Density at reference temperature

Density at reference temperature is obtained from a laboratory analysis of a grab sample. 

The VCF is derived from the temperature measurement using ASTM Table 54 and the density at reference temperature (DENS. REF.). 

Thickness. The traditional definition of thermal conductivity as an intrinsic property of a material where conduction is the only mode of heat transmission is not appHcable to low density materials. Although radiation between parallel surfaces is independent of distance, the measurement of X where radiation is significant requires the introduction of an additional variable, thickness. The thickness effect is observed in materials of low density at ambient temperatures and in materials of higher density at elevated temperatures. It depends on the radiation permeance of the materials, which in turn is influenced by the absorption coefficient and the density. For a cellular plastic material having a density on the order of 10 kg/m, the difference between a 25 and 100 mm thick specimen ranges from 12—15%. This reduces to less than 4% for a density of 48 kg/m. References 23—27 discuss the issue of thickness in more detail. 

Liquid density for most HCs may be found in Fig. 1.2. This chart is a general reference and may be used for general applications that are not critical for discrete defined components. In short, if you don t have a better way of getting liquid density, you can get it from Fig. 1.2. Note that you need to have a standard reference of API gravity reading to predict the HC liquid density at any temperature. 

Several patents dealing with 2ff-naphthol[l,2-6]pyrans also claim the 3H-naphtho[l, 2-6]pyrans and 2//-l-bcnzopyrans as a matter of course. In cases where the 3//-naphtho 2,1 - /> pyrans are of little utility due to low steady-state optical density at room temperature, the references will be discussed under the following section dealing with the 2//-naphlho l,2-/> pyrans. 

The hydrogen-terminated diamond surface also exhibits a p-type conduction. The surface structure, electronic properties, etc. have been extensively studied. This subject has a long history of research, and the readers can refer to Ref. [137] on this topic. Simply summarizing the results obtained so far, the thickness of the Surface conducting layer is 30-100 A, and the hole density at room temperature is approximately 10 /cm. ... 

At = shift coefficient Do = reference temperature density To = reference temperature D = density at temperature of interest T = temperature of interest... 

The literature indicates that for glassy amorphous polymers the best choice of a reference temperature is the glass transition temperature and the density at this temperature. If this temperature is used between the glass transition and the melting point of a polymer it follows that the following equation describes the relationship between the shift coefficient and temperature ... 

Hence, when the specific heat capacity in the two-phase region is plotted as a function of density at constant temperature, the data fall on a straight line, referred to as Yang-Yang plots. We note that complete scaling predicts that both d PaldP and d pJdP contribute to the divergence of the isochoric heat capacity. Since... 

When TTS was originally implemented, the distance that a curve must be shifted in order to transpose it from the temperature of observation T to the reference temperature Tr was determined by the simple empirical curvefitting procedure illustrated above. Pioneering research on this aspect of TTS was carried out by Leaderman (1941, 1943) and Tobolsky (1960), who also modified the procedure to account for the proportionality of modulus to absolute temperature. This has the effect of creating a slight vertical shift in the data. Williams et al. (1955) further modified time-temperature superposition to account for changes in density at different temperatures, which has the... 

The table below gives the weight in grams X 10 of 1 mL of air at 760 mm of mercury pressure and at the temperature indicated. Density in grams per milliliter is the same as the specific gravity referred to water at 4°C as unity. To convert to density referred to air at 70°F as unity, divide the values below by 12,00,... 

In the spring of 1989, it was announced that electrochemists at the University of Utah had produced a sustained nuclear fusion reaction at room temperature, using simple equipment available in any high school laboratory. The process, referred to as cold fusion, consists of loading deuterium into pieces of palladium metal by electrolysis of heavy water, E)20, thereby developing a sufficiently large density of deuterium nuclei in the metal lattice to cause fusion between these nuclei to occur. These results have proven extremely difficult to confirm (20,21). Neutrons usually have not been detected in cold fusion experiments, so that the D-D fusion reaction familiar to nuclear physicists does not seem to be the explanation for the experimental results, which typically involve the release of heat and sometimes gamma rays. 

The values for a single property of two compounds, A and B, are useless unless these values are compared at equal temperature or pressure. Then a deviation from some intermediate value can be determined. If this intermediate value is chosen to be the value of one particular substance, ie. A, the reference substance, both A and B can then be expressed as functions of the reference substance. One very simplistic example is specific gravity where the density of a compound is expressed as the actual density divided by the density of water at 4°C and water is the reference substance. 

Water at 100 °C at atmospheric pressure has a density of 958 kg m " For data at other temperatures and pressures for water and other fluids, full use has to be made of various reference tables. 

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