(1-Adamantyl)methyl glycidyl ether: a versatile building block for living polymerization.

Science.gov (United States)

Moers, Christian; Wrazidlo, Robert; Natalello, Adrian; Netz, Isabelle; Mondeshki, Mihail; Frey, Holger

2014-06-01

(1-Adamantyl)methyl glycidyl ether (AdaGE) is introduced as a versatile monomer for oxyanionic polymerization, enabling controlled incorporation of adamantyl moieties in aliphatic polyethers. Via copolymerization with ethoxyethyl glycidyl ether (EEGE) and subsequent cleavage of the acetal protection groups of EEGE, hydrophilic linear polyglycerols with an adjustable amount of pendant adamantyl moieties are obtained. The adamantyl unit permits control over thermal properties and solubility profile of these polymers (LCST). Additionally, AdaGE is utilized as a termination agent in carbanionic polymerization, affording adamantyl-terminated polymers. Using these structures as macroinitiators for the polymerization of ethylene oxide affords amphiphilic, in-chain adamantyl-functionalized block copolymers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DERMAL, ORAL AND INHALATION PHARMACOKINETICS OF METHYL TERTIARY-BUTYL ETHER (MTBE) IN HUMAN VOLUNTEERS

Science.gov (United States)

Methyl tertiary butyl ether (MTBE), a gasoline additive used to increase octane and reduce carbon monoxide emissions and ozone precursors, has contaminated drinking water and can lead to exposure by oral, inhalation, and dermal routes. To determine its dermal, oral, and inhal...

Photosynthesis involvement in the mechanism of action of diphenyl ether herbicides.

Science.gov (United States)

Ensminger, M P; Hess, F D

1985-05-01

Photosynthesis is not required for the toxicity of diphenyl ether herbicides, nor are chloroplast thylakoids the primary site of diphenyl ether herbicide activity. Isolated spinach (Spinacia oleracea L.) chloroplast fragments produced malonyl dialdehyde, indicating lipid peroxidation, when paraquat (1,1'-dimethyl-4,4'-bipyridinium ion) or diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] were added to the medium, but no malonyl dialdehyde was produced when chloroplast fragments were treated with the methyl ester of acifluorfen (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid), oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene], or MC15608 (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-chlorobenzoate). In most cases the toxicity of acifluorfen-methyl, oxyfluorfen, or MC15608 to the unicellular green alga Chlamydomonas eugametos (Moewus) did not decrease after simultaneous treatment with diuron. However, diuron significantly reduced cell death after paraquat treatment at all but the highest paraquat concentration tested (0.1 millimolar). These data indicate electron transport of photosynthesis is not serving the same function for diphenyl ether herbicides as for paraquat. Additional evidence for differential action of paraquat was obtained from the superoxide scavenger copper penicillamine (copper complex of 2-amino-3-mercapto-3-methylbutanoic acid). Copper penicillamine eliminated paraquat toxicity in cucumber (Cucumis sativus L.) cotyledons but did not reduce diphenyl ether herbicide toxicity.

Risicogrenzen voor MTBE (Methyl tertiair-Butyl Ether) in bodem, sediment, grondwater, oppervlaktewater en voor drinkwaterbereiding

NARCIS (Netherlands)

Swartjes FA; Baars AJ; Fleuren RHLJ; Otte PF; LER

2004-01-01

Recentelijk is politieke commotie ontstaan ten gevolge van de mogelijke schadelijke gezondheidseffecten van Methyl tertiair-Butyl Ether (MTBE). Dit was reden voor het ministerie van VROM om het RIVM te verzoeken risicogrenzen voor MTBE in bodem, sediment, grondwater, oppervlaktewater, drinkwater en

Process for producing high purity isoolefins and dimers thereof by dissociation of ethers

Science.gov (United States)

Smith, L.A. Jr.; Jones, E.M. Jr.; Hearn, D.

1984-05-08

Alkyl tertiary butyl ether or alkyl tertiary amyl ether is dissociated by vapor phase contact with a cation acidic exchange resin at temperatures in the range of 150 to 250 F at LHSV of 0.1 to 20 to produce a stream consisting of unreacted ether, isobutene or isoamylene and an alcohol corresponding to the alkyl radical. After the alcohol is removed, the ether/isoolefin stream may be fractionated to obtain a high purity isoolefin (99+%) or the ether/isoolefin stream can be contacted in liquid phase with a cation acidic exchange resin to selectively dimerize the isoolefin in a highly exothermic reaction, followed by fractionation of the dimerization product to produce high purity diisoolefin (97+%). In the case where the alkyl is C[sub 3] to C[sub 6] and the corresponding alcohol is produced on dissociation of the ether, combined dissociation-distillation may be carried out such that isoolefin is the overhead product and alcohol the bottom. 2 figs.

Photosynthesis Involvement in the Mechanism of Action of Diphenyl Ether Herbicides 1

Science.gov (United States)

Ensminger, Michael P.; Hess, F. Dan

1985-01-01

Photosynthesis is not required for the toxicity of diphenyl ether herbicides, nor are chloroplast thylakoids the primary site of diphenyl ether herbicide activity. Isolated spinach (Spinacia oleracea L.) chloroplast fragments produced malonyl dialdehyde, indicating lipid peroxidation, when paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) or diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] were added to the medium, but no malonyl dialdehyde was produced when chloroplast fragments were treated with the methyl ester of acifluorfen (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid), oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene], or MC15608 (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-chlorobenzoate). In most cases the toxicity of acifluorfen-methyl, oxyfluorfen, or MC15608 to the unicellular green alga Chlamydomonas eugametos (Moewus) did not decrease after simultaneous treatment with diuron. However, diuron significantly reduced cell death after paraquat treatment at all but the highest paraquat concentration tested (0.1 millimolar). These data indicate electron transport of photosynthesis is not serving the same function for diphenyl ether herbicides as for paraquat. Additional evidence for differential action of paraquat was obtained from the superoxide scavenger copper penicillamine (copper complex of 2-amino-3-mercapto-3-methylbutanoic acid). Copper penicillamine eliminated paraquat toxicity in cucumber (Cucumis sativus L.) cotyledons but did not reduce diphenyl ether herbicide toxicity. PMID:16664206

Searching for trans ethyl methyl ether in Orion KL.

Science.gov (United States)

Tercero, B; Cernicharo, J; López, A; Brouillet, N; Kolesniková, L; Motiyenko, R A; Margulès, L; Alonso, J L; Guillemin, J-C

2015-10-01

We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH 3 CH 2 OCH 3 , through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH 3 CH 2 CH 2 OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 10 15 cm -2 and ≤(1.0 ± 0.2)× 10 15 cm -2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH 3 OCOH, CH 3 CH 2 OCOH, CH 3 OCH 3 , CH 3 OH, and CH 3 CH 2 OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N (CH 3 OCH 3 )/ N (tEME) ≥ 150 in the compact ridge of Orion.

QSPR models of n-octanol/water partition coefficients and aqueous solubility of halogenated methyl-phenyl ethers by DFT method.

Science.gov (United States)

Zeng, Xiao-Lan; Wang, Hong-Jun; Wang, Yan

2012-02-01

The possible molecular geometries of 134 halogenated methyl-phenyl ethers were optimized at B3LYP/6-31G(*) level with Gaussian 98 program. The calculated structural parameters were taken as theoretical descriptors to establish two new novel QSPR models for predicting aqueous solubility (-lgS(w,l)) and n-octanol/water partition coefficient (lgK(ow)) of halogenated methyl-phenyl ethers. The two models achieved in this work both contain three variables: energy of the lowest unoccupied molecular orbital (E(LUMO)), most positive atomic partial charge in molecule (q(+)), and quadrupole moment (Q(yy) or Q(zz)), of which R values are 0.992 and 0.970 respectively, their standard errors of estimate in modeling (SD) are 0.132 and 0.178, respectively. The results of leave-one-out (LOO) cross-validation for training set and validation with external test sets both show that the models obtained exhibited optimum stability and good predictive power. We suggests that two QSPR models derived here can be used to predict S(w,l) and K(ow) accurately for non-tested halogenated methyl-phenyl ethers congeners. Copyright © 2011 Elsevier Ltd. All rights reserved.

INHALATION EXPOSURE TO METHYL TERT-BUTYL ETHER (MTBE) AND DIBROMOCHLOROMETHANE (DBCM) USING CONTINUOUS BREATH ANALYSIS

Science.gov (United States)

The oxygenate methyl tert-butyl ether (MTBE) has been added to gasoline to help meet national ambient air quality standards in those parts of the U.S. that are non-compliant for carbon monoxide. Although MTBE has provided important health benefits in terms of reduced haza...

Thermodynamics of Hydrogen Production from Dimethyl Ether Steam Reforming and Hydrolysis

Energy Technology Data Exchange (ETDEWEB)

T.A. Semelsberger

2004-10-01

The thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the process of dimethyl ether (DME) steam reforming were investigated as a function of steam-to-carbon ratio (0-4), temperature (100 C-600 C), pressure (1-5 atm), and product species: acetylene, ethanol, methanol, ethylene, methyl-ethyl ether, formaldehyde, formic acid, acetone, n-propanol, ethane and isopropyl alcohol. Results of the thermodynamic processing of dimethyl ether with steam indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure was observed to shift the equilibrium toward the reactants; increasing the pressure from 1 atm to 5 atm decreased the conversion of dimethyl ether from 99.5% to 76.2%. The order of thermodynamically stable products in decreasing mole fraction was methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol--formaldehyde, formic acid, and acetylene were not observed. The optimal processing conditions for dimethyl ether steam reforming occurred at a steam-to-carbon ratio of 1.5, a pressure of 1 atm, and a temperature of 200 C. Modeling the thermodynamics of dimethyl ether hydrolysis (with methanol as the only product considered), the equilibrium conversion of dimethyl ether is limited. The equilibrium conversion was observed to increase with temperature and steam-to-carbon ratio, resulting in a maximum dimethyl ether conversion of approximately 68% at a steam-to-carbon ratio of 4.5 and a processing temperature of 600 C. Thermodynamically, dimethyl ether processed with steam can produce hydrogen-rich fuel-cell feeds--with hydrogen concentrations exceeding 70%. This substantiates dimethyl ether as a viable source of hydrogen for PEM fuel cells.

Morphology in binary blends of poly(vinyl methyl ether) and epsilon-caprolactone-trimethylene carbonate diblock copolymer

NARCIS (Netherlands)

Luyten, MC; Bogels, EJF; vanEkenstein, GORA; tenBrinke, G; Bras, W; Komanschek, BE; Ryan, AJ

The morphology of symmetric diblock copolymer of epsilon-caprolactone (PCL) and trimethylene carbonate (PTMC), in blends with poly(vinyl methyl ether) (PVME) is investigated with (modulated) differential scanning calorimetry (d.s.c.), time resolved small angle (SAXS) and wide angle (WAXS) X-ray

Morphology in binary blends of poly(vinyl methyl ether) and ε-caprolactone-trimethylene carbonate diblock copolymer

NARCIS (Netherlands)

Luyten, M.C.; Bögels, E.J.F.; Alberda van Ekenstein, G.O.R.; Brinke, G. ten; Bras, W.; Komanschek, B.E.; Ryan, A.J.

1997-01-01

The morphology of symmetric diblock copolymer of ε-caprolactone (PCL) and trimethylene carbonate (PTMC), in blends with poly(vinyl methyl ether) (PVME) is investigated with (modulated) differential scanning calorimetry (d.s.c.), time resolved small angle (SAXS) and wide angle (WAXS) X-ray

Thermodynamic and Kinetic Behavior of the Polystyrene/Poly(vinyl methyl ether) Blend as Studied by Excimer Fluorescence.

Science.gov (United States)

1986-01-02

AD-A±63 895 THERMODYNAMIC AND KINETIC BEHAVIOR OF THE / POLYSTYRENE/POLY(YINYL METHYL E..(U) STANFORD UNIY CALIFDEPT OF CHEMICAL ENGINEERING C N...Polystyrene/Poly(vinyl methyl ether) Blend 7. DEcFRMN 81 toOR 30USptE8 00~ as Studied by Excimer Fluorescence 6 EFRIGOG EOTNME *AUTHOR() a. CONTRACT OR GRANT...werea fondoare ihemoriisof * ~ Ex e sp fluodecositionsdu to deud Gen e and hoog Pinus Florsneis shownhase migrationprocSECURITY CLASIFICTIO OFd

U.S. Geological Survey laboratory method for methyl tert-Butyl ether and other fuel oxygenates

Science.gov (United States)

Raese, Jon W.; Rose, Donna L.; Sandstrom, Mark W.

1995-01-01

Methyl tert-butyl ether (MTBE) was found in shallow ground-water samples in a study of 8 urban and 20 agricultural areas throughout the United States in 1993 and 1994 (Squillace and others, 1995, p. 1). The compound is added to gasoline either seasonally or year round in many parts of the United States to increase the octane level and to reduce carbon monoxide and ozone levels in the air. The U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL), near Denver, uses state-of-the-art technology to analyze samples for MTBE as part of the USGS water-quality studies. In addition, the NWQL offers custom analyses to determine two other fuel oxygenates--ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME). The NWQL was not able to obtain a reference standard for tert-amyl ethyl ether (TAEE), another possible fuel oxygenate (Shelley and Fouhy, 1994, p. 63). The shallow ground-water samples were collected as part of the USGS National Water-Quality Assessment Program. These samples were collected from 211 urban wells or springs and 562 agricultural wells sampled by the USGS in 1993 and 1994. The wells were keyed to specific land-use areas to assess the effects of different uses on ground-water quality (Squillace and others, 1995, p. 2). Ground-water samples were preserved on site to pH less than or equal to 2 with a solution of 1:1 hydrochloric acid. All samples were analyzed at the NWQL within 2 weeks after collection. The purpose of this fact sheet is to explain briefly the analytical method implemented by the USGS for determining MTBE and other fuel oxygenates. The scope is necessarily limited to an overview of the analytical method (instrumentation, sample preparation, calibration and quantitation, identification, and preservation of samples) and method performance (reagent blanks, accuracy, and precision).

Biodegradability of fuel-ethers in environment; Biodegradabilite des ethers-carburants dans l'environnement

Energy Technology Data Exchange (ETDEWEB)

Fayolle-Guichard, F

2005-04-01

Fuel ethers (methyl tert-butyl ether or MTBE, ethyl tert-butyl ether or ETBE and tert-amyl methyl ether or TAME have been used as gasoline additives since about twenty years in order to meet the requirements for the octane index and to limit the polluting emission in exhaust pipe gas (unburnt hydrocarbons and carbon monoxide). The high water solubility and the poor biodegradability of these compounds make them pollutants frequently encountered in aquifers. The present manuscript summarizes the knowledge concerning the biodegradability of fuel ethers obtained both at IFP and during collaborations with the Pasteur Institute (Paris), the Biotechnology Research Institute (Montreal, Canada) and the Center for Environmental Biotechnology (University of Tennessee, USA). Rhodococcus ruber IFP 2001 and Mycobacterium austroafricanum IFP 2012, two microorganisms isolated at IFP for their ability to grow, respectively, on ETBE and MTBE, were studied in order to determine the intermediates produced during MTBE and ETBE biodegradation and the enzymes required for each biodegradation step, thus allowing us to propose MTBE and ETBE catabolic pathways. A proteomic approach, from the protein induced during the degradation of ETBE or MTBE to the genes encoding these different enzymes, was carried out. The isolation of such genes is required:1) to use them for help in determining the bio-remediation capacities in polluted aquifers (DNA micro-arrays), 2) to monitor the microorganisms isolated for their degradative capacities during bio-remediation processes (fluorescent in situ hybridization or FISH) and 3) to create new tools for the detection and the quantification of ETBE or MTBE in contaminated aquifers (bio-sensor). The manuscript also describes the different ways for the adaptation of microorganisms to the presence of a xenobiotic compound. (author)

Geissoschizine methyl ether N-oxide, a new alkaloid with antiacetylcholinesterase activity from Uncaria rhynchophylla.

Science.gov (United States)

Jiang, Wei-Wei; Su, Jia; Wu, Xing-De; He, Juan; Peng, Li-Yan; Cheng, Xiao; Zhao, Qin-Shi

2015-01-01

Geissoschizine methyl ether N-oxide, a new oxindole alkaloid, along with 14 known alkaloids, was isolated from the aerial part of Uncaria rhynchophylla. Their structures were identified by comprehensive spectral methods, including 2D NMR experiments, and confirmed by comparing with the literature data. In vitro acetylcholinesterase (AChE) inhibitory activity assay showed that the new compound exhibited anti-AChE activity with IC₅₀ value of 23.4 μM.

Thermally reversible cross-linked poly(ether-urethanes

Directory of Open Access Journals (Sweden)

V. Gaina

2013-07-01

Full Text Available Cross-linked poly(ether-urethanes were prepared by Diels-Alder (DA reaction of the furan-containing poly(ether-urethane to bismaleimides and showed thermal reversibility evidenced by differential scanning calorimetry and attenuated total reflectance in conjunction with Fourier transform infrared spectroscopy (ATR-FTIR. The furan-containing poly(ether-urethanes were synthesized by the polyaddition reaction of 1,6-hexamethylene diisocyanate (HMDI or 4,4'- dibenzyl diisocyanate (DBDI to poly(tetramethylene ether glycol (PTMEG having Mn = 250, 650, 1000, 1500 and 2000 and 2-[N,N-bis(2-methyl-2-hydroxyethylamino]furfuryl as chain extender by the solution prepolymer method. The molar ratio of isocyanate: PTMEG:chain extender varied from 2:1:1 to 4:1:3, which produces a molar concentration of furyl group ranging between 3.65•10–4 and 1.25•10–3 mol/g.

Searching for trans ethyl methyl ether in Orion KL★,★★

Science.gov (United States)

Tercero, B.; Cernicharo, J.; López, A.; Brouillet, N.; Kolesniková, L.; Motiyenko, R. A.; Margulès, L.; Alonso, J. L.; Guillemin, J.-C.

2015-01-01

We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 1015 cm−2 and ≤(1.0 ± 0.2)× 1015 cm−2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion. PMID:26869726

Biodegradability of fuel-ethers in environment; Biodegradabilite des ethers-carburants dans l'environnement

Energy Technology Data Exchange (ETDEWEB)

Fayolle-Guichard, F.

2005-04-01

Fuel ethers (methyl tert-butyl ether or MTBE, ethyl tert-butyl ether or ETBE and tert-amyl methyl ether or TAME have been used as gasoline additives since about twenty years in order to meet the requirements for the octane index and to limit the polluting emission in exhaust pipe gas (unburnt hydrocarbons and carbon monoxide). The high water solubility and the poor biodegradability of these compounds make them pollutants frequently encountered in aquifers. The present manuscript summarizes the knowledge concerning the biodegradability of fuel ethers obtained both at IFP and during collaborations with the Pasteur Institute (Paris), the Biotechnology Research Institute (Montreal, Canada) and the Center for Environmental Biotechnology (University of Tennessee, USA). Rhodococcus ruber IFP 2001 and Mycobacterium austroafricanum IFP 2012, two microorganisms isolated at IFP for their ability to grow, respectively, on ETBE and MTBE, were studied in order to determine the intermediates produced during MTBE and ETBE biodegradation and the enzymes required for each biodegradation step, thus allowing us to propose MTBE and ETBE catabolic pathways. A proteomic approach, from the protein induced during the degradation of ETBE or MTBE to the genes encoding these different enzymes, was carried out. The isolation of such genes is required:1) to use them for help in determining the bio-remediation capacities in polluted aquifers (DNA micro-arrays), 2) to monitor the microorganisms isolated for their degradative capacities during bio-remediation processes (fluorescent in situ hybridization or FISH) and 3) to create new tools for the detection and the quantification of ETBE or MTBE in contaminated aquifers (bio-sensor). The manuscript also describes the different ways for the adaptation of microorganisms to the presence of a xenobiotic compound. (author)

Miconidin and miconidin methyl ether from Primula obconica Hance: new allergens in an old sensitizer

DEFF Research Database (Denmark)

Paulsen, Evy; Christensen, Lars P; Andersen, Klaus Ejner

2006-01-01

. obconica. 12 primin-positive persons were patch tested with miconidin 0.01% petrolatum (pet.), miconidin in 96% ethanol incorporated into 0.01% pet., and miconidin methyl ether 1.0% pet. All persons were positive to miconidin 0.01% pet., with the strength of reactions very similar to those...

SYNTHESIS OF METHYL TERT-BUTYL ETHER CATALYZED BY ACIDIC ION-EXCHANGE RESINS - INFLUENCE OF THE PROTON ACTIVITY

NARCIS (Netherlands)

PANNEMAN, HJ; BEENACKERS, AACM

1995-01-01

The catalytic activity of various strong acid ion-exchange resins on the synthesis of methyl tert-butyl ether (MtBE) from methanol and isobutene has been investigated. Relative to Amberlyst 15, Kastel CS 381 and Amberlyst CSP have similar rate constants, whereas Duolite ES 276 and Amberlyst XE 307

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

International Nuclear Information System (INIS)

Salanitro, J.; Wisniewski, H.; McAllister, P.

1995-01-01

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

DEVELOPMENT OF PHYSIOLOGICAL-BASED PHARMACOKINETIC MODEL FOR DERMAL ABSORPTION NAD PENETRATION OF METHYL TERTIARY BUTYL ETHER IN HUMANS

Science.gov (United States)

Background: Methyl tertiary butyl ether (MTBE) is a volatile organic chemical that is added to gasoline as an octane booster and to reduce vehicular emissions of carbon monoxide. MTBE is introduced into the environment through fuel spills, leakage of storage tanks, and evaporat...

TOXICITY OF METHYL-TERT BYTYL ETHER (MTBE) TO PLANTS (AVENA SATIVA, ZEA MAYS, TRITICUM AESTIVUM, AND LACTUCA SATIVA)

Science.gov (United States)

Effects of Methyl tert-butyl ether (MTBE) on the germination of seeds and growth of the plant were studied in some laboratory experiments. Test plants were wild oat (Avena sative), sweet corn (Zea mays), wheat (Triticum aestivum), and lettuce (Lactuca sativa). Seed germination,...

TAME (tertiary-amyl-methyl ether) gasoline additive production process development; Desenvolvimento do processo de producao de TAME-aditivo para gasolina

Energy Technology Data Exchange (ETDEWEB)

Lovisi, Humberto [Petroflex Industria e Comercio S.A., Duqye de Caxias, RJ (Brazil); Piccoli, Ricardo [COPESUL, Companhia Petroquimica do Sul, Triunfo, RS (Brazil)

1992-12-31

PETROFLEX and COPESUL jointly developed a TAME production process. Tertiary-amyl-methyl ether (TAME) is obtained by the methoxylation of isoamylenes (2-methyl-1-butene and 2-methyl-2-butene) in a C{sub s} cut over a sulfonic acid resin. Process was developed on the basis of pilot plant and batch experiments. A simplified process flow-sheet and pilot plant data are presented. Isoamylenes conversions higher than 70% were achieved with low by-products formation. (author) 22 refs., 2 figs., 2 tabs.

TAME (tertiary-amyl-methyl ether) gasoline additive production process development; Desenvolvimento do processo de producao de TAME-aditivo para gasolina

Energy Technology Data Exchange (ETDEWEB)

Lovisi, Humberto [Petroflex Industria e Comercio S.A., Duqye de Caxias, RJ (Brazil); Piccoli, Ricardo [COPESUL, Companhia Petroquimica do Sul, Triunfo, RS (Brazil)

1993-12-31

PETROFLEX and COPESUL jointly developed a TAME production process. Tertiary-amyl-methyl ether (TAME) is obtained by the methoxylation of isoamylenes (2-methyl-1-butene and 2-methyl-2-butene) in a C{sub s} cut over a sulfonic acid resin. Process was developed on the basis of pilot plant and batch experiments. A simplified process flow-sheet and pilot plant data are presented. Isoamylenes conversions higher than 70% were achieved with low by-products formation. (author) 22 refs., 2 figs., 2 tabs.

Volumetric Behaviour of the Ternary System (Methyl Tert-butyl ether + Methylbenzene + Butan-1-ol) and Its Binary sub-System (Methyl Tert-Butyl Ether + Butan-1-ol) within the Temperature Range (298.15–328.15) K

Czech Academy of Sciences Publication Activity Database

Morávková, Lenka; Troncoso, J.; Škvorová, M.; Havlica, Jaromír; Petrus, P.; Sedláková, Zuzana

2015-01-01

Roč. 90, NOV 2015 (2015), s. 59-70 ISSN 0021-9614 R&D Projects: GA ČR(CZ) GAP105/12/0664; GA MŠk(CZ) LD14094 Grant - others:GNIL(IT) 408 REGALIs (CN2012/120) Institutional support: RVO:67985858 Keywords : methylbenzene * density * methyl-tert-butyl ether Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.196, year: 2015

Model-based analysis of CO2 revalorization for di-methyl ether synthesis driven by solar catalytic reforming

International Nuclear Information System (INIS)

Luu, Minh Tri; Milani, Dia; Sharma, Manish; Zeaiter, Joseph; Abbas, Ali

2016-01-01

Highlights: • Solar energy applied for synthesis of di-methyl ether via dry methane reforming. • Concentrated solar energy at receiver reaction zone for syngas generation. • H 2 /CO molar ratio of ‘1’ is maintained via two alternative processing routes. • Assessed three days of operation under different insolation levels. • Improvements of 18.7%, 32.2% and 20% for methane, energy and CO 2 emission intensities. - Abstract: The application of solar energy is investigated for the synthesis of di-methyl ether (DME) in a solar irradiated dry methane reformer (DMR). Solar radiations are concentrated onto a receiver and distributed to the reaction zone to provide necessary energy for syngas (CO and H 2 ) generation. In order to maintain a H 2 /CO molar ratio of ‘1’, as required in DME synthesis, the produced syngas is processed via two alternative routes: solar reformer coupled in parallel with a non-solar reformer (SoR-NSoR) and solar reformer integrated with a water-gas shift reactor (SoR-WGS). It is found that steam methane reforming (SMR) is the most suitable methodology when coupled with a solar reformer due to high H 2 content in the SMR syngas. Further performance analysis is conducted by simulating three days of operation under different insolation levels (high, medium and low irradiations). The simulation results showed that the SoR-WGS configuration produces the highest improvements of 18.7%, 32.2% and 20% in terms of methane, energy and CO 2 emission intensity respectively. This enhanced process performance originates from the exothermic nature of the WGS process which helps in controlling the overall syngas composition, whereas the SoR-NSoR requires fossil based thermal energy to drive the NSoR process to similar control targets. This promising improvement of all metrics in SoR-WGS may stimulate in-depth techno-economic feasibility of this unique solar integration for DME and other synthetic fuels production.

