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Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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1

Impacts of Ethanol on Anaerobic Production of Tert-Butyl Alcohol (TBA) from Methyl Tert-Butyl Ether (MTBE) in Groundwater  

E-Print Network [OSTI]

Methyl Tert-Butyl Ether (MTBE) in Groundwater P.I. names,Methyl tert-butyl ether (MTBE) is a contaminant of concernsubsurface environments. MTBE appears to be degraded readily

Scow, K M; MacKay, Douglas

2008-01-01T23:59:59.000Z

2

active methyl tert-butyl: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by Fusarium solani CiteSeer Summary: Fusarium solani degraded methyl tert-butyl ether (MTBE) and other oxygenated compounds from gasoline including tert-butyl alcohol (TBA). The...

3

Treatment of Methyl tert-Butyl Ether Vapors in Biotrickling Filters. 2.  

E-Print Network [OSTI]

vapors of methyl tert-butyl ether (MTBE), a gasoline additive of great environmental concern MTBE treatment are discussed. Introduction The rapidly rising number of reports of groundwater con- taminated with the gasoline additive methyl tert-butyl ether (MTBE) has raised concerns about its

4

Environmental Microbiology (2001) 3(6), 407416 Methyl tert-butyl ether (MTBE) degradation by a  

E-Print Network [OSTI]

Environmental Microbiology (2001) 3(6), 407±416 Methyl tert-butyl ether (MTBE) degradation of California, Riverside, Riverside, CA 92521, USA. Summary The widespread use of methyl tert-butyl ether (MTBE is often proposed as the most promising alter- native after treatment. However, MTBE biodegradation appears

5

IDENTIFYING THE USAGE PATTERNS OF METHYL TERT-BUTYL ETHER (MTBE) AND OTHER OXYGENATES IN GASOLINE USING GASOLINE  

E-Print Network [OSTI]

IDENTIFYING THE USAGE PATTERNS OF METHYL TERT-BUTYL ETHER (MTBE) AND OTHER OXYGENATES IN GASOLINE USING GASOLINE SURVEYS By Michael J. Moran, Rick M. Clawges, and John S. Zogorski U.S. Geological Survey 1608 Mt. View Rapid City, SD 57702 Methyl tert-butyl ether (MTBE) is commonly added to gasoline

6

Oxidation of methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE) by ozone and combined ozone/hydrogen peroxide  

SciTech Connect (OSTI)

The aim of this work was to study the reaction of ozone and combined ozone/hydrogen peroxide on oxygenated additives such as methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE) in dilute aqueous solution using controlled experimental conditions. Experiments conducted in a semi-continuous reactor with MTBE and ETBE in combination (initial concentration: 2 mmol/L of each) showed that ETBE was better eliminated than MTBE with both ozone and combined O[sub 3]/H[sub 2]O[sub 2]. batch experiments led to the determination of the ratio of the kinetic constants for the reaction of OH[degree]-radical with MTBE and ETBE (k[sub OH[degree]/ETBE]/k[sub OH[degree]//MTBE] = 1.7). Tert-butyl formate and tert-butyl acetate were identified as the ozonation byproducts of MTBE an ETBE, respectively, while tert-butyl alcohol was found to be produced during the ozonation of both compounds. 10 refs., 10 figs., 1 tab.

Leitner, N.K.V.; Papailhou, A.L.; Croue, J.P.; Dore, M. (Univ. de Poitiers (France)); Peyrot, J. (British Petroleum, Harfleur (France))

1994-01-01T23:59:59.000Z

7

Multiple steady states during reactive distillation of methyl tert-butyl ether  

SciTech Connect (OSTI)

This paper presents results of computer simulations of the synthesis of methyl tert-butyl ether (MTBE) in a fixed-bed reactor and in a reactive distillation column. These calculations clearly showed the advantages of MTBE synthesis in a catalytic distillation tower. Furthermore, the computer simulations showed that multiple steady states may occur in the reactive distillation column during MTBE synthesis in a broad range of operating conditions. An analysis of some sensitivity studies is presented.

Nijhuis, S.A. (Univ. of Amsterdam (Netherlands). Chemical Engineering Dept.); Kerkhof, F.P.J.M.; Mak, A.N.S. (Comprimo Engineers and Contractors, Amsterdam (Netherlands))

1993-11-01T23:59:59.000Z

8

Measurement of methyl-tert-butyl-ether (MTBE) in raw drinking water  

SciTech Connect (OSTI)

In order to assess the pathways for human exposure to methyl-tert-butyl-ether (MTBE) and to understand the extent of MTBE contamination in watersheds, a purge and trap gas chromatographic mass spectrometric method to measure part-per-trillion (ppt) concentrations of MTBE in environmental waters was developed. A variety of California's raw drinking waters were analyzed. No detectable MTBE was found in deep groundwater (>1000 feet). However shallow groundwater ({approx}250 feet) contained MTBE concentrations of non-detect to 1300 ppt. MTBE concentrations measured in rivers and lakes ranged from non-detect to 3500 ppt. East (San Francisco) Bay area rain water contained approximately 80 ppt MTBE.

Davisson, M L; Koester, C J; Moran, J E

1999-10-14T23:59:59.000Z

9

Review of the environmental behavior and fate of methyl tert-butyl ether  

SciTech Connect (OSTI)

A review of pertinent equations and current research indicates that when gasoline oxygenated with methyl tert-butyl ether (MTBE) comes into contact with water, large amounts of MTBe can dissolve. At 25 C, the water solubility of MTBE is about 5,000 mg/L for a gasoline that is 10% MTBE by weight, whereas for a nonoxygenated gasoline, the total hydrocarbon solubility in water is typically about 120 mg/L. Methyl tert-butyl ether sorbs only weakly to subsurface solids; therefore, sorption does not substantially retard the transport of MTBE by ground water. In addition, MTBE generally resists biodegradation in ground water. The half-life of MTBE in the atmosphere can be as short as 3 d in a regional airshed. In the air, MTBE tends to partition into atmospheric water, including precipitation. However, the washing out of gas-phase MTBE by precipitation will not, by itself, greatly alter the gas-phase concentration of the compound in the air. The partitioning of MTBE to precipitation can nevertheless result in concentrations as high as 3 {micro}g/L or more in urban precipitation and can contribute to the presence of MTBE in surface and ground water.

Squillace, P.J.; Zogorski, J.S. [Geological Survey, Rapid City, SD (United States); Pankow, J.F. [Oregon Graduate Inst. of Science and Technology, Beaverton, OR (United States). Dept. of Environmental Science and Engineering; Korte, N.E. [Oak Ridge National Lab., TN (United States). Environmental Science Div.

1997-09-01T23:59:59.000Z

10

Why methyl tert-butyl ether production by reactive distillation may yield multiple solutions  

SciTech Connect (OSTI)

This paper presents an explanation of why methyl tert-butyl ether (MTBE) production by reactive distillation may yield multiple solutions. Widely different composition profiles and conversions may, as already reported by Krishna and others, results with identical column specifications, depending on the initial estimates provided. A hypothesis yielding a qualitative understanding of this phenomenon has been developed. The inert n-butene plays a key role in the proposed explanation: As the reaction mixture is diluted with n-butene, the activity coefficient of methanol increases substantially and the temperature decreases. This dilution has a profound effect on the equilibrium conversion, enabling MTBE to escape from the reactive zone without decomposition. When methanol is fed below or in the lower part of the reactive zone of the column, the ``lifting capacity`` of the minimum boiling point MTBE-methanol azeotrope will also be important.

Hauan, S.; Hertzberg, T.; Lien, K.M. [Univ. of Trondheim (Norway)

1995-03-01T23:59:59.000Z

11

Exposure to methyl tert-butyl ether and benzene among service station attendants and operators  

SciTech Connect (OSTI)

Concerns for atmospheric pollution from auto exhaust have led to the blending of {open_quotes}oxygenates{close_quotes} with motor fuels. The most common oxygenate, methyl tert-butyl ether (MTBE) is currently required within several metropolitan areas (Denver and Phoenix) in the range of 12% of the motor fuel. Amendments to the Clean Air Act may expand this requirement to as many as 44 other areas of the United States in the near future. In consideration of the magnitude of potential uncontrolled exposures from its extensive use and a related concern involving the potential influence of MTBE blending on exposures to other constituents of gasoline (particularly benzene), an evaluation of exposures among service station attendants and operators was undertaken at the request, and in cooperation with, the American Petroleum Institute during the latter part of 1990. For application of the survey results to a broad audience, three categories or types of service stations were identified with regard to MTBE use and exposure potential: (a) service stations that do not use MTBE or use it only as an octane enhancer, (b) service stations with seasonal requirements to use 12-15% MTBE (the Denver, Colorado, and Phoenix, Arizona, metropolitan areas), and (c) service stations equipped with stage II (active) vapor recovery systems (several coastal areas, most notably Southern California). 4 refs., 4 tabs.

Hartle, R. [National Inst. for Occupational Safety and Health, Cincinnati, OH (United States)

1993-12-01T23:59:59.000Z

12

Reaction calorimetry study of the liquid-phase synthesis of tert-butyl methyl ether  

SciTech Connect (OSTI)

The liquid-phase addition of methanol to isobutene to give tert-butyl methyl ether (MTBE) on the ion-exchange resin Lewatit K2631 has been studied in a calorimetric reactor. Heat capacity of MTBE and enthalpy of the MTBE synthesis reaction in the temperature range 312--333 K have been determined. MTBE heat capacity in the liquid phase has been found to obey the equation c[sub P] (J/mol[center dot]K) = 472.34 [minus] 2.468(T/K) + 0.005071(T/K)[sup 2]. At 298 K the standard molar reaction enthalpy is [Delta]H[degree] = [minus]33.8 kJ/mol. A method to estimate apparent activation energies from heat flow rate in a given reaction has been developed and proved to be valid for the MTBE synthesis. Using this method, an apparent activation energy of 91.1--95.2 kJ/mol is calculated. A [minus]3.8 kJ/mol value has been found for the adsorption enthalpy of methanol on the ion-exchange resin Lewatit K2631 by a combination of reaction calorimetry and thermogravimetry. This allows the calculation of an activation energy on the gel phase of the resin of 91 kJ/mol.

Sola, L.; Pericas, M.A.; Cunill, F.; Iborra, M. (Univ. de Barcelona (Spain). Dept. d'Enginyeria Quimica)

1994-11-01T23:59:59.000Z

13

LIDEM unit for the production of methyl tert-butyl ether from butanes  

SciTech Connect (OSTI)

One of the basic problems in the production of motor fuels is how to obtain high-octane unleaded gasolines that will meet today`s ecological requirements. The term {open_quotes}reformulated gasolines{close_quotes} has come into general use throughout the world to denote fuels with a certain chemical composition. These gasolines consist of preselected components; as shown by worldwide experience, they must include oxygen-containing compounds that are distinguished by high octane numbers and low reactivities. Standards in effect in the United States, Japan, and certain Western European countries require that automotive gasolines must contain at least 2-4% by weight of oxygen-containing compounds (calculated as oxygen). In the last 15 years, in order to meet these requirements, production has been set up in various countries for the manufacture of high-octane oxygen-containing components known as oxygenates. The most common of these is methyl tert-butyl ether (MTBE), obtained by etherification of isobutene by methanol. Process technology developed by this last organization was used as the basis for constructing a unit in the Nizhnekamskneftekhim Production Association and at the Mazheikyai Petroleum Refinery in Lithuania. MTBE production has been held back mainly by a shortage of isobutene, which is obtained mainly from butane-butene cuts produced in cat crackers. In order to alleviate this shortage, it has been proposed that MTBE should be obtained from saturated C{sub 4} hydrocarbons that are recovered in processing oilfield associated gas, and also in the refinery from primary distillation units, catalytic reformers, and hydrocrackers. A working design was developed in 1991-1992 by Lengiproneftekhim for a basically new combination unit designed for the processing of saturated C{sub 4} hydrocarbons, which has been termed the LIDEM unit (Leningrad - isomerization - dehydrogenation - MTBE).

Rudin, M.G.; Zadvornov, M.A.

1994-09-01T23:59:59.000Z

14

Biodegradation of methyl tert-butyl ether by a bacterial pure culture  

SciTech Connect (OSTI)

A bacterial strain, PM1, which is able to utilize methyl tert-butyl ether (MTBE) as its sole carbon and energy source, was isolated from a mixed microbial consortium in a compost biofilter capable of degrading MTBE. Initial linear rates of MTBE degradation by 2 x 10{sup 6} cells ml{sup {minus}1} were 0.07, 1.17, and 3.56 {mu}g ml{sup {minus}1} h{sup {minus}1} for initial concentrations of 5, 50, and 500 {mu}g MTBE ml{sup {minus}1}, respectively. When incubated with 20 {mu}g of uniformly labeled [{sup 14}C]MTBE ml{sup {minus}1}, strain PM1 converted 46% to {sup 14}CO{sub 2} and 19% to {sup 14}C-labeled cells within 120 h. This yield is consistent with the measurement of protein accumulation at different MTBE concentrations from which was estimated a biomass yield of 0.18 of cells mg MTBE{sup {minus}1}. Strain PM1 was inoculated into sediment core material collected from a contaminated groundwater plume at Port Hueneme, California, in which there was no evidence of MTBE degradation. Strain PM1 readily degraded 20 {micro}g of MTBE ml{sup {minus}1} added to the core material. The rate of MTBE removal increased with additional inputs of 20 {micro}g of MTBE ml{sup {minus}1}. These results suggest that PM1 has potential for use in the remediation of MTBE-contaminated environments.

Hanson, J.R.; Ackerman, C.E.; Scow, K.M.

1999-11-01T23:59:59.000Z

15

Methyl tert-butyl ether (MTBE) is a volatile organic com-pound (VOC) derived from natural gas that is added to gas-  

E-Print Network [OSTI]

Methyl tert-butyl ether (MTBE) is a volatile organic com- pound (VOC) derived from natural gas Water in Urban and Agricultural Areas made from methanol, which is derived primarily from natural gas that is added to gas- oline either seasonally or year round in many parts of the United States to increase

16

alkyl tert-butyl ether: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by Fusarium solani CiteSeer Summary: Fusarium solani degraded methyl tert-butyl ether (MTBE) and other oxygenated compounds from gasoline including tert-butyl alcohol (TBA). The...

17

Kinetics and modeling of mixture effects during complete catalytic oxidation of benzene and methyl tert-butyl ether  

SciTech Connect (OSTI)

The performance of a catalytic incinerator depends on the nature of the compounds being oxidized and cannot be predicted simply by knowing the performance of the incinerator with pure-component model compounds. Considering the importance of mixture effects, an attempt was made to develop a combined model to predict the conversion when benzene and methyl tert-butyl ether (MTBE) are simultaneously oxidized. Complete catalytic oxidation of benzene and MTBE, singly and in mixtures, was investigated over a platinum catalyst. No inhibition effects were seen with benzene, but MTBE conversion was distinctly inhibited by benzene. A Mars-van Krevelen rate model was used to explain the results. Model parameters were obtained from pure-component experiments and then incorporated into a multicomponent model without any adjustment or additional rate parameters. The multicomponent model was able to predict the conversion of benzene and MTBE oxidation in the binary mixture using the pure-component data without adjustable parameters.

Dangi, S.; Abraham, M.A. [Univ. of Tulsa, OK (United States). Dept. of Chemical Engineering] [Univ. of Tulsa, OK (United States). Dept. of Chemical Engineering

1997-06-01T23:59:59.000Z

18

Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. [801Methyl tert-butyl ether  

SciTech Connect (OSTI)

The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. (2) Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. (3) Addition of methanol to slurry phase FT synthesis making iso-olefins. During the sixth quarter we completed the construction of the slurry bubble column reactor (SBCR), conducted initial shake-down experiments in a cold-flow mode, and finalized the selection process of the acid catalysts for conversion of syngas-produced alcohols and isobutylene to MTBE (scheme 2). Tasks 3, 4, and 5 are awaiting complete implementation of the SBCR system.

Marcelin, G.

1992-06-24T23:59:59.000Z

19

Treatment of Methyl tert-Butyl Ether Contaminated Water Using a Dense  

E-Print Network [OSTI]

-butyl ether (MTBE) in a dense medium plasma (DMP) reactor utilizing gas chromatog- raphy-massspectrometryandgaschromatography-thermal conductivity techniques. A rate law is developed for the removal of MTBE from an aqueous solution in the DMP. The oxidation products from the treatment of MTBE-contaminated water in the DMP reactor were found

Dandy, David

20

Kinetics and mechanism of the sonolytic destruction of methyl tert-butyl ether by ultrasonic irradiation in the presence of ozone  

SciTech Connect (OSTI)

The kinetics and mechanism of the sonolytic degradation of methyl tert-butyl ether (MTBE) have been investigated at an ultrasonic frequency of 205 kHz and power of 200 W L{sup {minus}1}. The observed first-order degradation rate constant for the loss of MTBE increased from 4.1 {times} 10{sup {minus}4} s{sup {minus}1} to 8.5 {times} 10{sup {minus}4} s{sup {minus}1} as the concentration of MTBE decreased from 1.0 to 0.01 mM. In the presence of O{sub 3}, the sonolytic rate of destruction of MTBE was accelerated substantially. The rate of MTBE sonolysis with ozone was enhanced by a factor of 1.5--3.9 depending on the initial concentration of MTBE. tert-Butyl formate, tert-butyl alcohol, methyl acetate, and acetone were found to be the primary intermediates and byproducts of the degradation reaction with yields of 8, 5, 3, and 12%, respectively. A reaction mechanism involving three parallel pathways that include the direct pyrolytic decomposition of MTBE, the direct reaction of MTBE with ozone, and the reaction of MTBE with hydroxyl radical is proposed.

Kang, J.W. [Yonsei Univ., Wonju (Korea, Republic of). Dept. of Industrial Environment and Health] [Yonsei Univ., Wonju (Korea, Republic of). Dept. of Industrial Environment and Health; Hoffmann, M.R. [California Inst. of Tech., Pasadena, CA (United States). W.M. Keck Labs.] [California Inst. of Tech., Pasadena, CA (United States). W.M. Keck Labs.

1998-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Whole-genorne analysis of the methyl tert-butyl ether-degrading beta-proteobacterium Methylibium petroleiphilum PM1  

SciTech Connect (OSTI)

Methylibium petroleiphilum PM1 is a methylotroph distinguished by its ability to completely metabolize the fuel oxygenate methyl tert-butyl ether (MTBE). Strain PM1 also degrades aromatic (benzene, toluene, and xylene) and straight-chain (C, to C,,) hydrocarbons present in petroleum products. Whole-genome analysis of PM1 revealed an similar to 4-Mb circular chromosome and an similar to 600-kb megaplasmid, containing 3,831 and 646 genes, respectively. Aromatic hydrocarbon and alkane degradation, metal resistance, and methylotrophy are encoded on the chromosome. The megaplasmid contains an unusual t-RNA island, numerous insertion sequences, and large repeated elements, including a 40-kb region also present on the chromosome and a 29-kb tandem repeat encoding phosphonate transport and cobalamin biosynthesis. The megaplasmid also codes for alkane degradation and was shown to play an essential role in MTBE degradation through plasmid-curing experiments. Discrepancies between the insertion sequence element distribution patterns, the distributions of best BLASTP hits among major phylogenetic groups, and the G+C contents of the chromosome (69.2%) and plasmid (66%), together with comparative genome hybridization experiments, suggest that the plasmid was recently acquired and apparently carries the genetic information responsible for PM1's ability to degrade MTBE. Comparative genomic hybridization analysis with two PM1-like MTBE-degrading environmental isolates (similar to 99% identical 16S rRNA gene sequences) showed that the plasmid was highly conserved (ca. 99% identical), whereas the chromosomes were too diverse to conduct resequencing analysis. PM1's genome sequence provides a foundation for investigating MTBE biodegradation and exploring the genetic regulation of multiple biodegradation pathways in M. petroleiphilum and other MTBE-degrading beta-proteobacteria.

Kane, Staci R. [Lawrence Livermore National Laboratory (LLNL); Chakicherla, Anu Y. [Lawrence Livermore National Laboratory (LLNL); Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Schmidt, Radomir [University of California, Davis; Shin, M [U.S. Department of Energy, Joint Genome Institute; Legler, Tina C. [Lawrence Livermore National Laboratory (LLNL); Scow, Kate M. [University of California, Davis; Larimer, Frank W [ORNL; Lucas, Susan [Joint Genome Institute, Walnut Creek, California; Richardson, P M [U.S. Department of Energy, Joint Genome Institute; Hristova, Krassimira R. [University of California, Davis

2007-03-01T23:59:59.000Z

22

Exposure to methyl tert-butyl ether, benzene, and total hydrocarbons at the Singapore-Malaysia causeway immigration checkpoint  

SciTech Connect (OSTI)

The primary aim of this study was to determine the extent and levels of exposure to volatile organic compounds (VOCs) from automobile emissions in a group of immigration officers at a busy cross-border checkpoint. A majority (80%) of the workers monitored were exposed to benzene at levels between 0.01 and 0.5 ppm, with only 1.2% exceeding the current Occupational Safety and Health Administration occupational exposure limit of 1 ppm. The geometric mean (GM) concentrations of 8-hr time-weighted average exposure were 0.03 ppm, 0.9 ppm, and 2.46 ppm for methyl-tert-butyl ether (MTBE), benzene, and total hydrocarbons (THC), respectively. The highest time-weighted average concentrations measured were 1.05 ppm for MTBE, 2.01 ppm for benzene, and 34 ppm for THC. It was found that motorbikes emitted a more significant amount of pollutants compared with motor cars. On average, officers at the motorcycle booths were exposed to four to five times higher levels of VOCs (GMs of 0.07 ppm, 0.23 ppm, and 4.7 ppm for MTBE, benzene, and THC) than their counterparts at the motor car booths (GMs of 0.01 ppm, 0.05 ppm, and 1.5 ppm). The airborne concentrations of all three pollutants correlated with the flow of vehicle traffic. Close correlations were also noted for the concentrations in ambient air for the three pollutants measured. Benzene and MTBE had a correlation coefficient of 0.97. The overall findings showed that the concentrations of various VOCs were closely related to the traffic density, suggesting that they were from a common source, such as exhaust emissions from the vehicles. The results also indicated that although benzene, MTBE, and THC are known to be volatile, a significant amount could still be detected in the ambient environment, thus contributing to our exposure to these compounds. 4 refs., 6 figs.

Tan, C.; Ong, H.Y.; Kok, P.W. [and others

1996-12-31T23:59:59.000Z

23

Control Study of Ethyl tert-Butyl Ether Reactive Distillation Muhammad A. Al-Arfaj  

E-Print Network [OSTI]

-butyl ether (ETBE) for gasoline blending as a replacement for methyl tert-butyl ether (MTBE) because and be blended with ETBE in the gasoline pool. Even for neat operation, if the conversion is low, the unconverted

Al-Arfaj, Muhammad A.

24

Manipulation of the HIF–Vegf pathway rescues methyl tert-butyl ether (MTBE)-induced vascular lesions  

SciTech Connect (OSTI)

Methyl tert-butyl ether (MTBE) has been shown to be specifically anti-angiogenic in piscine and mammalian model systems at concentrations that appear non-toxic in other organ systems. The mechanism by which MTBE targets developing vascular structures is unknown. A global transcriptome analysis of zebrafish embryos developmentally exposed to 0.00625–5 mM MTBE suggested that hypoxia inducible factor (HIF)-regulated pathways were affected. HIF-driven angiogenesis via vascular endothelial growth factor (vegf) is essential to the developing vasculature of an embryo. Three rescue studies were designed to rescue MTBE-induced vascular lesions: pooled blood in the common cardinal vein (CCV), cranial hemorrhages (CH), and abnormal intersegmental vessels (ISV), and test the hypothesis that MTBE toxicity was HIF–Vegf dependent. First, zebrafish vegf-a over-expression via plasmid injection, resulted in significantly fewer CH and ISV lesions, 46 and 35% respectively, in embryos exposed to 10 mM MTBE. Then HIF degradation was inhibited in two ways. Chemical rescue by N-oxaloylglycine significantly reduced CCV and CH lesions by 30 and 32% in 10 mM exposed embryos, and ISV lesions were reduced 24% in 5 mM exposed zebrafish. Finally, a morpholino designed to knock-down ubiquitin associated von Hippel–Lindau protein, significantly reduced CCV lesions by 35% in 10 mM exposed embryos. In addition, expression of some angiogenesis related genes altered by MTBE exposure were rescued. These studies demonstrated that MTBE vascular toxicity is mediated by a down regulation of HIF–Vegf driven angiogenesis. The selective toxicity of MTBE toward developing vasculature makes it a potentially useful chemical in the designing of new drugs or in elucidating roles for specific angiogenic proteins in future studies of vascular development. - Highlights: • Global gene expression of MTBE exposed zebrafish suggested altered HIF1 signaling. • Over expression of zebrafish vegf-a rescues MTBE-induced vascular lesions. • Inhibiting PHD or knocking down VHL rescues MTBE-induced vascular lesions. • HIF1-Vegf driven angiogenesis is a target for MTBE vascular toxicity.

Bonventre, Josephine A., E-mail: josephine.bonventre@oregonstate.edu [Rutgers, The State University of New Jersey, Joint Graduate Program in Toxicology, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Rutgers, The State University of New Jersey, Department of Biochemistry and Microbiology, 76 Lipman Dr., New Brunswick, NJ 08901 (United States); Oregon State University, Department of Environmental and Molecular Toxicology, 1011 Agricultural and Life Sciences Bldg, Corvallis, OR 97331 (United States); Kung, Tiffany S., E-mail: tiffany.kung@rutgers.edu [Rutgers, The State University of New Jersey, Joint Graduate Program in Toxicology, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Rutgers, The State University of New Jersey, Department of Biochemistry and Microbiology, 76 Lipman Dr., New Brunswick, NJ 08901 (United States); White, Lori A., E-mail: lawhite@aesop.rutgers.edu [Rutgers, The State University of New Jersey, Joint Graduate Program in Toxicology, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Rutgers, The State University of New Jersey, Department of Biochemistry and Microbiology, 76 Lipman Dr., New Brunswick, NJ 08901 (United States); Cooper, Keith R., E-mail: cooper@aesop.rutgers.edu [Rutgers, The State University of New Jersey, Joint Graduate Program in Toxicology, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Rutgers, The State University of New Jersey, Department of Biochemistry and Microbiology, 76 Lipman Dr., New Brunswick, NJ 08901 (United States)

2013-12-15T23:59:59.000Z

25

Determination of Methyl tert-Butyl Ether and tert-Butyl Alcohol in Water by Solid-Phase Microextraction/Head Space Analysis in Comparison to EPA Method 5030/8260B  

SciTech Connect (OSTI)

Methyl tert-butyl ether (MTBE) is now one of the most common groundwater contaminants in the United States. Groundwater contaminated with MTBE is also likely to be contaminated with tert-butyl alcohol (TBA), because TBA is a component of commercial grade MTBE, TBA can also be used as a fuel oxygenate, and TBA is a biodegradation product of MTBE. In California, MTBE is subject to reporting at concentrations greater than 3 {micro}g/L. TBA is classified as a ''contaminant of current interest'' and has a drinking water action level of 12 {micro}g/L. In this paper, we describe the development and optimization of a simple, automated solid phase microextraction (SPME) method for the analysis of MTBE and TBA in water and demonstrate the applicability of this method for monitoring MTBE and TBA contamination in groundwater, drinking water, and surface water. In this method, the headspace (HS) of a water sample is extracted with a carboxen/polydimethylsiloxane SPME fiber, the MTBE and TBA are desorbed into a gas chromatograph (GC), and detected using mass spectrometry (MS). The method is optimized for the routine analysis of MTBE and TBA with a level of quantitation of 0.3 {micro}g/L and 4 {micro}g/L, respectively, in water. MTBE quantitation was linear for over two orders of concentration (0.3 {micro}g/L -80 {micro}g/L). TBA was found to be linear within the range of 4 {micro}g/L-7,900 {micro}g/L. The lower level of detection for MTBE is 0.03 {micro}g/L using this method. This SPME method using headspace extraction was found to be advantageous over SPME methods requiring immersion of the fiber into the water samples, because it prolonged the life of the fiber by up to 400 sample analyses. This is the first time headspace extraction SPME has been shown to be applicable to the measurement of both MTBE and TBA at concentrations below regulatory action levels. This method was compared with the certified EPA Method 5030/8260B (purge-and-trap/GC/MS) using split samples from laboratory bioreactors treating MTBE contaminated water and applied to environmental samples collected throughout the East Bay area of California. Results from the SPME-HS/GC/MS method were directly comparable to the EPA Method 5030/8260B. This method provides an simple, inexpensive, accurate, and sensitive alternative to EPA Method 5030/8260B for the analysis of MTBE and TBA in water samples.

Oh, Keun-Chan; Stringfellow, William T.

2003-10-02T23:59:59.000Z

26

Treatment of methyl tert-butyl ether vapors in a biotrickling filters. 2. Analysis of the rate-limiting step and behavior under transient conditions  

SciTech Connect (OSTI)

Detailed experiments were performed with gas phase biotrickling filters treating vapors of methyl tert-butyl ether (MTBE), a gasoline additive of great environmental concern. A particular emphasis was placed on the analysis of the rate-limiting step, and it was found that the process was mostly limited by the biological reaction rather than by mass transfer. Further experiments involved the study of the dynamic behavior of the biotrickling filters under simulated field conditions. In all cases, the biotrickling filters adapted rapidly to the new conditions, and new steady states were obtained within hours. The relevance of the results and the implications as far as implementation of biotrickling filters for field MTBE treatment are discussed.

Fortin, N.Y.; Deshusses, M.A. [Univ. of California, Riverside, CA (United States). Dept. of Chemical and Environmental Engineering] [Univ. of California, Riverside, CA (United States). Dept. of Chemical and Environmental Engineering

1999-09-01T23:59:59.000Z

27

Cytotoxic and DNA-damaging effects of methyl tert-butyl ether and its metabolites on HL-60 cells in vitro  

SciTech Connect (OSTI)

Methyl tert-butyl ether (MTBE) is a widely used oxygenate in unleaded gasoline; however, few studies have been conducted on the toxicity of this compound. This study evaluates the cytotoxic and DNA-damaging effects of MTBE and its metabolites in a human haemopoietic cell line, HL-60. The metabolites of MTBE studied include tertiary butyl alcohol (TBA), {alpha}-hydroxyisobutyric acid (HIBA), and formaldehyde. Comet assay is used to assess DNA damage, and the cytotoxicity is investigated by lactate dehydrogenease (LDH) release. The results show no significant cytotoxic effects of MTBE, TBA, and HIBA over a concentration ranging from 1 to 30 mM. Formaldehyde, in contrast, causes a substantial LDH release at a concentration of 5 {mu}M. Hydrogen peroxide, a known oxidative agent, at concentrations ranging from 10 to 100 {mu}M, produces a significant dose-related increase in DNA damage, whereas a much higher concentration of MTBE (1 to 30 mM) is required to produce a similar observation. The genotoxic effects of TBA and HIBA appear to be identical to that of MTBE. Conversely, DNA damage is observed for formaldehyde at a relatively low concentration range (5 to 100 {mu}M). These findings suggest that MTBE and its metabolites, except formaldehyde, have relatively low cytotoxic and genotoxic effects. 16 refs., 4 figs.

Tang, G.H. [Xian Medical Univ. (China); Shen, Y.; Shen, H.M. [National Univ. of Singapore (Singapore)] [and others

1996-12-31T23:59:59.000Z

28

Treatment of methyl tert-butyl ether vapors in biotrickling filters. 1. Reactor startup, steady-state performance, and culture characteristics  

SciTech Connect (OSTI)

An aerobic microbial consortium able to biodegrade methyl tert-butyl ether (MTBE) was enriched in two waste air biotrickling filters after continuous operation for 6 months. After this acclimation phase, the two laboratory-scale biotrickling filters were able to degrade up to 50 g of MTBE per cubic meter of reactor per hour, a value comparable to other gasoline constituents. Such high performance could be sustained for at least 4--6 weeks. After the acclimation phase, the MTBE degrading biotrickling filters were characterized by their almost full conversion of MTBE to carbon dioxide and the absence of any degradation byproducts in either the gas or the liquid phase. They also exhibited a very high specific degradation activity per amount of biomass, and a low rate of biomass accumulation. An observed biomass yield of 0.1 g g{sup {minus}1} and a specific growth rate of 0.025 day{sup {minus}1} were determined for the biotrickling filter process culture. Further data on MTBE mass transfer and on the dynamic behavior of the biotrickling filter are presented in part 2 of this paper. Overall, the results demonstrate that MTBE can be effectively biodegraded under carefully controlled environmental conditions.

Fortin, N.Y.; Deshusses, M.A. [Univ. of California, Riverside, CA (United States). Dept. of Chemical and Environmental Engineering] [Univ. of California, Riverside, CA (United States). Dept. of Chemical and Environmental Engineering

1999-09-01T23:59:59.000Z

29

Production of methyl tert-alkyl ethers  

SciTech Connect (OSTI)

The transition to the use of unleaded gasolines has required the replacement of tetraethyl lead by oxygen-containing compounds such as methanol, ethanol, and ethers, which are termed {open_quotes}oxygenates{close_quotes} in the technical literature. These may be used in commercial gasolines in amounts of 10-15% by volume, equivalent to 2% oxygen by weight. When methyl tert-butyl ether (MTBE) is used, the oxygen content may amount to 2.7% by weight. This oxygenate gives a significant improvement of knock resistance of naphtha fractions, the greatest effects being observed for straight-run naphthas and reformer naphthas produced under normal conditions; the MTBE also improves the engine power and economy characteristics and lowers the carbon monoxide content in the exhaust by 15-30% and the hydrocarbon content by 7-8%. This paper describes methods for the production of MTBE and also methyl tert-alkyl ethers.

Trofimov, V.A.

1995-01-01T23:59:59.000Z

30

Effect of Ethanol and Methyl-tert-Butyl Ether on Monoaromatic Hydrocarbon Biodegradation: Response Variability for Different Aquifer Materials Under Various Electron-Accepting Conditions  

SciTech Connect (OSTI)

Aquifer microcosms were used to determine how ethanol and methyl-tert-butyl ether (MtBE) affect monoaromatic hydrocarbon degradation under different electron-accepting conditions commonly found in contaminated sites experiencing natural attenuation. Response variability was investigated by using aquifer material from four sites with different exposure history. The lag phase prior to BTEX (benzene, toluene, ethylbenzene, and xylenes) and ethanol degradation was typically shorter in microcosms with previously contaminated aquifer material, although previous exposure did not always result in high degradation activity. Toluene was degraded in all aquifer materials and generally under a broader range of electron-accepting conditions compared to benzene, which was degraded only under aerobic conditions. MtBE was not degraded within 100 days under any condition, and it did not affect BTEX or ethanol degradation patterns. Ethanol was often degraded before BTEX compounds, and had a variable effect on BTEX degradation as a function of electron-accepting conditions and aquifer material source. An occasional enhancement of toluene degradation by ethanol occurred in denitrifying microcosms with unlimited nitrate; this may be attributable to the fortuitous growth of toluene-degrading bacteria during ethanol degradation. Nevertheless, experiments with flow-through aquifer columns showed that this beneficial effect could be eclipsed by an ethanol-driven depletion of electron acceptors, which significantly inhibited BTEX degradation and is probably the most important mechanism by which ethanol could hinder BTEX natural attenuation. A decrease in natural attenuation could increase the likelihood that BTEX compounds reach a receptor as well as the potential duration of exposure.

Ruiz-Aguilar, G L; Fernandez-Sanchez, J M; Kane, S R; Kim, D; Alvarez, P J

2003-10-06T23:59:59.000Z

31

alkyl-tert alkyl ethers: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

TREAT METHYL- TERT-BUTYL ETHER CONTAMINATED CiteSeer Summary: Methyl-tert-butyl ether (MTBE) is a commonly used gasoline additive. Leaking underground storage tank systems,...

32

Sonolytic destruction of methyl tert-butyl ether by ultrasonic irradiation: The role of O{sub 3}, H{sub 2}O{sub 2}, frequency, and power density  

SciTech Connect (OSTI)

The kinetics of degradation of methyl tert-butyl ether (MTBE) by ultrasonic irradiation in the presence of ozone as functions of applied frequencies and applied power are investigated. Experiments are performed over the frequency range of 205--1,078 kHz. The higher overall reaction rates are observed at 358 and 618 kHz and then at 205 and 1,078 kHz. The observed pseudo-first-order rate constant, k{sub 0}, for MTBE degradation increases with increasing power density up to 250 W L{sup {minus}1}. A linear dependence of the first-order rate constant, k{sub O{sub 3}}, for the simultaneous degradation of O{sub 3} on power density is also observed. Naturally occurring organic matter (NOM) is shown to have a negligible effect on observed reaction rates.

Kang, J.W.; Hung, H.M.; Lin, A.; Hoffmann, M.R. [California Inst. of Tech., Pasadena, CA (United States). W.M. Keck Labs.] [California Inst. of Tech., Pasadena, CA (United States). W.M. Keck Labs.

1999-09-15T23:59:59.000Z

33

Aerobic mineralization of MTBE and tert-butyl alcohol by stream-bed sediment microorganisms  

SciTech Connect (OSTI)

Microorganisms indigenous to the stream-bed sediments at two gasoline-contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-{sup 14}C]-MTBE and 84% of [U-{sup 14}C]-TBA were degraded to {sup 14}CO{sub 2} under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.

Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H. [Geological Survey, Columbia, SC (United States)] [Geological Survey, Columbia, SC (United States)

1999-06-01T23:59:59.000Z

34

{gamma}-aminobutyric acid{sub A} (GABA{sub A}) receptor regulates ERK1/2 phosphorylation in rat hippocampus in high doses of Methyl Tert-Butyl Ether (MTBE)-induced impairment of spatial memory  

SciTech Connect (OSTI)

Experimental and occupational exposure to Methyl Tert-Butyl Ether (MTBE) has been reported to induce neurotoxicological and neurobehavioral effects, such as headache, nausea, dizziness, and disorientation, etc. However, the molecular mechanisms involved in MTBE-induced neurotoxicity are still not well understood. In the present study, we investigated the effects of MTBE on spatial memory and the expression and function of GABA{sub A} receptor in the hippocampus. Our results demonstrated that intraventricular injection of MTBE impaired the performance of the rats in a Morris water maze task, and significantly increased the expression of GABA{sub A} receptor {alpha}1 subunit in the hippocampus. The phosphorylation of ERK1/2 decreased after the MTBE injection. Furthermore, the decreased ability of learning and the reduction of phosphorylated ERK1/2 level of the MTBE-treated rats was partly reversed by bicuculline injected 30 min before the training. These results suggested that MTBE exposure could result in impaired spatial memory. GABA{sub A} receptor may play an important role in the MTBE-induced impairment of learning and memory by regulating the phosphorylation of ERK in the hippocampus.

Zheng Gang; Zhang Wenbin [Department of Occupational and Environmental Health, School of Public Health and Military Preventive Medicine, Fourth Military Medical University, Xi'an 710032 (China); Zhang Yun [465 Hospital, Jilin Medical College, Jilin 132001 (China); Chen Yaoming; Liu Mingchao; Yao Ting; Yang Yanxia; Zhao Fang [Department of Occupational and Environmental Health, School of Public Health and Military Preventive Medicine, Fourth Military Medical University, Xi'an 710032 (China); Li Jingxia; Huang Chuanshu [Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987 (United States); Luo Wenjing [Department of Occupational and Environmental Health, School of Public Health and Military Preventive Medicine, Fourth Military Medical University, Xi'an 710032 (China)], E-mail: luowenj@fmmu.edu.cn; Chen Jingyuan [Department of Occupational and Environmental Health, School of Public Health and Military Preventive Medicine, Fourth Military Medical University, Xi'an 710032 (China)], E-mail: jy_chen@fmmu.edu.cn

2009-04-15T23:59:59.000Z

35

he increasing frequency of detection of the widely used gasoline additive methyl tert-  

E-Print Network [OSTI]

T he increasing frequency of detection of the widely used gasoline additive methyl tert- butyl, the September 15, 1999, Report of the Blue Ribbon Panel on Oxygenates in Gasoline (1) states that between 5 with large releases (e.g., LUFTs). Unprecedented growth in use Use of MTBE as a gasoline additive began

36

Experimental Pathology Laboratories, Inc. Methyl-Tertiary-Butyl Ether  

E-Print Network [OSTI]

COORDINATOR'S REPORT FOR LIFETIME CARCINOGENICITY STUDY OF METHYL-TERTIARY-BUTYL ETHER (MTBE) IN SPRAGUE CARCINOGENICITY STUDY OF METHYL-TERTIARY-BUTYL ETHER (MTBE) IN SPRAGUE-DAWLEY RATS CONDUCTED AT THE CANCER

Baker, Chris I.

37

antioxidant butylated hydroxytoluene: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by Fusarium solani CiteSeer Summary: Fusarium solani degraded methyl tert-butyl ether (MTBE) and other oxygenated compounds from gasoline including tert-butyl alcohol (TBA). The...

38

Determination of methyl tert. butyl ether (MTBE) in gasoline  

SciTech Connect (OSTI)

A GLC-acid extraction method is described for the determination of MTBE in gasolines. The method consists of a programmed GLC analysis starting at about room temperature conducted before and after extraction with cold 85% phosphoric acid. This treatment results in the preferential solubility of ethers and other oxygenated compounds while minimizing the reaction of olefins and aromatics which may be present in the gasolines. Plotting various known concentrations of MTBE in gasolines against the concentrations determined in the same samples by the authors methodology results in a straight line relationship. The concentration of MTBE in any sample of gasoline may thus be determined using their GLC-extraction procedure and the calibration line. The analysis can accommodate a wide choice of standard GLC columns and programs. 2 refs., 1 fig., 1 tab.

Feldman, J.; Orchin, M. (Univ. of Cincinnati, OH (United States))

1993-02-01T23:59:59.000Z

39

Atmospheric Methyl Tertiary Butyl Ether (MTBE) at a Rural Mountain Site in California  

E-Print Network [OSTI]

Atmospheric Methyl Tertiary Butyl Ether (MTBE) at a Rural Mountain Site in California Gunnar W. Schade,* Gabrielle B. Dreyfus, and Allen H. Goldstein ABSTRACT (CARB) measured MTBE in urban regions in 1995­ 1996, reporting a range of 0.4 to 13.2 ppbv in the LosMethyl tertiary butyl ether (MTBE

Cohen, Ronald C.

40

Radical-anions of aromatic compounds. VII. Reaction of the products from the reduction of nitrobenzene by sodium with isopropyl and tert-butyl iodides  

SciTech Connect (OSTI)

The reaction of the products from the reduction of nitrobenzene by one and two equivalents of sodium with isopropyl iodide leads to the formation of N,O-diisopropylphenylhydroxylamine, while the reaction with tert-butyl iodide leads to p-(tert-butyl)nitrobenzene. Such a change in the nature of the reaction product in the transition from the primary and secondary alkyl halides to the tertiary alkyl halides clearly results from a change in the S/sub N/2 mechanism to the S/sub RN/1 mechanism, involving transfer of an electron from the radical-anion or dianion of nitrobenzene to the alkyl halide. The formation of considerable amounts of azoxybenzene in the reaction with tert-butyl iodide shows that the dianion and, to a lesser degree, the radical-anion of nitrobenzene exhibit basic characteristics.

Danilova, N.K.; Shteingarts, V.D.

1986-09-20T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

State Restrictions on Methyl Tertiary Butyl Ether (released in AEO2006)  

Reports and Publications (EIA)

By the end of 2005, 25 states had barred, or passed laws banning, any more than trace levels of methyl tertiary butyl ether (MTBE) in their gasoline supplies, and legislation to ban MTBE was pending in 4 others. Some state laws address only MTBE; others also address ethers such as ethyl tertiary butyl ether (ETBE) and tertiary amyl methyl ether (TAME). Annual Energy Outlook 2006 assumes that all state MTBE bans prohibit the use of all ethers for gasoline blending.

2006-01-01T23:59:59.000Z

42

Photoionization of methyl t-butyl ether (MTBE) and t-octyl methyl ether (TOME) and analysis of their pyrolyses by  

E-Print Network [OSTI]

Photoionization of methyl t-butyl ether (MTBE) and t-octyl methyl ether (TOME) and analysis 1999; accepted 20 July 1999 Abstract The pyrolysis products of neutral methyl-d3 t-butyl ether (MTBE-d3 from thermal cracking patterns. MTBE and TOME both exhibit base peaks at m/z 73 (which shifts to m/z 76

Morton, Thomas Hellman

43

E-Print Network 3.0 - anhydride-vinyl methyl ether Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

4-Methyl-2-pentanol Other secondary alcohols... - quire handling with precautions. Acrolein tert-Butyl methyl ether Di(1-propynl) ether n... Methoxy-1,3,5,7- cyclooctatetraene...

44

Treatment of Methyl tert-Butyl Ether Vapors in Biotrickling Filters. 1.  

E-Print Network [OSTI]

because of its low cost and blending characteristics. Depending on the season, reformulated gasoline of reactor per hour, a value comparable to other gasoline constituents. Such high performance could enhancer in gasoline. The use of MTBE increased rapidly after the 1990 Clean Air Act Amendments required

45

Impacts of Ethanol on Anaerobic Production of Tert-Butyl Alcohol (TBA) from Methyl Tert-Butyl Ether (MTBE) in Groundwater  

E-Print Network [OSTI]

Project title: Impacts of Ethanol on Anaerobic Production oftert-butanol (TBA). As ethanol is being promoted as ainvestigate the effect of ethanol release on existing MTBE

Scow, K M; MacKay, Douglas

2008-01-01T23:59:59.000Z

46

Supporting Information A scalable synthesis of the (S)-4-(tert-butyl)-2-(pyridin-2-yl)-4,5-dihydrooxazole  

E-Print Network [OSTI]

with a three-pitched curved blade, an internal thermometer, and a reflux condenser equipped with a two a steam of N2. The flask was charged with (S)-tert-leucine (15.08 g, 115.0 mmol, 1.00 equv, 99% ee and replaced by a condenser and the reaction was heat to reflux (80 °C oil bath). After 20 h the reaction

Stoltz, Brian M.

47

Treatment of methyl t-butyl ether contaminated water using a dense medium plasma reactor, a mechanistic and kinetic investigation  

E-Print Network [OSTI]

and oxidation mechanisms of methyl t-butyl ether (MTBE) in a dense medium plasma (DMP) reactor utilizing gas for the removal of MTBE from an aqueous solution in the DMP reactor. Rate constants are also derived for three reactor configurations and two pin array spin rates. The oxidation products from the treatment of MTBE

Dandy, David

48

Fluctuating micro-heterogeneity in water–tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies  

SciTech Connect (OSTI)

Water–tert-butyl alcohol (TBA) binary mixture exhibits a large number of thermodynamic and dynamic anomalies. These anomalies are observed at surprisingly low TBA mole fraction, with x{sub TBA} ? 0.03–0.07. We demonstrate here that the origin of the anomalies lies in the local structural changes that occur due to self-aggregation of TBA molecules. We observe a percolation transition of the TBA molecules at x{sub TBA} ? 0.05. We note that “islands” of TBA clusters form even below this mole fraction, while a large spanning cluster emerges above that mole fraction. At this percolation threshold, we observe a lambda-type divergence in the fluctuation of the size of the largest TBA cluster, reminiscent of a critical point. Alongside, the structure of water is also perturbed, albeit weakly, by the aggregation of TBA molecules. There is a monotonic decrease in the tetrahedral order parameter of water, while the dipole moment correlation shows a weak nonlinearity. Interestingly, water molecules themselves exhibit a reverse percolation transition at higher TBA concentration, x{sub TBA} ? 0.45, where large spanning water clusters now break-up into small clusters. This is accompanied by significant divergence of the fluctuations in the size of largest water cluster. This second transition gives rise to another set of anomalies around. Both the percolation transitions can be regarded as manifestations of Janus effect at small molecular level.

Banerjee, Saikat; Furtado, Jonathan; Bagchi, Biman, E-mail: bbagchi@sscu.iisc.ernet.in [SSCU, Indian Institute of Science, Bangalore 560012 (India)] [SSCU, Indian Institute of Science, Bangalore 560012 (India)

2014-05-21T23:59:59.000Z

49

Low-temperature CVD of iron, cobalt, and nickel nitride thin films from bis[di(tert-butyl)amido]metal(II) precursors and ammonia  

SciTech Connect (OSTI)

Thin films of late transition metal nitrides (where the metal is iron, cobalt, or nickel) are grown by low-pressure metalorganic chemical vapor deposition from bis[di(tert-butyl)amido]metal(II) precursors and ammonia. These metal nitrides are known to have useful mechanical and magnetic properties, but there are few thin film growth techniques to produce them based on a single precursor family. The authors report the deposition of metal nitride thin films below 300?°C from three recently synthesized M[N(t-Bu){sub 2}]{sub 2} precursors, where M?=?Fe, Co, and Ni, with growth onset as low as room temperature. Metal-rich phases are obtained with constant nitrogen content from growth onset to 200?°C over a range of feedstock partial pressures. Carbon contamination in the films is minimal for iron and cobalt nitride, but similar to the nitrogen concentration for nickel nitride. X-ray photoelectron spectroscopy indicates that the incorporated nitrogen is present as metal nitride, even for films grown at the reaction onset temperature. Deposition rates of up to 18?nm/min are observed. The film morphologies, growth rates, and compositions are consistent with a gas-phase transamination reaction that produces precursor species with high sticking coefficients and low surface mobilities.

Cloud, Andrew N.; Abelson, John R., E-mail: abelson@illinois.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 201 Materials Science and Engineering Building, 1304 W. Green St., Urbana, Illinois 61801 (United States); Davis, Luke M.; Girolami, Gregory S., E-mail: girolami@scs.illinois.edu [School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801 (United States)

2014-03-15T23:59:59.000Z

50

Fluctuating micro-heterogeneity in water - tert-butyl alcohol mixtures and lambda-type divergence of the mean cluster size with phase transition-like multiple anomalies  

E-Print Network [OSTI]

Water - tert-butyl alcohol (TBA) binary mixture exhibits a large number of thermodynamic and dynamic anomalies. These anomalies are observed at surprisingly low TBA mole fraction, with $x_{\\text{TBA}} \\approx 0.03 - 0.07$. We demonstrate here that the origin of the anomalies lies in the local structural changes that occur due to self-aggregation of TBA molecules. We observe a percolation transition of the TBA molecules at $x_{\\text{TBA}} \\approx 0.05$. We note that "islands" of TBA clusters form even below this mole fraction, while a large spanning cluster emerges above that mole fraction. At this percolation threshold, we observe a lambda-type divergence in the fluctuation of the size of the largest TBA cluster, reminiscent of a critical point. Alongside, the structure of water is also perturbed, albeit weakly, by the aggregation of TBA molecules. There is a monotonic decrease in the tetrahedral order parameter of water, while the dipole moment correlation shows a weak non-linearity. Interestingly, water molecules themselves exhibit a reverse percolation transition at higher TBA concentration, $x_{\\text{TBA}} \\approx 0.45$, where large spanning water clusters now break-up into small clusters. This is accompanied by significant divergence of the fluctuations in the size of largest water cluster. This second transition gives rise to another set of anomalies around. Both the percolation transitions can be regarded as manifestations of Janus effect at small molecular level.

Saikat Banerjee; Jonathan Furtado; Biman Bagchi

2014-02-20T23:59:59.000Z

51

Toxicity of methyl tertiary butyl ether to Daphnia magna and photobacterium phosphoreum  

SciTech Connect (OSTI)

Methyl tertiary butyl ether (MTBE) is a liquid organic compound added to gasoline to increase its oxygen content and to reduce the emission of carbon monoxide during combustion in many urban areas. In order to meet the 1990 Clean Air Act amendments, gasoline must contain 2.7% oxygen (by weight) or 15% (by volume) of MTBE in gasoline to meet the regulations for the control of carbon monoxide emissions. Health effects caused by inhalation of MTBE include headaches, dizziness, irritated eyes and nausea; MTBE is one of cancer--causing chemicals. Intracaval injection of MTBE (0.2 mg/kg) caused the highest mortality (100%) in rats. General anesthetic effect induced by MTBE was found at or above 1200 mg/kg body weight; Rosenkranz and Klopman (1991) predicted that MTBE is neither a genotoxicant nor a carcinogen. Nevertheless, the safety of using MTBE in oxygenated fuels is now being questioned from its potential as groundwater pollutant. This study measures the toxicity of MTBE to Daphnia magna and Photobacterium phosphoreum. 13 refs.

Gupta, G.; Lin, Y.J. [Univ. of Maryland Eastern Shore, Princess Anne, MD (United States)

1995-10-01T23:59:59.000Z

52

Disposition, metabolism, and toxicity of methyl tertiary butyl ether, an oxygenate for reformulated gasoline  

SciTech Connect (OSTI)

Studies of the toxicology of methyl tertiary butyl ether (MTBE) were reviewed as a possible information base for evaluating the health effects of evaporative emissions from reformulated gasoline (RFG). Perirenal fat/blood MTBE concentration ratios ranged from 9.7 to 11.6 after 15 wk of intermittent exposure. During an oxyfuels program in Fairbanks, AK, blood levels of occupationally exposed workers were 0.2-31.5 {mu}g/L MTBE and 1.6 to 72.2 {mu}g/L TBA with a mean TBA:MTBE blood concentration ratio of 4.2. In patients who received MTBE by percutaneous, transhepatic puncture for the dissolution of cholesterol gallstones, concentrations of MTBE in fat tissue reached 60 and 300 {mu}g/g at a treatment time when mean blood MTBE was less than 20 {mu}g/ml. The results of laboratory and clinical studies indicate that metabolites of MTBE may contribute to the nephropathy, neoplasms, and other pathological changes associated with repeated exposure to MTBE in experimental animals. It is concluded that such studies can provide a well-defined database for quantitatitive safety comparisons and health risk-benefit analyses of MTBE and other oxygenates in RFG. 39 refs., 1 tab.

Hutcheon, D.E.; Hove, W. ten; Boyle, J. III [UMDNJ, New Jersey Medical Schook, Newark, NJ (United States)] [UMDNJ, New Jersey Medical Schook, Newark, NJ (United States); Arnold, J.D. [Arnold & Arnold, Inc., Kansas City, MO (United States)] [Arnold & Arnold, Inc., Kansas City, MO (United States)

1996-04-05T23:59:59.000Z

53

Observation on the biodegradation and bioremediation potential of methyl t-butyl ether  

SciTech Connect (OSTI)

There have been few reports documenting evidence for the biodegradation of the fuel oxygenate alkyl ether, methyl t-butyl ether (MTBE) in groundwater, soils, and biosludges. Partial (or complete) microbial breakdown of MTBE has been observed in an anaerobic subsoil, a river sediment under methanogenic conditions, a cyclohexane-degrading bacterial consortium and a pure culture of the methylotroph, Methylisnus trichosporium OB3b. An aerobic bacterial enrichment (BC-1) isolated from an industrial transient (non-accumulating) metabolic intermediate. The studies suggest that MTBE is cleaved by BC-1 to TBA which is then metabolized via isopropanol and acetone. There is little information on the occurrence of indigenous MTBE-degraders in groundwater, soils and activated sludges. Preliminary evidence has been obtained, however, from a marketing terminal groundwater site that naturally-occurring MTBE-degraders are present in some monitoring wells. Microcosm experiments with groundwater from this aquifer show that MTBE is aerobically degraded (no TBA formed) with a first-order decay rate (0.31/day) similar to BTEX. Also, MTBE did not inhibit the intrinsic biodegradation potential of BTEX in groundwater microcosms. In summary, the data presented indicate that MTBE biodegradation has been observed in some environmental media. Further work is needed to assess the feasibility of using indigenous or derived aerobic and anaerobic MTBE-degrading cultures for treating fuel ethers in groundwaters or wastewater with in-situ or ex-situ bioremediation technologies.

