Subject physical characteristics

Spices are natural agricultural products and exhibit a range of variations of many specific characteristics. The most important quaUty assessment is the subjective physical observation of the whole or ground spice by an expert. The macroscopic and microscopic examination of spice is the criterion for the continued analysis of the product to determine adherance to specifications. 

Samples of particulate matter can be subjected to many of the above analytical techniques in chemical characterization. The following methods are, however, particularly applicable to analysis of physical characteristics of particulate matter isolated from air sampling. 

Returning now to the subject of the chapter, in addition to appropriate retentive characteristics, a potential stationary phase must have other key physical characteristics before it can be considered suitable for use in LC. It is extremely important that the stationary phase is completely insoluble (or virtually so) in all solvents that are likely to be used as a mobile phase. Furthermore, it must be insensitive to changes in pH and be capable of assuming the range of interactive characteristics that are necessary for the retention of all types of solutes. In addition, the material must be available as solid particles a few microns in diameter, so that it can be packed into a column and at the same time be mechanically strong enough to sustain bed pressures of 6,000 p.s.i. or more. It is clear that the need for versatile interactive characteristics, virtually universal solvent insolubility together with other critical physical characteristics severely restricts the choice of materials suitable for LC stationary phases. 

The terms race, ethnicity, and minority are also used in this chapter. Race refers to a group that is socially defined on the basis of physical characteristics. Ethnicity refers to a shared culture and lifestyle, especially as reflected in language, folkways, religious and other institutional forms, material culture such as clothing and food, and cultural products such as music, literature, and art. Finally, the term minority group refers to a part of a population differing from others in some characteristics, which often subject them to differential treatment (Byrd and Clayton, 2002 Van de Berghe, 1967). 

As briefly mentioned, the occurrence of sediments in sewers is closely related to the hydraulics and physical process characteristics and the properties of the solids. This text does not include a quantitative description of the physical processes in sewers, such as sedimentation, deposition and erosion, and the corresponding physical characteristics of sewer solids. A great number of publications and textbooks address these subjects. A comprehensive description with a broad range of literature references can be found in Ashley and Verbanck (1998). Other important publications in this respect are found in Ashley (1996), Hvitved-Jacobsen et al. (1995) and Hvitved-Jacobsen (1998). Perspectives and relations to the chemical and biological sewer processes are outlined in Ashley etal. (1999). 

The selection of the type of spray nozzles should be made with proper consideration given to such factors as discharge characteristics, physical characteristics of the hazard involved, water quality and potential for pluggage, ambient conditions, material likely to be burning, and the design objectives of the system. Also, some spray nozzles are more subject to pluggage than other ones. 

Clearly the macroporous polymers are the only solids that have the physical characteristics useful for gravity flow columns. This conclusion is frequently not considered or discussed. With respect to the polymers listed in Table I, the most useful are those with the highest surface areas however, these are subject to the caveat about pore size discussed next. 

Human exposure refers to the individual contact (not uptake) with a pollutant concentration. It is, then, important to distinguish between concentration and exposure. According to Sexton and Ryan [9] concentration is a physical characteristic of the environment at a certain place and time (amount of material per unit volume of air), while the term exposure stands for the interaction between the environment and a living subject. For exposure to take place two events need to occur simultaneously pollution concentration at a particular time and place, and the presence of a person in that same place and time. Thus exposure has the dimension of (mass) x (time)/(volume) . 

It is certainly not by chance that Barriol s first research, in collaboration with Pierre Donzelot, dealt with the Raman effect. Lespieau had been one of the first who had studied, often with Maurice Bourguel, the Raman effect, [9] in relation to chemical constitution. [10] Donzelot did some research on the same subject with Charles Prevost, another student of Lespieau, when Prevost was a professor of chemistry at the Nancy Faculte de Pharmacie. At the very same time Barriol also was around. A note to the Academic, des Sciences, concerning the relation between Raman frequencies and interatomic distances, by Donzelot and Barriol, was presented by Lespieau and concluded It seems that the interatomic distance constitutes an essential characteristic of a molecule, around which one can group the properties, not only those related to the Raman effect, but also manyfold physical characteristics. [11]... 

Polyimides have also been the subject of many review compilations of papers and continue to be the focus of many conferences around the world [28-33]. Having various chemical forms, including isoimides, polyimides have found use in a vast array of applications that in some cases, due to their superior physical characteristics have displaced epoxies, for example, as matrix polymers in aerospace vehicles. 

Food Starch, Modified, usually occurs as white or nearly white powders as intact granules and if pregelatinized (that is, subjected to heat treatment in the presence of water), as flakes, amorphous powders, or coarse particles. Modified food starches are products of the treatment of any of several grain-or root-based native starches (for example, com, sorghum, wheat, potato, tapioca, and sago), with small amounts of certain chemical agents, which modify the physical characteristics of the native starches to produce desirable properties. 

The fourth physical characteristic of Chinese silks, a soft "hand , we feel is the result of calendering, which is a characteristic mechanical method for finishing silks in China (Figure 3). This process involves a stone base plate, a wooden roller, and a heavy rocking stone. The silk fabric is placed on a roller and subjected to intense pressure as a workman rocks back and forth on a rocking stone. This process leaves an unmistakable sheen and soft clinging hand that can distinguish Chinese silks from Western ones. 

In drug preparations, sensitivity is not a particular problem as there is always sufficient of the active constituent present. Suitable extraction procedures should be carried out and each fraction should then be subjected to chromatographic analysis. The mass spectra, together with the appropriate retention parameters, may then be used for identification purposes. In many cases mass spectrometric analysis is undertaken as confirmation of an identification based on the physical characteristics such as size, colour, markings, etc., of the tablet or capsule. Mass spectrometry may be used not only to identify the major components but also the trace impurities. This information may be used for quality control purposes, and may enable the route of manufacture of certain drugs to be determined. 

The following revised set of tables of the physical characteristics of the methyl ethers of the aldopentoses and rhamnose and fucose (and their derivatives) replaces those of R. A. Laidlaw and E. G. V. Percival, Advances in Carbohydrate Chem., 7, 1 (1952), and brings the subject up to date. 

Naturally occurring talc is mined and pulverized before being subjected to flotation processes to remove various impurities such as asbestos (tremolite) carbon dolomite iron oxide and various other magnesium and carbonate minerals. Following this process, the talc is finely powdered, treated with dilute hydrochloric acid, washed with water, and then dried. The processing variables of agglomerated talc strongly influence its physical characteristics. " ... 

This study of a test pavement using recycled HMA, in which the penetration of the old bitumen had been adjusted using new HMA, confirmed the durability of such a pavement and showed that it could maintain a comparatively good level of utility even after 15 years and 3 months of use. Also, with respect to the physical properties, we have found that the bitumen deterioration of layers of the HMA subject for public use was comparatively small and that the repeated reuse of pavement is indeed possible. Such a high evaluation of pavement recycling from the viewpoint of both utility and physical characteristics should broaden the possibilities for expansion into re-recycling. 

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