INTERACTION OF METHYL-TERT BUTYL ETHER AND WATER STRESS ON SEED GERMINATION AND SEEDLING GROWTH IN SOIL MICROCOSMS

Science.gov (United States)

Methyl tert-butyl ether (MTBE) is a widespread contaminant in surface and ground water in the United States. Frequently irrigation is used to water fields to germinate planted seeds and sustain plant growth. A likely possibility exists that water used may have some MTBE. Our s...

Overview of technologies for removal of methyl tert-butyl ether (MTBE) from water.

Science.gov (United States)

Levchuk, Irina; Bhatnagar, Amit; Sillanpää, Mika

2014-04-01

Wide use of methyl tert-butyl ether (MTBE) as fuel oxygenates leads to worldwide environment contamination with this compound basically due to fuel leaks from storage or pipelines. Presence of MTBE in drinking water is of high environmental and social concern. Existing methods for MTBE removal from water have a number of limitations which can be possibly overcome in the future with use of emerging technologies. This work aims to provide an updated overview of recent developments in technologies for MTBE removal from water. Copyright © 2014. Published by Elsevier B.V.

DFT study on the adsorption of diethyl, ethyl methyl, and dimethyl ethers on the surface of gallium doped graphene

Energy Technology Data Exchange (ETDEWEB)

Shokuhi Rad, Ali, E-mail: a.shokuhi@gmail.com [Department of Chemical Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Sani, Emad; Binaeian, Ehsan [Department of Chemical Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Peyravi, Majid; Jahanshahi, Mohsen [Faculty of Chemical Engineering, Babol University of Technology, Babol (Iran, Islamic Republic of)

2017-04-15

Highlights: • Adsorption of three ether molecules on the surface of Ga-doped graphene has been investigated. • High degree of adsorption for all analytes is found. • Ga-doped graphene shows p-type semiconductor property upon adsorption of ether molecules. - Abstract: In this study, we used density functional theory (DFT) to search on the adsorption properties of three important compounds of ether family; diethyl ether (DEE), ethyl methyl ether (EME), and dimethyl ether (DME) on the surface of Gallium doped graphene (GaG). We used three functionals (B3LYP, wb97xd, and MPW1PW91) for optimization and calculation of adsorption energy. After fully optimization, we scrutinized on the charge allocations on the adsorbed ethers as well as GaG (at the area of interaction) based on natural bond orbitals (NBO). Besides, we have calculated the amount of charge transfer upon adsorption of each analyte. We revel that GaG is an ideal adsorbent for chemisorption of all above-mentioned ethers. There is a little difference between the values of adsorption; −123.5, −120, and −118.3 kJ/mol (based on wb97xd) for DEE, EME, and DME, respectively. We found significant changes in the electronic structure of both adsorbent and adsorbate upon adsorption. Moreover, results of charge analyses confirm GaG is a p-type semiconductor.

DFT study on the adsorption of diethyl, ethyl methyl, and dimethyl ethers on the surface of gallium doped graphene

International Nuclear Information System (INIS)

Shokuhi Rad, Ali; Sani, Emad; Binaeian, Ehsan; Peyravi, Majid; Jahanshahi, Mohsen

2017-01-01

Highlights: • Adsorption of three ether molecules on the surface of Ga-doped graphene has been investigated. • High degree of adsorption for all analytes is found. • Ga-doped graphene shows p-type semiconductor property upon adsorption of ether molecules. - Abstract: In this study, we used density functional theory (DFT) to search on the adsorption properties of three important compounds of ether family; diethyl ether (DEE), ethyl methyl ether (EME), and dimethyl ether (DME) on the surface of Gallium doped graphene (GaG). We used three functionals (B3LYP, wb97xd, and MPW1PW91) for optimization and calculation of adsorption energy. After fully optimization, we scrutinized on the charge allocations on the adsorbed ethers as well as GaG (at the area of interaction) based on natural bond orbitals (NBO). Besides, we have calculated the amount of charge transfer upon adsorption of each analyte. We revel that GaG is an ideal adsorbent for chemisorption of all above-mentioned ethers. There is a little difference between the values of adsorption; −123.5, −120, and −118.3 kJ/mol (based on wb97xd) for DEE, EME, and DME, respectively. We found significant changes in the electronic structure of both adsorbent and adsorbate upon adsorption. Moreover, results of charge analyses confirm GaG is a p-type semiconductor.

Enhancement of methyl tert-butyl ether degradation by the addition of readily metabolizable organic substrates

International Nuclear Information System (INIS)

Chen Dongzhi; Chen Jianmeng; Zhong Weihong

2009-01-01

Supplements with readily metabolizable organic substrates were investigated to increase the biomass and enhance degradation of methyl tert-butyl ether (MTBE) due to the low biomass yield of MTBE which has been one of the factors for low-rate MTBE degradation. The influence of various organic substrates on the rate of aerobic degradation of methyl tert-butyl ether (MTBE) by Methylibium petroleiphilum PM1 was investigated, and only yeast extract (YE), beef extract and tryptone exhibited stimulatory effect. With the concentration of each substrate being 100 mg/L, the average MTBE removal rate could increase to 1.29, 1.20 and 1.04 mg/(L h), respectively, in comparison with 0.71 mg/(L h) when carried out in medium without addition. The stimulatory effects of YE addition, as well as induction period required by MTBE degradation, varied dramatically with the storage conditions, pre-culture medium and concentrations of the inoculums. The extent of stimulatory effects of YE might be closely related to the proportion of induction period in the total time of MTBE-degradation. The removal efficiency increased from about 50% to 90.5% with the addition of YE in a packed-bed reactor loaded with calcium alginate immobilized cells.

Biodegradation of methyl tert-butyl ether by Kocuria sp.

Directory of Open Access Journals (Sweden)

Kiković Dragan D.

2012-01-01

Full Text Available Methyl tert-butyl ether (MTBE has been used to replace the toxic compounds from gasoline and to reduce emission of air pollutants. Due to its intensive use, MTBE has become one of the most important environment pollutants. The aim of this paper is isolation and identification of the bacteria from wastewater sample of “HIP Petrohemija” Pančevo (Serbia, capable of MTBE biodegradation. The results of the investigation showed that only the bacterial isolate 27/1 was capable of growth on MTBE. The result of sequence analyzes of 16S rDNA showed that this bacterial isolate belongs to the Kocuria sp. After the incubation period of 86 days, the degradation rates of initial MTBE concentration of 25 and 125 μg/ml were 55 and 36%, respectively. These results indicated that bacteria Kocuria sp. is successfully adapted on MTBE and can be potentially used in bioremediation of soils and waters contaminated with MTBE.

Synthesis and properties of the metallo-supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]·AgNO3: Ag+/Cu2+ ion exchange and effective antibacterial activity

KAUST Repository

Xu, Feng

2014-01-01

The commercial polymeric anhydride poly(methyl vinyl ether-alt-maleic anhydride) (PVM/MA) is converted by reaction with NaOH to give poly(methyl vinyl ether-alt-mono-sodium maleate) (PVM/Na-MA). By addition of AgNO 3-solution, the formation of the silver(i) supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]·AgNO 3 is reported. Freeze-dried samples of the hydrogel show a mesoporous network of polycarboxylate ligands that are crosslinked by silver(i) cations. In the intact hydrogel, ion-exchange studies are reported and it is shown that Ag+ ions can be exchanged by copper(ii) cations without disintegration of the hydrogel. The silver(i) hydrogel shows effective antibacterial activity and potential application as burn wound dressing. © the Partner Organisations 2014.

Williamson alkylation approach to the synthesis of poly(alkyl vinyl ether) copolymers

International Nuclear Information System (INIS)

Markova, D.; Christova, D.; Velichkova, R.

2008-01-01

A method for synthesis of poly(alkyl vinyl ether-co-vinyl alcohol) copolymers was developed based on the Williamson's alkylation of poly(vinyl acetate) (PVAc) with alkyl iodides. The influence of the alkylating agent and the reaction conditions on the efficiency of the modification reaction was investigated. The copolymers obtained were characterized by means of 1 H NMR and GPC. It was proved that by applying the proposed method copolymers of different composition and properties containing methyl vinyl ether, ethyl vinyl ether as well as n-butyl vinyl ether units could be prepared. Poly(methyl vinyl ether-co-vinyl alcohol)s of high degree of methylation exhibit sharp temperature response at 38-39 deg C in aqueous solution typical of the so-called smart polymers. (authors)

Synthesis and Properties of the Metallo-Supramolecular Polymer Hydrogel Poly[methyl vinyl ether-alt-mono-sodium maleate]∙AgNO3

KAUST Repository

Al-Dossary, Mona S.

2014-05-01

Gels are a special class of materials which are composed of 3D networks of crosslinked polymer chains that encapsulate liquid/air in the matrix. They can be classified into organogels or hydrogels (organic solvent for organogel and water for hydrogel). For hydrogels that contain metallic elements in the form of ions, the term of metallo-supramolecular polymer hydrogel (MSPHG) is often used. The aim of this project is to develop a kind of new MSPHG and investigate its properties and possible applications. The commercial polymeric anhydride poly(methyl vinyl ether-alt-maleic anhydride) (PVM/MA) is converted by reaction with NaOH to give poly(methyl vinyl ether-alt-monosodium maleate) (PVM/Na-MA). By addition of AgNO3-solution, the formation of the silver(I) supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]∙AgNO3 is obtained. Freeze-dried samples of the hydrogel show a mesoporous network of polycarboxylate ligands that are crosslinked by silver(I) cations. The supercritical CO2 dried silver(I) hydrogel was characterized by FT-IR, SEM-EDAX, TEM, TGA and Physical adsorption (BET) measurements. The intact silver(I) hydrogel was characterized by cryo-SEM. In the intact hydrogel, ion-exchange studies are reported and it is shown that Ag+ ions can be exchanged by copper(II) cations without disintegration of the hydrogel. The silver(I) hydrogel shows effective antibacterial activity and potential application as burn wound dressing.

Anion exchange membranes based on terminally crosslinked methyl morpholinium-functionalized poly(arylene ether sulfone)s

Science.gov (United States)

Kwon, Sohyun; Rao, Anil H. N.; Kim, Tae-Hyun

2018-01-01

Azide-assisted terminal crosslinking of methyl morpholinium-functionalized poly(arylene ether sulfone) block copolymers yields products (xMM-PESs) suitable for use as anion exchange membranes. By combining the advantages of bulky morpholinium conductors and our unique polymer network crosslinked only at the termini of the polymer chains, we can produce AEMs that after the crosslinking show minimal loss in conductivity, yet with dramatically reduced water uptake. Terminal crosslinking also significantly increases the thermal, mechanical and chemical stability levels of the membranes. A high ion conductivity of 73.4 mS cm-1 and low water uptake of 26.1% at 80 °C are obtained for the crosslinked membrane with higher amount of hydrophilic composition, denoted as xMM-PES-1.5-1. In addition, the conductivity of the crosslinked xMM-PES-1.5-1 membrane exceeds that of its non-crosslinked counterpart (denoted as MM-PES-1.5-1) above 60 °C at 95% relative humidity because of its enhanced water retention capacity caused by the terminally-crosslinked structure.

Lewis Acid Assisted Nickel-Catalyzed Cross-Coupling of Aryl Methyl Ethers by C−O Bond-Cleaving Alkylation: Prevention of Undesired β-Hydride Elimination

KAUST Repository

Liu, Xiangqian; Hsiao, Chien-Chi; Kalvet, Indrek; Leiendecker, Matthias; Guo, Lin; Schoenebeck, Franziska; Rueping, Magnus

2016-01-01

In the presence of trialkylaluminum reagents, diverse aryl methyl ethers can be transformed into valuable products by C-O bond-cleaving alkylation, for the first time without the limiting β-hydride elimination. This new nickel

Preparation of H3-labelled methyl ethers of saturated fatty acids by heterogeneous catalytic isotope exchange in solution with gaseous tritium

International Nuclear Information System (INIS)

Shevchenko, V.P.; Myasoedov, N.F.

1980-01-01

A simple method of preparing 3 H-labelled methyl ethers of saturated fatty acids in the dioxane solution using the method of isotopic heterogenous catalytic exchange with gaseous tritium, is suggested. 3 H-labelled natural fatty acids (C 12 -C 18 ) are prepared by alkaline hydrolysis [ru

Modeling of a Reaction-Distillation-Recycle System to Produce Dimethyl Ether through Methanol Dehydration

Science.gov (United States)

Muharam, Y.; Zulkarnain, L. M.; Wirya, A. S.

2018-03-01

The increase in the dimethyl ether yield through methanol dehydration due to a recycle integration to a reaction-distillation system was studied in this research. A one-dimensional phenomenological model of a methanol dehydration reactor and a shortcut model of distillation columns were used to achieve the aim. Simulation results show that 10.7 moles/s of dimethyl ether is produced in a reaction-distillation system with the reactor length being 4 m, the reactor inlet pressure being 18 atm, the reactor inlet temperature being 533 K, the reactor inlet velocity being 0.408 m/s, and the distillation pressure being 8 atm. The methanol conversion is 90% and the dimethyl ether yield is 48%. The integration of the recycle stream to the system increases the dimethyl ether yield by 8%.

Poly(Poly(Ethylene Glycol Methyl Ether Methacrylate Grafted Chitosan for Dye Removal from Water

Directory of Open Access Journals (Sweden)

Bryan Tsai

2017-03-01

Full Text Available As the demand for textile products and synthetic dyes increases with the growing global population, textile dye wastewater is becoming one of the most significant water pollution contributors. Azo dyes represent 70% of dyes used worldwide, and are hence a significant contributor to textile waste. In this work, the removal of a reactive azo dye (Reactive Orange 16 from water by adsorption with chitosan grafted poly(poly(ethylene glycol methyl ether methacrylate (CTS-GMA-g-PPEGMA was investigated. The chitosan (CTS was first functionalized with glycidyl methacrylate and then grafted with poly(poly(ethylene glycol methyl ether methacrylate using a nitroxide-mediated polymerization grafting to approach. Equilibrium adsorption experiments were carried out at different initial dye concentrations and were successfully fitted to the Langmuir and Freundlich adsorption isotherm models. Adsorption isotherms showed maximum adsorption capacities of CTS-g-GMA-PPEGMA and chitosan of 200 mg/g and 150 mg/g, respectively, while the Langmuir equations estimated 232 mg/g and 194 mg/g, respectively. The fundamental assumptions underlying the Langmuir model may not be applicable for azo dye adsorption, which could explain the difference. The Freundlich isotherm parameters, n and K, were determined to be 2.18 and 17.7 for CTS-g-GMA-PPEGMA and 0.14 and 2.11 for chitosan, respectively. An “n” value between one and ten generally indicates favorable adsorption. The adsorption capacities of a chitosan-PPEGMA 50/50 physical mixture and pure PPEGMA were also investigated, and both exhibited significantly lower adsorption capacities than pure chitosan. In this work, CTS-g-GMA-PPEGMA proved to be more effective than its parent chitosan, with a 33% increase in adsorption capacity.

On the some reactions of mixed ethers of phosphorus acid with acrylonitrile and methyl iodide

International Nuclear Information System (INIS)

Gusev, Yu.K.; Chistokletov, V.N.; Petrov, A.A.

1977-01-01

The bimolecular mechanism has been confirmed of the redgrouping stage of Arbuzov's classical reactions for phosphites containing primary and secondary radicals in reactions of acrylonitrile and methyl iodide with some mixed ethers of phosphoric acid. It is suggested that dealcylation of the intermediate products formed on interaction of olefins activated by electron-acceptor groups with phosphites containing primary radicals occurs according to the Ssub(N)2-mechanism, secondary radicals, according to the mixed Ssub(N)2 and Ssub(N)1-mechanism,and radicals capable of forming stable carbonium ions, according to the Ssub(N)1-mechanism

Effect of trimethylcolchicinic acid methyl ether d-tartrate (TMCA) on Hodgkin's and non-Hodgkin's lymphoma.

Science.gov (United States)

Stolinsky, D C; Jacobs, E M; Irwin, L E; Pajak, T F; Bateman, J R

1976-01-01

Trimethylcolchicinic acid methyl ether d-tartrate (TMCA; NSC-36351) was administered daily by mouth to 71 patients with malignant lymphomas. Partical (greater than 50%) responses were observed in eleven of 37 patients with Hodgkin's disesse, two of 22 patients with lymphocytic lymphoma, and one of two patients with mixed cell lymphoma. One complete and three partial responses were noted in nine patients with histiocytic lymphoma. Responses lasted from one to 91+ months (median: four months) and occurred in patients whose disease was resistant to alkylating agents, vinblastine, vincristine, procarbazine, prednisone or BCNU. Toxic effects included leukopenia, thrombocytopenia, nausea, diarrhea, stomatitis, alopecia and dermatitis.

Poly(vinyl methyl ether/maleic anhydride)-Doped PEG-PLA Nanoparticles for Oral Paclitaxel Delivery To Improve Bioadhesive Efficiency.

Science.gov (United States)

Wang, Qian; Li, Chan; Ren, Tianyang; Chen, Shizhu; Ye, Xiaoxia; Guo, Hongbo; He, Haibing; Zhang, Yu; Yin, Tian; Liang, Xing-Jie; Tang, Xing

2017-10-02

Bioadhesive nanoparticles based on poly(vinyl methyl ether/maleic anhydride) (PVMMA) and poly(ethylene glycol) methyl ether-b-poly(d,l-lactic acid) (mPEG-b-PLA) were produced by the emulsification solvent evaporation method. Paclitaxel was utilized as the model drug, with an encapsulation efficiency of up to 90.2 ± 4.0%. The nanoparticles were uniform and spherical in shape and exhibited a sustained drug release compared with Taxol. m-NPs also exhibited favorable bioadhesive efficiency at the same time. Coumarin 6 or DiR-loaded nanoparticles with/without PVMMA (C6-m-NPs/DiR-m-NPs or C6-p-NPs/DiR-p-NPs) were used for cellular uptake and intestinal adhesion experiments, respectively. C6-m-NPs were shown to enhance cellular uptake, and caveolae/lipid raft mediated endocytosis was the primary route for the uptake of the nanoparticles. Favorable bioadhesive efficiency led to prolonged retention in the intestine reflected by the fluorescence in isolated intestines ex vivo. In a ligated intestinal loops model, C6-m-NPs showed a clear advantage for transporting NPs across the mucus layer over C6-p-NPs and free C6. The apparent permeability coefficient (Papp) of PTX-m-NPs through Caco-2/HT29 monolayers was 1.3- and 1.6-fold higher than PTX-p-NPs and Taxol, respectively, which was consistent with the AUC 0-t of different PTX formulations after oral administration in rats. PTX-m-NPs also exhibited a more effective anticancer efficacy, with an IC 50 of 0.2 ± 1.4 μg/mL for A549 cell lines, further demonstrating the advantage of bioadhesive nanoparticles. The bioadhesive nanoparticles m-NPs demonstrated both mucus permeation and epithelial absorption, and thus, this bioadhesive drug delivery system has the potential to improve the bioavailability of drugs that are insoluble in the gastrointestinal environment.

Radiation chemistry of alternative fuel oxygenates - substituted ethers

International Nuclear Information System (INIS)

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

1999-01-01

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)

Detection and Quantification of Methyl tert-Butyl Ether-Degrading Strain PM1 by Real-Time TaqMan PCR

OpenAIRE

Hristova, Krassimira R.; Lutenegger, Christian M.; Scow, Kate M.

2001-01-01

The fuel oxygenate methyl tert-butyl ether (MTBE), a widely distributed groundwater contaminant, shows potential for treatment by in situ bioremediation. The bacterial strain PM1 rapidly mineralizes and grows on MTBE in laboratory cultures and can degrade the contaminant when inoculated into groundwater or soil microcosms. We applied the TaqMan quantitative PCR method to detect and quantify strain PM1 in laboratory and field samples. Specific primers and probes were designed for the 16S ribos...

Fatty acid methyl esters synthesis from non-edible vegetable oils using supercritical methanol and methyl tert-butyl ether

International Nuclear Information System (INIS)

Lamba, Neha; Modak, Jayant M.; Madras, Giridhar

2017-01-01

Highlights: • FAMEs were synthesized from non-edible oils using supercritical MeOH and MTBE. • Effect of time, temperature, pressure and molar ratio on conversions was studied. • Rate constants of reaction with methanol and MTBE differ by an order of magnitude. • Non-catalytic supercritical reactions are one order faster than acid catalyzed synthesis. - Abstract: Fatty acid methyl esters (FAMEs) are useful as biodiesel and have environmental benefits compared to conventional diesel. In this study, these esters were synthesized non-catalytically from non-edible vegetable oils: neem oil and mahua oil with two different methylating agents: methanol and methyl tert-butyl ether (MTBE). The effects of temperature, pressure, time and molar ratio on the conversion of triglycerides were studied. The temperature was varied in the range of 523–723 K with molar ratios upto 50:1 and a reaction time of upto 150 min. Conversion of neem and mahua oil to FAMEs with supercritical methanol was found to be 83% in 15 min and 99% in 10 min, respectively at 698 K. Further, a conversion of 46% of mahua oil and 59% of neem oil was obtained in 15 min at 723 K using supercritical MTBE. The rate constants evaluated using pseudo first order reaction kinetics were in the range of 4.7 × 10"−"6 to 1.0 × 10"−"3 s"−"1 for the investigated range of temperatures. The activation energies obtained were in the range of 62–113 kJ/mol for the reaction systems investigated. The supercritical synthesis was found to be superior to the catalytic synthesis of the corresponding FAMEs.

Thermodynamic and kinetic analysis of phase separation of temperature-sensitive poly(vinyl methyl ether) in the presence of hydrophobic tert-butyl alcohol

Czech Academy of Sciences Publication Activity Database

Velychkivska, Nadiia; Bogomolova, Anna; Filippov, Sergey K.; Starovoytova, Larisa; Labuta, J.

2017-01-01

Roč. 295, č. 8 (2017), s. 1419-1428 ISSN 0303-402X R&D Projects: GA ČR(CZ) GC15-10527J Institutional support: RVO:61389013 Keywords : phase separation * coil-globule transition * poly(vinyl methyl ether) Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.723, year: 2016

Synthesis of [11C]-labelled methyl esters: transesterification of enol esters versus BF3 etherate catalysed esterification - a comparative study

International Nuclear Information System (INIS)

Ackermann, U.; Falzon, C.; Issa, W.; Tochon-Danguy, H.J.; Sachinidis, J.I.; Blanc, P.; White, J.; Scott, A.M.

2005-01-01

An important issue in Positron Emission Tomography (PET) is the development of labelling techniques to incorporate positron emitting radionuclides into biologically active compounds. When labelling with 11C, the short 20 minutes half-life of the radionuclide significantly limits the number of synthetic protocols available to the radiochemist. C-l synthons such as [HCJ-methyl iodide (1) or methyl triflate (2) are readily available and are frequently used as alkylating agents for the preparation of radiopharmaceuticals. However, the use of these alkylating agents often makes it necessary to introduce protecting groups in order to prevent labelling at unwanted sites on the molecule. Since the removal of protecting groups is a time-consuming process, a more direct synthesis strategy is desirable. This has prompted us to investigate the esterification of carboxylic acids using [1 lC]-mcthanol and BF3 etherate as Lewis acid catalyst. Our results have demonstrated that the reaction conditions necessary to promote the esterification can cleave functional groups such as ethers. We have therefore shifted our attention towards the irreversible transesterification of enol esters using [HCl-methanol and a tin catalyst as an alternative strategy to [HC]-methyl ester formation. We have prepared a series of 5 aromatic ethoxy vinyl esters bearing various functional groups. The transesterification (radiolabelling) was carried out in DMSO at 150 Degrees C for 7 minutes in the presence of [HQMeOH and 1.3-dichlo-rotetrabutyldistannoxane as catalyst. We have found that the transesterification of enol esters is a mild and efficient labelling method for the formation of [HCl-methyl esters. The reaction proceeds smoothly and leaves functional groups intact. It requires only one synthesis step compared to two steps for the conventional method, and gives a radiochemical yields of 25%

Identification of a polyketide synthase required for alternariol (AOH and alternariol-9-methyl ether (AME formation in Alternaria alternata.

Directory of Open Access Journals (Sweden)

Debjani Saha

Full Text Available Alternaria alternata produces more than 60 secondary metabolites, among which alternariol (AOH and alternariol-9-methyl ether (AME are important mycotoxins. Whereas the toxicology of these two polyketide-based compounds has been studied, nothing is known about the genetics of their biosynthesis. One of the postulated core enzymes in the biosynthesis of AOH and AME is polyketide synthase (PKS. In a draft genome sequence of A. alternata we identified 10 putative PKS-encoding genes. The timing of the expression of two PKS genes, pksJ and pksH, correlated with the production of AOH and AME. The PksJ and PksH proteins are predicted to be 2222 and 2821 amino acids in length, respectively. They are both iterative type I reducing polyketide synthases. PksJ harbors a peroxisomal targeting sequence at the C-terminus, suggesting that the biosynthesis occurs at least partly in these organelles. In the vicinity of pksJ we found a transcriptional regulator, altR, involved in pksJ induction and a putative methyl transferase, possibly responsible for AME formation. Downregulation of pksJ and altR caused a large decrease of alternariol formation, suggesting that PksJ is the polyketide synthase required for the postulated Claisen condensations during the biosynthesis. No other enzymes appeared to be required. PksH downregulation affected pksJ expression and thus caused an indirect effect on AOH production.

