definite confirmation of the presence of hydrates in diluted sulphuric acid.6... 

Nickel in a sample from the Colchester (No. 2) Coal Member (Figure 4) is definitely concentrated in the heavier specific gravity fractions. However, the washability curve remains well above the abscissa and does not appear to approach the origin in the cleanest fraction (purest... 

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