Apparent specific volumes

The density of a substance depends on its physical state. Solids are usually more dense than liquids (ice and water are obvious exceptions). Thus, the density depends on the type of packing of molecules in a crystal or a liquid. If the density is measured in solution, the relation of the molecules of the solvent to the molecule of solute may influence density. In Table III are recorded densities obtained by several different methods. The variable values reflect not only technical problems of measuring density, but also the differences obtained when crystal structure differs and when the molecule is in solution. 

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The apparent specific volume was determined from the density measurements via the relation [9]... 

Otagiri et al. (22) used model peptides composed of arginine, proline, and phenylalanine to ascertain the relationship between bitter flavor and chemical structure. They reported that the presence of the hydrophobic amino acid at the C terminus and the basic amino acid at the N terminus brought about an increase in the bitterness of di- and tripeptides. They further noted a strong bitter taste when arginine was located next to proline and a synergistic effect in the peptides (Arg)r(Pro) ,-(Phe) (/ = 1,2 m, n = 1, 3) as the number of amino acids increased. Birch and Kemp (23) related the apparent specific volume of amino acids to taste. 

Figure 58. Effect of Moisture on Heat Conductivity, Apparent Specific Volume, and Diffusivity of Quartz Whose Size-Distribution Is Given in Table 37.

Average diameter of particle (mm) Apparent specific volume (cc/g) Period required for rise of 6.3 deg C at 5 cm from heat source (min) Conductivity (cal per sq cm per sec per deg change in temperature gradient) Diffusivity (rate of rise of temperature at 5 cm from heat source per deg change in temperature gradient)... 

The agreement between the two expressions is good at the lower temperatures, and the differences at higher temperatures are about the same value as the coefficient of expansion of glass. Thus at 200° C. the second equation gives the specific volume as 0-6180 e.c. per gram. Without the correction for expansion of glass the apparent specific volume becomes 0-621 c.c. 

In swine, following intra-aortic administration, the disappearance of parent T-2 toxin followed a two compartment open model with mean elimination phase half-life of 13.8 min and mean apparent specific volume of distribution of0.3661/kg (Beasley et al, 1986). Parent T-2 toxin was not detected in plasma, urine, or liver but was transiently present in lymphoid tissues. T-2 toxin and metabolites were eliminated as glucuronide conjugates into bde, undergoing deconjugation in the intestinal tract by microbial action and then underwent enterohepatic recirculation (Corley et al, 1985). 

The volume changes on mixing non-aqueous liquids, the densities of mixed liquids, of solutions of non-polar solutes in non-polar solvents, and the changes of total volume on the solution of solid salts in water, noticed at an early period and much investigated, can only be mentioned here some aspects of these will be dealt with later. Hyde found the densities of solutions of jp-nitrotoluene in carbon disulphide smaller than the density of either component, but the anomaly disappears if the p-nitrotoluene is supposed to be in the liquid state. Biron found that the volume change on mixing two liquids was Av=kx( —x where x , (1— ) are the mol fractions, and he investigated the effect of pressure on the value of Av. The apparent specific volume of alcohol in aqueous mixtures was determined by Brown, lo... 

Wood meal is used for industrial explosives and also as an anticaking agent etc. It is q,uite cheap and does not disturb the colour of flames, and is used mainly for lance compositions, A standard test indicated less than ly moisture 6.5 8.5 cc/g apparent specific volume 7% of the meal passes 30 mesh less than lA% ashtThe Ind. Exp.S, J. Handbook of industrial explosives, p,215(1966)1. 

This is used for white smoke composition in combination with zinc dust and hexachloroethane, It seems that the higher the purity is, the whiter the smoke colour is. The smoke composition is generally packed in a tin case, and the apparent specific volume is important in manufacture if it is too small the can is not filled and if it is too large, the case cannot be filled with the amount defined in the specification. The apparent specific gravity of this material on the market lies between about 0.5 hg and 1.0 kg per litre. 

Birch GG, Haywood KA, Hanniffy GG, et al. Apparent specific volumes and tastes of cyclamates, other sulfamates, saccharins and acesulfame sweeteners. Food Chemistry 2004 84 429-435. 

One of the approaches found most suitable to explain the sensorial properties of sweet, bitter, and sweet-bitter substances proves to be the physico-chemical approach especially as concerns hydration and surface properties (DeSimone and Fleck, 1980 Funasaki et al., 1996 Fimasaki et al., 1999 Mathlouthi and Hutteau, 1999). Thus, solution properties of sweet and bitter molecules were found informative on their type of hydration (hydrophobic or hydrophilic) and on the extent of the hydration layer (Fiutteau et al., 2003). Physico-chemical properties (intrinsic viscosity, apparent specific volume, and surface tension) and NMR relaxation rates of the aqueous solutions of sucrose, caffeine, and sucrose-caffeine mixtures were used in the interpretation of the taste modalities of these molecules and to explain the inhibition of caffeine bitterness by sucrose (Aroulmoji et al., 2001). Caffeine molecules were found to form an adsorption layer whereas sucrose induces a desorption layer at the air/water interface. The adsorption of caffeine gradually increases with concentration and is delayed when sucrose is added in the caffeine solution (Aroulmoji et al., 2004). 

As an example of the above, the apparent specific volume is given by... 

As can be expected from Eq. [3.2], the total pore volume was experimentally found to be linearly proportional to the (apparent) specific volume... 

McCabe and Fisher (1965) have measured the excluded volume of protein molecules by means of differential spectroscopy in the near-infrared region. The excluded specific volumes of bovine serum albumin and lysozyme were found to be 0.74 ml/g and 0.68 ml/g, respectively, values which are close to the values of apparent specific volume reported in the literature (Dayhoff et al., 1952 Sophianopoulos et al, 1962). The authors suggested that excluded specific volume as measured by their method is closely associated with the partial specific volume of the protein molecule. 

Apparent specific volume of mixed micelle by pycnometry (20 C). 

J able IV lists some apparent specific volumes (V/MW D for glucose, maltose, maltodextrin (DE=17) and -cyclodextrin at different... 

Kinally, Table iV shows a high apparent sp>ecific volume for sorbitol. This must be due to lack of cyclic structure rather than lack of an anomeric centre in the molecule because the apparent specific volume of myoinositol is smaller than that of the sugars, i.e. 0.560 c m g (11). 

Similarly, based on density and sound velocity measurements, Parke and Birch [88] reported apparent specific volume and apparent specific isenttopic compressibility curves for the ethanol/water mixture. They observed a shallow minimum in the apparent specific isentropic compressibility curves at Xi 0.05 and an increase afterwards, which generally conforms to the situation presented in Figure 6.5. 

The apparent specific volume, V wUch is foe revase of the bulk daisity, was measured by mercury pycnometry. After placing a fiiam sample of wei w, in a pycnometer, it is completely filled with mercury and weighed (w, ). F, is calculated arxxmding to foe expression wh e wj is foe weight of the pycnometer filled with... 

The function f(m T) = - dCp ldP)T,m = T(d VldT )p as showed by Hepler [124] plays an important role in understanding the effect of dissolved solutes on the stracture of water. Similar conclusions were reached by Neal and Goring [125] who used instead of the first and second derivatives of total volume, the derivatives of the apparent specific volume... 

The decrease in apparent specific volume of gelatin accompanjdng gelation should result in a shift of the process toward gelation at high pressures. An effect of this sort has been observed by Marsland and Brown (1942), who found that the viscosity of a 4% solution increased by a factor of 10 when the confining pressure was increased to 8000 lbs. per sq. in. 

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