Chronic Carcinogenicity Study of Gasoline Vapor Condensate (GVC) and GVC Containing Methyl Tertiary-Butyl Ether in F344 Rats

OpenAIRE

Benson, Janet M.; Gigliotti, Andrew P.; March, Thomas H.; Barr, Edward B.; Tibbetts, Brad M.; Skipper, Betty J.; Clark, Charles R.; Twerdok, Lorraine

2011-01-01

Chronic inhalation studies were conducted to compare the toxicity and potential carcinogenicity of evaporative emissions from unleaded gasoline (GVC) and gasoline containing the oxygenate methyl tertiary-butyl ether (MTBE; GMVC). The test materials were manufactured to mimic vapors people would be exposed to during refueling at gas stations. Fifty F344 rats per gender per exposure level per test article were exposed 6 h/d, 5 d/wk for 104 wk in whole body chambers. Target total vapor concentra...

NMR study of temperature-induced phase separation and polymer-solvent interactions in poly(vinyl methyl ether)/D.sub.2./sub.O/ethanol solutions

Czech Academy of Sciences Publication Activity Database

Hanyková, L.; Labuta, J.; Spěváček, Jiří

2006-01-01

Roč. 47, č. 17 (2006), s. 6107-6116 ISSN 0032-3861 Grant - others:GA UK 294/2004/B Institutional research plan: CEZ:AV0Z40500505 Keywords : poly(vinyl methyl ether)/D2O/ ethanol solutions * temperature-induced phase separation * 1H and 13C NMR spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.773, year: 2006

The polymerisation of oligo(ethylene glycol methyl ether) methacrylate from a multifunctional poly(ethylene imine) derived amide : a stabiliser for the synthesis and dispersion of magnetite nanoparticles

NARCIS (Netherlands)

Kleine, A.; Altan, C.L.; Yarar, U.E.; Sommerdijk, N.A.J.M.; Bucak, S.; Holder, S.J.

2014-01-01

A facile synthetic route to poly(ethylene imine)-graft-poly(oligo(ethylene glycol methyl ether)) (PEI-graft-POEGMA) functionalised superparamagnetic magnetite nanoparticles is described. The polymerisation of OEGMA from a model molecular amide demonstrated the feasibility of POEGMA synthesis under

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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.

Vapour pressures for 1-(butoxymethoxy)butane (dibutoxymethane) and 1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxybutane (methyl nonafluorobutyl ether) over the pressure range of (15–80) kPa

International Nuclear Information System (INIS)

Gárate, María P.; Bejarano, Arturo; Fuente, Juan C. de la

2016-01-01

Highlights: • Vapour pressures of two pure potential dry-cleaning solvent were measured. • Measurements were made over the temperature range of (294.6–442.7) K. • Three commonly used vapour pressure equations were fitted to the experimental data. • The parameters of Antoine and Wagner type equations were estimated. • The relative deviations (rmsd) from the three vapour-pressure equations were <0.6%. - Abstract: Saturated pressures of 1-(butoxymethoxy)butane (dibutoxymethane) and 1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxybutane (methyl nonafluorobutyl ether), new potential solvents for dry-cleaning processes, were measured with a dynamic recirculation apparatus at a pressure range of (15–80) kPa, at temperatures of (390.4–442.7) K for dibutoxymethane and (294.6–322.4) K for methyl nonafluorobutyl ether. The vapour pressures were represented using the correlations of Antoine, extended Antoine and Wagner with relative root mean square deviations of, 1%, 6% and 0.6% for dibutoxymethane, and, 1%, 2% and 0.6% for methyl nonafluorobutyl ether, respectively. The experimental data of dibutoxymethane was compared with those available in literature, the result showed consistency between both data sets.

An efficient and highly selective ortho-tert-butylation of p-cresol with methyl tert-butyl ether catalyzed by sulfonated ionic liquids

Directory of Open Access Journals (Sweden)

Alamdari Reza Fareghi

2014-01-01

Full Text Available A novel series of sulfonic acid-functionalized ionic liquids (SFILs was found to act as efficient catalysts for ortho-tert-butylation of p-cresol with methyl tert-butyl ether (MTBE as the tert-butylating agent without an added solvent. The mono o-tert-butylated product was obtained in up to 80.4% isolated yield and 95.2% selectivity under such green conditions. No O-tert-butylated byproducts were formed.

New biphasic solvent system based on cyclopentyl methyl ether for the purification of a non-polar synthetic peptide by pH-zone refining centrifugal partition chromatography.

Science.gov (United States)

Amarouche, Nassima; Boudesocque, Leslie; Borie, Nicolas; Giraud, Matthieu; Forni, Luciano; Butte, Alessandro; Edwards, Florence; Renault, Jean-Hugues

2014-06-01

A new type 1 ternary biphasic system composed of cyclopentyl methyl ether, dimethylformamide and water was developed, characterized and successfully used for the purification of a lipophilic, protected peptide by pH-zone refining centrifugal partition chromatography. The protected peptide is an 8-mer, key intermediate in bivalirudin (Angiomax®) synthesis and shows a very low solubility in the solvents usually used in liquid chromatography. All ionic groups, except the N-terminal end of the peptide, are protected by a benzyl group. The purification of this peptide was achieved with a purity of about 99.04% and a recovery of 94% using the new ternary biphasic system cyclopentyl methyl ether/dimethylformamide/water (49:40:11, v/v) in the descending pH-zone refining mode with triethylamine (28 mM) as the retainer and methanesulfonic acid (18 mM) as the eluter. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

UV-A photooxidation of β-carotene in Triton X-100 micelles by nitrodiphenyl ether herbicides

International Nuclear Information System (INIS)

Orr, G.L.; Hogan, M.E.

1985-01-01

Photooxidation of β-carotene in Triton X-100 micelles was stimulated by lipophilic nitrodiphenyl ether herbicides at concentrations as low as 5 μM after 15 min in UV radiation (UV-A between 315 and 400 nm). Bleaching of β-carotene by acifluorfen-methyl [methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate] was proportional to UV-A intensity and independent of pH. White light (400-700 nm) alone was without effect. At pH 6.5, 100 μM acifluorfen [sodium 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate], a water-soluble nitrodiphenyl ether, stimulated photooxidation of β-carotene after 15 min in UV-A radiation. Activity of 200 μM acifluorfen was enhanced at pHs between 3.5 and 6.5. The chlorodiphenyl ether analogue of acifluorfen-methyl, methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-chlorobenzoate, exhibited little activity at 200 μM and 200 μM phenyl ether was without effect. Activation energy for acifluorfen-methyl stimulated β-carotene photooxidation near 20 and 30 0 C was 40.3 and 5.6 kJ mol -1 , respectively. Subsequent to UV-A exposure and placement into darkness no further bleaching of β-carotene was detected, indicating that reactive species were generated only in light and consumed quickly in darkness

Anaerobic degradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA).

Science.gov (United States)

Finneran, K T; Lovley, D R

2001-05-01

The potential for anaerobic degradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) was investigated in laboratory incubations of sediments from a petroleum-contaminated aquifer and in aquatic sediments. The addition of humic substances (HS) stimulated the anaerobic degradation of MTBE in aquifer sediments in which Fe(III) was available as an electron acceptor. This is attributed to the fact that HS and other extracellular quinones can stimulate the activity of Fe(III)-reducing microorganisms by acting as an electron shuttle between Fe(III)-reducing microorganisms and insoluble Fe(III) oxides. MTBE was not degraded in aquifer sediments without Fe(III) and HS. [14C]-MTBE added to aquatic sediments adapted for anaerobic MTBE degradation was converted to 14CO2 in the presence or absence of HS or the HS analog, anthraquione-2,6-disulfonate. Unamended aquatic sediments produced 14CH4 as well as 14CO2 from [14C]-MTBE. The aquatic sediments also rapidly consumed TBA under anaerobic conditions and converted [14C]-TBA to 14CH4 and 14CO2. An adaptation period of ca. 250-300 days was required prior to the most rapid anaerobic MTBE degradation in both sediment types, whereas TBA was metabolized in the aquatic sediments without a lag. These results demonstrate that, under the appropriate conditions, MTBE and TBA can be degraded in the absence of oxygen. This suggests that it may be possible to design strategies for the anaerobic remediation of MTBE in petroleum-contaminated subsurface environments.

IRON(III) NITRATE-CATALYZED FACILE SYNTHESIS OF DIPHENYLMETHYL (DPM) ETHERS FROM ALCOHOLS

Science.gov (United States)

Diphenyl methyl (DPM) ethers constitute important structural portion of some pharmaceutical entities and also as protective group for hydroxyl groups in synthetic chemistry. DPM ethers are normally prepared using concentrated acids or base as catalysts, which may result in the fo...

Blood pharmacokinetics of tertiary amyl methyl ether in male and female F344 rats and CD-1 mice after nose-only inhalation exposure.

Science.gov (United States)

Sumner, Susan C J; Janszen, Derek B; Asgharian, Bahman; Moore, Timothy A; Bobbitt, Carol M; Fennell, Timothy R

2003-01-01

Interest in understanding the biological behavior of aliphatic ethers has increased owing to their use as gasoline additives. The purpose of this study was to investigate the blood pharmacokinetics of the oxygenate tertiary amyl methyl ether (TAME), its major metabolite tertiary amyl alcohol (TAA) and acetone in rats and mice following inhalation exposure to TAME. Species differences in the area under the curve (AUC) for TAME were significant at each exposure concentration. For rats, the blood TAME AUC increased in proportion with an increase in exposure concentration. For mice, an increase in exposure concentration (100-500 ppm) resulted in a disproportional increase in the TAME AUC. Mice had greater (two- to threefold) blood concentrations of TAA compared with rats following exposure to 2500 or 500 ppm TAME. Mice had a disproportional increase in the TAA AUC with an increase in exposure concentration (100-500 ppm). This difference could result from saturation of a process (e.g. oxidation, glucuronide conjugation) that is involved in the further metabolism of TAA. For each species, gender and exposure concentration, acetone increased during exposure and returned to control values by 16 h following exposure. The source of acetone could be both as a metabolite of TAA or an effect on endogenous metabolism produced by exposure to TAME. Copyright 2003 John Wiley & Sons, Ltd.

Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

Energy Technology Data Exchange (ETDEWEB)

Francois, A

2002-11-01

Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

On the predictive capabilities of CPA for applications in the chemical industry: Mulficomponent mixtures containing methyl-methacrylate, dimethyl-ether or acetic acid

DEFF Research Database (Denmark)

Tsivintzelis, Ioannis; Kontogeorgis, Georgios

2014-01-01

mixtures exhibiting vapor-liquid (VLE) and/or liquid-liquid (LLE) equilibrium. The first two cases include mixtures of methyl-methacrylate with acetone or methanol and dimethyl-ether with ethanol, respectively. In these two cases, the classical form of CPA is used. The third case involves aqueous mixtures...... for the acetic acid-water system for which different parameter sets at different temperatures can be recommended. Even with the use of CPA-HV mixing rules, modeling of the acetic acid-water system with few interaction parameters remains a challenging task. Excellent simultaneous VLE and LLE correlation...... is obtained for complex systems such as aqueous mixtures with ethers and esters. The multicomponent results are, with a few exceptions, very satisfactory, especially for the vapor-liquid equilibrium cases. For the demanding aqueous acetic acid-water containing systems, one parameter set is recommended...

The fungal phytotoxin alternariol 9-methyl ether and some of its synthetic analogues inhibit the photosynthetic electron transport chain.

Science.gov (United States)

Demuner, Antonio Jacinto; Barbosa, Luiz Cláudio Almeida; Miranda, Ana Cristina Mendes; Geraldo, Guilherme Carvalho; da Silva, Cleiton Moreira; Giberti, Samuele; Bertazzini, Michele; Forlani, Giuseppe

2013-12-27

Alternariol and monomethylalternariol are natural phytotoxins produced by some fungal strains, such as Nimbya and Alternaria. These substances confer virulence to phytopathogens, yet no information is available concerning their mode of action. Here we show that in the micromolar range alternariol 9-methyl ether is able to inhibit the electron transport chain (IC50 = 29.1 ± 6.5 μM) in isolated spinach chloroplasts. Since its effectiveness is limited by poor solubility in water, several alternariol analogues were synthesized using different aromatic aldehydes. The synthesized 6H-benzo[c]cromen-6-ones, 5H-chromene[4,3-b]pyridin-5-one, and 5H-chromene[4,3-c]pyridin-5-one also showed inhibitory properties, and three 6H-benzo[c]cromen-6-ones were more effective (IC50 = 12.8-22.8 μM) than the lead compound. Their addition to the culture medium of a cyanobacterial model strain was found to inhibit algal growth, with a relative effectiveness that was consistent with their activity in vitro. In contrast, the growth of a nonphotosynthetic plant cell culture was poorly affected. These compounds may represent a novel lead for the development of new active principles targeting photosynthesis.

rett produc Congo ted cas ced in to: Nsam ssava two tra m

African Journals Online (AJOL)

sunny

2-Nonanone. 1.0451. Linalol GIVAUDAN. 2.4808. CIS-ROSE OXIDE. 0.5274. Ocimene « Neo-allo ». 0.7592. Camphor. 0.5182. 2-Methyl butyl angelate. 0.2858. Menthone. 2.4612. Iso-menthone. 1.1662. Terpinene-4-ol. 1.1721. Methyl salicylate. 0.7165. Estragol. 33.8179. Methyl thymol ether. 0.7945. Methyl carvacrol ether.

Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

Energy Technology Data Exchange (ETDEWEB)

Francois, A.

2002-11-01

Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

Critical properties of some aliphatic symmetrical ethers

International Nuclear Information System (INIS)

Nikitin, Eugene D.; Popov, Alexander P.; Bogatishcheva, Nataliya S.

2014-01-01

Highlights: • Critical properties of simple aliphatic ethers were measured. • The ethers decompose at near-critical temperatures. • Pulse-heating method with short residence times was used. -- Abstract: The critical temperatures T c and the critical pressures p c of dihexyl, dioctyl, and didecyl ethers have been measured. According to the measurements, the coordinates of the critical points are T c = (665 ± 7) K, p c = (1.44 ± 0.04) MPa for dihexyl ether, T c = (723 ± 7) K, p c = (1.19 ± 0.04) MPa for dioctyl ether, and T c = (768 ± 8) K, p c = (1.03 ± 0.03) MPa for didecyl ether. All the ethers studied degrade chemically at near-critical temperatures. A pulse-heating method applicable to measuring the critical properties of thermally unstable compounds has been used. The times from the beginning of a heating pulse to the moment of reaching the critical temperature were from 0.06 to 0.46 ms. The short residence times provide little decomposition of the substances in the course of the experiments. The critical properties of the ethers investigated in this work have been discussed together with those of methyl to butyl ethers. The experimental critical constants of the ethers have been compared with those estimated by the group-contribution methods of Wilson and Jasperson and Marrero and Gani. The Wilson/Jasperson method provides a better estimation of the critical temperatures and pressures of simple aliphatic ethers in comparison with the Marrero/Gani method if reliable normal boiling temperatures are used in the method of Wilson and Jasperson

Polypyrrole-Grafted Coconut Shell Biological Carbon as a Potential Adsorbent for Methyl Tert-Butyl Ether Removal: Characterization and Adsorption Capability

Directory of Open Access Journals (Sweden)

Shanshan Li

2017-01-01

Full Text Available Methyl tert-butyl ether (MTBE has been used as a common gasoline additive worldwide since the late twentieth century, and it has become the most frequently detected groundwater pollutant in many countries. This study aimed to synthesize a novel microbial carrier to improve its adsorptive capacity for MTBE and biofilm formation, compared to the traditional granular activated carbon (GAC. A polypyrrole (PPy-modified GAC composite (PPy/GAC was synthesized, and characterized by Fourier transform infrared spectroscopy (FT-IR and Brunauer-Emmett-Teller (BET surface area analysis. The adsorption behaviors of MTBE were well described by the pseudo-second-order and Langmuir isotherm models. Furthermore, three biofilm reactors were established with PPy/GAC, PPy, and GAC as the carriers, respectively, and the degradation of MTBE under continuous flow was investigated. Compared to the biofilm reactors with PPy or GAC (which both broke after a period of operation, the PPy/GAC biofilm column produced stable effluents under variable treatment conditions with a long-term effluent MTBE concentration <20 μg/L. Pseudomonas aeruginosa and Acinetobacter pittii may be the predominant bacteria responsible for MTBE degradation in these biofilm reactors.

Convenient procedures for the α-metallation of vinylic ethers and thioethers

NARCIS (Netherlands)

Verkruijsse, H.D.; Brandsma, L.; Schleyer, P. von R.

1987-01-01

Ethyl vinyl ether H2C=CHOC2H5 and the analogous cyclic vinylic ethers dehydrofuran and 2,3-dihydropyran can be potassiated at −20°C in the α-position with a 1/1/1 molar mixture of BuLi, t-BuOK and TMEDA in hexane. Methyl vinyl sulfide is potassiated very smoothly by a 1/1 molar mixture of BuLi and

Lewis Acid Assisted Nickel-Catalyzed Cross-Coupling of Aryl Methyl Ethers by C−O Bond-Cleaving Alkylation: Prevention of Undesired β-Hydride Elimination

KAUST Repository

Liu, Xiangqian

2016-04-10

In the presence of trialkylaluminum reagents, diverse aryl methyl ethers can be transformed into valuable products by C-O bond-cleaving alkylation, for the first time without the limiting β-hydride elimination. This new nickel-catalyzed dealkoxylative alkylation method enables powerful orthogonal synthetic strategies for the transformation of a variety of naturally occurring and easily accessible anisole derivatives. The directing and/or activating properties of aromatic methoxy groups are utilized first, before they are replaced by alkyl chains in a subsequent coupling process.

Carcinogenicity of methyl-tertiary butyl ether in gasoline.

Science.gov (United States)

Mehlman, Myron A

2002-12-01

Methyl tertiary butyl ether (MTBE) was added to gasoline on a nationwide scale in 1992 without prior testing of adverse, toxic, or carcinogenic effects. Since that time, numerous reports have appeared describing adverse health effects of individuals exposed to MTBE, both from inhalation of fumes in the workplace and while pumping gasoline. Leakage of MTBE, a highly water-soluble compound, from underground storage tanks has led to contamination of the water supply in many areas of the United States. Legislation has been passed by many states to prohibit the addition of MTBE to gasoline. The addition of MTBE to gasoline has not accomplished its stated goal of decreasing air pollution, and it has posed serious health risks to a large portion of the population, particularly the elderly and those with respiratory problems, asthma, and skin sensitivity. Reports of animal studies of carcinogenicity of MTBE began to appear in the 1990s, prior to the widespread introduction of MTBE into gasoline. These reports were largely ignored. In ensuing years, further studies have shown that MTBE causes various types of malignant tumors in mice and rats. The National Toxicology Program (NTP) Board of Scientific Counselors' Report on Carcinogens Subcommittee met in December 1998 to consider listing MTBE as "reasonably anticipated to be a human carcinogen." In spite of recommendations from Dr. Bailer, the primary reviewer, and other scientists on the committee, the motion to list MTBE in the report was defeated by a six to five vote, with one abstention. On the basis of animal studies, it is widely accepted that if a chemical is carcinogenic in appropriate laboratory animal test systems, it must be treated as though it were carcinogenic in humans. In the face of compelling evidence, NTP Committee members who voted not to list MTBE as "reasonably anticipated to be a human carcinogen" did a disservice to the general public; this action may cause needless exposure of many to health risks

Degradation of methyl tert-butyl ether by gel immobilized Methylibium petroleiphilum PM1.

Science.gov (United States)

Chen, Dongzhi; Chen, Jianmeng; Zhong, Weihong; Cheng, Zhuowei

2008-07-01

Cells of Methylibium petroleiphilum PM1 were immobilized in gel beads to degrade methyl tert-butyl ether (MTBE). Calcium alginate, agar, polyacrylamide and polyvinvyl alcohol were screened as suitable immobilization matrices, with calcium alginate demonstrating the fastest MTBE-degradation rate. The rate was accelerated by 1.8-fold when the beads had been treated in physiological saline for 24h at 28 degrees C. MTBE degradation in mineral salts medium (MSM) was accompanied by the increase of biomass. The half-life of MTBE-degradation activity for the encapsulated cells stored at 28 degrees C was about 120 h, which was obviously longer than that of free cells (approximately 36 h). Efficient reusability of the beads up to 30 batches was achieved in poor nutrition solution as compared to only 6 batches in MSM. The immobilized cells could be operated in a packed-bed reactor for degradation of 10 mg L(-1) MTBE in groundwater with more than 99% removal efficiency at hydraulic retention time of 20 min. These results suggested that immobilized cells of PM1 in bioreactor might be applicable to a groundwater treatment system for the removal of MTBE.

Kinetic Isotope Effects in the Reduction of Methyl Iodide

DEFF Research Database (Denmark)

Holm, Torkil

1999-01-01

a Grignard reagent to methyl iodide, and for reduction of methyl iodide with tributyltin hydride or with gaseous hydrogen iodide. Very small KIE's were found for electron transfer to methyl iodide from magnesium in ether or from sodium in ammonia. The reason may be that these reactions are transport...

Pulse radiolysis study of reactions of alkyl and alkylperoxy radicals originating from methyl tert-butyl ether in the gas phase

DEFF Research Database (Denmark)

Langer, S.; Ljungström, E.; Ellermann, T.

1995-01-01

UV spectra and kinetics for the reactions of alkyl and alkylperoxy radicals from methyl tert-butyl ether (MTBE) were studied in 1 atm of SF6 by the pulse radiolysis-UV absorption technique. UV spectra for the radical mixtures were quantified from 215 to 340 nm. At 240 nm, sigma(R) = (2.6 +/- 0.4) X...... and the alkylperoxy radicals with NO and NO2 are (9.1 +/- 1.5) X 10(-13), (4.3 +/- 1.6) X 10(-12) and (1.2 +/- 0.3) X 10(-11) cm(3) molecule(-1) s(-1), respectively. The rate constants given above refer to reaction at the tert-butyl side of the molecule....

Synthesis of Fischer carbene complexes of iridium by C-H bond activation of methyl and cyclic ethers: Evidence for reversible {alpha}-hydrogen migration

Energy Technology Data Exchange (ETDEWEB)

Luecke, H.F.; Arndtsen, B.A.; Burger, P.; Bergman, R.G. [Lawrence Berkeley Lab., CA (United States)]|[Univ. of California, Berkeley, CA (United States)

1996-03-13

We report here a mild and versatile route to Fischer carbene complexes of iridium via the activation of C-H bonds of methyl and cyclic ethers, along with our preliminary studies of this rare family of carbene complexes. Theoretical studies suggest that {alpha}-hydrogen migrations can be kinetically favorable if a coordinatively unsaturated species can be accessed. Thus, the lability of the triflate ligand presumably facilitates this process. Further evidence for the rapidity, as well as reversibility, of this rearrangement was obtained by NMR analysis. 20 refs.

21 CFR 172.872 - Methyl ethyl cellulose.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number...

Two-year drinking water carcinogenicity study of methyl tertiary-butyl ether (MTBE) in Wistar rats.

Science.gov (United States)

Dodd, Darol; Willson, Gabrielle; Parkinson, Horace; Bermudez, Edilberto

2013-07-01

Methyl tertiary-butyl ether (MTBE) has been used as a gasoline additive to reduce tailpipe emissions and its use has been discontinued. There remains a concern that drinking water sources have been contaminated with MTBE. A two-year drinking water carcinogenicity study of MTBE was conducted in Wistar rats (males, 0, 0.5, 3, 7.5 mg ml(-1); and females, 0, 0.5, 3, and 15 mg ml(-1)). Body weights were unaffected and water consumption was reduced in MTBE-exposed males and females. Wet weights of male kidneys were increased at the end of two years of exposure to 7.5 mg ml(-1) MTBE. Chronic progressive nephropathy was observed in males and females, was more severe in males, and was exacerbated in the high MTBE exposure groups. Brain was the only tissue with a statistically significant finding of neoplasms. One astrocytoma (1/50) was found in a female rat (15 mg ml(-1)). The incidence of brain astrocytomas in male rats was 1/50, 1/50, 1/50 and 4/50 for the 0, 0.5, 3 and 7.5 mg ml(-1) exposure groups, respectively. This was a marginally significant statistical trend, but not statistically significant when pairwise comparisons were made or when multiple comparisons were taken into account. The incidence of astrocytoma fell within historical control ranges for Wistar rats, and the brain has not been identified as a target organ following chronic administration of MTBE, ethyl tert-butyl ether, or tertiary butyl alcohol (in drinking water) to mice and rats. We conclude that the astrocytomas observed in this study are not associated with exposure to MTBE. Copyright © 2011 John Wiley & Sons, Ltd.

Adverse eff ects of polymeric nanoparticle poly(ethylene glycol- block-polylactide methyl ether (PEG-b-PLA on steroid hormone secretion by porcine granulosa cells

Directory of Open Access Journals (Sweden)

Scsukova Sona

2017-04-01

Full Text Available Objectives. Development of nanoparticles (NPs for biomedical applications, including medical imaging and drug delivery, is currently undergoing a dramatic expansion. Diverse effects of different type NPs relating to mammalian reproductive tissues have been demonstrated. Th e objective of this study was to explore the in vitro effects of polymeric nanoparticle poly(ethylene glycol-blockpolylactide methyl ether (PEG-b-PLA NPs on functional state and viability of ovarian granulosa cells (GCs, which play an important role in maintaining ovarian function and female fertility.

Vapor phase carbonylation of dimethyl ether and methyl acetate with supported transition metal catalysts

International Nuclear Information System (INIS)

Shikada, T.; Fujimoto, K.; Tominaga, H.O.

