Chemical Comparability

Exotic materials are less likely to be used in the constmction of hopper cars than in tank cars because of the lower chemical aggressiveness of soHd chemicals compared to that of Hquids and gases. 

The detergent industry is the largest user of industrial enzymes. The starch industry, the first significant user of enzymes, developed special symps that could not be made by means of conventional chemical hydrolysis. These were the first products made entirely by enzymatic processes. Materials such as textiles and leather can be produced in a more rational way when using enzyme technology. Eoodstuffs and components of animal feed can be produced by enzymatic processes that require less energy, less equipment, or fewer chemicals compared with traditional techniques. 

The principal advantages of glass linings are the increased size and mechanical strength that are possible compared with all-glass equipment, and the flexibility of operation with different chemicals compared with all-metal equipment. The increased heat transmission, in comparison with glass equipment, can also be an advantage. 

Howes, M. A. H., IIT Research Institute Hughes, R., Illinois State Geological Survey Hughes, T. R., Chevron Research Company Hunt, A. J., Lawrence Berkeley Laboratory Irving, J. P., Chevron Oil Field Research Co. Jacques, D., Exxon Chemical Comparer Jefcoat, I. A., University of Alabama Jezl, J. L., Amoco Chemicals Company Jerome, J., Northwestern University... 

The other extraction method is an SEE procedure, which is a much easier procedure for extracting the nonpolar chemicals compared with polar chemicals. 

As can be seen, the cellulolytic action of the fungus has indeed brought about a two-fold increase in the yield of extractable lignin. The native and enzymatically liberated lignins were then chemically compared and found to be identical in all respects examined (Table 4). 

Matthew EJ, Spalding JW, Tennant RW (1993) Transformation of BALB/c-3T3 cells via transformation responses of 168 chemicals compared with mutagenicity in salmonella and carcinogenicity in rodent bioassays. Environ Health Perspect 101 347 182... 

The structure of the 3-oxo derivative 65 was determined by high resolution mass spectrometry, which demonstrated that a single oxygen atom had been incorporated into the alkaloid skeleton. Peaks in the mass spectrum at mte 174 and 188 provided evidence that the additional oxygen atom was not in the dihydroindole portion of the molecule, while a peak at mte 138 supported the presence of an oxygenated piperdine ring. This metabolite was also chemically compared with authentic oxodihydrovindoline derivatives previously prepared and provided for comparison by J. P. Kutney. 

Muir, C.K. (1985). Opacity of bovine cornea in vitro induced by surfactants and industrial chemicals compared with ocular irritancy in vivo. Toxicol. Lett. 24 157-162. 

A susceptible population is defined as one which will exhibit a different or enhanced response to a chemical compared to most persons exposed to the same level of exposure. Reasons may include genetic makeup, age, health and nutritional status, and exposure to other toxic substances (e g., cigarette smoke). For this chemical, these parameters may result in reduced detoxification or excretion of 3,3 -dichloro-benzidine, or compromised function of target organs affected by 3,3 -dichlorobenzidine. Populations who are at greater risk due to their unusually high exposure to 3,3 -dichlorobenzidine are discussed in Section 5.6, Populations With Potentially High Exposure. 

Ames, B. N., Profet, M., and Gold, L. S. (1990). Nature s chemicals and synthetic chemicals comparative toxicology. Proceedings of the National Academy of Sciences of the USA 87, 7782-7786. 

Amoco Amoco Chemicals Compare, a subsidiary of Amoco Corporation, formerly Standard Oil Company (IN), is best known in the chemicals industry for its modification of the Mid-Century process for making pure teiephthalic acid. /r-Xylene in acetic acid solution is oxidized with air at high temperature and pressure. Small amoimts of manganese, cobalt, and bromide are used as catalysts. The modification allows the use of teiephthahc acid, rather than dimethyl terephthalate, for making fiber. The process can also be used for oxidizing other methylbenzenes and methylnaphthalenes to aromatic carboxyhc acids. See also Maruzen. 

Aquaclaus A modification of the Claus process in which hydrogen sulfide is removed from water by reaction with sulfur dioxide. Developed by Stauffer Chemical Comparer and operated by the Heflin Oil Company, in Queen City, TX. 

Carus A process for making potassinm permanganate by reacting manganese dioxide with molten potassium hydroxide, in air. Invented by M. B. Carus in 1958 and operated by the Carus Chemical Comparer at La Salle, IL. 

CCOP [Chlorine-catalyzed oxidative pyrolysis] A process for converting methane into a mixture of ethylene and acetylene. Invented by the Illinois Institute of Technology, Chicago, and under development by Dow Chemical Compare in 1991. 

Climax A process for making sodium sulfate from sulfuric acid and sodium chloride. Sulfuric acid is sprayed onto a hot fluidized bed of sodium chloride. The products are granular sodium sulfate and hydrogen chloride gas. Invented in 1967 by C. K. Cnrtis later developed and commercialized by C. W. Cannon at the Climax Chemical Comparer at Midland, NM, in the 1970s. Midland was a favorable location becanse of the proximity of mineral salt and snUur from petrolenm and the availability of cheap transport of the prodnct from the site. French Patent 1,549,938. 

