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Hot methanol extraction for the analysis of volatile organic chemicals in subsurface core samples from Dover Air Force Base, Delaware

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GROUND WATER MONITORING AND REMEDIATION 1997年第1期17卷 104-121页

作者： Ball, WP Xia, G Durfee, DP Wilson, RD Brown, MJ Mackay, DM William P. Ball is an assistant professor in the Department of Geography and environmental engineering at Johns Hopkins University (313 Ames Hall 3400 N. Charles St. Baltimore MD 21218). His research interests are in the physical and chemical processes that control contaminant fate in aqueous systems both in the natural environment and in engineered processes of treatment and remediation. Recent work has included both laboratory and computer modeling studies related to contaminant fate and transport in subsurface environments. Ball holds M.S. and Ph.D. degrees in environmental engineering and science from Stanford University and a B.S. degree in civil engineering from the University of Virginia. He is a registered pro-fessional engineer in the state of Virginia. Guoshou Xia is a Ph.D. candidate at Johns Hopkins University He was previously a lecturer in the Department of Civil Engineering at Southeast University in China. He received his B.S. degree in chemistry from Hefei University and his M.S. degree in environmental engineering from East China University of Chemical Technology. His current research interests are in the area ofsubsurface contaminant transport with emphasis on better understanding the nature of organic contaminant interactions with subsurface solids. Donald P. Durfee received his M.S. degree in environmental engineering from Johns Hopkins University in 1993 and is currently a Ph.D. student at Johns Hopkins. He is studying contaminant fate and transport in the subsurface and is also interested in site characterization and remediation issues. Ryan D. Wilson is a research associate and Ph.D. student in the Department of Earth Sciences at the University of Waterloo Waterloo Ontario. His research interests include field and modeling studies of semipassive remediation technologies and the behavior of gaseous tracers. Wilson received his B.Sc. in geology from the University of Alberta in 1987 and his M.Sc. in earth sciences (hydrogeology) from the University of Waterloo in 1993. Michael J. Br

The evaluation of contaminant concentrations in ground water and soil is an essential aspect of most hazardous waste remedial investigations. This paper describes methods applied toward obtaining, preserving, and analyzing subsurface samples for the determination of VOC concentrations in the saturated region of an unconfined coastal plain aquifer at Dover Air Force Base (DAFB), Delaware. The described protocol involved headspace-free subsampling of cores, field preservation of subsamples in methanol, and overnight extraction of the VOCs at elevated temperature (70 degrees C). Methanol-extracted compounds were subsequently transferred to hexane and analyzed by gas chromatography. The method was found to achieve quantitative extraction from the aquifer sands in a single step, although extraction from fine-grained and more strongly sorbing aquitard samples required multiple methanol extractions to achieve comparable recovery. An extensive set of DAFB results is presented as an indication of how these methods can be applied toward characterizing field-scale contamination with a high degree of resolution and accuracy. These data have enabled a quantitative estimate of the contaminant distribution at this site and offer valuable insight into processes of contaminant migration into the underlying aquitard. In these regards, the methods used are believed to have provided much more accurate results than could have been obtained using more commonly applied techniques.

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Novel epoxynorbornane monomers .2. Cationic photopolymerization

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MACROMOLECULES 1996年第1期29卷 439-445页

作者： Crivello, JV Narayan, R Polymer Science and Engineering Program Department of Chemistry Rensselaer Polytechnic Institute Troy New York 12180

The reactivity of a novel series of mono-, di-, and multifunctional monomers bearing the epoxynorbornane group in photoinduced cationic polymerization was determined using Fourier transform real-time infrared spectroscopy and differential scanning photocalorimetry. Comparisons were made between the monomers of this investigation containing the epoxynorbornane group with monomers of similar structure bearing epoxycyclohexane groups. Although the cationic polymerizations of the epoxynorborane functional monomers are rapid they, are slower than the aforementioned epoxycyclohexane analogues. This was attributed mainly to steric hindrance effects.

关键词： Photopolymerization Monomers Cationic polymerization Ethers Reactivity

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Novel epoxynorbornane monomers .1. Synthesis and characterization

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MACROMOLECULES 1996年第1期29卷 433-438页

作者： Crivello, JV Narayan, R Polymer Science and Engineering Program Department of Chemistry Rensselaer Polytechnic Institute Troy New York 12180

The synthesis of a series of mono-, di-, and multifunctional monomers bearing the epoxynorbornane group has been carried out. Key to their preparation is the chemoselective epoxidation of 5-vinyl-2-norbornene, which affords the 5-vinyl-exo-2,3-norbornane epoxide in high yields. Monomers were prepared using this substrate and carrying out hydrosilations to make mono-, di-, tri-, and tetrafunctional epoxides. The esterification and etherification of 5-norbornene-2-methanol with succinic acid and 1,4-butanediol gives the corresponding bisnorbornene compounds, which were epoxidized to give diepoxynorbornane monomers containing ester and ether linkages. All monomers were fully characterized by means of IR and H-1 and C-13 NMR spectroscopy and by elemental analysis.