1986-01-01

The synthesis of acetic acid (AcOH) from methanol (MeOH) and carbon monoxide has been performed industrially in the liquid phase using a rhodium complex catalyst and an iodide promoter. The selectivity to AcOH is more than 99% under mild conditions (175 0 C, 28 atm). The homogeneous rhodium catalyst has been also effective for the synthesis of acetic anhydride (Ac 2 O) by carbonylation of dimethyl ether (DME) or methyl acetate (AcOMe). However, rhodium is one of the most expensive metals and its proved reserves are quite limited. It is highly desired, therefore, to develop a new catalyst as a substitute for rhodium. The authors have already reported that nickel supported on active carbon exhibits an excellent activity for the vapor phase carbonylation of MeOh in the presence of iodide promoter and under moderately pressurized conditions. In addition, corrosive attack on reactors by iodide compounds is expected to be negligible in the vapor phase system. In the present work, vapor phase carbonylation of DME and AcOMe on nickel-active carbon (Ni/A.C.) and molybdenum-active carbon (Mo/A.C.) catalysts was studied

Artificial Neural Network Approach to Predict Biodiesel Production in Supercritical tert-Butyl Methyl Ether

Directory of Open Access Journals (Sweden)

Obie Farobie

2016-05-01

Full Text Available In this study, for the first time artificial neural network was used to predict biodiesel yield in supercritical tert-butyl methyl ether (MTBE. The experimental data of biodiesel yield conducted by varying four input factors (i.e. temperature, pressure, oil-to-MTBE molar ratio, and reaction time were used to elucidate artificial neural network model in order to predict biodiesel yield. The main goal of this study was to assess how accurately this artificial neural network model to predict biodiesel yield conducted under supercritical MTBE condition. The result shows that artificial neural network is a powerful tool for modeling and predicting biodiesel yield conducted under supercritical MTBE condition that was proven by a high value of coefficient of determination (R of 0.9969, 0.9899, and 0.9658 for training, validation, and testing, respectively. Using this approach, the highest biodiesel yield was determined of 0.93 mol/mol (corresponding to the actual biodiesel yield of 0.94 mol/mol that was achieved at 400 °C, under the reactor pressure of 10 MPa, oil-to-MTBE molar ratio of 1:40 within 15 min of reaction time.

Biodegradation of Methyl tert-Butyl Ether by Co-Metabolism with a Pseudomonas sp. Strain

Directory of Open Access Journals (Sweden)

Shanshan Li

2016-09-01

Full Text Available Co-metabolic bioremediation is supposed to be an impressive and promising approach in the elimination technology of methyl tert-butyl ether (MTBE, which was found to be a common pollutant worldwide in the ground or underground water in recent years. In this paper, bacterial strain DZ13 (which can co-metabolically degrade MTBE was isolated and named as Pseudomonas sp. DZ13 based on the result of 16S rRNA gene sequencing analysis. Strain DZ13 could grow on n-alkanes (C5-C8, accompanied with the co-metabolic degradation of MTBE. Diverse n-alkanes with different carbon number showed a significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA. When Pseudomonas sp. DZ13 co-metabolically degraded MTBE with n-pentane as the growth substrate, a higher MTBE-degrading rate (Vmax = 38.1 nmol/min/mgprotein, Ks = 6.8 mmol/L and lower TBA-accumulation was observed. In the continuous degradation experiment, the removal efficiency of MTBE by Pseudomonas sp. Strain DZ13 did not show an obvious decrease after five times of continuous addition.

Oil recovery with sulfomethylated poly (lower alkyl vinyl ether/maleic anhydride)

Energy Technology Data Exchange (ETDEWEB)

Norton, C.J.; Falk, D.O.

1973-05-22

Lower alkyl vinyl ether e.g., methyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether, hexyl vinyl ether, is copolymerized conventionally with maleic anhydride, the resulting copolymer is treated with ammonia or ammonium hydroxide to form the partial amide-ammonium salt, and this salt is in turn treated with formaldehyde and thereafter or simultaneously with ammonium or alkali metal salt sulfite (including bisulfites, etc.) to form an at least partially sulfomethylated copolymer. Aqueous solutions of the sulfomethylated copolymer are useful in increasing the viscosity of drive fluids used in the supplemented recovery of petroleum from subterranean formations. In general, enhancing the polyionic character of mobility control agents used in supplemented recovery of petroleum provides enhanced recovery. Achieving this enhancement of polyionic character through use of sulfonate groups provides a mobility control agent with good ability to sustain viscosity in the presence of brine and lime, usually present in the connate waters of petroleum-bearing formations. (7 claims)

Modeling of the oxidation of methyl esters—Validation for methyl hexanoate, methyl heptanoate, and methyl decanoate in a jet-stirred reactor

Science.gov (United States)

Glaude, Pierre Alexandre; Herbinet, Olivier; Bax, Sarah; Biet, Joffrey; Warth, Valérie; Battin-Leclerc, Frédérique

2013-01-01

The modeling of the oxidation of methyl esters was investigated and the specific chemistry, which is due to the presence of the ester group in this class of molecules, is described. New reactions and rate parameters were defined and included in the software EXGAS for the automatic generation of kinetic mechanisms. Models generated with EXGAS were successfully validated against data from the literature (oxidation of methyl hexanoate and methyl heptanoate in a jet-stirred reactor) and a new set of experimental results for methyl decanoate. The oxidation of this last species was investigated in a jet-stirred reactor at temperatures from 500 to 1100 K, including the negative temperature coefficient region, under stoichiometric conditions, at a pressure of 1.06 bar and for a residence time of 1.5 s: more than 30 reaction products, including olefins, unsaturated esters, and cyclic ethers, were quantified and successfully simulated. Flow rate analysis showed that reactions pathways for the oxidation of methyl esters in the low-temperature range are similar to that of alkanes. PMID:23710076

Modeling of the oxidation of methyl esters-Validation for methyl hexanoate, methyl heptanoate, and methyl decanoate in a jet-stirred reactor.

Science.gov (United States)

Glaude, Pierre Alexandre; Herbinet, Olivier; Bax, Sarah; Biet, Joffrey; Warth, Valérie; Battin-Leclerc, Frédérique

2010-11-01

The modeling of the oxidation of methyl esters was investigated and the specific chemistry, which is due to the presence of the ester group in this class of molecules, is described. New reactions and rate parameters were defined and included in the software EXGAS for the automatic generation of kinetic mechanisms. Models generated with EXGAS were successfully validated against data from the literature (oxidation of methyl hexanoate and methyl heptanoate in a jet-stirred reactor) and a new set of experimental results for methyl decanoate. The oxidation of this last species was investigated in a jet-stirred reactor at temperatures from 500 to 1100 K, including the negative temperature coefficient region, under stoichiometric conditions, at a pressure of 1.06 bar and for a residence time of 1.5 s: more than 30 reaction products, including olefins, unsaturated esters, and cyclic ethers, were quantified and successfully simulated. Flow rate analysis showed that reactions pathways for the oxidation of methyl esters in the low-temperature range are similar to that of alkanes.

Thermochemical biorefinery based on dimethyl ether as intermediate: Technoeconomic assessment

International Nuclear Information System (INIS)

Haro, P.; Ollero, P.; Villanueva Perales, A.L.; Gómez-Barea, A.

2013-01-01

Highlights: ► A thermochemical biorefinery based on bio-DME as intermediate is studied. ► The assessed concepts (12) lead to multi-product generation (polygeneration). ► In all concepts DME is converted by carbonylation or hydrocarbonylation. ► Rates of return are similar to or higher than plants producing a single product. -- Abstract: Thermochemical biorefinery based on dimethyl ether (DME) as an intermediate is studied. DME is converted into methyl acetate, which can either be hydrogenated to ethanol or sold as a co-product. Considering this option together with a variety of technologies for syngas upgrading, 12 different process concepts are analyzed. The considered products are ethanol, methyl acetate, H 2 , DME and electricity. The assessment of each alternative includes biomass pretreatment, gasification, syngas clean-up and conditioning, DME synthesis and conversion, product separation, and heat and power integration. A plant size of 500 MW th processing poplar chips is taken as a basis. The resulting energy efficiency to products ranges from 34.9% to 50.2%. The largest internal rate of return (28.74%) corresponds to a concept which produces methyl acetate, DME and electricity (exported to grid). A sensitivity analysis with respect to total plant investment (TPI), total operation costs (TOC) and market price of products was carried out. The overall conclusion is that, despite its greater complexity, this kind of thermochemical biorefinery is more profitable than thermochemical bioprocesses oriented to a single product.

Diethyl Ether Production Process with Various Catalyst Type

Directory of Open Access Journals (Sweden)

Widayat Widayat

2012-12-01

Full Text Available Several H-zeolite and HZSM-5 catalysts was preparated and their characters have also been investigated. H-zeolit Catalyst was preparated from Natural Zeolite that obtained from Malang District and Gunung Kidul District. Diethyl ether was produced by Ethanol with concentration of 95%. This research use fixed bed reactor that 1 gram of catalyst as bed catalyst, atmospheric pressure and temperature 140oC as the operating condition. Ethanol vapor from vaporization tank was driven by 200 ml/min Nitrogen stream. The responds in this research is liquid product concentration; diethyl ether, ethanol, methanol and water concentration. The results showed that the largest ethanol conversion was produced by the use of 56.44% HZSM-5 and the largest yield of diethyl ether diethyl was produced by the use of alumina and H-zeolite catalyst. The larger ratio between natural zeolite with HCl solvent will produce the larger surface area of catalyst and ethanol conversion. The largest ethanol conversion was produced at reactan ratio 1:20. [Keywords:  catalyst; ethanol conversion; dehydration process; yield of diethyl ether; natural zeolite].

Analysis of electron-irradiated poly-ether ether ketone by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Oyabu, Matashige; Kobayashi, Yoshinori; Seguchi, Tadao; Sasuga, Tsuneo; Kudoh, Hisaaki.

1995-01-01

Organic polymers used in atomic power plants or space are damaged by ionizing irradiation. Radicals produced by irradiation cause oxidation, chain scission and crosslinking, all of which lead to degradation of the material. In this paper, the surface of electron-irradiated poly-ether ether ketone (PEEK) was studied by X-ray photoelectron spectroscopy (XPS). The irradiation in air was found to oxidize the PEEK surface producing carboxyl groups, the content of which dependant on the dose. Carboxyl groups were not produced in helium gas. Quantitative spectral analysis indicated that the aromatic structure might be decomposed. Some comparison was made between the semicrystalline and amorphous samples. The oxygen content resulting from irradiation, of semicrystalline PEEK increased more than that of amorphous PEEK. (author)

Molecular structure impacts on secondary organic aerosol formation from glycol ethers

Science.gov (United States)

Li, Lijie; Cocker, David R.

2018-05-01

Glycol ethers, a class of widely used solvents in consumer products, are often considered exempt as volatile organic compounds based on their vapor pressure or boiling points by regulatory agencies. However, recent studies found that glycol ethers volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents indicating the potential of glycol ethers to form secondary organic aerosol (SOA). This is the first work on SOA formation from glycol ethers. The impact of molecular structure, specifically -OH, on SOA formation from glycol ethers and related ethers are investigated in the work. Ethers with and without -OH, with methyl group hindrance on -OH and with -OH at different location are studied in the presence of NOX and under "NOX free" conditions. Photooxidation experiments under different oxidation conditions confirm that the processing of ethers is a combination of carbonyl formation, cyclization and fragmentation. Bulk SOA chemical composition analysis and oxidation products identified in both gas and particle phase suggests that the presence and location of -OH in the carbon bond of ethers determine the occurrence of cyclization mechanism during ether oxidation. The cyclization is proposed as a critical SOA formation mechanism to prevent the formation of volatile compounds from fragmentation during the oxidation of ethers. Glycol ethers with -CH2-O-CH2CH2OH structure is found to readily form cyclization products, especially with the presence of NOx, which is more relevant to urban atmospheric conditions than without NOx. Glycol ethers are evaluated as dominating SOA precursors among all ethers studied. It is estimated that the contribution of glycol ethers to anthropogenic SOA is roughly 1% of the current organic aerosol from mobile sources. The contribution of glycol ethers to anthropogenic SOA is roughly 1% of the current organic aerosol from mobile sources and will play a more important role in future anthropogenic SOA

Stable carbon and hydrogen isotope analysis of methyl tert-butyl ether and tert-amyl methyl ether by purge and trap-gas chromatography-isotope ratio mass spectrometry: method evaluation and application.

Science.gov (United States)

Kujawinski, Dorothea M; Stephan, Manuel; Jochmann, Maik A; Krajenke, Karen; Haas, Joe; Schmidt, Torsten C

2010-01-01

In order to monitor the behaviour of contaminants in the aqueous environment effective enrichment techniques often have to be employed due to their low concentrations. In this work a robust and sensitive purge and trap-gas chromatography-isotope ratio mass spectrometry method for carbon and hydrogen isotope analysis of fuel oxygenates in water is presented. The method evaluation included the determination of method detection limits, accuracy and reproducibility of deltaD and delta(13)C values. Lowest concentrations at which reliable delta(13)C values could be determined were 5 microg L(-1) and 28 microg L(-1) for TAME and MTBE, respectively. Stable deltaD values for MTBE and TAME could be achieved for concentrations as low as 25 and 50 microg L(-1). Good long-term reproducibility of delta(13)C and deltaD values was obtained for all target compounds. But deltaD values varying more than 5 per thousand were observed using different thermal conversion tubes. Thus, a correction of deltaD values in the analysis of groundwater samples was necessary to guarantee comparability of the results. The applicability of this method was shown by the analysis of groundwater samples from a gasoline contaminated site. By two dimensional isotope analysis two locations within this site were identified at which anaerobic and aerobic degradation of methyl tert-butyl ether occurred.

Temperature-Induced Desorption of Methyl tert-Butyl Ether Confined on ZSM-5: An In Situ Synchrotron XRD Powder Diffraction Study

Directory of Open Access Journals (Sweden)

Elisa Rodeghero

2017-02-01

Full Text Available The temperature-induced desorption of methyl tert-butyl ether (MTBE from aqueous solutions onto hydrophobic ZSM-5 was studied by in situ synchrotron powder diffraction and chromatographic techniques. This kind of information is crucial for designing and optimizing the regeneration treatment of such zeolite. The evolution of the structural features monitored by full profile Rietveld refinements revealed that a monoclinic (P21/n to orthorhombic (Pnma phase transition occurred at about 100 °C. The MTBE desorption process caused a remarkable change in the unit-cell parameters. Complete MTBE desorption was achieved upon heating at about 250 °C. Rietveld analysis demonstrated that the desorption process occurred without any significant zeolite crystallinity loss, but with slight deformations in the channel apertures.

Poly(methyl vinyl ether-alt-maleic acid)-functionalized porous silicon nanoparticles for enhanced stability and cellular internalization.

Science.gov (United States)

Shahbazi, Mohammad-Ali; Almeida, Patrick V; Mäkilä, Ermei; Correia, Alexandra; Ferreira, Mónica P A; Kaasalainen, Martti; Salonen, Jarno; Hirvonen, Jouni; Santos, Hélder A

2014-03-01

Currently, developing a stable nanocarrier with high cellular internalization and low toxicity is a key bottleneck in nanomedicine. Here, we have developed a successful method to covalently conjugate poly(methyl vinyl ether-co-maleic acid) (PMVE-MA) copolymer on the surface of (3-aminopropyl)triethoxysilane-functionalized thermally carbonized porous silicon nanoparticles (APSTCPSi NPs), forming a surface negatively charged nanovehicle with unique properties. This polymer conjugated NPs could modify surface smoothness, charge, and hydrophilicity of the developed NPs, leading to considerable improvement in the colloidal and plasma stabilities via enhanced suspensibility and charge repulsion. Furthermore, despite the surface negative charge of the polymer-conjugated NPs, the cellular internalization was increased in both MDA-MB-231 and MCF-7 breast cancer cells. These results provide a proof-of-concept evidence that such polymer-based PSi nanocomposite can be extensively used as a promising candidate for intracellular drug delivery. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The rapid detection of methyl tert-butyl ether (MtBE) in water using a prototype gas sensor system.

Science.gov (United States)

de Lacy Costello, B P J; Sivanand, P S; Ratcliffe, N M; Reynolds, D M

2005-01-01

The gasoline additive Methyl-tertiary-Butyl Ether (MtBE) is the second most common contaminant of groundwater in the USA and represents an important soil contaminant. This compound has been detected in the groundwater in at least 27 states as a result of leaking underground storage facilities (gasoline storage tanks and pipelines). Since the health effects of MtBE are unclear the potential threat to drinking water supplies is serious. Therefore, the ability to detect MtBE at low levels (ppb) and on-line at high-risk groundwater sites would be highly desirable. This paper reports the use of 'commercial' and metal oxide sensor arrays for the detection of MtBE in drinking and surface waters at low ppb level (microg.L(-1) range). The output responses from some of the sensors were found to correlate well with MtBE concentrations under laboratory conditions.

Separator Membrane from Crosslinked Poly(Vinyl Alcohol and Poly(Methyl Vinyl Ether-alt-Maleic Anhydride

Directory of Open Access Journals (Sweden)

Charu Vashisth Rohatgi

2015-03-01

Full Text Available In this work, we report separator membranes from crosslinking of two polymers, such as poly vinyl alcohol (PVA with an ionic polymer poly(methyl vinyl ether-alt-maleic anhydride (PMVE-MA. Such interpolymer-networked systems were extensively used for biomedical and desalination applications but they were not examined for their potential use as membranes or separators for batteries. Therefore, the chemical interactions between these two polymers and the influence of such crosslinking on physicochemical properties of the membrane are systematically investigated through rheology and by critical gel point study. The hydrogen bonding and the chemical interaction between PMVE-MA and PVA resulted in highly cross-linked membranes. Effect of the molecular weight of PVA on the membrane properties was also examined. The developed membranes were extensively characterized by studying their physicochemical properties (water uptake, swelling ratio, and conductivity, thermal and electrochemical properties using differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, thermo-gravimetric analysis (TGA and electrochemical impedance spectroscopy (EIS. The DSC study shows the presence of a single Tg in the membranes indicating compatibility of the two polymers in flexible and transparent films. The membranes show good stability and ion conductivity suitable for separator applications.

Separator Membrane from Crosslinked Poly(Vinyl Alcohol) and Poly(Methyl Vinyl Ether-alt-Maleic Anhydride)

Science.gov (United States)

Rohatgi, Charu Vashisth; Dutta, Naba K.; Choudhury, Namita Roy

2015-01-01

In this work, we report separator membranes from crosslinking of two polymers, such as poly vinyl alcohol (PVA) with an ionic polymer poly(methyl vinyl ether-alt-maleic anhydride) (PMVE-MA). Such interpolymer-networked systems were extensively used for biomedical and desalination applications but they were not examined for their potential use as membranes or separators for batteries. Therefore, the chemical interactions between these two polymers and the influence of such crosslinking on physicochemical properties of the membrane are systematically investigated through rheology and by critical gel point study. The hydrogen bonding and the chemical interaction between PMVE-MA and PVA resulted in highly cross-linked membranes. Effect of the molecular weight of PVA on the membrane properties was also examined. The developed membranes were extensively characterized by studying their physicochemical properties (water uptake, swelling ratio, and conductivity), thermal and electrochemical properties using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermo-gravimetric analysis (TGA) and electrochemical impedance spectroscopy (EIS). The DSC study shows the presence of a single Tg in the membranes indicating compatibility of the two polymers in flexible and transparent films. The membranes show good stability and ion conductivity suitable for separator applications. PMID:28347019

Gasoline ether oxygenate occurrence in Europe, and a review of their fate and transport characteristics in the environment

Energy Technology Data Exchange (ETDEWEB)

Stupp, D.; Gass, M.; Leiteritz, H. [Dr. Stupp Consulting DSC, Tauw, Bergisch Gladbach (Germany); Pijls, C. [TAUW, Apeldoorn (Netherlands); Thornton, S. [University of Sheffield, Sheffield (United Kingdom); Smith, J.; Dunk, M.; Grosjean, T.; Den Haan, K. [CONCAWE, Brussels (Belgium)

2012-06-15

Ether oxygenates are added to certain gasoline (petrol) formulations to improve combustion efficiency and to increase the octane rating. In this report the term gasoline ether oxygenates (GEO) refers collectively to methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), diisopropyl ether (DIPE), tertiary amyl ethyl ether (TAEE), tertiary hexyl methyl ether (THxME), and tertiary hexyl ethyl ether (THxEE), as well as the associated tertiary butyl alcohol (TBA). This report presents newly collated data on the production capacities and use of MTBE, ETBE, TAME, DIPE and TBA in 30 countries (27 EU countries and Croatia, Norway and Switzerland) to inform continued and effective environmental management practices for GEO by CONCAWE members. The report comprises data on gasoline use in Europe that were provided by CONCAWE and obtained from the European Commission. Furthermore Societe Generale de Surveillance (SGS) provided detailed analytical data (more than 1,200 sampling campaigns) on the GEO composition of gasoline in European countries in the period 2000-2010. Another major aspect of this report is the investigation of GEO distribution in groundwater, drinking water, surface water, runoff water, precipitation (rain/snow) and air in the European environment. Apart from the general sources of literature for the study, local environmental authorities and institutes in the 30 European countries have been contacted for additional information. Finally, a review of the international literature on GEO natural attenuation processes was undertaken with a focus on international reports and peer-reviewed scientific publications to give an overview on the known fate, transport and degradation mechanisms of GEO in the subsurface, to inform risk-management strategies that may rely on natural attenuation processes. The literature reveals that all GEO compounds used in fuels are highly water soluble and weakly retarded by aquifer

Nickel-Catalyzed Alkoxy-Alkyl Interconversion with Alkylborane Reagents through C−O Bond Activation of Aryl and Enol Ethers

KAUST Repository

Guo, Lin

2016-11-07

A nickel-catalyzed alkylation of polycyclic aromatic methyl ethers as well as methyl enol ethers with B-alkyl 9-BBN and trialkylborane reagents that involves the cleavage of stable C(sp2)−OMe bonds is described. The transformation has a wide substrate scope and good chemoselectivity profile while proceeding under mild reaction conditions; it provides a versatile way to form C(sp2)−C(sp3) bonds that does not suffer from β-hydride elimination. Furthermore, a selective and sequential alkylation process by cleavage of inert C−O bonds is presented to demonstrate the advantage of this method.

Effects of secretagogues on ATP levels and protein carboxyl methylation in rat brain synaptosomes

International Nuclear Information System (INIS)

Bjorndahl, J.M.; Rutledge, C.O.

1986-01-01

The influence of various substances which are known to alter free intracellular calcium concentrations on protein carboxyl methyltransferase (PCM) activity was investigated in rat brain synaptosomes. The synaptosomes were labeled with L-[ 3 H]methionine and the 3 H-methyl esters of proteins were formed from the methyl donor S-[ 3 H]adenosyl-L-methionine ([ 3 H]AdoMet). The calcium ionophore A23187 and ouabain decreased PCM activity and the decrease produced by A23187 was antagonized by ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid and MnCl 2 . On the other hand, ruthenium red, an inhibitor of calcium uptake, stimulated PCM activity. These data suggest that PCM activity is inversely related to the free cytoplasmic calcium concentration. Veratridine, A23187 and elevated potassium ions decreased the levels of ATP and [ 3 H]AdoMet. The A23187-mediated decrease in ATP levels and the reduced [ 3 H]AdoMet formation was antagonized by ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid and MnCl 2 . Inhibition of metabolic activity of the synaptosomes by NaCN led to: decreased ATP levels; inhibition of [3H]AdoMet formation; and inhibition of PCM activity. These data suggest that the decrease in protein methylation produced by secretagogues is associated with an increase in the concentration of free intracellular calcium which results in a decrease in the metabolically active pool of ATP. This leads to a decreased rate of AdoMet formation, a cosubstrate for PCM and a resultant decrease in PCM activity

Involvement of a novel enzyme, MdpA, in methyl tert-butyl ether degradation in Methylibium petroleiphilum PM1.

Science.gov (United States)

Schmidt, Radomir; Battaglia, Vince; Scow, Kate; Kane, Staci; Hristova, Krassimira R

2008-11-01

Methylibium petroleiphilum PM1 is a well-characterized environmental strain capable of complete metabolism of the fuel oxygenate methyl tert-butyl ether (MTBE). Using a molecular genetic system which we established to study MTBE metabolism by PM1, we demonstrated that the enzyme MdpA is involved in MTBE removal, based on insertional inactivation and complementation studies. MdpA is constitutively expressed at low levels but is strongly induced by MTBE. MdpA is also involved in the regulation of tert-butyl alcohol (TBA) removal under certain conditions but is not directly responsible for TBA degradation. Phylogenetic comparison of MdpA to related enzymes indicates close homology to the short-chain hydrolyzing alkane hydroxylases (AH1), a group that appears to be a distinct subfamily of the AHs. The unique, substrate-size-determining residue Thr(59) distinguishes MdpA from the AH1 subfamily as well as from AlkB enzymes linked to MTBE degradation in Mycobacterium austroafricanum.

A new cytotoxic sterol methoxymethyl ether from a deep water marine sponge Scleritoderma sp. cf. paccardi.

Science.gov (United States)

Gunasekera, S P; Kelly-Borges, M; Longley, R E

1996-02-01

24(R)-Methyl-5 alpha-cholest-7-enyl 3 beta-methoxymethyl ether (1), a new sterol ether, has been isolated from a deep-water marine sponge Scleritoderma sp. cf. paccardi. Compound 1 exhibited in vitro cytotoxicity against the cultured murine P-388 tumor cell line with an IC50 of 2.3 micrograms/mL. The isolation and structure elucidation of 1 by NMR spectroscopy is described.

Synthesis of hydroxylated and methoxylated polybrominated diphenyl ethers

Institute of Scientific and Technical Information of China (English)

ZHENG Ke-wen; GAO Li-ping; CAO Jie; YU Hai-wen; ZHANG Zhang

2009-01-01

Hydroxylated/methoxylated polybrominated diphenyl ethers (OH/MeO-PBDEs) are not only detected as natural products, but also regarded as metabolites formed from polybrominated diphenyl ethers (PBDEs), which are widely used as flame-retardants in various materials. The aim of the present study was to synthesize authentic OH-PBDEs and MeO-PBDEs, as reference standards for environmental exploration. Twenty OH-PBDEs and their corresponding MeO-PBDEs containing three to six bromine atoms were synthesized via a trial of reactions including coupling, oxidation, bromination, methylation, etc. The products were characterized by GC-MS and 1H-NMR spectroscopy in the work. As results show, all compounds synthesized were up to 99% on purity and be reqarded as authentic standards for detecting the chemical pollutants in the emvironment.