GTG [gas to gasoline] A process for converting natural gas to gasohne by oxidative coupling. Ethylene, formed initially, is oligomerized to a gasohne-like distillate over a zeolite catalyst. Under development by the Arco Chemical Comparer in 1988. 

Ruhr Chemie Ruhr Chemie was an important German chemical comparer in the 1930s and 1940s. It was perhaps best known for its process for making acetylene by pyrolyzing hydrocarbons. See also WuUf. 

For clean gaseous effluents, such as those from nitric acid plants, the preferred catalyst is mordenite. For flue-gases containing fly ash, the preferred catalyst is titania-vanadia. The process was developed in Japan in the mid-1970s by a consortium of Hitachi, Babcock-Hitachi, and the Mitsubishi Chemical Comparer, and by the Sakai Chemical Industry Company. It is widely used in power statiorrs in Japan and Germarty. See also SNCR. 

Sulfa-scrub A process for removing low concentrations of hydrogen sulfide from gas streams by reaction with hexahydrotriazine. The product is water-soluble, non-corosive, and non-hazardous. Developed by the Quaker Petroleum Chemical Comparer in 1991. 

The buyer of a chemical lacks in-depth knowledge on the efficient application of the chemical in use. This leads to excessive use (i.e. over-consumption) of the chemical compared to a situation where the user is fully informed. Now the producer transfers knowledge to the user, which concurrently increases the efficiency of the chemical s application. All else being equal, this lowers the user s demand of chemicals. In a competitive market this does not change the price of the chemical and thus the profit of the seller decreases. We therefore maintain that the traditional sales concept poses no incentives to fully inform the users on the properties of the traded chemicals. May this change under the REACH initiative ... 

One of the main results of implementing Chemical Leasing for the producer is having free capacities to produce alternative products instead of the one the volume of which is being reduced by the implementation of Chemical Leasing. This effect is probably more important for batch processes to produce chemicals compared to continuous processes because of the much higher efforts to change the process of the latter. But of course it is possible to compensate the reduced volume of a continuous-process chemical by new customers. 

B. N. Ames, M. Profet, and L. S. Gold, Nature s Chemicals and Synthetic Chemicals Comparative Toxicology, Proc. Natl. Acad. Sci. U.S.A. 87 (1990) 7782-86 B. N. Ames, M. Profet, and L. S. Gold, Dietary Pesticides 99.99 Percent All Natural, ibid., 7777-81 L. S. Gold, T. H. Slone, and B. N. Ames, Prioritization of Possible Carcinogenic Hazards in Food, in D. Tennant, ed., Food Chemical Risk Analysis (London Chapman Hall, 1997), pp. 267-95. 

Transformation responses of 168 chemicals compared with mutagenicity in salmonella and... 

Packed columns contain an inert and stable porous support on which the stationary phase can be impregnated or bound (varying between 3 to 25%). The solid support is made of spheres of approximately 0.2 mm in diameter, obtained from diatomites, silicate fossils (such as kieselguhr, tripoli) whose skeleton is chemically comparable to amorphous silica. These materials, which have a specific surface area ranging from 2 to 8 m2/g, have been commercialised by several companies such as Johns Manville, under the name of Chromosorb , and are used universally. Other synthetic materials have been developed such as Spherosil , made of small silica beads. All of these supports have a chemical reactivity comparable to silica gel because of the presence of silanol groups. 

Indeed, not much capital is needed to manufacture specialty chemicals compared with what is required for commodity chemicals. The development of new products is both quicker and less costly than it would be to find new processes for large-volume products or to bring to the market an original active principle for an ethical drug. 

B. N. Ames, M. Profet, and L. S. Gold, Proc. Natl. Acad. Sci. USA, 87,7782 (1990). Nature s Chemicals and Synthetic Chemicals Comparative Toxicology. 

In general, PBBs show an unusual chemical stability and resistance to acids, bases, heat, reduction and oxidation. PBBs are chemically comparable to the PCBs. However, chlorine atoms have a stronger association to polybiphenyl than bromine atoms [2]. Unlike PCBs, the reactivity of PBBs has not been well studied and documented in the literature [11]. Like PCBs, their chemical stability is dependent, in part, on the degree of bromination and the specific substitution patterns [12]. 

The classification of individual substances should be based on the total weight of evidence available, using expert judgement. In those instances where a single well-conducted test is used for classification, it should provide clear and unambiguously positive results. If new, well validated, tests arise these may also be used in the total weight of evidence to be considered. The relevance of the route of exposure used in the study of the chemical compared to the route of human exposure should also be taken into account. 

Other molar weathering ratios can be devised to reflect leaching (Ba/Sr), oxidation (Fe0/Fe203), calcification (CaO + MgO/AlaOs), and salinization (Na20/K20). Two of these ratios reflect differential solubility of chemically comparable elements, but calcification ratio quantifies the accumulation of pedogenic calcite and dolomite, and the ratio of iron of different valence gives reactant and product of iron oxidation reactions. In the Precambrian paleosol illustrated (Figure 4), these molar ratios indicate that the profile was oxidized and well drained, but little leached, calcified or salinized. 

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