关键词： Ethers Hydrocarbons Organic compounds Monomers Organic reactions

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THERMOCHIMICA ACTA 1996年第1-2期288卷 239-245页

作者： Karoglanian, SA Harrison, IR Department of Materials Science and Engineering Polymer Science Program The Pennsylvania State University University Park PA 16802 USA

This paper demonstrates the generation of DSC thermograms from TREF chromatograms. The reverse is clearly possible, and shows that compositional distribution information is obtainable from DSC using solution crystalli... 详细信息

关键词： TREF ULDPE short chain branching distribution

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A critical review on photoresists

A critical review on photoresists

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polymers in Optics: Physics, Chemistry, and Applications: A Critical Review 1996

作者： Ekhorutomwen, S.A. Sawan, Samuel P. Department of Chemistry Polymer Science/Plastics Engineering Program University of Massachusetts Lowell 1 University Avenue LowellMA01854 United States

A review of the current trends in microlithography is presented including the science and chemistry ofthis technology. The microelectronics technology has progressed with at an astounding rate during the pastseveral decades which is in large measure due to advances in microlithography, which is the technology used togenerate the high resolution circuit elements of today's integrated circuits. Virtually all integrated circuits are made by photolithographic techniques that utilize 365-436 nm UV radiation. But as continual advances indevice fabrication are trying the limits of conventional lithography, new strategies such as deep-UV, e-beamand x-ray are being increasingly required to provide the finer feature sizes of newer devices. This reviewexamines the progress that has been made, especially in the last decade, in the development of new resistmaterials, as well as the chemistries and technologies that have emerged, in the quest to improve sensitivity,resolution, etching resistance, etc. © (1996) 2017 SPIE.

关键词： Etching

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Development Of Miscible Blends From Intrapolymer Repulsive Interactions: Polycarbonate/Polystyrene Ionomers

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MRS Online Proceedings Library 1996年第1期461卷 13-18页

作者： R. Xie R. A. Weiss Polymer Science Program and Department of Chemical Engineering University of Connecticut CT USA

The phase behavior of blends of zinc sulfonated polystyrene (ZnSPS) and bisphenol-A polycarbonate (PC) was studied as a function of the sulfonation level and the molecular weight of the ZnSPS ionomer. The system exhibits upper critical solution temperature (UCST) behavior. The cloud point temperatures increased with increasing ZnSPS molecular weight and decreased with increasing sulfonation level. No strong interactions between ZnSPS and PC were detected by FTIR. The composition dependence of the glass transition temperatures of the miscible blends exhibited negative deviation from linear additi vity, which is consistent with no or weak interactions between ZnSPS and PC. Miscibility is believed to arise from strong repulsive interactions between the charged and uncharged species on the ionomer chain.

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A temperature rising elution fractionation study of short chain branching behavior in ultra low density polyethylene

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polymer engineering AND science 1996年第5期36卷 731-736页

作者： Karoglanian, SA Harrison, IR Polymer Science Program Department of Materials Science and Engineering The Pennsylvania State University University Park Pennsylvania 16802

The properties of ultralow-density polyethylenes (ULDPE) have been studied using temperature rising elution fractionation (TREF) as both an analytical and preparative process. TREF was employed to determine the short chain branch distribution and to fractionate the polymer into fractions that enabled further properties studies, including carbon-13 nuclear magnetic resonance, differential scanning calorimetry, dynamic mechanical thermal analysis, density gradient studies, gel permeation chromatography, analytical TREF, and some simple tensile tests. The results of these studies are reported here.

关键词： Low density polyethylenes

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Modeling of thermal and radiative aging of polymeric cable materials

Modeling of thermal and radiative aging of polymeric cable m...

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International Symposium on Electrical Insulation

作者： M.T. Shaw Yong-Ming Liu Polymer Science Program and Chemical Engineering Department University of Connecticut Storrs CT USA

It is of critical importance to safety in the nuclear power industry to estimate the lifetime of polymeric materials in an environment featuring elevated temperatures and radiation. To this end, the authors are examining the aging of polymeric materials, in cables and other components in nuclear reactor containments by comparing aging processes for a variety of materials under natural conditions with those under accelerated laboratory conditions typical of those used in qualification. The physical property data derived from naturally and artificially aged specimens are compared using three methods: (1) a traditional method; (2) activation energy from natural data alone; and (3) an internal standards method. All three methods work with the properties of the material in its aged, but usable state, and not with a failure time of the material.