Salanitro, J.; Wisniewski, H.; McAllister, P. [Shell Development Co., Houston, TX (United States)

1995-12-31T23:59:59.000Z

54

Acute toxicity of methyl-tertiary-butyl ether (MTBE) to aquatic organisms  

SciTech Connect (OSTI)

Due to the recent amendment of the Clean Air Act, oxygenates are now being added to gasolines to boost octane and reduce air pollution from combustion in heavily populated areas. Oxygenates such as alcohols (i.e. methanol) and ethers (methyl-tertiary-butyl ether, MTBE) are commonly being used. A series of bioassay studies have been conducted with MTBE, one of the most commonly used octane-enhancing additives. Freshwater and marine studies were conducted with fish, invertebrates and algae to determine the impact of this material on the environment following accidental spills. Static-renewal studies were run to ensure maintenance of MTBE, a highly volatile material in the test containers. Chemical confirmation of exposure concentrations demonstrated the adequacy of the exposure system. Mysid shrimp were highly sensitive to MTBE, with significantly less effect observed with the other species evaluated. These data have implications for spill response, particularly since MTBE is slow to biodegrade and will rapidly move through groundwater. Comparative data for other oxygenates will also be discussed.

BenKinney, M.T.; Barbieri, J.F.; Gross, J.S.; Naro, P.A. [Stonybrook Labs. Inc., Princeton, NJ (United States)

1994-12-31T23:59:59.000Z

55

An evaluation of the 3M Organic Vapor Monitor #3500 as a short term exposure limit sampling device for acetone, methyl ethyl ketone, and methyl iso butyl ketone  

E-Print Network [OSTI]

. An exploded view of the monitor is illustrated in Figure 1. The theory of diffusive sampling considers a concentration gra- dient between the ambient air and the adsorbent to be the driving force for sampling. For the adsorption to be controlled by diffu...AN EVALUATION OF THE 3M ORGANIC VAPOR MONITOR 43500 AS A SHOR'I TERM EXPOSURE LIMIT SAMPLING DEVICE FOR ACETONE, METHYL ETHYL KETONE, AND METHYL ISO BUTYL KETONE A Thesis by LLOYD B. ANDREW III Submitted to the Graduate College of Texas ASM...

Andrew, Lloyd B.

2012-06-07T23:59:59.000Z

56

Whole-Genome Analysis of Methyl tert-Butyl Ether-Degrading Beta-Proteobacterium Methylibium petroleiphilum PM1  

E-Print Network [OSTI]

D. J. Slomczynski. 2003. BTEX/MTBE bioremediation: BionetsScow, and L. Alvarez-Cohen. MTBE and benzene biodegradationinteractions in BTEX and MTBE mixtures by an MTBE-degrading

2007-01-01T23:59:59.000Z

57

Kinetics and mechanism of the thermal dissociation of O,O'-bis(1,3,5-TRI-tert-butyl-4-oxo-2,5-cyclo-hexadienyl)-p-benzoquinone dioxime in solution  

SciTech Connect (OSTI)

The kinetics and mechanism of the thermal dissociation of O,O'-bis(1,3,5-tri-tert-butyl-4-oxo-2,5-cyclohexadienyl)-p-benzoquinone dioxime (quinol ether) in solutions in nonpolar solvents were investigated. The dissociation of the quinol ether is reversible two-stage process and involves the formation of an intermediate radical. In relation to the reaction conditions (initial concentration, temperature) the dissociation rate of the quinol ether obeys the kinetic equations omega = k/sub eff/ x c/sup 1/2/ or omega = k/sub 1/c. The change in the reaction order is due to the ratio of the rates of dissociation of the intermediate radical and of its reaction with the phenoxyl radical. The ESR spectra were recorded on a Varian E-9 radiospectrometer with high-frequency modulation of 100 kHz.

Khizhnyi, V.A.; Danilova, T.A.; Goloverda, G.Z.; Dobronravova, Z.A.

1987-09-20T23:59:59.000Z

58

Alveolar breath sampling and analysis to assess exposures to methyl tertiary butyl ether (MTBE) during motor vehicle refueling  

SciTech Connect (OSTI)

In this study we present a sampling and analytical methodology that can be used to assess consumers` exposures to methyl tertiary butyl ether (MTBE) that may result from routine vehicle refueling operations. The method is based on the collection of alveolar breath samples using evacuated one-liter stainless steel canisters and analysis using a gas chromatograph-mass spectrometer equipped with a patented `valveless` cryogenic preconcentrator. To demonstrate the utility of this approach, a series of breath samples was collected from two individuals (the person pumping the fuel and a nearby observer) immediately before and for 64 min after a vehicle was refueled with premium grade gasoline. Results demonstrate low levels of MTBE in both subjects` breaths before refueling, and levels that increased by a factor of 35 to 100 after the exposure. Breath elimination models fitted to the post exposure measurements indicate that the half-life of MTBE in the first physiological compartment was between 1.3 and 2.9 min. Analysis of the resulting models suggests that breath elimination of MTBE during the 64 min monitoring period was approximately 155 {mu}g for the refueling subject while it was only 30 {mu}g for the nearby observer. This analysis also shows that the post exposure breath elimination of other gasoline constituents was consistent with previously published observations. 20 refs., 3 figs., 4 tabs.

Lindstrom, A.B.; Pleil, J.D. [U.S. Environmental Protection Agency, Research Triangle Park, NC (United States)

1996-07-01T23:59:59.000Z

59

Fourier transform electron paramagnetic resonance study of the photoreduction of anthraquinone with 4-methyl-2,6-di-tert-butylphenol in alcoholic solutions  

SciTech Connect (OSTI)

Using FT-EPR following laser excitation, the primary photochemical process in the photoreduction of anthraquinone with 4-methyl-2,6-di-tert-butylphenol was investigated. High-resolved spin-polarized EPR spectra taken with nanosecond time resolution gave unambiguous evidence for a two-step hydrogen abstraction reaction, consisting of a primary electron transfer followed by proton abstraction with a time delay, which allows for a noticeable escape probability of the initially generated anthrasemiquinone radical anion (AQ{sup {sm_bullet}minus}). The time dependence of the EPR intensities of the neutral 10-hydroxy-anthroxyl radical (AQH{sup {sm_bullet}}) as well as of AQ{sup {sm_bullet}} could be simulated for the full experimentally accessible time interval of 10 ns to 100 {mu}s. The kinetic model used invokes optical spin polarization, spin-lattice relaxation, radical generation, and AQH{sup {sm_bullet}}AQ interconversion. In addition, from an analysis of the highly-resolved FT-EPR spectra a complete set of AQH{sup {sm_bullet}} hyperfine splitting (hfs) constants could be measured in two different alcohols for the first time. 30 refs., 4 figs., 2 tabs.

Plueschau, M.; Kroll, G. [Universitaet Dortmund (Germany); Dinse, K.P. [TH Darmstadt (Germany)] [and others

1992-10-29T23:59:59.000Z

60

Thermally Switchable Thin Films of an ABC Triblock Copolymer of Poly(n-butyl methacrylate)-poly(methyl methacrylate)-poly(2-fluoroethyl methacrylate)  

SciTech Connect (OSTI)

The thermo-responsive behavior of polymer films consisting of novel linear triblock copolymers of poly(n-butyl methacrylate)-poly(methyl methacrylate)-poly(2-fluoroethyl methacrylate) (PnBuMA-PMMA-P2FEMA) are reported using differential scanning calorimetry (DSC), atomic forcing microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contacting angle (CA) measurements. The surface morphology, wettability and chemical structure of thin films of these triblock copolymers on silicon wafers as a function of temperature have been investigated. It has been shown that the wettability of the films is thermally switchable. Detailed structural analysis shows that thermo-responsive surface composition changes are produced. The underlying mechanism of the thermoresponsive behavior is discussed.

Zhang, Shanju [Georgia Institute of Technology; Liu, Zhan [Georgia Institute of Technology; Bucknall, David G. [Georgia Institute of Technology; He, Lihong [ORNL; Hong, Kunlun [ORNL; Mays, Jimmy [ORNL; Allen, Mark [Georgia Institute of Technology

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

RELATIONS BETWEEN THE DETECTION OF METHYL TERT-BUTYL ETHER (MTBE) IN SURFACE AND GROUND WATER AND ITS CONTENT IN GASOLINE  

E-Print Network [OSTI]

AND ITS CONTENT IN GASOLINE By Michael J. Moran, Mike J. Halde, Rick M. Clawges and John S. Zogorski U in the United States as an octane enhancer and oxygenate in gasoline. Octane enhancement began in the late 1970's with the phase-out of tetraethyl lead from gasoline. The use of oxygenates was expanded

62

he U.S. Geological Survey's (USGS) National Water-Quality Assess-  

E-Print Network [OSTI]

of the wells included methyl tert-butyl ether (MTBE), tetrachloroethene (PCE), dichlorodifluoromethane, 1

63

Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2  

E-Print Network [OSTI]

K. : Atmospheric chemistry of gasoline-related emissions:chemistry. Methyl tert-butyl ether is a solvent and gasoline

2010-01-01T23:59:59.000Z

64

Comparison of SPME headspace analysis to U.S. EPA method5030/8260B for MTBE monitoring  

SciTech Connect (OSTI)

A novel method for analysis of methyl tert-butyl ether andtert-butyl alcohol using solid phase microextraction is described andcompared to a standard method.

Stringfellow, William T.; Oh, Kuen-Chan

2005-02-01T23:59:59.000Z

65

Pyrolysis of Organic Molecules Relevant to Combustion as Monitored by Photoionization Time-of-Flight Mass Spectrometry  

E-Print Network [OSTI]

is observed, which is similar to MTBE in this system whichisobutene formed from MTBE, is found to occur. REFERENCES [methyl tert-butyl ether (MTBE) and tert-amyl methyl ether (

Weber, Kevin Howard

2010-01-01T23:59:59.000Z

66

Life-cycle Environmental Inventory of Passenger Transportation in the United States  

E-Print Network [OSTI]

Methyl tert?Butyl Ether (MTBE); http://www.atsdr.cdc.gov/Methyl Tertiary Butyl  Ether  (MTBE),  which  was  easily accounting was not performed on MTBE and the result  of 

Chester, Mikhail V

2008-01-01T23:59:59.000Z

67

Water Quality  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

which can lead to public health problems. * MtBE (Methyl tert Butyl Ether), a gasoline additive, has begun to contaminate ground water supplies. * Similarly, perchlorate has...

68

Stratospheric ozone, global warming, and the principle of unintended consequences - an ongoing science and policy story  

E-Print Network [OSTI]

as methyl-tert-butyl ether (MTBE), lubricating oil and itsthe environment. Use of the MTBE additive in gasoline wasof gasoline laced with MTBE into groundwater resulted in

2013-01-01T23:59:59.000Z

69

Effects of water chemistry on NF/RO membrane structure and performance  

E-Print Network [OSTI]

methyl tert-butyl ether (MTBE), benzene, ethylbenzene,TCE** Industrial C 2 HCl 3 MTBE** [48] Industrial C 5 H 12 O

Mo, Yibing

2013-01-01T23:59:59.000Z

70

Cometabolic bioremediation  

E-Print Network [OSTI]

Intrinsic bioremediation of MTBE-contaminated groundwater atcontaminants, e.g. PCE, TCE, MTBE, TNT, dioxane, atrazine,Methyl tert-butyl ether (MTBE) has also been remediated

Hazen, Terry C.

2010-01-01T23:59:59.000Z

71

Oxidative desulfurization of dibenzothiophene with tert-butyl hydro peroxide in a photochemical micro-reactor.  

E-Print Network [OSTI]

??Sulfur content in fuels is an increasingly critical environmental issue. Hydrodesulfurization removes sulfur from hydrocarbons; however, further desulfurization is necessary in fuels. New methods are… (more)

Hebert, Eilleen M.

2007-01-01T23:59:59.000Z

72

Thermal and Photochemistry of tert-Butyl Iodide on Rutile TiO(110). | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2 andThe1 MembersStability of MnBi

73

Equilibrium thermodynamic analysis of liquid-phase ethyl tert-butylether (ETBE) synthesis  

SciTech Connect (OSTI)

Methyl tertiary butyl ether (MTBE) is now the second largest volume organic chemical, only behind ethylene, produced in the U.S. This is remarkable since its commercial production began barely two decades ago. Although MTBE is currently the industry standard, it has been proposed that ethanol and other renewable additives make up to 30% of the oxygenate market. As a result, ethyl tertiary butyl ether (ETBE, or 2-ethyoxy 2-methyl propane), derived from renewable ethanol and isobutylene, has emerged as a promising new oxygenate. ETBE also has a somewhat lower blending Reid vapor pressure as well as a higher octane number than MTBE. This paper describes the thermodynamic equilibrium constant for the production of ETBE.

Jensen, K.L.; Datta, R. [Univ. of Iowa, Iowa City, IA (United States)

1994-12-31T23:59:59.000Z

74

QUANTIFYING NON-POINT SOURCES OF VOLATILE ORGANIC COMPOUNDS IN STORMWATER FROM A PARKING LOT  

E-Print Network [OSTI]

-butyl ether (MTBE) on urban particles indicates a site- specific interaction between MTBE and a particulate is a possible source only for the gasoline oxygenate methyl tert-butyl ether (MTBE). Lopes and Bender (1998

75

Monitoring synaptic protein dynamics with higher temporal, spatial, and molecular resolution  

E-Print Network [OSTI]

Spectrometry mSOG MiniSOG MTBE Methyl tert-butyl ether mTORMethyl tert-butyl ether (MTBE, 1.4 mL) was then added for1,000 g, 5 min). The MTBE layer was collected into a 1.5-mL

Butko, Margaret

2012-01-01T23:59:59.000Z

76

International Journal of Mass Spectrometry 249250 (2006) 303310 Pyrolysis of 2-methoxy-2,3,3-trimethylbutane (MTMB) monitored by  

E-Print Network [OSTI]

used fuel oxygenates MTBE and TAME), the predominance of bond homolysis at temperatures >900 K suggests homologues ­ methyl tert-butyl ether (MTBE) and tert-amyl methyl ether (TAME) ­ present a new set of problems discussed as alternatives to MTBE and TAME, because they are expected to be much less soluble in water. More

Morton, Thomas Hellman

77

Measurements of volatile organic compounds at a suburban ground site (T1) in Mexico City during the MILAGRO 2006 campaign: measurement comparison, emission ratios, and source attribution  

E-Print Network [OSTI]

methyl tert-butyl ether (MTBE) at 57 amu has been previouslyby a fragment of MTBE (62%) with minor contributions fromFortner and Knighton, 2008). MTBE also in- terfered (16%)

2011-01-01T23:59:59.000Z

78

APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Aug. 2004, p. 47204726 Vol. 70, No. 8 0099-2240/04/$08.00 0 DOI: 10.1128/AEM.70.8.47204726.2004  

E-Print Network [OSTI]

contamination of surface and groundwater resources by the gasoline oxygenate methyl tert-butyl ether (MTBE) is leading to its phaseout. Ethanol, a likely candidate to substitute MTBE, is increasingly being used

Alvarez, Pedro J.

79

Assessing the Effectiveness of California's Underground Storage Tank Annual Inspection Rate Requirements  

E-Print Network [OSTI]

Methyl Tert-Butyl Ether (MTBE), a gasoline additive. Thefor the lion’s share of MTBE contamination, as well asIn response to the MTBE crisis, California increased the

Cutter, W. Bowman

2008-01-01T23:59:59.000Z

80

Trichloroethene Removal From Waste Gases in Anaerobic Biotrickling Filters Through Reductive Dechlorination  

E-Print Network [OSTI]

methyl tert-butyl ether (MTBE) vapors into water was used.MTBE is highly soluble in water (dimensionless Henry’sgas stream was laden with MTBE vapors (200-300 mg m -3 )

Popat, Sudeep Chandrakant

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

E-Print Network 3.0 - ammoniated glycyrrhizin butylated Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ammoniated glycyrrhizin butylated Search Powered by Explorit Topic List Advanced Search Sample search results for: ammoniated glycyrrhizin butylated Page: << < 1 2 3 4 5 > >> 1...

82

Reverse Atom Transfer Radical Polymerization of Methyl Methacrylate in Room-Temperature Ionic Liquids  

E-Print Network [OSTI]

, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China Received 14, the removal and recycling of the catalytic materials become important. It is expected that using ionic liquids as ATRP media. They performed the copper(I)-mediated ATRP of methyl methacrylate (MMA) in 1-butyl-3

Wan, Xin-hua

83

Water Research 37 (2003) 37563766 Seasonal and daily variations in concentrations of methyl-  

E-Print Network [OSTI]

by volume to gasoline from November to February, and blending 11% MTBE by volume during the rest of the year; accepted 24 March 2003 Abstract Methyl-tertiary-butyl ether (MTBE), an additive used to oxygenate gasoline of gasoline-powered watercraft. This paper documents and explains both seasonal and daily variations in MTBE

Toran, Laura

84

Physico-chemical and biological characterization of an aquifer polluted with Yves Benoit (1)  

E-Print Network [OSTI]

to in order to meet specific requirements. Oxygenates such as methyl tert-butyl ether (MTBE) or ethyl tert on groundwater was not estimated prior to their utilization and the actual level of MTBE and ETBE contamination of MTBE- and ETBE-biodegradation is quite poor. Two directives have been adopted in the EU to promote

Paris-Sud XI, Université de

85

Functionalization/passivation of porous graphitic carbon with di-tert-amylperoxide  

SciTech Connect (OSTI)

Porous graphitic carbon (PGC) particles were functionalized/passivated in situ in packed beds at elevated temperature with neat di-tert-amylperoxide (DTAP) in a column oven. The performance of these particles for high performance liquid chromatography (HPLC) was assayed before and after this chemistry with the following analytes: benzene, toluene, ethyl benzene, n-propyl benzene, n-butyl benzene, p-xylene, phenol, 4-methylphenol, phenetole, 3,5-xylenol, and anisole. After the first functionalization/passivation, the retention factors, k, of these compounds decreased by about 5% and the number of theoretical plates (N) increased by ca. 15%. These values of k then remained roughly constant after a second functionalization/ passivation but a further increase in N was noticed. In addition, after each of the reactions, the peak asymmetries decreased by ca. 15%, for a total of ca. 30%. The columns were then subjected twice to methanol at 100 C for 5 h at 1 mL/min. After these stability tests, the values of k remained roughly constant, the number of plates increased, which is favorable, and the asymmetries rose and then declined, where they remained below the initial values for the unfunctionalized columns. Functionalized and unfunctionalized particles were characterized by scanning electron microscopy and BET measurements, which showed no difference between the functionalized and unfunctionalized materials, and X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS), where ToF-SIMS suggested some chemical differences between the functionalized and unfunctionalized materials. In particular ToF-SIMS suggested that the expected five-carbon fragments from DTAP exist at higher concentrations on DTAP-functionalized PGC. First principle calculations on model graphitic surfaces suggest that the first addition of a DTAP radical to the surface proceeds in an approximately isothermal or slightly favorable fashion, but that subsequent DTAP additions are then increasingly thermodynamically favorable. Thus, this analysis suggests that the direct functionalization/passivation of PGC with DTAP is plausible. Chemometric analyses of the chromatographic and ToF-SIMS data are also presented.

Jensen, David S.; Gupta, Vipul; Olsen, Rebecca E.; Miller, Alex T.; Davis, Robert C.; Ess, Daniel; Zhu, Zihua; Vail, Michael A.; Dadson, Andrew; Linford, Matthew R.

2011-11-18T23:59:59.000Z

86

Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Chloride As the Acid  

E-Print Network [OSTI]

Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Supporting Information ABSTRACT: Routes to new tungsten alkylidene complexes that contain tert and tungsten, especially aryls that are mono- or disubstituted in the ortho position(s).2 However, it has

Müller, Peter

87

Biodegradation of methyl tertiary butyl ether (MTBE) using a granular activated carbon trickling filter  

SciTech Connect (OSTI)

A pilot scale trickling filter was constructed using granular activated carbon (GAC) as the packing medium and inoculated with a microbial culture known to degrade MTBE. The packing dimensions were 0.076 m in diameter and 0.22 m deep. The unit operated with recycling flow for two months before a biofilm was observed on the GAC. After two additional months the biofilm had visibly spread throughout the packing. A few pieces of GAC were placed in a sealed bottle with MTBE-contaminated water and nutrients. Headspace analysis performed over 14 days confirmed that MTBE degradation was occurring. The trickling filter was converted to continuous flow and operated for one month at a nominal flow rate of 0.1 L/min and a hydraulic loading rate of 32 m{sup 3}/m{sup 2}-d. Samples were collected for analysis at the spray nozzle and at the bottom of the trickling filter. Fractional removal varied with influent MTBE concentration, temperature and liquid flow rate. Percent MTBE removal was as high as 85%. A mechanical failure resulted in the trickling filter bed drying and percent removal dropping to less than 1 percent. However, the system recovered within five days.

Converse, B.M.; Schroeder, E.D.; Chang, D.P.Y.

1999-07-01T23:59:59.000Z

88

Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Chloride as the Acid  

E-Print Network [OSTI]

Routes to new tungsten alkylidene complexes that contain tert-butylimido or adamantylimido ligands have been devised that begin with a reaction between WCl[subscript 6] and 4 equivalents of HNR(TMS) to give [W(NR)[subscript ...

Jeong, Hyangsoo

89

Race to license new MTBE and TAME routes heats up  

SciTech Connect (OSTI)

With refineries and petrochemical manufacturers continuing to gear up production of oxygenates for use in reformulated fuels, new routes to methyl tert-butyl ether (MTBE) and tert-amyl methyl ether (TAME) are clearly hot items in the licensing market. And probably nowhere has the competition become as intense as in offerings for skeletal isomerization technologies to boost ethers production from fluid catalytic cracking and steam cracking.

Rotman, D.

1993-01-06T23:59:59.000Z

90

8180 Phys. Chem. Chem. Phys., 2011, 13, 81808185 This journal is c the Owner Societies 2011 Cite this: Phys. Chem. Chem. Phys., 2011, 13, 81808185  

E-Print Network [OSTI]

photofragment translational spectroscopy. The tert-butyl radical was produced from flash pyrolysis of azo

Neumark, Daniel M.

91

Shear viscosity measurements in the binary mixture butyl cellosolve-water near its upper and lower critical consolute points  

E-Print Network [OSTI]

has been measured for a two-component critical liquid system, butyl cellosolve-water, in the region to report measurements of the shear viscosity of critical binary mixture butyl cello- solve (2-n353 Shear viscosity measurements in the binary mixture butyl cellosolve-water near its upper

Boyer, Edmond

92

PROOF COPY [023113] 008209QEE [023113]008209QEE  

E-Print Network [OSTI]

as a replacement for the gasoline oxygenate, methyl tert-butyl ether MTBE , may lead to indirect impacts related facilitate the migration of pre-existing contamination. MTBE 25 mg/L influent was not degraded inlet by one order of magnitude relative to columns fed BTEX alone or with MTBE. However, 16S

Alvarez, Pedro J.

93

Environmental Toxicology and Chemistry, Vol. 21, No. 12, pp. 26312639, 2002 Printed in the USA  

E-Print Network [OSTI]

--Aquifer microcosms were used to determine how ethanol and methyl-tert-butyl ether (MtBE) affect monoaromatic compared to benzene, which was degraded only under aerobic conditions. The MtBE was not degraded within 100 to phase out MtBE as a gasoline oxy- genate is likely to significantly increase the use of ethanol

Alvarez, Pedro J.

94

90% of new cars have engines specially designed to run on hydrous ethanol. This avoids the expense of remov-  

E-Print Network [OSTI]

competes with gasoline (petrol), diesel and MTBE (methyl tert-butyl ether, added to gasoline to MTBE, however, ethanol is comparable regarding price per energy unit and has considerable environmental advantages. MTBE is added to gasoline as an octane booster, replac- ing the lead formerly used

95

Critical Reviews in Environmental Science and Technology, 00(0):000000 (2001) 1064-3389/01/$.50  

E-Print Network [OSTI]

water contamination by methyl tert-butyl ether (MTBE) have made policymakers more cognizant of the need reformulated gasoline (RFG) (2% oxygen) year-round to reduce emissions that contribute to ozone formation. MTBE-making process that lead to the widespread use of MTBE over the last decade is now quite controversial (BRP, 1999

Alvarez, Pedro J.

96

Author's personal copy Automobile proximity and indoor residential concentrations of BTEX and MTBE  

E-Print Network [OSTI]

Author's personal copy Automobile proximity and indoor residential concentrations of BTEX and MTBE to indoor benzene and MTBE concentrations appeared to have been dominated by car exhaust concentrations of other BTEX components and methyl tert-butyl ether (MTBE) have been reported [5,6]. Up until

Siegel, Jeffrey

97

Biotreatment of groundwater contaminated with MTBE: interaction of common environmental co-contaminants  

E-Print Network [OSTI]

Biotreatment of groundwater contaminated with MTBE: interaction of common environmental co November 2005 Key words: aerobic, biodegradation, BTEX, co-contaminant, MTBE, TBA Abstract Contamination of groundwater with the gasoline additive methyl tert-butyl ether (MTBE) is often accompanied by many aromatic

98

Canada could get three MTBE plants  

SciTech Connect (OSTI)

This article reports on the proposed development of three methyl tert-butyl ether (MTBE) plants in Canada. MTBE is used as an oxygenated fuel additive. The author discusses how demand for MTBE is increasing due to the regulation of leaded gasoline by the U.S. and Canadian governments. The exportation of MTBE from Canada to the U.S. is highlighted.

Anderson, E

1990-03-01T23:59:59.000Z

99

Fourier Transform Infrared Spectroscopy  

E-Print Network [OSTI]

FTIR - 1 Fourier Transform Infrared Spectroscopy FTIR DETERMINATION OF MTBE IN GASOLINE AND ETHANOL FTIR DETERMINATION OF MTBE IN GASOLINE AND ETHANOL IN VODKA AND MOUTHWASH INTRODUCTION As a part has contained MTBE (methyl tert­butyl ether) as its primary oxygenate. However, there has been

Nizkorodov, Sergey

100

MTBE still facing pressure from ethanol under latest fuel proposal  

SciTech Connect (OSTI)

The US EPA's finalized reformulated gasoline rule, part of Phase II of the 1990 Clean Air Act, signals a possible turnaround for the sluggish methyl tert-butyl ether (MTBE) market. But if a 30% renewable fuels proposal favoring ethanol passes, pressure could continue for MTBE.

Lucas, A.

1994-01-26T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Water Research Institute Annual Technical Report  

E-Print Network [OSTI]

Air Act mandated oxygenated gasoline containing methyl tert-butyl ether (MtBE) in certain areas percent. The State of Maine elected to use reformulated gasoline (RFG) that contained at least 11 percent and by 1995, oxygenated gasoline use was common in the northeast. Soon after the widespread use of gasoline

102

Methyl tertiary butyl ether (MtBE) contamination of the City of Santa Monica drinking water supply  

SciTech Connect (OSTI)

In the summer of 1996, the City of Santa Monica ceased pumping groundwater from two Well Fields (Charnock and Arcadia) used for public drinking water supply due to persistent and increasing concentrations of MtBE in all seven municipal water supply wells. This lost production accounted for 50% of the City`s total drinking water supply. In late 1996, the City, in cooperation with State and Federal agencies, initiated an investigation of MtBE contamination at the two well fields. The objectives of the investigation were as follows: (1) Review available data on the production, use, chemical characteristics, fate and transport, toxicology, and remediation of MtBE; (2) Identify locations of potential sources of MtBE groundwater contamination at the well fields; (3) Develop an understanding of the hydrologic pathways from the potential sources to the drinking water wells; and (4) Evaluate alternative treatment technologies for the removal of MtBE from drinking water. In addition to a review of available information about MtBE, the investigation included an extensive review of literature and available data relevant to the well fields, including well field production histories, site and regional hydrogeology, all well logs and production in the groundwater basins, general groundwater quality, and the record of MtBE detection. Based upon the review of background information, conceptual hydrogeologic models were developed. A detailed review of agency files for over 45 potential source sites was conducted. The information from this review was summarized, and source site screening and ranking criteria were developed. A field program was conducted at the major well field (Charnock), including soil gas surveys, CPTs, soil borings and well installations, geophysics, and aquifer testing. The field program provided site data which allowed the conceptual hydrogeologic model to be refitted to actual site conditions.

Brown, A.; Farrow, J.R.C. [Komex H2O Science, Huntington Beach, CA (United States); Rodriguez, R.A. [City of Santa Monica, CA (United States)] [and others

1997-12-31T23:59:59.000Z

103

Review of potential technologies for the treatment of Methyl tertiary butyl Ether (MtBE) in drinking water  

SciTech Connect (OSTI)

At present, the state of knowledge on effective treatment technologies for MtBE in drinking water, and groundwater in general, is limited. Research by others is focusing on the remediation of MtBE close to the point of release. The City of Santa Monica, MWD, Komex and USC are currently conducting research into different technologies that could be used to remove MtBE from drinking water supplies. The objectives of the research are to evaluate different treatment technologies to identify cost-effective and technically feasible alternatives for the removal of MtBE from drinking water. The evaluation is considering moderate to high water flow rates (100 to 2,000+ gpm) and low to moderate MtBE concentrations (<2,000 {mu}g/l). The research program includes four phases: (1) Literature Review; (2) Bench Scale Study; (3) Field Scale Pre-pilot Study; and (4) Summary Evaluation. This paper presents some preliminary information and findings from the first phase of this research - the literature review. The review discusses the chemical properties of MtBE and how they affect remediation and thus, an evaluation of alternative treatment technologies. The review of available literature, and the applicability and limitations of the following technologies are presented in detail.

Brown, A.; Browne, T.E. [Komex H2O Science, Huntington Beach, CA (United States); Devinny, J.S. [Univ. of Southern California, Los Angeles, CA (United States)] [and others

1997-12-31T23:59:59.000Z

104

Dual expression of hTERT and VEGF prolongs life span and enhances angiogenic ability of aged BMSCs  

SciTech Connect (OSTI)

Highlights: •Expression of hTERT and VEGF changed the lifespan and morphology of hBMSCs. •The expression of VEGF and hTRET promoted angiogenesis in vitro and in vivo. •The expression of VEGF and hTRET in hBMSCs had few effects on tumorigenicity. -- Abstract: Previous studies have confirmed the therapeutic effects of bone marrow stromal cells (BMSCs) transplantation on cerebral ischemia. However, the proliferative, differentiative, and homing capacity of BMSC from the elderly are significantly reduced, especially after several passages expansion in vitro. In this study, by introducing lentivirus-mediated hTERT and VEGF genes to modify human BMSCs from aged donors, we observed extended lifespan, promoted angiogenic capacity while less enhanced tumorigenicity of the genetically engineering BMSCs. These results therefore suggest that the modification of aged BMSCs by dual expression of hTERT and VEGF may be used for autologous cell replacement for ischemic cerebrovascular disease in elderly patients.

Tang, Hao [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China) [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China); Department of Neurosurgery, Affiliated Bayi Brain Hospital, The Military General Hospital of Beijing PLA, Beijing (China); Xiang, Yongsheng [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China) [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China); Department of Neurosurgery, First Affiliated Hospital of Jinan University, Guangzhou (China); Jiang, Xiaodan; Ke, Yiquan; Xiao, Zongyu; Guo, Yang; Wang, Qiujing; Du, Mouxuan; Qin, Linsha; Zou, Yuxi; Cai, Yingqian [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China)] [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China); Chen, Zhenzhou, E-mail: czz1020@163.com [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China)] [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China); Xu, Ruxiang, E-mail: zjxuruxiang@163.com [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China) [Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou (China); Department of Neurosurgery, Affiliated Bayi Brain Hospital, The Military General Hospital of Beijing PLA, Beijing (China)

2013-11-01T23:59:59.000Z

105

Extraction of Plutonium into 30 Percent Tri-Butyl Phosphate from Nitric Acid Solution Containing Fluoride, Aluminum, and Boron  

SciTech Connect (OSTI)

This work consists of experimental batch extraction data for plutonium into 30 volume-percent tri-butyl phosphate at ambient temperature from such a solution matrix and a model of this data using complexation constants from the literature.

Kyser, E.A.

2000-01-06T23:59:59.000Z

106

Aging of Weapon Seals – An Update on Butyl O-ring Issues  

SciTech Connect (OSTI)

During testing under the Enhanced Surveillance Campaign in 2001, preliminary data detected a previously unknown and potentially serious concern with recently procured butyl o-rings on several programs. All butyl o-rings molded from a proprietary formulation throughout the period circa 1999 through 2001 had less than a full cure. Engineering judgment was that under curing is detrimental and could possibly lead to sub-optimum performance or, in the worst case, premature seal failure. An aging study was undertaken to ensure that suspect o-rings installed in the stockpile will retain sufficient sealing force for a minimum ten-year service life. A new prediction model developed for this study indicates suspect o-rings do not need to be replaced before the ten-year service life. Long-term testing results are reported on a yearly basis to validate the prediction model. This report documents the aging results for the period September 2002 to January 2011.

Wilson, Mark H.

2011-07-13T23:59:59.000Z

107

Batch polymerization of styrene initiated by n-butyl lithium in a cyclohexane solvent  

E-Print Network [OSTI]

anionic mechanism. A mathematical model is de- veloped and the predicted values are compared with their corresponding experimental values. Initiator and monomer concentrations are varied and their conversion time profiles are studied. A G&el... and Storage Vessels Purification of Monomer Purification of Solvent Polymerization Reaction Scavenger Level Analysis o f Butyl Lithium Analysis of Molecular Weight Distributions by the Use of Gel Permeation Technique 10 19 19 ZO Zl ZZ 24 25 25...

Landon, Thomas Rodman

1971-01-01T23:59:59.000Z

108

Center for Water Resources Annual Technical Report  

E-Print Network [OSTI]

of Ethanol on Anaerobic Production of Tert-Butyl Alcohol (TBA) from MTBE in Groundwater Kate M. Scow, Douglas

109

Rapid SiO2 Atomic Layer Deposition Using Tris(tert-pentoxy)silanol B. B. Burton,  

E-Print Network [OSTI]

temperatures and higher TPS pressures. SiO2 ALD thicknesses of 125-140 � were observed at the highest TPS requires high temperatures of >325 °C and large reactant exposure of >109 L (1 L ) 10-6 Torr s).4-7 However ALD films using liquid tris(tert-pentoxy)silanol (TPS). The SiO2 film thicknesses were determined

George, Steven M.

110

Detailed chemical kinetic reaction mechanism for biodiesel components methyl stearate and methyl oleate  

E-Print Network [OSTI]

Detailed chemical kinetic reaction mechanism for biodiesel components methyl stearate and methyl are developed for two of the five major components of biodiesel fuel, methyl stearate and methyl oleate renewable sources, can reduce net emissions of greenhouse gases. An important class of biodiesel fuels

Paris-Sud XI, Université de

111

Batch polymerization of styrene and isoprene by n-butyl lithium initiator  

E-Print Network [OSTI]

-20). Analysis of products consists of determining the point at which no free lithium alkyl remains. Thus if a butyl lithium initiated polymerization were terminated with water, butane would be evolved as long as the initiator were present. The butane...? agent were evaporated under a hood. Finally the polymer. was dried in a vacuum oven at about 50'C and under a vacuum of 30 inches of gg for about 30 hours. The weight of polymer formed was determined by final weighing. 25 The monomer conversion...

Hasan, Sayeed

1970-01-01T23:59:59.000Z

112

A kinetic investigation of the reaction of dibutyl sodiophosphonate with n-butyl bromide  

E-Print Network [OSTI]

of Texn~ in partial fulfillment of the requirements for the de ree of MASTER OF SCIENCE August 1955 Major Subject: Chemistry A KINETIC INVESTIGATION OF THE REACTION OF DIBUTYL SODIOPHOSPHONATE WITH N-BUTYL BROMIDE A Thesis By James Howard Shaffer... Concentrations o " Reactants and Calculated Second Order Specific Reaction pa, ". ;e Rate Constants Table 1, 40 C Table 2, 50 0 Table 3, BO C 3c II. Initial Concentrations of React iit : ?d Apparent Rate Constants of Erofosed Die er 1!echani sm Table 4...

Shaffer, James Howard

1955-01-01T23:59:59.000Z

113

Saudi MTBE project revived  

SciTech Connect (OSTI)

Alujain Corp., a member of the Xenel group of Saudi Arabia, is going ahead with plans to build an 800,000-m.t./year methyl tert-butyl ether (MTBE) plant. Bechtel has been appointed project manager for the plant, which will be owned by a new company, National Fuel Additives (Tahseen). Bechtel will help evaluate proposals already submitted for the lump sum turnkey job.

NONE

1996-01-17T23:59:59.000Z

114

MTBE from butadiene-rich C/sub 4/s  

SciTech Connect (OSTI)

Methyl tert-butyl ether (MTBE), is made by reacting methanol with isobutylene. The preferred source of isobutylene is a steam cracker C/sub 4/ cut from which butadiene has been removed. However, moving the MTBE synthesis upstream of the butadiene extraction will improve the extraction step. The following is a review of conditions imposed on the MTBE unit's design and operation when placed in this new location.

Ancillotti, F.; Pescarollo, E.; Szatmari, E.; Lazar, L.

1987-12-01T23:59:59.000Z

115

Detailed Chemical Kinetic Reaction Mechanism for Biodiesel Components Methyl Stearate and Methyl Oleate  

SciTech Connect (OSTI)

New chemical kinetic reaction mechanisms are developed for two of the five major components of biodiesel fuel, methyl stearate and methyl oleate. The mechanisms are produced using existing reaction classes and rules for reaction rates, with additional reaction classes to describe other reactions unique to methyl ester species. Mechanism capabilities were examined by computing fuel/air autoignition delay times and comparing the results with more conventional hydrocarbon fuels for which experimental results are available. Additional comparisons were carried out with measured results taken from jet-stirred reactor experiments for rapeseed methyl ester fuels. In both sets of computational tests, methyl oleate was found to be slightly less reactive than methyl stearate, and an explanation of this observation is made showing that the double bond in methyl oleate inhibits certain low temperature chain branching reaction pathways important in methyl stearate. The resulting detailed chemical kinetic reaction mechanism includes more approximately 3500 chemical species and more than 17,000 chemical reactions.

Naik, C; Westbrook, C K; Herbinet, O; Pitz, W J; Mehl, M

2010-01-22T23:59:59.000Z

116

Tests for mutagenic effects of ammoniated glycyrrhizin, butylated hydroxytoluene, and gum arabic in roden germ cells  

SciTech Connect (OSTI)

Ammoniated glycyrrhizin, butylated hydroxytoluene, and gum Arabic are generally recognized as safe (GRAS) substances that are used primarily as additives in foods. These substances were incorporated into rodent diets and fed to male rats and mice for 10 and 8 wk, respectively. The treated male mice and rats were then tested for dominant lethal effects. The mice were also tested for induced heritable translocation. Results of the rat studies indicated a statistically significant dominant lethal effect of each of the compounds tested; however, the biological significance of this response is not known. Results of the mouse dominant lethal and heritable translocation studies, on the other hand, indicated no adverse effects of the compounds tested.

Sheu, C.W.; Cain, K.T.; Rushbrook, C.J.; Jorgenson, T.A.; Generoso, W.M.

1986-01-01T23:59:59.000Z

117

Initiation Temperature for Runaway Tri-n-Butyl Phosphate/Nitric Acid Reaction  

SciTech Connect (OSTI)

In a review of the safety basis for solvent extraction processes at the Department of Energy's Savannah River Site, a question was raised concerning the safety margin associated with a postulated accident involving a runaway tri-n-butyl phosphate (TBP)/nitric acid reaction due to the inadvertent heating of a tank. The safety margin was based on studies which showed the maximum temperature would not exceed 128 degrees Celsius compared to 130 degrees Celsius, the minimum initiation temperature for runaway reaction established in the 1950's following damaging incidents at the Savannah River and Hanford Sites. The reviewers were concerned the minimum temperature was not conservative since data for solutions containing 20 wt percent dissolved solids showed initiation temperatures at or below 130 degrees Celsius and process solutions normally contain some dissolved solids.

Rudisill, T.S.

2001-09-14T23:59:59.000Z

118

A thermodynamic model of nitric acid extraction by tri-n-butyl phosphate  

SciTech Connect (OSTI)

A thermodynamic model is presented for nitric acid extraction by tri-n-butyl phosphate (TBP). This model is based on the formation of the organic phase species: TBP.HNO/sub 3/ and (TBP)/sub 2/.HNO/sub 3/. The model works successfully at TBP concentrations of 5 to 100 vol% and was found to be effective at predicting the extraction of HNO/sub 3/ from HNO/sub 3//NaNO/sub 3/ and HNO/sub 3//LiNO/sub 3/ solutions. Within the TBP concentration range of 5 to 30%, a single set of extraction constants was sufficient to fit extraction data. Stoichiometric activity coefficients of nitric acid in HNO/sub 3//NaNO/sub 3/ and HNO/sub 3//LiNO/sub 3/ mixtures were calculated using a model developed by Bromley.

Chaiko, D.J.; Vandegrift, G.F.

1988-07-01T23:59:59.000Z

119

Green polymer electrolytes based on chitosan and 1-butyl-3-methylimidazolium acetate  

SciTech Connect (OSTI)

Green polymer electrolytes based on chitosan as the polymer matrix and ionic liquid 1-butyl-3-methylimidazolium acetate [Bmim][OAc] as charge carriers were prepared by solution casting technique. Complexes with various amount of ionic liquid loading were investigated as possible ionic conducting polymers. The ionic conductivity was found to increase with increasing weight percent of ionic liquid. The highest ionic conductivity of the charged chitosan-[Bmim][OAc] was 2.44 × 10{sup ?3} S cm{sup ?1} at 90 wt.% of [Bmim][OAc] content at ambient temperature. Attenuated Total Reflection Fourier Transform infrared (ATR-FTIR) spectroscopy has proven the interaction between chitosan and [Bmim][OAc]. X-ray Diffraction (XRD) has shown that the amorphosity of the complexes increase as the amount of [Bmim][OAc] increase.

Shamsudin, Intan Juliana [Chemistry Department, Centre for Defence Foundation Studies, National Defence University of Malaysia, 57000 Kuala Lumpur (Malaysia); Ahmad, Azizan; Hassan, Nur Hasyareeda [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan (Malaysia)

2014-09-03T23:59:59.000Z

120

Analysis of dissolved benzene plumes and methyl tertiary butyl ether (MTBE) plumes in ground water at leaking underground fuel tank (LUFT) sites  

SciTech Connect (OSTI)

The 1990 Clean Air Act Amendments mandate the addition of oxygenates to gasoline products to abate air pollution. Currently, many areas of the country utilize oxygenated or reformulated fuel containing 15- percent and I I-percent MTBE by volume, respectively. This increased use of MTBE in gasoline products has resulted in accidental point source releases of MTBE containing gasoline products to ground water. Recent studies have shown MTBE to be frequently detected in samples of shallow ground water from urban areas throughout the United States (Squillace et al., 1995). Knowledge of the subsurface fate and transport of MTBE in ground water at leaking underground fuel tank (LUFT) sites and the spatial extent of MTBE plumes is needed to address these releases. The goal of this research is to utilize data from a large number of LUFT sites to gain insights into the fate, transport, and spatial extent of MTBE plumes. Specific goals include defining the spatial configuration of dissolved MTBE plumes, evaluating plume stability or degradation over time, evaluating the impact of point source releases of MTBE to ground water, and attempting to identify the controlling factors influencing the magnitude and extent of the MTBE plumes. We are examining the relationships between dissolved TPH, BTEX, and MTBE plumes at LUFT sites using parallel approaches of best professional judgment and a computer-aided plume model fitting procedure to determine plume parameters. Here we present our initial results comparing dissolved benzene and MTBE plumes lengths, the statistical significance of these results, and configuration of benzene and MTBE plumes at individual LUFT sites.

Happel, A.M.; Rice, D. [Lawrence Livermore National Lab., CA (United States); Beckenbach, E. [California Univ., Berkeley, CA (United States); Savalin, L.; Temko, H.; Rempel, R. [California State Water Resources Control Board, Sacramento, CA (United States); Dooher, B. [California Univ., Los Angeles, CA (United States)

1996-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Influence of the host cell factors CK2, hTERT, and PML, on the antiviral response to herpes simplex virus type I infection  

E-Print Network [OSTI]

deploys a variety of defenses to limit the extent to which the virus can replicate. This thesis is the summation of projects that examined the impact of three host cell factors - those being CK2, hTERT, and PML - on HSV-1 replication. CK2 is a cellular...

Smith, Miles Christian

2013-08-31T23:59:59.000Z

122

Anhydrous aluminum chloride as an alkylation catalyst: identification of mono- and dialkyl-benzenes from the condensation of tertiary butyl alcohol with benzene.  

E-Print Network [OSTI]

LIBRARY a a w c"I. I. SI - O~ TI:YAf ANHYDROUS ALUMINUM CHLORIDE AS AN ALKYLATION CATALYST: IDENTIFICATION OF MONO- AND DIALKYIZENZENES FROM THE CONDENSATION QF TERTIARY BUTYL ALCOHOL WITH BENKENE IACEY EUGENE SCOGGINS 4 A Thesis Submitted...: IDENTIFICATION OF MONO- AND DI~NZZNES FROM THE CONDENSATION OF TERTIARY BUTYL ALCOHOL WITH BENZENE A Thesis By LACEY EUGENE SCOGGINS Approved as to style and content hy: Chairman of Committee Head of Chemistry Department 1959 ACKNOWLEDGME1VTS The author...

Scoggins, Lacey E

1959-01-01T23:59:59.000Z

123

Isothermal vapor-liquid equilibria for 2-methyl-2-butanol + 2-methyl-1-butanol + 1-pentanol  

SciTech Connect (OSTI)

Vapor-liquid equilibria (VLE) for 2-methyl-2-butanol + 2-methyl-1-butanol and 2-methyl-2-butanol + 2-methyl-1-butanol + 1-pentanol have been measured at 373.15 K. The binary VLE results have been correlated by different liquid-phase activity coefficient models. The binary interaction parameters obtained from Wilson, NRTL, and UNIQUAC models in this and a previously study are used to predict the VLE data for the ternary system. Vapor-liquid equilibrium (VLE) data are necessary for the design of distillation processes.

Aucejo, A.; Burguet, M.C.; Monton, J.B.; Munoz, R.; Sanchotello, M.; Vazquez, M.I. (Univ. of Valencia (Spain). Dept. de Ingenieria Quimica)

1994-07-01T23:59:59.000Z

124

Initiation Temperature for Runaway Tri-n-Butyl Phosphate/Nitric Acid Reaction  

SciTech Connect (OSTI)

During a review of the H-Canyon authorization basis, Defense Nuclear Facility Safety Board (DNFSB) staff members questioned the margin of safety associated with a postulated tri-n-butyl phosphate (TBP)/nitric acid runaway reaction due to the inadvertent heating of a canyon tank containing greater than 3000 lbs (1362 kg) of TBP. The margin of safety was partially based on experiments and calculations performed by the Actinide Technology Section (ATS) to support deletion of indication of tank agitation as a Safety Class System. In the technical basis for deletion of this system, ATS personnel conservatively calculated the equilibrium temperature distribution of a canyon tank containing TBP and nitric acid layers which were inadvertently heated by a steam jet left on following a transfer. The maximum calculated temperature (128 degrees C) was compared to the minimum initiation temperature for a runaway reaction (greater than 130 degrees C) documented by experimental work in the mid 195 0s. In this work, the initiation temperature as a function of nitric acid concentration was measured for 0 and 20 wt percent dissolved solids. The DNFSB staff members were concerned that data for 0 wt percent dissolved solids were not conservative given the facts that data for 20 wt percent dissolved solids show initiation temperatures at or below 130 degrees C and H-Canyon solutions normally contained a small amount of dissolved solids.

Rudisill, T.S.

2000-11-28T23:59:59.000Z

125

Thorium ions transport across Tri-n-butyl phosphate-benzene based supported liquid membranes  

SciTech Connect (OSTI)

Transport of Th(IV) ions across tri-n-butyl phosphate (TBP) benzene based liquid membranes supported in microporous hydrophobic polypropylene film (MHPF) has been studied. Various parameters such as variation of nitric acid concentration in the feed, TBP concentration in the membrane, and temperature on the given metal ions transport have been investigated. The effects of nitric acid and TBP concentrations on the distribution coefficient were also studied, and the data obtained were used to determine the Th ions-TBP complex diffusion coefficient in the membrane. Permeability coefficients of Th(IV) ions were also determined as a function of the TBP and nitric acid concentrations. The optimal conditions for the transport of Th(IV) ions across the membrane are 6 mol{sm_bullet}dm{sup -3} HNO{sub 3} concentration, 2.188 mol {center_dot} dm{sup -3} TBP concentration, and 25{degrees}C. The stoichiometry of the chemical species involved in chemical reaction during the transport of Th(IV) ions has also been studied.

Rasul, G.; Chaudry, M.A. [Pakistan Institute of Nuclear Chemistry, Islamabad (Pakistan); Afzal, M. [Quaid-I-Azam Univ., Islamabad (Pakistan)

1995-12-01T23:59:59.000Z

126

Determination of Total Lipids as Fatty Acid Methyl Esters (FAME...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

will be replaced by an ester bond between the fatty acid and a methyl group, producing methyl esters of the fatty acids (FAME) and free glycerol. 1.4 The FAME are then...

127

Comparative Dynamics of Leucine Methyl Groups in FMOC-Leucine...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Dynamics of Leucine Methyl Groups in FMOC-Leucine and in a ProteinHydrophobic Core Probed by Solid-State Deuteron Comparative Dynamics of Leucine Methyl Groups in FMOC-Leucine and...

128

Sub-millimeter sized methyl butanoate droplet combustion: Microgravity experiments  

E-Print Network [OSTI]

-dependent, sphero-symmetric droplet combustion simulation that includes detailed gas phase chemical kineticsSub-millimeter sized methyl butanoate droplet combustion: Microgravity experiments and detailed 2012 Abstract Combustion characteristics of isolated sub-millimeter sized methyl butanoate (MB

Walter, M.Todd

129

Vapor-liquid equilibria for systems of 1-butanol with 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol, and 3-methyl-2-butanol at 30 and 100 kPa  

SciTech Connect (OSTI)

Vapor-liquid equilibrium data were measured for binary systems of 1-butanol with 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol, and 3-methyl-2-butanol at 30 and 100 kPa. The experimental data obtained in this work are thermodynamically consistent according to a point-to-point consistency test, and deviation from ideal behavior is small in all cases. They can be equally well correlated with the Margules, Van Laar, Wilson, NRTL, and UNIQUAC equations.

Aucejo, A.; Burguet, M.C.; Monton, J.B.; Munoz, R.; Sanchotello, M.; Vazquez, M.I. (Univ. de Valencia (Spain). Dept. de Ingenieria Quimica)

1994-04-01T23:59:59.000Z

130

E-Print Network 3.0 - amplified methylation polymorphism Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Environmental Sciences and Ecology 2 Infraspecific DNA Methylation Polymorphism in Cotton (Gossypium Summary: Infraspecific DNA Methylation Polymorphism in Cotton (Gossypium...

131

Biomass burning and urban air pollution over the Central Mexican Plateau  

E-Print Network [OSTI]

the urban tracers (e.g. C 2 H 2 , MTBE, toluene) are highlymethyl tert-butyl ether (MTBE) because their shorter atmo-

2009-01-01T23:59:59.000Z

132

First Annual U.S. Department of Energy Office of Science Joint Genome Institute User Meeting  

E-Print Network [OSTI]

Genome Analysis of MTBE-Degrading Beta- Proteobacteriummethyl tert- butyl ether (MTBE). Strain PM1 can alsooften co-contaminants with MTBE in groundwater, including

Various

2006-01-01T23:59:59.000Z

133

Oxidation and methylation of dissolved elemental mercury by anaerobic bacteria  

SciTech Connect (OSTI)

Methylmercury is a neurotoxin that poses significant health risks to humans. Some anaerobic sulphate- and iron-reducing bacteria can methylate oxidized forms of mercury, generating methylmercury1-4. One strain of sulphate-reducing bacteria (Desulfovibrio desulfuricans ND132) can also methylate elemental mercury5. The prevalence of this trait among different bacterial strains and species remains unclear, however. Here, we compare the ability of two strains of the sulphate-reducing bacterium Desulfovibrio and one strain of the iron-reducing bacterium Geobacter to oxidise and methylate elemental mercury in a series of laboratory incubations. Experiments were carried out under dark, anaerobic conditions, in the presence of environmentally-relevant concentrations of elemental mercury. We report differences in the ability of these organisms to oxidise and methylate elemental mercury. In line with recent findings5, we show that Desulfovibrio desulfuricans ND132 can both oxidise and methylate elemental mercury. However, the rate of methylation of elemental mercury is only about one third the rate of methylation of oxidized mercury. We also show that Desulfovibrio alaskensis G20 can oxidise, but not methylate, elemental mercury. Geobacter sulfurreducens PCA is able to oxidise and methylate elemental mercury in the presence of cysteine. We suggest that the activity of methylating and non-methylating bacteria may together enhance the formation of methylmercury in anaerobic environments.

Hu, Haiyan [ORNL] [ORNL; Lin, Hui [ORNL] [ORNL; Zheng, Wang [ORNL] [ORNL; Tomanicek, Stephen J [ORNL] [ORNL; Johs, Alexander [ORNL] [ORNL; Feng, Xinbin [ORNL] [ORNL; Elias, Dwayne A [ORNL] [ORNL; Liang, Liyuan [ORNL] [ORNL; Liang, Liyuan [ORNL] [ORNL; Gu, Baohua [ORNL] [ORNL

2013-01-01T23:59:59.000Z

134

Health concerns fuel EPA study of ETBE and TAME  

SciTech Connect (OSTI)

Citing possible health risks associated with the use of methyl tert-butyl ether (MTBE) in winter-blend gasoline and requirements of the 1990 Clean Air Act (CAA), EPA has called for testing the health effects of ethyl tert-butyl ether (EBTE) and tert-amyl methyl ether (TAME). The program calls for toxicity testing to develop data on the health effects of ETBE and TAME. EPA may require chemical manufacturers and processors to provide the data. A public meeting will be held this week to begin working on an agreement. EPA says most of the data should be collected in 1995 and expects the program to cost approximately $3 million. In December, EPA floated a proposal to require 30% of the oxygenates used in the reformulated gasoline program to come from renewable sources such as ETBE and ethanol. Although EPA found no serious health risks associated with MTBE, questions remain, which is why EPA says it will test the use of ETBE and TAME. William Piel, business manager for oxygenated fuels at Arco Chemical (Newtown Square, PA), says testing is {open_quotes}just a formality.{close_quotes} There should be no difference in results among MTBE, ETBE, or TAME, he says. But ETBE and TAME have much lower volatility than MTBE, which would mean significantly less exposure to these oxygenates, Piel says. Arco is the biggest producer of MTBE but also has capability to make ETBE.

Lucas, A.

1994-05-11T23:59:59.000Z

135

Radiation chemistry of alternative fuel oxygenates -- Substituted ethers  

SciTech Connect (OSTI)

The electron beam process, an advanced oxidation and reduction technology, is based in the field of radiation chemistry. Fundamental to the development of treatment processes is an understanding of the underlying chemistry. The authors have previously evaluated the bimolecular rate constants for the reactions of methyl tert-butyl ether (MTBE) and with this study have extended their studies to include ethyl tert-butyl ether (ETBE), di-isopropyl ether (DIPE) and tert-amyl methyl ether (TAME) with the hydroxyl radical, hydrogen atom and solvated electron using pulse radiolysis. For all of the oxygenates the reaction with the hydroxyl radical appears to be of primary interest in the destruction of the compounds in water. The rates with the solvated electron are limiting values as the rates appear to be relatively low. The hydrogen atom rate constants are relatively low, coupled with the low yield in radiolysis, they concluded that these are of little significance in the destruction of the alternative fuel oxygenates (and MTBE).