Diethyl Ether Production Process with Various Catalyst Type

Directory of Open Access Journals (Sweden)

Widayat

2013-01-01

Full Text Available Several H-zeolite and HZSM-5 catalysts was preparated and their characters have also been investigated. H-zeolit Catalyst was preparated from Natural Zeolite that obtained from Malang District and Gunung Kidul District. Diethyl ether was produced by Ethanol with concentration of 95%. This research use fixed bed reactor that 1 gram of catalyst as bed catalyst, atmospheric pressure and temperature 140oC as the operating condition. Ethanol vapor from vaporization tank was driven by 200 ml/min Nitrogen stream. The responds in this research is liquid product concentration; diethyl ether, ethanol, methanol and water concentration. The results showed that the largest ethanol conversion was produced by the use of 56.44% HZSM-5 and the largest yield of diethyl ether diethyl was produced by the use of alumina and H-zeolite catalyst. The larger ratio between natural zeolite with HCl solvent will produce the larger surface area of catalyst and ethanol conversion. The largest ethanol conversion was produced at reactan ratio 1:20.

Temperature-Dependent Alkyl Glycerol Ether Lipid Composition of Mesophilic and Thermophilic Sulfate-Reducing Bacteria

Directory of Open Access Journals (Sweden)

Arnauld Vinçon-Laugier

2017-08-01

Full Text Available The occurrence of non-isoprenoid alkyl glycerol ether lipids in Bacteria and natural environments is increasingly being reported and the specificity and diagenetic stability of these lipids make them powerful biomarkers for biogeochemical and environmental studies. Yet the environmental controls on the biosynthesis of these peculiar membrane lipids remain poorly documented. Here, the lipid content of two mesophilic (Desulfatibacillum aliphaticivorans and Desulfatibacillum alkenivorans and one thermophilic (Thermodesulfobacterium commune sulfate-reducing bacteria—whose membranes are mostly composed of ether lipids—was investigated as a function of growth temperature (20–40°C and 54–84°C, respectively. For all strains, the cellular lipid content was lower at sub- or supra-optimal growth temperature, but the relative proportions of dialkyl glycerols, monoalkyl glycerols and fatty acids remained remarkably stable whatever the growth temperature. Rather than changing the proportions of the different lipid classes, the three strains responded to temperature changes by modifying the average structural composition of the alkyl and acyl chains constitutive of their membrane lipids. Major adaptive mechanisms concerned modifications of the level of branching and of the proportions of the different methyl branched lipids. Specifically, an increase in temperature induced mesophilic strains to produce less dimethyl branched dialkyl glycerols and 10-methyl branched lipids relative to linear structures, and the thermophilic strain to decrease the proportion of anteiso relative to iso methyl branched compounds. These modifications were in agreement with a regulation of the membrane fluidity. In one mesophilic and the thermophilic strains, a modification of the growth temperature further induced changes in the relative proportions of sn-2 vs sn-1 monoalkyl glycerols, suggesting an unprecedented mechanism of homeoviscous adaptation in Bacteria. Strong

Involvement of a Novel Enzyme, MdpA, in Methyl tert-Butyl Ether Degradation in Methylibium petroleiphilum PM1 ▿

Science.gov (United States)

Schmidt, Radomir; Battaglia, Vince; Scow, Kate; Kane, Staci; Hristova, Krassimira R.

2008-01-01

Methylibium petroleiphilum PM1 is a well-characterized environmental strain capable of complete metabolism of the fuel oxygenate methyl tert-butyl ether (MTBE). Using a molecular genetic system which we established to study MTBE metabolism by PM1, we demonstrated that the enzyme MdpA is involved in MTBE removal, based on insertional inactivation and complementation studies. MdpA is constitutively expressed at low levels but is strongly induced by MTBE. MdpA is also involved in the regulation of tert-butyl alcohol (TBA) removal under certain conditions but is not directly responsible for TBA degradation. Phylogenetic comparison of MdpA to related enzymes indicates close homology to the short-chain hydrolyzing alkane hydroxylases (AH1), a group that appears to be a distinct subfamily of the AHs. The unique, substrate-size-determining residue Thr59 distinguishes MdpA from the AH1 subfamily as well as from AlkB enzymes linked to MTBE degradation in Mycobacterium austroafricanum. PMID:18791002

Functionalized mesoporous silicas with crown ether moieties for selective adsorption of lithium ions in artificial sea water.

Science.gov (United States)

Sung, Soo Park; Moorthy, Madhappan Santha; Song, Hyun-Jin; Ha, Chang-Sik

2014-11-01

Lithium ion has been increasingly recognized in a wide range of industrial applications. In this work, we studied on the adsorption of Li+ in the artificial seawater with high selectivity using methyl-crown ether (AC-SBA-15) and aza-crown ether (HMC-SBA-15) moieties-functionalized mesoporous silica materials. First, methyl-crown ether and aza-crown ether moieties-functionalized mesoporous silica materials were synthesized via two-step post-synthesis process using a grafting method. The functionalized materials were employed to the metal ion adsorption from aqueous solution (artificial seawater) containing Li+, Co2+, Cr3+ and Hg2+. The prepared hybrid material showed high selectivity for Li+ ion in the artificial seawater at pH 8.0. The absorbed amount of Li+ was 73 times higher than Cr3+ for aza-crown ether containing AC-SBA-15 as an absorbent. The absorbed amount of Co2+ (4.5 x 10(-5) mol/g), Cr3+ (1.5 x 10(-5) mol/g) and Hg2+ (2.25 x 10(-4) mol/g) were remarkably lower than the case of Li+. On the other hand, the absorbed amount of various metal ions of HMC-SBA-15 with amine groups in alky chains and crown ether moieties were 1.1 x 10(-3) mol/g for Li+, 5.0 x 10(-5) mol/g for Co2+, 2.9 x 10(-4) mol/g for Cr3+, 2.8 x 10(-4) mol/g for Hg2+ mol/g, respectively.

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

Science.gov (United States)

2010-04-01

... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to the...

Naturally occurring methyl salicylate glycosides.

Science.gov (United States)

Mao, Ping; Liu, Zizhen; Xie, Meng; Jiang, Rui; Liu, Weirui; Wang, Xiaohong; Meng, Shen; She, Gaimei

2014-01-01

As an important part of non steroids anti-inflammation drug (NSAIDs), salicylate has developed from natural substance salicylic acid to natrium salicylicum, to aspirin. Now, methyl salicylate glycoside, a new derivative of salicylic acid, is modified with a -COOH group integrated one methyl radical into formic ether, and a -OH linked with a monosaccharide, a disaccharide or a trisaccharide unit by glycosidic linkage. It has the similar pharmacological activities, anti-inflammatory, analgesic, antipyretic and antithrombotic as the previous salicylates' without resulting in serious side effects, particularly the gastrointestinal toxicity. Owing to the superiority of those significant bioactivities, methyl salicylate glycosides have became a hot research area in NSAIDs for several years. This paper compiles all 9 naturally occurring methyl salicylate glycosides, their distribution of the resource and pharmacological mechanism, which could contribute to the new drug discovery.

Refractive microlenses produced by excimer laser machining of poly(methyl methacrylate)

DEFF Research Database (Denmark)

Jensen, Martin Frøhling; Krühne, Ulrich; H., L.

2005-01-01

A method has been developed whereby refractive microlenses can be produced in poly (methyl methacrylate) by excimer laser irradiation at λ = 248 nm. The lenses are formed by a combined photochemical and thermal process. The lenses are formed as depressions in the substrate material (negative foca...

Developmental toxicity evaluation of inhaled tertiary amyl methyl ether in mice and rats.

Science.gov (United States)

Welsch, Frank; Elswick, Barbara; James, R Arden; Marr, Melissa C; Myers, Christina B; Tyl, Rochelle W

2003-01-01

This evaluation was part of a much more comprehensive testing program to characterize the mammalian toxicity potential of the gasoline oxygenator additive tertiary amyl methyl ether (TAME), and was initiated upon a regulatory agency mandate. A developmental toxicity hazard identification study was conducted by TAME vapor inhalation exposure in two pregnant rodent species. Timed-pregnant CD(Sprague-Dawley) rats and CD-1 mice, 25 animals per group, inhaled TAME vapors containing 0, 250, 1500 or 3500 ppm for 6 h a day on gestational days 6-16 (mice) or 6-19 (rats). The developmental toxicity hazard potential was evaluated following the study design draft guidelines and end points proposed by the United States Environmental Protection Agency. Based on maternal body weight changes during pregnancy, the no-observable-adverse-effect level (NOAEL) was 250 ppm for maternal toxicity in rats and 1500 ppm for developmental toxicity in rats using the criterion of near-term fetal body weights. In mice, more profound developmental toxicity was present than in rats, at both 1500 and 3500 ppm. At the highest concentration, mouse litters revealed more late fetal deaths, significantly reduced fetal body weights per litter and increased incidences of cleft palate (classified as an external malformation), as well as enlarged lateral ventricles of the cerebrum (a visceral variation). At 1500 ppm, mouse fetuses also exhibited an increased incidence of cleft palate and the dam body weights were reduced. Therefore, the NOAEL for the mouse maternal and developmental toxicity was 250 ppm under the conditions of this study. Copyright 2003 John Wiley & Sons, Ltd.

Stereoselective synthesis of highly substituted bicyclic γ-lactones using homoaldol addition of 1-(1-cycloalkenyl)methyl carbamates

DEFF Research Database (Denmark)

Özlügedik, M.; Kristensen, Jesper Langgaard; Reuber, J.

2004-01-01

Stereoselective addition of aldehydes 4 to metallated 1-(1-cycloalkenyl) methyl N,N-diisopropylcarbamates 1 gave cyclic homoaldol adducts 6. By applying the (-)-sparteine method, enantiomerically enriched products were obtained. These were oxidatively cyclized to diastereomerically pure ¿-lactones...... 8 via the ¿-lactol ethers 7. After deprotonation of ¿-lactones 8 with lithium hexamethyldisilazide, a further substitution was achieved. By trapping the lactone enolates 11 with ß-naphthylmethyl bromide, single diastereomers of ¿-lactones 12 were produced....

The 11C-radioisotopic study of methanol conversion on V-MCM-41; the influence of methyl iodide on the transformation

International Nuclear Information System (INIS)

Sarkadi-Priboczki, E.; Szelecsenyi, F.; Kovacs, Z.; Solmaz, A.; Balci, S.; Dogu, T.

2007-01-01

Complete text of publication follows. The MCM-41 mesoporous material has Lewis and even Bronsted acid sites to produce dimethyl ether with some hydrocarbons, while over metal modified MCM-41 mostly formaldehyde and dimethoxy methane (i.e. methylal) or methyl formate are produced. In present experiments V incorporated basically mild acid sites of MCM-41 was prepared by low temperature direct synthesis. The V-MCM-41 has enough main active Lewis sites (by V-) to form formaldehyde and also light Bronsted acid sites to let the adsorbed formaldehyde eliminate and afterwards, with methanol, to form dimethoxy methane in nonoxidative environment. This V-MCM-41 has been tested by ethanol conversion in non-oxidative environments too and diethoxy methane as main product was detected. In present work the methanol conversion, as well as the methanol co-reaction with methyl iodide are studied from the same V-MCM-41 sample using 11 C-technique. The 11 C-labelled radioactive methanol has been already applied for determination of methanol conversion rates on Cu-modified MCM-41. The V-MCM-41 was prepared by direct hydrothermal synthesis method. The adsorption rate of 11 C-methanol and, after the reaction, the desorption rate of the remaining 11 C-derivatives on catalyst were continuously detected by gamma detectors. The derivatives were analyzed by radio-gas chromatography (gas chromatograph with FID coupled on-line with a radioactivity detector). Both dimethyl ether and hydrocarbon formation are also in slight degrees according to weak Lewis and Bronsted acidities. Since the conversion was carried out without added oxygen gas, only the frame oxygen can take part into catalysis. In presence of non-radioactive methyl iodide, the radioactive methanol is converted to radioactive methyl iodide on V-MCM-41. The radio-GC analysis confirmed that the iodide induced change of the reaction performance was reversible i.e. the radioactive methyl iodide was regenerated to non-radioactive methyl

Methyl tert-butyl ether biodegradation by indigenous aquifer microorganisms under natural and artificial oxic conditions

Science.gov (United States)

Landmeyer, J.E.; Chapelle, F.H.; Herlong, H.H.; Bradley, P.M.

2001-01-01

Microbial communities indigenous to a shallow groundwater system near Beaufort, SC, degraded milligram per liter concentrations of methyl tert-butyl ether (MTBE) under natural and artificial oxic conditions. Significant MTBE biodegradation was observed where anoxic, MTBE-contaminated groundwater discharged to a concrete-lined ditch. In the anoxic groundwater adjacent to the ditch, concentrations of MTBE were > 1 mg/L. Where groundwater discharge occurs, dissolved oxygen (DO) concentrations beneath the ditch exceeded 1.0 mg/L to a depth of 1.5 m, and MTBE concentrations decreased to CO2 in laboratory liquid culture studies, with no accumulation of intermediate compounds. Upgradient of the ditch in the anoxic, MTBE and BTEX-contaminated aquifer, addition of a soluble oxygen release compound resulted in oxic conditions and rapid MTBE biodegradation by indigenous microorganisms. In an observation well located closest to the oxygen addition area, DO concentrations increased from 0.4 to 12 mg/L in <60 days and MTBE concentrations decreased from 20 to 3 mg/L. In the same time period at a downgradient observation well, DO increased from <0.2 to 2 mg/L and MTBE concentrations decreased from 30 to <5 mg/L. These results indicate that microorganisms indigenous to the groundwater system at this site can degrade milligram per liter concentrations of MTBE under natural and artificial oxic conditions.

Risk characterization of methyl tertiary butyl ether (MTBE) in tap water.

Science.gov (United States)

Stern, B R; Tardiff, R G

1997-12-01

Methyl tertiary butyl ether (MTBE) can enter surface water and groundwater through wet atmospheric deposition or as a result of fuel leaks and spills. About 30% of the U.S. population lives in areas where MTBE is in regular use. Ninety-five percent of this population is unlikely to be exposed to MTBE in tap water at concentrations exceeding 2 ppb, and most will be exposed to concentrations that are much lower and may be zero. About 5% of this population may be exposed to higher levels of MTBE in tap water, resulting from fuel tank leaks and spills into surface or groundwater used for potable water supplies. This paper describes the concentration ranges found and anticipated in surface and groundwater, and estimates the distribution of doses experienced by humans using water containing MTBE to drink, prepare food, and shower/bathe. The toxic properties (including potency) of MTBE when ingested, inhaled, and in contact with the skin are summarized. Using a range of human toxic potency values derived from animal studies, margins of exposure (MOE) associated with alternative chronic exposure scenarios are estimated to range from 1700 to 140,000. Maximum concentrations of MTBE in tap water anticipated not to cause adverse health effects are determined to range from 700 to 14,000 ppb. The results of this analysis demonstrate that no health risks are likely to be associated with chronic and subchronic human exposures to MTBE in tap water. Although some individuals may be exposed to very high concentrations of MTBE in tap water immediately following a localized spill, these exposures are likely to be brief in duration due to large-scale dilution and rapid volatilization of MTBE, the institution of emergency response and remediation measures to minimize human exposures, and the low taste and odor thresholds of MTBE which ensure that its presence in tap water is readily detected at concentrations well below the threshold for human injury.

Complexity of Naturally Produced Polybrominated Diphenyl Ethers Revealed via Mass Spectrometry

Science.gov (United States)

Agarwal, Vinayak; Li, Jie; Rahman, Imran; Borgen, Miles; Aluwihare, Lihini I.; Biggs, Jason S.; Paul, Valerie J.; Moore, Bradley S.

2015-01-01

Polybrominated diphenyl ethers (PBDEs) are persistent and bioaccumulative anthropogenic and natural chemicals that are broadly distributed in the marine environment. PBDEs are potentially toxic due to inhibition of various mammalian signaling pathways and enzymatic reactions. PBDE isoforms vary in toxicity in accordance with structural differences, primarily in the number and pattern of hydroxyl moieties afforded upon a conserved core structure. Over four decades of isolation and discovery-based efforts have established an impressive repertoire of natural PBDEs. Based on our recent reports describing the bacterial biosyntheses of PBDEs, we predicted the presence of additional classes of PBDEs to those previously identified from marine sources. Using mass spectrometry and NMR spectroscopy, we now establish the existence of new structural classes of PBDEs in marine sponges. Our findings expand the chemical space explored by naturally produced PBDEs, which may inform future environmental toxicology studies. Furthermore, we provide evidence for iodinated PBDEs and direct attention toward the contribution of promiscuous halogenating enzymes in further expanding the diversity of these polyhalogenated marine natural products. PMID:25559102

Ferrocene Compounds. XXVI. C- and O-Ferrocenylalkylation of Methyl Salicylate

OpenAIRE

Kovač, Veronika; Rapić, Vladimir; Alagić, Jasmina; Barišić, Lidija

1999-01-01

Reaction of equimolar amounts of methyl salicylate, sodium and N,N,N-trimethylferrocylammonium iodide (1a) in ethanol gave 55% of ethyl 1-ferrocenylethyl ether (4). By refluxing a solution of 9 mmol sodium and 3 mmol of FcCHRNMe3I (1a, R = H; 1b, R = Me; 1c, R = Ph) in a large excess of methyl salicylate for 2-3 hours, the corresponding methyl 5-ferrocylsalicylates (5) (10-23%) and methyl-3-ferrocylsalicylates (6) (12-20%) were obtained. During conversion of salt 1b, besides of 5b and 6b, 20%...

Calcium carbonate growth in the presence of water soluble cellulose ethers

International Nuclear Information System (INIS)

Zhang Fengju; Yang Xinguo; Tian Fei

2009-01-01

Calcium carbonate precipitation was performed in the presence of methyl cellulose (MC) and two kinds of hydroxyethyl cellulose (HEC FD-10000, HEC FD-30000). The results demonstrated that the final product morphology and structure of CaCO 3 crystals are highly sensitive to the concentration of the cellulose ethers aqueous solution. By precisely controlling their concentrations, all these three cellulose ethers solutions have the ability of protecting metastable vaterite from thermodynamically transforming into stable calcite. The intermediate products investigation showed to some extent the phase transformation of calcium carbonate in its growing process from metastable vaterite to calcite and indicated that the calcium carbonate crystal growth in HEC solutions occurs through dissolution and reprecipitation process. Calcium carbonate growth in both presence of HEC and ethanol or Mg 2+ was also examined. This work demonstrates the potential of water soluble cellulose ethers in controlling biominerals crystallization and growth. The results are revelatory for biomineralization and fabricating new organic-inorganic hybrids based on cellulose derivatives.

The Formation of Polycomplexes of Poly(Methyl Vinyl Ether-Co-Maleic Anhydride and Bovine Serum Albumin in the Presence of Copper Ions

Directory of Open Access Journals (Sweden)

Karahan Mesut

2014-09-01

Full Text Available The binary and ternary complex formations of poly(methyl vinyl ether-co-maleic anhydride (PMVEMA with copper ions and with bovine serum albumin (BSA in the presence of copper ions in phosphate buffer solution at pH = 7 were examined by the techniques of UV-visible, fluorescence, dynamic light scattering, atomic force microscopy measurements. In the formation of binary complexes of PMVEMA-Cu(II, the addition of copper ions to the solution of PMVEMA in phosphate buffer solution at pH = 7 forms homogeneous solutions when the molar ratio of Cu(II/MVEMA is 0.5. Then the formations of ternary complexes of PMVEMA-Cu(II-BSA were examined. Study analysis revealed that the toxicities of polymer-metal and polymer-metal-protein mixture solutions depend on the nature and ratio of components in mixtures.

Reductions in greenhouse gas emissions and oil use by DME (di-methyl ether) and FT (Fischer-Tropsch) diesel production in chemical pulp mills

International Nuclear Information System (INIS)

Joelsson, Jonas M.; Gustavsson, Leif

2012-01-01

Using energy systems analysis, we examine the potential to reduce CO 2 emissions and oil use by integrating motor biofuel production with pulp mills. BLG-DME (black liquor gasification with di-methyl ether production) is compared with solid biomass gasification with BIG-FT (solid biomass gasification with Fischer-Tropsch fuel production). The studied systems are expanded with stand-alone production of biomass-based electricity and motor fuel so that they yield the same functional unit in terms of motor fuel and electricity as well as pulp or paper product, in order to facilitate comparison. More motor biofuel can be produced in integration with the studied mills with BLG-DME than with BIG-FT because the black liquor flow is large compared with other fuel streams in the mill and the integration potential for BIG-FT is limited by the mill’s heat demand. When both systems are required to produce the same functional unit, the BLG-DME system achieves higher system efficiency and larger reductions in CO 2 emissions and oil use per unit of biomass consumed. In general, integration of motor biofuel production with a pulp mill is more efficient than stand-alone motor biofuel production. Larger reductions in CO 2 emissions or oil use can, however, be achieved if biomass replaces coal or oil in stationary applications. -- Highlights: ► CO 2 emission and oil use reductions quantified for pulp mill-based biorefineries. ► Black liquor gasification gives larger reductions than solid biomass gasification. ► Lower mill steam demand increases the black liquor gasification advantage. ► Biomass directly replacing coal or oil in stationary plants gives larger reductions.

[Biodegradation of methyl tert-butyl ether by stabilized immobilized Methylibium petroleiphilum PM1 cells and its biodegradation kinetics analysis].

Science.gov (United States)

Cheng, Zhuo-wei; Fu, Ling-xiao; Jiang, Yi-feng; Chen, Jian-meng; Zhang, Rong

2011-05-01

Methylibium petroleiphilum PM1, which is capable of degrading methyl tert-butyl ether (MTBE) , was immobilized in calcium alginate gel beads. Several methods were explored to increase the strength of these gel beads. The central composite design analysis indicated that the introduction of 0.2 mol x L(-1) Ca2+ into the crosslinking solution, 1.38 mmol x L(-1) Ca2+ into the growth medium and 0.1% polyethyleneimine (PEI) as the chemical crosslinking agent could increase the stability of the Ca-alginate gel beads with no loss of biodegradation activity. The stabilized immobilized cells could be used 400 h continuously with no breakage and no bioactivity loss. Examination of scanning electron microscope demonstrated that a membrane surrounding the gel beads was formed and the cells could grow and breed well in the stabilized calcium alginate gel beads. Kinetic analysis of the gel bead-degradation indicated that the rate-limiting step was biochemical process instead of intraparticle diffusion process. The diameter of 3 mm affected the biodegradability less while high concentration of PEI induced much more serious mass transfer restraint.

Interaction parameters of poly(vinyl methyl ether) in 2-propanol-water mixture as determined by small-angle neutron scattering

International Nuclear Information System (INIS)

Takada, Masako; Kurita, Kimio; Okano, Koji; Furusaka, Michihiro.

1994-01-01

The small-angle neutron scattering from semidilute solutions of poly(vinyl methyl ether)(PVME) in a 2-propanol-water mixture has been measured, the volume concentration of 2-propanol in the aqueous solvent being 10%, in the temperature range just below the lower critical solution temperature(LCST). The binary and ternary cluster integrals of polymer segments were determined from the concentration dependence of the correlation length at each temperature. We have calculated the contribution of segment-segment interaction to the entropy, S int and enthalpy, U int from the measured temperature dependences of these interaction parameters and found that both values are positive in accordance with the previously measured PVME-water system and PVME-(water+methanol) system. However, the value of S int for PVME-(water+2-propanol) system is larger than that for PVME-(water+methanol) system having the same alcohol concentration, and it is even larger than that for PVME-water system. This anomalous behavior is explained as due to the preferential solvation of 2-propanol molecules to the segments of PVME. (author)

Characterization of melt-blended graphene – poly(ether ether ketone) nanocomposite

International Nuclear Information System (INIS)

Tewatia, Arya; Hendrix, Justin; Dong, Zhizhong; Taghon, Meredith; Tse, Stephen; Chiu, Gordon; Mayo, William E.; Kear, Bernard; Nosker, Thomas; Lynch, Jennifer

2017-01-01

Using a high shear melt-processing method, graphene-reinforced polymer matrix composites (G-PMCs) were produced with good distribution and particle–matrix interaction of bi/trilayer graphene at 2 wt. % and 5 wt. % in poly ether ether ketone (2Gn-PEEK and 5Gn-PEEK). The morphology, structure, thermal properties, and mechanical properties of PEEK, 2Gn-PEEK and 5 Gn-PEEK were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), flexural mechanical testing, and dynamic mechanical analysis (DMA). Addition of graphene to PEEK induces surface crystallization, increased percent crystallinity, offers a composite that is thermally stable until 550 °C and enhances thermomechanical properties. Results show that graphene was successfully melt-blended within PEEK using this method.

Characterization of melt-blended graphene – poly(ether ether ketone) nanocomposite

Energy Technology Data Exchange (ETDEWEB)

Tewatia, Arya; Hendrix, Justin [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ, 08854 (United States); Dong, Zhizhong [Department of Mechanical Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854 (United States); Taghon, Meredith [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ, 08854 (United States); Tse, Stephen [Department of Mechanical Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854 (United States); Chiu, Gordon; Mayo, William E.; Kear, Bernard; Nosker, Thomas [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ, 08854 (United States); Lynch, Jennifer, E-mail: jklynch@rci.rutgers.edu [Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ, 08854 (United States)

2017-02-15

Using a high shear melt-processing method, graphene-reinforced polymer matrix composites (G-PMCs) were produced with good distribution and particle–matrix interaction of bi/trilayer graphene at 2 wt. % and 5 wt. % in poly ether ether ketone (2Gn-PEEK and 5Gn-PEEK). The morphology, structure, thermal properties, and mechanical properties of PEEK, 2Gn-PEEK and 5 Gn-PEEK were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), flexural mechanical testing, and dynamic mechanical analysis (DMA). Addition of graphene to PEEK induces surface crystallization, increased percent crystallinity, offers a composite that is thermally stable until 550 °C and enhances thermomechanical properties. Results show that graphene was successfully melt-blended within PEEK using this method.

