Contamination effects

At high metals levels, the coking characteristics of a cracking catalyst can be greatly increased that is, the ratio of contaminant coke to catalytic coke can be quite high. The effect of the contaminant metals on the coke response is affected not only by the level of metals but also by the type of catalyst and the use of a metals passivator. Catalysts, which contain effective metals traps to inhibit the contaminant effects, do produce much less contaminant coke than catalyst without metal traps. 

In addition to cleanliness (contamination effects), surface morpholt and the alteration of composition during specimen preparation can cause serious artifacts in microanalysis. In some older instruments, the microscope itself produces undesirable high-energy X rays that excite the entire specimen, making difficult the accurate quantitation of locally changing composition. Artifacts also are observed in the EDS X-ray spectrum itself (see the article on EDS). 

Contaminants Concentration in the zones, cross-contamination effects... 

The current level of understanding of how aggregates form and break is not up to par with droplet breakup and coalescence. The reasons for this discrepancy are many Aggregates involve multibody interactions shapes may be irregular, potential forces that are imperfectly understood and quite susceptible to contamination effects. 

Initiation of long-term environmental monitoring studies in terrestrial and aquatic ecosystems to establish appropriate baseline concentrations and to separate these from contaminant effects (Kum-plainen and Koivistoninen 1977 WHO 1980 Hall and Pinkney 1985 Thompson et al. 1985). 

Johnson, L.L., D. Misitano, S.Y. Sol, G.M. Nelson, B. French, G.M. Ylitalo, and T. Horn. 1998. Contaminant effects on ovarian development and spawning success in rock sole from Puget Sound, Washington. Trans. Amer. Fish. Soc. 127 375-392. 

Finkelstein, M., et al., Immune function of cryopreserved avian peripheral white blood cells potential biomarkers of contaminant effects in wild birds, Arch. Environ. Contam. Toxicol., 44, 502, 2003. 

Ray ER. Contaminant Effects in Solid Oxide Fuel Cells. In HubnerWJ, editor. Proceedings of the Third Annual Fuel Cells Contractors Review Meeting, Washington, DC U.S. Department of Energy, 1992 document No. DOE/METC—91/6120 (DE91002085) 108-116. 

Containment building, for nuclear power facilities, 77 538 Containment landfills, 25 877 Contaminant coke, 77 705 Contaminant concentration, measurements of, 74 214 Contaminant deposition, from steam in turbines, 23 228-228 Contaminant effects, on magnesium and magnesium alloys, 75 370-373 Contaminant metals... 

N. Maskalick, "Contaminant Effects in Solid Oxide Fuel Cells," in Agenda and Abstracts, Joint Contractors Meeting, Fuel Cells and Coal-Fired Heat Engines Conference, U.S. DOE/METC, August 3-5, 1993. 

A. Pigeaud et al., "Trace Contaminant Effects and Emissions with Integrated Coal Gasification and Cleanup," 1994 Fuel Cell Seminar, Pgs. 539-542 (1994). 

Although the rate of mercury input to the ocean s surface waters has increased as a result of anthropogenic activities, it is not clear that the relatively high MMHg concentrations now seen in the larger fish, e.g., tuna, shark, and swordfish, are the result of pollution. Measurements of mercury levels in preserved fish collected over the past 100 years have proven inconclusive due to small sample sizes and contamination effects. 

Sometimes the risk of waste is estimated on the basis of nutrient cycling tests. As a rule such investigation is carried out for surface waste disposal or its land application. The carbon cycle is very sensitive to harmful compounds. Soil respiration is considered a useful indicator of the contaminants effects on soil microbial activity [56-59]. The production of carbon dioxide can be followed as short-term and long-term respiration tests. 

In this chapter, we later consider spin-polarized systems. One avenue of approach is to apply the spin unrestricted formalism, where SOs have different spatial orbitals for different spins. However, this procedure can introduce important spin contamination effects through the last term of Eq. (27) since the overlap matrix (5. These effects can be avoided by the use of spin-restricted theory. In this case only a single set of orbitals is used for a and / spins. 

Limited information exists on contaminant effects on barrier performance. 

They firmly selected the low sulfur route and embarked in heavy investments for hot metal desulfurization equipment and later in steel desulfurization ( ). Until 1973, however, the sulfur levels achieved by hot metal desulfurization did not help the final sulfur content because of the contaminating effect of cooling scrap in the Basic Oxygen Furnace (BOF), except in Japan where... 

Temperature control has an additional advantage with respect to the problem of chamber contamination. After a smog chamber has been used, some hydrocarbons and nitrogen compounds may remain adsorbed on the chamber walls. These may desorb in subsequent runs and, in some cases (e.g., HCHO), act as free radical sources to accelerate the photooxidation processes. The ability to bake out smog chambers while pumping to low pressures is therefore useful in reducing chamber contamination effects. 

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