Mezyk, S. P.; Cooper, W. J.; Bartels, D. M.; Tobien, T.; O'Shea, K. E.

1999-11-15T23:59:59.000Z

136

Successful Pregnancy with a Full-Term Vaginal Delivery One Year After n-Butyl Cyanoacrylate Embolization of a Uterine Arteriovenous Malformation  

SciTech Connect (OSTI)

Uterine arteriovenous malformation (AVM) causes significant morbidity with vaginal bleeding. Traditional therapy is a hysterectomy with no potential for future pregnancy. We present a case of successful superselective embolization of uterine AVM using n-butyl cyanoacrylate with subsequent normal term pregnancy and uncomplicated vaginal delivery in 1 year.

McCormick, Colleen C. [Johns Hopkins University School of Medicine, Department of Gynecology and Obstetrics (United States); Kim, Hyun S. [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science (United States)], E-mail: sikhkim@jhmi.edu

2006-08-15T23:59:59.000Z

137

Capture isobutylene with glycol  

SciTech Connect (OSTI)

The separation of butenes present in C-4 streams (generated as a result of steam or catalytic cracking) is becoming increasingly important as the butenes find expanded applications in the production of methyl-t-butyl ether (MTBE), methyl methacrylate, butyl rubber, and linear low-density polyethylene. Available methods of separation include selective extraction with a liquid solvent (usually an acid); the use of addition reactions with suitable alcohols, acids, or water; selective polymerization and physical separation by absorbents. Three currently important separation processes for isobutylene production are an extraction route using mineral acid, the dehydration of tert-butanol, and the cracking of MTBE. As part of the research into solid acid catalysis for the generation of glycol tert-butyl monoethers, the authors have demonstrated an alternative C-4 separation process using solid inorganic acid catalysts and involving the intermediate preparation of glycol ethers. This new C-4 separation scheme could be particularly attractive to existing glycol producers who may also have a market, or internal need, for glycol monoalkyl ethers, as well as those who do not have MTBE capacity but still require pure isobutylene as a chemical intermediate or comonomer building block. The process is described.

Knifton, J.F. (Texaco Chemical's Austin Research Lab. TX (United States))

1994-05-01T23:59:59.000Z

138

An Experimental and Kinetic Modeling Study of Methyl Decanoate Combustion  

SciTech Connect (OSTI)

Biodiesel is typically a mixture of long chain fatty acid methyl esters for use in compression ignition engines. Improving biofuel engine performance requires understanding its fundamental combustion properties and the pathways of combustion. This research study presents new combustion data for methyl decanoate in an opposed-flow diffusion flame. An improved detailed chemical kinetic model for methyl decanoate combustion is developed, which serves as the basis for deriving a skeletal mechanism via the direct relation graph method. The novel skeletal mechanism consists of 648 species and 2998 reactions. This mechanism well predicts the methyl decanoate opposed-flow diffusion flame data. The results from the flame simulations indicate that methyl decanoate is consumed via abstraction of hydrogen atoms to produce fuel radicals, which lead to the production of alkenes. The ester moiety in methyl decanoate leads to the formation of low molecular weight oxygenated compounds such as carbon monoxide, formaldehyde, and ketene.

Sarathy, S M; Thomson, M J; Pitz, W J; Lu, T

2010-02-19T23:59:59.000Z

139

Methyl viologen radical reactions with several oxidizing agents. [Gamma Radiation  

SciTech Connect (OSTI)

The rates of oxidation of the methyl viologen radical by peroxodisulfate and hydrogen peroxide has been investigated. The methyl viologen free radical was produced by pulse radiolysis. The reaction of the peroxodisulfate radical with the methyl viologen radical was first order in both species, and the reaction rate constant is reported. A el-radiation study revealed a chain decomposition of the peroxodisulfate radical involving the methyl viologen radical when methanol, ethanol, or 2-propanol was present. Loss of the methyl viologen radical was then no longer observed to be a simple first-order reaction. The reaction of hydrogen peroxide with the methyl viologen radical was very slow in the presence of 1 M methanol. A much faster reaction in the absence of methanol was interpreted to be a reaction of the methyl viologen radical with the peroxy radicals. Hydrogen peroxide, in contrast to the chain decomposition of peroxodisulfate radicals, does not participate in a chain reaction involving the methyl viologen radical and methanol. Rate constants for the reaction of methyl viologen radical with dichromate radical, iodate radical, and ferricyanide radical are reported.

Levey, G.; Ebbesen, T.W.

1983-01-01T23:59:59.000Z

140

Health studies indicate MTBE is safe gasoline additive  

SciTech Connect (OSTI)

Implementation of the oxygenated fuels program by EPA in 39 metropolitan areas, including Fairbanks and Anchorage, Alaska, in the winter of 1992, encountered some unexpected difficulties. Complaints of headaches, dizziness, nausea, and irritated eyes started in Fairbanks, jumped to Anchorage, and popped up in various locations in the lower 48 states. The suspected culprit behind these complaints was the main additive for oxygenation of gasoline is methyl tert-butyl ether (MTBE). A test program, hastily organized in response to these complaints, has indicated that MTBE is a safe gasoline additive. However, official certification of the safety of MTBE is still awaited.

Anderson, E.V.

1993-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Veba in MTBE project, cutting aromatics  

SciTech Connect (OSTI)

The new owners of the refinery and petrochemical complex at Schwedt in eastern Germany-RWE-DEA (Hamburg), Veba Oel (Gelsenkirchen), Agip (Rome), Total (Paris), and Elf-Aquitaine (Paris)-plan to build a 60,000-m.t./year methyl tert-butyl ether (MTBE) plant at the site for 1994-1995 completion. The MTBE project forms part of the consortium`s announced DM1.5-billion ($500 million) investment program for the complex that aims to raise refinery throughput from 8 million m.t./year to 12 million m.t./year by 1994 and hike production of naphtha and benzene.

Young, I.; Roberts, M.

1992-04-15T23:59:59.000Z

142

MTBE growth limited despite lead phasedown in gasoline  

SciTech Connect (OSTI)

This month's legislated reduction of the allowable amount of lead additives in gasoline will increase demand strongly for methyl-tert-butyl ether (MTBE) as an octane enhancer, but the economics of the refinery business and the likelihood of rapidly increasing high-octane gasoline imports probably will limit the size of the business in coming years. MTBE will be used to fill the octane gap now, but economics and imports of gasoline later on could hold down demand. The limited growth in sales of MTBE is discussed.

Storck, W.

1985-07-15T23:59:59.000Z

143

Synthesis of octane enhancer during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 4, July 1, 1991--September 30, 1991  

SciTech Connect (OSTI)

The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. Addition of methanol to slurry phase FT synthesis making iso-olefins.

Marcelin, G.

1991-12-15T23:59:59.000Z

144

MTBE: Capacity boosts on hold amid demand concerns  

SciTech Connect (OSTI)

Uncertainty reigns in the methyl tert-butyl ether (MTBE) market. {open_quotes}We have no choice but to put our expansion plans on the back burner,{close_quotes} says one producer. {open_quotes}Because of government actions, there are no MTBE plants being built or expanded.{close_quotes} Spot MTBE prices have risen ti 82 cts- 83 cts/gal from 76 cts-78 cts/gal earlier this month as the demand for octane enhancement increases for the summer driving season. Some observers say EPA may relax different oxygen requirements for gasoline in different seasons. That would simplify production and supply for MTBE makers.

NONE

1995-05-03T23:59:59.000Z

145

Methanex considers methanol, MTBE in Qatar  

SciTech Connect (OSTI)

CW has learned that Methanex Corp. is considering entering one of two methanol and methyl tert-butyl ether (MTBE) projects in Qatar. Executive v.p. Michael Wilson says that part of the company`s New Zealand plant could be moved to a site in Qatar, which would lower capital costs for the possible project by $75 million-$100 million. Both Qatar General Petroleum Corp. and Qatar Fuel Additives are developing methanol and MTBE projects at Umm Said, Qatar. Methanex says its goal is to ensure low-cost feedstocks.

NONE

1995-12-13T23:59:59.000Z

146

Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 5, October 1, 1991--December 31, 1991  

SciTech Connect (OSTI)

The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. Addition of methanol to slurry phase FT synthesis making iso-olefins.

Marcelin, G.

1992-06-10T23:59:59.000Z

147

Total to withdraw from Qatar methanol - MTBE?  

SciTech Connect (OSTI)

Total is rumored to be withdrawing from the $700-million methanol and methyl tert-butyl ether (MTBE) Qatar Fuel Additives Co., (Qafac) project. The French company has a 12.5% stake in the project. Similar equity is held by three other foreign investors: Canada`s International Octane, Taiwan`s Chinese Petroleum Corp., and Lee Change Yung Chemical Industrial Corp. Total is said to want Qafac to concentrate on methanol only. The project involves plant unit sizes of 610,000 m.t./year of MTBE and 825,000 m.t./year of methanol. Total declines to comment.

NONE

1996-05-01T23:59:59.000Z

148

ORTH/VIM proteins that regulate DNA methylation are functional ubiquitin E3 ligases  

E-Print Network [OSTI]

ORTH/VIM proteins that regulate DNA methylation are functional ubiquitin E3 ligases Edward Kraft1 methylation status in vivo. Keywords: RING, E3 ligase, DNA methylation, ubiquitylation, ORTH/VIM, SRA

Jacobsen, Steve

149

Host cells and methods for producing 3-methyl-2-buten-1-ol, 3-methyl-3-buten-1-ol, and 3-methyl-butan-1-ol  

DOE Patents [OSTI]

The invention provides for a method for producing a 5-carbon alcohol in a genetically modified host cell. In one embodiment, the method comprises culturing a genetically modified host cell which expresses a first enzyme capable of catalyzing the dephosphorylation of an isopentenyl pyrophosphate (IPP) or dimethylallyl diphosphate (DMAPP), such as a Bacillus subtilis phosphatase (YhfR), under a suitable condition so that 5-carbon alcohol is 3-methyl-2-buten-1-ol and/or 3-methyl-3-buten-1-ol is produced. Optionally, the host cell may further comprise a second enzyme capable of reducing a 3-methyl-2-buten-1-ol to 3-methyl-butan-1-ol, such as a reductase.

Chou, Howard H. (Berkeley, CA); Keasling, Jay D. (Berkeley, CA)

2011-07-26T23:59:59.000Z

150

Use of ferric sulfate: acid media for the desulfurization of model compounds of coal. [Dibenzothiophene, diphenyl sulfide, di-n-butyl sulfide  

SciTech Connect (OSTI)

The objective of this work has been to investigate the ability of ferric sulfate-acid leach systems to oxidize the sulfur in model compounds of coal. Ferric iron-acid leach systems have been shown to be quite effective at removal of inorganic sulfur in coal. In this study, the oxidative effect of ferric iron in acid-leach systems was studied using dibenzothiophene, diphenyl sulfide, and di-n-butyl sulfide as models of organic sulfur groups in coal. Nitrogen and oxygen, as well as various transition metal catalysts and oxidants, were utilized in this investigation. Dibenzothiophene was found to be quite refractory to oxidation, except in the case where metavanadate was added, where it appears that 40% oxidation to sulfone could have occurred per hour at 150/sup 0/C and mild oxygen pressure. Diphenyl sulfide was selectively oxidized to sulfoxide and sulfone in an iron and oxygen system. Approximately 15% conversion to sulfone occurred per hour under these conditions. Some of the di-n-butyl sulfide was cracked to 1-butene and 1-butanethiol under similar conditions. Zinc chloride and ferric iron were used at 200/sup 0/C in an attempt to desulfonate dibenzothiophene sulfone, diphenyl sulfone, and di-n-butyl sulfone. Di-n-butyl sulfone was completely desulfurized on one hour and fragmented to oxidized parafins, while dibenzothiophene sulfone and diphenyl sulfone were unaffected. These results suggest that an iron-acid leach process could only selectively oxidize aryl sulfides under mild conditions, representing only 20% of the organic sulfur in coal (8% of the total sulfur). Removal through desulfonation once selective sulfur oxidation had occurred was only demonstrated for alkyl sulfones, with severe oxidation of the fragmented paraffins also occurring in one hour.

Clary, L.R.; Vermeulen, T.; Lynn, S.

1980-12-01T23:59:59.000Z

151

Identification of volatile butyl rubber thermal-oxidative degradation products by cryofocusing gas chromatography/mass spectrometry (cryo-GC/MS).  

SciTech Connect (OSTI)

Chemical structure and physical properties of materials, such as polymers, can be altered as aging progresses, which may result in a material that is ineffective for its envisioned intent. Butyl rubber formulations, starting material, and additives were aged under thermal-oxidative conditions for up to 413 total days at up to 124 %C2%B0C. Samples included: two formulations developed at Kansas City Plant (KCP) (%236 and %2310), one commercially available formulation (%2321), Laxness bromobutyl 2030 starting material, and two additives (polyethylene AC-617 and Vanax MBM). The low-molecular weight volatile thermal-oxidative degradation products that collected in the headspace over the samples were preconcentrated, separated, and detected using cryofocusing gas chromatography mass spectrometry (cryo-GC/MS). The majority of identified degradation species were alkanes, alkenes, alcohols, ketones, and aldehydes. Observations for Butyl %2310 aged in an oxygen-18 enriched atmosphere (18O2) were used to verify when the source of oxygen in the applicable degradation products was from the gaseous environment rather than the polymeric mixture. For comparison purposes, Butyl %2310 was also aged under non-oxidative thermal conditions using an argon atmosphere.

Smith, Jonell Nicole; White, Michael Irvin; Bernstein, Robert; Hochrein, James Michael

2013-02-01T23:59:59.000Z

152

Energy Efficiency Improvement and Cost Saving Opportunities for the Petrochemical Industry - An ENERGY STAR(R) Guide for Energy and Plant Managers  

E-Print Network [OSTI]

Ethylene dichloride 1 MTBE 2 Vinylchloride 3 Ethylbenzene 1Methyl- Tertiary-Butyl-Ether (MTBE) or Ethyl-Tertiary-Butyl-Styrene Vinylchloride MTBE Benzene, Toluene, Xylene Acetone

Neelis, Maarten

2008-01-01T23:59:59.000Z

153

E-Print Network 3.0 - arsenic methylation profiles Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: , urinary arsenic methylation profiles, and urothelial carcinoma susceptibility. Food Chem. Toxicol. 46, 929... and in vitro studies suggest that methylated arsenic...

154

Molecular Dynamics Simulations of Tri-n-butyl-phosphate/n-Dodecane Mixture: Thermophysical Properties and Molecular Structure  

SciTech Connect (OSTI)

Molecular dynamics simulations of tri-n-butyl-phosphate (TBP)/n-dodecane mixture in the liquid phase have been carried out using two recently developed TBP force field models (J. Phys. Chem. B 2012, 116, 305) in combination with the all-atom optimized potentials for liquid simulations (OPLS-AA) force field model for n-dodecane. Specifically, the electric dipole moment of TBP, mass density of the mixture, and the excess volume of mixing were computed with TBP mole fraction ranging from 0 to 1. It is found that the aforementioned force field models accurately predict the mass density of the mixture in the entire mole fraction range. Commensurate with experimental measurements, the electric dipole moment of the TBP was found to slightly increase with the mole fraction of TBP in the mixture. Also, in accord with experimental data, the excess volume of mixing is positive in the entire mole fraction range, peaking at TBP mole fraction range 0.3 0.5. Finally, a close examination of the spatial pair correlation functions between TBP molecules, and between TBP and n-dodecane molecules, revealed formation of TBP dimers through self-association at close distance, a phenomenon with ample experimental evidence.

de Almeida, Valmor F [ORNL; Cui, Shengting [ORNL; Khomami, Bamin [ORNL

2014-01-01T23:59:59.000Z

155

Methyl bromide emissions to the atmosphere from temperate woodland ecosystems   

E-Print Network [OSTI]

The environmental importance of methyl bromide (CH3Br) arises from its contribution to stratospheric ozone loss processes and, as a consequence, its emissions from anthropogenic sources are subject to the Montreal Protocol. A better understanding...

Drewer, Julia; Heal, Kate V; Smith, Keith A; Heal, Mathew R

2008-01-01T23:59:59.000Z

156

The Genetics of de novo Methylation in Arabidopsis thaliana  

E-Print Network [OSTI]

domains akin to UHRF1 and the VIM proteins. These proteinsthe VARIANT IN METHYLATION (VIM) family. In higher orderUHRF1 in mammal or the VIM proteins in plants. UHRF1/VIM

Greenberg, Maxim Van Cleef

2012-01-01T23:59:59.000Z

157

Regulation of yeast development by mRNA methylation  

E-Print Network [OSTI]

The internal methylation of mRNA post-transcriptionally is an essential component of the mRNA editing machinery in virtually every eukaryotic system. Despite this ubiquity, little is known about the relevance, consequences ...

Agarwala, Sudeep D

2012-01-01T23:59:59.000Z

158

akap12 promoter methylation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(MEK) with hydrogen peroxide (H2O2), is widely used in industry as a radicalThermal Hazard Analysis of Methyl Ethyl Ketone Peroxide Ron-Hsin Chang, Chi-Min Shu and Po-Yin Yeh...

159

Control of mercury methylation in wetlands through iron addition  

E-Print Network [OSTI]

Mason, R. P. ; Flegal, A. R. , Mercury speciation in the SanP. ; Flegal, A. R. , Decadal mercury trends in San FranciscoP. G. ; Nelson, D. C. , Mercury methylation from unexpected

Sedlak, David L; Ulrich, Patrick D

2009-01-01T23:59:59.000Z

160

Methyl arsenic adsorption and desorption behavior on iron oxides  

E-Print Network [OSTI]

METHYL ARSENIC ADSORPTION AND DESORPTION BEHAVIOR ON IRON OXIDES A Thesis by BRANDON JAMES LAFFERTY Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 2004 Major Subject: Soil Science METHYL ARSENIC ADSORPTION AND DESORPTION BEHAVIOR ON IRON OXIDES A Thesis by BRANDON JAMES LAFFERTY Submitted to Texas A&M University...

Lafferty, Brandon James

2005-08-29T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

The synthesis of some N-methylated aminoalkylphosphonic acids  

E-Print Network [OSTI]

(XLIII) were o heated with diethyl hydrogenphosphonate (XVI) at approximately 100 until the evolution of dimethylarnine (XXX) ceased. The 1-dimethyl- amino 1-alkenes (XLIV) reacted exothermically with diethyl hydro- genphosphonate (XVI) once... exothermically with methyl iodide at room temperature whereas the other eaters, which contained more bulky (R) substituents, did not. Secondly, the betaine obtained m the highest yield, N, N, N-trimethyl-N-(phosphono- methyl)ammonium hydroxide, mner salt...

Eikenberry, Jon Nathan

1966-01-01T23:59:59.000Z

162

Solvent Extraction Behavior of Neptunium (IV) Ions between Nitric Acid and Diluted 30% Tri-butyl Phosphate in the Presence of Simple Hydroxamic Acids  

SciTech Connect (OSTI)

Formo- and aceto-hydroxamic acids are very effective reagents for stripping tetravalent actinide ions such as Np(IV) and Pu(IV) ions from a tri-butyl phosphate phase into nitric acid. Distribution data for Np(IV) in the presence of these hydroxamate ions have now been accumulated and trends established. Stability constants for aceto-hydroxamate complexes of Np(IV) and Np(V) ions have also been determined in a perchlorate medium, and these reaffirm the affinity of hydroxamate ligands for actinide (IV) ions over actinyl (V,VI) ions.

Taylor, Robin J.; Sinkov, Sergey I.; Choppin, Gregory R.; May, Iain

2008-01-15T23:59:59.000Z

163

Health risks associated with exposure to gasoline additives-methyl tertiary butyl ether [MTBE]. Hearing before a Subcommittee of the Committee on Appropriations, United States Senate, One Hundred Third Congress, First Session, Special Hearing  

SciTech Connect (OSTI)

This hearing focuses on an Alaskan study by the Centers for Disease Control which examines possible health risks associated with exposure to gasoline additive know as MTBE. Testimony is given by Dr. William Roper, Director, CDC.

Not Available

1993-01-01T23:59:59.000Z

164

Derivation of a human equivalent concentration for n-butanol using a physiologically based pharmacokinetic model for n-butyl acetate and metabolites n-butanol and n-butyric acid  

SciTech Connect (OSTI)

The metabolic series (family) approach for risk assessment uses a dosimetry-based analysis to develop toxicity information for a group of metabolically linked compounds using pharmacokinetic (PK) data for each compound and toxicity data for the parent compound. An initial physiologically-based pharmacokinetic (PBPK) model was developed to support the implementation of the metabolic series approach for n-butyl acetate and its subsequent metabolites, n-butanol, and n-butyric acid (the butyl series) (Barton et al. 2000). In conjunction with pilot pharmacokinetic studies, the model was used to design the definitive intravenous (i.v.) PK studies. Rats were implanted with dual indwelling cannulae and administered test compounds by i.v. bolus dose, i.v. infusion, or by inhalation in a recirculating closed chamber. Hepatic, vascular and extravascular metabolic constants for metabolism were estimated by fitting the model to the blood time course data from these experiments. The respiratory bioavailability of n-butyl acetate and n-butanol was estimated from closed chamber inhalation studies and measured ventilation rates. The resulting butyl series PBPK model successfully reproduces the blood time course of these compounds following i.v. administration, and inhalation exposure to n-butyl acetate and n-butanol. A fully scaled human version of the model successfully reproduces arterial blood n-butanol kinetics following inhalation exposure to n-butanol. These validated i.v (rat) and inhalation route models (rat, butyl acetate, n-butanol; human, butanol only) can be used to support species and dose-route extrapolations required for risk assessment of butyl series family of compounds. Further, this work demonstrates the usefulness of i.v. kinetic data for parameterization of systemic metabolism and the value of collaboration between experimentalists and kineticists in the development of PBPK models. The product of this effort, validated rat and human PBPK models for the butyl series compounds, illustrates the effectiveness of broad multi-institutional public/private collaborations in the pursuit of developing state of the art tools for risk assessment.

Teeguarden, Justin G.; Deisinger, P. J.; Poet, Torka S.; English, J C.; Faber, W D.; Barton, H. A.; Corley, Rick A.; Clewell, III, H. J.

2005-05-01T23:59:59.000Z

165

Nested methylation-specific polymerase chain reaction cancer detection method  

DOE Patents [OSTI]

A molecular marker-based method for monitoring and detecting cancer in humans. Aberrant methylation of gene promoters is a marker for cancer risk in humans. A two-stage, or "nested" polymerase chain reaction method is disclosed for detecting methylated DNA sequences at sufficiently high levels of sensitivity to permit cancer screening in biological fluid samples, such as sputum, obtained non-invasively. The method is for detecting the aberrant methylation of the p16 gene, O 6-methylguanine-DNA methyltransferase gene, Death-associated protein kinase gene, RAS-associated family 1 gene, or other gene promoters. The method offers a potentially powerful approach to population-based screening for the detection of lung and other cancers.

Belinsky, Steven A. (Albuquerque, NM); Palmisano, William A. (Edgewood, NM)

2007-05-08T23:59:59.000Z

166

Methods for detection of methyl-CpG dinucleotides  

DOE Patents [OSTI]

The invention provides methods for enriching methyl-CpG sequences from a DNA sample. The method makes use of conversion of cytosine residues to uracil under conditions in which methyl-cytosine residues are preserved. Additional methods of the invention enable to preservation of the context of me-CpG dinucleotides. The invention also provides a recombinant, full length and substantially pure McrA protein (rMcrA) for binding and isolation of DNA fragments containing the sequence 5'-C.sup.MeCpGG-3'. Methods for making and using the rMcrA protein, and derivatives thereof are provided.

Dunn, John J.

2013-01-29T23:59:59.000Z

167

Methods for detection of methyl-CpG dinucleotides  

DOE Patents [OSTI]

The invention provides methods for enriching methyl-CpG sequences from a DNA sample. The method makes use of conversion of cytosine residues to uracil under conditions in which methyl-cytosine residues are preserved. Additional methods of the invention enable to preservation of the context of me-CpG dinucleotides. The invention also provides a recombinant, full length and substantially pure McrA protein (rMcrA) for binding and isolation of DNA fragments containing the sequence 5'-C.sup.MeCpGG-3'. Methods for making and using the rMcrA protein, and derivatives thereof are provided.

Dunn, John J

2013-11-26T23:59:59.000Z

168

Methods for detection of methyl-CpG dinucleotides  

DOE Patents [OSTI]

The invention provides methods for enriching methyl-CpG sequences from a DNA sample. The method makes use of conversion of cytosine residues to uracil under conditions in which methyl-cytosine residues are preserved. Additional methods of the invention enable to preservation of the context of me-CpG dinucleotides. The invention also provides a recombinant, full length and substantially pure McrA protein (rMcrA) for binding and isolation of DNA fragments containing the sequence 5'-C.sup.MeCpGG-3'. Methods for making and using the rMcrA protein, and derivatives thereof are provided.

Dunn, John J.

2012-09-11T23:59:59.000Z

169

Effects of hydration water on protein methyl group dynamics insolution  

SciTech Connect (OSTI)

Elastic and quasielastic neutron scattering experiments have been used to investigate the dynamics of methyl groups in a protein-model hydrophobic peptide in solution. The results suggest that, when the hydrophobic side chains are hydrated by a single hydration water layer, the only allowed motions are confined and attributed to librational and rotational movement associated with the methyl groups. They provide unique experimental evidence that the structural and dynamical properties of the interfacial water strongly influence the side-chain dynamics and the activation of diffusive motion.

Russo D; Hura GL; Copley JRD

2007-01-01T23:59:59.000Z

170

Freezing of Dynamics of a Methyl Group in a Protein Hydrophobic...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Freezing of Dynamics of a Methyl Group in a Protein Hydrophobic Core at Cryogenic Temperatures by Deuteron NMR Spectroscopy. Freezing of Dynamics of a Methyl Group in a Protein...

171

Environmental and age effects on methylation changes in human brain and blood cells  

E-Print Network [OSTI]

Previous studies have shown that DNA methylation may 1 e associated with disease, aging, the rate of aging and genetics. In this thesis, age is accurately predicted from DNA methylation in brain and blood tissues using two ...

Giguzinsky, Orit

2014-01-01T23:59:59.000Z

172

NIOSH Manual of Analytical Methods (third edition). Fourth supplement  

SciTech Connect (OSTI)

The NIOSH Manual of Analytical Methods, 3rd edition, was updated for the following chemicals: allyl-glycidyl-ether, 2-aminopyridine, aspartame, bromine, chlorine, n-butylamine, n-butyl-glycidyl-ether, carbon-dioxide, carbon-monoxide, chlorinated-camphene, chloroacetaldehyde, p-chlorophenol, crotonaldehyde, 1,1-dimethylhydrazine, dinitro-o-cresol, ethyl-acetate, ethyl-formate, ethylenimine, sodium-fluoride, hydrogen-fluoride, cryolite, sodium-hexafluoroaluminate, formic-acid, hexachlorobutadiene, hydrogen-cyanide, hydrogen-sulfide, isopropyl-acetate, isopropyl-ether, isopropyl-glycidyl-ether, lead, lead-oxide, maleic-anhydride, methyl-acetate, methyl-acrylate, methyl-tert-butyl ether, methyl-cellosolve-acetate, methylcyclohexanol, 4,4'-methylenedianiline, monomethylaniline, monomethylhydrazine, nitric-oxide, p-nitroaniline, phenyl-ether, phenyl-ether-biphenyl mixture, phenyl-glycidyl-ether, phenylhydrazine, phosphine, ronnel, sulfuryl-fluoride, talc, tributyl-phosphate, 1,1,2-trichloro-1,2,2-trifluoroethane, trimellitic-anhydride, triorthocresyl-phosphate, triphenyl-phosphate, and vinyl-acetate.

Not Available

1990-08-15T23:59:59.000Z

173

Ultrafast photochemistry of methyl hydroperoxide on ice particles  

E-Print Network [OSTI]

Ultrafast photochemistry of methyl hydroperoxide on ice particles M. A. Kambouresa , S. AOOH, on water clusters produces a surprisingly wide range of products on a subpicosecond time scale | photodissociation Photoinduced processes at surfaces of water or ice are of interest in atmospheric chemistry

Nizkorodov, Sergey

174

MTBE Production Economics (Released in the STEO April 2001)  

Reports and Publications (EIA)

The purpose of this analysis is to evaluate the causes of methyl tertiary butyl ether (MTBE) price increases in 2000.

2001-01-01T23:59:59.000Z

175

Phase 1 Methyl Iodide Deep-Bed Adsorption Tests  

SciTech Connect (OSTI)

Nuclear fission results in the production of fission products (FPs) and activation products including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent [Jubin 2012b]. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the first phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during Fiscal Year (FY) 2013 and early FY-2014. Testing has been performed to address questions posed in the test plan, and followed the testing outline in the test plan. Tests established detection limits, developed procedures for sample analysis with minimal analytical interferences, and confirmed earlier results that show that the methyl iodide reacts when in contact with the AgZ sorbent, and not significantly in the gas flow upstream of the sorbent. The reaction(s) enable separation of the iodine from the organic moiety, so that the iodine can chemisorb onto the sorbent. The organic moiety can form other compounds, some of which are organic compounds that are detected and can be tentatively identified using GC-FID and GCMS. Test results also show that other gas constituents (NOx and/or H2O) can affect the methyl iodide reactions. With NOx and H2O present in the gas stream, the majority of uncaptured iodine exiting iodine-laden sorbent beds is in the form of I2 or HI, species that are soluble in NaOH scrubbing solution for iodine analysis. But when NOx and H2O are not present, then the majority of the uncaptured iodine exiting iodine-laden sorbent is in the form of methyl iodide. Methyl iodide adsorption efficiencies have been high enough so that initial DFs exceed 1,000 to 10,000. The methyl iodide mass transfer zone depths are estimated at 4-8 inches, possibly deeper than mass transfer zone depths estimated for I2 adsorption on AgZ. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption under various conditions specified in the methyl iodide test plan, and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

Nick Soelberg; Tony Watson

2014-08-01T23:59:59.000Z

176

Modeling of the simultaneous extraction of nitric acid and uranyl nitrate with tri-n-butyl phosphate. Application to extraction operation  

SciTech Connect (OSTI)

A mathematical model developed for the equilibrium HNO{sub 3}-UO{sub 2}(NO{sub 3}){sub 2}-tri-n-butyl phosphate (TBP)-diluent is the basis of the computation of distribution isotherms. The isotherms are used to study the influence of TBP concentration on two chosen operation parameters, distribution coefficients and number of theoretical stages, for the selected flow sheets. It is established that an increase in TBP concentration leads to a decrease in the number of theoretical stages for the extraction flow sheets but to their increase for the striping flow sheets. Given diagrams can be used to determine the efficiency of extraction processes. Agreement with available literature calculations on the number of theoretical stages supports the use of the model in the computation of distribution isotherms, of the system quoted above, in a wide range of nitric acid, uranyl nitrate, and TBP concentrations.

Comor, J.J.; Tolic, A.S.; Kopecni, M.M.; Petkovic, D.M. [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia). Chemical Dynamics Lab.] [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia). Chemical Dynamics Lab.

1999-01-01T23:59:59.000Z

177

Arco chimie focuses on PA at FOS  

SciTech Connect (OSTI)

Arco Chimie France (Fos-sur-Mer), at a recent meeting at its southern France manufacturing site, emphasized that future strategy is strongly focused on its propylene oxide (PO) and derivatives activities. The F2.5 billion ($466 million)-Fe billion/year operation manufactures 200,000 m.t./year of PO, about 70% for captive use and the balance for the merchant market; 550,000 m.t./year of methyl tert butyl ether (MTBE); 97,000 m.t./year of polyols; and 70,000 m.t./year of propylene glycols. There has been talk of Arco modifying its Fos MTBE plant to make it flexible for ethyl tert-butyl ether (ETBE) output; the parent company already operates an MTBE/ETBE pilot unit at Corpus Christi, TX. But Arco Chimie notes there is insufficient bioethanol feedstock availability to convert all production to ETBE. The company would also require investment in new storage capacity for ethanol and ETBE. However, France's biofuels program is not yet clearly defined, and it is politically sensitive because it depends heavily on government subsidies offered to farmers. That, says Arco, makes it impossible to have an accurate idea of how much ethanol will be available.

Jackson, D.

1992-12-02T23:59:59.000Z

178

Fused ring and linking groups effect on overcharge protection for lithium-ion batteries.  

SciTech Connect (OSTI)

The derivatives of 1,3-benzodioxan (DBBD1) and 1,4-benzodioxan (DBBD2) bearing two tert-butyl groups have been synthesized as new redox shuttle additives for overcharge protection of lithium-ion batteries. Both compounds exhibit a reversible redox wave over 4 V vs Li/Li{sup +} with better solubility in a commercial electrolyte (1.2 M LiPF{sub 6}) dissolved in ethylene carbonate/ethyl methyl carbonate (EC/EMC 3/7) than the di-tert-butyl-substituted 1,4-dimethoxybenzene (DDB). The electrochemical stability of DBBD1 and DBBD2 was tested under charge/discharge cycles with 100% overcharge at each cycle in MCMB/LiFePO{sub 4} and Li{sub 4}Ti{sub 5}O{sub 12}/LiFePO{sub 4} cells. DBBD2 shows significantly better performance than DBBD1 for both cell chemistries. The structural difference and reaction energies for decomposition have been studied by density functional calculations.

Weng, W.; Zhang, Z.; Redfern, P. C.; Curtiss, L. A.; Amine, K.

2011-02-01T23:59:59.000Z

179

Mercury Methylation in Mine Wastes Collected from Abandoned Mercury Mines in the USA  

SciTech Connect (OSTI)

Mercury mines contain highly elevated Hg contents, but more problematic environmentally are elemental Hg and soluble Hg salts produced during ore retorting that remain in wastes at mine sites. Under certain conditions, these inorganic Hg compounds convert to bioavailable, highly toxic organic Hg forms. Speciation and transformation of Hg was studied in wastes collected from abandoned Hg mines at McDermitt, NV, and Terlingua, TX, which are moderate size on an international scale and produced about 10,000 and 5,000 t of elemental Hg, respectively. In waste samples, we measured total Hg and methyl-Hg contents, identified various Hg compounds using Hg-thermo-desorption pyrolysis, and determined rates of Hg methylation and methyl-Hg demethylation using isotopic-tracer methods. Pyrolysis analysis of mine wastes showed variable amounts of cinnabar, metacinnabar, Hg salts, elemental Hg, and elemental Hg sorbed onto particulates such as clay and Fe-oxides. Mine wastes with the highest methyl-Hg contents correspond to those with elemental Hg and particulate-sorbed elemental Hg, and also produced the highest laboratory-estimated potential Hg methylation rates, as much as 4.8%/day. Samples containing dominantly cinnabar showed little or no Hg methylation. Mine wastes with high methyl-Hg contents generally showed low methyl-Hg demethylation, suggesting that Hg methylation was dominant. Both mines are located in semiarid climates, and during this study, streambeds below the mines were dry. Total Hg contents in stream sediment collected below the mines show significant dilution, and methyl-Hg contents were typically below the limit of determination. Methylation of Hg downstream from Hg mines is probably lower in arid climates due to lack of mine-water runoff and lower microbial activity. The correspondence of mine wastes containing elemental Hg and high methyl-Hg contents suggests that Hg0 oxidizes to Hg2+, which is subsequently bioavailable for microbial Hg methylation.

Gray, John E. (U.S. Geological Survey); Hines, Mark E. (Massachusetts, Univ Of); Biester, Harald (Heidelberg College); Lasorsa, Brenda K. (BATTELLE (PACIFIC NW LAB))

2003-05-01T23:59:59.000Z

180

Metal catalyzed copolymerization processes involving carbon oxides as substrates  

E-Print Network [OSTI]

backbone and electron donating tert-butyl groups in the phenolate rings. This catalyst was used to investigate the effect of altering the nature of the cocatalyst and its concentration. The coupling of carbon monoxide and aziridines has been shown...

Phelps, Andrea Lee

2005-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Accelerated Luminophore Discovery through Combinatorial Michael S. Lowry, William R. Hudson, Robert A. Pascal, Jr., and Stefan Bernhard*  

E-Print Network [OSTI]

. There are three electrochemical stages associated with light emission in a diode-type device: (1) charge injection,4-di-tert-butyl-2,2-dipyridyl), marking the highest emission energy from a single-layer device, to date

Bernhard, Stefan

182

High-resolution infrared measurements on HSOH: Analysis of the OH fundamental vibrational mode  

E-Print Network [OSTI]

-wave spectroscopy on HSOH and H34 SOH [1]. The authors used flash vacuum pyrolysis of di-tert-butyl sulfoxide] identified five of six fundamental vibrational modes of matrix isolated HSOH formed by pyrolysis of di

Giesen, Thomas

183

Soluble hyperbranched grafts on polyethylene surfaces  

E-Print Network [OSTI]

Here we report two methods to synthesize hyperbranched poly(acrylic acid) grafts on polyethylene films and powders. The previously reported route using ?,[]-diaminopoly(tert-butyl acrylate) was repeated and all previous results were confirmed...

Britton, Danielle M

2002-01-01T23:59:59.000Z

184

Transport study of hafnium(IV) and zirconium(IV) ions mutual separation by using Tri-n-butyl phosphate-xylene-based supported liquid membranes  

SciTech Connect (OSTI)

A Hf transport study through supported liquid membranes has been carried out to determine flux and permeability data for this metal ion. Tri-n-butyl phosphate (TBP)-xylene-based liquid membranes supported in polypropylene hydrophobic microporous film have been used. These data for hafnium and the previous data for zirconium have furnished the Zr to Hf flux ratio (S) as a function of nitric acid and TBP concentrations of the order of 12 in a single stage at room temperature. Optimum conditions for the separation of these two metal ions appear to 5-6 TBP mol/dm{sup 3} HNO{sub 3}, concentrations {le} 2.93 mol/dm{sup 3}, and 10C. The value of S from an aqueous solution containing 2.4% Hf with respect to Zr has been found to be >125 at 10C and 1.78 mol/dm{sup 3} TBP concentration in the membrane. The technique appears to be feasible for purification of Zr respect to Hf or vice versa.

Chaudry, M.A.; Ahmed, B. (Pakistan Inst. of Nuclear Science and Technology, Islamabad (Pakistan))

1992-02-01T23:59:59.000Z

185

E-Print Network 3.0 - acibenzolar-s-methyl para controle Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

a coffee-leaf extract formulation in tomato Summary: ), acibenzolar-S-methyl (Bion) or water (control) and three days subsequently infected with the tomato pathogen... in the...

186

Durability of Poly (Methyl Methacrylate) Lenses Used in Concentrating Photovoltaics (Presentation)  

SciTech Connect (OSTI)

This presentation reports the findings of NREL's screen test to characterize the durability of poly (methyl methacrylate) lenses used in concentrated photovoltaics.

Miller, D.; Gedvilas, L.; To, B.; Kennedy, C.; Kurtz, S.

2010-10-21T23:59:59.000Z

187

E-Print Network 3.0 - anhydroecgonine methyl ester Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Idaho Collection: Environmental Sciences and Ecology 9 A Novel Post-translational Modification of Yeast Elongation Factor 1A Summary: that is released as volatile methyl groups...

188

7198 J. Org. Chem. 1995,60, 7198-7208 Gas Phase Decomposition of Conjugate Acid Ions of Simple  

E-Print Network [OSTI]

(MTBE),ethyl (ETBE),n-propyl,isopropyl,and isobutyl tert-butyl ethers have been examined experimentally spectroscopy (MIKES) experiments on deuterated ions from MTBE and ETBE. Mechanistic possibilities are probed tert-amyl ether and its deuterated analogues. Protonated MTBE displays a single unimolecular

Morton, Thomas Hellman

189

Characterization of the Deltaproteobacteria in contaminated and uncontaminated stream sediments and identification of potential mercury methylators  

SciTech Connect (OSTI)

Microbial communities were examined in surface stream sediments at 5 contaminated sites and 1 control site near Oak Ridge, TN, USA, to identify bacteria that could be contributing to mercury (Hg) methylation. The phylogenetic composition of the sediment bacterial community was examined over 3 quarterly sampling periods (36 samples) using 16S rRNA gene pyrosequencing. Only 3064 sequences (0.85% of the total community) were identified as Deltaproteobacteria, the only group known to methylate Hg, using the Ribosomal Database Project classifier at the 99% confidence threshold. Constrained ordination techniques indicated statistically significant positive linear correlations between Desulfobulbus spp., Desulfonema spp. and Desulfobacca spp. and methyl-Hg concentrations at the Hg-contaminated sites. In contrast, the distribution of organisms related to Byssovorax spp. was significantly correlated to inorganic carbon, nitrate and uranium concentrations but not to Hg or methyl-Hg. Overall, the abundance and richness of Deltaproteobacteria sequences were higher in uncontaminated sediments, while the majority of the members present at the contaminated sites were either known potential metal-reducers/methylators or metal tolerant species. Given the abundance relative to other known Hg methylators and the association with methyl-Hg, Desulfobulbus spp. is considered a prime candidate for involvement in Hg methylation in these streams.

Mosher, Jennifer [ORNL; Vishnivetskaya, Tatiana A [ORNL; Elias, Dwayne A [ORNL; Podar, Mircea [ORNL; Brooks, Scott C [ORNL; Brown, Steven D [ORNL; Brandt, Craig C [ORNL; Palumbo, Anthony Vito [ORNL

2012-01-01T23:59:59.000Z

190

Arsenic Methylation and Bladder Cancer Risk in CaseControl Studies in Argentina and the  

E-Print Network [OSTI]

Arsenic Methylation and Bladder Cancer Risk in Case­Control Studies in Argentina and the United's susceptibility to bladder cancer. Methods: Urinary methylation products were measured in subjects from Argentina (114 cases and 114 controls) and the United States (23 cases and 49 controls). Results: In Argentina

California at Berkeley, University of

191

et al. (2008) identified several additional methylation sites on FOXO1 that ap-  

E-Print Network [OSTI]

, it remains to be deter- mined how methylation alters the activity and posttranslational regulation. In this light, methylation could, therefore, play a very general role in the regulation of FOXO1 activity serve as a link between aging and age-related diseases such as diabe- tes and cancer. FOXO dysregulation

Hertel, Klemens J.

192

Mercury methylation in oxygen deficient zones of the oceans: No evidence for the predominance of anaerobes  

E-Print Network [OSTI]

Mercury methylation in oxygen deficient zones of the oceans: No evidence for the predominance Keywords: Methylmercury Oxygen minimum zone Arabian Sea Equatorial Eastern Pacific Mercury methylation Although a large fraction of the world's population is exposed to mercury through consumption of marine

Morel, François M. M.

193

Is Embolization of the Pancreas Safe? Pancreatic Histological Changes after Selective Transcatheter Arterial Embolization with N-Butyl Cyanoacrylate in a Swine Model  

SciTech Connect (OSTI)

Purpose: This study was designed to evaluate the safety of selective transcatheter arterial embolization (TAE) with N-butyl cyanoacrylate (NBCA) in a swine model in terms of histological changes in the pancreas. Methods: Three groups of two female swine (58-64 kg) per group underwent TAE of the dorsal pancreatic artery, under anesthesia, with 1:1, 1:4, and 1:9 mixtures of NBCA and iodized oil. Blood parameters were evaluated at days 1, 4, and 10 after TAE, after which the animals were sacrificed and pancreatic tissues were examined under light microscopy. Results: All of the animals were asymptomatic and survived for 10 days. Cone beam computed tomographic angiography revealed occlusion of the dorsal pancreatic artery and no enhancement in the embolized area. The white blood cell count and C-reactive protein level were elevated slightly on day 1 after TAE (mean {+-} SD: 252.7 {+-} 27.8 Multiplication-Sign 10{sup 2}/{mu}l and 0.15 {+-} 0.07 mg/l, respectively), but they normalized or remained near the upper normal limit thereafter. The serum amylase and lipase levels also were elevated on day 1 (8831.7 {+-} 2169.2 U/l and 130 {+-} 53.4 U/l, respectively) but normalized thereafter. Histologically, necrosis and fibrosis were noted only in the embolized segment, and necrosis and acute inflammatory reactions were absent in the nonembolized segment. The border between both segments was well defined. Lymphocytic infiltration and foreign body reaction were noted around the embolized vessels. Conclusions: Selective TAE with NBCA in the pancreas caused localized ischemic necrosis without clinically significant pancreatitis; therefore, this procedure is tolerable in swine.

Okada, Takuya, E-mail: okabone@gmail.com; Yamaguchi, Masato [Kobe University Graduate School of Medicine, Department of Radiology (Japan); Takahashi, Takuya [Kobe Red Cross Hospital, Department of Pathology (Japan); Izaki, Kenta; Uotani, Kensuke; Sakamoto, Noriaki; Sugimura, Kazuro; Sugimoto, Koji [Kobe University Graduate School of Medicine, Department of Radiology (Japan)

2012-02-15T23:59:59.000Z

194

MTBE still in poor health, despite the Clean Air Act  

SciTech Connect (OSTI)

After the second winter oxygenated fuels program of the 1990 Clean Air Act, producers of methyl tert-butyl ether (MTBE) are still feeling the chill of poor profitability. Despite the strong demand growth for MTBE to meet oxygen requirements in reformulated gasoline (RFG), oversupply still dogs the market. That, combined with a run-up in feedstock prices, has seen margins for MTBE markers all but evaporate. And it seems matters are likely to get worse before they get better. This week, Belvieu Environmental Fuels (BEF; Houston) expects to startup its 15,000-bbl/day MTBE plant at Mont Belvieu, TX. In late July, Texaco will start up its 15,000-bbl/day MTBE/propylene oxide (PO) plant at Port Neches, TX. In addition, a rash of refinery-based MTBE and tert-amyl methyl ether projects are nearing completion. {open_quotes}Profitability in MTBE has been extremely poor,{close_quotes} says Marvin O. Schlanger, president of Arco Chemical Americas, the largest MTBE producer. There has, however, been some recent recovery on the spot market, with MTBE moving from less than 60 cts/gal to near cash-cost levels of 70 cts/gal. But contract prices remain depressed, and strength in butane and methanol pricing have all buy wiped out any gains in MTBE.

Wood, A.

1994-05-25T23:59:59.000Z

195

Methyl-CpG island-associated genome signature tags  

DOE Patents [OSTI]

Disclosed is a method for analyzing the organismic complexity of a sample through analysis of the nucleic acid in the sample. In the disclosed method, through a series of steps, including digestion with a type II restriction enzyme, ligation of capture adapters and linkers and digestion with a type IIS restriction enzyme, genome signature tags are produced. The sequences of a statistically significant number of the signature tags are determined and the sequences are used to identify and quantify the organisms in the sample. Various embodiments of the invention described herein include methods for using single point genome signature tags to analyze the related families present in a sample, methods for analyzing sequences associated with hyper- and hypo-methylated CpG islands, methods for visualizing organismic complexity change in a sampling location over time and methods for generating the genome signature tag profile of a sample of fragmented DNA.

Dunn, John J

2014-05-20T23:59:59.000Z

196

THE JOURNAL OF CHEMICAL PHYSICS 138, 054301 (2013) Photodissociation dynamics of the methyl perthiyl radical at 248 nm  

E-Print Network [OSTI]

the photodissociation of the methyl perthiyl radical CH3SS at 248 nm. The radical was produced by flash pyrolysis

Neumark, Daniel M.

197

Optical measurements of methyl group tunneling in molecular crystals: Temperature dependence of the nuclear spin conversion rate  

E-Print Network [OSTI]

) The tunneling methyl groups in dimethyl-s-tetrazine (DMST) doped single crystals of durene were investigated

198

Modelling Study of the Low-Temperature Oxidation of Large Methyl Esters J. Biet, V. Warth, O. Herbinet*  

E-Print Network [OSTI]

-decane / methyl palmitate mixture in a jet-stirred reactor. This paper also presents the construction and a comparison of models for methyl esters from C7 up to C17 in terms of conversion in a jet-stirred reactor, the development of renewable energy is more vital than ever [1,2]. The production of biofuels such as methyl

Paris-Sud XI, Université de

199

energy savings by the use of mtbe to replace alkylate in automotive gasolines  

SciTech Connect (OSTI)

This paper presents data on the differences in energy consumption in the production of leaded and unleaded AI-93 gasolines with various blend components. The authors investigate as high-octane components certain products that are more effective in use and less energy-consuming in production in comparison with alkylate. In particular, methyl tert-butyl ether (MTBE) is discussed; it is not poisonous, it has a high heat of combustion, and it does not attack materials of construction. The addition of 11% MTBE to gasoline lowers the cold start temperature of engines by 10-12 degrees. Moreover, no adjustment of the carburetor is required for the changeover to gasoline with 11% MTBE.

Englin, B.A.; Emel'yanov, V.E.; Terent'ev, G.A.; Vinogradov, A.M.

1986-07-01T23:59:59.000Z

200

Removal of MTBE and other organic contaminants from water by sorption to high silica zeolites  

SciTech Connect (OSTI)

Select zeolites with high SiO{sub 2}/Al{sub 2}O{sub 3} ratios were shown to effectively remove methyl tert-butyl ether (MTBE), chloroform, and trichloroethylene (TCE) from water. In laboratory studies using batch sorption equilibria, high Si large-port mordenite and ZSM-5 (silicalite) were found to have sorption properties for MTBE and TCE superior to activated carbon. for example, at an equilibrium solution concentration of 100 {micro}g/L, high Si mordenite retained 8--12x more MTBE than either of two powdered activated carbons used as reference sorbents. Sorption results also highlight the importance of pore size and SiO{sub 2}/Al{sub 2}O{sub 3} ration on contaminant removal efficiencies by zeolites.

Anderson, M.A.

2000-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

APPLICATIONS OF LAYERED DOUBLE HYDROXIDES IN REMOVING OXYANIONS FROM OIL REFINING AND COAL MINING WASTEWATER  

SciTech Connect (OSTI)

Western Research Institute (WRI), in conjunction with the U.S. Department of Energy (DOE), conducted a study of using the layered double hydroxides (LDH) as filter material to remove microorganisms, large biological molecules, certain anions and toxic oxyanions from various waste streams, including wastewater from refineries. Results demonstrate that LDH has a high adsorbing capability to those compounds with negative surface charge. Constituents studied include model bacteria, viruses, arsenic, selenium, vanadium, diesel range hydrocarbons, methyl tert-butyl ether (MTBE), mixed petroleum constituents, humic materials and anions. This project also attempted to modify the physical structure of LDH for the application as a filtration material. Flow characterizations of the modified LDH materials were also investigated. Results to date indicate that LDH is a cost-effective new material to be used for wastewater treatment, especially for the treatment of anions and oxyanions.

Song Jin; Paul Fallgren

2006-03-01T23:59:59.000Z

202

Coadsorption of methanol and isobutene on HY zeolite  

SciTech Connect (OSTI)

In order to develop a better understanding of methyl tert-butyl ether (MTBE) synthesis on zeolites, the coadsorption of methanol and isobutene on HY zeolite was investigated using IR spectroscopy. Initial adsorption of isobutene alone at 35{degree}C led to rapid oligomerization yielding strongly bound oligomers. The subsequent coadsorption of methanol did not induce any changes in the zeolite-adsorbate complexes. TPD following the coadsorption showed that the Bronsted acid sites could be restored by temperature treatment above approximately 300{degree}C. When methanol was adsorbed first and isobutene was subsequently coadsorbed, MTBE was formed even at 35{degree}C on the catalyst surface. MTBE desorbed easily at a temperature of 70{degree}C, restoring a major fraction of the Bronsted acid sites. Methanol was concluded to decrease the probability of oligomerization by effectively competing for the acid sites. 34 refs., 6 figs.

Kogelbauer, A.; Goodwin, J.G. Jr. [Univ. of Pittsburgh, PA (United States); Lercher, J.A. [Univ. of Twente, Enschede (Netherlands)

1995-05-25T23:59:59.000Z

203

Autoignition behavior of lean mixtures: Chemical and thermodynamics effects  

SciTech Connect (OSTI)

Knock characteristics of natural gas (NG), 89 octane unleaded gasoline, 2,2-dimethyl butane (22DMB), and methyl tert-butyl ether (MTBE) in stoichiometric and lean fuel-air mixtures were studied in a production 4-cylinder automotive engine. The Intake Temperature at the Knock Limit (ITKL) was different for each fuel but always higher in lean mixtures. Gasoline and 22DMB exhibited much greater increases in ITKL than MTBE and NG at lean conditions. Surprisingly, for lean mixtures 22DMB exhibited higher ITKL than MTBE and was almost as high as NG. Comparison with detailed numerical modelling was very favorable. Computations show that both differences in chemistry and end-gas temperature and pressure histories are responsible for these trends. This behavior is interpreted in terms of the Negative Temperature Coefficient behavior of hydrocarbon oxidation. The implication of these results for the specification of optimal fuels for lean-burn engine is discussed.

Ronney, P.D.; Shoda, M.; Waida, S.T. [Princeton Univ., NJ (United States). Dept. of Mechanical and Aerospace Engineering; Westbrook, C.K.; Pitz, W.J. [Lawrence Livermore National Lab., CA (United States)

1992-01-15T23:59:59.000Z

204

Korean oxygenates rule sparks MTBE capacity plans  

SciTech Connect (OSTI)

The Korean government`s strict standard for gasoline sold domestically is expected to have a significant impact on the methyl tert-butyl ether (MTBE) market. The mandate-requiring gasoline oxygen content of 0.5% this year, 0.75% by 1996, and 1.0% by 1998-has sparked a rush by Korean refineries to build new MTBE plants. If expansion plans are carried out, Korea`s MTBE capacity will increase from 280,000 m.t./year to 650,000 m.t./year by 1996, far surpassing predicted demand. Honam Oil, part of the Lucky Group, plans startup of a 100,000-m.t./year unit at Yeochon by early 1996. In addition, by the end of 1996 Ssangyong Oil will bring a 100,000-m.t./year unit onstream.

Kim, Hyung-Jin

1994-06-15T23:59:59.000Z

205

Ecofuel plans MTBE plant in Italy  

SciTech Connect (OSTI)

Ecofuel (Milan), an ENI company, is evaluating construction of a new methyl tert-butyl ether (MTBE) plant in Italy, but has shelved plans for a world-scale MTBE unit in Mexico. The Italian unit is tied to ethylene expansion now under way. Later this year EniChem (Milan), a sister company, is due to complete construction of a 360,000-m.t./year cracker at Brindisi. The C{sub 4} stream available there and from the existing cracker at Priolo in Sicily should provide enough feed for a unit of up to 100,000 m.t./year of MTBE capacity. Some of the feedstock could also come from the Ravenna cracker.

Alperowicz, N.

1992-04-29T23:59:59.000Z

206

Proton NMR analysis of octane number for motor gasoline: Part V  

SciTech Connect (OSTI)

A method to predict the octane number of automobile gasoline containing methyl tert-butyl ether (MTBE) by proton magnetic resonance (PMR) spectrometry was studied. Samples of gasoline whose octane numbers had been identified according to the ASTM standards (commercially available premium gasoline to which MTBE was added at rates of 7 vol % and 14 vol %) were used in this investigation of the effect of MTBE on the octane number. The findings were utilized to introduce a term regarding MTBE into the previously reported linear regression equation for estimating the octane number from the PMR spectrum, and the appropriateness of the linear regression equation was assessed. As a result the MTBE contents in the sample were determined with satisfactory accuracy by using a standard addition method, and a linear regression equation reflecting the effect of MTBE was obtained. These achievements are reported. 11 refs., 3 figs., 5 tabs.