Comparison of Properties among Dendritic and Hyperbranched Poly(ether ether ketones and Linear Poly(ether ketones

Directory of Open Access Journals (Sweden)

Atsushi Morikawa

2016-02-01

Full Text Available Poly(ether ether ketone dendrimers and hyperbranched polymers were prepared from 3,5-dimethoxy-4′-(4-fluorobenzoyldiphenyl ether and 3,5-dihydroxy-4′-(4-fluorobenzoyldiphenyl ether through aromatic nucleophilic substitution reactions. 1-(tert-Butyldimethylsiloxy-3,5-bis(4-fluorobenzoylbenzene was polycondensed with bisphenols, followed by cleavage of the protective group to form linear poly(ether ketones having the same hydroxyl groups in the side chains as the chain ends of the dendrimer and hyperbranched polymers. Their properties, such as solubilities, reduced viscosities, and thermal properties, were compared with one another. Similar comparisons were also carried out among the corresponding methoxy group polymers, and the size of the molecules was shown to affect the properties.

Enhancement of the Biodegradability of Methyl tert- Butyl Ether (MTBE by Advanced Oxidation

Directory of Open Access Journals (Sweden)

Mehraban Sadeghi

2006-06-01

Full Text Available The effectiveness of ozone treatment for improving the biodegradability of recalcitrant pollutants has been proved by investigating the ozonation reaction of Methyl tert-Butyl Ether (MTBE as a bioresistant gasoline oxygenate. Laboratory scale experiments have been carried out at room temperature by bubbling for 120 minutes ozonated air (3.4 ppm/min into 3 liter of an alkaline (pH=11.5 aqueous solution (100 mg/L of MTBE. The experimental results indicated that during the ozonation, complete MTBE degradation occurs in 100 minutes and after this time, ozone consumption goes on very slowly. At the end of the ozonation, after 100 minutes, the initial value of COD (256 mg O2/L is 98 and corresponds to a relative removal of about 62%. As for MTBE solution biodegradability expressed as (BOD5 / (COD ratio, during the first 90 minutes, its value regularly increases from lowest 0.01 up to a maximum of 0.68 that corresponds to an ozone consumption of 1.25 mg per each mg of COD initially present in the solution. The research showed that partial degradation of MTBE in the advanced oxidation processes results an increase in its biological degradation. But more oxidation results lower  (BOD5 / (COD ratio. Also the research showed that for idealization of the chemical oxidation conditions of MTBE, it needs to decrease COD to 46-68% before the biological degradation. The experimental results for determining the rate of MTBE removal due to stripping showed that about 14% of MTBE strips out after an hour of sparging with oxygen gas. The fraction of MTBE oxidized and/or striped increases to about 28% (in pH=7 and 70% (in pH=11.5 with ozonation over the same time period.

Numerical analysis of spray characteristics of dimethyl ether and diethyl ether fuel

International Nuclear Information System (INIS)

Mohan, Balaji; Yang, Wenming; Yu, Wenbin; Tay, Kun Lin

2017-01-01

Highlights: • Thermo-physical properties of liquid DME and DEE are reported. • Ether fuels tend to cavitate higher compared to that of diesel fuel. • Spray tip penetration and SMD are found to be lesser for ether fuels. • Ether fuels shows excellent atomization behavior. - Abstract: In this work, the spray characteristics of ether fuels such as dimethyl ether (DME) and diethyl ether (DEE) have been numerically investigated using KIVA-4 CFD code. A new hybrid spray model developed by coupling the standard KHRT model to cavitation sub model was used. The detailed thermo-physical properties of ether fuels have been predicted and validated with experimental results available from literature. The cavitation inception inside the injector nozzle hole has been studied for ether fuels in comparison with diesel fuel. It was found that ether fuels cavitates higher compared to that of conventional diesel fuel because of its low viscosity. The spray tip penetration of diesel fuel was longer than that of ether fuels due to high viscosity and density of diesel fuel. Ether fuels characterized by low Ohnesorge number and high Reynolds number showed better atomization behavior compared to that of the diesel fuel.

Reductions in greenhouse gas emissions and oil use by DME (di-methyl ether) and FT (Fischer-Tropsch) diesel production in chemical pulp mills

Energy Technology Data Exchange (ETDEWEB)

Joelsson, Jonas M., E-mail: joelsson.jonas@hotmail.com [Ecotechnology and Environmental Science, Mid Sweden University, SE-831 25 Oestersund (Sweden); Gustavsson, Leif [Linnaeus University, SE- 351 95 Vaexjoe (Sweden)

2012-03-15

Using energy systems analysis, we examine the potential to reduce CO{sub 2} emissions and oil use by integrating motor biofuel production with pulp mills. BLG-DME (black liquor gasification with di-methyl ether production) is compared with solid biomass gasification with BIG-FT (solid biomass gasification with Fischer-Tropsch fuel production). The studied systems are expanded with stand-alone production of biomass-based electricity and motor fuel so that they yield the same functional unit in terms of motor fuel and electricity as well as pulp or paper product, in order to facilitate comparison. More motor biofuel can be produced in integration with the studied mills with BLG-DME than with BIG-FT because the black liquor flow is large compared with other fuel streams in the mill and the integration potential for BIG-FT is limited by the mill's heat demand. When both systems are required to produce the same functional unit, the BLG-DME system achieves higher system efficiency and larger reductions in CO{sub 2} emissions and oil use per unit of biomass consumed. In general, integration of motor biofuel production with a pulp mill is more efficient than stand-alone motor biofuel production. Larger reductions in CO{sub 2} emissions or oil use can, however, be achieved if biomass replaces coal or oil in stationary applications. -- Highlights: Black-Right-Pointing-Pointer CO{sub 2} emission and oil use reductions quantified for pulp mill-based biorefineries. Black-Right-Pointing-Pointer Black liquor gasification gives larger reductions than solid biomass gasification. Black-Right-Pointing-Pointer Lower mill steam demand increases the black liquor gasification advantage. Black-Right-Pointing-Pointer Biomass directly replacing coal or oil in stationary plants gives larger reductions.

USAGE OF METHYL ESTER PRODUCED FROM WASTE GRAPE AND MN ADDITIVE AS ALTERNATIVE DIESEL FUEL

Directory of Open Access Journals (Sweden)

Hanbey Hazar

2017-06-01

Full Text Available In this study, methyl ester was produced from waste grape pulp sources. The produced methyl ester was mixed with diesel in different proportions, and was tested for engine performance and emission. It was found that with increasing biodiesel content, the specific fuel consumption and exhaust temperature have increased partially, while the CO, HC and smoke emissions decreased significantly. Additionally, in the scope of this study, dodecanol, propylene glycol and Mn based additives were added to fuel B50 to improve the emission and engine performance values. With the presence of additives, an increase in the exhaust temperature was observed, while a decrease in the specific fuel consumption, CO, HC, and smoke emissions were detected.

Development of natural rubber membranes for separation of methyl tert-butyl ether and methanol

International Nuclear Information System (INIS)

Nur Azrini Ramlee; Ghazali Mohd Nawawi; Khairul Zaman Dahlan

2010-01-01

As a new commercial process, membrane separation raises significant expectations in the process plant of the future and therefore this research was being initiated to develop and characterize pervaporation membrane based on natural rubber (NR). Natural Rubber SMR-L grade which was supplied by Malaysia Rubber Research Institute (MRRI) was used for the development of the membranes via interpenetrating polymer network (IPN) techniques. Polystyrene (PS) was used to modify the natural rubber to further improve their mechanical and chemical properties. The membranes were prepared with various blend ratios of natural rubber, polystyrene and divinyl benzene as cross linker with constant 1 % of dicumyl peroxide as the initiator. The developed membranes were then characterized to study the functional group presence, membranes morphology, crosslink density, tear strength, adsorption of the membranes and pervaporation separation of Methyl-Tert-Butyl-Ether (MTBE) and Methanol. Pervaporation process was conducted by using varies of MTBE concentration 10, 30, 50 and 70 wt % and at differ operation temperature, 25 degree Celsius and 55 degree Celsius. Separation performance of IPN NR/ PS membranes were based on the presented permeation flux and separation factor. Examination through Fourier Transform Infrared Spectroscopy (FTIR), determined crosslink density and tear strength, 6 series of IPN NR/ PS membranes were successfully developed using natural rubber. Observation from Scanning Electron Microscopy (SEM) showed that the membranes were dense and appropriated for the pervaporation process application. From the pervaporation of MTBE and Methanol, IPN NR/ PS membranes of series D4N30 shown low permeation flux of MTBE but high separation factor while D2N70 membranes was vice versa for both temperature of 25 degree Celsius and 55 degree Celsius. (author)

Isotopic exchange of cyclic ethers with deuterium over metal catalysts

International Nuclear Information System (INIS)

Duchet, J.C.; Cornet, D.

1976-01-01

The exchange reaction between deuterium and cyclic ethers (oxolane and α-methyl derivatives) has been investigated using rhodium and palladium catalysts. The first hydrogen undergoing exchange has been found to be located on a β-carbon. This fact, and the poisoning of the exchange of cyclopentane in the presence of ether, suggest that the O atom participates in the exchange mechanism of ethers. It appears, however, that the oxygen--metal bonding occurs only during this simple exchange process; simultaneous adsorption of oxygen and a vicinal carbon causes hydrogenolysis of the O--C bond. In each case multiple exchange is important. In the oxolane molecule two sets of exchangeable hydrogens are distinguished according to their reactivities, as could be expected by analogy with cycloalkanes. However, this distinction is not so clear in the exchange patterns of substituted oxolanes, since intermediate maxima are observed in these cases. It is suggested that the conformational properties of the substituted rings cause a constraint in the formation of 3,4-diadsorbed oxolanes. Thus, multiple exchange, based on α,β-process, and epimerization via the ''roll-over'' mechanism occur preferentially in certain parts of the molecules

Method detection limit determination and application of a convenient headspace analysis method for methyl tert-butyl ether in water.

Science.gov (United States)

O'Neill, Dennis T; Rochette, Elizabeth A; Ramsey, Philip J

2002-11-15

Methyl tert-butyl ether (MTBE) is a common groundwater contaminant, introduced to the environment by leaking petroleum storage tanks, urban runoff, and motorized watercraft. In this study. a simplified (static) headspace analysis method was adapted for determination of MTBE in water samples and soil water extracts. The MDL of the headspace method was calculated to be 2.0 microg L(-1) by the EPA single-concentration design method(1) and 1.2 microg L(-1) by a calibration method developed by Hubaux and Vos (Hubaux, A.; Vos, G. Anal. Chem. 1970,42, 849-855). The MDL calculated with the Hubaux and Vos method was favored because it considers both a true positive and a false positive. The static headspace method was applied to analysis of a tap water sample and a monitoring well sample from a gasoline service station, a river sample, and aqueous extracts from soil excavated during removal of a leaking underground storage tank (LUST). The water samples examined in this study had MTTBE concentrations ranging from 6 to 19 microg L(-1). Aqueous extracts of a soil sample taken from the LUST site had 8 microg L(-1) MTBE.

Assessing soil ecotoxicity of methyl tert-butyl ether using earthworm bioassay; closed soil microcosm test for volatile organic compounds

International Nuclear Information System (INIS)

An, Youn-Joo

2005-01-01

An earthworm bioassay was conducted to assess ecotoxicity in methyl tert-butyl ether (MTBE)-amended soils. Ecotoxicity of MTBE to earthworms was evaluated by a paper contact method, natural field soil test, and an OECD artificial soil test. All tests were conducted in closed systems to prevent volatilization of MTBE out of test units. Test earthworm species were Perionyx excavatus and Eisenia andrei. Mortality and abnormal morphology of earthworms exposed to different concentrations of MTBE were examined. MTBE was toxic to both earthworm species and the severity of response increased with increasing MTBE concentrations. Perionyx excavatus was more sensitive to MTBE than Eisenia andrei in filter papers and two different types of soils. MTBE toxicity was more severe in OECD artificial soils than in field soils, possibly due to the burrowing behavior of earthworms into artificial soils. The present study demonstrated that ecotoxicity of volatile organic compounds such as MTBE can be assessed using an earthworm bioassay in closed soil microcosm with short-term exposure duration. - Earthworm bioassay can be a good protocol to assess soil ecotoxicity of volatile organic compounds such as MTBE

Synthesis of Novel Ether Thionocarbamates and Study on Their Flotation Performance for Chalcopyrite

Directory of Open Access Journals (Sweden)

Gang Zhao

2016-09-01

Full Text Available Novel ether thionocarbamates, O-butoxy isopropyl-N-ethoxycarbonyl thionocarbamate (BIPECTC and O-(2-butoxy-1-methylethoxy isopropyl-N-ethoxycarbonyl thionocarbamate (BMIPECTC, were synthesized in this study. Their collecting efficiencies in the flotation of chalcopyrite were investigated using flotation tests, adsorption measurements, ultraviolet spectra (UV and Fourier transform-infrared spectroscopy (FT-IR and density functional theory (DFT calculations. The synthesized ether thionocarbamates showed better frothing properties than methyl-isobutyl-carbinol (MIBC and stronger affinity to chalcopyrite compared with O-isopropyl-N-ethyl thionocarbamate (IPETC and O-isobutyl-N-ethoxycarbonyl thionocarbamate (IBECTC. UV spectra analysis showed that the ether thionocarbamates react with Cu2+, with the exception of Fe2+, Ni2+, Zn2+ and Pb2+. Additionally, it was further confirmed by FTIR spectra that a chemical reaction occurs between copper ion and BIPECTC and BMIPECTC. The adsorption capacity measurements revealed that chalcopyrite exhibits good adsorption ability for ether thionocarbamates at an approximate pH of 8–10, which agrees with the flotation tests. The quantum chemistry calculation results indicated that the ether thionocarbamates exhibit stronger collecting ability for copper mineral in terms of frontier molecular orbital analysis, binding model simulation with copper ions and the molecular hydrophobicity compared with IPETC and IBECTC. The computational results are in very good agreement with the experimental results.

Validation of methodologies for the analysis of lead and methyl-ether in gasoline, using the techniques of atomic emission with plasma source coupled inductively and micellar liquid chromatography

International Nuclear Information System (INIS)

Redondo Escalante, M.

1995-01-01

This study established and optimized the experimental variables for the lead quantization through the Icp-Aes technique, in aqueous media. A comparative study of several proposal methods, that appears in the literature for the extraction in aqueous media of the lead in gasoline was made. It determined that it is not possible, to make this procedure using the reaction of hydrolysis of tetraethyl lead. The op tim conditions were established, for the lead quantization in gasoline, using methyl-isobutyl-ketone and also ethanol as dis solvents. The conditions of the proposed methodologies were optimized, and the variables of analytical performance were defined. It was demonstrated, that it is possible to prepare lead dissolution patterns, in organic media, starting from inorganic salts of this metal. The techniques of chromatography of gases and of liquid chromatography of high pressure, in the analysis of methyl-ter butyl-ether (Mtbe), were compared. It demonstrated that it is possible, to quantize the Mtbe through the HPLC technique, and it found that the 'micellar' liquid chromatography. (author) [es

Effect of degree of sulfonation and casting solvent on sulfonated poly(ether ether ketone) membrane for vanadium redox flow battery

Science.gov (United States)

Xi, Jingyu; Li, Zhaohua; Yu, Lihong; Yin, Bibo; Wang, Lei; Liu, Le; Qiu, Xinping; Chen, Liquan

2015-07-01

The properties of sulfonated poly(ether ether ketone) (SPEEK) membranes with various degree of sulfonation (DS) and casting solvent are investigated for vanadium redox flow battery (VRFB). The optimum DS of SPEEK membrane is firstly confirmed by various characterizations such as physicochemical properties, ion selectivity, and VRFB single-cell performance. Subsequently the optimum casting solvent is selected for the optimum DS SPEEK membrane within N,N‧-dimethylformamide (DMF), N,N‧-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and dimethylsulfoxide (DMSO). The different performance of SPEEK membranes prepared with various casting solvents can be attributed to the different interaction between solvent and -SO3H group of SPEEK. In the VRFB single-cell test, the optimum SPEEK membrane with DS of 67% and casting solvent of DMF (S67-DMF membrane) exhibits higher VRFB efficiencies and better cycle-life performance at 80 mA cm-2. The investigation of various DS and casting solvent will be effective guidance on the selection and modification of SPEEK membrane towards VRFB application.

Cosmic Ether

CERN Document Server

Tomaschitz, R

1998-01-01

A prerelativistic approach to particle dynamics is explored in an expanding Robertson-Walker cosmology. The receding galactic background provides a distinguished frame of reference and a unique cosmic time. In this context the relativistic, purely geometric space-time concept is criticized. Physical space is regarded as a permeable medium, the cosmic ether, which effects the world-lines of particles and rays. We study in detail a Robertson-Walker universe with linear expansion factor and negatively curved, open three-space; we choose the permeability tensor of the ether in such a way that the semiclassical approximation is exact. Galactic red-shifts depend on the refractive index of the ether. In the local Minkowskian limit the ether causes a time variation of mass, which scales inversely proportional to cosmic time. In the globally geodesic rest frames of galactic observers the ether manifests itself in an unbounded speed of signal transfer, in bifurcations of world-lines, and in time inversion effects.

Isolate PM1 populations are dominant and novel methyl tert-butyl ether-degrading bacterial in compost biofilter enrichments.

Science.gov (United States)

Bruns, M A; Hanson, J R; Mefford, J; Scow, K M

2001-03-01

The gasoline additive MTBE, methyl tert-butyl ether, is a widespread and persistent groundwater contaminant. MTBE undergoes rapid mineralization as the sole carbon and energy source of bacterial strain PM1, isolated from an enrichment culture of compost biofilter material. In this report, we describe the results of microbial community DNA profiling to assess the relative dominance of isolate PM1 and other bacterial strains cultured from the compost enrichment. Three polymerase chain reaction (PCR)-based profiling approaches were evaluated: denaturing gradient gel electrophoresis (DGGE) analysis of 230 bp 16S rDNA fragments; thermal gradient gel electrophoresis (TGGE) analysis of 575 bp 16S rDNA fragments; and non-denaturing polyacrylamide gel electrophoresis of 300-1,500 bp fragments containing 16S/23S ribosomal intergenic transcribed spacer (ITS) regions. Whereas all three DNA profiling approaches indicated that PM1-like bands predominated in mixtures from MTBE-grown enrichments, ITS profiling provided the most abundant and specific sequence data to confirm strain PM1's presence in the enrichment. Moreover, ITS profiling did not produce non-specific PCR products that were observed with T/DGGE. A further advantage of ITS community profiling over other methods requiring restriction digestion (e.g. terminal restriction fragment length polymorphisms) was that it did not require an additional digestion step or the use of automated sequencing equipment. ITS bands, excised from similar locations in profiles of the enrichment and PM1 pure culture, were 99.9% identical across 750 16S rDNA positions and 100% identical across 691 spacer positions. BLAST comparisons of nearly full-length 16S rDNA sequences showed 96% similarity between isolate PM1 and representatives of at least four different genera in the Leptothrix subgroup of the beta-Proteobacteria (Aquabacterium, Leptothrix, Rubrivivax and Ideonella). Maximum likelihood and parsimony analyses of 1,249 nucleotide

Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor

Energy Technology Data Exchange (ETDEWEB)

Ayyaru, Sivasankaran; Dharmalingam, Sangeetha, E-mail: sangeetha@annauniv.edu

2014-03-01

Graphical abstract: - Highlights: • Sulfonated poly ether ether ketone (SPEEK) membrane in SCMFC used to determine the BOD. • The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm. • This sensing range was 62.5% higher than that of Nafion{sup ®}. • SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}. • Nafion{sup ®} shows high anodic internal resistance (67 Ω) than the SPEEK (39 Ω). - Abstract: The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion{sup ®}. The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}, resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

Prolonged Hypocalcemic Effect by Pulmonary Delivery of Calcitonin Loaded Poly(Methyl Vinyl Ether Maleic Acid Bioadhesive Nanoparticles

Directory of Open Access Journals (Sweden)

J. Varshosaz

2014-01-01

Full Text Available The purpose of the present study was to design a pulmonary controlled release system of salmon calcitonin (sCT. Therefore, poly(methyl vinyl ether maleic acid [P(MVEMA] nanoparticles were prepared by ionic cross-linking method using Fe2+ and Zn2+ ions. Physicochemical properties of nanoparticles were studied in vitro. The stability of sCT in the optimized nanoparticles was studied by electrophoretic gel method. Plasma calcium levels until 48 h were determined in rats as pulmonary-free sCT solution or nanoparticles (25 μg·kg−1, iv solution of sCT (5 μg·kg−1, and pulmonary blank nanoparticles. The drug remained stable during fabrication and tests on nanoparticles. The optimized nanoparticles showed proper physicochemical properties. Normalized reduction of plasma calcium levels was at least 2.76 times higher in pulmonary sCT nanoparticles compared to free solution. The duration of hypocalcemic effect of pulmonary sCT nanoparticles was 24 h, while it was just 1 h for the iv solution. There was not any significant difference between normalized blood calcium levels reduction in pulmonary drug solution and iv injection. Pharmacological activity of nanoparticles after pulmonary delivery was 65% of the iv route. Pulmonary delivery of P(MVEMA nanoparticles of sCT enhanced and prolonged the hypocalcemic effect of the drug significantly.

Thermal and Optical Properties of New Poly(amide-imide)/Nanocomposite Reinforced by Layer Silicate Containing Diphenyl Ether Moieties

Science.gov (United States)

Faghihi, Khalil; Faramarzi, Ellahe; Shabanian, Meisam

2011-04-01

New poly(amide-imide)-montmorillonite reinforced nanocomposites containing Bis(4-N-trimellitylimido) diphenyl ether moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) 4 was synthesized by the direct polycondensation reaction of Bis(4-N-trimellitylimido) diphenyl ether 3 with 4,4'-diamino diphenyl ether 2 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nanocomposite films 4a and 4b with 10 and 20 mass% silicate particles respectively, were characterized by FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The properties of nanocomposites films were investigated by using Uv-vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements.

The preparation and intramolecular radical cyclisation reactions of chiral oxyme ethers

International Nuclear Information System (INIS)

Booth, Susan E.; Jenkins, Paul R.

1998-01-01

Chiral oxime ether 2 and Oxime ester 4 have been prepared by alkylation and esterification of the oxime 1. Racemic hydroxylamine 6 and chiral hydroxylamine 10 have been synthesised from N-hydroxysuccinimide and the corresponding alcohol in the presence of diethyl azo dicarboxylate, the two product were converted into the oxime ethers 7 and 11 respectively. The intramolecular radical cyclisation reactions of these oxime ethers and esters has been studied, successful reaction was observed to produce alkyl hydroxylamines 3,8 and 12. (author)

The Preparation and Intramolecular Radical Cyclisation Reactions of Chiral Oxime Ethers

Directory of Open Access Journals (Sweden)

Booth Susan E.

1998-01-01

Full Text Available Chiral oxime ether 2 and Oxime ester 4 have been prepared by alkylation and esterification of the oxime 1. Racemic hydroxylamine 6 and chiral hydroxylamine 10 have been synthesised from N-hydroxysuccinimide and the corresponding alcohol in the presence of diethylazodicarboxylate, the two products were converted into the oxime ethers 7 and 11 respectively. The intramolecular radical cyclisation reactions of these oxime ethers and esters has been studied, successful reaction was observed to produce alkyl hydroxylamines 3, 8 and 12.

Methyl-Analyzer--whole genome DNA methylation profiling.

Science.gov (United States)

Xin, Yurong; Ge, Yongchao; Haghighi, Fatemeh G

2011-08-15

Methyl-Analyzer is a python package that analyzes genome-wide DNA methylation data produced by the Methyl-MAPS (methylation mapping analysis by paired-end sequencing) method. Methyl-MAPS is an enzymatic-based method that uses both methylation-sensitive and -dependent enzymes covering >80% of CpG dinucleotides within mammalian genomes. It combines enzymatic-based approaches with high-throughput next-generation sequencing technology to provide whole genome DNA methylation profiles. Methyl-Analyzer processes and integrates sequencing reads from methylated and unmethylated compartments and estimates CpG methylation probabilities at single base resolution. Methyl-Analyzer is available at http://github.com/epigenomics/methylmaps. Sample dataset is available for download at http://epigenomicspub.columbia.edu/methylanalyzer_data.html. fgh3@columbia.edu Supplementary data are available at Bioinformatics online.

Diethyl Ether Production as a Substitute for Gasoline

Directory of Open Access Journals (Sweden)

Alviany Riza

2018-01-01

Full Text Available Diethyl ether is one of alternative fuel that could be used as a significant component of a blend or as a complete replacement for transportation fuel. The aim of this research is to produce diethyl ether through dehydration reaction of ethanol with fixed bed reactor using nanocrystalline γ-Al2O3 catalyst. Nanocrystalline γ-Al2O3 catalyst was synthesized by precipitation method using Al(NO33.9H2O as precursors and NH4OH as the precipitating agent. Dehydration reaction was performed at temperature range of 125 to 225°C. The result shows that synthesized γ-Al2O3 catalyst gave higher ethanol conversion and diethyl ether yield than that of commercial Al2O3 catalyst. The use of synthesized γ-Al2O3 catalyst could reach ethanol conversion as high as 94.71% and diethyl ether yield as high as 11,29%.

Gene mdpC plays a regulatory role in the methyl-tert-butyl ether degradation pathway of Methylibium petroleiphilum strain PM1.

