Composition physical characteristics

In practice, it is not sufficient for an object to have an isotopic composition that cannot be explained by radioactive decay or mass-dependent fractionation effects. The object must also have physical and chemical characteristics making it unlikely to be a product of solar system processes. For example, millimeter- to centimeter-sized refractory inclusions from primitive chondrites have been shown to contain small (parts in 103 to 104) isotopic anomalies in many elements. However, based on the size, composition, physical characteristics, and abundance of the inclusions, it is generally believed that these objects formed within the solar system. They preserve small isotopic anomalies because they did not form from a representative sample of the bulk solar system (see Chapters 7 and 14). So, isotopic anomalies can indicate either that an object is itself presolar or that it formed in the solar system from precursor material that was not fully homogenized in the solar system. As mass spectrometry has become more precise, small isotopic anomalies of the second type have shown up in a wide variety of chondritic materials. As we discuss below and in Chapter 7, these anomalies and bona fide presolar grains can be used as probes of processes in the early solar system. 

ABB-Environmental. 1990. Compilation of data on the composition, physical characteristics and water solubility of fuel products. Prepared for Massachusetts Department of Environmental Protection. Wakefield, Massachusetts. 

The physical properties of all fats and oils, including cottonseed oil, are determined by their chemical composition. Physical characteristics are of practical importance because most applications depend on the melting behavior, solubility, flavor, density, appearance and on other physical properties to provide functionality in finished products. Appropriate analytical and physical evaluation methods are used to measure these attributes for identification, trading, and control purposes. 

Characterizing the interfaee between immobilized biomolecules and a transdueer is critieal for gamering insight into spatial distribution and ordered orientation of bioeatalysts. In particular, the use of immobilization techniques to ineorporate enzymes into hierarehieal eomposite materials (see Chapter 10) and layered arehi-teetures requires detailed information about the composition, physical characteristics, and chemical stracture of the resulting electrode [1]. 

Composition Physical Characteristics and Attributes Medical and Pharmaceutical Applications... 

Intrinsic parameters relating to the materials involved, such as their nature, surface condition and finish. These include bulk properties (e.g. chemical composition, physical characteristics, mechanical properties, hardness) and surface properties (roughness, physico-chemical characteristics). 

Modified ETEE is less dense, tougher, and stiffer and exhibits a higher tensile strength and creep resistance than PTEE, PEA, or EEP resins. It is ductile, and displays in various compositions the characteristic of a nonlinear stress—strain relationship. Typical physical properties of Tef2el products are shown in Table 1 (24,25). Properties such as elongation and flex life depend on crystallinity, which is affected by the rate of crysta11i2ation values depend on fabrication conditions and melt cooling rates. 

In the days of alchemy and the phlogiston theory, no system of nomenclature that would be considered logical ia the 1990s was possible. Names were not based on composition, but on historical association, eg, Glauber s salt for sodium sulfate decahydrate and Epsom salt for magnesium sulfate physical characteristics, eg, spirit of wiae for ethanol, oil of vitriol for sulfuric acid, butter of antimony for antimony trichloride, Hver of sulfur for potassium sulfide, and cream of tartar for potassium hydrogen tartrate or physiological behavior, eg, caustic soda for sodium hydroxide. Some of these common or trivial names persist, especially ia the nonchemical Hterature. Such names were a necessity at the time they were iatroduced because the concept of molecular stmcture had not been developed, and even elemental composition was incomplete or iadeterminate for many substances. 

Fats and fatty oils). For the most part, oil is contained in the kernel or embryo of the seed, though it can also occur in the flesh of the ginkgo fmit and in the endosperm of coconut, palm, and pine nuts. Relative amounts of some fatty acids present in a few types of nuts are given in Table 5. Considerable variations in the percentages of fatty acids have also been reported in both pecan and peanut oils from a variety of sources. (Table 6). (For main physical characteristics and the composition of nut oils, see Fats and fatty oils. 

