Volatiles content

The volatiles contents of product chars decreased from ca 25—16% with temperature. Char (lower) heating values, on the other hand, increased from ca 26.75 MJ /kg (11,500 Btu/lb) to 29.5 MJ /kg (12,700 Btu/lb) with temperature. Chars in this range of heating values are suitable for boiler fuel apphcation and the low sulfur content (about equal to that of the starting coal) permits direct combustion. These char products, however, are pyrophoric and require special handling in storage and transportation systems. 

Analysis of refined germanium products is done in a wide variety of ways, including several methods that have become ASTM standards (47). Electronic-grade Ge02 is analyzed using an emission spectrograph to determine its spectrographic purity. Its volatile content is measured in accord with ASTM F5 and its bulk density with F6. Other ASTM standards cover the preparation of a metal biHet from a sample of the oxide (F27), and the determination of the conductivity type (F42) and resistivity (F43) of the biHet. 

The volatile content of the treated paper is important because moisture acts as a temporary plasticizer to promote resin flow during early stages of pressing (9). Dynamic mechanical analysis of the treated paper is a very useful means to study the initial flow stages of a resin and the cure time required to complete cross-linking (10). 

Commercial polystyrenes are normally rather pure polymers. The amount of styrene, ethylbenzene, styrene dimers and trimers, and other hydrocarbons is minimized by effective devolatilization or by the use of chemical initiators (33). Polystyrenes with low overall volatiles content have relatively high heat-deformation temperatures. The very low content of monomer and other solvents, eg, ethylbenzene, in PS is desirable in the packaging of food. The negligible level of extraction of organic materials from PS is of cmcial importance in this appHcation. 

Anthracite. Anthracite is preferred to other forms of coal (qv) in the manufacture of carbon products because of its high carbon-to-hydrogen ratio, its low volatile content, and its more ordered stmcture. It is commonly added to carbon mixes used for fabricating metallurgical carbon products to improve specific properties and reduce cost. Anthracite is used in mix compositions for producing carbon electrodes, stmctural brick, blocks for cathodes in aluminum manufacture, and in carbon blocks and brick used for blast furnace linings. 

A convenient method for assessing the extent of surface oxidation is the measurement of volatile content. This standard method measures the weight loss of the evolved gases on heating up to 950°C in an inert atmosphere. The composition of these gases consists of three principal components hydrogen, carbon monoxide, and carbon dioxide. The volatile content of normal furnace blacks is under 1.5%, and the volatile content of oxidized special grades is 2.0 to 9.5%. 

The characteristics of roUer process impingement blacks are basically similar to those of channel blacks. They have an acidic pH, a volatile content of about 5%, surface area of about 100 m /g, and an average particle diameter of 10—30 nm. The smaller particle size grades are used as color (pigment) blacks, and the 30-nm grade is used in mbber. 

Regime 1. If the tank is initially saturated (usually pressurized with volatile contents) there is no padding gas contributing noncon-densables, so Tj, = 1 and Ot, = 0. In this case, a discharge in the liquid space is a flashing hquid. 

To reduce emissions from fuel-burning sources, one can limit the sulfur, ash, or volatile content of fuels. A listing of such limitations as they existed in 1974 is given in Martin and Stem (see Suggested Reading). 

Methods of preparation of the laminates depend on the partieular grade of polyimide resin used but in one process the polyimide precursor is dissolved in acetone and this solution is used to impregnate the glass or carbon fibre and thus produce a pre-preg . The pre-preg is dried and then pre-cured at about 200°C for about 3 hours. This operation reduces the volatile content and also modifies the flow properties to make them more suitable for the subsequent... 

The sliced sheet will still contain large quantities of alcohol and it is necessary to season the sheet at elevated temperatures. This may only take three days at 49°C for 0.010 in (0.025 cm) thick sheet but will take about 56 days for 1 in (2.5 cm) thick blocks. The removal of alcohol, as might be expected, is accompanied by considerable shrinkage. Fully seasoned sheet has a volatile content of 2%, the bulk of which is water but there is some residual alcohol. The sheet may be fully polished by heating in a press between glazed plates under pressure for a few minutes. Because the material is thermoplastic it is necessary to cool it before removal from the press. 

Volatile content, water, density, volume and weight of surface coatings 24, 24A... 

Operational differences in the analytical methods used for determining the heating value of the volatile content. 

A soft coal with a high volatile content. 

Johnson MC, Anderson AT, Rntherford MJ (1994) Pre-emptive volatile contents of magmas. Rev Min... 

Figure 1. Solidus as a function of pressure and temperature for diy peridotite, wet peridotite, pyroxenite and eclogite. This diagram illustrates the range in solidus temperatures potentially found in the intraplate tectonic setting where compositional differences and differences in volatile contents are expected compared with the mid-ocean ridge (dry peridotite).

Although these considerations are theoretically reasonable, there are very few case studies where these complexities have been explicitly demonstrated. However, it is important to note that several studies have shown that source heterogeneities could play a role in producing the observed U-Th disequilibria (Hirschmann et al. 1999, Turner et al. 1997). It has been argued in the case of the Azores region that the volatile content in the... 

Bottled samples had been supplied 3 years previously packed in vermiculite in sealed cans. The caps had disintegrated in storage allowing the volatile contents to escape into the external can. When this was pierced, a jet of isocyanate sprayed out uncontrollably. Improved caps are now used for this material [1]. 

Storax resin is extracted from Liquidambar orientalis (Hammamelidiaceae) and Altingia and its major components are cinnamyl cinnamate and 3-phenylpropanyl cinnamate, with significant amounts of benzoic and cinnamic acids, and 3-phenylpropanol and cinnamyl alcohols [130,131]. The volatile content is very low and triterpenes (oleanonic and 3-epioleanolic acids and liquid ambronovic acid) have also been observed [130,132]. 

Thermogravimetry (TG) is a measure of the thermally induced weight loss of a material as a function of the applied temperature [45]. Thermogravimetric analysis is restricted to studies that involve either a mass gain or loss, and it is most commonly used to study desolvation processes and compound decomposition. The major use of TG analysis is in the quantitative determination of the total volatile content of a solid. When a solid can decompose by means of several... 

The crystals of halcinonide are not solvated with water, based on a total volatile content of 0.3% obtained by thermal gravimetric analysis, a correct elemental analysis, and a loss-on-drying value of 0.6% (of. section 4.1, Elemental and Inorganic Analyses). 

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