Science.gov (United States)

Joshi, Geetika; Schmidt, Radomir; Scow, Kate M; Denison, Michael S; Hristova, Krassimira R

2015-04-01

Among the few bacteria known to utilize methyl tert-butyl ether (MTBE) as a sole carbon source, Methylibium petroleiphilum PM1 is a well-characterized organism with a sequenced genome; however, knowledge of the genetic regulation of its MTBE degradation pathway is limited. We investigated the role of a putative transcriptional activator gene, mdpC, in the induction of MTBE-degradation genes mdpA (encoding MTBE monooxygenase) and mdpJ (encoding tert-butyl alcohol hydroxylase) of strain PM1 in a gene-knockout mutant mdpC(-). We also utilized quantitative reverse transcriptase PCR assays targeting genes mdpA, mdpJ and mdpC to determine the effects of the mutation on transcription of these genes. Our results indicate that gene mdpC is involved in the induction of both mdpA and mdpJ in response to MTBE and tert-butyl alcohol (TBA) exposure in PM1. An additional independent mechanism may be involved in the induction of mdpJ in the presence of TBA. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Fabrication and properties of poly(polyethylene glycol n-alkyl ether vinyl ether)s as polymeric phase change materials

International Nuclear Information System (INIS)

Pei, Dong-fang; Chen, Sai; Li, Shu-qin; Shi, Hai-feng; Li, Wei; Li, Xuan; Zhang, Xing-xiang

2016-01-01

A series of poly(polyethylene glycol n-alkyl ether vinyl ether)s (PC m E n VEs) with various lengths of alkyl chains and polyethylene glycol spacers as side chain (m = 16,18; n = 1,2) were synthesized via two steps. First, monomers-ethylene glycol hexadecyl ether vinyl ether (C 16 E 1 VE), ethylene glycol octadecyl ether vinyl ether (C 18 E 1 VE), diethylene glycol hexadecyl ether vinyl ether (C 16 E 2 VE) and diethylene glycol octadecyl ether vinyl ether (C 18 E 2 VE) were synthesized by a modified Williamson etherification. Then, four new types of phase change materials were successfully fabricated by a living cationic polymerization. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) were employed to characterize their composition, thermal properties and crystallization behavior. The results show that, the side chains of PC 16 E 1 VE, PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are in a hexagonal lattice, and the onset temperatures for melting of PC 16 E 1 VE, PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are 39.8 °C, 37.4 °C, 51.0 °C and 48.9 °C, the onset temperatures for crystallization are 36.7 °C, 35.2 °C, 47.4 °C and 46.3 °C, respectively. The enthalpy changes of PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are higher than 100 J/g; on the contrary, it is 96 J/g for PC 16 E 1 VE. The enthalpy decrease is no more than 11% after 10 heating and cooling cycles. The 5 wt% mass loss temperatures of PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are higher than 300 °C; on the contrary, it’s 283 °C for PC 16 E 1 VE. Using a weak polarity, flexible alkyl ether chain (-OCH 2 CH 2 O-) as a spacer to link the main chain and side chain is conducive to the crystallization of the alkyl side chain. These new phase change materials can be applied in heat storage, energy conservation, and environmental protection.

Catabolism of methyl ter-butyl ether (MTBE): characterization of the enzymes of Mycobacterium austroafricanum IFP 2012 involved in MTBE degradation; Catabolisme du methyl tert-butyl ether (MTBE): caracterisation des enzymes impliquees dans la degradation du MTBE chez Mycobacterium austroafricanum IFP 2012

Energy Technology Data Exchange (ETDEWEB)

Lopes Ferreira, N

2005-11-15

Methyl tert-butyl ether (MTBE) is added to gasoline to meet the octane index requirement. its solubility in water and its poor biodegradability made the use of MTBE a great environmental concern, particularly regarding aquifers. We previously isolated M austroafricanum IFP 2012 able to use MTBE as a sole source of carbon and energy and the MTBE pathway was partially characterized. In the present study, which aimed at isolating the genes involved in MTBE biodegradation in order to use them for estimation of MTBE biodegradation capacities in contaminated environment, we isolated a new M. austroafricanum strain, IFP 2015. A new degradation intermediate, the 2-methyl 1,2-propane-diol (2-M1,2-PD), the product of tert-butanol (TBA) oxidation, was identified. We also determined the enzymes induced during growth of M. austroafricanum IFP 2012 on MTBF. Then, using the tools of protein analysis and of molecular biology, we isolated and cloned the mpd genes cluster in the plasmid pCL4D. Heterologous expression of the recombinant plasmid in M smegmatis tmc2 155, showed the involvement of an 2-M1,2-PD dehydrogenase (MpdB) and a hydroxy-iso-butyr-aldehyde dehydrogenase (MpdC), encoded by mpdB and mpdC, respectively. Both enzymes were responsible for the conversion of 2-M 1,2-PD to hydroxy-isobutyric acid (HIBA). A further survey of different M austroafricanum strains, including IFP 2012, IFP 2015 and JOBS (ex-M vaccae) showed the link between the ability to grow on C{sub 2} to C{sub 16} n-alkanes and the MTBE and TBA degradation capacities. The alkB gene was partially sequenced in all these strains. Expression of alkB was demonstrated in M. austroafricanum IFP 2012 after growth on propane, hexane, hexadecane and TBA. Finally, we identified 2-propanol as the intermediate of HIBA degradation. The gene encoding the 2-propanol:p-N,N'-dimethyl-4-nitroso-aniline (NDMA) oxidoreductase was detected M austroafricanum IFP 2012. (author)

Catabolism of methyl ter-butyl ether (MTBE): characterization of the enzymes of Mycobacterium austroafricanum IFP 2012 involved in MTBE degradation; Catabolisme du methyl tert-butyl ether (MTBE): caracterisation des enzymes impliquees dans la degradation du MTBE chez Mycobacterium austroafricanum IFP 2012

Energy Technology Data Exchange (ETDEWEB)

Lopes Ferreira, N.

2005-11-15

Methyl tert-butyl ether (MTBE) is added to gasoline to meet the octane index requirement. its solubility in water and its poor biodegradability made the use of MTBE a great environmental concern, particularly regarding aquifers. We previously isolated M austroafricanum IFP 2012 able to use MTBE as a sole source of carbon and energy and the MTBE pathway was partially characterized. In the present study, which aimed at isolating the genes involved in MTBE biodegradation in order to use them for estimation of MTBE biodegradation capacities in contaminated environment, we isolated a new M. austroafricanum strain, IFP 2015. A new degradation intermediate, the 2-methyl 1,2-propane-diol (2-M1,2-PD), the product of tert-butanol (TBA) oxidation, was identified. We also determined the enzymes induced during growth of M. austroafricanum IFP 2012 on MTBF. Then, using the tools of protein analysis and of molecular biology, we isolated and cloned the mpd genes cluster in the plasmid pCL4D. Heterologous expression of the recombinant plasmid in M smegmatis tmc2 155, showed the involvement of an 2-M1,2-PD dehydrogenase (MpdB) and a hydroxy-iso-butyr-aldehyde dehydrogenase (MpdC), encoded by mpdB and mpdC, respectively. Both enzymes were responsible for the conversion of 2-M 1,2-PD to hydroxy-isobutyric acid (HIBA). A further survey of different M austroafricanum strains, including IFP 2012, IFP 2015 and JOBS (ex-M vaccae) showed the link between the ability to grow on C{sub 2} to C{sub 16} n-alkanes and the MTBE and TBA degradation capacities. The alkB gene was partially sequenced in all these strains. Expression of alkB was demonstrated in M. austroafricanum IFP 2012 after growth on propane, hexane, hexadecane and TBA. Finally, we identified 2-propanol as the intermediate of HIBA degradation. The gene encoding the 2-propanol:p-N,N'-dimethyl-4-nitroso-aniline (NDMA) oxidoreductase was detected M austroafricanum IFP 2012. (author)

Misconceptions about the ether

International Nuclear Information System (INIS)

Duffy, M.C.

1980-01-01

Several misconceptions concerning the ether concept and ether models are reviewed and clarified so that the relationship between modern ether theory and orthodox relativity may be better understood. The question of the ether's supposed superfluidity as a concept, and its status in modern physics remains to be answered. (author)

Thermogravimetric analysis of the polymer acrylate-vinyl ether mixture cured by radiation

International Nuclear Information System (INIS)

Danu, Sugiarto

1998-01-01

An experiment on thermal stability of the polymer acrylate-vinyl ether mixture cured by radiation have been done using thermogravimetric analysis. Three kinds of acrylic oligomers i.e., epoxy acrylate, urethane acrylate, and polypropylene glycol diacrylate, and vinyl ether monomers i.e., triethylene glycol divinyl ether (DVE-3), 1,4-cyclohexane dimethanol divinyl ether (CHVE), and butanediol monovinyl ether (HBVE) were used in the experiment. Reaction was taken via radical and cationic polymerisation. In case of cationic polymerisation, diphenyliodonium hexafluorophosphate fotoinisiator was used in the formulation. Thermogravimetric analysis was conducted in a nitrogen atmosphere at a flow rate of 40 ml/minute with a constant heating rate 10 o C and evaluation range were done from 25 to 500 o C. The results of thermogravimetric analysis showed that acrylate and DVE-3 mixture produced the polymer films with higher thermal stability than the mixture of acrylate with CHVE or HBVE. The composition of acrylate-vinyl ether mixture and degree of unsaturation of vinyl ether monomers influenced the thermal stability of polymer. The mixture of epoxy acrylate-vinyl ether and polypropylene glycol diacrylate-vinyl ether have 1 initial decomposition temperature whereas the urethane acrylate-vinyl ether mixture has 2 initial decomposition temperatures. (authors)

Substantial production of drosophilin A methyl ether (tetrachloro-1,4-dimethoxybenzene) by the lignicolous basidiomycete Phellinus badius in the heartwood of mesquite ( Prosopis juliflora) trees

Science.gov (United States)

Garvie, Laurence A. J.; Wilkens, Barry; Groy, Thomas L.; Glaeser, Jessie A.

2015-04-01

Toxic organohalogen pollutants produced as by-products of industrial processes, such as chloroform and polychlorinated dibenzo- p-dioxins, also have significant natural sources. A substantial terrestrial source of halogenated organics originates from fungal decay of wood and leaf litter. Here we show that the lignicolous basidiomycete Phellinus badius deposits up to 30,000 mg of the halogenated metabolite drosophilin A methyl ether (DAME, tetrachloro-1,4-dimethoxybenzene) per kilogram of decayed heartwood in the mesquite Prosopis juliflora. DAME occurs as clusters of glassy crystals up to 1 mm long within the decayed heartwood. In addition, the Phellinus badius basidiocarps contain an average of 24,000 mg DAME/kg dried fruiting body, testifying to the significant translocation and accumulation of Cl accompanied by DAME biosynthesis. The high DAME concentrations attest to the substantial Cl content of the heartwood, which averages near 5,000 ppm, with Cl/K near 1:1, consistent with an inorganic chloride precursor. Phellinus badius has a circumglobal distribution in the tropics and subtropics, where it is widely distributed on hardwoods and commonly associated with decay of mesquite. There is the potential for extensive DAME formation within decayed heartwood worldwide given the extensive range of Phellinus badius and its propensity to form DAME within mesquites. Further, DAME production is not limited to Phellinus badius but occurs in a range of lignicolous basidiomycetes, suggesting a significant natural reservoir for this chloroaromatic with potential environmental implications.

Isolation and characterization of fatty acid methyl ester (FAME)-producing Streptomyces sp. S161 from sheep (Ovis aries) faeces.

Science.gov (United States)

Lu, Y; Wang, J; Deng, Z; Wu, H; Deng, Q; Tan, H; Cao, L

2013-09-01

An actinomycete producing oil-like mixtures was isolated and characterized. The strain was isolated from sheep faeces and identified as Streptomyces sp. S161 based on 16S rRNA gene sequence analysis. The strain showed cellulase and xylanase activities. The (1) H nuclear magnetic resonance (NMR) spectra of the mixtures showed that the mixtures were composed of fatty acid methyl esters (52·5), triglycerides (13·7) and monoglycerides (9·1) (mol.%). Based on the gas chromatography-mass spectrometry (GC-MS) analysis, the fatty acid methyl esters were mainly composed of C14-C16 long-chain fatty acids. The results indicated that Streptomyces sp. S161 could produce fatty acid methyl esters (FAME) directly from starch. To our knowledge, this is the first isolated strain that can produce biodiesel (FAME) directly from starch. © 2013 The Society for Applied Microbiology.

Sorption of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) to synthetic resins.

Science.gov (United States)

Bi, Erping; Haderlein, Stefan B; Schmidt, Torsten C

2005-10-01

Methyl tert-butyl ether (MTBE) is a widely used gasoline oxygenate. Contamination of MTBE and its major degradation product tert-butyl alcohol (TBA) in groundwater and surface water has received great attention. However, sorption affinity and sorption mechanisms of MTBE and TBA to synthetic resins, which can be potentially used in removal of these contaminants from water, in passive sampling, or in enrichment of bacteria, have not been studied systemically. In this study, kinetic and equilibrium sorption experiments (single solute and binary mixtures) on four synthetic resins were conducted. The sorption affinity of the investigated sorbents for MTBE and TBA decreases in the order Ambersorb 563>Optipore L493>Amberlite XAD4>Amberlite XAD7, and all show higher sorption affinity for MTBE than for TBA. Binary experiments with o-xylene, a major compound of gasoline as co-contaminant, imply that all resins preferentially sorb o-xylene over MTBE or TBA, i.e., there is sorption competition. In the equilibrium aqueous concentration (Ceq) range (0.1-139.0 mg/L for MTBE, and 0.01-48.4 mg/L for TBA), experimental and modeling results as well as sorbent characteristics indicate that micropore filling and/or some other type of adsorption process (e.g., adsorption to specific sites of high sorption potential at low concentrations) rather than partitioning were the dominant sorption mechanisms. Optipore L493 has favourable sorption and desorption characteristics, and is a suitable sorbent, e.g., in bacteria enrichment or passive sampling for moderately polar compounds. However, for highly polar compounds such as TBA, Ambersorb 563 might be a better choice, especially in water treatment.

The influence of propylene glycol ethers on base diesel properties and emissions from a diesel engine

International Nuclear Information System (INIS)

Gómez-Cuenca, F.; Gómez-Marín, M.; Folgueras-Díaz, M.B.

2013-01-01

Highlights: • Effect of propylene glycol ethers on diesel fuel properties. • Effect of these compounds on diesel engine performance and emissions. • Blends with ⩽4 wt.% of oxygen do not change substantially diesel fuel quality. • Blends with ⩽2.5 wt.% of oxygen reduce CO, HC and NOx emissions, but not smoke. • These compounds are helpful to reach a cleaner combustion in a diesel engine. - Abstract: The oxygenated additives propylene glycol methyl ether (PGME), propylene glycol ethyl ether (PGEE), dipropylene glycol methyl ether (DPGME) were studied to determine their influence on both the base diesel fuel properties and the exhaust emissions from a diesel engine (CO, NOx, unburnt hydrocarbons and smoke). For diesel blends with low oxygen content (⩽4.0 wt.%), the addition of these compounds to base diesel fuel decreases aromatic content, kinematic viscosity, cold filter plugging point and Conradson carbon residue. Also, each compound modifies the distillation curve at temperatures below the corresponding oxygenated compound boiling point, the distillate percentage being increased. The blend cetane number depends on the type of propylene glycol ether added, its molecular weight, and the oxygen content of the fuel. The addition of PGME decreased slightly diesel fuel cetane number, while PGEE and DPGME increased it. Base diesel fuel-propylene glycol ether blends with 1.0 and 2.5 wt.% oxygen contents were used in order to determine the performance of the diesel engine and its emissions at both full and medium loads and different engine speeds (1000, 2500 and 4000 rpm). In general, at full load and in comparison with base diesel fuel, the blends show a slight reduction of oxygen-free specific fuel consumption. CO emissions are reduced appreciably for 2.5 wt.% of oxygen blends, mainly for PGEE and DPGME. NOx emissions are reduced slightly, but not the smoke. Unburnt hydrocarbon emissions decrease at 1000 and 2500 rpm, but not at 4000 rpm. At medium load

Halogenated methyl-phenyl ethers (anisoles) in the environment: determination of vapor pressures, aqueous solubilities, Henry's law constants, and gas/water- (Kgw), n-octanol/water- (Kow) and gas/n-octanol (Kgo) partition coefficients.

Science.gov (United States)

Pfeifer, O; Lohmann, U; Ballschmiter, K

2001-11-01

Halogenated methyl-phenyl ethers (methoxybenzenes, anisoles) are ubiquitous organics in the environment although they are not produced in industrial quantities. Modelling the fate of organic pollutants such as halogenated anisoles requires a knowledge of the fundamental physico-chemical properties of these compounds. The isomer-specific separation and detection of 60 of the 134 possible congeners allowing an environmental fingerprinting are reported in this study. The vapor pressure p0(L) of more than 60 and further physico-chemical properties of 26 available congeners are given. Vapor pressures p0(L), water solubilities S(L)W, and n-octanol/water partition coefficients Kow were determined by capillary HR-GC (High Resolution Gas Chromatography) on a non-polar phase and by RP-HPLC (Reversed Phase High Performance Liquid Chromatography) on a C18 phase with chlorobenzenes as reference standards. From these experimental data the Henry's law constants H, and the gas/water Kgw and gas/n-octanol Kgo partition coefficients were calculated. We found that vapor pressures, water solubilities, and n-octanol/water partition coefficients of the halogenated anisoles are close to those of the chlorobenzenes. A similar environmental fate of both groups can, therefore, be predicted.

Health Risk Assessment for Inhalation Exposure to Methyl Tertiary Butyl Ether at Petrol Stations in Southern China.

Science.gov (United States)

Hu, Dalin; Yang, Jianping; Liu, Yungang; Zhang, Wenjuan; Peng, Xiaowu; Wei, Qinzhi; Yuan, Jianhui; Zhu, Zhiliang

2016-02-06

Methyl tertiary butyl ether (MTBE), a well known gasoline additive, is used in China nationwide to enhance the octane number of gasoline and reduce harmful exhaust emissions, yet little is known regarding the potential health risk associated with occupational exposure to MTBE in petrol stations. In this study, 97 petrol station attendants (PSAs) in southern China were recruited for an assessment of the health risk associated with inhalation exposure to MTBE. The personal exposure levels of MTBE were analyzed by Head Space Solid Phase Microextraction GC/MS, and the demographic characteristics of the PSAs were investigated. Cancer and non-cancer risks were calculated with the methods recommended by the United States Environmental Protection Agency. The results showed that the exposure levels of MTBE in operating workers were much higher than among support staff (p < 0.01) and both were lower than 50 ppm (an occupational threshold limit value). The calculated cancer risks (CRs) at the investigated petrol stations was 0.170 to 0.240 per 10⁶ for operating workers, and 0.026 to 0.049 per 10⁶ for support staff, which are below the typical target range for risk management of 1 × 10(-6) to 1 × 10(-4); The hazard quotients (HQs) for all subjects were <1. In conclusion, our study indicates that the MTBE exposure of PSAs in southern China is in a low range which does not seem to be a significant health risk.

Health Risk Assessment for Inhalation Exposure to Methyl Tertiary Butyl Ether at Petrol Stations in Southern China

Directory of Open Access Journals (Sweden)

Dalin Hu

2016-02-01

Full Text Available Methyl tertiary butyl ether (MTBE, a well known gasoline additive, is used in China nationwide to enhance the octane number of gasoline and reduce harmful exhaust emissions, yet  little is known regarding the potential health risk associated with occupational exposure to MTBE in petrol stations. In this study, 97 petrol station attendants (PSAs in southern China were recruited for an assessment of the health risk associated with inhalation exposure to MTBE. The personal exposure levels of MTBE were analyzed by Head Space Solid Phase Microextraction GC/MS, and the demographic characteristics of the PSAs were investigated. Cancer and non-cancer risks were calculated with the methods recommended by the United States Environmental Protection Agency. The results showed that the exposure levels of MTBE in operating workers were much higher than among support staff (p < 0.01 and both were lower than 50 ppm (an occupational threshold limit value. The calculated cancer risks (CRs at the investigated petrol stations was 0.170 to 0.240 per 106 for operating workers, and 0.026 to 0.049 per 106 for support staff, which are below the typical target range for risk management of 1 × 10−6 to 1 × 10−4; The hazard quotients (HQs for all subjects were <1. In conclusion, our study indicates that the MTBE exposure of PSAs in southern China is in a low range which does not seem to be a significant health risk.

Planck's constant and the three waves (TWs) of Einstein's covariant ether

Science.gov (United States)

Kostro, L.

1985-11-01

The implications of a three-wave model for elementary particles, satisfying the principles of both quantum mechanics and General Relativity (GR), are discussed. In GR, the ether is the fundamental source of all activity, where particles (waves) arise at singularities. Inertia and gravity are field properties of the ether. In flat regions of the space-time geodesic, wave excitations correspond to the presence of particles. A momentum-carrying excitation which occurs in the ether is a superluminal radiation (phase- or B-waves) which transports neither energy nor mass. Superposition of the B-waves produces soliton-like excitations on the ether to form C-waves, i.e., particles. The particle-waves travel through space-time on D-waves, and experience reflection, refraction and interference only where B-waves have interacted with the ether. The original particles, photons-maximons, existed at the Big Bang and had physical properties which are describable in terms of Planck's quantities.

Synthesis of some fenchyl-substituted alkenes and enol-ethers containing 3-oxyphenyl substituents by the Barton-Kellogg reaction

International Nuclear Information System (INIS)

Ciscato, Luiz Francisco M.L.; Bartoloni, Fernando H.; Baader, Wilhelm Josef; Bastos, Erick L.; Guenther, Wolfgang; Weiss, Dieter; Beckert, Rainer

2010-01-01

The synthesis of one fenchyl-substituted alkene and two enol-ethers, containing 3-oxyphenyl substituents by the Barton-Kellogg reaction is described. The tri-substituted aromatic fenchylalkene 1a was prepared in 53% yield from thiofenchone and a diazoanisole; whereas enol-ethers 1b and 1c were obtained (95 and 75% yield, respectively) using an inverse approach based on diazofenchone and aromatic thionoesters. A mixture of Z and E isomers was obtained in all cases; isomer attribution and quantification has been carried out by analysis of NMR spectroscopic data assisted by theoretical calculations (E/Z ratio: 1a = 0.72, 1b = 2.2, 1c = 1.8). Reaction proceeds with low stereoselectivity leading to the preferential formation of diastereoisomeric olefins and enol-ethers where the aromatic substituent resides at the side of the two fenchyl methyl groups. (author)

Synthesis of some fenchyl-substituted alkenes and enol-ethers containing 3-oxyphenyl substituents by the Barton-Kellogg reaction

Energy Technology Data Exchange (ETDEWEB)

Ciscato, Luiz Francisco M.L.; Bartoloni, Fernando H.; Baader, Wilhelm Josef, E-mail: wjbaader@iq.usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Fundamental; Bastos, Erick L. [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Guenther, Wolfgang; Weiss, Dieter; Beckert, Rainer [Friedrich-Schiller Universitaet Jena (Germany). Institut fuer Organische Chemie und Makromolekulare Chemie

2010-07-01

The synthesis of one fenchyl-substituted alkene and two enol-ethers, containing 3-oxyphenyl substituents by the Barton-Kellogg reaction is described. The tri-substituted aromatic fenchylalkene 1a was prepared in 53% yield from thiofenchone and a diazoanisole; whereas enol-ethers 1b and 1c were obtained (95 and 75% yield, respectively) using an inverse approach based on diazofenchone and aromatic thionoesters. A mixture of Z and E isomers was obtained in all cases; isomer attribution and quantification has been carried out by analysis of NMR spectroscopic data assisted by theoretical calculations (E/Z ratio: 1a = 0.72, 1b = 2.2, 1c = 1.8). Reaction proceeds with low stereoselectivity leading to the preferential formation of diastereoisomeric olefins and enol-ethers where the aromatic substituent resides at the side of the two fenchyl methyl groups. (author)

Reproductive toxicity of the glycol ethers.

Science.gov (United States)

Hardin, B D

1983-06-01

The glycol ethers are an important and widely used class of solvents. Recent studies have demonstrated that ethylene glycol monomethyl ether (EGME), ethylene glycol dimethyl ether (EGdiME), ethylene glycol monoethyl ether (EGEE), and ethylene glycol monoethyl ether acetate (EGEEA) are teratogenic. Other studies have demonstrated that testicular atrophy or infertility follow treatment of males with EGME, ethylene glycol monomethyl ether acetate (EGMEA), EGEE, EGEEA, diethylene glycol dimethyl ether (diEGdiME), and diethylene glycol monoethyl ether (diEGEE). Experimental data are reviewed and structure-activity relationships are speculated upon.

Emission Studies in CI Engine using LPG and Palm Kernel Methyl Ester as Fuels and Di-ethyl Ether as an Additive

Science.gov (United States)

Dora, Nagaraju; Jothi, T. J. Sarvoththama

2018-05-01

The present study investigates the effectiveness of using di-ethyl ether (DEE) as the fuel additive in engine performance and emissions. Experiments are carried out in a single cylinder four stroke diesel engine at constant speed. Two different fuels namely liquefied petroleum gas (LPG) and palm kernel methyl ester (PKME) are used as primary fuels with DEE as the fuel additive. LPG flow rates of 0.6 and 0.8 kg/h are considered, and flow rate of DEE is varied to maintain the constant engine speed. In case of PKME fuel, it is blended with diesel in the latter to the former ratio of 80:20, and DEE is varied in the volumetric proportion of 1 and 2%. Results indicate that for the engine operating in LPG-DEE mode at 0.6 kg/h of LPG, the brake thermal efficiency is lowered by 26%; however, NOx is subsequently reduced by around 30% compared to the engine running with only diesel fuel at 70% load. Similarly, results of PKME blended fuel showed a drastic reduction in the NOx and CO emissions. In these two modes of operation, DEE is observed to be significant fuel additive regarding emissions reduction.

Detection of experimentally produced acute pulmonary arterial occlusion by methyl iodide-131 inhalation imaging

International Nuclear Information System (INIS)

Grossman, Z.D.; McAfee, J.G.; Subramanian, G.

1981-01-01

Methyl iodide-131 (CH 3 I-131) is described as an agent for detection of acute experimentally produced pulmonary arterial occlusion in dogs. When gaseous CH 3 I-131 is inhaled, radioactivity passes instantaneously from the alveoli to the lung capillary bed. Where pulmonary blood flow exists, activity is washed out into the systemic circulation, but in areas of blood stasis, a transient pulmonary hot spot remains. CH 3 I-131 is easily produced and inexpensive, but administration is awkward and strict radiation safety precautions are mandatory

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

Science.gov (United States)

Kane, Staci R; Chakicherla, Anu Y; Chain, Patrick S G; Schmidt, Radomir; Shin, Maria W; Legler, Tina C; Scow, Kate M; Larimer, Frank W; Lucas, Susan M; Richardson, Paul M; Hristova, Krassimira R

2007-03-01

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(5) to C(12)) hydrocarbons present in petroleum products. Whole-genome analysis of PM1 revealed an approximately 4-Mb circular chromosome and an approximately 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 (approximately 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.

Biofiltration and inhibitory interactions of gaseous benzene, toluene, xylene, and methyl tert-butyl ether.