Ichikawa, M.; Nonaka, N.; Amano, H.; Takada, I.; Ishimori, S. [Suzuki Motor Corp., Hamamatsu (Japan); Andoh, H.; Kumamoto, K. [Showa Shell Sikiyu Tokyo (Japan)

1992-10-01T23:59:59.000Z

207

A screening model for evaluating the degradation and transport of MTBE and other fuel oxygenates in the subsurface  

SciTech Connect (OSTI)

Methyl tert-butyl ether (MTBE) has received high attention as it contributed to cleaner air and contaminated thousands of underground storage tank sites. Because MTBE is very water soluble, it is more difficult to remove from water by conventional remediation techniques. Therefore, biodegradation of MTBE has become a remediation alternative. In order to understand the transport and transformation processes, they present a closed form solution as a screening tool in this paper. The possible reaction pathways of first-order reactions are described as a reaction matrix. The singular value decomposition is conducted analytically to decouple the partial differential equations of the multi-species transport system coupled by the reaction matrix into multiple independent subsystems. Therefore, the complexity of mathematical description for the reactive transport system is significantly reduced and analytical solutions may be previously available or easily derived.

Sun, Y; Lu, X

2004-04-20T23:59:59.000Z

208

MTBE, ethanol rules come under fire  

SciTech Connect (OSTI)

EPA is facing stiff challenges to the mandates for methyl tert-butyl ether (MTBE) and ethanol in its reformulated gasoline (RFG) program. Wisconsin officials are receiving hundreds of complaints about the alleged health effects and other problems with MTBE added to gasoline, and Gov. Tommy Thompson is demanding that EPA suspend the RFG program until April 1. Rep. James Sensenbrenner (R., WI) is threatening to introduce a bill to repeal the program in Wisconsin if EPA does not comply. However, EPA administrator Carol Browner says the agency will {open_quotes}defer any decision{close_quotes} on the request. EPA has sent technical experts to Milwaukee to respond to and monitor citizens` complaints.

Begley, R.

1995-03-01T23:59:59.000Z

209

Ecological hazards of MTBE exposure: A research agenda  

SciTech Connect (OSTI)

Fuel oxygenates are used in metropolitan areas across the United States in order to reduce the amount of carbon monoxide released into the atmosphere during the winter. The most commonly used fuel oxygenate is Methyl tert-butyl ether (MTBE). Its widespread use has resulted in releases into the environment. To date there has been only minimal effort to investigate ecological impacts caused by exposure to concentrations of MTBE typically found in environmental media. Research into the potential for MTBE to adversely affect ecological receptors is essential. Acquisition of such baselines data is especially critical in light of continuing inputs and potential accumulation of MTBE in environmental media. A research Agenda is included in this report and addresses: Assessing Ecological Impacts, Potential Ecological Impacts of MTBE (aquatic organisms, terrestrial organisms), Potential Ecological Endpoints, and A Summary of Research Needs.

Carlsen, T.; Hall, L.; Rice, D.

1997-03-01T23:59:59.000Z

210

Gas phase synthesis of MTBE on triflic-acid-modified zeolites  

SciTech Connect (OSTI)

The gas phase synthesis of MTBE (methyl tert-butyl ether) was studied using three series of triflic acid (TFA)-modified zeolites, the parent materials being HY, H-mordenite, and HZSM-5. Impregnation with TFA was found to enhance MTBE synthesis activity only for the large-pore zeolite Y and only up to a certain extent of modification. A high level of TFA modification caused a reduction in activity, apparently due to blockage of the active sites by TFA molecules and extra-lattice Al formed during the modification process. The mechanism of activity enhancement by TFA modification appears to be related to the formation of extra-lattice Al rather than the direct presence of TFA. 20 refs., 6 figs., 1 tab.

Nikolopoulos, A.A.; Kogelbauer, A.; Goodwin, J.G. Jr. [Univ. of Pittsburgh, PA (United States)] [and others] [Univ. of Pittsburgh, PA (United States); and others

1996-01-01T23:59:59.000Z

211

Lyondell`s new isobutylene route could fuel an MTBE capacity boost  

SciTech Connect (OSTI)

Driven by the hot growth prospects for methyl tert-butyl ether (MTBE), Lyondell Petrochemical (Houston) has developed a route to isobutylene it claims can produce the MTBE feedstock at half the capital cost of alternative synthesis technology. If proved, the process will be used in a new 7500-10,000 bbl/day MTBE plant at Channelview, TX. Lyondell also hopes to license the technology. {open_quotes}With expanding MTBE capacity, we will have to have new routes to isobutylene,{close_quotes} says Bob G. Gower, president and CEO of Lyondell. {open_quotes}We think this is a good fit within Lyondell, but also that it is important technology.{close_quotes} Gower declines to detail its specifics, but says it is a one-step isomerization of n-butenes to isobutylene. The firm has tested the process at a pilot unit and plans a demonstration unit in 1992.

Rotman, D.; Wood, A.

1992-03-25T23:59:59.000Z

212

Photocatalytic reactions of oxygenates on tropospheric oxide particles  

SciTech Connect (OSTI)

Oxygenates such as ethanol and tert-butyl methyl ether (MTBE) are finding increased use as additives to fuels. The relative merits of ethanol and MTBE have become the focus of intense debate with their ultimate fate as fugitive emissions representing one aspect of this controversy. Both species are known to react homogeneously with photogenerated OH radicals. Here we show that both can also photoreact on suspended solid particulates in the atmosphere with rates comparable to those of OH reactions. Heterogeneous reactions of ethanol yield acetaldehyde and those of MTBE give isobutene and formaldehyde (carcinogenic). Experiments by spectroscopic and kinetic techniques show that the active phases in fly ash are Fe and Ti oxides. In addition, the effects of humidity and alkali addition on the activity and selectivity of these reactions are also discussed. This work appears to be the first demonstration that volatile organic compounds can react as fast by a heterogeneous mechanism as by a homogeneous one in the atmosphere.

Idriss, H.; Seebauer, E.G.; Miller, A. [Univ. of Illinois, Urbana, IL (United States)

1996-10-01T23:59:59.000Z

213

Snamprogetti signs MTBE contracts  

SciTech Connect (OSTI)

Snamprogetti (Milan) will use a Russian-developed dehydrogenation process in a world-scale methyl tert-butyl ether (MTBE) plant it is to build at Arzew, Algeria for a previously announced joint venture of Sonatrach (Algiers), Total (Paris), and Ecofuel (Milan). The 600,000-m.t./year plant will be the first in the West to use the improved Snamprogetti-Yarsintez fluidized-bed dehydrogenation (FBD) technology proven on a demonstration plant at Yaroslavl, Russia. The process has also been selected for use in Oxyfuel Corp.`s 500,000-m.t./year MTBE plant near Beaumont, TX. Although the environmental permit is already in place, final agreement for this project has not yet been signed.

Alperowicz, N.

1992-04-15T23:59:59.000Z

214

EPA proposal sets MTBE back  

SciTech Connect (OSTI)

Methyl tert-butyl ether (MTBE) producers were looking for a boost from the official New Year`s start of EPA`s reformulated gasoline (RFG) program. But that prospect has been dimmed by an EPA-proposal-in reaction to concerns about RFG prices-to allow states to withdraw from the program. The states that have opted to out make up 5%-6% of the total RFG pool says Arthur Zadronzy, director/government outreach for MTBE producer Arco Chemical. {open_quotes}This is not a major hit, but it is one we have felt,{close_quotes} he says. Despite the state and EPA actions, MTBE producers are not worried about long-term consequences.

Lucas, A.

1995-01-04T23:59:59.000Z

215

Vapor-liquid equilibria of hydrocarbons and fuel oxygenates. 2  

SciTech Connect (OSTI)

Vapor-liquid equilibrium data for methyl tert-butyl ether (MTBE) + 1-heptene, MTBE + four-component gasoline prototype, ethanol + four-component gasoline prototype, and separately MTBE and ethanol with the Auto/Oil Air Quality Improvement Research Gasoline Blend A are reported. Small additions of MTBE have a very small effect on the total equilibrium pressure of this gasoline blend, and at most temperatures will decrease this pressure. In contrast, small additions of ethanol to this gasoline blend result in a significant increase in the equilibrium pressure at all temperatures. Analysis shows that the vapor-liquid equilibrium data for the MTBE-containing systems are easily correlated using a modified Peng-Robinson equation of state with conventional van der Waals one-fluid mixing rules. Data for mixtures containing ethanol cannot be accurately correlated in this way.

Bennett, A.; Lamm, S.; Orbey, H.; Sandler, S.I. (Univ. of Delaware, Newark (United States))

1993-04-01T23:59:59.000Z

216

High temperature concrete composites containing organosiloxane crosslinked copolymers  

DOE Patents [OSTI]

This invention relates to high temperature polymer concrete composites comprising about 10-30% by weight of a liquid monomer mixture consisting essentially of an organosiloxane polymer crosslinked with an olefinically unsaturated monomer selected from the group consisting of styrene, methyl methacrylate, trimethylolpropane trimethacrylate, triallyl cyanurate, n-phenylmalimide, divinyl benzene and mixtures theroef; and about 70-90% by weight of an inert inorganic filler system containing silica sand and preferably a member selected from the group consisting of portland cement, Fe.sub.2 O.sub.3, carbon black and mixtures thereof; and optionally a free radical initiator such as di-tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide and other organic peroxides to initiate crosspolymerization of the monomer mixture in the presence of the inorganic filler.

Zeldin, Arkady (Rego Park, NY); Carciello, Neal (Patchogue, NY); Kukacka, Lawrence (Port Jefferson, NY); Fontana, Jack (Shoreham, NY)

1980-01-01T23:59:59.000Z

217

Iran plans huge private sector MTBE plant  

SciTech Connect (OSTI)

An export-oriented 1-million m.t./year methyl tert-butyl ether (MTBE) plant is planned as one of Iran`s private sector investment projects. State-owned National Petrochemical Co (NPC; Tehran) and the Dubai-based Iranian businessman Abdul Wahab Galadari have signed a letter of intent allowing Galadari to develop the venture. Colt Engineering (Calgary, AL) is assisting Galadari with costs, planning and technology selection for the estimated $300-million plus venture. An important meeting with NPC is scheduled end of this month, says Galadari, and a financial package should be put together by end of March or April. The facility will most likely be wholly-owned by the Galadari family, roughly 50% by members resident in Iran and the remainder by the Dubai-based concern A.W. Galadari Sons. NPC says it may take a token shareholding in the venture.

Alperowicz, N.

1992-01-15T23:59:59.000Z

218

Self-ignition of S.I. engine model fuels: A shock tube investigation at high pressure  

SciTech Connect (OSTI)

The self-ignition of several spark-ignition (SI) engine fuels (iso-octane, methanol, methyl tert-butyl ether and three different mixtures of iso-octane and n-heptane), mixed with air, was investigated experimentally under relevant engine conditions by the shock tube technique. Typical modes of the self-ignition process were registered cinematographically. For temperatures relevant to piston engine combustion, the self-ignition process always starts as an inhomogeneous, deflagrative mild ignition. This instant is defined by the ignition delay time, {tau}{sub defl}. The deflagration process in most cases is followed by a secondary explosion (DDT). This transition defines a second ignition delay time, {tau}{sub DDT}, which is a suitable approximation for the chemical ignition delay time, if the change of the thermodynamic conditions of the unburned test gas due to deflagration is taken into account. For iso-octane at p = 40 bar, a NTC (negative temperature coefficient), behavior connected with a two step (cool flame) self-ignition at low temperatures was observed. This process was very pronounced for rich and less pronounced for stoichiometric mixtures. The results of the {tau}{sub DDT} delays of the stoichiometric mixtures were shortened by the primary deflagration process in the temperature range between 800 and 1,000 K. Various mixtures of iso-octane and n-heptane were investigated. The results show a strong influence of the n-heptane fraction in the mixture, both on the ignition delay time and on the mode of self-ignition. The self-ignition of methanol and MTBE (methyl tert-butyl ether) is characterized by a very pronounced initial deflagration. For temperatures below 900 K (methanol: 800 K), no secondary explosion occurs. Taking into account the pressure increase due to deflagration, the measured delays {tau}{sub DDT} of the secondary explosion are shortened by up to one order of magnitude.

Fieweger, K.; Blumenthal, R.; Adomeit, G. [RWTH, Aachen (Germany). Inst. fuer Allegemeine Mechanik] [RWTH, Aachen (Germany). Inst. fuer Allegemeine Mechanik

1997-06-01T23:59:59.000Z

219

Composition of the wax fraction of bitumen from methylated brown coals  

SciTech Connect (OSTI)

Changes in the group and individual compositions of the wax fractions of bitumen in the course of brown coal methylation were studied. With the use of IR and NMR spectroscopy and chromatography-mass spectrometry, it was found that the esters of methylated coal waxes consisted of the native esters of fatty acids and the methyl esters of these acids formed as a result of an alkylation treatment. Esterification and transesterification were predominant among the reactions of aliphatic fraction components. A positive effect of methanol alkylation on an increase in the yield of the aliphatic fractions was found.

S.I. Zherebtsov; A.I. Moiseev [Russian Academy of Sciences, Kemerovo (Russian Federation). Institute of Coal and Coal Chemistry

2009-04-15T23:59:59.000Z

220

Genomic DNA methylation in various developmental stages of two plant pathogenic fungi  

E-Print Network [OSTI]

blotting procedure. The blots were then hybridized with DNA probes from the highly repeated Neurospora crassa rDNA repeat unit labeled with [a. P] dCTP in a random-primed oligolabeling reaction. Results of the hybridizations were visualized... shows s. high degree of methylation at the inner (3') C in both stages (mycelia and sclerotia) at the genomic level. The rRNA genes exhibit the same high level of methylation at the 3' C with the addition of some stage specific methylation...

Schliesing, Laura Jo

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Anti-inflammatory and antifibrotic effects of methyl palmitate  

SciTech Connect (OSTI)

Methyl palmitate (MP) has been shown earlier to inhibit Kupffer cells and rat peritoneal macrophages. To evaluate the potential of MP to inhibit the activation of other macrophages, RAW cells (macrophages of alveolar origin) were treated with varying concentrations of MP (0.25, 0.5, 1 mM). Assessment of cytotoxicity using MTT assay revealed that 0.25 and 0.5 mM are not toxic to RAW cells. MP was able to inhibit the phagocytic function of RAW cells. Treatment of cells with MP 24 hours prior to LPS stimulation significantly decreased nitric oxide release and altered the pattern of cytokines release; there was a significant decrease in TNF-{alpha} and a significant increase in IL-10 compared to the controls. However, there is a non-significant change in IL-6 level. Furthermore, phosphorylation of inhibitory kappa B (I{kappa}B{alpha}) protein was significantly decreased in RAW cells treated with 0.5 mM MP after LPS stimulation. Based upon the in-vitro results, it was examined whether MP treatment will be effective in preventing bleomycin-induced lung inflammation and fibrosis in-vivo. Bleomycin given by itself caused destruction of the lung architecture characterized by pulmonary fibrosis with collapse of air alveoli and emphysematous. Bleomycin induced a significant increase in hydroxyproline level and activated NF-{kappa}B, p65 expression in the lung. MP co-treatment significantly ameliorated bleomycin effects. These results suggest that MP has a potential of inhibiting macrophages in general. The present study demonstrated for the first time that MP has anti-inflammatory and antifibrotic effect that could be through NF-kB inhibition. Thus MP like molecule could be a promising anti-inflammatory and antifibrotic drug. - Research Highlights: >Methyl palmitate is a universal macrophage inhibitor. >It could be a promising nucleus of anti-inflammatory and antifibrotic drugs. >The underlying mechanism of these effects could be through NF-kB inhibition.

El-Demerdash, Ebtehal, E-mail: ebtehal_dm@yahoo.com

2011-08-01T23:59:59.000Z

222

The Scientific Basis for the Regulation of Nanoparticles: Challenging Paracelsus and Pare  

E-Print Network [OSTI]

NANOTECHNOILOGY 402 (2007). 20. MTBE unquestionably causesTertiary-Butyl Ether (MTBE)-a Gasoline Additive-CausesMethyl Tertiary-butyl Ether (MTBE) in CD-I Mice and F-344

Goldstein, Bernard D.

2010-01-01T23:59:59.000Z

223

Bioremediation of the organophosphate methyl parathion using genetically engineered and native organisms  

E-Print Network [OSTI]

to remediate hazardous substances at significantly higher rates than found with natural systems. Specifically, degradation of methyl parathion (MP) by hydrolysis with a genetically engineered Escherichia coli was investigated along with degradation of one...

Diaz Casas, Adriana Z.

2005-11-01T23:59:59.000Z

224

Thermomechanical properties of polyhedral oligomeric silsequioxane- poly(methyl methacrylate) nanocomposites  

E-Print Network [OSTI]

Poly(methyl methacrylate)s (PMMA) containing polyhedral oligomeric silsesquioxane (POSS) nanoparticles (d [approx.] 1.5 nm) were subjected to heological, mechanical, and morphological tests to determine the effects that ...

Kopesky, Edward Thomas

2005-01-01T23:59:59.000Z

225

A unique regulatory phase of DNA methylation in the early mammalian embryo  

E-Print Network [OSTI]

DNA methylation is highly dynamic during mammalian embryogenesis. It is broadly accepted that the paternal genome is actively depleted of 5-methylcytosine at fertilization, followed by passive loss that reaches a minimum ...

Chan, Michelle M.

226

Halogenated 1'-methyl-1,2'-bipyrroles (MBPs) in the Norwestern Atlantic  

E-Print Network [OSTI]

Halogenated 1'-methyl-1,2'-bipyrroles (MBPs) are a distinctive class of marine organic compounds. They are naturally produced, they have a unique carbon structure, they are highly halogenated, and they bioaccumulate in ...

Pangallo, Kristin C

2009-01-01T23:59:59.000Z

227

Temporal and spatial variation in methyl bromide emissions from a salt marsh   

E-Print Network [OSTI]

Methyl bromide (CH3Br) is a trace gas involved in stratospheric ozone depletion with both anthropogenic and natural sources. Estimates of natural source strengths are highly uncertain. In this study, >320 highly temporally ...

Drewer, Julia; Heal, Mathew R; Heal, Kate V; Smith, Keith A

2006-01-01T23:59:59.000Z

228

Chromosome-wide mapping of DNA methylation patterns in normal and malignant prostate cells reveals pervasive methylation of gene-associated and conserved intergenic sequences  

E-Print Network [OSTI]

G island [13-15], chromosome-wide [15], or genome-wide [16] til- ing microarrays or to analyze by next generation sequen- cing [17,18]. Here, we describe the use of an MBD-chip approach (Figure 1A) to compare the chromosome-wide DNA methylation patterns... identified as differentially methylated in the LNCaP cells compared to the PrEC cells. We could then compare the distribution of CpG dinucleotide content and number of regions overlapping CpG islands in these simulated data sets with these parameters in our...

Yegnasubramanian, Srinivasan; Wu, Zhijin; Haffner, Michael C; Esopi, David; Aryee, Martin J; Badrinath, Raghav; He, Tony L; Morgan, James D; Carvalho, Benilton S; Zheng, Qizhi; De Marzo, Angelo M; Irizarry, Rafael A; Nelson, William G

2011-06-13T23:59:59.000Z

229

Radio-methyl vorozole and methods for making and using the same  

DOE Patents [OSTI]

Radiotracer vorozole compounds for in vivo and in vitro assaying, studying and imaging cytochrome P450 aromatase enzymes in humans, animals, and tissues and methods for making and using the same are provided. [N-radio-methyl] vorozole substantially separated from an N-3 radio-methyl isomer of vorozole is provided. Separation is accomplished through use of chromatography resins providing multiple mechanisms of selectivity.

Kim, Sung Won; Biegon, Anat; Fowler, Joanna S.

2014-08-05T23:59:59.000Z

230

Radio-methyl vorozole and methods for making and using the same  

DOE Patents [OSTI]

Radiotracer vorozole compounds for in vivo and in vitro assaying, studying and imaging cytochrome P450 aromatase enzymes in humans, animals, and tissues and methods for making and using the same are provided. [N-radio-methyl] vorozole substantially separated from an N-3 radio-methyl isomer of vorozole is provided. Separation is accomplished through use of chromatography resins providing multiple mechanisms of selectivity.

Kim, Sung Won; Biegon, Anat; Fowler, Joanna S.

2014-08-12T23:59:59.000Z

231

INVOLVED IN DE NOVO 2-containing complex involved in RNA-directed DNA methylation in Arabidopsis  

SciTech Connect (OSTI)

At least three pathways control maintenance of DNA cytosine methylation in Arabidopsis thaliana. However, the RNA-directed DNA methylation (RdDM) pathway is solely responsible for establishment of this silencing mark. We previously described INVOLVED IN DE NOVO 2 (IDN2) as being an RNA-binding RdDM component that is required for DNA methylation establishment. In this study, we describe the discovery of two partially redundant proteins that are paralogous to IDN2 and that form a stable complex with IDN2 in vivo. Null mutations in both genes, termed IDN2-LIKE 1 and IDN2-LIKE 2 (IDNL1 and IDNL2), result in a phenotype that mirrors, but does not further enhance, the idn2 mutant phenotype. Genetic analysis suggests that this complex acts in a step in the downstream portion of the RdDM pathway. We also have performed structural analysis showing that the IDN2 XS domain adopts an RNA recognition motif (RRM) fold. Finally, genome-wide DNA methylation and expression analysis confirms the placement of the IDN proteins in an RdDM pathway that affects DNA methylation and transcriptional control at many sites in the genome. Results from this study identify and describe two unique components of the RdDM machinery, adding to our understanding of DNA methylation control in the Arabidopsis genome.

Ausin, Israel; Greenberg, Maxim V.C.; Simanshu, Dhirendra K.; Hale, Christopher J.; Vashisht, Ajay A.; Simon, Stacey A.; Lee, Tzuu-fen; Feng, Suhua; Española, Sophia D.; Meyers, Blake C.; Wohlschlegel, James A.; Patel, Dinshaw J.; Jacobsen, Steven E. (UCLA); (MSKCC); (Delaware)

2012-10-23T23:59:59.000Z

232

Polystyrene/Poly(methyl methacrylate) Blends in the Presence of Cyclohexane: Selective Solvent Washing or Equilibrium Adsorption?  

E-Print Network [OSTI]

-cyclohexane (PS:CH), poly(methyl methacrylate)-carbon tetrachloride (PMMA:CCl4), and PS:CCl4 adsorbing

233

Biogeochemistry of arsenic in natural waters: The importance of methylated species  

SciTech Connect (OSTI)

Water samples from a number of lakes and estuaries, mostly in California, showed measurable concentrations of methylated arsenic (equivalent to 1-59% of total As) with the exception of one highly alkaline lake. Neither depleted phosphate concentrations nor high dissolved salts correlated with the appearance of methylated forms of As. A temporal study of As speciation in Davis Creek Reservoir, a seasonally anoxic lake in northern California, demonstrated that dimethylarsinic acid increased sufficiently to become the dominant form of dissolved As within the surface photic zone during late summer and fall. Methylated forms decreased while arsenate increased when the lake over-turned in early December, which suggested a degradation of dimethylarsinic acid to arsenate.

Anderson, L.C.D.; Bruland, K.W. (Univ. of California, Santa Cruz (USA))

1991-03-01T23:59:59.000Z

234

agents ionising radiation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of poly(methyl methacrylate), poly(n-butyl acrylate) and poly(2-hydroxyethyl (more) Bennet, Francesca 2009-01-01 85 Transcriptomic and Secretomic Profiling of Isolated...

235

aux rayonnements ionisants: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of poly(methyl methacrylate), poly(n-butyl acrylate) and poly(2-hydroxyethyl (more) Bennet, Francesca 2009-01-01 138 Factories: The Ionising Radiations (Sealed Sources)...

236

Multiple Objective Stormwater Management For the Coliseum Complex  

E-Print Network [OSTI]

methyl tertiary butyl ether (MTBE) remain in the soil around5.2 ppb xylenes, and 160 ppb MTBE remain in the groundwater

Jones, Jesse; Kraai, Rachel

2009-01-01T23:59:59.000Z

237

Salt effect on the isobaric vapor-liquid equilibrium of the methyl acetate + methanol system  

SciTech Connect (OSTI)

The effect of sodium thiocyanate at constant salt mole fraction from 0.01 to 0.05 and at saturation on the vapor-liquid equilibrium (VLE) of methyl acetate + methanol has been studied at 101.32 kPa using a modified Othmer equilibrium still. The salt exhibited both salting-in and salting-out effects on the methyl acetate, the azeotrope being eliminated at saturation. The results were correlated using the extended UNIQUAC model of Sander et al. and the electrolytic NRTL model of Mock et al.

Iliuta, M.C.; Thyrion, F.C. [Louvain Univ., Louvain-la-Neuve (Belgium). Chemical Engineering Inst.] [Louvain Univ., Louvain-la-Neuve (Belgium). Chemical Engineering Inst.; Landauer, O.M. [Univ. Politehnica Bucharest (Romania)] [Univ. Politehnica Bucharest (Romania)

1996-07-01T23:59:59.000Z

238

Kinetics of the reduction of methyl viologen with hydrogen on a colloidal Pt catalyst  

SciTech Connect (OSTI)

The evolution of H/sub 2/ on a Pt catalyst under the influence of one-electron reductors is part of the photocatalytic process of decomposition of H/sub 2/O into H/sub 2/ and O/sub 2/. As a model reaction we selected the reduction of methyl viologen. The bonding constant for hydrogen on colloidal Pt, as well as the effective rate constant of the heterolytic splitting of H/sub 2/ on the same Pt catalyst are determined. A mathematical description of the reduction of methyl viologen with hydrogen is suggested.

Maier, V.E.; Shafirovich, V.Ya.

1988-10-01T23:59:59.000Z

239

Acute environmental toxicity and persistence of methyl salicylate: A chemical agent simulant. Final report  

SciTech Connect (OSTI)

The interactions of methyl salicylate with plant foliage and soils were assessed using aerosol/vapor exposure methods. Measurements of deposition velocity and residence times for soils and foliar surfaces are reported. Severe plant contact toxicity was observed at foliar mass-loading levels above 4 {mu}g/cm{sup 2} leaf; however, recovery was noted after four to fourteen days. Methyl salicylate has a short-term effect on soil dehydrogenase activity, but not phosphatase activity. Results of the earthworm bioassay indicated only minimal effects on survival.

Cataldo, D.A.; Ligotke, M.W.; Harvey, S.D.; Fellows, R.J.; Li, S.W.

1994-06-01T23:59:59.000Z

240

Effect of Amino Acid Subsititution in Set1 on Histone H3 Methylation and Gene Silencing in Saaccharomyces Cerevisiae  

E-Print Network [OSTI]

EFFECT OF AMINO ACID SUBSITITUTION IN SET1 ON HISTONE H3 METHYLATION AND GENE SILENCING IN SAACCHAROMYCES CEREVISIAE A Senior Honors Thesis by MORGAN CHATEAU Submitted to the Office...3 Methylation and Gene Silencing in Saccharomyces cerevisiae (April 2008) Morgan Chateau Department of Biochemistry and Biophysics Texas A&M University Fellows Advisor: Associate Professor Dr. Mary Bryk Department of Biochemistry...

Chateau, Morgan

2008-08-24T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Electronic structure calculations of radical reactions for poly(methyl methacrylate) degradation  

E-Print Network [OSTI]

exposed to UV light in low-Earth orbit (LEO) conditions experience degradation. Under LEO conditionsElectronic structure calculations of radical reactions for poly(methyl methacrylate) degradation to calculate the reaction energetics for decomposition reactions of radicals formed from UV radiation

242

Sequential 2 -O-Methylation of Archaeal Pre-tRNATrp Nucleotides  

E-Print Network [OSTI]

Sequential 2 -O-Methylation of Archaeal Pre-tRNATrp Nucleotides Is Guided by the Intron -O-methyla- tion of nucleotides C34 and U39 followed by intron exci- sion. Positioning of the box C proteins. With both kinetic studies and single nucleotide substitutions of target and guide nucleotides, we

Maxwell, E. Stuart

243

Selective Methylation Changes on the Bacillus subtilis Chemotaxis Receptor McpB Promote Adaptation*  

E-Print Network [OSTI]

. In the same background, McpB(E630D,E637D) produced methanol only upon aspara- gine addition, whereas McpB(Q371D,E630D) produced methanol only upon asparagine removal. Thus methanol release from Mcp, from which methanol is released in response to all stimuli. McpB has four putative methylation sites

Ordal, George W.

244

Infrared Study of the Molecular Orientation in Ultrathin Films of Behenic Acid Methyl Ester: Comparison between  

E-Print Network [OSTI]

Infrared Study of the Molecular Orientation in Ultrathin Films of Behenic Acid Methyl Ester-Blodgett transfer. The presence in the infrared spectra of several bands due to the methylene wagging and twisting and infrared spectroscopy have been developed to study these films. Infrared spectroscopy is particularly

Pezolet, Michel

245

Active transport, substrate specificity, and methylation of Hg(II) in anaerobic bacteria  

SciTech Connect (OSTI)

The formation of methylmercury (MeHg), which is biomagnified in aquatic food chains and poses a risk to human health, is effected by some iron- and sulfate-reducing bacteria (FeRB and SRB) in anaerobic environments. However, very little is known regarding the mechanism of uptake of inorganic Hg by these organisms, in part because of the inherent difficulty in measuring the intracellular Hg concentration. By using the FeRB Geobacter sulfurreducens and the SRB Desulfovibrio desulfuricans ND132 as model organisms, we demonstrate that Hg(II) uptake occurs by active transport. We also establish that Hg(II) uptake by G. sulfurreducens is highly dependent on the characteristics of the thiols that bind Hg(II) in the external medium, with some thiols promoting uptake and methylation and others inhibiting both. The Hg(II) uptake system of D. desulfuricans has a higher affinity than that of G. sulfurreducens and promotes Hg methylation in the presence of stronger complexing thiols. We observed a tight coupling between Hg methylation and MeHg export from the cell, suggesting that these two processes may serve to avoid the build up and toxicity of cellular Hg. Our results bring up the question of whether cellular Hg uptake is specific for Hg(II) or accidental, occurring via some essential metal importer. Our data also point at Hg(II) complexation by thiols as an important factor controlling Hg methylation in anaerobic environments.

Schasfer, Jeffra [Princeton University; Rocks, Sara [Princeton University; Zheng, Wang [ORNL; Liang, Liyuan [ORNL; Gu, Baohua [ORNL; Morel, Francois M [ORNL

2011-01-01T23:59:59.000Z

246

Biodegradation of triclosan and formation of methyl-triclosan in activated sludge under aerobic conditions  

E-Print Network [OSTI]

Biodegradation of triclosan and formation of methyl-triclosan in activated sludge under aerobic in activated sludge from a standard activated sludge WWTP equipped with enhanced biological phosphorus removal) and anaerobic conditions rather low removal rates were determined. In a laboratory-scale activated sludge

Kolaei, Alireza Rezania

247

Combustion chemical kinetics of biodiesel and related compounds (methyl and ethyl esters): Experiments and  

E-Print Network [OSTI]

1 Combustion chemical kinetics of biodiesel and related compounds (methyl and ethyl esters transportation fuel dedicated to the diesel engine, biodiesel, with an emphasis on ethyl esters because of biodiesel and related components, the main gaps in the field are highlighted to facilitate the convergence

Paris-Sud XI, Université de

248

Growth of diamond films using an enclosed methyl-acetylene and propadiene combustion flame  

E-Print Network [OSTI]

1 Growth of diamond films using an enclosed methyl-acetylene and propadiene combustion flame K Abstract Diamond growth in low pressure combustion flames was studied using a safer, more economical and chemical kinetic time scales in the combustion reactor. 1 Present Address: 3M Corporation, Bldg. 60-1N-01

Dandy, David

249

Methylation of Mercury by Bacteria Exposed to Dissolved, Nanoparticulate, and Microparticulate Mercuric Sulfides  

E-Print Network [OSTI]

Methylation of Mercury by Bacteria Exposed to Dissolved, Nanoparticulate, and Microparticulate in the environment is partly controlled by the bioavailability of inorganic divalent mercury (Hg(II)) to anaerobic matter to form chemical species that include organic-coated mercury sulfide nanoparticles as reaction

250

Neutralization of Methyl Cation via Chemical Reactions in Low-Energy Ion-Surface  

E-Print Network [OSTI]

with Fluorocarbon and Hydrocarbon Self-Assembled Monolayer Films A´ rpa´d Somogyi, Darrin L. Smith, and Vicki H-surface collisions of methyl cation at hydrocarbon and fluorocarbon self- assembled monolayer (SAM) surfaces produce with hydrocarbon and fluorocarbon SAMs occurs by concerted chemical reactions, i.e., that neutralization

Wysocki, Vicki H.

251

Original article Novel attractants of Galleria mellonella L  

E-Print Network [OSTI]

, 1957). Methyl, ethyl, propyl, butyl, allyl esters of octanoic and decanoic acids were synthesized via the reaction of the corre- sponding acid chlorides and alcohols. Decyl and octyl acetates, methyl, ethyl

Boyer, Edmond

252

Spectroscopic investigation of the vibrational quasi-continuum arising from internal rotation of a methyl group  

SciTech Connect (OSTI)

The goal of this project is to use spectroscopic techniques to investigate in detail phenomena involving the vibrational quasi-continuum in a simple physical system. Acetaldehyde was chosen for the study because: (i) methyl groups have been suggested to be important promotors of intramolecular vibrational relaxation, (ii) the internal rotation of a methyl group is an easily describle large-amplitude motion, which should retain its simple character even at high levels of excitation, and (iii) the aldehyde carbonyl group offers the possibility of both vibrational and electronic probing. The present investigation of the ground electronic state has three parts: (1) understanding the {open_quotes}isolated{close_quotes} internal-rotation motion below, at, and above the top of the torsional barrier, (2) understanding in detail traditional (bond stretching and bending) vibrational fundamental and overtone states, and (3) understanding interactions involving states with multiquantum excitations of at least one of these two kinds of motion.

Hougen, J.T. [NIST, Gaithersburg, MD (United States)

1993-12-01T23:59:59.000Z

253

ALMA imaging study of methyl formate (HCOOCH$_{3}$) in the torsionally excited states towards Orion KL  

E-Print Network [OSTI]

We recently reported the first identification of rotational transitions of methyl formate (HCOOCH$_{3}$) in the second torsionally excited state toward Orion Kleinmann-Low (KL) observed with the Nobeyama 45 m telescope. In combination with the identified transitions of methyl formate in the ground state and the first torsional excited state, it was found that there is a difference in rotational temperature and vibrational temperature, where the latter is higher. In this study, high spatial resolution analysis by using Atacama Large Millimeter/Submillimeter Array (ALMA) science verification data was carried out to verify and understand this difference. Toward the Compact Ridge, two different velocity components at 7.3 and 9.1 km s$^{-1}$ were confirmed, while a single component at 7.3 km s$^{-1}$ was identified towards the Hot Core. The intensity maps in the ground, first, and second torsional excited states have quite similar distributions. Using extensive ALMA data, we determined the rotational and vibration...

Sakai, Yusuke; Hirota, Tomoya

2015-01-01T23:59:59.000Z

254

Experimental investigation of size effect on thermal conductivity for ultra-thin amorphous poly(methyl methacrylate) (PMMA) films  

E-Print Network [OSTI]

An investigation was conducted to determine whether a “size effect” phenomenon for one particular thermophysical property, thermal conductivity, actually exists for amorphous poly(methyl methacrylate) (PMMA) films with thicknesses ranging from 40 nm...

Kim, Ick Chan

2009-05-15T23:59:59.000Z

255

CORRELATION OF DNA METHYLATION WITH MERCURY CONTAMINATION IN MARINE ORGANISMS: A CASE STUDY OF NOAA MUSSEL WATCH TISSUE SAMPLES  

E-Print Network [OSTI]

American oysters (Crassostrea virginica) obtained from the NOAA Mussel Watch program were screened for DNA methylation, a type of epigenetic response to stressors. Oysters were collected from sites in the Gulf of Mexico having high mercury...

Brinkmeyer, Robin; Taylor, Robert; Germ, Kaylyn E.

2011-08-04T23:59:59.000Z

256

An assessment of methyl mercury and volatile mercury in land-applied sewage sludge  

SciTech Connect (OSTI)

In 1993, the US Environmental Protection Agency issued regulations covering the land-application of municipal sewage sludge. These regulations established maximum pollutant concentrations and were based upon a risk assessment of human exposure. Mercury, assumed to be inorganic and non-volatile, was one pollutant evaluated. From April, 1995 through February, 1996, the authors studied the species of mercury contaminating municipal sludge applied to land, and the potential for volatilization of mercury from land-applied sludge. Methyl mercury was found at 0.1% of total mercury concentrations and was emitted from land-applied sludge to the atmosphere. Elemental mercury (Hg) was formed in land-applied sludge via the reduction of oxidized mercury and was also emitted to the atmosphere. Hg emission from land-applied sludge was significantly elevated over background soil emission. Methyl mercury is more toxic and more highly bioaccumulated than inorganic mercury, and warrants assessment considering these special criteria. Additionally, mercury emission from sludge-amended soil may lead to the contamination of other environmental media with significant concentrations of the metal. Although these pathways were not evaluated in the regulatory risk assessment, they are an important consideration for evaluating the risks from mercury in land-applied sludge. This presentation will summarize the results of a re-assessment of US EPA regulations regarding the land-application of municipal sewage sludge using data on methyl mercury toxicity and mercury transport in the atmosphere.

Carpi, A. [Cornell Univ., Ithaca, NY (United States); Lindberg, S.E. [Oak Ridge National Lab., TN (United States)

1995-12-31T23:59:59.000Z

257

Arsenic methylation capability and hypertension risk in subjects living in arseniasis-hyperendemic areas in southwestern Taiwan  

SciTech Connect (OSTI)

Background: Cumulative arsenic exposure (CAE) from drinking water has been shown to be associated with hypertension in a dose-response pattern. This study further explored the association between arsenic methylation capability and hypertension risk among residents of arseniasis-hyperendemic areas in Taiwan considering the effect of CAE and other potential confounders. Method: There were 871 subjects (488 women and 383 men) and among them 372 were diagnosed as having hypertension based on a positive history or measured systolic blood pressure {>=} 140 mm Hg and/or diastolic blood pressure {>=} 90 mm Hg. Urinary arsenic species were determined by high-performance liquid chromatography-hydride generator and atomic absorption spectrometry. Primary arsenic methylation index [PMI, defined as monomethylarsonic acid (MMA{sup V}) divided by (As{sup III} + As{sup V})] and secondary arsenic methylation index (SMI, defined as dimethylarsinic acid divided by MMA{sup V}) were used as indicators for arsenic methylation capability. Results: The level of urinary arsenic was still significantly correlated with cumulative arsenic exposure (CAE) calculated from a questionnaire interview (p = 0.02) even after the residents stopped drinking the artesian well water for 2-3 decades. Hypertensive subjects had higher percentages of MMA{sup V} and lower SMI than subjects without hypertension. However, subjects having CAE > 0 mg/L-year had higher hypertension risk than those who had CAE = 0 mg/L-year disregard a high or low methylation index. Conclusion: Inefficient arsenic methylation ability may be related with hypertension risk.

Huang, Y.-K. [Graduate Institute of Medical Sciences, School of Medicine, Taipei Medical University, Taipei, Taiwan (China); Tseng, C.-H. [National Taiwan University College of Medicine, Taipei, Taiwan (China); Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan (China); Department of Medical Research and Development, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan (China); Huang, Y.-L. [Department of Public Health, School of Medicine, Taipei Medical University, No. 250 Wu-Hsing Street, Taipei 110, Taiwan (China); Yang, M.-H. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu, Taiwan (China); Chen, C.-J. [Genomic Research Center, Academia Sinica, Taipei, Taiwan (China); Graduate Institute of Epidemiology, College of Public Health, National Taiwan University Taipei, Taiwan (China); Hsueh, Y.-M. [Department of Public Health, School of Medicine, Taipei Medical University, No. 250 Wu-Hsing Street, Taipei 110, Taiwan (China)]. E-mail: ymhsueh@tmu.edu.tw

2007-01-15T23:59:59.000Z

258

UNIVERSITY OF CALIFORNIA Santa Barbara  

E-Print Network [OSTI]

, B. Dooher, and D. Rice, Analysis of dissolved benzene plumes and methyl tertiary butyl ether (MTBE, An evaluation of MTBE impacts to California groundwater resources, pp. 68 p., Lawrence Livermore National, Temporal Analysis of Methyl Tertiary Butyl Ether (MTBE) Plumes at California Leaking Underground Fuel tank

California at Santa Barbara, University of

259

Exposure to di(n-butyl)phthalate and benzo(a)pyrene alters IL-1{beta} secretion and subset expression of testicular macrophages, resulting in decreased testosterone production in rats  

SciTech Connect (OSTI)

Di(n-butyl)phthalate (DBP) and benzo(a)pyrene (BaP) are environmental endocrine disruptors that are potentially hazardous to humans. These chemicals affect testicular macrophage immuno-endocrine function and testosterone production. However, the underlying mechanisms for these effects are not fully understood. It is well known that interleukin-1 beta (IL-1{beta}), which is secreted by testicular macrophages, plays a trigger role in regulating Leydig cell steroidogenesis. The purpose of this study was to reveal the effects of co-exposure to DBP and BaP on testicular macrophage subset expression, IL-1{beta} secretion and testosterone production. Adult male Sprague-Dawley rats were randomly divided into seven groups; two groups received DBP plus BaP (DBP + BaP: 50 + 1 or 250 + 5 mg/kg/day) four groups received DBP or BaP alone (DBP: 50 or 250 mg/kg/day; BaP: 1 or 5 mg/kg/day), and one group received vehicle alone (control). After co-exposure for 90 days, the relative expression of macrophage subsets and their functions changed. ED2{sup +} testicular macrophages (reactive with a differentiation-related antigen present on the resident macrophages) were activated and IL-1{beta} secretion was enhanced. DBP and BaP acted additively, as demonstrated by greater IL-1{beta} secretion relative to each compound alone. These observations suggest that exposure to DBP plus BaP exerted greater suppression on testosterone production compared with each compound alone. The altered balance in the subsets of testicular macrophages and the enhanced ability of resident testicular macrophages to secrete IL-1{beta}, resulted in enhanced production of IL-1{beta} as a potent steroidogenesis repressor. This may represent an important mechanism by which DBP and BaP repress steroidogenesis.

Zheng Shanjun [Department of High Altitude Military Hygiene, College of High Altitude Military Medicine, Third Military Medical University, Chongqing 400038 (China); Key Laboratory of High Altitude Medicine, Ministry of Education, Chongqing 400038 (China); Key Laboratory of High Altitude Physiology and High Altitude Disease, PLA, Chongqing 400038 (China); Tian Huaijun, E-mail: huaijunt@sohu.co [Department of High Altitude Military Hygiene, College of High Altitude Military Medicine, Third Military Medical University, Chongqing 400038 (China); Key Laboratory of High Altitude Medicine, Ministry of Education, Chongqing 400038 (China); Key Laboratory of High Altitude Physiology and High Altitude Disease, PLA, Chongqing 400038 (China); Cao Jia [Department of Hygienic Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing 400038 (China); Gao Yuqi, E-mail: yanhua007_007@hotmail.co [Department of High Altitude Military Hygiene, College of High Altitude Military Medicine, Third Military Medical University, Chongqing 400038 (China); Key Laboratory of High Altitude Medicine, Ministry of Education, Chongqing 400038 (China); Key Laboratory of High Altitude Physiology and High Altitude Disease, PLA, Chongqing 400038 (China)

2010-10-01T23:59:59.000Z

260

Endonuclease IV of Escherichia coli is induced by paraquat  

SciTech Connect (OSTI)

The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H/sub 2/O/sub 2/ produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, ..gamma.. rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O/sub 2/. The levels of endonuclease IV in uninduced or paraquat-treated cells were unaffected by mutations of oxyR, a H/sub 2/O/sub 2/-inducible gene that governs an oxidative-stress regulon. The results indicate that endonuclease IV is an inducible DNA-repair enzyme and that its induction can be mediated via the production of superoxide radicals.

Chan, E.; Weiss, B.

1987-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

The interaction of organic adsorbate vibrations with substrate lattice waves in methyl-Si(111)-(1?×?1)  

SciTech Connect (OSTI)

A combined helium atom scattering and density functional perturbation theory study has been performed to elucidate the surface phonon dispersion relations for both the CH{sub 3}-Si(111)-(1?×?1) and CD{sub 3}-Si(111)-(1?×?1) surfaces. The combination of experimental and theoretical methods has allowed characterization of the interactions between the low energy vibrations of the adsorbate and the lattice waves of the underlying substrate, as well as characterization of the interactions between neighboring methyl groups, across the entire wavevector resolved vibrational energy spectrum of each system. The Rayleigh wave was found to hybridize with the surface rocking libration near the surface Brillouin zone edge at both the M{sup ¯}-point and K{sup ¯}-point. The calculations indicated that the range of possible energies for the potential barrier to the methyl rotation about the Si-C axis is sufficient to prevent the free rotation of the methyl groups at a room temperature interface. The density functional perturbation theory calculations revealed several other surface phonons that experienced mode-splitting arising from the mutual interaction of adjacent methyl groups. The theory identified a Lucas pair that exists just below the silicon optical bands. For both the CH{sub 3}- and CD{sub 3}-terminated Si(111) surfaces, the deformations of the methyl groups were examined and compared to previous experimental and theoretical work on the nature of the surface vibrations. The calculations indicated a splitting of the asymmetric deformation of the methyl group near the zone edges due to steric interactions of adjacent methyl groups. The observed shifts in vibrational energies of the -CD{sub 3} groups were consistent with the expected effect of isotopic substitution in this system.

Brown, Ryan D.; Hund, Zachary M.; Sibener, S. J., E-mail: s-sibener@uchicago.edu [The James Franck Institute and Department of Chemistry, The University of Chicago, 929 E. 57th Street, Chicago, Illinois 60637 (United States); Campi, Davide; Bernasconi, M. [Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy); O’Leary, Leslie E.; Lewis, Nathan S. [Beckman Institute and Kavli Nanoscience Institute, Division of Chemistry and Chemical Engineering, 210 Noyes Laboratory, 127-72, California Institute of Technology, Pasadena, California 91125 (United States); Benedek, G. [Dipartimento di Scienza dei Materiali, Universitá di Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy); Donostia International Physics Center (DIPC), Universidad del País Vasco (EHU), 20018 Donostia / San Sebastian (Spain)

2014-07-14T23:59:59.000Z

262

Electrochemical investigation of the energetics of particulate titanium dioxide photocatalysts. The methyl viologen-acetate system  

SciTech Connect (OSTI)

Addition of methyl viologen (MV/sup 2 +/) enhances the anodic currents observed for TiO/sub 2/ suspensions under illumination by trapping of photogenerated electrons with formation of MV/sup +/. The magnitude of the photocurrent depends upon the relative location of the semiconductor Fermi level and E/sub redox/ of the MV/sup 2 +//MV/sup +/.couple. The location of the Fermi level in the anatase powders was estimated as -0.05 V vs. NHE (pH 0) based on the observed variation of photocurrent with pH. The shift in the quasi-Fermi level with light intensity is also discussed.

Ward, M.D.; White, J.R.; Bard, A.J.

1983-01-12T23:59:59.000Z

263

Storage effects on desorption efficiencies of methyl ethyl ketone and styrene collected on activated charcoal  

E-Print Network [OSTI]

in the worker ' s breathir ng zone cont ir uously during his working day. Solid ad- sorbents are used almost exclusively I' or this type of sampling. Among the marr, adsorbents avail able (s ! i ca gel, activated alumina, Tenax, etc. } acti&!ated charcoa&1 I... efficier&cy nf methyl etiiy', Ketone and styrene monomer adsorbed on activated charcoal samples, and stored under isotherm&al condit'ions, were investigated as a function of storage time. The dependence of the storage time effects on the storage temp...

Dommer, Richard Alvin

1978-01-01T23:59:59.000Z

264

A circadian rhythm in the susceptibility of the boll weevil, Anthonomus grandis Boheman to methyl parathion  

E-Print Network [OSTI]

and for his assistance in the preparation of the manuscript. Apprecia tion is also extended to Dr. J. C. Gaines, Dr. R. L. Hanna, Mr. N. M. Randolph, and Dr. R. D. Staten for their suggestions and criticisms in the preparation of this manuscript. TABLE...:14, decapitated and then held in LL for 10 days. (D) Held in LD 10:14 for 10 days, decapitated and then held for 10 more days in LD 10:14 LD 50 values obtained from topical appli- cations of methyl parathion to boll weevlls at various times of day'. The LD...

Cole, Charles L

1967-01-01T23:59:59.000Z

265

Thiophanate-methyl, persistence in soybeans and effects on yield, seed quality, emergence and nodulation  

E-Print Network [OSTI]

containing natural rhizobia populations. Persistence of the fungitoxic TM product, methyl-2-benzimidazole- carbamate (MBC) in/on soybeans was determined spectrophotometrically after once and twice spraying TM (1. 10 kg/ha a. i. ). In once-sprayed tissues... planting. Efficac of TM as a foliar fun icide. Untreated Bragg and Coker 338 soybeans were planted as above. When pods reached 1-2 cm length (Sept. 21), the soybeans were sprayed with TM (Topsin-M 70 WP) at 1. 10 kg/ha a. i. and again 18 days later...

Lyons, Philip Christopher

1981-01-01T23:59:59.000Z

266

In-cylinder pressure characteristics of a CI engine using blends of diesel fuel and methyl esters of beef tallow  

SciTech Connect (OSTI)

A Cummins N14-410 diesel engine was operated on 12 fuels produced by blending methyl tallowate, methyl soyate, and ethanol with no. 2 diesel fuel. Engine in-cylinder pressure data were used to evaluate engine performance. Peak cylinder pressures for each fuel blend at all engine speeds were lower than peak pressure for diesel fuel with the exception of the 80% diesel, 13% methyl tallowate, and 7% ethanol; and the 80% diesel, 6.5% methyl tallowate, 6.5% methyl soyate and 7% ethanol blends. The indicated mean effective pressure (IMEP) values for all fuel blends were less than for diesel fuel. The differences in IMEP values correlated with differences in power output of the engine. Similarly, maximum rates of pressure rise for most fuel blends were less than for diesel fuel. It was concluded that the fuel blends used in this study would have no detrimental long-term effects on engine performance, wear, and knock. 6 refs., 4 figs., 7 tabs.

Ali, Y.; Hanna, M.A.; Borg, J.E. [Univ. of Nebraska, Lincoln, NE (United States)

1996-05-01T23:59:59.000Z

267

Characterization of the Deltaproteobacteria in Contaminated and Uncontaminated Surface Stream Sediments and Identification of Potential Mercury Methylators  

SciTech Connect (OSTI)

Microbial communities were examined in surface stream sediments at five contaminated sites and one control site near Oak Ridge, TN in order to identify bacteria that could be contributing to mercury methylation. The phylogenetic composition of the sediment bacterial community was examined over three quarterly sampling periods (36 samples) using 16s rRNA pyrosequencing. Only 3064 sequences (0.85 % of the total community) were identified as Deltaproteobacteria by the RDP classifier at the 99% confidence threshold. Constrained ordination techniques indicated significant positive correlations between Desulfobulbus spp., Desulfonema spp. and Desulfobacca spp. and methyl mercury concentrations in the contaminated sites. On the contrary, the distribution of organisms related to Byssovorax was significantly correlated to inorganic carbon, nitrate and uranium concentrations. Overall, the abundance and richness of Deltaproteobacteria sequences were higher in the sediments of the site, while the majority of the members present at the contaminated sites were either known metal reducers/methylators or metal tolerant species.

Mosher, Jennifer J [ORNL; Vishnivetskaya, Tatiana A [ORNL; Elias, Dwayne A [ORNL; Podar, Mircea [ORNL; Brooks, Scott C [ORNL; Brown, Steven D [ORNL; Brandt, Craig C [ORNL; Palumbo, Anthony Vito [ORNL

2012-01-01T23:59:59.000Z

268

Mode of action of ethyl tertiary-butyl ether hepatotumorigenicity in the rat: Evidence for a role of oxidative stress via activation of CAR, PXR and PPAR signaling pathways  

SciTech Connect (OSTI)

To elucidate possible mode of action (MOA) and human relevance of hepatotumorigenicity in rats for ethyl tertiary-butyl ether (ETBE), male F344 rats were administered ETBE at doses of 0, 150 and 1000 mg/kg body weight twice a day by gavage for 1 and 2 weeks. For comparison, non-genotoxic carcinogen phenobarbital (PB) was applied at a dose of 500 ppm in diet. Significant increase of P450 total content and hydroxyl radical levels by low, high doses of ETBE and PB treatments at weeks 1 and 2, and 8-OHdG formation at week 2, accompanied accumulation of CYP2B1/2B2, CYP3A1/3A2 and CYP2C6, and downregulation of DNA oxoguanine glycosylase 1, induction of apoptosis and cell cycle arrest in hepatocytes, respectively. Up-regulation of CYP2E1 and CYP1A1 at weeks 1 and 2, and peroxisome proliferation at week 2 were found in high dose ETBE group. Results of proteome analysis predicted activation of upstream regulators of gene expression altered by ETBE including constitutive androstane receptor (CAR), pregnane-X-receptor (PXR) and peroxisome proliferator-activated receptors (PPARs). These results indicate that the MOA of ETBE hepatotumorigenicity in rats may be related to induction of oxidative stress, 8-OHdG formation, subsequent cell cycle arrest, and apoptosis, suggesting regenerative cell proliferation after week 2, predominantly via activation of CAR and PXR nuclear receptors by a mechanism similar to that of PB, and differentially by activation of PPARs. The MOA for ETBE hepatotumorigenicity in rats is unlikely to be relevant to humans. - Highlights: • We focus on MOA and human relevance of hepatotumorigenicity in rats for ETBE. • ETBE was administered to F344 rats for 1 and 2 weeks. • Oxidative stress formation, proliferation and apoptosis in the liver are analyzed. • ETBE-induced changes of gene and protein expression in the liver are examined. • The effects are compared with those induced by non-genotoxic carcinogen PB.

Kakehashi, Anna, E-mail: anna@med.osaka-cu.ac.jp [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan); Hagiwara, Akihiro; Imai, Norio [DIMS Institute of Medical Science, Inc., 64 Goura, Nishiazai, Azai-cho, Ichinomiya, Aichi 491-0113 (Japan); Nagano, Kasuke [Nagano Toxicologic-Pathology Consulting, Ochiai, Hadano, Kanagawa 257-0025 (Japan); Nishimaki, Fukumi [Biofuel Assessment Group, New Fuels Dept., Japan Petroleum Energy Center (JPEC), 4-3-9 Toranomon, Minato-ku, Tokyo 105-0001 (Japan); Banton, Marcy [Toxicology and Risk Assessment, LyondellBasell Industries, LyondellBasell Corporate HSE/Product Safety, One Houston Center, Suite 700, 1221 McKinney Street, Houston, TX 770 10 (United States); Wei, Min [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan); Fukushima, Shoji [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan); Japan Bioassay Research Center, Japan Industrial Safety and Health Association, 2445 Hirasawa, Hadano, Kanagawa 257-0011 (Japan); Wanibuchi, Hideki [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan)

2013-12-01T23:59:59.000Z

269

Desorption of carbon monoxide from nickel using mercaptans  

SciTech Connect (OSTI)

An IR spectroscopic study on the displacement of carbon monoxide with 1-propyl, 2-propyl-, 1-butyl-, 2-butyl-, and tert.-butyl mercaptan from nickel foil and silica-supported nickel showed that at low carbon monoxide coverage on supported nickel, mercaptan adsorption initially converted bridged to linear carbon monoxide surface species. At higher mercaptan pressures, carbon monoxide desorbed into the gas phase. A small amount of carbon monoxide remained on the surface when the poisoned sample was evacuated, and additional carbon monoxide adsorbed when 5 mm Hg of carbon monoxide was added to the evacuated sample.