关键词： polymers Radiation safety Power industry Life estimation Lifetime estimation Temperature Cables Fission reactors Accelerated aging Qualifications

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Petroleum hydrocarbon bioventing kinetics determined in soil core, microcosm and tubing cluster studies

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GROUND WATER MONITORING AND REMEDIATION 1996年第1期16卷 141-153页

作者： Moyer, EE Ostendorf, DW Richards, RJ Goodwin, S Ellen E. Moyer (ENSR Consulting and Engineering 35 Nagog Park Acton MA 01720) is a senior environmental engineer at ENSR Consulting and Engineering in Acton Massachusetts. Her research interests include bioremediation air sparging soil venting and analytical modeling of subsurface contamination. Dr. Moyer is a registered professional engineer with an M.S. in environmental engineering and a Ph.D. in civil engineering from the University of Massachusetts at Amherst and is a member of the National Ground Water Association (NGWA) and the American Society of Civil Engineers. David W. Ostendorf (Civil Engineering Department University of Massachusetts Amherst MA 01003) is an associate professor in the Environmental Engineering Program of the Civil Engineering Department of the University of Massachusetts at Amherst. His research interests include unconfined aquifer contamination hazardous waste site remediation and analytical modeling of problems in environmental fluid mechanics. Dr. Ostendorf is a registered professional engineer and a member of the American Geophysical Union American Society of Civil Engineers Soil Science Society of America Water Pollution Control Federation Association of Environmental Engineering Professors and NGWA. Robin J. Richards (Department of Microbiology University of Massachusetts Amherst MA 01003) is a doctoral student in microbiology at the University of Massachusetts at Amherst. Her research interests include synthesis and biodegradation of microbially produced polymers as well as bioremediation of petroleum contamination in soil and ground water. She has a B.S. in civil engineering from City College of New York and an M.S. in environmental engineering from the University of Massachusetts at Amherst. Steve Goodwin (Microbiology Department University of Massachusetts Amherst MA 01003) is an associate professor in the Department of Microbiology of the University of Massachusetts at Amherst. His research interests include microbial ecology anaerobic digestion and

Aerobic biodegradation of vapor-phase petroleum hydrocarbons was evaluated in an intact soil core from the site of an aviation gasoline release. An unsaturated zone soil core was subjected to a flow of nitrogen gas, oxygen, water vapor and vapor-phase hydrocarbons in a configuration analogous to a biofilter or an in situ bioventing or sparging situation. The vertical profiles of vapor-phase hydrocarbon concentration in the soil core were determined by gas chromatography of vapor samples. Biodegradation reduced low influent hydrocarbon concentrations by 45 to 92 percent over a 0.6-m interval of an intact soil core. The estimated total hydrocarbon concentration was reduced by 75 percent from 26 to 7 parts per million. Steady-state concentrations were input to a simple analytical model balancing advection and first-order biodegradation of hydrocarbons. First-order rate constants for the major hydrocarbon compounds were used to calibrate the model to the concentration profiles. Rate constants for the seven individual hydrocarbon compounds varied by a factor of 4. Compounds with lower molecular weights, fewer methyl groups, and no quaternary carbons tended to have higher rate constants. the fist-order rate constants were consistent with kinetic parameters determined from both microcosm and tubing cluster studies at the field site.

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Specific interactions and miscibility of blends of poly(ε-caprolactam) and sulfonated PEEK ionomer

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Journal of polymer science 1996年第10期34卷

作者： Xinya Lu R. A. Weiss Polymer Science Program and Department of Chemical Engineering University of Connecticut Storrs Connecticut 06269-3136

Sulfonation of poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene), PEEK, improves its miscibility with poly(ϵ-caprolactam), Nylon-6 ( N 6). This article describes the thermal transitions and the specific interactions that occur for blends of the free acid derivative (H-SPEEK) and the lithium (Li-SPEEK) and zinc salts (Zn-SPEEK) of sulfonated PEEK (19.2 mol % sulfonation) with N 6. The interactions responsible for miscibility were characterized by Fourier transform infrared (FTIR) spectroscopy. For blends of H-SPEEK and N 6, miscibility is due to hydrogen bonding between the sulfonic acid and the amide group. For blends of N 6 with the salts of SPEEK the specific interaction involves an ion-dipole complex of Li + with the amide carbonyl or Zn 2+ with the amide nitrogen. The relative strengths of the intermolecular interactions for the three types of blends increased as the cation was varied in the order: H + < Li + < Zn 2+ , and the T g s of the mixtures increased in the same order. © 1996 John Wiley & Sons, Inc.

关键词： Ionomers polyamides PEEK sulfonation complexation blends

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