The value of pigments results from their physical—optical properties. These ate primarily deterrniaed by the pigments physical characteristics (crystal stmcture, particle size and distribution, particle shape, agglomeration, etc) and chemical properties (chemical composition, purity, stabiUty, etc). The two most important physical—optical assets of pigments are the abiUty to color the environment in which they ate dispersed and to make it opaque. 

Characterization. Ceramic bodies are characterized by density, mass, and physical dimensions. Other common techniques employed in characterizing include x-ray diffraction (XRD) and electron or petrographic microscopy to determine crystal species, stmcture, and size (100). Microscopy (qv) can be used to determine chemical constitution, crystal morphology, and pore size and morphology as well. Mercury porosknetry and gas adsorption are used to characterize pore size, pore size distribution, and surface area (100). A variety of techniques can be employed to characterize bulk chemical composition and the physical characteristics of a powder (100,101). 

The physical characteristics of a fat or oil for imitation dairy products are not necessarily dictated by the fat being replaced, but by the composition, processiag methods, and conditions of use of the substitute product. Thus, the selection of the fat or oil is generally developed experimentally. The chemical and physical nature of the components of the system, order of addition, shear iaput, and processiag temperature dictate the final iateractions and the nature of the product. A comparison of the characteristics of milk fat and three different fats that are used ia satisfactory filled and imitation milks are listed ia Table 1 and those that comprise whipped toppiag, ia Table 2. 

The methods just noted tell something about the physical characteristics of atmospheric particulate matter but nothing about its chemical composition. One can seek this kind of information for either individual particles or all particles en masse. Analysis of particles en masse involves analysis of a mixture of particles of many different compounds. How much of... 

Plastic also refers to a material that has a physical characteristic such as plasticity and toughness. The general term commodity plastic, engineering plastic, advanced plastic, advanced reinforced plastic, or advanced plastic composite is used to indicate different performance materials. These terms and others will be reviewed latter in this chapter. Plastics are made into specialty products that have developed into major markets. An example is plastic foams that can provide flexibility to rigidity as well as other desired properties (heat and electrical insulation, toughness, filtration, etc.). 

Table I shows the chemical composition limits of various aluminum alloys presently used for packaging applications (3). In general, these alloys have good corrosion resistance with most foods. However, almost without exception, processed foods require inside enameled containers to maintain an acceptable shelf life (4, 5). Moreover, when flexible foil packages are used for thermally processed foods, the foil is laminated to plastic materials that protect it from direct contact with the food and also provide heat sealability as well as other physical characteristics (6,7).

The combination of physical and chemical characteristics of nodules make impossible the application of methods of physical beneficiation such as flotation and magnetic separation to produce concentrates of valuable metals, and so chemical processing must be used. Their processing also tends to be much more energy-intensive, vis-a-vis that of conventional land-based ores. Deep-sea manganese nodules are quite unlike any terrestrial ores, both with respect to their physical characteristics and to their mineralogical and chemical compositions new processes are, therefore, required. 

Factors that may be considered in selecting a tier include the physical characteristics of the facility and surrounding terrain, the anticipated waste compositions and feed rates, and the level of resources available for conducting the analysis. The main distinction between the tiers is the focal... 

Any two samples of a particular mineral, whatever their source or place of origin, have the same basic composition and characteristic crystal structure moreover, no two different minerals have identical chemical composition and crystal structure (see Textboxes 8 and 21). Quartz, for example, is a common and abundant mineral composed of silicon dioxide, a compound that occurs naturally not only as quartz but also in other crystal structures, known as polymorphs (polymorphs are minerals that have the same chemical composition but different crystal structure), some of which, listed in Table 23, have been used for a variety of purposes. The crystal structure, which is essential for the characterization of solid materials, is just one of a wide range of physical properties, that is, properties not involving chemical differences, which provide convenient criteria for characterizing and identifying solids. 

Turner, W. E. S. (1959), Studies in ancient glasses and glass-making processes (VI) The composition and physical characteristics of the glass of the Portland vase, /. Soc. Glass Technol. 43, T262-T284. 

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