Neff, L.D.; Sturdivant, A.E.; Wallace, J.L.

1980-06-01T23:59:59.000Z

270

A Solid-State NMR Study of Tungsten Methyl Group Dynamics in [W(5-C5Me5)Me4][PF6  

E-Print Network [OSTI]

A Solid-State NMR Study of Tungsten Methyl Group Dynamics in [W(5-C5Me5)Me4][PF6] Douglas C. Maus Spinning (MAS) 13C and static 2H NMR studies of the dynamics of the methyl groups coordinated to tungsten

Griffin, Robert G.

271

Long-Range Ferromagnetic Ordering in Two-Dimensional Coordination Polymers Co[N(CN)2]2(L) [L ) Pyrazine Dioxide (pzdo) and 2-Methyl  

E-Print Network [OSTI]

) Pyrazine Dioxide (pzdo) and 2-Methyl Pyrazine Dioxide (mpdo)] with Dual µ- and µ3-[N(CN)2] Bridges Hao by the addition of ancillary ligands of pyrazine dioxide (pzdo) and 2-methyl pyrazine dioxide (mpdo) into the Co]- , possesses three coordination nitrogen atoms and several possible coordination modes: terminal, bidentate 1

Gao, Song

272

EINLADUNG INFOTAG 2001 Eine Forschungsanstalt  

E-Print Network [OSTI]

durch den Benzinzusatz MTBE. Methyl-tert-butylether gehört weltweit zu den meistproduzierten orga- nischen Chemikalien. Weil MTBE im Grundwasser auftritt, soll es in den USA als Benzinzusatz verboten

Wehrli, Bernhard

273

LANXESS Global Butyl Rubber Research Facility  

E-Print Network [OSTI]

Park, in partnership with Surface Science Western $10million City of London Investment in Fraunhofer- fraunhofer Agreement chosen to highlight celebrations for 40th Anniversary of Canada-Germany cooperation fuel cluster in Sarnia-Lambton, said Sarnia Mayor Mike Bradley, noting the Bioindustrial Innovation

Denham, Graham

274

Cytoprotective Effects of Dietary Fatty Acids on Oxidative Stress in Hepatocytes  

E-Print Network [OSTI]

common dietary fatty acids to subsequent inflammation and stress. Hepatocytes (HepG2 cell line) were treated with oleic, linoleic and palmitic acid at different concentrations and exposed to the pro-oxidant tert-butyl hydroperoxide (t-BHP) to induce...

Richardson, Thomas C

2012-07-11T23:59:59.000Z

275

JOURNALDE PHYSIQUEIV ColloqueC8, supplbmentau Journal de Physique I, Volume 3,dicembre1993  

E-Print Network [OSTI]

-Telechelic Polymers (HTP) has been prepared. Prelerninary SAXS results on a,w - carboxy poly (tert. butyl acrylate patterns. A new class of model ionomers has been developed in Liege: the Halato-Telechelic Polymers. HTP and discussion All the experimentsperformed until now confirm the multi-peak structure of the new HTP's at low

Boyer, Edmond

276

Heterogeneous catalyst for the production of acetic anhydride from methyl acetate  

DOE Patents [OSTI]

This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

Ramprasad, D.; Waller, F.J.

1999-04-06T23:59:59.000Z

277

Heterogeneous catalyst for the production of acetic anhydride from methyl acetate  

DOE Patents [OSTI]

This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

Ramprasad, Dorai (Allentown, PA); Waller, Francis Joseph (Allentown, PA)

1999-01-01T23:59:59.000Z

278

Isomerization of methyl linoleate on ruthenium(III) alkoxide complex; Mathematical modeling  

SciTech Connect (OSTI)

The isomerization of methyl linoleate using ruthenium alkoxide complexes is described. With alcohols, such as isopropyl alcohol (IPA), 1-butanol, 1-hexanol, and 1-octanol, isomerization of double bonds to produce a conjugated system is the main reaction, with hydrogenation being the side reaction. The latter is formed via the conjugated product. Based on kinetic and infrared spectroscopic data, it is concluded that the active catalytic species is a ruthenium hydride complex formed by the decomposition of the unstable alkoxide. The reaction is mathematically modeled, and the rate parameters are obtained by fitting the simulation to experimental data. These values are compared with data obtained from reactions carried out with supported ruthenium-nickel heterogeneous catalyst.

Mukesh, D.; Narasimhan, C.S.; Ramnarayan, K.; Deshpande, V.M

1989-08-01T23:59:59.000Z

279

Embedded Piezoresistive Microcantilever Sensors Functionalized for the Detection of Methyl Salicylate  

SciTech Connect (OSTI)

Sensors designed to detect the presence of methyl salicylate (MeS) have been tested. These sensors use a sensor platform based on the embedded piezoresistive microcantilever (EPM) design. Sensing materials tested in this study included the polymer poly (ethylene vinyl acetate), or PEVA as well as a composite sensing material consisting of the enzyme SA-binding protein 2, or SABP-2. The SABP-2 was immobilized within a biocompatible Hypol gel matrix. The PEVA-based sensors exhibited slower but reversible responses to MeS vapors, recovering fully to their initial state after the analyte was removed. SABP-2 sensors exhibited faster overall response to the introduction of MeS, responding nearly instantly. These sensors, however, do not recover after exposures have ended. Sensors using the SABP-2 sensing materials act instead as integrating sensors, measuring irreversibly the total MeS dose obtained.

Porter, T. L. [UNLV; Venedam, R. J. [NSTec

2013-03-01T23:59:59.000Z

280

Methyl Chloride from Direct Methane Partial Oxidation: A High-Temperature Shilov-Like Catalytic System  

SciTech Connect (OSTI)

The intention of this study is to demonstrate and evaluate the scientific and economic feasibility of using special solvents to improve the thermal stability of Pt-catalyst in the Shilov system, such that a high reaction temperature could be achieved. The higher conversion rate (near 100%) of methyl chloride from partial oxidation of methane under the high temperature ({approx} 200 C) without significant Pt0 precipitation has been achieved. High concentration of the Cl- ion has been identified as the key for the stabilization of the Pt-catalysts. H/D exchange measurements indicated that the over oxidation will occur at the elevated temperature, developments of the effective product separation processes will be necessary in order to rationalize the industry-visible CH4 to CH3Cl conversion.

Yongchun Tang; John (Qisheng) Ma

2012-03-23T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Liquid-liquid equilibria of the ternary system water + acetic acid + 2-methyl-2-butanol  

SciTech Connect (OSTI)

Liquid-liquid equilibria for the ternary system water + acetic acid + 2-methyl-2-butanol were measured over a temperature range of (288 to 323) K. The results were used to estimate the interaction parameters between each of the three compounds for the NRTL and UNIQUAC models and between each of the main groups of H{sub 2}O, CH{sub 2} (paraffinic CH{sub 2}), OH, and COOH for the UJNIFAC model as a function of temperature. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the three models. The NRTL equation was the most accurate model in correlating the overall equilibrium compositions of the studied system. The UNIFAC model satisfactorily predicted the equilibrium compositions.

Fahim, M.A.; Al-Muhtaseb, S.A. [United Arab Emirates Univ., Al-Ain (United Arab Emirates). Dept. of Chemical and Petroleum Engineering] [United Arab Emirates Univ., Al-Ain (United Arab Emirates). Dept. of Chemical and Petroleum Engineering

1996-11-01T23:59:59.000Z

282

Homogeneous Hydrogenation of CO2 to Methyl Formate Utilizing Switchable Ionic Liquids  

SciTech Connect (OSTI)

Capture of CO2 and subsequent hydrogenation allows for base/alcohol-catalyzed conversion of CO2 to methylformate in one pot. The conversion of CO2 proceeds via alkylcarbonates, to formate salts and then formate esters, which can be catalyzed by base and alcohol with the only byproduct being water. The system operates at mild conditions (300 psi H2, 140 ?C). Reactivity is strongly influenced by temperature and choice of solvent. In the presence of excess of base (DBU) formate is predominant product while in excess of methanol methyl formate is major product. 110 ?C yields formate salts, 140 ?C promotes methylformate. The authors acknowledge internal Laboratory Directed Re-search and Development (LDRD) funding from Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for the U.S. Department of Energy.

Yadav, Mahendra (ORCID:0000000202660382); Linehan, John C.; Karkamkar, Abhijeet J.; Van Der Eide, Edwin F.; Heldebrant, David J.

2014-09-15T23:59:59.000Z

283

Interactions in 1-ethyl-3-methyl imidazolium tetracyanoborate ion pair: Spectroscopic and density functional study  

SciTech Connect (OSTI)

Density Functional Theory is used to investigate a weakly coordinating room-temperature ionic liquid, 1-ethyl-3-methyl imidazolium tetracyanoborate ([Emim]{sup +}[TCB]{sup -}). Four locally stable conformers of the ion pair were located. Atoms-in-molecules (AIM) and electron density analysis indicated the existence of several hydrogen bonds. Further investigation through the Natural Bond Orbital (NBO) and Natural Energy Decomposition Analysis (NEDA) calculations provided insight into the origin of interactions in the [Emim]{sup +}[TCB]{sup -} ion pair. Strength of molecular interactions in the ionic liquid was correlated with frequency shifts of the characteristic vibrations of the ion pair. Harmonic vibrations of the ion pair were also compared with the experimental Raman and Infrared spectra. Vibrational frequencies were assigned by visualizing displacements of atoms around their equilibrium positions and through Potential Energy Distribution (PED) analysis.

Mao, James X.; Lee, Anita S.; Kitchin, John R.; Nulwala, Hunaid B; Luebke, David R.; Damodaran, Krishnan

2013-04-24T23:59:59.000Z

284

Free Radical Polymerization of Styrene and Methyl Methacrylate in Various Room Temperature Ionic Liquids  

SciTech Connect (OSTI)

Conventional free radical polymerization of styrene and methyl methacrylate was carried out in various room temperature ionic liquids (RTILs). The RTILs used in this research encompass a wide range of cations and anions. Typical cations include imidazolium, phosphonium, pyridinium, and pyrrolidinium; typical anions include amide, borate, chloride, imide, phosphate, and phosphinate. Reactions are faster and polymers obtained usually have higher molecular weights when compared to polymerizations carried out in volatile organic solvents under the same conditions. This shows that rapid rates of polymerization and high molecular weights are general features of conventional radical polymerizations in RTILs. Attempts to correlate the polarities and viscosities of the RTILs with the polymerization behavior fail to yield discernible trends.

Zhang, Hongwei [University of Tennessee, Knoxville (UTK); Hong, Kunlun [ORNL; Mays, Jimmy [ORNL

2005-01-01T23:59:59.000Z

285

Transparent Poly(methyl methacrylate)/Single-Walled Carbon Nanotube (PMMA/SWNT) Composite Films with Increased  

E-Print Network [OSTI]

Transparent Poly(methyl methacrylate)/Single-Walled Carbon Nanotube (PMMA/SWNT) Composite Films to conventional polymer composites due to the stronger interac- tions between polymer and filler phases. Carbon and fast-growing class of materials with nanosized filler domains finely dispersed in a polymer matrix.[1

Harmon, Julie P.

286

MODELING FRETTING-CORROSION WEAR OF 316L SS AGAINST POLY(METHYL METHACRYLATE) WITH THE POINT DEFECT  

E-Print Network [OSTI]

1 MODELING FRETTING-CORROSION WEAR OF 316L SS AGAINST POLY(METHYL METHACRYLATE) WITH THE POINT; ddm2@psu.edu c Center of Research Excellence in Corrosion Research Institute King Fahd University at investigating experimentally fretting corrosion, that is, corrosion induced by friction of AISI 316L SS against

Boyer, Edmond

287

270 | VOL.9 NO.3 | MARCH2012 | nature methods Key requirements for methylation analysis of large sample sizes  

E-Print Network [OSTI]

). This method eliminates five steps from Illumina's library- construction protocol such that multiplexed and sequenced all at once in a single Illumina HiSeq flowcell. Additionally we designed barcodes to process 384 an analysis pipeline for read mapping and methylation quantification, called bisReadMapper (Supplementary Fig

Cai, Long

288

Understanding mercury demethylation is the key to decrease the high environmental levels of the neurotoxin methyl-Hg in lakes.  

E-Print Network [OSTI]

dynamics of MeHg is the net result of three major processes: 1) formation by Hg methylation 2) degradation (demethylation) and Hg2+ reduction to Hg0 and evasion to the atmosphere. The major process of MeHg degradation is driven by UV light in surface waters. Although biotic demethylation processes are less well understood

Uppsala Universitet

289

Mercury Methylation at Mercury Mines In The Humboldt River Basin, Nevada, USA  

SciTech Connect (OSTI)

Total Hg and methylmercury concentrations were measured in mine-waste calcines (retorted ore), sediment, and water samples collected in and around abandoned mercury mines in western Nevada to evaluate Hg methylation at the mines and in the Humboldt River basin. Mine-waste calcines contain total Hg concentrations as high as 14 000?g/g. Stream-sediment samples collected within 1 km of the mercury mines contain total Hg concentrations as high as 170?g/g, whereas stream sediments collected>5 km from the mines, and those collected from the Humboldt River and regional baseline sites, contain total Hg concentrations<0.5?g/g. Similarly, methylmercury concentrations in mine-waste calcines are locally as high as 96 ng/g, but methylmercury contents in stream-sediments collected downstream from the mines and from the Humboldt River are lower, ranging from<0.05 to 0.95 ng/g. Stream-water samples collected below two mines studied contain total Hg concentrations ranging from 6 to 2000 ng/L, whereas total Hg in Humboldt River water was generally lower ranging from 2.1 to 9.0 ng/L. Methylmercury concentrations in the Humboldt River water were the lowest in this study (<0.02-0.27 ng/L). Although total Hg and methylmercury concentrations are locally high in mine-waste calcines, there is significant dilution of Hg and lower Hg methylation down gradient from the mines, especially in the sediments and water collected from the Humboldt River, which is> 8 km from any mercury mines. Our data indicate little transference of Hg and methylmercury from the sediment to the water column due to the lack of mine runoff in this desert climate.

Gray, John E. (U.S. Geological Survey); Crock, James G. (U.S. Geological Survey); Lasorsa, Brenda K. (BATTELLE (PACIFIC NW LAB))

2002-12-01T23:59:59.000Z

290

Insights antifibrotic mechanism of methyl palmitate: Impact on nuclear factor kappa B and proinflammatory cytokines  

SciTech Connect (OSTI)

Fibrosis accompanies most chronic liver disorders and is a major factor contributing to hepatic failure. Therefore, the need for an effective treatment is evident. The present study was designed to assess the potential antifibrotic effect of MP and whether MP can attenuate the severity of oxidative stress and inflammatory response in chronic liver injury. Male albino rats were treated with either CCl{sub 4} (1 ml/kg, twice a week) and/or MP (300 mg/kg, three times a week) for six weeks. CCl{sub 4}-intoxication significantly increased liver weight, serum aminotransferases, total cholesterol and triglycerides while decreased albumin level and these effects were prevented by co-treatment with MP. As indicators of oxidative stress, CCl{sub 4}-intoxication caused significant glutathione depletion and lipid peroxidation while MP co-treatment preserved them within normal values. As markers of fibrosis, hydroxyproline content and ?-SMA expression increased markedly in the CCl{sub 4} group and MP prevented these alterations. Histopathological examination by both light and electron microscope further confirmed the protective efficacy of MP. To elucidate the antifibrotic mechanisms of MP, the expression of NF-?B, iNOS and COX-2 and the tissue levels of TNF-? and nitric oxide were assessed; CCl{sub 4} increased the expression of NF-?B and all downstream inflammatory cascade while MP co-treatment inhibited them. Collectively these findings indicate that MP possesses a potent antifibrotic effect which may be partly a consequence of its antioxidant and anti-inflammatory properties. -- Highlights: ? Methyl palmitate is free fatty acid methyl ester. ? It possesses a strong antifibrotic effect. ? It inhibits NF-?B and the consequent proinflammatory and oxidative stress response.

Mantawy, Eman M.; Tadros, Mariane G. [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt)] [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt); Awad, Azza S. [Department of Pharmacology and Toxicology, Faulty of Pharmacy, Al-Azhar University, Cairo (Egypt)] [Department of Pharmacology and Toxicology, Faulty of Pharmacy, Al-Azhar University, Cairo (Egypt); Hassan, Dina A.A. [Department of Histology, Faculty of Medicine, Al-Azhar University, Cairo (Egypt)] [Department of Histology, Faculty of Medicine, Al-Azhar University, Cairo (Egypt); El-Demerdash, Ebtehal, E-mail: ebtehal_dm@yahoo.com [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt)] [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt)

2012-01-01T23:59:59.000Z

291

Composition and method for encapsulating photovoltaic devices  

DOE Patents [OSTI]

A composition and method for encapsulating a photovoltaic device which minimizes discoloration of the encapsulant. The composition includes an ethylene-vinyl acetate encapsulant, a curing agent, an optional ultraviolet light stabilizer, and/or an optional antioxidant. The curing agent is preferably 1,1-di-(t-butylperoxy)-3,3,5-trimethylcyclohexane; the ultraviolet light stabilizer is bis-(N-octyloxy-tetramethyl) piperidinyl sebacate and the antioxidant is selected from the group consisting of tris (2,4-di-tert-butylphenyl) phosphite, tetrakis methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) methane, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, and 2,2'-ethylidene bis(4,6-di-t-butylphenyl) fluorophosponite. The composition is applied to a solar cell then cured. The cured product contains a minimal concentration of curing-generated chromophores and resists UV-induced degradation.

Pern, Fu-Jann (Golden, CO)

2000-01-01T23:59:59.000Z

292

Methylated trivalent arsenicals are potent inhibitors of glucose stimulated insulin secretion by murine pancreatic islets  

SciTech Connect (OSTI)

Epidemiologic evidence has linked chronic exposure to inorganic arsenic (iAs) with an increased prevalence of diabetes mellitus. Laboratory studies have identified several mechanisms by which iAs can impair glucose homeostasis. We have previously shown that micromolar concentrations of arsenite (iAs{sup III}) or its methylated trivalent metabolites, methylarsonite (MAs{sup III}) and dimethylarsinite (DMAs{sup III}), inhibit the insulin-activated signal transduction pathway, resulting in insulin resistance in adipocytes. Our present study examined effects of the trivalent arsenicals on insulin secretion by intact pancreatic islets isolated from C57BL/6 mice. We found that 48-hour exposures to low subtoxic concentrations of iAs{sup III}, MAs{sup III} or DMAs{sup III} inhibited glucose-stimulated insulin secretion (GSIS), but not basal insulin secretion. MAs{sup III} and DMAs{sup III} were more potent than iAs{sup III} as GSIS inhibitors with estimated IC{sub 50} ? 0.1 ?M. The exposures had little or no effects on insulin content of the islets or on insulin expression, suggesting that trivalent arsenicals interfere with mechanisms regulating packaging of the insulin transport vesicles or with translocation of these vesicles to the plasma membrane. Notably, the inhibition of GSIS by iAs{sup III}, MAs{sup III} or DMAs{sup III} could be reversed by a 24-hour incubation of the islets in arsenic-free medium. These results suggest that the insulin producing pancreatic ?-cells are among the targets for iAs exposure and that the inhibition of GSIS by low concentrations of the methylated metabolites of iAs may be the key mechanism of iAs-induced diabetes. - Highlights: ? Trivalent arsenicals inhibit glucose stimulated insulin secretion by pancreatic islets. ? MAs{sup III} and DMAs{sup III} are more potent inhibitors than arsenite with IC{sub 50} ? 0.1 ?M. ? The arsenicals have little or no effects on insulin expression in pancreatic islets. ? The inhibition of insulin secretion by arsenite, MAs{sup III} or DMAs{sup III} is reversible. ? Thus, pancreatic ?-cells may be primary targets for chronic exposure to arsenic.

Douillet, Christelle [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Currier, Jenna [Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Saunders, Jesse [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Bodnar, Wanda M. [Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7431 (United States); Matoušek, Tomáš [Institute of Analytical Chemistry of the ASCR, v.v.i., Veve?í 97, 602 00 Brno (Czech Republic); Stýblo, Miroslav, E-mail: styblo@med.unc.edu [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States)

2013-02-15T23:59:59.000Z

293

Synthesis and properties of poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid)/PbS hybrid composite  

SciTech Connect (OSTI)

The synthesis of a new hybrid composite based on PbS nanoparticles and poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid) [P(MMA-AMPSA)] copolymer is reported. The chemical synthesis consists in two steps: (i) a surfactant-free emulsion copolymerization between methyl methacrylate and 2-acrylamido-2-methylpropane sulfonic acid and (ii) the generation of PbS particles in the presence of the P(MMA-AMPSA) latex, from the reaction between lead nitrate and thiourea. The composite was studied by scanning electron microscopy (SEM), X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The microstructure observed using SEM proves that the PbS nanoparticles are well dispersed in the copolymer matrix. The X-ray diffraction measurements demonstrate that the PbS nanoparticles have a cubic rock salt structure. It was also found that the inorganic semiconductor nanoparticles improve the thermal stability of the copolymer matrix.

Preda, N., E-mail: nicol@infim.ro [National Institute of Materials Physics, Multifunctional Materials and Structures Laboratory, P.O. Box MG-7, 77125 Bucharest (Romania); Rusen, E. [University Politehnica Bucharest, Department of Polymer Science, Calea Victoriei No. 71101, Bucharest (Romania)] [University Politehnica Bucharest, Department of Polymer Science, Calea Victoriei No. 71101, Bucharest (Romania); Musuc, A. [Institute of Physical Chemistry, 060021 Bucharest (Romania)] [Institute of Physical Chemistry, 060021 Bucharest (Romania); Enculescu, M.; Matei, E. [National Institute of Materials Physics, Multifunctional Materials and Structures Laboratory, P.O. Box MG-7, 77125 Bucharest (Romania)] [National Institute of Materials Physics, Multifunctional Materials and Structures Laboratory, P.O. Box MG-7, 77125 Bucharest (Romania); Marculescu, B. [University Politehnica Bucharest, Department of Polymer Science, Calea Victoriei No. 71101, Bucharest (Romania)] [University Politehnica Bucharest, Department of Polymer Science, Calea Victoriei No. 71101, Bucharest (Romania); Fruth, V. [Institute of Physical Chemistry, 060021 Bucharest (Romania)] [Institute of Physical Chemistry, 060021 Bucharest (Romania); Enculescu, I. [National Institute of Materials Physics, Multifunctional Materials and Structures Laboratory, P.O. Box MG-7, 77125 Bucharest (Romania)] [National Institute of Materials Physics, Multifunctional Materials and Structures Laboratory, P.O. Box MG-7, 77125 Bucharest (Romania)

2010-08-15T23:59:59.000Z

294

Anti-inflammatory activity of methyl palmitate and ethyl palmitate in different experimental rat models  

SciTech Connect (OSTI)

Methyl palmitate (MP) and ethyl palmitate (EP) are naturally occurring fatty acid esters reported as inflammatory cell inhibitors. In the current study, the potential anti-inflammatory activity of MP and EP was evaluated in different experimental rat models. Results showed that MP and EP caused reduction of carrageenan-induced rat paw edema in addition to diminishing prostaglandin E2 (PGE2) level in the inflammatory exudates. In lipopolysaccharide (LPS)-induced endotoxemia in rats, MP and EP reduced plasma levels of tumor necrosis factor-? (TNF-?) and interleukin-6 (IL-6). MP and EP decreased NF-?B expression in liver and lung tissues and ameliorated histopathological changes caused by LPS. Topical application of MP and EP reduced ear edema induced by croton oil in rats. In the same animal model, MP and EP reduced neutrophil infiltration, as indicated by decreased myeloperoxidase (MPO) activity. In conclusion, this study demonstrates the effectiveness of MP and EP in combating inflammation in several experimental models. -- Highlights: ? Efficacy of MP and EP in combating inflammation was displayed in several models. ? MP and EP reduced carrageenan-induced rat paw edema and prostaglandin E2 level. ? MP and EP decreased TNF-? and IL-6 levels in experimental endotoxemia. ? MP and EP reduced NF-?B expression and histological changes in rat liver and lung. ? MP and EP reduced croton oil-induced ear edema and neutrophil infiltration.

Saeed, Noha M. [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt)] [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt); El-Demerdash, Ebtehal [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt)] [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt); Abdel-Rahman, Hanaa M. [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt)] [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt); Algandaby, Mardi M. [Department of Biology (Botany), Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia)] [Department of Biology (Botany), Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Al-Abbasi, Fahad A. [Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia)] [Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Abdel-Naim, Ashraf B., E-mail: abnaim@pharma.asu.edu.eg [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt)

2012-10-01T23:59:59.000Z

295

Methyl viologen mediated oxidation-reduction across dihexadecylphosphate vesicles involves transmembrane diffusion  

SciTech Connect (OSTI)

Numerous reports have appeared describing oxidation-reduction across bilayer membranes. Mechanisms proposed for specific systems include the following: (i) electron tunneling across the hydrocarbon barrier between interfacially bound redox partners, (ii) molecular diffusion of bound redox components across the barrier, and (iii) formation of barrier-penetrating aggregates, or electron-conducting channels, across the bilayer. Nonetheless, the actual reaction mechanisms remain obscure due to the general unavailability of transverse diffusion rates, possible loss of compartmentation of reactants, particularly in photochemical systems, and the ambiguities inherent in deducing reaction mechanisms from rate data, which form the primary evidence in most systems studied. The reactions of dihexadecylphosphate (DHP) vesicle-bound methyl viologen (MV/sup 2 +/) describes in this report are unique in allowing deduction of molecular details of a transmembrane redox event from the product composition and microphase distribution. Specifically, they have found that MV/sup 2 +/ bound at the outer vesicle interface mediates reduction of inner-localized MV/sup 2 +/ by dithionite ion in bulk solution in a manner that requires comigration of MV/sup +/ with the electron transferred across the membrane barrier.

Patterson, B.C.; Thompson, D.H.; Hurst, J.K.

1988-05-25T23:59:59.000Z

296

Durability of Poly(Methyl Methacrylate) Lenses Used in Concentrating Photovoltaic Modules: Preprint  

SciTech Connect (OSTI)

Concentrating photovoltaic (CPV) technology has recently gained interest based on their expected low levelized cost of electricity, high efficiency, and scalability. Many CPV systems use Fresnel lenses made of poly(methyl methacrylate)(PMMA) to obtain a high optical flux density. The optical and mechanical durability of such components, however, are not well established relative to the desired service life of 30 years. Specific reliability issues may include: reduced optical transmittance, discoloration, hazing, surface erosion, embrittlement, crack growth, physical aging, shape setting (warpage), and soiling. The initial results for contemporary lens- and material-specimens aged cumulatively to 6 months are presented. The study here uses an environmental chamber equipped with a xenon-arc lamp to age specimens at least 8x the nominal field rate. A broad range in the affected characteristics (including optical transmittance, yellowness index, mass loss, and contact angle) has been observed to date, depending on the formulation of PMMA used. The most affected specimens are further examined in terms of their visual appearance, surface roughness (examined via atomic force microscopy), and molecular structure (via Fourier transform infrared spectroscopy).

Miller, D. C.; Gedvilas, L. M.; To, B.; Kennedy, C. E.; Kurtz, S. R.

2010-08-01T23:59:59.000Z

297

Association between body mass index and arsenic methylation efficiency in adult women from southwest U.S. and northwest Mexico  

SciTech Connect (OSTI)

Human arsenic methylation efficiency has been consistently associated with arsenic-induced disease risk. Interindividual variation in arsenic methylation profiles is commonly observed in exposed populations, and great effort has been put into the study of potential determinants of this variability. Among the factors that have been evaluated, body mass index (BMI) has not been consistently associated with arsenic methylation efficiency; however, an underrepresentation of the upper BMI distribution was commonly observed in these studies. This study investigated potential factors contributing to variations in the metabolism of arsenic, with specific interest in the effect of BMI where more than half of the population was overweight or obese. We studied 624 adult women exposed to arsenic in drinking water from three independent populations. Multivariate regression models showed that higher BMI, arsenic (+ 3 oxidation state) methyltransferase (AS3MT) genetic variant 7388, and higher total urinary arsenic were significantly associated with low percentage of urinary arsenic excreted as monomethylarsonic acid (%uMMA) or high ratio between urinary dimethylarsinic acid and uMMA (uDMA/uMMA), while AS3MT genetic variant M287T was associated with high %uMMA and low uDMA/uMMA. The association between BMI and arsenic methylation efficiency was also evident in each of the three populations when studied separately. This strong association observed between high BMI and low %uMMA and high uDMA/uMMA underscores the importance of BMI as a potential arsenic-associated disease risk factor, and should be carefully considered in future studies associating human arsenic metabolism and toxicity.

Gomez-Rubio, Paulina [Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ (United States); Roberge, Jason; Arendell, Leslie; Harris, Robin B.; O'Rourke, Mary K.; Chen, Zhao [Division of Epidemiology and Biostatistics, College of Public Health, University of Arizona, Tucson, AZ (United States); Cantu-Soto, Ernesto; Meza-Montenegro, Maria M. [Department of Environmental Sciences, Instituto Tecnologico de Sonora, Ciudad Obregon, Sonora (Mexico); Billheimer, Dean [Department of Agricultural and Biosystems Engineering, University of Arizona, Tucson, AZ (United States); Lu Zhenqiang [Arizona Statistical Consulting Laboratory, University of Arizona, Tucson, AZ (United States); Klimecki, Walter T., E-mail: klimecki@pharmacy.arizona.edu [Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ (United States)

2011-04-15T23:59:59.000Z

298

Hydrogenolysis of methyl formate over copper on silica. I. Study of surface species by in situ infrared spectroscopy  

SciTech Connect (OSTI)

The hydrogenolysis of methyl formate to methanol over silica-supported copper has been studied using in situ infrared spectroscopy coupled with simultaneous determination of rate. Under flow reaction conditions two forms of adsorbed methyl formate exist. One has a carbonyl absorption at 1726 cm/sup -1/ and is bound to the support by the hydrogen bonding with a heat of adsorption of 65 kJ mol/sup -1/. The second absorbs at 1666 cm/sup -1/ and is bound to copper with an approximate heat of adsorption of 140 kJ mol/sup -1/. At 457 K the hydrogenolysis rate is directly proportional to the band intensity of the latter and hence it, or another species in equilibrium with it, is involved in the rate-determining step. Adsorption of CO from CO/H/sub 2/ mixtures gives rise to a single infrared band at 2117 cm/sup -1/, the corresponding heat of adsorption being 60 kJ mol/sup -1/. Competitive measurements under hydrogenolysis conditions show that methyl formate will partially displace adsorbed CO and not vice versa. Nonetheless CO does reversibly inhibit the rate and this is attributed to its adsorption displacing hydrogen from the surface. The lower concentration of surface hydrogen also reduces the rate of hydrogenation of a formaldehyde intermediate leading to its deposition as a polymer as revealed by infrared bands at 1483 and 1375 cm/sup -1/. The same polymer accretes more rapidly during the reverse methanol to methyl formate reaction for which CO is a substantial by-product and hydrogen pressures are much lower than used for hydrogenolysis. Continuous deactivation of the catalyst is then observed.

Monti, D.M.; Cant, N.W.; Trimm, D.L.; Wainwright, M.S.

1986-07-01T23:59:59.000Z

299

Isobaric vapor-liquid equilibria in the systems methyl 1,1-dimethylethyl ether + hexane and + heptane  

SciTech Connect (OSTI)

The vapor-liquid equilibrium at 94 kPa has been determined for the binary systems of methyl 1,1-dimethylethyl ether (MTBE) with hexane and with heptane. Both systems deviate slightly from ideal behavior, can be described as regular solutions, and do not present an azeotrope. The activity coefficients and boiling point of the solutions were correlated with its composition by the Redlich-Kister, Wohl, Wilson, UNIQUAC, NRTL, and Wisniak-Tamir equations.

Wisniak, J.; Magen, E.; Shachar, M.; Zeroni, I.; Segura, H. [Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel). Dept. of Chemical Engineering] [Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel). Dept. of Chemical Engineering; Reich, R. [Univ. de Concepcion (Chile). Dept. of Chemical Engineering] [Univ. de Concepcion (Chile). Dept. of Chemical Engineering

1997-03-01T23:59:59.000Z

300

Z .The Science of the Total Environment 261 2000 91 98 Mercury methylation along a lake forest transect in  

E-Print Network [OSTI]

and acidified controls 1 3 g dry wt. were slurried with local water and incubated in the dark at 25 28 C for y1 those heavily Z . Z y2 .colonized with periphyton 3.4 5.4% . Methylation in surface or near-bottom water: jeanrdg@biof.ufrj.br J.R. Guimaraes .~ 0048-9697r00r$ - see front matter 2000 Elsevier Science B.V. All

Long, Bernard

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Evaluating the Identity and Diiron Core Transformations of a (?-Oxo)diiron(III) Complex Supported by Electron-Rich Tris(pyridyl-2-methyl)amine Ligands  

E-Print Network [OSTI]

The composition of a (?-oxo)diiron(III) complex coordinated by tris[(3,5-dimethyl-4-methoxy)pyridyl-2-methyl]amine (R[subscript 3]TPA) ligands was investigated. Characterization using a variety of spectroscopic methods and ...

Do, Loi H.

302

Oxidation Kinetics of Pure and Blended Methyl Octanoate/n-Nonane/Methylcyclohexane: Measurements and Modeling of OH*/CH* Chemiluminescence, Ignition Delay Times and Laminar Flame Speeds  

E-Print Network [OSTI]

fuels at 1.5 atm indicated the following ignition delay time order, from shortest to longest: methyl octanoate atm (nominal) the order remained, in general, consistent. Under fuel-lean conditions, ignition...

Rotavera, Brandon Michael

2012-07-16T23:59:59.000Z

303

Structural and biochemical insights into 2?-O-methylation at the 3?-terminal nucleotide of RNA by Hen1  

SciTech Connect (OSTI)

Small RNAs of {approx}20-30 nt have diverse and important biological roles in eukaryotic organisms. After being generated by Dicer or Piwi proteins, all small RNAs in plants and a subset of small RNAs in animals are further modified at their 3'-terminal nucleotides via 2'-O-methylation, carried out by the S-adenosylmethionine-dependent methyltransferase (MTase) Hen1. Methylation at the 3' terminus is vital for biological functions of these small RNAs. Here, we report four crystal structures of the MTase domain of a bacterial homolog of Hen1 from Clostridium thermocellum and Anabaena variabilis, which are enzymatically indistinguishable from the eukaryotic Hen1 in their ability to methylate small single-stranded RNAs. The structures reveal that, in addition to the core fold of the MTase domain shared by other RNA and DNA MTases, the MTase domain of Hen1 possesses a motif and a domain that are highly conserved and are unique to Hen1. The unique motif and domain are likely to be involved in RNA substrate recognition and catalysis. The structures allowed us to construct a docking model of an RNA substrate bound to the MTase domain of bacterial Hen1, which is likely similar to that of the eukaryotic counterpart. The model, supported by mutational studies, provides insight into RNA substrate specificity and catalytic mechanism of Hen1.

Chan, Chio Mui; Zhou, Chun; Brunzelle, Joseph S.; Huang, Raven H.; (UIUC); (NWU)

2010-01-28T23:59:59.000Z

304

Unexpected effects of gene deletion on mercury interactions with the methylation-deficient mutant hgcAB  

SciTech Connect (OSTI)

The hgcA and hgcB gene pair is essential for mercury (Hg) methylation by certain anaerobic bacteria,1 but little is known about how deletion of hgcAB affects cell surface interactions and intracellular uptake of Hg. Here, we compare hgcAB mutants with the wild-type (WT) strains of both Geobacter sulfurreducens PCA and Desulfovibrio desulfuricans ND132 and observe differences in Hg redox transformations, adsorption, and uptake in laboratory incubation studies. In both strains, deletion of hgcAB increased the reduction of Hg(II) but decreased the oxidation of Hg(0) under anaerobic conditions. The measured cellular thiol content in hgcAB mutants was lower than the WT, accounting for decreased adsorption and uptake of Hg. Despite the lack of methylation activity, Hg uptake by the hgcAB continued, albeit at a slower rate than the WT. These findings demonstrate that deletion of the hgcAB gene not only eliminates Hg methylation but also alters cell physiology, resulting in changes to Hg redox reactions, sorption, and uptake by cells.

Lin, Hui [ORNL] [ORNL; Hurt, Jr., Richard Ashley [ORNL; Johs, Alexander [ORNL] [ORNL; Parks, Jerry M [ORNL] [ORNL; Morrell-Falvey, Jennifer L [ORNL] [ORNL; Liang, Liyuan [ORNL] [ORNL; Elias, Dwayne A [ORNL] [ORNL; Gu, Baohua [ORNL] [ORNL

2014-01-01T23:59:59.000Z

305

Nonpremixed ignition, laminar flame propagation, and mechanism reduction of n-butanol, iso-butanol, and methyl butanoate  

SciTech Connect (OSTI)

The non-premixed ignition temperature of n-butanol (CH{sub 3}CH{sub 2}CH{sub 2}CH{sub 2}OH), iso-butanol ((CH{sub 3}){sub 2}CHCH{sub 2}OH) and methyl butanoate (CH{sub 3}CH{sub 2}CH{sub 2}COOCH{sub 3}) was measured in a liquid pool assembly by heated oxidizer in a stagnation flow for system pressures of 1 and 3 atm. In addition, the stretch-corrected laminar flame speeds of mixtures of air–n-butanol/iso-butanol/methyl butanoate were determined from the outwardly propagating spherical flame at initial pressures of up to 2 atm, for an extensive range of equivalence ratio. The ignition temperature and laminar flame speeds of n-butanol and methyl butanoate were computationally simulated with three recently developed kinetic mechanisms in the literature. Dominant reaction pathways to ignition and flame propagation were identified and discussed through a chemical explosive mode analysis (CEMA) and sensitivity analysis. The detailed models were further reduced through a series of systematic strategies. The reduced mechanisms provided excellent agreement in both homogeneous and diffusive combustion environments and greatly improved the computation efficiency.

Lu, Wei; Kelley, A. P.; Law, C. K.

2011-01-01T23:59:59.000Z

306

Vapor-liquid equilibrium data at 298. 15 K for binary systems containing methyl acetate or methanol with 2-methoxyethanol or 2-ethoxyethanol  

SciTech Connect (OSTI)

Isothermal vapor-liquid equilibria were measured at 298.15 K for the systems containing methyl acetate or methanol with 2-methoxyethanol or 2-ethoxyethanol. Mixtures containing methanol show a behavior close to ideal, while those containing methyl acetate exhibit positive deviations from ideality and satisfy the Redlich-Kister thermodynamic consistency test. The liquid-phase activity coefficients were fitted by using the van Laar, Wilson, NRTL, and NRTL-m (a modified NRTL equation) equations.

Martin, M.C.; Cocero, M.J.; Mato, F.B. (Univ. de Valladolid (Spain))

1994-07-01T23:59:59.000Z

307

Selecting activated carbon for water and wastewater treatability studies  

SciTech Connect (OSTI)

A series of follow-up investigations were performed to produce data for improving the four-indicator carbon selection method that we developed to identify high-potential activated carbons effective for removing specific organic water pollutants. The carbon's pore structure and surface chemistry are dependent on the raw material and the activation process. Coconut carbons have relatively more small pores than large pores; coal and apricot nutshell/walnut shell fruit carbons have the desirable pore structures for removing adsorbates of all sizes. Chemical activation, excessive activation, and/or thermal reactivation enlarge small pores, resulting in reduced phenol number and higher tannic acid number. Activated carbon's phenol, iodine, methylene blue, and tannic acid numbers are convenient indicators of its surface area and pore volume of pore diameters < 10, 10-15, 15-28, and > 28 angstrom, respectively. The phenol number of a carbon is also a good indicator of its surface acidity of oxygen-containing organic functional groups that affect the adsorptive capacity for aromatic and other small polar organics. The tannic acid number is an indicator of carbon's capacity for large, high-molecular-weight natural organic precursors of disinfection by-products in water treatment. The experimental results for removing nitrobenzene, methyl-tert-butyl ether, 4,4-bisphenol, humic acid, and the organic constituents of a biologically treated coking-plant effluent have demonstrated the effectiveness of this capacity-indicator-based method of carbon selection.

Zhang, W.; Chang, Q.G.; Liu, W.D.; Li, B.J.; Jiang, W.X.; Fu, L.J.; Ying, W.C. [East China University of Chemical Technology, Shanghai (China)

2007-10-15T23:59:59.000Z

308

Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 6, January 1, 1992--March 31, 1992  

SciTech Connect (OSTI)

The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. (2) Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. (3) Addition of methanol to slurry phase FT synthesis making iso-olefins. During the sixth quarter we completed the construction of the slurry bubble column reactor (SBCR), conducted initial shake-down experiments in a cold-flow mode, and finalized the selection process of the acid catalysts for conversion of syngas-produced alcohols and isobutylene to MTBE (scheme 2). Tasks 3, 4, and 5 are awaiting complete implementation of the SBCR system.

Marcelin, G.

1992-06-24T23:59:59.000Z

309

Fast photoreactions of ethanol and MTBE on tropospheric metal oxide particles  

SciTech Connect (OSTI)

Ethanol (EtOH) and tert-Butyl methyl ether (MTBE) are both finding increased use as oxygenated additives to fuels. However, the environmental fate in the troposphere of these species is unclear when they escape as fugitive emissions. In several locations there are reports of human illness in response to MTBE in particular. Volatile organic compounds (VOC`s) such as these are generally thought to react by a variety of homogeneous free-radical mechanisms, usually beginning with attack by OH radical. However, we show by laboratory kinetic studies that the heterogeneous photoreaction on solid suspended metal-oxide particulates such as fly ash proceeds with a comparable rate, especially in urban environments. EtOH reacts to form acetaldehyde, and EtOH forms isobutene, methanol, and formaldehyde. Our work appears to be the first-ever demonstration that VOC`s can react as fast by a heterogeneous mechanism as by a homogeneous one in the atmosphere. Experiments by various optical and kinetic techniques show that the active phases in fly ash are Fe oxides, which are fairly abundant in other atmospheric particulates as well.

Idriss, H.; Seebauer, E.G. [Univ. of Illinois, Urbana, IL (United States)

1995-12-31T23:59:59.000Z

310

High-temperature ignition of propane with MTBE as an additive: Shock-tube experiments and modeling  

SciTech Connect (OSTI)

Ignition of propane has been studied in a shock tube and by computational modeling to determine the effect of methyl tert-butyl ether (MTBE) as a fuel additive. MTBE and isobutene were added in amounts up to 25% of the fuel to propane-oxygen-argon mixtures in shock-tube experiments covering a range of temperatures between 1450 and 1800 K. Ignition delays were measured from chemiluminescence at 432 nm due to excited CH radicals. The temperature dependence of the ignition rates was analyzed to yield Arrhenius parameters of E{sub a}{approximately}40 kcal/mol and log (A){approximately} 9.0 sec{sup {minus}1} for the overall reaction. Reactions involving MTBE and its decomposition products were combined with an established propane mechanism in a numerical model to describe the kinetic interaction of this additive with a typical hydrocarbon fuel. The experiments and the kinetic model both show that MTBE and isobutene retard propane ignition with nearly equal efficiency. The kinetic model demonstrates that isobutene kinetics are responsible for inhibition by both MTBE and isobutene, and the specific elementary reactions which produce this behavior are identified.

Gray, J.A. (Sandia National Labs., Livermore, CA (United States)); Westbrook, C.K. (Lawrence Livermore National Lab., CA (United States))

1991-01-01T23:59:59.000Z

311

Meeting the challenge of MTBE biodegradation  

SciTech Connect (OSTI)

Oxygenated and reformulated gasolines have been developed in response to air pollution control regulations targeted at reducing carbon monoxide emissions and photochemical air pollution. The 1990 Clean Air Act Amendments required the addition of fuel oxygenates to gasoline in areas where the level of carbon monoxide exceeded national ambient air quality standards. In the South Coast Air Basin gasoline containing oxygenated compounds has been in use since the late 1980`s. One oxygenated fuel additive most often selected by producers to meet the requirements is methyl tert-butyl ether (MTBE). However, large production numbers associated with MTBE production, combined with the compound`s high water solubility, chemical stability, and toxicity, make it a potentially important groundwater pollutant. The County Sanitation District of Los Angeles, Joint Water Pollution Control Plant in Carson, California is one of the few wastewater treatment plants in the nation that receives refinery wastewater discharge. It has operated several pilot-scale compost-based biofilters for control of various volatile organic contaminants throughout the plant since a 1991 joint study with the University of California, Davis. After one year of operation, one of the biofilters spontaneously developed the ability to degrade MTBE. The paper describes the collaborative efforts to determine the feasibility of transferring the degrading microbial population from the solid to liquid phase, without loss of activity, and to determine some of the environmental requirements necessary for survival of the microbial culture.

Eweis, J.B.; Chang, D.P.Y.; Schroeder, E.D.; Scow, K.M. [Univ. of California, Davis, CA (United States); Morton, R.L.; Caballero, R.C. [Los Angeles County Sanitation Districts, Carson, CA (United States). Joint Water Pollution Control Plant

1997-12-31T23:59:59.000Z

312

Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 7, April 1, 1992--June 30, 1992  

SciTech Connect (OSTI)

The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: addition of i-butylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch; addition of i-butylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst; and addition of methanol to slurry phase FT synthesis making iso-olefins. During the seventh quarter we continued the shake down experiments for the SBCR and conducted an initial aborted run. We have also re-started experiments on Scheme 1, i.e., the addition of iso-butylene during CO hydrogenation. Using a dual bed arrangement, we have demonstrated the synthesis of MTBE from syngas and iso-butylene.

Marcelin, G.

1992-09-24T23:59:59.000Z

313

Interdisciplinary investigation of subsurface contaminant transport and fate at point-source releases of gasoline containing MTBE  

SciTech Connect (OSTI)

Methyl tert-butyl ether (MTBE) is commonly found at concentrations above the current U.S. Environmental Protection Agency draft lifetime health advisory for drinking water (20 to 200 micrograms per liter) at many point-source gasoline release sites. MTBE is significantly more persistent than benzene, toluene, ethyl-benzene and xylenes (BTEX) in the subsurface. Therefore, evaluation of the implications of its presence in gasoline to monitored natural attenuation and engineered bioremediation alternatives is warranted. An interdisciplinary, field-based investigation of the subsurface transport and fate of MTBE and petroleum hydrocarbons is being conducted by the U.S. Geological Survey (USGS) Toxic Substances Hydrology Program at the site of an underground gasoline storage-tank release near Beaufort, South Carolina. The objective of the investigation is to provide a systematic evaluation of natural attenuation of MTBE compared to BTEX. Results of the field and laboratory studies at this site will be generalized to a broader range of hydrogeochemical conditions through experiments at other sites. Furthermore, newly developed methods of analysis can be applied to sites across the Nation. This investigation of MTBE at point-source release sites is coordinated with investigations of the occurrence of MTBE in shallow ground water, surface water, precipitation, and the atmosphere being conducted by the USGS National Water-Quality Assessment Program.

Buxton, H.T.; Baehr, A.L. [Geological Survey, West Trenton, NJ (United States); Landmeyer, J.E. [Geological Survey, Columbia, SC (United States)] [and others

1997-12-31T23:59:59.000Z

314

High-temperature ignition of propane with MTBE as an additive: Shock-tube experiments and modeling. Revision 1  

SciTech Connect (OSTI)

Ignition of propane has been studied in a shock tube and by computational modeling to determine the effect of methyl tert-butyl ether (MTBE) as a fuel additive. MTBE and isobutene were added to amounts up to 25% of the fuel to propane-oxygen-argon mixtures to shock-tube experiments covering a range of temperatures between 1450 and 1800 K. Ignition delays were measured from chemiluminescence at 432 nm due to excited CH radicals. The temperature dependence of the ignition rates was analyzed to yield Arrhenium parameters of E{sub a}{sup {minus}}40 kcal/mol and log(A) {sup {minus}}9.0 sec{sup {minus}1} for the overall reaction. Reactions involving MTBE and its decomposition products were combined with an established propane mechanism in a numerical model to describe the kinetic interaction of this additive with a typical hydrocarbon fuel. The experiments and the kinetic model both show that MTBE and isobutene retard propane ignition with nearly equal efficiency. The kinetic model demonstrates that isobutene kinetics are responsible for inhibition by both MTBE and isobutene, and the specific elementary reactions which produce this behavior are identified. 19 refs., 1 fig., 3 tabs.

Gray, J.A. [Sandia National Labs., Livermore, CA (United States); Westbrook, C.K. [Lawrence Livermore National Lab., CA (United States)

1991-12-01T23:59:59.000Z

315

Effects of temperature and acidic pre-treatment on Fenton-driven oxidation of MTBE-spent granular activated carbon  

SciTech Connect (OSTI)

The effects of temperature and acidic pretreatment on Fenton-driven chemical oxidation of methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC, derived from bituminous coal) were investigated. Limiting factors in MTBE removal in GAC include the heterogeneous distribution of amended Fe, and slow intraparticle diffusive transport of MTBE and hydrogen peroxide (H{sub 2}O{sub 2}) into the 'reactive zone'. Acid pretreatment of GAC before Fe amendment altered the surface chemistry of the GAC, lowered the pH point of zero charge, and resulted in greater penetration and more uniform distribution of Fe in GAC. This led to a condition where Fe, MTBE, and H{sub 2}O{sub 2} coexisted over a larger volume of the GAC contributing to greater MTBE oxidation and removal. H{sub 2}O{sub 2} reaction and MTBE removal in GAC increased with temperature. Modeling H{sub 2}O{sub 2} transport and reaction in GAC indicated that H{sub 2}O{sub 2} penetration was inversely proportional with temperature and tortuosity, and occurred over a larger fraction of the total volume of small GAC particles (0.3 mm diameter) relative to large particles (1.2 mm diameter). Acidic pretreatment of GAC, Fe-amendment, elevated reaction temperature, and use of small GAC particles are operational parameters that improve Fenton-driven oxidation of MTBE in GAC. 29 refs., 6 figs., 1 tab.

Kan, E.; Huling, S.G. [Robert S. Kerr Environmental Research Center, Ada, OK (United States)

2009-03-01T23:59:59.000Z

316

Synthesis of MTBE during CO hydrogenation: Reaction sites required  

SciTech Connect (OSTI)

Synthesis of methyl tert-butyl ether (MTBE) during carbon monoxide (CO) hydrogenation has been studied with the following reaction schemes: (1) the addition of isobutylene during CO hydrogenation over metal catalysts active for methanol synthesis (Pd/SiO{sub 2} and Li-Pd/SiO{sub 2}) and (2) the addition of isobutylene during CO hydrogenation over a dual bed configuration consisting of Li-Pd/SiO{sub 2} and a zeolite (H-ZSM-5 or HY). The addition of isobutylene during methanol synthesis over the supported Pd catalysts indicated that MTBE cannot be formed on metal sites from a reaction of isobutylene with methanol precursors. However, addition of isobutylene to the syngas feed over a dual bed consisting of a methanol synthesis catalyst and an acid zeolite downstream of the methanol synthesis catalyst showed that MTBE can be synthesized during CO hydrogenation provided acid sites are available. In order to get higher conversions of methanol to MTBE, optimization of the acid catalyst and/or reaction conditions would be required to minimize formation of byproduct hydrocarbons.

Kazi, A.M.; Goodwin, J.G. Jr.; Marcelin, G.; Oukaci, R. [Univ. of Pittsburgh, PA (United States). Dept. of Chemical and Petroleum Engineering

1995-03-01T23:59:59.000Z

317

Intrinsic bioremediation of a BTEX and MTBE plume under mixed aerobic/denitrifying conditions  

SciTech Connect (OSTI)

A shallow Coastal Plain aquifer in rural Sampson Country, North Carolina, has been contaminated with petroleum hydrocarbon from a leaking underground storage tank containing gasoline.An extensive field characterization has been performed to define the horizontal and vertical distribution of soluble gasoline components and indicator parameters. A plume of dissolved methyl tert-butyl ether (MTBE) and the aromatic hydrocarbons benzene, toluene, ethylbenzene, and xylene isomers (BTEX) is present in the aquifer and has migrated over 600 ft from the source area. Background dissolved oxygen concentrations range from 7 to 8 mg/L, and nitrate concentrations range from 5 to 22 mg/L as N due to extensive fertilization of fields surrounding the spill. In the center of the BTEX plume, oxygen concentrations decline to less than 1 mg/L while nitrate concentrations remain high. The total mass flux of MTBE and all BTEX components decline with distance downgradient relative to a conservative tracer (chloride). At the source, the total BTEX concentration exceeds 75 mg/L while 130 ft downgradient, total BTEX concentrations are less than 4.9 mg/L, a 15-fold reduction. Toluene and ethylbenzene decline most rapidly followed by m-p-xylene, o-xylene and finally benzene. Biodegradation of TEX appears to be enhanced by the excess nitrate present in the aquifer while benzene biodegradation appears to be due to strictly aerobic processes.

Borden, R.C.; Daniel, R.A. [North Carolina State Univ., Raleigh, NC (United States). Civil Engineering Dept.

1995-09-01T23:59:59.000Z

318

Falling MTBE demand bursts the methanol bubble  

SciTech Connect (OSTI)

Methanol spot markets in Europe and the US have been hit hard by weakening demand from methyl tert-butyl ether (MTBE) producers. In Europe, spot prices for domestic T2 product have dropped to DM620-DM630/m.t. fob from early-January prices above DM800/m.t. and US spot prices have slipped to $1.05/gal fob from $1.35/gal. While chemical applications for methanol show sustained demand, sharp methanol hikes during 1994 have priced MTBE out of the gasoline-additive market. {open_quotes}We`ve learned an important lesson. We killed [MTBE] applications in the rest of the world,{close_quotes} says one European methanol producer. Even with methanol currently at DM620/m.t., another manufacturer points out, MTBE production costs still total $300/m.t., $30/m.t. more than MTBE spot prices. Since late 1994, Europe`s 3.3-million m.t./year MTBE production has been cut back 30%.

Wiesmann, G.; Cornitius, T.

1995-03-01T23:59:59.000Z

319

Synthesis of octane enhancers during slurry-phase Fischer-Tropsch  

SciTech Connect (OSTI)

The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: addition of i-butylene during the formation of methanol and/or higher alcohols directly from CO and H[sub 2] during slurry-phase Fischer-Tropsch; addition of i-butylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst; and addition of methanol to slurry phase FT synthesis making iso-olefins. During the seventh quarter we continued the shake down experiments for the SBCR and conducted an initial aborted run. We have also re-started experiments on Scheme 1, i.e., the addition of iso-butylene during CO hydrogenation. Using a dual bed arrangement, we have demonstrated the synthesis of MTBE from syngas and iso-butylene.

Marcelin, G.

