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Chemical refining modifications

There are two principal continuous refining processes physical refining and chemical refining. Three other continuous refining techniques used in the sunflower oil industry are improved modifications of the above processes. These include the cold chemical refining process, the modified chemical refining process and the modified physical refining process. [Pg.148]

Chemical structure modifications which enhance activity and refine specificity will be followed up using medicinal chemistry methods, relating structures of compounds to activity in certain assays. These exercises will result in the definition of a quantitative structure activity relationship (SAR) for the series of compounds active in the assays. [Pg.44]

Approximately 50—55% of the product from a coal-tar refinery is pitch and another 30% is creosote. The remaining 15—20% is the chemical oil, about half of which is naphthalene. Creosote is used as a feedstock for production of carbon black and as a wood preservative. Because of modifications to modem coking processes, tar acids such as phenol and cresyUc acids are contained in coal tar in lower quantity than in the past. To achieve economies of scale, these tar acids are removed from cmde coal tar with a caustic wash and sent to a central processing plant where materials from a number of refiners are combined for recovery. [Pg.162]

EINECS is a closed list containing 100,106 entries and counts for about 99% of the chemicals volume on the market. EINECS include chemical substances produced from natural products by chemical modifications or purification, such as metals, minerals, cement, refined oil, and gas substances produced from animals and plants active substances of pesticides, medicaments, fertilizers, and cosmetic products food additives a few natural polymers and some waste and by-products. They can be mixtures of different chemicals occurring namrally or as an unintentional result of the production process. [Pg.35]

Fast deactivation rates due to coking and the limited hydrothermal stability of pillared clays have probably retarded the commercial development of these new type of catalysts and prevented (to date) their acceptance by chemical producers and refiners. However, there is a large economic incentive justifying efforts to convert inexpensive (i.e. 40-100/ton) smectites into commercially viable (pillared clay) catalysts (56). Therefore, it is believed that work on the chemical modification of natural (and synthetic) clays, and work on the preparation and characterization of new pillared clays with improved hydrothermal stability are, and will remain, areas of interest to the academic community, as well as to researchers in industrial laboratories (56). [Pg.14]

Careful examination of (2IF0 — IFCI) and (IF, I —IF, I) maps at each refinement step led to the conclusion that no bound ligand was present. There was no continuous positive electron density present near the ligand-binding site as identified in both P2 (Jones, et al., 1988) and IFABP (Sacchettini et al., 1989a). The absence of bound fatty acid in crystalline ALBP is consistent with the chemical modification experiment which indicates ALBP purified from E. coli is devoid of fatty acid (Xu et al., 1991). The final refined coordinate list includes 1017 protein atoms and 69 water molecules. [Pg.183]

The most important distinction between the two structures is that only the helical model is compatible with all of the published structural data, including results obtained from limited proteolysis [81,83], chemical cross-linking [83], analytical ultracentrifugation [81], and mutant complementation [84,85]. Although the double helix provides a useful model with good predictive power, it will no doubt be subjected to further investigation by, for example, atomic force microscopy or X-ray crystallography. Such experiments should refine the structural information on PKSs, and point the way toward the productive modification and immobilization of the synthases. [Pg.464]

The above discussions have shown how selected analytical techniques can be applied to vastly different proteins to solve a myriad of problems. These include routine assays amino acid and sequencing analyses specialized techniques FAB-MS and IEF conventional techniques refined to improve their utility reversed-phase HPLC using different pHs, organic modifiers, and temperatures and chemical and enzymatic modifications. The latter two procedures have been shown to be effective not only in elucidating primary structure but also in probing the conformation of proteins. [Pg.110]

Application of Chemical Modification for Refining Proteins Yeast Proteins... [Pg.177]

The selection and chemical modification of the current generation of chemically and physically robust stationary phases with narrower particle and pore size distributions has been based on the developmental effort that has occurred over the past 20 years. Initially chemically modified, deformable polymeric gels were used, such as the crosslinked agaroses, dextrans, or acrylate-based copolymers, but more recently various classes of highly refined type I and type II silicas and other ceramic materials, or new classes of controlled porosity polymeric organic materials have found increasing application. [Pg.117]

In relation to food proteins, chemical modification has been studied for several purposes, i.e. to block reactive groups involved in deteriorative reactions to improve nutritional properties, to enhance digestibility to impart thermal stability to modify physicochemical properties to facilitate study of structure-function relationships and to facilitate separation, processing and refining of proteins (1,2,10,19,20,24). [Pg.42]

To achieve success as protein ingredients for food formulation and fabrication, novel proteins should possess a range of functional properties. Frequently during extraction, refining and drying, plant and yeast proteins, intended for food uses, become denatured or altered and subsequently display poor functional properties which render them of limited use. Chemical modification provides a feasible method for improving the functional properties of plant and yeast proteins and potentially may make it possible to tailor proteins with very specific functional properties. In this review the information on modified plant proteins is reviewed and the use of succinylation for the recovery of yeast proteins with low nucleic acid is described. [Pg.60]

Today, HIPS is produced by two basic variants the batch process and the continuous process. Pre-polymerization, i.e. the polymerization phase up to completion of phase inversion, is identical in the two process variants. After completion of the pre-polymerization, the polymerization is continued in suspension in the batch process and in solution in the continuous process. The batch process is, therefore, also referred to as the bulk suspension process and the continuous variant as the solution process. The continuous process is a refinement of the original I.G. Farben process for standard polystyrene, which The Dow Chemical Company has adapted to the needs of rubber-containing styrene solutions. A number of modifications are now practiced. [Pg.268]


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See also in sourсe #XX -- [ Pg.389 ]




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