Texas, elements

Finite Element Study of the Anomalous Behaviour of Remote Field Eddy Currents Proc. 7th Int. Conf on Offshore Mechanics, Houston, Texas 1988... 

Evaporite Basin Sulfur Deposits. Elemental sulfur occurs in another type of subsurface deposit similar to the salt-dome stmctures in that the sulfur is associated with anhydrite or gypsum. The deposits are sedimentary, however, and occur in huge evaporite basins. It is befleved that the sulfur in these deposits, like that in the Gulf Coast salt domes, was derived by hydrocarbon reduction of the sulfate material and assisted by anaerobic bacteria. The sulfur deposits in Italy (Sicily), Poland, Iraq, the CIS, and the United States (western Texas) are included in this category. 

Neither of these processes has been commercialized, although some aspects of the methodology were incorporated into a plant operated for a short time by the Elcor Company (31). This company, which operated briefly in western Texas in 1968 using natural gypsum, is the only one known to have commercially attempted to recover elemental sulfur from this material by a two-step thermal process. The Elcor plant was shut down shortly after it began operation. Although most technical problems were said to have been solved, production costs were prohibitive. 

Compiled from Daubert, T. E., R. R Danner, H. M. Sibiil, and C. C. Stebbins, DIPPR Data Compilation of Pure Compound Properties, Project 801 Sponsor Release, July, 1993, Design Institute for Physical Property Data, AlChE, New York, NY and from Thermodynamics Research Center, Selected Values of Properties of Hydrocarbons and Related Compounds, Thermodynamics Research Center Hydrocarbon Project, Texas A M University, College Station, Texas (extant 1994). The compounds are considered to be formed from the elements in their standard states at 298.15 K and 101,325 P. These include C (graphite) and S (rhombic). Enthalpy of combustion is the net value for the compound in its standard state at 298.15K and 101,325 Pa. 

Helium, the second element in the periodic table, has atomic number 2. This means its nucleus contains two protons and has a 2+ charge. The neutral atom, then, contains two electrons. There are two stable isotopes, helium-4 and helium-3, but the helium found in nature is almost pure helium-4. Helium is found in certain natural gas fields and is separated as a by-product. Sources of helium are rare and most of the world supply is produced in the United States, mainly in Texas and Kansas. 

We have developed another bench for the measurement of the contrast value. Contrast measurement have been carried out on the MMA fabricated by Texas Instrument, in order to establish the test procedure (Zamkotsian et al., 2002a Zamkotsian et al., 2003). We can address several parameters in our experiment, as the size of the source, its location with respect to the micro-elements, the wavelength, and the input and output pupil size. In order to measure the contrast, the micro-mirrors are tilted between the ON position (towards the spectrograph) or the OFF position (towards a light trap). Contrast exceeding 400 has been measured for a 10° ON/OFF angle. Effects of object position on the micro-mirrors and contrast reduction when the exit pupil size is increasing have also been revealed. 

White DH, King KA, Mitchell CA, et al. 1986. Trace elements in sediments, water, and American coots (Fulica americans) at a coal-fired power plant in Texas, 1979-1982. Bull Environ Contam Toxicol 36 376-383. 

Hinkley T.K., Lamother P.J., Meeker G.P., Jiang X., Miller M.E., Fulton R. Trace elements deposited with dusts in Southwestern U.S. - enrichments, fluxes, comparison with records from elsewhere. Proceedings of the ICAR5/GCTE-SEN Joint Conference, International Center for Arid and Semiarid Lands Studies 2002 Lubbock, Texas Texas Tech University, 2002. 

Robert A. Brown is Warren K. Lewis Professor of Chemical Engineering and Provost at the Massachusetts Institute of Technology. He received his B.S. (1973) and M.S. (1975) from the University of Texas, Austin, and his Ph.D. from the University of Minnesota in 1979. His research area is chemical engineering with specialization in fluid mechanics and transport phenomena, crystal growth from the melt, microdefect formation in semiconductors and viscoelastic fluids, bifurcation theory applied to transitions in flow problems, and finite element methods for nonlinear transport problems. He is a member of the National Academy of Engineering, the National Academy of Sciences, and the American Academy of Arts and Sciences. 

Custer, T.W. and C. A Mitchell. 1993. Trace elements and organochlorines in the shoalgrass community of the Lower Laguna Madre, Texas. Environ. Monitor. Assess. 25 235-246. 

Mora, M.A. 1996. Qrganochlorines and trace elements in four colonial waterbird species nesting in the lower Laguna Madre, Texas. Arch. Environ. Contam. Toxicol. 31 533-537. 

The analysis of tetramethylammonium hydroxide (TMAH) solutions manufactured by SACHEM Inc. of Cleburne, Texas, includes the determination of trace elements. These elements cause less-than-optimum performance of integrated circuit boards manufactured by SACHEM s customers that use these solutions in their processes. Alkali and alkaline earth metals (e.g., Li, Na, K, Mg, Ca, and Ba) can reduce the oxide breakdown voltage of the devices. In addition, transition and heavy metal elements (e.g., Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Au, and Pb) can produce higher dark current. Doping elements (e.g., B, Al, Si, P, As, and Sn) can alter the operating characteristics of the devices. In SACHEM s quality control laboratory, ICP coupled to mass spectrometry is used to simultaneously analyze multiple trace elements in one sample in just 1 to 4 min. This ICP-MS instrument is a state-of-the-art instrument that can provide high throughput and low detection Emits at the parts per thousand level. Trace elemental determination at the parts per thousand level must be performed in a clean room so that trace elemental contamination from airborne particles can be minimized. 

Brown and coworkers (17-18,47) reported compositions of dusts from cotton compresses and warehouses. Samples were removed with the aid of a sonic bath in hexane. The compresses were in Mississippi, Southeastern and Western Texas, and New Mexico. The samples in the bale press area were high in ash content with silicon the most abundant element (up to 18.7% in one New Mexico compress Scimple). Compared with card room dusts, samples from compresses were high in aluminum, silicon, chlorine, iron and magnesium and relatively low in potassium, phosphorus and zinc. The ratio of silica to silicon was high also for these scunples compared with textile mill dusts. 

Crade oil is a complex mixture that is between 50 and 95% hydrocarbon by weight. Table 1.5 shows the average elemental composition of crade oil. The oil industry classifies crade by its production location (e g., West Texas Intermediate, wn or Brent ), relative density (API gravity), viscosity ( light, intermediate, or heavy ), and sulfur content ( sweet for low sulfur, and soui for high sulfur). Additional classification is due to conventional and non-conventional oil as shown in Table 1.6. 

Sulfur has been known since ancient times primarily because it is a rather common substance. It is the 15th most common element in the universe, and though it is not found in all regions of the Earth, there are signiflcant deposits in south Texas and Louisiana, as well in all volcanoes. Sulfur makes up about 1% of the Earth s crust. 

Wiersema JM, Wright L, Rogers B, et al. 1984. Human exposure to potentially toxic elements through ambient air in Texas. In Proceedings of the 77th Meeting of the Air Pollution Control Association, San Francisco, CA, June 24-29, 1984. 

Researchers are looking at ways to reduce the amount of platinum yet retain the catalytic activity. Peter Strasser, a researcher at the University of Houston in Texas, and his colleagues are trying to develop a platinum alloy that will do the job. An alloy such as bronze is a combination of elements, which in the case of bronze are tin and copper. Engineers often use alloys because they offer properties that are superior to those of a single metal, as described in chapter 1. A platinum alloy that acts as an effective catalyst in fuel cell electrodes yet contains less platinum would save a substantial amount of money. 

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