1992-09-24T23:59:59.000Z

320

High-temperature ignition of propane with MTBE as an additive: Shock-tube experiments and modeling  

SciTech Connect (OSTI)

Ignition of propane has been studied in a shock tube and by computational modeling to determine the effect of methyl tert-butyl ether (MTBE) as a fuel additive. MTBE and isobutene were added in amounts up to 25% of the fuel to propane-oxygen-argon mixtures in shock-tube experiments covering a range of temperatures between 1450 and 1800 K. Ignition delays were measured from chemiluminescence at 432 nm due to excited CH radicals. The temperature dependence of the ignition rates was analyzed to yield Arrhenius parameters of E{sub a}{approximately}40 kcal/mol and log (A){approximately} 9.0 sec{sup {minus}1} for the overall reaction. Reactions involving MTBE and its decomposition products were combined with an established propane mechanism in a numerical model to describe the kinetic interaction of this additive with a typical hydrocarbon fuel. The experiments and the kinetic model both show that MTBE and isobutene retard propane ignition with nearly equal efficiency. The kinetic model demonstrates that isobutene kinetics are responsible for inhibition by both MTBE and isobutene, and the specific elementary reactions which produce this behavior are identified.

Gray, J.A. [Sandia National Labs., Livermore, CA (United States); Westbrook, C.K. [Lawrence Livermore National Lab., CA (United States)

1991-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

High-resolution NMR process analyzer for oxygenates in gasoline  

SciTech Connect (OSTI)

We report a high-resolution 42-MHz[sup 1]HFT-NMR instrument that is suitable for use as a process analyzer and demonstrate its use in the determination of methyl tert-butyl ether (MTBE) in a flowing stream of gasoline. This spectrometer is based on a 55-kg permanent magnet with essentially no fringe field. A spectral resolution of 3 Hz was typically obtained for spinning samples, and this performance was only slightly degraded with flowing samples. We report a procedure for magnet drift compensation using a software procedure rather than a field-frequency lock channel. This procedure allowed signal averaging without loss of resolution. Regulatory changes to be implemented in the near future have created a need for the development of methods for the determination of MTBE and other oxygenates in reformulated gasolines. Existing methods employing gas chromatography are not fast enough for process control of a gasoline blender and suffer from other limitations. This study demonstrates that process analysis NMR is well-suited to the determination of MTBE in a simulated gasoline blender. The detection limit of 0.5 vol % MTBE was obtained with a measurement time of 1 min. The absolute standard deviation of independent determinations was 0.17% when the MTBE concentration was 10%, a nominal value. Preliminary results also suggest that the method may be applicable to gasolines containing mixtures of oxygenate additives as well as the measurement of aromatic and olefinic hydrogens. 33 refs., 9 figs.

Skloss, T.W.; Kim, A.J.; Haw, J.F. (Texas A M Univ., College Station, TX (United States))

1994-02-15T23:59:59.000Z

322

Factors influencing biological treatment of MTBE contaminated ground water  

SciTech Connect (OSTI)

Methyl tert-butyl ether (MTBE) contamination has complicated the remediation of gasoline contaminated sites. Many sites are using biological processes for ground water treatment and would like to apply the same technology to MTBE. However, the efficiency and reliability of MTBE biological treatment is not well documented. The objective of this study was to examine the operational and environmental variables influencing MTBE biotreatment. A fluidized bed reactor was installed at a fuel transfer station and used to treat ground water contaminated with MTBE and gasoline hydrocarbons. A complete set of chemical and operational data was collected during this study and a statistical approach was used to determine what variables were influencing MTBE treatment efficiency. It was found that MTBE treatment was more sensitive to up-set than gasoline hydrocarbon treatment. Events, such as excess iron accumulation, inhibited MTBE treatment, but not hydrocarbon treatment. Multiple regression analysis identified biomass accumulation and temperature as the most important variables controlling the efficiency of MTBE treatment. The influent concentration and loading of hydrocarbons, but not MTBE, also impacted MTBE treatment efficiency. The results of this study suggest guidelines for improving MTBE treatment. Long cell retention times in the reactor are necessary for maintaining MTBE treatment. The onset of nitrification only occurs when long cell retention times have been reached and can be used as an indicator in fixed film reactors that conditions favorable to MTBE treatment exist. Conversely, if the reactor can not nitrify, it is unlikely to have stable MTBE treatment.

Stringfellow, William T.; Hines Jr., Robert D.; Cockrum, Dirk K.; Kilkenny, Scott T.

2001-09-14T23:59:59.000Z

323

MTBE, methanol prices rise  

SciTech Connect (OSTI)

After several months of drifting lower in line with declining autumn gasoline prices, tabs for methyl tert-butyl ether (MTBE) have turned around. There has been no big demand surge, but consumers and traders are beginning to build up inventories in advance of a series of midwinter shutdowns and turnarounds by producers. Spot prices, which dropped as low as 75 cts/gal, have rebounded to 90 cts/gal fob. Eager for a positive glimmer, methanol producers posted a 3-cts/gal increase in contract prices this month. It marks the first upward idea since February. In that time contract prices have dropped 75% from $1.55/gal to 39 cts/gal. A hard winter has hit early in much of the US sending natural gas prices up sharply. At the same time, formaldehyde and acetic acid markets remain firm, and with MTBE rebounding, methanol producers feel entitled to a piece of the action. {open_quotes}I don`t buy into this claim that MTBE demand is up and I don`t think producers can justify even a 3-cts/gal increase,{close_quotes} says one. {open_quotes}There is nothing in the economy to warrant a run-up. Housing starts are weaker, and demand is down at least 80,000 bbl/day with the MTBE shutdown.{close_quotes}

Morris, G.D.L.; Cornitius, T.

1995-12-20T23:59:59.000Z

324

High-temperature ignition of propane with MTBE as an additive: Shock-tube experiments and modeling  

SciTech Connect (OSTI)

Ignition of propane has been studied in a shock tube and by computational modeling to determine the effect of methyl tert-butyl ether (MTBE) as a fuel additive. MTBE and isobutene were added to amounts up to 25% of the fuel to propane-oxygen-argon mixtures to shock-tube experiments covering a range of temperatures between 1450 and 1800 K. Ignition delays were measured from chemiluminescence at 432 nm due to excited CH radicals. The temperature dependence of the ignition rates was analyzed to yield Arrhenium parameters of E{sub a}{sup {minus}}40 kcal/mol and log(A) {sup {minus}}9.0 sec{sup {minus}1} for the overall reaction. Reactions involving MTBE and its decomposition products were combined with an established propane mechanism in a numerical model to describe the kinetic interaction of this additive with a typical hydrocarbon fuel. The experiments and the kinetic model both show that MTBE and isobutene retard propane ignition with nearly equal efficiency. The kinetic model demonstrates that isobutene kinetics are responsible for inhibition by both MTBE and isobutene, and the specific elementary reactions which produce this behavior are identified. 19 refs., 1 fig., 3 tabs.

Gray, J.A. (Sandia National Labs., Livermore, CA (United States)); Westbrook, C.K. (Lawrence Livermore National Lab., CA (United States))

1991-12-01T23:59:59.000Z

325

Heterogeneous models of tubular reactors packed with ion-exchange resins: Simulation of the MTBE synthesis  

SciTech Connect (OSTI)

The study of behavior of fixed-bed reactors using ion-exchange resins as catalysts was carried out by making use of a complete bidimensional heterogeneous model for the reactor, which included the resistances inside the ion-exchange resin particles, considered with a macroreticular structure. The active sites were located inside the gel phase of the resin, represented by microspheres, and on the macropores walls. The overall efficiency of such heterogeneous catalyst particles was defined by the macroeffectiveness and microeffectiveness factors accounting for the process behavior on the macropores and inside the microspheres. The synthesis of methyl tert-butyl ether, MTBE, a liquid-phase reversible exothermic reaction between methanol and isobutene, was considered as a reference case. This system was studied in the temperature range of 313--338 K, and the effect of the thermodynamic equilibrium conditions was examined. The results predicted by the complete heterogeneous model were compared with those obtained with the simple pseudohomogeneous model, which revealed higher hot spots. Moreover, a comparison between bidimensional and unidimensional models was also performed. The orthogonal collocation method was used for the discretization of the differential equations inside the catalyst particles, which were reduced from three (corresponding to the three mass balances for the three compounds, isobutene, methanol, and MTBE) to only one differential equation, by using the concept of the generalized variable.

Quinta Ferreira, R.M.; Almeida-Costa, C.A. [Univ. of Coimbra (Portugal). Dept. of Chemical Engineering; Rodrigues, A.E. [Univ. of Porto (Portugal). Dept. of Chemical Engineering

1996-11-01T23:59:59.000Z

326

Add MTBE unit ahead of alkylation  

SciTech Connect (OSTI)

Approximately three years ago, the people at Diamond Shamrock's Sunray, Texas, refinery recognized a growing demand for high octane super premium unleaded gasoline in their regional marketing area. It was apparent that they would need to change their processing scheme to meet this growing demand. After investigating several options, they decided to install an MTBE (methyl tert-butyl ether) unit upstream of their existing sulfuric acid (H/sub 2/SO/sub 4/) aklylation unit. The new unit would process olefin feed before it entered the alkylation unit. The MTBE unit was expected to improve Diamond Shamrock's gasoline pool in two ways. First, the MTBE would be an additional high octane blending stock for the gasoline pool. Second, the MTBE unit would improve the quality of the olefin stream going to the alkylation unit. Diamond Shamrock brought their MTBE unit onstream in December, 1985. The results of the combined operation exceeded expectations, producing alkylate in excess of 98 RON (Research octane number) and MTBE of 118 RON. These components significantly upgraded the refinery's capability to produce a super premium unleaded gasoline.

Masters, K.R.; Prohaska, E.A.

1988-08-01T23:59:59.000Z

327

Study downplays health concerns  

SciTech Connect (OSTI)

A government-funded study has concluded that reformulated gasoline containing methyl tert-butyl ether (MTBE) does not increase short-term health risks when compared with gasoline that does not contain the additive. The study, performed by the Health Effects Institute (Cambridge, MA), compared data from dozens of animal, human, and epidemiological studies of health effects linked to oxygenates, including MTBE and ethanol, but did not find enough evidence to warrant an immediate reduction in oxygenate use. However, the study did recommend that additional research be conducted on possible health consequences associated with the gasoline additives, including neurotoxic effects, if oxygenates continue to be used long term. Oxygenates have been used in gasoline since 1992, when EPA mandated that several municipalities use MTBE or other oxygenates in reformulated gasoline to reduce carbon monoxide emissions and meet Clean Air Act requirements. Shortly after the program began, residents in areas where the oxygenates were used complained of nausea, headaches, and dizziness. The institute says the study--funded by EPA and the Centers for Disease Control--will be used for a broader review of gasoline oxygenates by the White House Office of Science and Technology Policy.

Stringer, J.

1996-03-13T23:59:59.000Z

328

Characterization of the Cobalamin and Fep Operons in Methylobium petrolphilum PM1  

SciTech Connect (OSTI)

The bacterium Methylobium petroleophilum PM1 is economically important due to its ability to degrade methyl tert-butyl ether (MTBE), a fuel additive. Because PM1 is a representative of all MTBE degraders, it is important to understand the transport pathways critical for the organism to survive in its particular environment. In this study, the cobalamin pathway and select iron transport genes will be characterized to help further understand all metabolic pathways in PM1. PM1 contains a total of four cobalamin operons. A single operon is located on the chromosome. Located on the megaplasmid are two tandem repeats of cob operons and a very close representative of the cob operon located on the chromosome. The fep operon, an iron transport mechanism, lies within the multiple copies of the cob operon. The cob operon and the fep operon appear to be unrelated except for a shared need for the T-on-B-dependent energy transduction complex to assist the operons in moving large molecules across the outer membrane of the cell. A genomic study of the cob and the fep operons with that of phylogenetically related organisms helped to confirm the identity of the cob and fep operons and to represent the pathways. More study of the pathways should be done to find the relationship that positions the two seemingly unrelated cob and fep genes together in what appears to be one operon.

Ewing, J

2005-09-06T23:59:59.000Z

329

Encapsulation and Characterization of Proton-Bound Amine Homodimers in a Water Soluble, Self-Assembled Supramolecular Host  

SciTech Connect (OSTI)

Cyclic amines can be encapsulated in a water-soluble self-assembled supramolecular host upon protonation. The hydrogen bonding ability of the cyclic amines, as well as the reduced degrees of rotational freedom, allows for the formation of proton-bound homodimers inside of the assembly which are otherwise not observable in aqueous solution. The generality of homodimer formation was explored with small N-alkyl aziridines, azetidines, pyrrolidines and piperidines. Proton-bound homodimer formation is observed for N-alkylaziridines (R = methyl, isopropyl, tert-butyl), N-alkylazetidines (R = isopropyl, tertbutyl), and N-methylpyrrolidine. At high concentration, formation of a proton-bound homotrimer is observed in the case of N-methylaziridine. The homodimers stay intact inside the assembly over a large concentration range, thereby suggesting cooperative encapsulation. Both G3(MP2)B3 and G3B3 calculations of the proton-bound homodimers were used to investigate the enthalpy of the hydrogen bond in the proton-bound homodimers and suggest that the enthalpic gain upon formation of the proton-bound homodimers may drive guest encapsulation.

Pluth, Michael; Fiedler, Dorothea; Mugridge, Jeffrey; Bergman, Robert; Raymond, Kenneth

2008-10-01T23:59:59.000Z

330

Directed metalation of N,N-diethylbenzamides. Silylated benzamides for the synthesis of naturally occurring peri-methylanthraquinones and peri-methyl polycyclic aromatic hydrocarbons  

SciTech Connect (OSTI)

Efficient methodologies based on directed ortho metalation, fluoride-induced carbodesilylation, and metal-halogen exchange processes (Scheme I) are reported for the synthesis of peri-methyl-substituted anthraquinone natural products 5 and polycyclic aromatic hydrocarbons 6, 7. Benzamide 8 (Scheme II) is converted in a one-pot sequence into the disilylated derivative 10, which upon metalation, condensation with 3,5-dimethoxybenzaldehyde, CsF desilylation, and TsOH cyclization leads to the key phthalide 11. Compound 11 is transformed into deoxyerythrolaccin tris(methyl ether) 5c, which has been previously converted into the natural product 5a. For the synthesis of erythrolaccin tetrakis(methyl ether) 5d, the silyl and bromo benzamides 14 and 15 (Scheme III) are condensed with 3,5-dimethoxybenzaldehyde by CsF-induced carbodesilylation and metal-halogen exchange expedients, respectively, to give the phthalide 16, which is transformed into the target anthraquinone 55d by methods identical with those used in 5c. Along similar lines, the synthesis of 11-methyl-7,12-benz(a)anthraquinone (6a, Scheme IV), 8-methyl-7,12-benz(a)anthraquinone (6b), and 10-methyl-9,14-dibenz(a,c)anthraquinone (7) is described.

Mills, R.J.; Snieckus, V. (Univ. of Waterloo, Ontario (Canada))

1989-09-01T23:59:59.000Z

331

Effects of oxygenate concentration on species mole fractions in premixed n-heptane flames  

E-Print Network [OSTI]

-heptane/oxygenate mixtures were 2.7 and 3.4. Three different fuel oxygenates (i.e. MTBE, methanol, and ethanol) were tested tertiary-butyl ether (MTBE), ethyl tertiary-butyl ether (ETBE), and tertiary amyl methyl ether (TAME)) were considered as possible fuel oxygenates. MTBE and ethanol are the most common oxygenates currently used

Senkan, Selim M.

332

APPENDXD.CHP:Corel VENTURA  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

Report The Form EIA-819, "Monthly Oxygenate Report" provides production data for fuel ethanol and methyl tertiary butyl ether (MTBE). End-of-month stock data held at ethanol...

333

() Trichloromethane ()1,1,2,2-1,1,2,2-Tetrachloroethane  

E-Print Network [OSTI]

acetate () Ethylene glycol monobutyl ether () Ethylene glycol monomethy ether ()- O-dichlorobenzene ( ) Xylenes(o-,m-,p- isomers) () Cresol - 19 - #12;() Chlorobenzene () Amyl acetate () Isoamyl acetate () Isobutyl acetate () Isopropyl acetate () Ethyl acetate () Propyl acetate () Butyl acetate () Methyl acetate

Huang, Haimei

334

A Low-Carbon Fuel Standard for California Part 1: Technical Analysis  

E-Print Network [OSTI]

methyl-tertiary butyl ether (MTBE), from gasoline by 2004.MTBE was used to meet a requirement for gasoline to containbeginning in 2002, replacing MTBE with ethanol. According to

2007-01-01T23:59:59.000Z

335

Emissions of volatile organic compounds inferred from airborne flux measurements over a megacity  

E-Print Network [OSTI]

methyl-tertiary-butyl- ether (MTBE) and the biomass burningfrom all source categories. MTBE is a gasoline additive andwith the fuel tracer MTBE (e.g. 0.82 for MTBE/benzene).

Karl, T.; Apel, E.; Hodzic, A.; Riemer, D. D; Blake, D. R; Wiedinmyer, C.

2009-01-01T23:59:59.000Z

336

Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area  

E-Print Network [OSTI]

Methanol Ethanol Acetone MEK MTBE CO Methane UCI UCI TOGA/methyl tertiary butyl ether (MTBE), and toluene all ratioedthe observed decay. For MTBE, also a species that is not

2010-01-01T23:59:59.000Z

337

Soil type, crop and irrigation technique affect nitrogen leaching to groundwater  

E-Print Network [OSTI]

water contamination with MTBE (methyl tertiary-butyl ether,that areas vulnerable to MTBE are also vulner- able tothat affect the movement of MTBE. If only a small amount of

Letey, John; Vaughan, Peter

2013-01-01T23:59:59.000Z

338

Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2  

E-Print Network [OSTI]

methyl tertiary- butyl ether (MTBE) and its effect on plasmaand three VOCs (propyne, furan, MTBE) remained below their 3Ethanol Acetone MEK MAC MVK MTBE Furan CH 3 OH C 2 H 5 OH C

2010-01-01T23:59:59.000Z

339

A Low-Carbon Fuel Standard for California, Part 1: Technical Analysis  

E-Print Network [OSTI]

methyl-tertiary butyl ether (MTBE), from gasoline by 2004.MTBE was used to meet a requirement for gasoline to containbeginning in 2002, replacing MTBE with ethanol. According to

Farrell, Alexander E.; Sperling, Dan

2007-01-01T23:59:59.000Z

340

Factors influencing biological treatment of MTBE contaminated ground water  

E-Print Network [OSTI]

Methyl tertiary-butyl ether (MTBE) biodegradation in batchCometabolic degradation of MTBE by a cyclohexane-oxidizingof 49 Biological Treatment of MTBE Fortin, N. Y. , and M. A.

Stringfellow, William T.; Hines Jr., Robert D.; Cockrum, Dirk K.; Kilkenny, Scott T.

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Finding the missing stratospheric Bry: a global modeling study of CHBr3 and CH2Br2  

E-Print Network [OSTI]

Methanol Ethanol Acetone MEK MTBE CO Methane UCI UCI TOGA/methyl tertiary butyl ether (MTBE), and toluene all ratioedthe observed decay. For MTBE, also a species that is not

2010-01-01T23:59:59.000Z

342

Life-Cycle Water Impacts of U.S. Transportation Fuels  

E-Print Network [OSTI]

Drinking Water: Methyl Tertiary Butyl Ether (MTBE).http://www.epa.gov/mtbe/water.htm (11/30/10), Chiu, Y. W. ;LCFS LCI LP LPG MED MRO MSF MTBE MWD MWDOC NAICS NERC NETL

Scown, Corinne Donahue

2010-01-01T23:59:59.000Z

343

Emissions and engine performance from blends of soya and canola methyl esters with ARB {number_sign}2 diesel in a DCC 6V92TA MUI engine  

SciTech Connect (OSTI)

A Detroit Diesel 6V92TA MUI engine was operated on several blends of EPA No. 2 diesel, California ARB No. 2 diesel, soya methyl ester (SME) and canola methyl ester (CME). Various fuels and fuel blend characteristics were determined and engine emissions from these fuels and blends were compared. Increasing percentages of SME and CME blended with either ARB or EPA diesels led to increased emissions of NO{sub x}, CO{sub 2} and soluble particulate matter. Also noted were reductions in total hydrocarbons, CO and insoluble particulate matter. Chassis dynamometer tests conducted on a 20/80 SME/ARB blend showed similar emissions trends. The data suggest that certain methyl ester/No. 2 diesel blends in conjunction with delays in engine timing and technologies that reduce the soluble fraction of particulate emissions merit further exploration as emissions reducing fuel options for North American mass transits (except in California, which mandates ARB diesel).

Spataru, A.; Romig, C.

1995-12-31T23:59:59.000Z

344

Emissions and engine performance from blends of soya and canola methyl esters with ARB No. 2 diesel in a DDC 6V92TA MUI engine  

SciTech Connect (OSTI)

A Detroit Diesel 6V92TA MUI engine was operated on several blends of EPA No. 2 diesel, soya methyl ester (SME) and canola methyl ester (CME). Various fuels and fuel blend characteristics were determined and engine emissions from these fuels and blends were compared. Increasing percentages of SME and CME blended with either ARB or EPA diesels led to increased emissions of NO{sub x}, CO{sub 2} and soluble particulate matter. Also noted were reductions in total hydrocarbons, CO and insoluble particulate matter. Chassis dynamometer tests conducted on a 20/80 SME/ARB blend showed similar emission trends. The data suggest that certain methyl ester/No. 2 diesel blends in conjunction with technologies that reduce the soluble fraction of particulate emissions merit further exploration as emissions reducing fuel options for North American mass transit sectors (except California, which mandates ARB diesel).

Spataru, A.; Romig, C. [ADEPT Group, Inc., Los Angeles, CA (United States)

1995-11-01T23:59:59.000Z

345

Alkylating agent methyl methanesulfonate (MMS) induces a wave of global protein hyperacetylation: Implications in cancer cell death  

SciTech Connect (OSTI)

Protein acetylation modification has been implicated in many cellular processes but the direct evidence for the involvement of protein acetylation in signal transduction is very limited. In the present study, we found that an alkylating agent methyl methanesulfonate (MMS) induces a robust and reversible hyperacetylation of both cytoplasmic and nuclear proteins during the early phase of the cellular response to MMS. Notably, the acetylation level upon MMS treatment was strongly correlated with the susceptibility of cancer cells, and the enhancement of MMS-induced acetylation by histone deacetylase (HDAC) inhibitors was shown to increase the cellular susceptibility. These results suggest protein acetylation is important for the cell death signal transduction pathway and indicate that the use of HDAC inhibitors for the treatment of cancer is relevant.

Lee, Min-Young [Department of Biochemistry, College of Medicine, Dong-A University, 3-1, Dongdaeshin-Dong, Seo-Gu, Busan 602-714, South Korea (Korea, Republic of); Kim, Myoung-Ae [Department of Biochemistry, College of Medicine, Dong-A University, 3-1, Dongdaeshin-Dong, Seo-Gu, Busan 602-714, South Korea (Korea, Republic of); Kim, Hyun-Ju [Department of Biochemistry, College of Medicine, Dong-A University, 3-1, Dongdaeshin-Dong, Seo-Gu, Busan 602-714, South Korea (Korea, Republic of); Bae, Yoe-Sik [Department of Biochemistry, College of Medicine, Dong-A University, 3-1, Dongdaeshin-Dong, Seo-Gu, Busan 602-714, South Korea (Korea, Republic of); Park, Joo-In [Department of Biochemistry, College of Medicine, Dong-A University, 3-1, Dongdaeshin-Dong, Seo-Gu, Busan 602-714, South Korea (Korea, Republic of); Kwak, Jong-Young [Department of Biochemistry, College of Medicine, Dong-A University, 3-1, Dongdaeshin-Dong, Seo-Gu, Busan 602-714, South Korea (Korea, Republic of); Chung, Jay H. [Laboratory of Biochemical Genetics, NHLBI, NIH, 10 Center Drive, Bethesda, MD 20892 (United States); Yun, Jeanho [Department of Biochemistry, College of Medicine, Dong-A University, 3-1, Dongdaeshin-Dong, Seo-Gu, Busan 602-714, South Korea (Korea, Republic of)]. E-mail: yunj@dau.ac.kr

2007-08-24T23:59:59.000Z

346

(E)-2-[(2-Bromophenylimino)methyl]-5-methoxyphenol: X-ray and DFT-calculated structures  

SciTech Connect (OSTI)

The crystal structure of (E)-2-[(2-Bromophenylimino)methyl]-5-methoxyphenol is determined by using X-ray diffraction and then the molecular structure is investigated with density functional theory (DFT). X-Ray study shows that the title compound has a strong intramolecular O-H-N hydrogen bond and three dimensional crystal structure is primarily determined by C-H-{pi} and weak van der Waals interactions. The strong O-H-N bond is an evidence of the preference for the phenol-imine tautomeric form in the solid state. Optimized molecular geometry is calculated with DFT at the B3LYP/6-31G(d,p) level. The IR spectra of compound were recorded experimentally and calculated to compare with each other. The results from both experiment and theoretical calculations are compared in this study.

Kosar, B., E-mail: bkosar@omu.edu.tr; Albayrak, C. [Sinop University, Faculty of Education (Turkey); Odabasoglu, M. [Pamukkale University, Chemistry Program (Turkey); Bueyuekguengoer, O. [Ondokuz Mayis University, Faculty of Arts and Sciences (Turkey)

2010-12-15T23:59:59.000Z

347

Evidence for Thiol-Dependent Production of Oxygen Radicals by 4-Methyl-5-pyrazinyl-3H-1,2-dithiole-3-thione  

E-Print Network [OSTI]

to a peroxide species that undergoes a trace metal-catalyzed, Fenton-type reaction to generate oxygen radicalsEvidence for Thiol-Dependent Production of Oxygen Radicals by 4-Methyl-5-pyrazinyl-3H-1,2-dithiole the conversion of molecular oxygen to reactive oxygen radicals. Using a plasmid-based assay that monitors DNA

Gates, Kent. S.

348

Electronic Structures and Spin Topologies of -Picoliniumyl Radicals. A Study of the Homolysis of N-Methyl--picolinium and of Benzo-, Dibenzo-, and Naphthoannulated  

E-Print Network [OSTI]

topologies in metalloenzymes. Introduction The redox reactions of quaternized nitrogen heterocycles interesting. For example, the herbicide methyl viologen (paraquat) and the promising antitumor agent equivalent of superoxide O2 ·-.1­4 The repeated enzymatic reduction and back-oxidation by O2, i.e., the redox

Glaser, Rainer

349

Standard Thermodynamic Functions of Tripeptides N-Formyl-L-Methionyl-L-Leucyl-L-Phenylalaninol and N-Formyl-L-Methionyl-L-Leucyl-L-Phenylalanine Methyl Ester  

E-Print Network [OSTI]

The heat capacities of tripeptides N-formyl-l-methionyl-l-leucyl-l-phenylalaninol (N-f-MLF-OH) and N-formyl-l-methionyl-l-leucyl-l-phenylalanine methyl ester (N-f-MLF-OMe) were measured by precision adiabatic vacuum ...

Markin, Alexey V.

350

Electron-electron and electron-phonon interactions in irradiated N-methyl pyridinium derivatives with TCNQ studied by optical spectroscopy  

E-Print Network [OSTI]

1417 Electron-electron and electron-phonon interactions in irradiated N-methyl pyridinium derivatives with TCNQ studied by optical spectroscopy A. Graja and R. Swietlik Institute of Molecular Physics le 13 mars 1985, accepti le ler avril 1985) Résumé. 2014 L'irradiation électronique des

Boyer, Edmond

351

TpPtMe(H)2: Why Is There H/D Scrambling of the Methyl Group but Not Methane Loss?  

E-Print Network [OSTI]

TpPtMe(H)2: Why Is There H/D Scrambling of the Methyl Group but Not Methane Loss? Mark A. Iron, H ) hydrido-tris(pyrazolyl)borate) was investigated. This complex is remarkably resistant to methane loss; heating it in methanol at 55 °C does not lead to either methane or hydrogen loss. When CD3OD is used

Keinan, Ehud

352

Gestational exposure to diethylstilbestrol alters cardiac structure/function, protein expression and DNA methylation in adult male mice progeny  

SciTech Connect (OSTI)

Pregnant women, and thus their fetuses, are exposed to many endocrine disruptor compounds (EDCs). Fetal cardiomyocytes express sex hormone receptors making them potentially susceptible to re-programming by estrogenizing EDCs. Diethylstilbestrol (DES) is a proto-typical, non-steroidal estrogen. We hypothesized that changes in adult cardiac structure/function after gestational exposure to the test compound DES would be a proof in principle for the possibility of estrogenizing environmental EDCs to also alter the fetal heart. Vehicle (peanut oil) or DES (0.1, 1.0 and 10.0 ?g/kg/da.) was orally delivered to pregnant C57bl/6n dams on gestation days 11.5–14.5. At 3 months, male progeny were left sedentary or were swim trained for 4 weeks. Echocardiography of isoflurane anesthetized mice revealed similar cardiac structure/function in all sedentary mice, but evidence of systolic dysfunction and increased diastolic relaxation after swim training at higher DES doses. The calcium homeostasis proteins, SERCA2a, phospholamban, phospho-serine 16 phospholamban and calsequestrin 2, are important for cardiac contraction and relaxation. Immunoblot analyses of ventricle homogenates showed increased expression of SERCA2a and calsequestrin 2 in DES mice and greater molecular remodeling of these proteins and phospho-serine 16 phospholamban in swim trained DES mice. DES increased cardiac DNA methyltransferase 3a expression and DNA methylation in the CpG island within the calsequestrin 2 promoter in heart. Thus, gestational DES epigenetically altered ventricular DNA, altered cardiac function and expression, and reduced the ability of adult progeny to cardiac remodel when physically challenged. We conclude that gestational exposure to estrogenizing EDCs may impact cardiac structure/function in adult males. -- Highlights: ? Gestational DES changes cardiac SERCA2a and CASQ2 expression. ? Echocardiography identified systolic dysfunction and increased diastolic relaxation. ? DES increased DNMT3a expression and increased CpG DNA methylation. ? DES impacts fetal heart reducing cardiac reserve on challenge in adulthood. ? Fetal heart can be re-programmed by a non-steroidal estrogen.

Haddad, Rami, E-mail: rami.haddad@mail.mcgill.ca [Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada) [Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada); Division of Experimental Medicine, Department of Medicine, McGill University, 850 Sherbrooke Street, Montréal, Québec, Canada H3A 1A2 (Canada); Kasneci, Amanda, E-mail: amanda.kasneci@mail.mcgill.ca [Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada)] [Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada); Mepham, Kathryn, E-mail: katherine.mepham@mail.mcgill.ca [Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada) [Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada); Division of Experimental Medicine, Department of Medicine, McGill University, 850 Sherbrooke Street, Montréal, Québec, Canada H3A 1A2 (Canada); Sebag, Igal A., E-mail: igal.sebag@mcgill.ca [Division of Cardiology, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada); and others

2013-01-01T23:59:59.000Z

353

Vapor-liquid equilibria of binary and ternary mixtures of cyclohexane, 3-methyl-2-butanone, and octane at 101.3 kPa  

SciTech Connect (OSTI)

Vapor-liquid equilibria were measured at 101.3 kPa for the three binary and one ternary mixtures of cyclohexane, 3-methyl-2-butanone, and octane. The isobaric T-x-y data were reported, including an azeotropic point for the binary mixture cyclohexane + 3-methyl-2-butanone. The virial equation of state truncated after the second coefficient was used to calculate the vapor-phase fugacity coefficients. The Tsonopoulos correlation equation was applied to determine the second virial coefficients. Various activity coefficient models of the Wilson, the NRTL, and the UNIQUAC equations were used to correlate the binary experimental vapor-liquid equilibrium results. Optimally-fitted binary parameters of the activity coefficient models were obtained and those parameters of the NRTL model were employed to predict the ternary vapor-liquid equilibria. Satisfactory results were presented for the correlation and prediction of the vapor-liquid equilibrium data on binary and ternary mixtures.

Chen, C.C.; Tang, M.; Chen, Y.P. [National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Chemical Engineering] [National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Chemical Engineering

1996-05-01T23:59:59.000Z

354

Solution medium control of the photoredox yield in the Ru(bpy)/sub 3//sup 2 +//methyl viologen/EDTA system  

SciTech Connect (OSTI)

The observed quantum yield of formation of the methyl viologen radical cation, phi(MV/sup +/-), upon 450-nm irradiation of the Ru(bpy)/sub 3//sup 2 +//methyl viologen dication/EDTA system at pH 11.0 is dependent on the concentrations of all three components. Under the conditions of the experiments, phi(MV/sup +/-)approx. =2eta/sub cr/ where eta/sub cr/ is the efficiency of release of redox products from the solvent cage. The maximum value of eta/sub cr/ is approx. =0.17 at high concentrations of all components where the photosensitizer, electron relay, and sacrificial electron donor exist as ion-paired aggregates within a single solvent-caged unit. 3 figures.

Mandal, K.; Hoffman, M.Z.

1984-01-19T23:59:59.000Z

355

Studies on the binding of 5-N-methylated quindoline derivative to human telomeric G-quadruplex  

SciTech Connect (OSTI)

Research highlights: {yields} Hydrophobic interaction provided an important driving force for the interaction between ligand and G-quadruplex. {yields} Constrained water molecules were released from surface of G-tetrad upon the formation of the complex. {yields} The end-stacking mode for quindoline derivative was validated through UV-vis, ITC, steady-state, and time-resolved fluorescence experiment. {yields} The binding of compound 1 to quadruplex was found to be a temperature-dependent and enthalpy-entropy compensation process. -- Abstract: Quindoline derivatives as telomeric quadruplex ligands have shown good biological activity for telomerase inhibition. In the present study, we used spectroscopic and calorimetric methods to investigate the interactions between a quindoline derivative (5-methyl-11-(2-morpholinoethylamino)-10-H-indolo-[3,2-b]quinolin-5-ium iodide, compound 1) and human telomeric G-quadruplex. The thermodynamic studies using isothermal titration calorimetry (ITC) indicated that their binding process was temperature-dependent and enthalpy-entropy co-driven. The significant negative heat capacity was obtained experimentally from the temperature dependence of enthalpy changes, which was consistent with that from theoretical calculation, and all suggesting significant hydrophobic contribution to the molecular recognition process. Based on the results from UV-vis, ITC, steady-state and time-resolved fluorescence, their binding mode was determined as two ligand molecules stacking on the quartets on both ends of the quadruplex. These results shed light on rational design and development of quindoline derivatives as G-quadruplex binding ligands.

Xu, Wei; Tan, Jia-Heng; Chen, Shuo-Bin; Hou, Jin-Qiang; Li, Ding [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China)] [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Huang, Zhi-Shu, E-mail: ceshzs@mail.sysu.edu.cn [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China)] [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Gu, Lian-Quan, E-mail: cesglq@mail.sysu.edu.cn [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China)] [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China)

2011-03-18T23:59:59.000Z

356

Complete kinetic isotope effect description of transition states for acid-catalyzed hydrolyses of methyl. cap alpha. - and. beta. -glucopyranosides  

SciTech Connect (OSTI)

The following kinetic isotope effects (k/sub light//k/sub heavy/) have been measured by the isotopic quasi-racemate method for the hydrolyses of methyl ..cap alpha..- and ..beta..-glucopyranosides, respectively in 2.0 M HClO/sub 4/ at 80/sup 0/C (..cap alpha..-D 1.137 +/- 0.007, 1.089 +/- 0.006; ..beta..-D 1.073 +/- 0.003, 1.045 +/- 0.004; ..gamma..-D (C5) 0.987 +/- 0.002, 0.971 +/- 0.003; leaving group d/sub 3/ 1.006 +/- 0.001, 1.015 +/- 0.002; leaving group /sup 18/O 1.026 +/- 0.001, 1.024 +/ +/- 0.002; anomeric /sup 13/C 1.007 +/- 0.001, 1.011 +/- 0.002). In conjunction with studies of the effect of added solutes on the rates of hydrolysis of various aldopyranosyl derivatives, which indicate such reactions are truly unimolecular, and model ring /sup 18/O and ..beta..-deuterium effects, it is possible to locate the dihedral angles about the O5-C1 and C1-C2 bonds at the transition state using these data. If the dihedral angles so derived are used as constraints in calculations using N.L. Allinger's MM2 molecular mechanics program, transition-state structures are obtained. The geometry of these transition states stands in contradiction to the theory of stereoelectronic control.

Bennet, A.J.; Sinnott, M.L.

1986-11-12T23:59:59.000Z

357

Electrogenic and electroneutral pathways for methyl viologen-mediated transmembrane oxidation-reduction across dihexadecylphosphate vesicular membranes  

SciTech Connect (OSTI)

Two pathways for transmembrane reduction of dihexadecylphosphate (DHP) vesicle-entrapped Co(bpy)[sub 3][sup 3+] ion by photogenerated methyl viologen radical cation have been identified by quantitative evaluation of the reaction kinetics. One pathway involves electrogenic diffusion of MV[sup +] and the other electroneutral diffusion of MV[sup 0] across the bilayer. The pathways were clearly distinguished by the self-impeding character of the electrogenic reaction, which was progressively retarded as the membrane polarization increased, and by the net stoichiometry of viologen uptake accompanying transmembrane oxidation-reduction. The first-order rate constants for transmembrane diffusion of MV[sup +] and MV[sup 0] were estimated to be 2.7 x 10[sup [minus]2] s[sup [minus]1] and 1.1 x 10[sup 3] s[sup [minus]1], respectively, at 23[degree]C. The rate constant for MV[sup +] diffusion is identical to the value previously measured by [sup 14]C-isotopic labeling methods, and other kinetic parameters were consistent with thermodynamic data obtained from measurements of Donnan equilibria. 31 refs., 7 figs., 2 tabs.

Lymar, S.V. (Oregon Graduate Inst. of Science and Technology, Portland, OR (United States) Inst. of Catalysis, Novosibirsk (Russian Federation)); Hurst, J.K. (Oregon Graduate Inst. of Science and Technology, Portland, OR (United States))

1994-01-20T23:59:59.000Z

358

Photocatalytic degradation of methyl orange dye in water solutions in the presence of MWCNT/TiO{sub 2} composites  

SciTech Connect (OSTI)

Highlights: ? MWCNTs/TiO{sub 2} composites were obtained to degrade organic dyes in water. ? MWCNT/TiO{sub 2} composites were analyzed by photocatalysis and structural characterization. ? The photocatalytic shows efficient method for the degradation of dyes from aqueous effluents. - Abstract: The textile and dyestuff industries are the primary sources of the release of synthetic dyes into the environment and usually there are major pollutants in dye wastewaters. Because of their toxicity and slow degradation, these dyes are categorized as environmentally hazardous materials. In this context, carbon nanotubes/TiO{sub 2} (CNTs/TiO{sub 2}) composites were prepared using multi-walled CNTs (MWCNTs), titanium (IV) propoxide and commercial TiO{sub 2} (P25{sup ®}) as titanium oxide sources, to degrade the methyl orange dye in solution through photocatalyst activity using UV irradiation. The composites were prepared by solution processing followed by thermal treatment at 400, 500 and 600 °C. The heterojunction between nanotubes and TiO{sub 2} was confirmed by XRD, specific surface area. The coating morphology was observed with SEM and TEM.

Da Dalt, S., E-mail: silvana.da.dalt@ufrgs.br [Department of Material, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99, Laboratory 705C, ZIP 90035-190, Porto Alegre, RS (Brazil); Alves, A.K.; Bergmann, C.P. [Department of Material, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99, Laboratory 705C, ZIP 90035-190, Porto Alegre, RS (Brazil)

2013-05-15T23:59:59.000Z

359

Poly(methyl methacrylate) as a self-assembled gate dielectric for graphene field-effect transistors  

SciTech Connect (OSTI)

We investigate poly(methyl methacrylate) (PMMA) as a low thermal budget organic gate dielectric for graphene field effect-transistors (GFETs) based on a simple process flow. We show that high temperature baking steps above the glass transition temperature (?130?°C) can leave a self-assembled, thin PMMA film on graphene, where we get a gate dielectric almost for “free” without additional atomic layer deposition type steps. Electrical characterization of GFETs with PMMA as a gate dielectric yields a dielectric constant of k?=?3.0. GFETs with thinner PMMA dielectrics have a lower dielectric constant due to decreased polarization arising from neutralization of dipoles and charged carriers as baking temperatures increase. The leakage through PMMA gate dielectric increases with decreasing dielectric thickness and increasing electric field. Unlike conventional high-k gate dielectrics, such low-k organic gate dielectrics are potentially attractive for devices such as the proposed Bilayer pseudoSpin Field-Effect Transistor or flexible high speed graphene electronics.

Sanne, A.; Movva, H. C. P.; Kang, S.; McClellan, C.; Corbet, C. M.; Banerjee, S. K. [Microelectronics Research Center, University of Texas, Austin, Texas 78758 (United States)

2014-02-24T23:59:59.000Z

360

Hydrothermal synthesis of Mn vanadate nanosheets and visible-light photocatalytic performance for the degradation of methyl blue  

SciTech Connect (OSTI)

Graphical abstract: - Highlights: • Mn vanadate nanosheets have been synthesized by simple hydrothermal process. • The formation of Mn vanadate nanosheets can be controlled by growth conditions. • Mn vanadate nanosheets exhibit good photocatalytic activities for methyl blue. - Abstract: Mn vanadate nanosheets have been synthesized via a facile hydrothermal route using ammonium metavanadate and Mn acetate as the raw materials, polyvinyl pyrrolidone (PVP) as the surfactant. X-ray diffraction (XRD) shows that the Mn vanadate nanosheets are composed of monoclinic MnV{sub 2}O{sub 6} phase. Scanning electron microscopy (SEM) observation indicates that the nanosheets have the average thickness of about 50 nm, length of 2–10 ?m and width of 800 nm to 2 ?m. The growth process of the Mn vanadate nanosheets has also been discussed based on the analysis of the roles of the growth conditions on the formation of the Mn vanadate nanosheets. The nanosheets show good photocatalytic activities for the degradation of methylene blue (MB) under visible light irradiation. About 72.96% MB can be degraded after visible light irradiation for 1 h over 10 mg Mn vanadate nanosheets in 10 mL MB solution with the concentration of 10 mg L{sup ?1}.

Pei, L.Z., E-mail: lzpei@ahut.edu.cn; Xie, Y.K.; Pei, Y.Q.; Jiang, Y.X.; Yu, H.Y.; Cai, Z.Y.

2013-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Published Ahead of Print 1 July 2011. 2011, 193(17):4549. DOI: 10.1128/JB.00415-11.J. Bacteriol.  

E-Print Network [OSTI]

Laboratory, Joint Genome Institute, Biosciences Division Genome Science B6, Los Alamos, New Mexico 875454 ; U and energy source (9, 10, 11, 14). This strain can also grow on other ethers (e.g., 2-methyl-1,3- dioxolane and butyl methyl ether), alcohols, and benzene as the sole carbon and energy source, and it can grow

Alvarez-Cohen, Lisa

362

(distillation) (Le Chatelier  

E-Print Network [OSTI]

acetate(methyl-, ethyl-, butyl-) , methanol isobutene MTBE , ethanol isobutene ETBE , methanol 2-methyl-1% MTBE 3 DMC . 2% 1990 MTBE 1999 3 2002 MTBE . [ 1-1 ] Phosgene process polycarbonate(PC) 50/ . DMC DMC MTBE / . ( : Amoco, "Review of DMC Manufacture and its

Hong, Deog Ki

363

Modulation of DL-. alpha. -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/quisqualate receptors by phospholipase A sub 2 : A necessary step in long-term potentiation  

SciTech Connect (OSTI)

The effects of kainate (KA)-induced epileptic seizures on the binding properites of hippocampal glutamate receptors, on the modulation of DL-{alpha}-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/quisqualate receptor by phospholipase A{sub 2} (PLA{sub 2}), and on the formation of long-term potentiation (LTP) were studied in hippocampal membranes and hippocampal slices. Systemic administration of KA produced specific changes in the binding properties of the AMPA/quisqualate receptors and its regulation. Whereas the binding of various ligands to the N-methyl-D-aspartate receptors was not modified by KA treatment, there was a singificant decrease in the maximal number of binding sites for ({sup 3}H)AMPA. The loss of LTP was not due to changes in postsynaptic responses elicited by the bursts that trigger the potentiation effect, thus suggesting that KA treatment disrupts processes that follow N-methyl-D-aspartate receptor activation. Systemic administration of KA was associated with calpain activation as the amount of spectrin breakdown products was increased severalfold in hippocampus but not in cerebellum. Pretreatment of telencephalic membranes with calpain greatly reduced the PLA{sub 2}-induced increase in ({sup 3}H)AMPA binding. The results provide evidence in favor of an essential role of PLA{sub 2} in the development of LTP and suggest that the order of activation of different calcium-dependent processes is critical for producing the final changes underlying LTP.

Massicotte, G.; Baudry, M. (Univ. of Southern California, Los Angeles (United States)); Vanderklish, P.; Lynch, G. (Univ. of California, Irvine (United States))

1991-03-01T23:59:59.000Z

364

DNA methylation-dependent regulation of TrkA, TrkB, and TrkC genes in human hepatocellular carcinoma  

SciTech Connect (OSTI)

Research highlights: {yields} Expression of TrkA, TrkB, and TrkC is significantly elevated in human hepatocellular carcinoma. {yields} Downregulation of Trks is correlated with their promoter hypermethylation. {yields} Inhibiting DNA methylation restored expression of Trks in normal liver cell lines. {yields} Trks promote the proliferation of hepatocellular carcinoma. {yields} Trks induce expression of the metastatic regulator, Twist. -- Abstract: The tropomyosin-related kinase (Trk) family of neurotrophin receptors, TrkA, TrkB and TrkC, has been implicated in the growth and survival of human cancers. Here we report that Trks are frequently overexpressed in hepatocellular carcinoma (HCC) from patients and human liver cancer cell lines. To unravel the underlying molecular mechanism(s) for this phenomenon, DNA methylation patterns of CpG islands in TrkA, TrkB, and TrkC genes were examined in normal and cancer cell lines derived from liver. A good correlation was observed between promoter hypermethylation and lower expression of TrkA, TrkB, and TrkC genes, which was supported by the data that inhibiting DNA methylation with 5-azacytidine restored expression of those genes in normal liver cell lines. Furthermore, Trks promoted the proliferation of HepG2 and induced expression of the metastatic regulator, Twist. These results suggest that Trks may contribute to growth and metastasis of liver cancer.

Jin, Wook [Laboratory of Molecular Disease and Cell Regulation, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon (Korea, Republic of)] [Laboratory of Molecular Disease and Cell Regulation, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon (Korea, Republic of); Lee, Jong-Joo [Department of Environmental Medical Biology, Institute of Tropical Medicine, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)] [Department of Environmental Medical Biology, Institute of Tropical Medicine, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kim, Min Soo [Laboratory of Molecular Disease and Cell Regulation, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon (Korea, Republic of)] [Laboratory of Molecular Disease and Cell Regulation, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon (Korea, Republic of); Son, Byung Ho [Department of Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, 108 Pyung-dong, Jongro-gu, Seoul 110-746 (Korea, Republic of)] [Department of Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, 108 Pyung-dong, Jongro-gu, Seoul 110-746 (Korea, Republic of); Cho, Yong Kyun, E-mail: choyk2004@hanmail.net [Division of Gastroenterology, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, 108 Pyung-dong, Jongro-gu, Seoul 110-746 (Korea, Republic of); Kim, Hyoung-Pyo, E-mail: kimhp@yuhs.ac [Department of Environmental Medical Biology, Institute of Tropical Medicine, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)] [Department of Environmental Medical Biology, Institute of Tropical Medicine, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)

2011-03-04T23:59:59.000Z

365

Electrodeposition of nickel-aluminum alloys from the aluminum chloride-1-methyl-3-ethylimidazolium chloride room temperature molten salt  

SciTech Connect (OSTI)

The electrodeposition of Ni and Ni-Al alloys on glassy carbon was investigated in the 66.7--33.3 mole percent (m/o) Al chloride-1-methyl-3-ethylimidazolium chloride molten salt containing electrogenerated Ni(II) at 40 C. The electrodeposition of Ni on glassy carbon involves 3-D progressive nucleation on a finite number of active sites with hemispherical diffusion-controlled growth of the nuclei. At potentials slightly more negative than those needed to induce the reduction of Ni(II) to the metal, Al is codeposited with Ni to produce Ni-Al alloys. Controlled-potential and controlled-current experiments revealed that it is possible to produce alloy deposits containing up to approximately 40 atomic percent (a/o) Al under conditions that circumvent the bulk deposition of Al. The Al content of the Ni-Al deposit was found to vary linearly with the deposition potential but nonlinearly with the current density. The electrodeposited Ni-Al alloys are thermodynamically unstable with respect to Ni(II), i.e., immersion of the alloy deposit in melt containing Ni(II) under open-circuit conditions leads to a reduction in the Al content of the alloy. The mechanism of alloy formation appears to involve underpotential deposition of Al on the developing Ni deposit; however, alloy formation must be kinetically hindered because the Al content is always less than predicted from theoretical considerations. Ni-Al alloys produced at 0.30 V in melt containing Ni(II) and 20% (w/w) benzene as a cosolvent contained about 15 a/o Ni and were of high quality with a disordered fcc structure, but alloys produced at more negative potentials had the visual appearance of a loosely adherent, finely divided, black powder and were heavily contaminated with chloride, probably as a result of the occlusion of the molten salt solvent by the dendritic alloy deposit during deposit growth.

Pitner, W.R.; Hussey, C.L. [Univ. of Mississippi, University, MS (United States). Dept. of Chemistry; Stafford, G.R. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Materials Science and Engineering Lab.

1996-01-01T23:59:59.000Z

366

Synthesis and characterization of hybrid materials based on 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid and Dawson-type tungstophosphate K{sub 7}[H{sub 4}PW{sub 18}O{sub 62}].18H{sub 2}O and K{sub 6}[P{sub 2}W{sub 18}O{sub 62}].13H{sub 2}O  

SciTech Connect (OSTI)

In this study, we synthesized hybrid materials using well-Dawson polyoxometalates (POMs), K{sub 7}[H{sub 4}PW{sub 18}O{sub 62}].18H{sub 2}O or K{sub 6}[P{sub 2}W{sub 18}O{sub 62}].13H{sub 2}O and a room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF{sub 4}]). K, W, P and CHN elemental analysis showed that one mole of [H{sub 4}PW{sub 18}O{sub 62}]{sup 7-} reacts with 6 moles of BMIM{sup +} and one mole of [P{sub 2}W{sub 18}O{sub 62}]{sup 6-} reacts with 4 moles of BMIM{sup +} to form, respectively, K[BMIM]{sub 6}H{sub 4}PW{sub 18}O{sub 62} and K{sub 2}[BMIM]{sub 4}P{sub 2}W{sub 18}O{sub 62}. X-ray diffraction illustrated amorphous structure of the hybrid materials. FT-IR spectra showed the presence of both 1-butyl-3-methylimidazolium cation and the Dawson anion. TG analysis displayed a relative thermal stability of the hybrid materials compared to the parents Dawson POMs. Cyclic voltammetry showed that the reduction peak potentials of the Dawson anion in the hybrid materials shift towards negative values and the shift is more pronounced for K[BMIM]{sub 6}H{sub 4}PW{sub 18}O{sub 62} compared to K{sub 2}[BMIM]{sub 4}P{sub 2}W{sub 18}O{sub 62}. This was attributed to a decrease in the acidity of the Dawson POM anion in the hybrid material. -- Graphical abstract: Powder XRD patterns of (a) PW{sub 18}, (b) K[BMIM]{sub 6}H{sub 4}PW{sub 18}O{sub 62}, (c) P{sub 2}W{sub 18}, and (d) K{sub 2}[BMIM]{sub 4}P{sub 2}W{sub 18}O{sub 62}. Display Omitted Research highlights: {yields} 1-butyl-3-methylimidazolium tetrafluoroborate([BMIM][BF{sub 4}]) reacts with K{sub 7}[H{sub 4}PW{sub 18}O{sub 62}].18H{sub 2}O to form K[BMIM]{sub 6}H{sub 4}PW{sub 18}O{sub 62}. {yields} [BMIM][BF{sub 4}] reacts with K{sub 6}[P{sub 2}W{sub 18}O{sub 62}].13H{sub 2}O to form K{sub 2}[BMIM]{sub 4}P{sub 2}W{sub 18}O{sub 62}. {yields} K[BMIM]{sub 6}H{sub 4}PW{sub 18}O{sub 62} and K{sub 2}[BMIM]{sub 4}P{sub 2}W{sub 18}O{sub 62} displayed amorphous structures. {yields} K[BMIM]{sub 6}H{sub 4}PW{sub 18}O{sub 62} and K{sub 2}[BMIM]{sub 4}P{sub 2}W{sub 18}O{sub 62} illustrated low water content. {yields} K[BMIM]{sub 6}H{sub 4}PW{sub 18}O{sub 62} and K{sub 2}[BMIM]{sub 4}P{sub 2}W{sub 18}O{sub 62} showed improved thermal stability.

Ammam, Malika, E-mail: m78ammam@yahoo.f [Department of Metallurgy and Materials Engineering (MTM), K.U Leuven, Kasteelpark Arenberg 44, B-3001 Heverlee (Belgium); Fransaer, Jan [Department of Metallurgy and Materials Engineering (MTM), K.U Leuven, Kasteelpark Arenberg 44, B-3001 Heverlee (Belgium)

2011-04-15T23:59:59.000Z

367

Reactivity of the Quinone Methide of Butylated hydroxytoluene in Solution  

E-Print Network [OSTI]

BHT is a common antioxidant in pharmaceutical formulations and when oxidized it forms a quinone methide (QM). QM is a highly reactive electrophilic species which can undergo nucleophilic addition. This research investigated ...

Willcockson, Maren Gulsrud

2011-08-31T23:59:59.000Z

368

Conversion of Lignocellulosic Biomass to Ethanol Butyl Acrylate  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTieCelebrate EarthEnergy Contractor&3-1Program Managers

369

Experimental study and chemical analysis of n-heptane homogeneous charge compression ignition combustion with port injection of reaction inhibitors  

SciTech Connect (OSTI)

The control of ignition timing in the homogeneous charge compression ignition (HCCI) of n-heptane by port injection of reaction inhibitors was studied in a single-cylinder engine. Four suppression additives, methanol, ethanol, isopropanol, and methyl tert-butyl ether (MTBE), were used in the experiments. The effectiveness of inhibition of HCCI combustion with various additives was compared under the same equivalence ratio of total fuel and partial equivalence ratio of n-heptane. The experimental results show that the suppression effectiveness increases in the order MTBE < isopropanol << ethanol < methanol. But ethanol is the best additive when the operating ranges, indicated thermal efficiency, and emissions are considered. For ethanol/n-heptane HCCI combustion, partial combustion may be observed when the mole ratio of ethanol to that of total fuel is larger than 0.20; misfires occur when the mole ratio of ethanol to that of total fuel larger than 0.25. Moreover, CO emissions strongly depend on the maximum combustion temperature, while HC emissions are mainly dominated by the mole ratio of ethanol to that of total fuel. To obtain chemical mechanistic informations relevant to the ignition behavior, detailed chemical kinetic analysis was conducted. The simulated results also confirmed the retarding of the ignition timing by ethanol addition. In addition, it can be found from the simulation that HCHO, CO, and C{sub 2}H{sub 5}OH could not be oxidized completely and are maintained at high levels if the partial combustion or misfire occurs (for example, for leaner fuel/air mixture). (author)

Lue, Xingcai; Ji, Libin; Zu, Linlin; Hou, Yuchun; Huang, Cheng; Huang, Zhen [School of Mechanical and Power Engineering, Shanghai Jiaotong University, Shanghai (China)

2007-05-15T23:59:59.000Z

370

Numerical study of the effect of oxygenated blending compounds on soot formation in shock tubes  

SciTech Connect (OSTI)

This numerical study deals with the influence of blends on the amount of soot formed in shock tubes, which were simulated by assuming a homogeneous plug flow reactor model. For this purpose, first, the reaction model used here was validated against experimental results previously obtained in the literature. Then, the soot volume fractions of various mixtures of methyl tert-butyl ether (MTBE)-benzene, isobutene-benzene, methanol-benzene, and ethanol-benzene diluted in argon were simulated and compared to the results of benzene-argon pyrolysis at 1721 K and 5.4 MPa. For MTBE, isobutene, methanol, and ethanol, small amounts of additives to benzene-argon mixtures promoted soot formation, for the shock tube model assumed, while higher concentrations of these additives led to smaller soot volume fractions in comparison to pure benzene-argon pyrolysis. The most significant soot promotion effect was found for the additives MTBE and isobutene. The channel for MTBE decomposition producing isobutene and methanol is very effective at temperatures beyond 1200 K. Thus, both MTBE-benzene and isobutene-benzene mixtures diluted in argon showed rather similar behavior in regard to soot formation. Special emphasis was directed toward the causes for the concentration-dependent influence of the blends on the amount of soot formed. Aromatic hydrocarbons and acetylene were identified as key gas-phase species that determine the trends in the formation of soot of various mixtures. From reaction flux analysis for phenanthrene, it was deduced that the combinative routes including phenyl species play a major role in forming PAHs, especially at early reaction times. It is found that the additives play an important role in providing material to grow side chains, such as by reaction channels including phenylacetylene or benzyl, which are confirmed to form aromatic hydrocarbons and thus to influence the amount of soot formed, particularly when the concentrations of the blends are increased. (author)

Boehm, H. [Physikalische Chemie I, Universitaet Bielefeld (Germany); Braun-Unkhoff, M. [Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Stuttgart (Germany)

2008-04-15T23:59:59.000Z

371

Iron optimization for Fenton-driven oxidation of MTBE-spent granular activated carbon  

SciTech Connect (OSTI)

Fenton-driven chemical oxidation of methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) was accomplished through the addition of iron (Fe) and hydrogen peroxide (H{sub 2}O{sub 2}) (15.9 g/L; pH 3). The GAC used was URV, a bituminous-coal based carbon. The Fe concentration in GAC was incrementally varied (1020-25 660 mg/kg) by the addition of increasing concentrations of Fe solution (FeSO4{center_dot}7H{sub 2}O). MTBE degradation in Fe-amended GAC increased by an order of magnitude over Fe-unamended GAC and H{sub 2}O{sub 2} reaction was predominantly (99%) attributed to GAC-bound Fe within the porous structure of the GAC. Imaging and microanalysis of GAC particles indicated limited penetration of Fe into GAC. The optimal Fe concentration was 6710 mg/kg (1020 mg/kg background; 5690 mg/kg amended Fe) and resulted in the greatest MTBE removal and maximum Fe loading oxidation efficiency (MTBE oxidized (g)/Fe loaded to GAC(mg/Kg)). At lower Fe concentrations, the H{sub 2}O{sub 2} reaction was Fe limited. At higher Fe concentrations, the H{sub 2}O{sub 2} reaction was not entirely Fe limited, and reductions in GAC surface area, GAC pore volume, MTBE adsorption, and Fe loading oxidation efficiency were measured. Results are consistent with nonuniform distribution of Fe, pore blockage in H{sub 2}O{sub 2} transport, unavailable Fe, and limitations in H{sub 2}O{sub 2} diffusive transport, and emphasize the importance of optimal Fe loading. 22 refs., 6 figs., 2 tabs.

Scott G. Huling; Patrick K. Jones; Tony R. Lee [U.S. Environmental Protection Agency, Ada, OK (United States). Office of Research and Development, National Risk Management Research Laboratory

2007-06-01T23:59:59.000Z

372

A review of the environmental behavior and fate of fuel oxygenates  

SciTech Connect (OSTI)

The ways in which fuel oxygenate compounds behave in water, soil, and air are determined by how they partition among the different media. The behavior of a gasoline oxygenate in water is affected by the oxygenate`s (1) solubility in water from gasoline: (2) partitioning between water and soil materials; and (3) partitioning between air and water. Water in equilibrium with oxygenated gasoline can contain high concentrations of the oxygenate. For example, at room temperature water solubility of methyl tert-butyl ether (MTBE) will be about 5,000 mg/L for a gasoline that is 10% MTBE by weight. In contrast, the total hydrocarbon solubility in water is typically about 120 mg/L for nonoxygenated gasoline. Fuel oxygenates sorb only weakly to soil and aquifer materials. Therefore, sorption to these materials will not significantly retard their transport by ground water. Fuel oxygenates tend to partition into atmospheric water, including precipitation. For example, washout of gas-phase MTBE by precipitation would not, by itself, greatly alter the gas-phase concentration of the compound in the atmosphere. Nevertheless, the partitioning of MTBE to precipitation is strong enough to allow for submicrogram per liter to 3 pg/L or more inputs of MTBE to ground water and surface water. Occurrence data for MTBE in water and air supports partition theoretical calculations. MTBE and other alkyl ether oxygenates have half lives in the atmosphere that range from about 1 to 14 days. These compounds are generally considered recalcitrant in ground water; whereas ethanol and methanol will readily undergo microbial degradation except where present in concentrations toxic to microorganisms.

Squillace, P.J.

1995-12-31T23:59:59.000Z

373

Remediation of overlapping benzene/MTBE and MTBE-only plumes: A case study  

SciTech Connect (OSTI)

Two overlapping dissolved hydrocarbon plumes were identified in the shallow water-bearing zone at a commercial vehicle service and fueling facility. Plume 1 originated from a pre-1993 gasoline product line/dispenser leak. This plume contained a relatively common mix of benzene, toluene, ethylbenzene, xylenes (BTEX), and methyl tert-butyl ether (MTBE); benzene and MTBE were identified as the Plume 1 contaminants of concern based on their detection at approximately 200 {mu}g/l each, which exceeded regulatory guidance. Plume 2, which was detected in the tank cavity during UST removal, resulted from gasoline line leaks/underground storage tank overfills. Although the majority of impacted soils in both the dispenser and tank cavity areas were removed during UST excavation, rainfall during impacted soil removal mobilized the MTBE contained in the soils to groundwater. As a result, Plume 2 contained approximately 900 {mu}g/l MTBE while BTEX compounds were non-detect. Although the impacted zone sustained an approximate yield of only 0.3 gallon per minute, Pennsylvania regulations dictate that this zone must be treated as an aquifer. The failure of remediating gasoline plumes using pump-and-treat has been predominantly due to BTEX`s tendency to adsorb onto soil, creating a residual-phase product layer which acts as a continuing source of dissolved-phase BTEX. Based on this experience, most groundwater and remediation professionals reject pump-and-treat as a viable remedial option, except in situations where controlling groundwater movement is the predominant goal.

Carpenter, P.L. [TolTest, Inc., Pittsburgh, PA (United States); Vinch, C.A. [Ryder Transportation Services, Lawrenceville, NJ (United States)

1997-12-31T23:59:59.000Z

374

Detections of MTBE in surficial and bedrock aquifers in New England  

SciTech Connect (OSTI)

The gasoline additive methyl tert-butyl ether (MTBE) was detected in 24% of water samples collected from surficial and bedrock aquifers in areas of New England. MTBE was the most frequently detected volatile organic compound among the 60 volatile chemicals analyzed and was present in 33 of 133 wells sampled from July 1993 through September 1995. The median MTBE concentration measured in ground-water samples was 0.45 microgram per liter and concentrations ranged from 0.2 to 5.8 microgram per liter. The network of wells sampled for MTBE consisted of 103 monitoring wells screened in surficial sand-and-gravel aquifers and 30 domestic-supply wells in fractured crystalline bedrock aquifers. Seventy-seven percent of all MTBE detections were from 26 shallow monitoring wells screened in surficial aquifers. MTBE was detected in42% of monitoring wells in urban areas. In agricultural areas, MTBE was detected i 8% (2 of 24) of wells and was not detected in undeveloped areas. Sixty-two percent of the MTBE detections in surficial aquifers were from wells within 0.25 mile of gasoline stations or underground gasoline storage tanks; all but one of these wells were in Connecticut and Massachusetts, where reformulated gasoline is used. MTBE was detected in 23% of deep domestic-supply wells that tapped fractured bedrock aquifers. MTBE was detected in bedrock wells only in Connecticut and Massachusetts; land use near the wells was suburban to rural, and none of the sampled bedrock wells were within 0.25 mile of a gasoline station.

Grady, S.J. [Geological Survey, Hartford, CT (United States)

1995-12-31T23:59:59.000Z

375

Remediation of a fractured clay soil contaminated with gasoline containing MTBE  

SciTech Connect (OSTI)

Gasoline and other light non-aqueous phase liquids (LNAPLs) released into fractured clay soils initially move by advection of the LNAPL through the fractures. Once advective movement of the LNAPL ceases, dissolution of the gasoline components into the pore water and diffusion into the intact blocks of clay becomes an important transport process. The aqueous-phase flux of each compound in the mixture depends in large part upon its aqueous solubility. For example, a low-solubility compound like isooctane remains primarily in the fracture in the LNAPL. A high-solubility compound, like methyl-tert-butyl ether (MTBE), dissolves readily and may move almost entirely into the clay matrix. The distribution of compounds between the matrix and the fractures will have an important impact on the rate at which the gasoline contaminated soil can be remediated. In this context, the presence of soluble additives like MTBE can significantly impact the risk and remediation time for the, soil. Beginning in 1993 a field study to examine the applicability of air flushing for remediation of low-permeability soils was sponsored by API. The study focused on a variety of soil vapor extraction (SVE) and in situ air sparging (IAS) approaches for mass removal and risk reduction. The source of gasoline contamination in this study was a release of 50 liters of a mixture containing 14 gasoline hydrocarbons ranging from pentane to naphthalene, and including MTBE. The mixture was released into the shallow subsurface and allowed to redistribute for 10 months prior to air flushing startup. Numerical modeling indicated that essentially all of the MTBE should have dissolved into the matrix. In contrast, essentially all of the isooctane should have remained in the LNAPL in the fractures.

Johnson, R.L.; Grady, D.E. [Oregon Graduate Institute, Portland, OR (United States); Walden, T. [BP Oil Europe, Brussels (Belgium)

1997-12-31T23:59:59.000Z

376

Analytical Methodologies for Detection of Gamma-Valerolactone, Delta-Valerolactone, Acephate and Azinphos Methyl and Their Associated Metabolites in Complex Biological Matrices  

SciTech Connect (OSTI)

Non-invasive biomonitoring for chemicals of interest in law enforcement and similar monitoring of pesticides, together with their metabolites, can not only save money but can lead to faster medical attention for individuals exposed to these chemicals. This study describes methods developed for the analysis of gamma-valerolactone (GVL), delta-valerolactone (DVL), acephate, and azinphos methyl in saliva and serum. Liquid chromatography/mass spectrometry (LC/MS) operated in the negative and positive ion mode and gas chromatography/mass spectrometry (GC/MS) were used to analyze GVL and DVL. Although both analytical techniques worked well, lower detection limits were obtained with GC/MS. The lactones and their corresponding sodium salts were spiked into both saliva and serum. The lactones were isolated from saliva or serum using newly developed extraction techniques and then subsequently analyzed using GC/MS. The sodium salts of the lactones are nonvolatile and require derivatization prior to analysis by this method. N-methyl-N-(t-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA) was ultimately selected as the reagent for derivatization because the acidic conditions required for reactions with diazomethane caused the salts to undergo intramolecular cyclization to the corresponding lactones. In vitro studies were conducted using rat liver microsomes to determine other metabolites associated with these compounds. Azinphos methyl and acephate are classified as organophosphate pesticides, and are known to be cholinesterase inhibitors in humans and insects, causing neurotoxicity. For this reason they have both exposure and environmental impact implications. These compounds were spiked into serum and saliva and prepared for analysis by GC/MS. Continuation of this research would include analysis by GC/MS under positive ion mode to determine the parent ions of the unknown metabolites. Further research is planned through an in vivo analysis of the lactones and pesticides. These methodologies could be extended for further analysis of other similar compounds.

Zink, E.; Clark, R.; Grant, K.; Campbell, J.; Hoppe, E.

2005-01-01T23:59:59.000Z

377

Controlling DNA Methylation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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378

Dissociation of internal energy-selected methyl bromide ion revealed from threshold photoelectron-photoion coincidence velocity imaging  

SciTech Connect (OSTI)

Dissociative photoionization of methyl bromide (CH{sub 3}Br) in an excitation energy range of 10.45–16.90 eV has been investigated by using threshold photoelectron-photoion coincidence (TPEPICO) velocity imaging. The coincident time-of-flight mass spectra indicate that the ground state X{sup 2}E of CH{sub 3}Br{sup +} is stable, and both A{sup 2}A{sub 1} and B{sup 2}E ionic excited states are fully dissociative to produce the unique fragment ion of CH{sub 3}{sup +}. From TPEPICO 3D time-sliced velocity images of CH{sub 3}{sup +} dissociated from specific state-selected CH{sub 3}Br{sup +} ion, kinetic energy release distribution (KERD) and angular distribution of CH{sub 3}{sup +} fragment ion are directly obtained. Both spin-orbit states of Br({sup 2}P) atom can be clearly observed in fast dissociation of CH{sub 3}Br{sup +}(A{sup 2}A{sub 1}) ion along C–Br rupture, while a KERD of Maxwell-Boltzmann profile is obtained in dissociation of CH{sub 3}Br{sup +}(B{sup 2}E) ion. With the aid of the re-calculated potential energy curves of CH{sub 3}Br{sup +} including spin-orbit coupling, dissociation mechanisms of CH{sub 3}Br{sup +} ion in A{sup 2}A{sub 1} and B{sup 2}E states along C–Br rupture are revealed. For CH{sub 3}Br{sup +}(A{sup 2}A{sub 1}) ion, the CH{sub 3}{sup +} + Br({sup 2}P{sub 1/2}) channel is occurred via an adiabatic dissociation by vibration, while the Br({sup 2}P{sub 3/2}) formation is through vibronic coupling to the high vibrational level of X{sup 2}E state followed by rapid dissociation. C–Br bond breaking of CH{sub 3}Br{sup +}(B{sup 2}E) ion can occur via slow internal conversion to the excited vibrational level of the lower electronic states and then dissociation.

Tang, Xiaofeng [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China) [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Zhou, Xiaoguo, E-mail: xzhou@ustc.edu.cn, E-mail: yanbing@jlu.edu.cn; Liu, Shilin [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China) [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Sun, Zhongfa [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China)] [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Liu, Fuyi; Sheng, Liusi [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China)] [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Yan, Bing, E-mail: xzhou@ustc.edu.cn, E-mail: yanbing@jlu.edu.cn [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China)] [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China)

2014-01-28T23:59:59.000Z

379

Properties of electrospun CdS and CdSe filled poly(methyl methacrylate) (PMMA) nanofibres  

SciTech Connect (OSTI)

Graphical abstract: SEM images of CdS/PMMA showing coiling as loading of CdS nanoparticles is increased. Thermal stability is increased with increase in %loading of both CdS and CdSe nanoparticles. Research highlights: {yields} TOPO-capped CdS and HDA-capped CdSe nanoparticles were synthesized and fully characterized. {yields} The nanoparticles were mixed with the polymer, PMMA using electrospinning technique using 2, 5 and 10% weight loadings. {yields} The mixture was spun to produce fibres with optical and thermal properties showing significant change and also the increase in loading causing bending or spiraling. {yields} Both TEM images for nanoparticles and SEM for fibres shows the morphology and sizes of the particles. -- Abstract: Electrospinning technique was used to fabricate poly(methyl methacrylate) (PMMA) fibres incorporating CdS and CdSe quantum dots (nanoparticles). Different nanoparticle loadings (2, 5 and 10 wt% with respect to PMMA) were used and the effect of the quantum dots on the properties of the fibres was studied. The optical properties of the hybrid composite fibres were investigated by photoluminescence and UV-vis spectrophotometry. Scanning electron microscopy (SEM), X-ray diffraction and FTIR spectrophotometry were also used to investigate the morphology and structure of the fibres. The optical studies showed that the size-tunable optical properties can be achieved in the polymer fibres by addition of quantum dots. SEM images showed that the morphologies of the fibres were dependent on the added amounts of quantum dots. A spiral type of morphology was observed with an increase in the concentration of CdS and CdSe nanoparticles. Less beaded structures and bigger diameter fibres were obtained at higher quantum dot concentrations. X-ray diffractometry detected the amorphous peaks of the polymer and even after the quantum dots were added and the FTIR analysis shows that there was no considerable interaction between the quantum dots and the polymer fibres at low concentration of quantum dots however at higher concentrations some interactions were observed which shows that QDs were present on the surfaces of the fibres.

Mthethwa, T.P. [University of Johannesburg, Department of Chemical Technology, P.O. Box 17011, Doornfontein 2028 (South Africa)] [University of Johannesburg, Department of Chemical Technology, P.O. Box 17011, Doornfontein 2028 (South Africa); Moloto, M.J., E-mail: mmoloto@uj.ac.za [University of Johannesburg, Department of Chemical Technology, P.O. Box 17011, Doornfontein 2028 (South Africa); De Vries, A.; Matabola, K.P. [CSIR Materials Science and Manufacturing, 4 Gomery avenue, Summerstrand, Port Elizabeth 6000 (South Africa)] [CSIR Materials Science and Manufacturing, 4 Gomery avenue, Summerstrand, Port Elizabeth 6000 (South Africa)

2011-04-15T23:59:59.000Z

380

Electronic and optical response of Ru(II) complexes functionalized by methyl, carboxylate groups: joint theoretical and experimental study  

SciTech Connect (OSTI)

New photovoltaic and photocatalysis applications have been recently proposed based on the hybrid Ru(II)-bipyridine-complex/semiconductor quantum dot systems. In order to attach the complex to the surface of a semiconductor, a linking bridge - a carboxyl group - is added to one or two of the 2,2{prime}-bipyridine ligands. Such changes in the ligand structure, indeed, affect electronic and optical properties and consequently, the charge transfer reactivity of Ru-systems. In this study, we apply both theoretical and experimental approaches to analyze the effects brought by functionalization of bipyridine ligands with the methyl, carboxyl, and carboxilate groups on the electronic structure and optical response of the Ru(II) bipyridine complex. First principle calculations based on density functional theory (DFT) and linear response time dependent density functional theory (TDDFT) are used to simulate the ground and excited-state structures of functionalized Ru-complexes in the gas phase, as well as in acetonitrile solution. In addition, an inelaborate Frenkel exciton model is used to explain the optical activity and splitting patterns of the low-energy excited states. All theoretical results nicely complement experimental absorption spectra of Ru-complexes and contribute to their interpretation. We found that the carboxyl group breaks the degeneracy of two low-energy optically bright excited states and red-shifts the absorption spectrum, while leaves ionization and affinity energies of complexes almost unchanged. Experimental studies show a high probability of deprotonation of the carbboxyl group in the Ru-complexes resulted in a slight blue shift and decrease of intensities of the low energy absorption peaks. Comparison of experimental and theoretical linear response spectra of deprotanated complexes demonstrate strong agreement when acetonitrile solvent is used in simulations. A polar solvent is found to play an important role in calculations of optical spectra: it stabilizes the energy of states localized on the carboxyl or carboxylate groups eliminating artificial charge transport states, which typically appear in TDDFT calculations. Thus, it is validated that the excited-state structure of the functionalized Ru-complexes, specifically in the case of the deprotonated functions, can be accurately modeled by TDDFT with the addition of a dielectric continuum in simulations.

Tretiak, Sergei [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

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381

Murine T cell activation is regulated by surfen (bis-2-methyl-4-amino-quinolyl-6-carbamide)  

SciTech Connect (OSTI)

Highlights: •Surfen is the first inhibitor of glycosaminoglycan function to be studied in murine T cells. •Surfen reduces T cell proliferation stimulated in vitro and in vivo. •Surfen reduces CD25 expression in T cells activated in vivo but not in vitro. •Surfen increases T cell proliferation when T cell receptor activation is bypassed. •Surfen’s effects are blocked by co-administration of heparin sulfate. -- Abstract: Surfen (bis-2-methyl-4-amino-quinolyl-6-carbamide) binds to glycosaminoglycans (GAGs) and has been shown to influence their function, and the function of proteoglycans (complexes of GAGs linked to a core protein). T cells synthesize, secrete and express GAGs and proteoglycans which are involved in several aspects of T cell function. However, there are as yet no studies on the effect of GAG-binding agents such as surfen on T cell function. In this study, surfen was found to influence murine T cell activation. Doses between 2.5 and 20 ?M produced a graduated reduction in the proliferation of T cells activated with anti-CD3/CD28 antibody-coated T cell expander beads. Surfen (20 mg/kg) was also administered to mice treated with anti-CD3 antibody to activate T cells in vivo. Lymphocytes from surfen-treated mice also showed reduced proliferation and lymph node cell counts were reduced. Surfen reduced labeling with a cell viability marker (7-ADD) but to a much lower extent than its effect on proliferation. Surfen also reduced CD25 (the ?-subunit of the interleukin (IL)-2 receptor) expression with no effect on CD69 expression in T cells treated in vivo but not in vitro. When receptor activation was bypassed by treating T cells in vitro with phorbyl myristate acetate (10 ng/ml) and ionomycin (100 ng/ml), surfen treatment either increased proliferation (10 ?M) or had no effect (2.5, 5 and 20 ?M). In vitro treatment of T cells with surfen had no effect on IL-2 or interferon-? synthesis and did not alter proliferation of the IL-2 dependent cell line CTLL-2. The effect of surfen was antagonized dose-dependently by co-treatment with heparin sulfate. We conclude that surfen inhibits T cell proliferation in vitro and in vivo. When T cell receptor-driven activation is bypassed surfen had a neutral or stimulatory effect on T cell proliferation. The results imply that endogenous GAGs and proteoglycans play a complex role in promoting or inhibiting different aspects of T cell activation.

Warford, Jordan, E-mail: jordan.warford@dal.ca [Department of Pathology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada)] [Department of Pathology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Doucette, Carolyn D., E-mail: carolyn.doucette@dal.ca [Department of Microbiology and Immunology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Hoskin, David W., E-mail: d.w.hoskin@dal.ca [Department of Pathology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Microbiology and Immunology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Easton, Alexander S., E-mail: alexander.easton@dal.ca [Department of Pathology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Microbiology and Immunology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Surgery (Neurosurgery), Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada)

2014-01-10T23:59:59.000Z

382

Possible modulation of N-methyl-D,L-aspartic acid induced prolactin release by testicular steroids in the adult male rhesus monkey  

SciTech Connect (OSTI)

N-methyl-D,L-aspartic acid (NMA), an agonist of the neurotransmitter glutamate has been shown to acutely stimulate the release of prolactin (PRL) in intact rats and monkeys. To further investigate the role of neuroexcitatory amino acids in PRL secretion, the effects of NMA administration were examined on PRL release in long term orchidectomized adult rhesus monkeys, in both the absence and presence of testosterone. Intact and long term castrated adult male monkeys weighing between 8-13 kg, were implanted with a catheter via the saphenous vein for blood withdrawal and drug infusion. Blood samples were collected at 10 min intervals for 50 min before and 70 min after administration of the drug or vehicle. Plasma PRL concentrations were estimated using radioimmunoassay. Whereas a single iv injection of NMA induced a prompt discharge of PRL in intact monkeys, an identical dose had surprisingly no effect on PRL secretion in orchidectomized animals. On the other hand, plasma PRL increases in response to a challenge dose of thyrotropin releasing hormone were similar in magnitude in the two groups of monkeys. Testosterone replacement in orchidectomized animals by parenteral administration of testosterone enanthate reinitiated the PRL responsiveness to acute NMA stimulation. These results indicate that N-methyl-D-aspartic acid (NMDA) dependent drive to PRL release in the adult male rhesus monkey may be overtly influenced by the sex steroid milieu.

Arslan, M.; Rizvi, S.S.R.; Jahan, S.; Zaidi, P.; Shahab, M. (Quaid-i-Azam Univ., Islamabad (Pakistan))

1991-01-01T23:59:59.000Z

383

Synthesis of 6-Methyl-9-propyldibenzothiophene-4-ol amended to 9-isopropyl-6-methyldibenzothiophene-4-ol. Final technical report, July 25, 1991--January 25, 1993  

SciTech Connect (OSTI)

This is a draft final technical report on Task 1 of a contract to synthesize 6-Methyl-9-propyldibenzothiophene-4-ol, as amended to 9- isopropyl-6-methyldibenzothiophene-4-ol. This report is a compilation of data presented in earlier reports. The first annual report dealt with an attempted synthesis of 4-methoxy-6-methyl-9- propyldibenzothiophene (the original target compound), the successful synthesis and delivery of 200 grams of the sulfide 1,4-diethyl-2- [(2{prime}-methoxyphenyl)-thio]benzene, and initial work on a new synthesis route for the preparation of the new target compound 9- isopropyl-6-methyldibenzothiophene-4-ol. The change to the new target compound and the new synthesis route became necessary when it was learned that the sulfide mixture could not be cyclized to the substituted dibenzothiophene mixture. The second annual report described the successful preparation of 45 g of the new target compound using the new synthesis route. Subsequently funds were provided to synthesize an additional 45 g of the new target using the same reaction scheme. This task was recently completed.

Eisenbraun, E.J.

1992-02-17T23:59:59.000Z

384

(S)-4-Trimethylsilyl-3-butyn-2-ol as an auxiliary for stereocontrolled synthesis of salinosporamide analogs with modifications at positions  

E-Print Network [OSTI]

(S)-4-Trimethylsilyl-3-butyn-2-ol as an auxiliary for stereocontrolled synthesis of salinosporamide a diastereoselective Mukaiyama aldol reaction between the chi- ral 5-tert-butyldimethylsiloxy-3-methyl-1H-pyrrole-2 synthesis of salinos- poramide analogs with structural variations at positions C2 and C5. The key step

385

Synthesis and characterization of redox polymers of (M(4-vinyl-4 prime -methyl-2,2 prime -bipyridine) sub 3 )(PF sub 6 ) sub 2 (M = Ru, Os)  

SciTech Connect (OSTI)

The authors have prepared polymers of (M(vbpy){sub 3}(PF{sub 6}){sub 2}) (M = Ru, Os) (vbpy = 4-vinyl-4{prime}-methyl-2,2{prime}-bipyridine) in solution via free-radical polymerization and fractionated them according to molecular weight using size exclusion chromatography. Different fractions have been characterized by electrochemical and spectroscopic means. The authors find that whereas for the osmium containing polymers the relative polymer size varies in proportion to the number of vinyl groups consumed during the polymerization reaction, the same is not true for the analogous ruthenium polymers. In addition, the emission energy of both the ruthenium and osmium polymers is also related to the concentration of residual vinyl groups in the polymer. Upon polymerization, there is a shift in the emission toward higher energies. Electrochemically determined diffusion coefficients are consistent with the relative size of the various fractions.

Bommarito, S.L.; Lowery-Bretz, S.P.; Abruna, H.D. (Cornell Univ., Ithaca, NY (United States))

1992-02-05T23:59:59.000Z

386

Synthesis and characterization of redox copolymers of (Ru(4-vinyl-4 prime -methyl-2,2 prime -bipyridine) sub 3 ) sup 2+ and (Os(4-vinyl-4 prime -methyl-2,2 prime -bipyridine) sub 3 ) sup 2+ : Unusual energy-transfer dynamics  

SciTech Connect (OSTI)

Copolymers of (Ru(vbpy){sub 3}(PF{sub 6}){sub 2}) and (Os(vbpy){sub 3}(PF{sub 6}){sub 2}) (vbpy = 4-vinyl-4{prime}-methyl-2,2{prime}-bipyridine) have been prepared in solution and by electropolymerization. The ruthenium and osmium monomers were incorporated in the copolymers in different ratios depending on the polymerization method. These results point to fundamental differences between solution polymerization and electropolymerization. In addition, luminescence experiments at liquid-nitrogen temperature and room temperature point to a significant degree of energy transfer from ruthenium to osmium states in the polymer.

Bommarito, S.L.; Lowery-Bretz, S.P.; Abruna, H.D. (Cornell Univ., Ithaca, NY (United States))

1992-02-05T23:59:59.000Z

387

Methyl chloride via oxyhydrochlorination of methane: A building block for chemicals and fuels from natural gas. Quarterly technical progress report No. 01, September 30, 1996--December 31, 1996  

SciTech Connect (OSTI)

The objectives of this cooperative agreement are to develop the oxyhydrochlorination (OHC) process for the conversion of methane to methyl chloride. In the first Phase of the project, Dow Corning has developed a stable selective catalyst and demonstrated the technology on a laboratory and a pilot plant scale. Specific tasks to achieve these objectives have been developed as follows: TASK 1 Fundamental Technical and Economic Evaluation TASK 2 Catalyst Selection Optimization and Characterization Studies TASK 3 Pilot Plant Design TASK 4 Pilot Plant Detailed Engineering, Procurement and Construction TASK 5 Pilot Plant Startup and Operation TASK 6 Pilot Plant Process Optimization TASK 7 Pilot Plant Extended Operation TASK 8 Pilot Plant Economic Evaluation/Scale-up Decision Significant progress has been completed in Task 1 with the objective to complete a fundamental technical and economic evaluation of learning gathered the Phase I effort of this project. A decision to proceed with the project will be made after completion of this Task. A computer model of the reactor system has been developed, which includes heat and mass transfer effects as well as reactions. Model validation is in progress. The Absorber/Stripper technology evaluated and implemented on the Phase I PDU to recover chlorocarbons (including methyl chloride) from reaction products has been scaled to evaluate economics for a commercial scale plant. In a parallel exercise, alternate recovery technologies were investigated for economic evaluation, to assure that the minimum capital option is pursued for the Phase II design. Commercial scale plant equipment and total plant costs are being evaluated using information from the Phase I PDU, reactor modeling and recovery system evaluation to estimate capital and operating costs for a commercial scale OHC unit.

Wineland, J.

1997-01-16T23:59:59.000Z

388

Pharmacological characterization of LY233053: A structurally novel tetrazole-substituted competitive N-methyl-D-aspartic acid antagonist with a short duration of action  

SciTech Connect (OSTI)

This study reports the activity of a structurally novel excitatory amino acid receptor antagonist, LY233053 (cis-(+-)-4-((2H-tetrazol-5-yl)methyl)piperidine-2-carboxylic acid), the first tetrazole-containing competitive N-methyl-D-aspartic acid (NMDA) antagonist. LY233053 potently inhibited NMDA receptor binding to rat brain membranes as shown by the in vitro displacement of (3H) CGS19755 (IC50 = 107 +/- 7 nM). No appreciable affinity in (3H)alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) or (3H)kainate binding assays was observed (IC50 values greater than 10,000 nM). In vitro NMDA receptor antagonist activity was further demonstrated by selective inhibition of NMDA-induced depolarization in cortical wedges (IC50 = 4.2 +/- 0.4 microM vs. 40 microM NMDA). LY233053 was effective after in vivo systemic administration in a number of animal models. In neonatal rats, LY233053 selectively blocked NMDA-induced convulsions (ED50 = 14.5 mg/kg i.p.) with a relatively short duration of action (2-4 hr). In pigeons, LY233053 potently antagonized (ED50 = 1.3 mg/kg i.m.) the behavioral suppressant effects of 10 mg/kg of NMDA. However, a dose of 160 mg/kg, i.m., was required to produce phencyclidine-like catalepsy in pigeons. In mice, LY233053 protected against maximal electroshock-induced seizures at lower doses (ED50 = 19.9 mg/kg i.p.) than those that impaired horizontal screen performance (ED50 = 40.9 mg/kg i.p.). Cholinergic and GABAergic neuronal degenerations after striatal infusion of NMDA were prevented by single or multiple i.p. doses of LY233053. In summary, the antagonist activity of LY233053 after systemic administration demonstrates potential therapeutic value in conditions of neuronal cell loss due to NMDA receptor excitotoxicity.

Schoepp, D.D.; Ornstein, P.L.; Leander, J.D.; Lodge, D.; Salhoff, C.R.; Zeman, S.; Zimmerman, D.M. (Eli Lilly and Company, Indianapolis, IN (USA))

1990-12-01T23:59:59.000Z

389

Correlation of hetorogeneous blood flow and uptake of a di-methyl-branched IODO fatty acid in the normal and ischemic dog heart  

SciTech Connect (OSTI)

Myocardial blood flow (MBF) is heterogeneously distributed in normal and ischemic myocardium (myoc). Methylated iodinated fatty acids, like 15-(p-I-125-iodophenyl)-3,3-dimethylpentadecanoic acid (DMIPPA) can be used to study fatty acid metabolism with SPECT. We studied the relationship between DMIPPA uptake and MBF. In 10 open-chest dogs, ischemica was induced in the LAD coronary artery by an extra-corporal bypass system. MBF was measured with Sc-46 labeled microspheres. Fourty min. after DMIPPA iv. (34{plus_minus}4 MBq), hearts were excised and left ventricles were cut into 120 pieces, weighed and radioactivities counted. MBF and DMIPPA uptake were determined by counting in normal and ischemic myoc. Heterogeneity is expressed as the coefficient of variation (CV) and agreement as the CV of the DMIPPA uptake to MBF ratio. A control study, normal flow in LAD, in 4 dogs revealed no differences in MBF or DMIPPA uptake between the cannulated versus native perfused myoc. We conclude the DMIPPA detects ischemia, in which it shows a different relation with MBF compared to normal myoc. DMIPPA is less heterogeneously distributed than MBF and agreement between MFB and DMIPPA uptake decreases during ischemia.

Sloof, G.W.; Visser, F.C.; Comans, E.F.I. [Free Univ. Hospital, Amsterdam (Netherlands)]|[Oak Ridge National Lab., TN (United States)] [and others

1995-05-01T23:59:59.000Z

390

Scanning tunneling microscopy of dimeric and polymeric products of electroreduced (Re(CO) sub 3 (4-vinyl,4 prime -methyl-2,2 prime -bipyridine)Cl)  

SciTech Connect (OSTI)

Scanning tunneling microscopy (STM) was used to image adsorbed products resulting from electroreduction of (Re(CO){sub 3}(vbpy)Cl) (vbpy = 4-vinyl,4{prime}-methyl-2,2{prime}-bipyridine) on highly oriented pyrolytic graphite (HOPG). STM images, in air, of HOPG electrodes following electroreduction of (Re(CO){sub 3}(vbpy)Cl) (in acetonitrile/0.1 M tetra-n-butylammonium perchlorate) by cycling the potential between 0 and {minus}2.0 V vs a sodium saturated colomel electrode (SSCE) show molecular species uniformly distributed on the surface including approximately dumbbell shaped molecules ({approx} 40 {times} 20 {angstrom}). The size and shape of these aggregates is consistent with products derived from vinyl-vinvyl coupling of Re-Re bonded dimers: ((vbpy)(CO){sub 3}Re-Re(CO){sub 3}(vbpyH-vbpyH)(CO){sub 3}Re-Re(CO){sub 3}(vbpy)). STM images of electrodes prepared by cycling the potential between 0 and {minus}1.45 V vs SSCE (less reducing conditions) show highly nonuniform coating of the surface by polymer. Several polymer morphologies were observed with polymer nucleation preferentially occurring at step sites on HOPG.

Snyder, S.R.; White, H.S. (Univ. of Minnesota, Minneapolis (USA)); Lopez, S.; Abruna, H.D. (Cornell Univ., Ithaca, NY (USA))

1990-02-14T23:59:59.000Z

391

Rotational spectroscopy as a tool to investigate interactions between vibrational polyads in symmetric top molecules: low-lying states v8 <= 2 of methyl cyanide, CH$_3$CN  

E-Print Network [OSTI]

Spectra of methyl cyanide were recorded to analyze interactions in low-lying vibrational states and to construct line lists for radio astronomical observations as well as for infrared spectroscopic investigations of planetary atmospheres. The rotational spectra cover large portions of the 36-1627 GHz region. In the infrared (IR), a spectrum was recorded for this study in the region of 2nu8 around 717 cm-1 with assignments covering 684-765 cm-1. Additional spectra in the nu8 region were used to validate the analysis. The large amount and the high accuracy of the rotational data extend to much higher J and K quantum numbers and allowed us to investigate for the first time in depth local interactions between these states which occur at high K values. In particular, we have detected several interactions between v8 = 1 and 2. Notably, there is a strong Delta(v8) = +- 1, Delta(K) = 0, Delta(l) = +-3 Fermi resonance between v8 = 1^-1 and v8 = 2^+2 at K = 14. Pronounced effects in the spectrum are also caused by reso...

Müller, Holger S P; Drouin, Brian J; Pearson, John C; Kleiner, Isabelle; Sams, Robert L; Sung, Keeyoon; Ordu, Matthias H; Lewen, Frank

2015-01-01T23:59:59.000Z

392

Alpha and recoil track detection in poly(methyl methacrylate) (PMMA)—Towards a method for in vitro assessment of radiopharmaceuticals internalized in cancer cells  

SciTech Connect (OSTI)

A method for detection and characterization of single MeV ?-particle and recoil tracks in PMMA photoresist by atomic force microscopy (AFM) analysis has been demonstrated. The energy deposition along the track is shown to lead to a latent pattern in the resist due to contrast reversal. It has been shown that the pattern, consisting of conical spikes, can be developed by conventional processing as a result of the dissolution rate of poly(methyl methacrylate) (PMMA) being greater than that for the modified material in the cylindrical volume of the track core. The spikes can be imaged and counted by routine AFM analysis. Investigations by angular-resolved near-grazing incidence reveal additional tracks that correspond to recoil tracks. The observations have been correlated with modelling, and shown to be in qualitative agreement with prevailing descriptions of collision cascades. The results may be relevant to technologies that are based on detection and characterization of single energetic ions. In particular, the direct visualization of the collision cascade may allow more accurate estimates of the actual interaction volume, which in turn will permit more precise assessment of dose distribution of ?-emitting radionuclides used for targeted radiotherapy. The results could also be relevant to other diagnostic or process technologies based on interaction of energetic ions with matter.

Myhra, S., E-mail: sverre.myhra@materials.ox.ac.uk; Chakalova, R. [Oxford University Begbroke Science Park, University of Oxford, Oxford (United Kingdom)] [Oxford University Begbroke Science Park, University of Oxford, Oxford (United Kingdom); Falzone, N. [MRC/CRUK Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, United Kingdom and Department of Biomedical Science, Tshwane University of Technology, Pretoria (South Africa)] [MRC/CRUK Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, United Kingdom and Department of Biomedical Science, Tshwane University of Technology, Pretoria (South Africa)

2014-03-15T23:59:59.000Z

393

Pump-beam-induced optical damage depended on repetition frequency and pulse width in 4-dimethylamino-N Prime -methyl-4 Prime -stilbazolium tosylate crystal  

SciTech Connect (OSTI)

We investigated the dependence of optical damage to an organic nonlinear optical crystal of 4-dimethylamino-N Prime -methyl-4 Prime -stilbazolium tosylate (DAST) on the repetition frequency and pulse width of the pump beam used to cause the thermal damage. For a pump beam with a pulse width of 15 ns at a wavelength of 1064 nm, the highest damage threshold of 8.0 J/cm{sup 2} was measured for repetition frequencies in the range from 10 to 40 Hz. On the other hand, DAST crystals were easily damaged under the repetition rates from 50 to 100 Hz. For 600-ps pulses, a higher damage threshold that was a factor of 11 to 28 times higher in terms of peak intensity was obtained compared with that of 15-ns pulses. In both the cases of 15-ns pulse duration and 600-ps duration, we demonstrated that the thermal effects in DAST crystals dominated the optical damage, which depended on thermal accumulation and dissipation.

Matsukawa, Takeshi; Nawata, Kouji; Notake, Takashi; Qi Feng; Kawamata, Hiroshi; Minamide, Hiroaki [Tera-photonics Laboratory, RIKEN, 519-1399, Aramaki-Aoba, Aoba-ku, Sendai 980-0845 (Japan)

2013-07-08T23:59:59.000Z

394

The design of new ligands and transition metal compounds for the oxidation of organic compounds  

E-Print Network [OSTI]

dehydrated by heating under dynamic vacuum at 150?C for 3 hours. The anhydrous materials were stored in a dry box under nitrogen. (R)-binaphthol was obtained from ABCR Chemical and 3,5-di-tert-butyl salicylaldehyde was obtained from Advanced Asymmetrics.... All other reagents were used as received. All NMR chemical shifts are given in ppm and were recorded on a Mercury-300BB spectrometer ( 1 H, 299.91 MHz; 13 C { 1 H} 75.41 MHz) using the solvent as an internal standard (CDCl 3 (or residual CHCl 3...

Grill, Joseph Michael

2009-06-02T23:59:59.000Z

395

An investigation of the burning rates of thin films of some selected composite propellants  

E-Print Network [OSTI]

Ammoni a/Perch 1 ori c Aci d Aluminum Atmospheres butyl Acetate Carbon Glass Cyclo tetramethylenetetrani tr amine L ad Azide IicCormick-Selph Methyl Fthyl Ketone IIitrocelIulose Oxidizer/Fue'I x-104, x-164 NcCormick-Selph material 300, 104...

Sawyer, Miles Lee

1970-01-01T23:59:59.000Z

396

Motor Gasoline Outlook and State MTBE Bans  

Reports and Publications (EIA)

The U.S. is beginning the summer 2003 driving season with lower gasoline inventories and higher prices than last year. Recovery from this tight gasoline market could be made more difficult by impending state bans on the blending of methyl tertiary butyl ether (MTBE) into gasoline that are scheduled to begin later this year.

2003-01-01T23:59:59.000Z

397

untitled  

Gasoline and Diesel Fuel Update (EIA)

3,054 Fuel Ethanol (FE) 1,019 97 1,116 2,133 528 393 3,054 Methyl Tertiary Butyl Ether (MTBE) 561 0 561 0 0 0 0 All Other Oxygenates a 0 0 0 0 0 0 0 Motor Gasoline Blend. Comp....

398

PSA Vol 1 Tables Revised Ver 2 Print.xls  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

11,352 13 1,309 15,181 42 Fuel Ethanol (FE) 0 0 0 0 0 0 0 Methyl Tertiary Butyl Ether (MTBE) 234 928 10,251 0 21 11,434 31 Other Oxygenates 955 390 1,101 13 1,288 3,747 10 Motor...

399

I. Pt-Catalyzed Tandem Epoxide Fragmentation/Pentannulation of Propargylic Esters II. Progress Toward the Kopsia Family of Indole Alkaloids  

E-Print Network [OSTI]

methyl t-butyl ether (MTBE), a much more environmentallyPhMe, reflux POCl 3 , Et 3 N CN MTBE Scheme 3.3: OptimizedO H NH POCl 3 , Et 3 N CN MTBE 1-Isocyanocyclohex-1-ene (

Pujanauski, Brian Gerard

2010-01-01T23:59:59.000Z

400

UMass builds bugs to eat MTBE ByAuriaCimino  

E-Print Network [OSTI]

UMass builds bugs to eat MTBE ByAuriaCimino STAfFWRITER An area university's process to destroy with methyl tertiary butyl ether (MTBE), which is found in gasoline. Once the first field trial is complete in particular has suffered from MTBE contamination because of the abundance of groundwater in the state, said

Lovley, Derek

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

untitled  

Gasoline and Diesel Fuel Update (EIA)

Fuel Ethanol (FE) 1,229 108 1,337 2,369 724 497 3,590 Methyl Tertiary Butyl Ether (MTBE) 292 0 292 0 0 0 0 All Other Oxygenates a 0 0 0 0 0 0 0 Motor Gasoline Blend. Comp....

402

Simultaneous Efficiency, NOx, and Smoke Improvements through Diesel/Gasoline Dual-Fuel Operation in a Diesel Engine  

E-Print Network [OSTI]

or liquefied petroleum gas, natural gas, biogas, hydrogen, and alcohols such as methanol, ethanol, iso-propanol, and n-butanol), and fuel additives (MTBE or methyl tertiary-butyl ether, H2O2 or hydrogen peroxide, 2-EHN or ethylhexyl nitrate and DTBP or di...

Sun, Jiafeng

2014-08-05T23:59:59.000Z

403

Acute effects of a sarin-like organophosphorus agent, bis(isopropyl methyl)phosphonate, on cardiovascular parameters in anaesthetized, artificially ventilated rats  

SciTech Connect (OSTI)

The organophosphorus compound sarin irreversibly inhibits acetylcholinesterase. We examined the acute cardiovascular effects of a sarin-like organophosphorus agent, bis(isopropyl methyl)phosphonate (BIMP), in anaesthetized, artificially ventilated rats. Intravenous administration of BIMP (0.8 mg/kg; the LD50 value) induced a long-lasting increase in blood pressure and tended to increase heart rate. In rats pretreated with the non-selective muscarinic-receptor antagonist atropine, BIMP significantly increased both heart rate and blood pressure. In atropine-treated rats, hexamethonium (antagonist of ganglionic nicotinic receptors) greatly attenuated the BIMP-induced increase in blood pressure without changing the BIMP-induced increase in heart rate. In rats treated with atropine plus hexamethonium, intravenous phentolamine (non-selective ?-adrenergic receptor antagonist) plus propranolol (non-selective ?-adrenergic receptor antagonist) completely blocked the BIMP-induced increases in blood pressure and heart rate. In atropine-treated rats, the reversible acetylcholinesterase inhibitor neostigmine (1 mg/kg) induced a transient increase in blood pressure, but had no effect on heart rate. These results suggest that in anaesthetized rats, BIMP induces powerful stimulation of sympathetic as well as parasympathetic nerves and thereby modulates heart rate and blood pressure. They may also indicate that an action independent of acetylcholinesterase inhibition contributes to the acute cardiovascular responses induced by BIMP. - Highlights: • A sarin-like agent BIMP markedly increased blood pressure in anaesthetized rats. • Muscarinic receptor blockade enhanced the BIMP-induced increase in blood pressure. • Ganglionic nicotinic receptor blockade attenuated the BIMP-induced response. • Blockade of ?- as well as ?-receptors attenuated the BIMP-induced response.

Watanabe, Yoshimasa [Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Itoh, Takeo, E-mail: titoh@med.nagoya-cu.ac.jp [Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Shiraishi, Hiroaki [Department of Forensic Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Maeno, Yoshitaka [Department of Forensic Medical Science, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Arima, Yosuke; Torikoshi, Aiko; Namera, Akira [Department of Forensic Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Makita, Ryosuke [Department of Nursing, Faculty of Health Sciences, Hiroshima Cosmopolitan University, Hiroshima (Japan); Yoshizumi, Masao [Department of Cardiovascular Physiology and Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Nagao, Masataka [Department of Forensic Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan)

2013-10-01T23:59:59.000Z

404

Electrochemistry and photocurrents of the tris(bipyridine)ruthenium(II) and methyl viologen cations immobilized in carrageenan hydrogel. [tris(2,2'-bipyridine)ruthenium(II)  

SciTech Connect (OSTI)

A procedure for immobilization of both a photochromophore, tris(2,2{prime}-bipyridine)ruthenium(II) (Ru(bpy){sub 3}{sup 2+}), and a quencher, methyl viologen (MV{sup 2+}), within a carrageenan hydrogel matrix at an electrode surface is described. Ru(bpy){sub 3}{sup 2+} and MV{sup 2+} exhibited diffusion coefficients that ranged from 10{sup {minus} 7} to 10{sup {minus} 6} cm{sup 2}/s in the hydrogel, which represents an improvement over other immobilization matrices. Photolysis of the resulting hydrogel surface modified electrodes gave rise to a significant photocurrent which depended on the concentrations of Ru(bpy){sub 3}{sup 2+}, MV{sup 2+}, and triethanolamine and resulted in a maximum value of 12 {mu}A/cm{sup 2} after the hydrogel was cured with a solution containing 5 mM Ru(bpy){sub 3}{sup 2+} and 50 mM MV{sup 2+}. The photocurrent was the result of reoxidation of MV{sup +} at the electrode surface following reduction of MV{sup 2+} by photoexcited Ru(bpy){sub 3}{sup 2+}. The quenching rate constant of Ru(bpy){sub 3}{sup 2+} by MV{sup 2+} in the hydrogel was 4.2 {times} 10{sup 8} M{sup {minus}1} s{sup {minus}1}. The photocurrent action spectrum was consistent with Ru(bpy){sub 3}{sup 2+} acting as the photochromophore. Offsetting the potential of the hydrogel electrode verified the role of the MV{sup 2+}/{sup +} redox couple as the source of the current.

Rillema, D.P.; Edwards, A.K. (Univ., of North Carolina, Charlotte (United States)); Perine, S.C.; Crumbliss, A.L. (Duke Univ., Durham, NC (United States))

1991-11-13T23:59:59.000Z

405

Photochemical generation of alkyl radicals and their reactions with methyl viologen radical cation and with transition-metal complexes in aqueous solution  

SciTech Connect (OSTI)

The irradiation of aqueous solutions of RCo((14)aneN{sub 4})(H{sub 2}O){sup 2+} (R = CH{sub 3}, C{sub 2}H{sub 5}, 1-C{sub 3}H{sub 7}, CH{sub 2}Cl, CH{sub 2}Br, CH{sub 2}OCH{sub 3}) with visible light, {lambda} {le} 400 nm, results in the homolysis of the cobalt-carbon bond. These complexes are quite unreactive toward a variety of dealkylating and redox reagents and thus represent a convenient source of small unstabilized carbon-centered radicals in the presence of potential substrates. The radicals react rapidly with the methyl viologen radical cation, k{sub MB} = (1-2) {times} 10{sup 9} M{sup {minus}1} s{sup {minus}1}. The kinetics of the formation of RCr{sup 2+} and RCo((14)aneN{sub 4})(H{sub 2}O){sup 2+} in the reactions of radicals with Cr{sup 2+} and Co((14)aneN{sub 4})(H{sub 2}O){sub 2}{sup 2+}, respectively, were studied by using MV{sup +} as a probe. The respective rate constants have values k{sub Cr} = (1.9-2.4) {times} 10{sup 8} M{sup {minus}1} s{sup {minus}1} and k{sub Co} = (1-2) {times} 10{sup 7} M{sup {minus}1} s{sup {minus}1} for all the radicals examined. 36 refs., 2 figs., 1 tab.

Bakac, A.; Espenson, J.H. (Iowa State Univ., Ames (USA))

1989-10-04T23:59:59.000Z

406

Broensted superacidity of HCl in a liquid chloroaluminate. AlCl sub 3 -1-ethyl-3-methyl-1H-imidazolium chloride  

SciTech Connect (OSTI)

The system HCl (0.1-1 atm)/AlCl{sub 3}-EMIC (55.0 mol % AlCl{sub 3}) (EMIC = 1-ethyl-3-methyl-1H-imidazolium chloride) at 23{degree}C is a Broensted superacid capable of protonating arenes to a degree similar to that of liquid HF at 0{degree}C (H{sub 0} = {minus}15.1). Arenes used in this investigation were biphenyl (I), naphthalene (II), 9H-fluorene (III), chrysene (IV), 2-methylnaphthalene (V), mesitylene (VI), pentamethylbenzene (VII), hexamethylbenzene (VIII), anthracene (IX), and 9,10-dimethylanthracene (X). In both the chloroaluminate melt and HF I is a weak base while VIII-X are strong bases. In between these extremes the order of basicities in both media is II < III and IV < V < VI < VII < VIII. A study of the effect of HCl partial pressure showed, for example that V is 50% protonated at 0.3 atm HCl. The overall reaction is arene + HCl + Al{sub 2}Cl{sub 7}{sup {minus}} {r reversible} arene {times} H{sup +} + 2AlCl{sub 4}{sup {minus}} and is reversible. The degree of protonation was measured by optical absorption spectrophotometry. The arenes are stable in the liquid chloroaluminate for many hours, and their protonated forms (arenium ions) are stable for 1 h or more. A new procedure for the preparation of EMIC was developed that yields exceptionally clean AlCl{sub 3}-EMIC melts with very low concentrations of protic and oxidizing impurities. 17 refs., 6 figs., 2 tabs.

Smith, G.P.; Dworkin, A.S.; Zingg, S.P. (Oak Ridge National Lab., TN (USA)); Pagni, R.M. (Univ. of Tennessee, Knoxville (USA))

1989-01-18T23:59:59.000Z

407

hTERT Extends the Life of Human Fibroblasts without Compromising Type I Interferon Signaling  

E-Print Network [OSTI]

Signaling PLOS ONE | www.plosone.org 6 March 2013 | Volume 8 | Issue 3 | e58233 We used infection by SeV, which is known to be a strong inducer of IFNs and other antiviral cytokines in human cells [69]. For this assay, media from uninfected and infected HEL... cells are placed onto na?¨ve Vero cells, which respond to but cannot produce IFN, and restrictions on VSV plaquing are monitored [70,71]. Media from mock-infected HEL cells had no effect on the ability of VSV to plaque on Vero cells while IFN...

Smith, Miles Christian; Goddard, Erica T.; Perusina Lafranca, Mirna; Davido, David J.

2013-03-05T23:59:59.000Z

408

active chemical 4-tert-pentylphenol: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

state synchronized to the flow for both types of reactions. For particles of finite size an emptying transition might also occur leading to no products left in the wake. Gy....

409

Middlesex FUSRAP Site - A Path to Site-Wide Closure - 13416  

SciTech Connect (OSTI)

The road-map to obtaining closure of the Middlesex Sampling Plant FUSRAP site in Middlesex, New Jersey (NJ) has required a multi-faceted approach, following the CERCLA Process. Since 1998, the US ACE, ECC, and other contractors have completed much of the work required for regulatory acceptance of site closure with unrestricted use. To date, three buildings have been decontaminated, demolished, and disposed of. Two interim storage piles have been removed and disposed of, followed by the additional removal and disposal of over 87,000 tons of radiologically and chemically-impacted subsurface soils by the summer of 2008. The US ACE received a determination from the EPA for the soils Operable Unit, (OU)-1, in September 2010 that the remedial excavations were acceptable, and meet the criteria for unrestricted use as required by the 2004 Record of Decision (ROD) for OU-1. Following the completion of OU-1, the project delivery team performed additional field investigation of the final Operable Unit for Middlesex, OU-2, Groundwater. As of December 2012, the project delivery team has completed a Supplemental Remedial Investigation, which will be followed with a streamlined Feasibility Study, Proposed Plan, and ROD. Several years of historical groundwater data was available from previous investigations and the FUSRAP Environmental Surveillance Program. Historical data indicated sporadic detections of Volatile Organic Compounds (VOCs), primarily trichloroethylene (TCE), carbon tetrachloride (CT), and methyl tert-butyl ether (MTBE), with no apparent trend or pattern indicating extent or source of the VOC impact. In 2008, the project delivery team initiated efforts to re-assess the Conceptual Site Model (CSM) for groundwater. The bedrock was re-evaluated as a leaky multi-unit aquifer, and a plan was developed for additional investigations for adequate bedrock characterization and delineation of groundwater contaminated primarily by CT, TCE, and tetrachloroethene (PCE). The investigation was designed to accumulate multiple lines of evidence to determine the source and to delineate the extent of contamination, as required to complete the CERCLA Process and gain regulatory acceptance. Investigative techniques included in-well vertical flow tracing, borehole geophysics and packer testing of temporary test holes to characterize contamination in the bedrock fractures beneath the site, and to delineate likely source areas. (authors)

Miller, David M. [ECC, 110 Fieldcrest Ave, Ste 31, Edison, NJ, 08837 (United States)] [ECC, 110 Fieldcrest Ave, Ste 31, Edison, NJ, 08837 (United States); Edge, Helen [US Army Corps of Engineers - NYD, 26 Federal Plaza, Room 1811, New York, NY, 10278 (United States)] [US Army Corps of Engineers - NYD, 26 Federal Plaza, Room 1811, New York, NY, 10278 (United States)

2013-07-01T23:59:59.000Z

410

California GAMA Program: Groundwater Ambient Monitoring and Assessment Results for the Sacramento Valley and Volcanic Provinces of Northern California  

SciTech Connect (OSTI)

In response to concerns expressed by the California Legislature and the citizenry of the State of California, the State Water Resources Control Board (SWRCB), implemented a program to assess groundwater quality, and provide a predictive capability for identifying areas that are vulnerable to contamination. The program was initiated in response to concern over public supply well closures due to contamination by chemicals such as methyl tert butyl ether (MTBE) from gasoline, and solvents from industrial operations. As a result of this increased awareness regarding groundwater quality, the Supplemental Report of the 1999 Budget Act mandated the SWRCB to develop a comprehensive ambient groundwater monitoring plan, and led to the initiation of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The primary objective of the California Aquifer Susceptibility (CAS) project (under the GAMA Program) is to assess water quality and to predict the relative susceptibility to contamination of groundwater resources throughout the state of California. Under the GAMA program, scientists from Lawrence Livermore National Laboratory (LLNL) collaborate with the SWRCB, the U.S. Geological Survey, the California Department of Health Services (DHS), and the California Department of Water Resources (DWR) to implement this groundwater assessment program. In 2003, LLNL carried out this vulnerability study in the Sacramento Valley and Volcanic Provinces. The goal of the study is to provide a probabilistic assessment of the relative vulnerability of groundwater used for the public water supply to contamination from surface sources. This assessment of relative contamination vulnerability is made based on the results of two types of analyses that are not routinely carried out at public water supply wells: ultra low-level measurement of volatile organic compounds (VOCs), and groundwater age dating (using the tritium-helium-3 method). In addition, stable oxygen isotope measurements help determine the recharge water source location. Interpreted together, and in the context of existing water quality and hydrogeologic data, these observable parameters help define the flow field of a groundwater basin, and indicate the degree of vertical communication between near-surface sources (or potential sources) of contamination, and deeper groundwater pumped at high capacity production wells.

Moran, J E; Hudson, G B; Eaton, G F; Leif, R

2005-01-20T23:59:59.000Z

411

Supramolecular Catalysis of Orthoformate Hydrolysis in Basic Solution: An Enzyme-Like Mechanism  

SciTech Connect (OSTI)

Magnetic susceptibility measurements and X-ray data confirm that tert-butyl substituted manganocenes [(Me{sub 3}C){sub n}C{sub 5}H{sub 5-n}]{sub 2}Mn (n= 1, 2) follow the trend previously observed with the methylated manganocenes, i.e., electron donating groups attached to the Cp ring stabilize the low-spin (LS) electronic ground state relative to Cp{sub 2}Mn and exhibit higher spin-crossover (SCO) temperatures. However, introducing three CMe3 groups on each ring gives a temperature invariant high-spin (HS) state manganocene. The origin of the high-spin state in [1,2,4-(Me{sub 3}C){sub 3}C{sub 5}H{sub 2}]{sub 2}Mn is due to the significant bulk of the [1,2,4-(Me{sub 3}C){sub 3}C{sub 5}H{sub 2}]{sup -} ligand, which is sufficient to generate severe inter-ring steric strain that prevents the realization of the low-spin state. Interestingly, the spin transition in [1,3-(Me{sub 3}C){sub 2}C{sub 5}H{sub 3}]{sub 2}Mn is accompanied by a phase transition resulting in a significant irreversible hysteresis ({Delta}T{sub c} = 16 K). This structural transition was also observed by extended X-ray absorption fine-structure (EXAFS) measurements. Magnetic susceptibility studies and X-ray diffraction data on SiMe{sub 3} substituted manganocenes [(Me{sub 3}Si){sub n}C{sub 5}H{sub 5-n}]{sub 2}Mn (n= 1, 2, 3) show high-spin configuration in these cases. Although tetra- and hexasubstituted manganocenes are high-spin at all accessible temperatures, the disubstituted manganocenes exhibit a small low-spin admixture at low temperature. In this respect it behaves similarly to [(Me{sub 3}C)(Me{sub 3}Si)C{sub 5}H{sub 3}]{sub 2}Mn, which has a constant low-spin admixture up to 90 K and then gradually converts to high-spin. Thermal spin-trapping can be observed for [(Me{sub 3}C)(Me{sub 3}Si)C{sub 5}H{sub 3}]{sub 2}Mn on rapid cooling.

Pluth, Michael D.; Bergman, Robert G.; Raymond, Kenneth N.

2008-04-17T23:59:59.000Z

412

Catalytic conversion of light alkanes - phase V. Topical report, February 1993--October 1994  

SciTech Connect (OSTI)

We have made excellent progress toward a practical route from field butanes to MTBE, the oxygenate of choice for high-octane, clean-burning, environmentally acceptable reformulated gasoline. We have evaluated two proprietary process possibilities with a potential commercial partner and have conducted a joint catalyst evaluation program. The first of the two potential processes considered during the past quarter utilizes a two-step route from isobutane to tert-butyl alcohol, TBA. Not only is TBA an intermediate for MTBE production but is equally applicable for ETBE-an oxygenate which utilizes renewable ethanol in its` manufacture. In the two-step process, isobutane is oxidized in a non-catalytic reaction to a roughly equal mixture of TBA and tert-butyl hydroperoxide. TBHP, eq. 1. We have developed an inexpensive new catalyst system based on an electron-deficient macrocyclic metal complex that selectively converts TBHP to TBA, eq. 2, and meets or exceeds all of the process criteria that we have set.

NONE

1998-12-31T23:59:59.000Z

413

Graphene composite for improvement in the conversion efficiency of flexible poly 3-hexyl-thiophene:[6,6]-phenyl C{sub 71} butyric acid methyl ester polymer solar cells  

SciTech Connect (OSTI)

The solution of thin graphene-sheets obtained from a simple ultrasonic exfoliation process was found to chemically interact with [6,6]-phenyl C{sub 71} butyric acid methyl ester (PCBM) molecules. The thinner graphene-sheets have significantly altered the positions of highest occupied molecular orbital and lowest unoccupied molecular orbital of PCBM, which is beneficial for the enhancement of the open circuit voltage of the solar cells. Flexible bulk heterojunction solar cells fabricated using poly 3-hexylthiophene (P3HT):PCBM-graphene exhibited a power conversion efficiency of 2.51%, which is a ?2-fold increase as compared to those fabricated using P3HT:PCBM. Inclusion of graphene-sheets not only improved the open-circuit voltage but also enhanced the short-circuit current density owing to an improved electron transport.

Chauhan, A. K., E-mail: akchau@barc.gov.in, E-mail: akc.barc@gmail.com; Gusain, Abhay; Jha, P.; Koiry, S. P.; Saxena, Vibha; Veerender, P.; Aswal, D. K.; Gupta, S. K. [Technical Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India)

2014-03-31T23:59:59.000Z

414

4-Vinyl-, 4-vinyl-, and 4'-vinyl-2,2':6',2''-terpyridinyl ligands: their synthesis and the electrochemistry of their transition-metal coordination complexes  

SciTech Connect (OSTI)

4'-Vinyl-2,2':6',2''-terpyridinyl was conveniently prepared from 2-acetylpyridine via -oxoketene dithioacetal methodology, the intermediate 4'-(methylthio)-2,2':6',2''-terpyridinyl being converted into the corresponding 4'-methyl derivative with methylmagnesium bromide and bis(triphenylphosphino)nickel(II) dichloride followed by generation of the methyl anion with lithium tetramethylpiperidide, reaction of the anion with chloromethyl methyl ether, and introduction of the vinyl group by treatment of the ether with potassium tert-butoxide/THF. Analogous reactions led to the 4-vinyl- and 6-vinyl isomers by using the appropriate methyl-substituted 2-acetylpyridine except that in these instances desulfurization of the 4'-methylthio group with nickel boride was an addition step. These vinyl-substituted ligands formed a variety of readily electropolymerizable simple and mixed-ligand complex monomers with cobalt, ruthenium, and iron with polymerization rates whose magnitude varied with position and number of vinyl substituents.

Potts, K.T.; Usifer, D.A.; Guadalupe, A.; Abruna, H.D.

1987-06-24T23:59:59.000Z

415

THERMODYNAMICS OF EXTRACTION OF NITRIC ACID BY TRI-n-BUTYL PHOSPHATE--HYDROCARBON DILUENT SOLUTIONS  

E-Print Network [OSTI]

the mean act ivi ty coefficient T of TBP and TBP.H20 i n the acid-free, water-saturated organic phase

Wallace Davis

1961-01-01T23:59:59.000Z

416

Safe conditions for contacting nitric acid or nitrates with tri-n-butyl phosphate (TBP)  

SciTech Connect (OSTI)

In response to a request from DOE-SR, the current state of knowledge of the reactions between TBP and aqueous nitrate solutions is critically reviewed, and recommendations are made for the safe operation of SRS separations equipment in which this combination of chemicals may be present. The existing limits for evaporation are validated. Guidelines are presented for cases in which general limits do not apply. The rate of reaction between nitric acid and TBP appears to be controlled by the rate of TBP hydrolysis. The hydrolysis reaction produces dibutyl phosphate and n-butanol. The hydrolysis rate is a strong function of temperature, and becomes very fast at temperatures in the range 130{degrees} to 150{degrees}C. The resulting n-butanol is volatile at high temperatures, boiling at 117.5{degrees}C, but is also subject to exothermic oxidation by nitric acid or nitrates. If oxidation occurs before the n-butanol evaporates, the heat of oxidation may exceed local cooling by convection. The resulting heating will further accelerate the reaction, leading to an energetic runaway and possibly (in confined systems) an explosion. Extensive experiments and practice have shown that in a well-mixed and well-vented aqueous system such as an evaporator, at moderate acidities and temperatures below 130{degrees}C, the heat of reaction is adequately removed by vaporization of steam. In general, the heating will be so slow that natural processes provide adequate cooling at temperatures below 80{degrees}C. Above this temperature, care should be taken to ensure that adequate cooling is available for the amount of TBP that may be present. Experiments suggest that in well-ventilated systems n-butanol evaporation and convective cooling are sufficient to control the reaction at temperatures up to 120{degrees}C.

Hyder, M.L

1994-01-01T23:59:59.000Z

417

Optical fibers by butyl methacrylate reactive extrusion Berthet Romuald, Chalamet Yvan, Taha Mohamed*, Zerroukhi Amar  

E-Print Network [OSTI]

limitations. Reactive extrusion experiments were carried out in a twin-screw extruder and the effect optical fibbers, polymethacrylate. Introduction Twin screw extruders are playing an increasing role of reactive extrusion is explained by the different advantages offered by the use of the twin-screw extruders

Paris-Sud XI, Université de

418

E-Print Network 3.0 - aluminum triso-ethylphosphonate butylate...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Resistance Advancements: Dr. Dragan CurcijaDr. Dragan Curcija Summary: -Expanded (EPS) Pine or Douglas Fir Frame Cavity Polyfoam tape Urethane Sealant Silicone...

419

The K-band microwave spectra of t-butyl halides  

E-Print Network [OSTI]

result of centrifugal distortion of the mole? cule, and (c) a group of lines from either the hindered internal rotation of the CH^ groups or torsional vibration along the C-CH-j bonds, or both. In an attempt to determine the sources of the indi... absorption lines in the microwave re? gion were reported by Cleeton and Williams (2) in 1934* No more papers on this subject appeared in the literature until 1946. Since this latter date, however, some 400 papers relating to miorowave absorption spectra...

Crook, George Hardy

1954-01-01T23:59:59.000Z

420

E-Print Network 3.0 - acaricide tri-n-butyl tin Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of California, Davis; Seybold, Steven J. - Departments of Entomology and Forest Resources, University of Minnesota Collection: Biotechnology ; Environmental Sciences and...

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Saponification rates of isomeric butyl esters in aqueous 1,4-dioxane  

E-Print Network [OSTI]

. Jensen, G. M. Watson and J. B. Beckham, Anal. Chem., 23, 1711-8(1951). (21). F. Daniels, J. H. Mathews and J, W. Williams, "Experimental Physical Chemistry," 3rd. ed., McGraw-Hill Book Co., Inc., New York, N. Y., 19*4-1, p. 167. (22). S. Glasstone...

Ruhnke, Edward Vincent

1954-01-01T23:59:59.000Z

422

E-Print Network 3.0 - antagonist o-4-ethoxyl-butyl-berbamine...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Kim, Elliot Hawkes, Kyujin Cho, Matthew Jolda, Joe Foley and Robert Wood Summary: of micro-coil spring, we present a novel mesh-worm prototype that utilizes bio-inspired...

423

acid t-butyl ester: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

stable thermodynamically and hydration free energies obtained Yu, Fangqun 189 ANTIBODY PURIFICATION USING CAPRYLIC ACID In mildly acidic conditions, the addition of short-chain...

424

E-Print Network 3.0 - acetone-butyl alcohol fermentation Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

then extended this approach to alcoholic fermentation and demonstrated clearly that the process required... the presence of yeast. Alcoholic fermentation was ... Source: Centre...

425

Photochemistry of 1 and 2-(2-methylphenyl)-1,6-heptadiene. [4a-methyl-1,2,3,4,4a,9,10,10a-octahydrophenanthrene  

SciTech Connect (OSTI)

In an attempt to synthesize partially saturated phenanthrene derivatives by an intramolecular Diels-Alder reaction between a photochemically produced o-xylylene (diene) and a tethered dienophile, it was found that 1 and 2 underwent a photochemically allowed (2 + 2) cycloaddition. Irradiation of 1 gave 6-(2-methylphenyl)bicyclo(3.2.0)heptane in 86% yield. Upon irradiation of 2, a benzvalene rearrangement of 2 first took place, producing the meta isomer 2-(3-methylphenyl)-1,6-heptadiene, followed by a (2 + 2) photocycloaddition giving 1-(3-methylphenyl)bicyclo(3.2.0)heptane in 15% yield. Direct irradiation of 2-(3-methylphenyl)-1,6-heptadiene gave the same bicyclo derivative as 2 in 34% yield. Examination of the fluorescence spectra of 1 and 2 in comparison with 1-(2-methylphenyl)propene and 2-(2-methylphenyl)-1-butene, respectively, has shown that 1 may be biased toward (2 + 2) cycloaddition where 2 is not biased toward (2 + 2) photocycloization. Attempts to produce 4a-methyl-1,2,3,4,4a,9,10,10a-octahydrophenanthrene by an intramolecular Diels-Alder reaction of the o-xylylene produced by irradiation of 3 will also be described.

Barrows, R.D.; Hornback, J.M.

1982-01-01T23:59:59.000Z

426

2-(3-Methoxyphenyl)-5-methyl-1,8-naphthyridin-4(1H)-one (HKL-1) induces G2/M arrest and mitotic catastrophe in human leukemia HL-60 cells  

SciTech Connect (OSTI)

2-(3-Methoxyphenyl)-5-methyl-1,8-naphthyridin-4(1H)-one (HKL-1), a 2-phenyl-1,8-naphthyridin-4-one (2-PN) derivative, was synthesized and evaluated as an effective antimitotic agent in our laboratory. However, the molecular mechanisms are uncertain. In this study, HKL-1 was demonstrated to induce multipolar spindles, sustain mitotic arrest and generate multinucleated cells, all of which indicate mitotic catastrophe, in human leukemia HL-60 cells. Western blotting showed that HKL-1 induces mitotic catastrophe in HL-60 cells through regulating mitotic phase-specific kinases (down-regulating CDK1, cyclin B1, CENP-E, and aurora B) and regulating the expression of Bcl-2 family proteins (down-regulating Bcl-2 and up-regulating Bax and Bak), followed by caspase-9/-3 cleavage. These findings suggest that HKL-1 appears to exert its cytotoxicity toward HL-60 cells in culture by inducing mitotic catastrophe. Highlights: ? HKL-1 is a potential antimitotic agent against HL-60 cells. ? HKL-1 induces spindle disruption and sustained resulted in mitotic catastrophe. ? CENP-E and aurora B protein expressions significantly reduced. ? Bcl-2 family protein expressions altered and caspase-9/-3 activation. ? HKL-1 is an attractive candidate for possible use as a novel antimitotic agent.

Hsu, Mei-Hua; Liu, Chin-Yu; Lin, Chiao-Min; Chen, Yen-Jung; Chen, Chun-Jen; Lin, Yu-Fu; Huang, Li-Jiau [Graduate Institute of Pharmaceutical Chemistry, China Medical University, Taichung, Taiwan, ROC (China)] [Graduate Institute of Pharmaceutical Chemistry, China Medical University, Taichung, Taiwan, ROC (China); Lee, Kuo-Hsiung [Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States) [Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Chinese Medicine Research and Development Center, China Medical University and Hospital, Taichung, Taiwan, ROC (China); Kuo, Sheng-Chu, E-mail: sckuo@mail.cmu.edu.tw [Graduate Institute of Pharmaceutical Chemistry, China Medical University, Taichung, Taiwan, ROC (China)] [Graduate Institute of Pharmaceutical Chemistry, China Medical University, Taichung, Taiwan, ROC (China)

2012-03-01T23:59:59.000Z

427

Reactive formulations for a neutralization of toxic industrial chemicals  

DOE Patents [OSTI]

Decontamination formulations for neutralization of toxic industrial chemicals, and methods of making and using same. The formulations are effective for neutralizing malathion, hydrogen cyanide, sodium cyanide, butyl isocyanate, carbon disulfide, phosgene gas, capsaicin in commercial pepper spray, chlorine gas, anhydrous ammonia gas; and may be effective at neutralizing hydrogen sulfide, sulfur dioxide, formaldehyde, ethylene oxide, methyl bromide, boron trichloride, fluorine, tetraethyl pyrophosphate, phosphorous trichloride, arsine, and tungsten hexafluoride.

Tucker, Mark D. (Albuqueruqe, NM); Betty, Rita G. (Rio Rancho, NM)

2006-10-24T23:59:59.000Z

428

Two US markets, or one? How the MTBE-gasoline relationship is evolving  

SciTech Connect (OSTI)

This issue of Energy Detente features the price sensitivity of Methyl Tertiary Butyl Ether. Data is presented for US wholesale gasoline prices vs. MTBE for the 20-month period beginning in June 1994 and ending in January 1996, and the data is discussed. Also contained in this issue is the refining netback data and the fuel price/tax data for the period ending January 5, 1996.

NONE

1996-01-26T23:59:59.000Z

429

Statoil outlines MTBE development program  

SciTech Connect (OSTI)

This paper reports that Norway's state oil company Den Norkse state Oljeselskap AS has outlined plans to become one of the major European producers of methyl tertiary butyl ether in the 1990s. Statoil predicts European demand for MTBE will jump to 4.5 million metric tons/year by 2000 from 2.5 million tons in 1990. Europe currently is a net importer of MTBE, with a productive capacity of 2.2 million tons/year.

Not Available

1991-11-25T23:59:59.000Z

430

New etherification process commercialized in Finland  

SciTech Connect (OSTI)

The phase-out of leaded fuels in Europe, Asia, and parts of Africa and Latin America is increasing demand for octane and octane-bearing fuel components such as ethers. Early solutions to the problem of increasing octane while reducing tailpipe emissions involved use of methyl tertiary butyl ether (MTBE). According to Neste, using both tertiary amyl methyl ether (TAME) and MTBE can give refiners increased blending flexibility for volatility control. But the economics associated with TAME production often make TAME units difficult to justify. The paper discusses the NExTAME process, the unit at the Porvoo refinery and process improvements.

NONE

1997-01-06T23:59:59.000Z

431

A novel approach for the characterization of a bilayer of phenyl-c71-butyric-acid-methyl ester and pentacene using ultraviolet photoemission spectroscopy and argon gas cluster ion beam sputtering process  

SciTech Connect (OSTI)

The material arrangement and energy level alignment of an organic bilayer comprising of phenyl-c71-butyric-acid-methyl ester (PCBM-71) and pentacene were studied using ultraviolet photoelectron spectroscopy (UPS) and the argon gas cluster ion beam (GCIB) sputtering process. Although there is a small difference in the full width at half maximum of the carbon C 1s core level peaks and differences in the oxygen O 1s core levels of an X-ray photoemission spectroscopy spectra, these differences are insufficient to clearly distinguish between PCBM-71 and pentacene layers and to classify the interface and bulk regions. On the other hand, the valence band structures in the UPS spectra contain completely distinct configurations for the PCBM-71 and pentacene layers, even when they have similar atomic compositions. According to the valence band structures of the PCBM-71/pentacene/electrodes, the highest unoccupied molecular orbital (HOMO) region of pentacene is at least 0.8 eV closer to the Fermi level than that of PCBM-71 and it does not overlap with any of the chemical states in the valence band structure of PCBM-71. Therefore, by just following the variations in the area of the HOMO region of pentacene, the interface/bulk regions of the PCBM/pentacene layers were distinctly categorized. Besides, the variation of valence band structures as a function of the Ar GCIB sputtering time fully corroborated with the surface morphologies observed in the atomic force microscope images. In summary, we believe that the novel approach, which involves UPS analysis in conjunction with Ar GCIB sputtering, can be one of the best methods to characterize the material distribution and energy level alignments of stacks of organic layers.

Yun, Dong-Jin; Chung, JaeGwan; Jung, Changhoon; Chung, Yeonji; Kim, SeongHeon; Lee, Seunghyup; Kim, Ki-Hong; Han, Hyouksoo; Park, Gyeong-Su; Park, SungHoon [Analytical Science Laboratory of Samsung Advanced Institute of Technology, P.O. Box 14-1, Yongin 446-712 (Korea, Republic of)] [Analytical Science Laboratory of Samsung Advanced Institute of Technology, P.O. Box 14-1, Yongin 446-712 (Korea, Republic of)

2013-09-07T23:59:59.000Z

432

Coal-transformation chemistry. Fourth quarterly progress report  

SciTech Connect (OSTI)

Pyrene, perylene, anthracene, 9,10-diphenylanthracene, naphthalene and biphenyl have been employed as electron transfer agents in the reduction of Illinois No. 6 coal with potassium in tetrahydrofuran. These electron transfer agents are about equally effective for the reduction of this coal at short reaction times (3 hours). We conclude that the anions of biphenyl and naphthalene achieve a greater degree of electron transfer to the coal molecules and that the use of these anions enhances the fragmentation reactions of the coal. Illinois No. 6 bituminous coal and Colorado subbituminous coal were reacted with potassium dissolved in a mixture of monoglyme and triglyme at -50/sup 0/C. The reduction reaction proceeded via solvated electrons rather than by an electron transfer reaction. The coals were then alkylated with methyl iodide and their solubilities in tetrahydrofuran were determined. The Illinois coal reductively alkylated via solvated electrons was considerably less soluble in tetrahydrofuran than the same coal reductively alkylated with potassium and naphthalene in tetrahydrofuran. A sample of Illinois No. 6 coal which had been reductively butylated with n-butyl-1-/sup 13/C iodide was hydrolyzed. Carbon nmr spectroscopy of the hydrolyzed coal revealed that the resonances previously assigned either to the presence of n-butyl carboxylates or to n-butyl tertiary ethers were removed. This observation provides definite evidence that only carboxylates were present in the original alkylated product. Selective alkylation of the acidic hydroxyl groups in Illinois No. 6 coal was carried out using tetrabutylammonium hydroxide as a phase transfer catalyst and iodomethane or 1-iodobutane as alkylating agent as described by Liotta. The tetrahydrofuran solubility of the product was significantly improved in a reaction where reductively butylated coal was subsequently coal was subsequently methylated using Liotta's procedure.

Stock, Leon M.; Blain, D. A.; Handy, C. I.; Heimann, P.; Huang, C. B.; King, H. -H.; Landschulz, W.; Willis, R. S.

1980-01-01T23:59:59.000Z

433

High pressure chemistry of substituted acetylenes  

SciTech Connect (OSTI)

High pressure in situ synchrotron x-ray diffraction experiments were performed on substituted polyacetylenes: tert-butyl acetylene [TBA: (CH{sub 3}){sub 3}-C{triple_bond}CH] and ethynyl trimethylsilane [ETMS: (CH{sub 3}){sub 3}-Si{triple_bond}CH] to investigate pressure-induced chemical reactions. The starting samples were the low temperature crystalline phases which persisted metastably at room temperature and polymerized beyond 11 GPa and 26 GPa for TBA and ETMS respectively. These reaction onset pressures are considerably higher than what we observed in the shockwave studies (6.1 GPa for TBA and 6.6 GPa for ETMS). Interestingly, in the case of ETMS, it was observed with fluid ETMS as starting sample, reacts to form a semi-crystalline polymer (crystalline domains corresponding to the low-T phase) at pressures less than {approx}2 GPa. Further characterization using vibrational spectroscopy is in progress.

Chellappa, Raja [Los Alamos National Laboratory; Dattelbaum, Dana [Los Alamos National Laboratory; Sheffield, Stephen [Los Alamos National Laboratory; Robbins, David [Los Alamos National Laboratory

2011-01-25T23:59:59.000Z

434

5, 13611378, 2008 Methyl arsenic and  

E-Print Network [OSTI]

to assure the drinking and industrial water supply to one of the most populated areas to be directly correlated to the winter spate. As the biological activity in the water body is generally low the translocation of soil- and sediment particles to the river by heavy rains and the melting of snow. A second

Paris-Sud XI, Université de

435

Molecular Cell Methylation of a Histone Mimic  

E-Print Network [OSTI]

,3 Andrew N. Krutchinsky,2 Ingrid Mecklenbra¨ uker,1 Agnes Viale,5 Eugene Rudensky,1 Ming-Ming Zhou,4., 2004; Huang et al., 2006; Kouskouti et al., 2004; Zhang et al., 2005). In contrast, little progr

Chait, Brian T.

436

METHYL CYANIDE OBSERVATIONS TOWARD MASSIVE PROTOSTARS  

SciTech Connect (OSTI)

We report the results of a survey in the CH{sub 3}CN J = 12 {yields} 11 transition toward a sample of massive proto-stellar candidates. The observations were carried out with the 10 m Submillimeter Telescope on Mount Graham, AZ. We detected this molecular line in 9 out of 21 observed sources. In six cases this is the first detection of this transition. We also obtained full beam sampled cross-scans for five sources which show that the lower K-components can be extended on the arcminute angular scale. The higher K-components, however, are always found to be compact with respect to our 36'' beam. A Boltzmann population diagram analysis of the central spectra indicates CH{sub 3}CN column densities of about 10{sup 14} cm{sup -2}, and rotational temperatures above 50 K, which confirms these sources as hot molecular cores. Independent fits to line velocity and width for the individual K-components resulted in the detection of an increasing blueshift with increasing line excitation for four sources. Comparison with mid-infrared (mid-IR) images from the SPITZER GLIMPSE/IRAC archive for six sources show that the CH{sub 3}CN emission is generally coincident with a bright mid-IR source. Our data clearly show that the CH{sub 3}CN J = 12 {yields} 11 transition is a good probe of the hot molecular gas near massive protostars, and provide the basis for future interferometric studies.

Rosero, V.; Hofner, P. [Physics Department, New Mexico Tech, 801 Leroy Place, Socorro, NM 87801 (United States); Kurtz, S. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Morelia 58090 (Mexico); Bieging, J. [Department of Astronomy and Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Araya, E. D. [Physics Department, Western Illinois University, 1 University Circle, Macomb, IL 61455 (United States)

2013-07-01T23:59:59.000Z

437

Phytoremediation of Ionic and Methyl Mercury P  

SciTech Connect (OSTI)

Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic heavy metal pollutants as an environmentally friendly alternative to physical remediation methods. We have focused this phytoremediation research on soil and water-borne ionic and methylmercury. Mercury pollution is a serious world-wide problem affecting the health of human and wild-life populations. Methylmercury, produced by native bacteria at mercury-contaminated wetland sites, is a particularly serious problem due to its extreme toxicity and efficient biomagnification in the food chain. We engineered several plant species (e.g., Arabidopsis, tobacco, canola, yellow poplar, rice) to express the bacterial genes, merB and/or merA, under the control of plant regulatory sequences. These transgenic plants acquired remarkable properties for mercury remediation. (1) Transgenic plants expressing merB (organomercury lyase) extract methylmercury from their growth substrate and degrade it to less toxic ionic mercury. They grow on concentrations of methylmercury that kill normal plants and accumulate low levels of ionic mercury. (2) Transgenic plants expressing merA (mercuric ion reductase) extract and electrochemically reduce toxic, reactive ionic mercury to much less toxic and volatile metallic mercury. This metal transformation is driven by the powerful photosynthetic reducing capacity of higher plants that generates excess NADPH using solar energy. MerA plants grow vigorously on levels of ionic mercury that kill control plants. Plants expressing both merB and merA degrade high levels of methylmercury and volatilize metallic mercury. These properties were shown to be genetically stable for several generations in the two plant species examined. Our work demonstrates that native trees, shrubs, and grasses can be engineered to remediate the most abundant toxic mercury pollutants. Building on these data our working hypothesis for the next grant period is that transgenic plants expressing the bacterial merB and merA genes will (a) remove mercury from polluted soil and water and (b) prevent methylmercury from entering the food chain. Our specific aims center on understanding the mechanisms by which plants process the various forms of mercury and volatilize or transpire mercury vapor. This information will allow us to improve the design of our current phytoremediation strategies. As an alternative to volatilizing mercury, we are using several new genes to construct plants that will hyperaccumulate mercury in above-ground tissues for later harvest. The Department of Energy's Oak Ridge National Laboratory and Brookhaven National Laboratory have sites with significant levels of mercury contamination that could be cleaned by applying the scientific discoveries and new phytoremediation technologies described in this proposal. The knowledge and expertise gained by engineering plants to hyperaccumulate mercury can be applied to the remediation of other heavy metals pollutants (e.g., arsenic, cesium, cadmium, chromium, lead, strontium, technetium, uranium) found at several DOE facilities.

Meagher, Richard B.

1999-06-01T23:59:59.000Z

438

Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. Quarterly technical progress report No. 3, April 1, 1991--June 30, 1991  

SciTech Connect (OSTI)

The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butytl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch; (2) addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst; and, (3) addition of methanol to slurry phase FT synthesis making iso-olefins.

Marcelin, G.

1991-10-15T23:59:59.000Z

439

Oxygenates du`jour...MTBE? Ethanol? ETBE?  

SciTech Connect (OSTI)

There are many different liquids that contain oxygen which could be blended into gasoline. The ones that have been tried and make the most sense are in the alcohol (R-OH) and ether (R-O-R) chemical family. The alcohols considered are: methanol (MeOH), ethanol (EtOH), tertiary butyl alcohol (TBA). The ethers are: methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), tertiary amyl ethyl ether (TAEE), di-isopropyl ether (DIPE). Of the eight oxygenates listed above, the author describes the five that are still waiting for widespread marketing acceptance (methanol, TBA, TAME, TAEE, and DIPE). He then discusses the two most widely used oxygenates in the US, MTBE and ethanol, along with the up-and-coming ethanol ether, ETBE. Selected physical properties for all of these oxygenates can be found in Table 2 at the end of this paper. A figure shows a simplified alcohol/ether production flow chart for the oxygenates listed above and how they are interrelated.

Wolfe, R.

1995-12-31T23:59:59.000Z

440

Chemical factors affecting insolubles formation in shale derived diesel fuel  

SciTech Connect (OSTI)

Detrimental changes in fuel properties with time have been a continuing problem in the use of middle distillate fuels. Instability of diesel fuels is usually defined by the formation of insoluble sediments and gums. Gravimetric stability tests have been conducted at 43/sup 0/ and 80/sup 0/C, respectively, using three model nitrogen heterocycles, 2-methylpyridine, 2,6-di methyl quinoline, and dodecahydrocarbazole, as dopants in an otherwise stable shale diesel fuel. Potential interactive effects have been defined for these three model nitrogen heterocycles in the stable fuel in the presence of a second model dopant, t-butyl hydroperoxide. 2-Methyl pyridine and 2,6-dimethyl quinoline were inactive and only 2-methyl pyridine showed slight positive interactive effects. Dodecahydrocarbazole formed large amounts of insolubles by itself and exhibited positive interactive effects.

Beal, E.J.; Mushrush, G.W.; Cooney, J.V. (Fuels Section, Code 6180 Naval Research Lab., Washington, DC (US)); Watkins, J.M. (Geo-Centers, Ft. Washington, MD (US))

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Texas plant will use new process to coproduce propylene oxide, MTBE  

SciTech Connect (OSTI)

Texaco Chemical Co. is building a $400 + million facility to produce 1.2 billion lb/year (14,000 b/d) methyl tertiary butyl ether (MTBE) and 400 million lb/year (about 500 metric tons/day) propylene oxide (PO). The facility-under construction at Port Neches, Tex.-will utilize a newly developed Texaco process that coproduces the two chemicals. The process produces propylene oxide and tertiary butyl alcohol (TBA) from the reaction of isobutane with oxygen in one step, then in a second step with propylene. The TBA is then reacted with methanol in a one-step process that synthesizes MTBE. The paper describes the Port Neches facilities, construction schedule, feedstocks, product uses, and auxiliary equipment.

Rhodes, A.K.

1993-08-30T23:59:59.000Z

442

On the structural and impedance characteristics of Li- doped PEO, using n-butyl lithium in hexane as dopant  

SciTech Connect (OSTI)

Nowadays polymer based solid state electrolytes for applications in rechargeable battery systems are highly sought after materials, pursued extensively by various research groups worldwide. Numerous methods are discussed in literature to improve the fundamental properties like electrical conductivity, mechanical stability and interfacial stability of polymer based electrolytes. The application of these electrolytes in Li-ion cells is still in the amateur state, due to low ionic conductivity, low lithium transport number and the processing difficulties. The present work is an attempt to study the effects of Li doping on the structural and transport properties of the polymer electrolyte, poly-ethelene oxide (PEO) (Molecular weight: 200,000). Li doped PEO was obtained by treating PEO with n-Butyllithium in hexane for different doping concentrations. Structural characterization of the samples was done by XRD and FTIR techniques. Impedance measurements were carried out to estimate the ionic conductivity of Li doped PEO samples. It is seen that, the crystallinity of the doped PEO decreases on increasing the doping concentration. XRD and FTIR studies support this observation. It is inferred that, ionic conductivity of the sample is increasing on increasing the doping concentration since less crystallinity permits more ionic transport. Impedance measurements confirm the results quantitatively.

Anand, P. B., E-mail: anandputhirath@gmail.com, E-mail: jayalekshmi@cusat.ac.in; Jayalekshmi, S., E-mail: anandputhirath@gmail.com, E-mail: jayalekshmi@cusat.ac.in [Division for Research in Advanced Materials Department of Physics Cochin University of Science and Technology Cochin 22, Kerala (India)

2014-01-28T23:59:59.000Z

443

Safety of Tri-n-butyl phosphate (TBP) and nitric acid solutions in two-phase systems at elevated temperatures  

SciTech Connect (OSTI)

This paper addresses the prevention of self-accelerating oxidation of nitric acid and tributyl phosphate (TBP). An accident of this type, which occurred at Tomsk-7, Russia, in 1993, resulted from a slow chemical reaction occurring initially at sub-boiling temperatures. The accumulating heat and vapors overpressurized and burst a process tank. Two safety issues are addressed in this summary of experimental data: circumstances under which convection or radiation cooling of vessels will exceed reaction heat, and measures which can prevent or mitigate such reactions. Heat generations rates have been found to range widely. Thermodynamic calculations confirm that heat generation is reduced by a large factor when nitrogen oxides are able to escape from the reaction mixure. Scoping calculations show that the evaporation of water is potentially the most effective mechanism for heat removal in a large vessel, and experiments have demonstrated that water evaporation is effective for preventing runaway reactions in a vented, two-phase system operated below about 120 C. These data indicate that venting is the key to controlling runaway reactions. However, other experiments have indicated that the self-heating reaction did not present a danger, even if reaction heating led to an accelerating reaction, in a sufficiently vented system. To determine how much venting was required, experiments were performed with pure organic phase and two-phase TBP-nitric acid mixtures. Data show a critical ratio of organic mass to vent area, above which the reacting system can reach potentially dangerous pressures. Experiments show runaway reactions occurring in vented systems only as the temperature approaches 130 C. These results clearly indicate that adequate venting of vessels containing heated TBP and nitrate is the key to controlling their reaction.

Hyder, M.L.; Paddleford, D.F.; Thompson, M.C. [Westinghouse Savannah River Company, Aiken, SC (United States)

1995-12-31T23:59:59.000Z

444

An experimental system for the n-butyl-lithium initiated polymerization of styrene in a multi-sampled batch reactor  

E-Print Network [OSTI]

. The power to the water heater is controlled by a Fisher Proportional Temperature Control (Catalog P3 TENPERATURE CONTROLLER CONSTANT TENPERATURE BATH P2 CHILLER ELECTRICAL HEATER Figure 3. Schematic of Reactor Temperature Control System 20... successful column; i, e, , extremely high pressure drops and low plate counts were observed in these columns. As a last measure, the gel was stirred in a hot, concen- trated sodium hydroxide solution (approximately pH 13) for ten hours. The excess sodium...

Cox, James Harvey

2012-06-07T23:59:59.000Z

445

The Role of the Ocean in the Atmospheric Budgets of Methyl Bromide, Methyl Chloride and Methane  

E-Print Network [OSTI]

, which was 700 (490 to 920) Gg yr^-1 and -370 (-440 to -280) Gg yr^-1, respectively. The ocean accounts for 10 - 19 % in the global CH3Cl emission and 6 - 9 % in its global sinks. Methane (CH4) is a potent greenhouse gas, which has a warming potential...

Hu, Lei

2012-10-19T23:59:59.000Z

446

Telomere lengthening to antagonize myocardial aging  

E-Print Network [OSTI]

with Topro (blue). B. PLA for Pim-1 and TERT interactionswt NRCMs demonstrated by PLA (red dots). Figure 2.4: TERT/taken 7 days after MI. C. PLA analysis of Pim-1 and TERT,

Cottage, Christopher Travis; Cottage, Christopher Travis

2012-01-01T23:59:59.000Z

447

Testing of a model to estimate vapor concentration of various organic chemicals. Master's thesis  

SciTech Connect (OSTI)

A model developed by Dr. Parker C. Reist to predict the build-up and decay rates of vapor concentrations following a chemical spill and clean-up was tested. The chemicals tested were: acetone, butyl acetate, ethyl acetate, hexane, methylene chloride, methyl ethyl ketone, and toluene. The evaporation rates of these chemicals were determined both by prediction, using a model developed by I. Kawamura and D. Mackay, and empirically and these rates were used in the Reist model. Chamber experiments were done to measure actual building-up and decay of vapor concentrations for simulated spills and simulated clean-up.

Bakalyar, S.M.

1990-01-01T23:59:59.000Z

448

California's Move Toward E10 (released in AEO2009)  

Reports and Publications (EIA)

In Annual Energy Outlook 2009, (AEO) E10–a gasoline blend containing 10% ethanol–is assumed to be the maximum ethanol blend allowed in California erformulated gasoline (RFG), as opposed to the 5.7% blend assumed in earlier AEOs. The 5.7% blend had reflected decisions made when California decided to phase out use of the additive methyl tertiary butyl ether in its RFG program in 2003, opting instead to use ethanol in the minimum amount that would meet the requirement for 2.0% oxygen content under the Clean Air Act provisions in effect at that time.

2009-01-01T23:59:59.000Z

449

Oxygenate Supply/Demand Balances in the Short-Term Integrated Forecasting Model (Released in the STEO March 1998)  

Reports and Publications (EIA)

The blending of oxygenates, such as fuel ethanol and methyl tertiary butyl ether (MTBE), into motor gasoline has increased dramatically in the last few years because of the oxygenated and reformulated gasoline programs. Because of the significant role oxygenates now have in petroleum product markets, the Short-Term Integrated Forecasting System (STIFS) was revised to include supply and demand balances for fuel ethanol and MTBE. The STIFS model is used for producing forecasts in the Short-Term Energy Outlook. A review of the historical data sources and forecasting methodology for oxygenate production, imports, inventories, and demand is presented in this report.

1998-01-01T23:59:59.000Z

450

MTBE, Oxygenates, and Motor Gasoline (Released in the STEO October 1999)  

Reports and Publications (EIA)

The blending of methyl tertiary butyl ether (MTBE) into motor gasoline has increased dramatically since it was first produced 20 years ago. MTBE usage grew in the early 1980's in response to octane demand resulting initially from the phaseout of lead from gasoline and later from rising demand for premium gasoline. The oxygenated gasoline program stimulated an increase in MTBE production between 1990 and 1994. MTBE demand increased from 83,000 in 1990 to 161,000 barrels per day in 1994. The reformulated gasoline (RFG) program provided a further boost to oxygenate blending. The MTBE contained in motor gasoline increased to 269,000 barrels per day by 1997.

1999-01-01T23:59:59.000Z

451

Evaluation and Optimization of MTBE Biodegradation in Aquifers, Final Report  

SciTech Connect (OSTI)

This study was focused on meeting the following objectives concerning the process of methyl tertiary butyl ether (MTBE) biodegradation, with the goal of optimizing this process in situ: 1. Assess whether intrinsic bioattenuation of MTBE is feasible under aerobic conditions across several contaminated sites. 2. Determine the effect of co-contaminants, specifically water-soluble gasoline components (most notably benzene, toluene, ethylbenzene and xylenes [BTEX]) on MTBE biodegradation. 3. Determine whether microbial and/or chemical factors contribute to different MTBE degradative activities. 4. Isolate and characterize MTBE-degrading microorganisms from sediments in which MTBE biodegradation was observed.

Legler, T; Balser, L; Koester, C; Wilson, W

2004-02-13T23:59:59.000Z

452

Austrian refiner benefits from advanced control  

SciTech Connect (OSTI)

OeMV-AG Energy implemented advanced process controls on 27 units at its refinery in Schwechat, Austria. A variety of controls were implemented on the butadiene and methyl tertiary butyl ether (MTBE) units in January 1993. After more than 1 year of operation, the butadiene/MTBE project has shown a number of benefits, including reduced energy consumption and increased capacity in both units. The paper discusses the process, advanced control, the simple model predictive controller, control objectives, the butadiene unit, the MTBE unit, and benefits of the advanced controllers.

Richard, L.A.; Spencer, M. [Setpoint Inc., Houston, TX (United States); Schuster, R.; Tuppinger, D.M.; Wilmsen, W.F. [OeMV-AG Energy, Schwechat (Austria)

1995-03-20T23:59:59.000Z

453

Petrochem industry expands North American MTBE capacity  

SciTech Connect (OSTI)

This paper reports that petrochemical manufacturers continue to increase methyl tertiary butyl ether (MTBE) capacity in North America. The action reflects refiners' reformulation of gasoline to help reduce auto emissions. Demand for gasoline blending oxygenates such as MTBE is expected to increase as U.S. refiners reconfigure processing trains to produce fuels meeting requirements of the Clean Air Act amendments of 1990. Recent progress includes plans to build an MTBE plant in Mexico and start-ups of plants on the U.S. Gulf Coast and in Canada.

Not Available

1992-10-05T23:59:59.000Z

454

A near infrared regression model for octane measurements in gasolines which contain MTBE  

SciTech Connect (OSTI)

Near infrared (NIR) spectroscopy has emerged as a superior technique for the on-line determination of octane during the blending of gasoline. This results from the numerous advantages that NIR spectroscopy has over conventional on-line instrumentation. Methyl t-butyl ether (MTBE) is currently the oxygenated blending component of choice. MTBE is advantageous because it has a high blending octane, a low Reid vapor pressure, is relatively cheap, and does not form peroxides (1). The goal of this project was to develop a NIR regression model that could be used to predict pump octanes regardless of whether they contained MTBE.

Maggard, S.M. (Ashland Petroleum Co., KY (USA))

1990-01-01T23:59:59.000Z

455

Economics of new MTBE design  

SciTech Connect (OSTI)

Methyl Tertiary Butyl Ether (MTBE) is produced industrially by catalytic reaction between methanol and isobutene. The catalyst that is widely used is an acidic ion exchange resin. This article explores design and economics when sulfuric acid is the catalyst. The profitability of MTBE production depends mainly on the cost of butenes and methhanol. Thus, the example shows MTBE made with a catalyst of sulfuric acid was profitable at a Saudi Arabian location, even though it was not profitable at a U.S. Gulf Coast location.

Al-Jarallah, A.M.; Lee, A.K.K.

1988-07-01T23:59:59.000Z

456

MTBE: Wild card in groundwater cleanup  

SciTech Connect (OSTI)

Subsurface releases of the gasoline oxygenate, methyl tertiary butyl ether (MTBE) seriously compromise the remediation and closure of properties that have ground water contaminated with BTEX and other conventional fuel hydrocarbon components. Although a manageable protocal for BTEX remediation is being set up, the MTBE problem continues to be difficult. This article discusses a new magnesium peroxide compound which could be part of the solution. Covered topics include oxygen release compound (ORC) enhance bioremediation and the role of oxygen and ORC in MTBE remediation. 1 fig.

Koenigsberg, S. [Regenesis Bioremediation Products, San Juan Capistrano, CA (United States)

1997-11-01T23:59:59.000Z

457

Method for measuring surface temperature  

SciTech Connect (OSTI)

The present invention relates to a method for measuring a surface temperature using is a fluorescent temperature sensor or optical thermometer. The sensor includes a solution of 1,3-bis(1-pyrenyl)propane within a 1-butyl-1-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid solvent. The 1,3-bis(1-pyrenyl)propane remains unassociated when in the ground state while in solution. When subjected to UV light, an excited state is produced that exists in equilibrium with an excimer. The position of the equilibrium between the two excited states is temperature dependent.

Baker, Gary A. (Los Alamos, NM); Baker, Sheila N. (Los Alamos, NM); McCleskey, T. Mark (Los Alamos, NM)

2009-07-28T23:59:59.000Z

458

Vanadyl tert-Butoxy Orthosilicate, OV[OSi(OtBu)3]3: A Model for Isolated Vanadyl Sites on Silica and a  

E-Print Network [OSTI]

-containing silica aerogels and xerogels.13-17 In addition, vanadia-silica catalysts have been prepared by treating

Iglesia, Enrique

459

Phase equilibrium measurements on twelve binary mixtures  

SciTech Connect (OSTI)

Phase equilibrium measurements have been performed on twelve binary mixtures. The PTx method was used to obtain vapor-liquid equilibrium data for the following binary systems at two temperatures each: ethanethiol + propylene; nitrobenzene + methanol; pyridine + ethyl acetate; octane + tert-amyl methyl ether; diisopropyl ether + butane; 1,3-dichloro-2-propanol + epichlorohydrin; 2,3-dichloro-1-propanol + epichlorohydrin; 2,3-epoxy-1-propanol + epichlorohydrin; 3-chloro-1,2-propanediol + epichlorohydrin; methanol + hydrogen cyanide. For these systems, equilibrium vapor and liquid phase compositions were derived from the PTx data using the Soave equation of state to represent the vapor phase and the Wilson, NRTL, or Redlich-Kister activity coefficient model to represent the liquid phase. The infinite dilution activity coefficient of methylamine in N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone was determined at three temperatures by performing PTx measurements on the N-methyl-2-pyrrolidone-rich half of the binary. Liquid-liquid equilibrium studies were made on the triethylene glycol + 1-pentene system at two temperatures by directly analyzing samples taken from each liquid phase.

Giles, N.F. [Wiltec Research Co., Inc., Provo, UT (United States)] [Wiltec Research Co., Inc., Provo, UT (United States); Wilson, H.L.; Wilding, W.V. [Brigham Young Univ., Provo, UT (United States). Chemical Engineering Dept.] [Brigham Young Univ., Provo, UT (United States). Chemical Engineering Dept.

1996-11-01T23:59:59.000Z

460

Pool octanes via oxygenates  

SciTech Connect (OSTI)

Increasingly stringent antipollution regulations placed on automobile exhaust gases with consequent reduction or complete lead ban from motor gasoline result in octane shortage at many manufacturing sites. Attractive solutions to this problem, especially in conjunction with abundant methanol supplies, are the hydration and etherification of olefins contained in light product streams from cracking unit or produced by field gas dehydrogenation. A comparison is made between oxygenates octane-volume pool contributions and established refinery technologies. Process reviews for bulk manufacture of fuel-grade isopropanol (IPA), secondary butanol (SBA), tertiary butanol (TBA), methyl tertiary butyl ether (MTBE) and tertiary amyl methyl ether (TAME) are presented together with the characteristic investment and operating data. The implantation of these processes into a typical FCCU refinery complex with the resulting octane-pool improvement possibilities is descried.

Prezelj, M.

1987-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "methyl tert butyl" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Two Pathways for Electrocatalytic Oxidation of Hydrogen by a Nickel Bis(diphosphine) Complex with Pendant Amines in the Second Coordination Sphere  

SciTech Connect (OSTI)

A nickel bis(diphosphine) complex containing pendant amines in the second coordination sphere, [Ni(PCy2Nt-Bu2)2](BF4)2 (PCy2Nt-Bu2 = 1,5-di(tert-butyl)-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane), is an electrocatalyst for hydrogen oxidation. Under 1.0 atm H2 using NEt3 as a base and with added water, a turnover frequency of 45 s-1 is observed at 23 °C; this is the fastest observed for a molecular catalyst. The addition of hydrogen to the NiII complex gives thee isomers of the doubly protonated Ni0 complex [Ni(PCy2HNt-Bu2)2](BF4)2; these complexes have been studied by 1H and 31P NMR spectroscopy, and for one isomer, an X-ray diffraction study. Using the pKa values and NiII/I and NiI/0 redox potentials in a thermochemical cycle, the free energy of hydrogen addition to [Ni(PCy2Nt-Bu2)2]2+ was determined to be -7.9 kcal mol-1. The catalytic rate observed in dry acetonitrile for the oxidation of H2 at the NiII/I couple depends on base size, with larger bases (NEt3, tert-BuNH2) resulting in slower catalysis than n-BuNH2. Addition of water accelerates the rate of catalysis, especially for the larger bases. The results of these studies provide important insights into the design of catalysts for hydrogen oxidation that facilitate proton movement and operate at moderate potentials. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Yang, Jenny Y.; Smith, Stuart E.; Liu, Tianbiao L.; Dougherty, William G.; Hoffert, Wesley A.; Kassel, W. S.; Rakowski DuBois, Mary; DuBois, Daniel L.; Bullock, R. Morris

2013-07-03T23:59:59.000Z

462

Investigation of the Atmospheric Ozone Impacts of Methyl Iodide  

E-Print Network [OSTI]

0692; South Coast Air Quality Management District Contractand South Coast Air Quality Management District, Contractthe South Coast Air Quality Management District Contract No.

Carter, W P L

2007-01-01T23:59:59.000Z

463

acid methyl esters: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 (> 170 o C). Each fraction was analyzed composition of fatty acid ethyl esters using gas chromatography (GC). The result showed that the yield medium chain fatty acid ethyl...

464

acid methyl ester: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 (> 170 o C). Each fraction was analyzed composition of fatty acid ethyl esters using gas chromatography (GC). The result showed that the yield medium chain fatty acid ethyl...

465

Investigation of the Atmospheric Ozone Impacts of Methyl Iodide  

E-Print Network [OSTI]

J. R. Holmes (1977): “Nitrogen Dioxide Photolysis in the LosO3 Ozone NO Nitric Oxide NO2 Nitrogen Dioxide NO3 NitrateNitrogen Pentoxide HONO Nitrous Acid HNO3 Nitric Acid HNO4 Peroxynitric Acid HO2H Hydrogen Peroxide CO Carbon Monoxide SO2 Sulfur Dioxide

Carter, W P L

2007-01-01T23:59:59.000Z

466

Validation in Genomics: CpG Island Methylation Revisited  

E-Print Network [OSTI]

analysis. In: Functional Genomics: Methods and Protocols, M.Segal: Validation in Genomics: CpG Island Methylationpackage and applications to genomics. Bioinformatics and

Segal, Mark R

2006-01-01T23:59:59.000Z

467

Engineering of bacterial methyl ketone synthesis for biofuels  

E-Print Network [OSTI]

ketone synthesis for biofuels Ee-Been Goh†† 1,3 , Edward E.microbes for use as biofuels, such as fatty acid ethylother fatty acid-derived biofuels, such as fatty acid ethyl

Goh, Ee-Been

2012-01-01T23:59:59.000Z

468

The alkaloid of Acacia berlandieri, N-methyl-B-phenylethylamine  

E-Print Network [OSTI]

? HTo -p O ao rH *HPi -p b?| ?H rH CO o lA OJ K\\ O OJ I rH J>> X -p ? t>> rEj rH +> o o w r"i >? ? a c ? >HK a ft d o ?H -P cd CO ^ I?I ?H 3 COo a H cdXi -p A ft o X A? +3 0}o ? s p in t>- r...

Camp, Bennie Joe

1956-01-01T23:59:59.000Z

469

Investigation of the Atmospheric Ozone Impacts of Methyl Iodide  

E-Print Network [OSTI]

Glyphosate, isopropylamine salt Acrolein Glycerine Propylenefrom methacrolein and other acroleins. Steady State Radical

Carter, W P L

2007-01-01T23:59:59.000Z

470

DOEEA-1157 ENVIRONlMENTAL ASSESSMENT METHYL CHLORIDE VIA OXYHYDROCHLOF...  

Broader source: Energy.gov (indexed) [DOE]

VIA OXYHYDROCHLOFUNATION OF METHANE: A BUILDING BLOCK FOR CHEMICALS AND FUELS FROM NATURAL GAS DOW CORNING CORPORATION CARROLLTON, KENTUCKY SEPTEMBER 1996 U.S. DEPARTMENT OF...

471

Synthesis of 6-Methyl-9-n-propyldibenzothiophene-4-ol  

SciTech Connect (OSTI)

The material covered in this report is divided into two parts: further cyclization experiments on 1,4-diethyl-2-[(2'- methoxyphenyl)thio]benzene and its sulfone both by chemical and photochemical means, and progress toward synthesis of modified target molecule, 9-isopropyl-4-methoxy-6-methyldibenzo-thiophene. 8 refs, figs.

Eisenbraun, E.J.

1991-07-25T23:59:59.000Z

472

aberrant gene methylation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

- DSpace Summary: Optical aberrations of the human eye are currently corrected using eyeglasses, contact lenses, or surgery. We describe a fourth option: modifying the composition...

473

aberrant dna methylation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

- DSpace Summary: Optical aberrations of the human eye are currently corrected using eyeglasses, contact lenses, or surgery. We describe a fourth option: modifying the composition...

474

aberrant promoter methylation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

- DSpace Summary: Optical aberrations of the human eye are currently corrected using eyeglasses, contact lenses, or surgery. We describe a fourth option: modifying the composition...

475

aberrant methylation impairs: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

- DSpace Summary: Optical aberrations of the human eye are currently corrected using eyeglasses, contact lenses, or surgery. We describe a fourth option: modifying the composition...

476

Production and Characterization of Jatropha Oil Methyl Ester  

E-Print Network [OSTI]

pollution concern. Utilization of biodiesel produced from Jatropha oil by transesterification process is one

P. Venkateswara Rao; G. Srinivasa Rao

477

Investigation of the Atmospheric Ozone Impacts of Methyl Iodide  

E-Print Network [OSTI]

FL Kansas City, MO Lake Charles, LA Los Angeles, CAFL Kansas City, MO Lake Charles, LA Los Angeles, CA

Carter, W P L

2007-01-01T23:59:59.000Z

478

The contribution of oceanic methyl iodide to stratospheric iodine  

E-Print Network [OSTI]

horizontal wind speed and vertical transport efficiency (speed Horizontal wind speed and vertical transport CH 3 Ivertical transport. Note that for these two days high www.atmos-chem-phys.net/13/11869/2013/ horizontal wind speeds

2013-01-01T23:59:59.000Z