Science.gov (United States)

Shim, Eun-Hwa; Kim, Jaisoo; Cho, Kyung-Suk; Ryu, Hee Wook

2006-05-01

This study evaluated the individual and combined removal capacities of benzene, toluene, and xylene (B, T, and X) in the presence and absence of methyl tert-butyl ether (MTBE) in a polyurethane biofilter inoculated with a BTX-degrading microbial consortium, and further examined their interactive effects in various mixtures. In addition, Polymerase chain reaction-denaturing gradient gel electrophoresis and phylogenetic analysis of 16S rRNA gene sequences were used to compare the microbial community structures found in biofilters exposed to the various gases and gas mixtures. The maximum individual elimination capacities (MECs) of B, T, and X were 200, 238, and 400 g m(-3) h(-1), respectively. There was no significant elimination of MTBE alone. Addition of MTBE decreased the MECs of B,T, and X to 75, 100, and 300 g m(-3) h(-1), respectively, indicating that benzene was most strongly inhibited by MTBE. When the three gases were mixed (B + T + X), the removal capacities of individual B, T, and X were 50, 90, and 200 g m(-3) h(-1), respectively. These capacities decreased to 40, 50, and 100 g m(-3) h(-1) when MTBE was added to the mix. The MEC of the three-gas mixture (B + T + X) was 340 g m(-3) h(-1), and that of the four-gas mixture was 200 g m(-3) h(-1). Although MTBE alone was not degraded by the biofilter, it could be co-metabolically degraded in the presence of toluene, benzene, or xylene with the MECs of 34, 23, and 14 g m(-3) h(-1), respectively. The microbial community structure analysis revealed that two large groups could be distinguished based on the presence or absence of MTBE, and many of the dominant bacteria in the consortia were closely related to bacteria isolated from aromatic hydrocarbon-contaminated sites and/ or oil wastewaters. These findings provide important new insights into biofiltration and may be used to improve the rational design of biofilters for remediation of petroleum gas-contaminated airstreams according to composition types of mixed

Chemistry and phytotoxicity of thaxtomin A alkyl ethers.

Science.gov (United States)

Krasnoff, Stuart B; Lobkovsky, Emil B; Wach, Michael J; Loria, Rosemary; Gibson, Donna M

2005-11-30

The thaxtomin phytotoxins (1 and 2) from scab-producing Streptomyces pathogens of the potato are 2,5-dioxopiperazines consisting of modified l-tryptophanyl and l-phenylalanyl units. Thaxtomin A (1) is hydroxylated at C-14, the alpha carbon of the modified l-phenylalanyl moiety. Refluxing thaxtomin A in acidified MeOH, EtOH, and i-PrOH afforded C-14 thaxtomin A methyl- (3a and 3b), ethyl- (4a and 4b), and isopropyl- (5a and 5b) ethers, respectively, in both the 11S,14R (3a, 4a, and 5a) and 11S,14S (3b, 4b, and 5b) configurations. Crystal structures were determined for 3a and 4a. Extensive NMR as well as other spectroscopic data supported structural assignments for all of the derivatives. The 11S,14R-configured derivatives were slightly less potent than the natural products (1 and 2) as inhibitors of lettuce seedling root growth, whereas the activity of the 11S,14S epimers was much reduced, indicating that the configuration at C-14 found in the naturally occurring thaxtomins is essential for biological activity. Among the 11S,14R-configured compounds, potency decreased with an increasing size of the substituted alkoxy group.

Characterization of Microsolvated Crown Ethers from Broadband Rotational Spectroscopy

Science.gov (United States)

Perez, Cristobal; Schnell, Melanie; Blanco, Susana; Lopez, Juan Carlos

2016-06-01

Since they were first synthetized, crown ethers have been extensively used in organometallic chemistry due to their unparalleled binding selectivity with alkali metal cations. From a structural point of view, crown ethers are heterocycles containing oxygen and/or other heteroatoms, although the most common ones are formed from ethylene oxide unit. Crown ethers are conventionally seen as being hydrophilic inside and hydrophobic outside when the structures found for the metal cation complexes are considered. However, crown ethers are extremely flexible and in isolation may present a variety of stable conformations so that their structure may be easily adapted in presence of a strong ligand as an alkali metal cation minimize the energy of the resulting complex. Water can be considered a soft ligand which interacts with crown ethers through moderate hydrogen bonds. It is thus interesting to investigate which conformers are selected by water to form complexes, the preferred interaction sites and the possible conformational changes due to the presence of one or more water molecules. Previous studies identified microsolvated crown ethers but in all cases with a chromophore group attached to the structure. Here we present a broadband rotational spectroscopy study of microsolvated crown ethers produced in a pulsed molecular jet expansion. Several 1:1 and 1:2 crown ether:water aggregates are presented for 12-crown-4, 15-crown-5 and 18-crown-6. Unambiguous identification of the structures has been achieved using isotopic substitution within the water unit. The subtle changes induced in the structures of the crown ether monomer upon complexation and the hydrogen-bonding network that hold them together will be also discussed. F. Gámez, B. Martínez-Haya, S. Blanco,J. C. López and J. L. Alonso, Phys. Chem. Chem. Phys. 2014, 14 12912-12918 V. A. Shubert, C.W. Müller and T. Zwier, J. Phys. Chem. A 2009, 113 8067-8079

Radiation-grafting of 2-hydroxyethylmethacrylate and oligo (ethylene glycol) methyl ether methacrylate onto polypropylene films by one step method

Energy Technology Data Exchange (ETDEWEB)

Ramirez-Jimenez, Alejandro [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, Carmen; Concheiro, Angel [Departamento de Farmacia y Tecnologia Farmaceutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela (Spain); Bucio, Emilio, E-mail: ebucio@nucleares.unam.mx [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)

2012-01-15

Polypropylene films were modified with 2-hydroxyethylmethacrylate (HEMA) and oligo (ethylene glycol) methyl ether methacrylate (OEGMA) using the pre-irradiation method with gamma-rays (one step method). The effect of absorbed dose from 10 to 100 kGy, temperature (50, 60, and 70 {sup o}C), monomer concentration between 12.5% and 62.5%, monomers ratio from 10% to 90% and reaction time from 5 to 50 h; on the degree of grafting was determined. The grafted samples were analyzed by FTIR-ATR, TGA, DSC, swelling, and contact angle. Grafts onto polymeric films between 3% and 109% were obtained at doses from 10 to 100 kGy and a dose rate around 7.4 kGy/h. The graft percent increased with the content in HEMA in the HEMA:OEGMA feed mixture, which indicates a lower reactivity of OEGMA compared to HEMA. The hydrogel layer grafted on the polypropylene substrate increases the hydrophilicity of the surface and also provides certain temperature-responsiveness, which may be of interest for biomedical applications. - Highlights: > PP was grafted with a hydrogel layer applying the {gamma}-ray pre-irradiation method. > Effects of radiation dose, time, temperature and monomers concentration were evaluated. > Grafted layer increases the hydrophilicity of PP films. > HEMA and OEGMA grafted onto PP may be of interest for biomedical applications.

Theoretical calculation on a compound formed by methyl alcohol and simmondsin

Directory of Open Access Journals (Sweden)

İzzet KARA

2016-12-01

Full Text Available Etheric oil results from the esterification reactions of oil acids with alcohols. In these reactions, one molecule water (H2O is composed of H× protons from oil acids and OH- groups which separated from alcohol. Etheric oil is commonly used in food industry, perfume industry and medicine. From this perspective, we need to know physical properties of etheric oil as well as chemical properties. In this study, the highest occupied molecular orbital (HOMO energies, the lowest unoccupied molecular orbital (LUMO energies, the electronic properties (total energy, electronegativity, chemical hardness and softness, NBO analysis and thermodynamic parameters of a compound formed by methyl alcohol and simmondsin have been performed by using Gaussian 09W program. The structural and spectroscopic data of the molecule in the ground state have been calculated by using density functional method (DFT/B3LYP with the 6-31++G(d,p basis set.

Enhanced osteogenic activity of poly ether ether ketone using calcium plasma immersion ion implantation.

Science.gov (United States)

Lu, Tao; Qian, Shi; Meng, Fanhao; Ning, Congqin; Liu, Xuanyong

2016-06-01

As a promising implantable material, poly ether ether ketone (PEEK) possesses similar elastic modulus to that of cortical bones yet suffers from bio-inertness and poor osteogenic properties, which limits its application as orthopedic implants. In this work, calcium is introduced onto PEEK surface using calcium plasma immersion ion implantation (Ca-PIII). The results obtained from scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirm the modified layer with varying contents of calcium are formed on PEEK surfaces. Water contact angle measurements reveal the increasing hydrophobicity of both Ca-PIII treated surfaces. In vitro cell adhesion, viability assay, alkaline phosphatase activity and collagen secretion analyses disclose improved the adhesion, proliferation, and osteo-differentiation of rat bone mesenchymal stem cells (bMSCs) on Ca-PIII treated surfaces. The obtained results indicate that PEEK surface with enhanced osteogenic activity can be produced by calcium incorporation. Copyright © 2016 Elsevier B.V. All rights reserved.

Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite

DEFF Research Database (Denmark)

Rasmussen, Dominik Bjørn; Christensen, Jakob Munkholt; Temel, Burcin

2015-01-01

Unprecedented insight into the carbonylation of dimethyl ether over Mordenite is provided through the identification of ketene (CH2CO) as a reaction intermediate. The formation of ketene is predicted by detailed DFT calculations and verified experimentally by the observation of doubly deuterated ...

Exogenous ether lipids predominantly target mitochondria.

Directory of Open Access Journals (Sweden)

Lars Kuerschner

Full Text Available Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking.

Biosynthetic conversion of thebaine to codeinone. Mechanism of ketone formation from enol ether in vivo

International Nuclear Information System (INIS)

Horn, J.S.; Paul, A.G.; Rapoport, H.

1978-01-01

Biosynthesis of the morphinan alkaloids proceeds by conversion of the enol ether or thebaine to the keto group of neopinone and thence to codeinone. To determine the mechanism of this transformation, [G- 14 C,6- 18 O]thebaine was fed to Papaver somniferum and the codeine and morphine were isolated. Comparison of the 18 O/ 14 C ratios in the codeine and morphine isolated with that of the thebaine fed showed that approximately 34% of the 18 O had been retained. Parallel feedings with [G- 14 C,6- 18 O]-codeinone demonstrated that the loss was due to nonenzymic exchange. Thus, the mechanism of enol ether cleavage in thebaine is established as cleavage of the 6-O-methyl group with retention of the 6-oxygen in the codeinone

Ether formulations of relativity

International Nuclear Information System (INIS)

Duffy, M.C.

1980-01-01

Contemporary ether theories are surveyed and criticised, especially those formally identical to orthodox Relativity. The historical development of Relativity, Special and General, in terms of an ether, is briefly indicated. Classical interpretations of Generalized Relativity using ether are compared to Euclidean formulations using a background space. The history of a sub-group of theories, formulating a 'new' Relativity involving modified transforms, is outlined. According to the theory with which they agree, recent supposed detections of drift are classified and criticised. Cosmological evidence suggesting an ether is mentioned. Only ether theories formally identical to Relativity have been published in depth. They stand criticised as being contrary to the positivist spirit. The history of mechanical analogues is traced, from Hartley's representing gravitating matter as spherical standing waves, to recent suggestions that vortex-sponge might model electromagnetic, quantum, uncertainty and faster-than-light phenomena. Contemporary theories are particular physical theories, themselves 'second interpretations' of a primary mathematical model. Mechanical analogues are auxiliary, not necessary, to other theory, disclosing relationships between classical and non-classical descriptions of assemblies charging state. The ether-relativity polemic, part of a broader dispute about relativity, is founded on mistaken conceptions of the roles of mathematical and physical models, mechanical analogues; and a distored view of history, which indicates that ether theories have become relativistic. (author)

Continuous production of biodiesel under supercritical methyl acetate conditions: Experimental investigation and kinetic model.

Science.gov (United States)

Farobie, Obie; Matsumura, Yukihiko

2017-10-01

In this study, biodiesel production by using supercritical methyl acetate in a continuous flow reactor was investigated for the first time. The aim of this study was to elucidate the reaction kinetics of biodiesel production by using supercritical methyl. Experiments were conducted at various reaction temperatures (300-400°C), residence times (5-30min), oil-to-methyl acetate molar ratio of 1:40, and a fixed pressure of 20MPa. Reaction kinetics of biodiesel production with supercritical methyl acetate was determined. Finally, biodiesel yield obtained from this method was compared to that obtained with supercritical methanol, ethanol, and MTBE (methyl tertiary-butyl ether). The results showed that biodiesel yield with supercritical methyl acetate increased with temperature and time. The developed kinetic model was found to fit the experimental data well. The reactivity of supercritical methyl acetate was the lowest, followed by that of supercritical MTBE, ethanol, and methanol, under the same conditions. Copyright © 2017. Published by Elsevier Ltd.

Assessment of ether and alcohol fuels from coal. Volume 2. Technical report

Energy Technology Data Exchange (ETDEWEB)

1983-03-01

A unique route for the indirect liquefaction of coal to produce transportation fuel has been evaluated. The resultant fuel includes alkyl tertiary alkyl ethers and higher alcohols, all in the gasoline boiling range. When blended into gasoline, the ether fuel provides several advantages over the lower alcohols: (1) lower chemical oxygen content, (2) less-severe water-separation problems, and (3) reduced front-end volatility effects. The ether fuel also has high-octane quality. Further, it can be utilized as a gasoline substitute in all proportions. Production of ether fuel combines several steps, all of which are or have been practiced on an industrial scale: (1) coal gasification, (2) gas cleanup and shift to desired H/sub 2/:CO ratio, (3) conversion of synthesis gas to isobutanol, methanol, and higher alcohols, (4) separation of alcohols, (5) chemical dehydration of isobutanol to isobutylene, and (6) etherification of isobutylene with methanol. A pilot-plant investigation of the isobutanol synthesis step was performed. Estimates of ether-fuel manufacturing costs indicate this process route is significantly more costly than synthesis of methanol. However, the fuel performance features provide incentive for developing the necessary process and catalyst improvements. Co-production of higher-molecular-weight co-solvent alcohols represents a less-drastic form of methanol modification to achieve improvement in the performance of methanol-gasoline blends. Costs were estimated for producing several proportions of methanol plus higher alcohols from coal. Estimated fuel selling price increases regularly but modestly with higher alcohol content.

Improved surface hydrophilicity and antifouling property of polysulfone ultrafiltration membrane with poly(ethylene glycol) methyl ether methacrylate grafted graphene oxide nanofillers

Science.gov (United States)

Wang, Haidong; Lu, Xiaofei; Lu, Xinglin; Wang, Zhenghui; Ma, Jun; Wang, Panpan

2017-12-01

In this study, the GO-g-P(PEGMA) nanoplates were first synthesized by grafting hydrophilic poly (poly (ethylene glycol) methyl ether methacrylate) via surface-initiated atom transfer radical polymerization (SI-ATRP) method. A novel polysulfone (PSF) nanocomposite membrane using GO-g-P(PEGMA) nanoplates as nanofillers was fabricated. FTIR, TGA, 1H NMR, GPC and TEM were applied to verify the successful synthesis of the prepared nanoplates, while SEM, AFM, XPS, contact angle goniometry and filtration experiments were used to characterize the fabricated nanocomposite membranes. It was found that the new prepared nanofillers were well dispersed in organic PSF matrix, and the PSF/GO-g-P(PEGMA) nanocomposite membrane showed significant improvements in water flux and flux recovery rate. Based on the results of resistance-in-series model, the nanocomposite membrane exhibited superior resistance to the irreversible fouling. The excellent filtration and antifouling performance are attributed to the segregation of GO-g-P(PEMGA) nanofillers toward the membrane surface and the pore walls. Notably, the blended nanofillers appeared a stable retention in/on nanocomposite membrane after 30 days of washing time. The demonstrated method of synthesis GO-g-P(PEGMA) in this study can also be extended to preparation of other nanocomposite membrane in future.

Systemic effects of chronically administered methyl prednisolonate and methyl 17-deoxyprednisolonate.

Science.gov (United States)

Olejniczak, E; Lee, H J

1984-06-01

The systemic activities of methyl prednisolonate and methyl 17-deoxyprednisolonate (1) were studied in rats. Methyl 17-deoxyprednisolonate produced significant changes in the amount of sodium ion (decreased) and potassium ion (increased) in urine; however, methyl prednisolonate had no effect on electrolyte balance. Both methyl prednisolonate and methyl 17-deoxyprednisolonate had no effect on liver glycogen content, plasma corticosterone level and relative adrenal weight. In contrast, the parent compound prednisolone caused a significant decrease in liver glycogen content, plasma corticosterone level and relative adrenal weight.

Methyl-perfluoroheptene-ethers (CH3OC7F13): measured OH radical reaction rate coefficients for several isomers and enantiomers and their atmospheric lifetimes and global warming potentials.

Science.gov (United States)

Jubb, Aaron M; Gierczak, Tomasz; Baasandorj, Munkhbayar; Waterland, Robert L; Burkholder, James B

2014-05-06

Mixtures of methyl-perfluoroheptene-ethers (CH3OC7F13, MPHEs) are currently in use as replacements for perfluorinated alkanes (PFCs) and poly-ether heat transfer fluids, which are persistent greenhouse gases with lifetimes >1000 years. At present, the atmospheric processing and environmental impact from the use of MPHEs is unknown. In this work, rate coefficients at 296 K for the gas-phase reaction of the OH radical with six key isomers (including stereoisomers and enantiomers) of MPHEs used commercially were measured using a relative rate method. Rate coefficients for the six MPHE isomers ranged from ∼ 0.1 to 2.9 × 10(-12) cm(3) molecule(-1) s(-1) with a strong stereoisomer and -OCH3 group position dependence; the (E)-stereoisomers with the -OCH3 group in an α- position relative to the double bond had the greatest reactivity. Rate coefficients measured for the d3-MPHE isomer analogues showed decreased reactivity consistent with a minor contribution of H atom abstraction from the -OCH3 group to the overall reactivity. Estimated atmospheric lifetimes for the MPHE isomers range from days to months. Atmospheric lifetimes, radiative efficiencies, and global warming potentials for these short-lived MPHE isomers were estimated based on the measured OH rate coefficients along with measured and theoretically calculated MPHE infrared absorption spectra. Our results highlight the importance of quantifying the atmospheric impact of individual components in an isomeric mixture.

Rotation of methyl side groups in polymers: A Fourier transform approach to quasielastic neutron scattering. 1: Homopolymers

International Nuclear Information System (INIS)

Arrighi, V.; Higgins, J.S.; Howells, W.S.

1995-01-01

The rotational motion of the ester methyl group in poly(methyl methacrylate) (PMMA) was investigated using quasielastic neutron scattering (QENS). A comparison between the authors results and the QENS data reported in the literature for PMMA-d 5 indicates that the amount of quasielastic broadening is highly dependent upon the energy resolution of the spectrometer. This anomalous behavior is here attributed to the method of analysis, namely, the use of a single rotational frequency. Such a procedure leads to a non-Arrhenius temperature dependence, to a temperature-dependent elastic incoherent structure factor, and to values of rotational frequency which are resolution dependent. They propose an alternative approach to the analysis of the QENS data which accounts for the existence of a distribution of rotational frequencies. The frequency data are Fourier transformed to the time domain, and the intermediate scattering function is fitted using a stretched exponential or Kohlraush-Williams-Watts function. The excellent overlap between data from different spectrometers leaves no doubt on the adequacy of their procedure. Measurements of the ether methyl group rotation in poly(vinyl methyl ether) (PVME) are also reported. The PVME data confirm that the behavior observed for PMMA-d 5 is likely to be a common feature to all polymeric systems

Process for the production of methyl methacrylate

NARCIS (Netherlands)

Eastham, G.R.; Johnson, D.W.; Straathof, A.J.J.; Fraaije, Marco; Winter, Remko

2015-01-01

A process of producing methyl methacrylate or derivatives thereof is described. The process includes the steps of; (i) converting 2-butanone to methyl propionate using a Baeyer-Villiger monooxygenase, and (ii) treating the methyl propionate produced to obtain methyl methacrylate or derivatives

The Effect of Water Contaminated with Methyl Tertiary Butyl Ether (MTBE) on the Rat's Weight and Tissue

International Nuclear Information System (INIS)

Backer, Wadiah Saleh; AboKhatwa, Ahmed Nabil; Katouah, Hanadi Ahmed

2008-01-01

Lead is known to cause deleterious effects on health and environment. Therefore, it was removed from car-fuel, in the United States since 1979. In January 2001, Saudi Arabia and other Arabian Gulf States, replaced lead with a synthetic organic substance called methyl tertiary-butyl ether (MTBE). MTBE is added to gasoline at 12-15%. It dissolves readily in water and evaporates quickly. This study was focused on the possible health hazards of MTBE in drinking water as manifested by changes in weight and vital tissues (heart, liver, kidney, lung, and testis) of rat. This study also aimed to establish a quantitative relationship between MTBE concentration and changes that occur to these tissues. One hundred and twenty male Wistar rats were exposed to five different MTBE concentrations (0.0, 1,000, 1,500, 2,000, 2,500 ppm) for 60 days. The results showed that most of MTBE-treated animals have revealed significant weight loss and the maximum weight loss (nearly 10 %) was achieved at the highest concentration (2,500 ppm) after 60 days of treatment. Also, both liver and heart weights were significantly reduced by almost 9%, and kidneys by 8% of MTBE concentration of 2,000 ppm. At a higher concentration (2,500 ppm), liver weight was reduced by 12%. The weight of other tissues (lungs and testes) remained unchanged. The outcome of the results may lead to hepatic disorder. This disorder could reduce plasma glucose, or increase some hepatic markers like ALT, AST, and GGT activity, or elevate the levels of sodium and chloride in plasma and may have other side effects. (author)

Optimization of reactive simulated moving bed systems with modulation of feed concentration for production of glycol ether ester.

Science.gov (United States)

Agrawal, Gaurav; Oh, Jungmin; Sreedhar, Balamurali; Tie, Shan; Donaldson, Megan E; Frank, Timothy C; Schultz, Alfred K; Bommarius, Andreas S; Kawajiri, Yoshiaki

2014-09-19

In this article, we extend the simulated moving bed reactor (SMBR) mode of operation to the production of propylene glycol methyl ether acetate (DOWANOL™ PMA glycol ether) through the esterification of 1-methoxy-2-propanol (DOWANOL™ PM glycol ether) and acetic acid using AMBERLYST™ 15 as a catalyst and adsorbent. In addition, for the first time, we integrate the concept of modulation of the feed concentration (ModiCon) to SMBR operation. The performance of the conventional (constant feed) and ModiCon operation modes of SMBR are analyzed and compared. The SMBR processes are designed using a model based on a multi-objective optimization approach, where a transport dispersive model with a linear driving force for the adsorption rate has been used for modeling the SMBR system. The adsorption equilibrium and kinetics parameters are estimated from the batch and single column injection experiments by the inverse method. The multiple objectives are to maximize the production rate of DOWANOL™ PMA glycol ether, maximize the conversion of the esterification reaction and minimize the consumption of DOWANOL™ PM glycol ether which also acts as the desorbent in the chromatographic separation. It is shown that ModiCon achieves a higher productivity by 12-36% over the conventional operation with higher product purity and recovery. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessment of genotoxicity of methyl-tert-butyl ether, benzene, toluene, ethylbenzene, and xylene to human lymphocytes using comet assay

International Nuclear Information System (INIS)

Chen, Colin S.; Hseu, You C.; Liang, Shih H.; Kuo, J.-Y.; Chen, Ssu. C.

2008-01-01

Methyl-tert-butyl ether (MTBE) is a gasoline oxygenate and antiknock additive substituting for lead alkyls currently in use worldwide. Benzene, toluene, ethylbenzene, and xylene (BTEX) are volatile monoaromatic hydrocarbons which are commonly found together in crude petroleum and petroleum products such as gasoline. The aim of this study is to evaluate the genotoxic effects of these tested chemicals in human lymphocytes. Using the alkaline comet assay, we showed that all of the tested chemicals induce DNA damage in isolated human lymphocytes. This effect could follow from the induction of DNA strands breaks. The neutral version of the test revealed that MTBE, benzene, and xylenes induce DNA double-strand breaks at 200 μM. Apart from MTBE, the spin traps, 5,5-dimethyl-pyrroline-N-oxide (DMPO) and N-tert-butyl-α-phenylnitrone (PBN) can decrease the level of DNA damage in BTEX at 200 μM. This indicated that DNA damage could result from the participation of free radicals in DNA-damaging effect, which was further supported by the fact that post-treatment of formamidopyrimidine-DNA glycosylase (Fpg), enzyme recognizing oxidized DNA purines, gave rise to a significant increase in the extent of DNA damage in cells treated with benzene, and xylene at 200 μM. The results obtained suggested that MTBE and BTEX could induce a variety type of DNA damage such as single-strand breaks (SSBs), double-strand breaks (DSBs), and oxidative base modification

Rheological, mechanical and tribological properties of carbon-nanofibre reinforced poly (ether ether ketone composites

Directory of Open Access Journals (Sweden)

Volker Altstaedt

2003-12-01

Full Text Available Poly(ether ether ketone nanocomposites containing vapour-grown carbon nanofibres (CNF were produced using standard polymer processing techniques. At high shear rates no significant increase in resin viscosity was observed. Nevertheless, the addition of the CNFs results in a higher melt strength at 360°C. Electron microscopy confirmed the homogeneous dispersion and alignment of nanofibres in the polymer matrix. Evaluation of the mechanical composite properties revealed a linear increase in tensile stiffness and strength with nanofibre loading fractions up to 15 wt% whilst matrix ductility was maintained up to 10 wt%. An interpretation of the composite performance by short-fibre theory resulted in rather low intrinsic stiffness properties of the vapour-grown CNF. Differential scanning calorimetry was used to investigate crystallization kinetics and degree of crystallinity. The CNFs were found not to act as nucleating sites. Furthermore, unidirectional sliding tests against two different counterpart materials (100Cr6 martensitic bearing steel, X5CrNi18-10 austenitic stainless steel were performed. The carbon nanofibres were found to reduce the wear rate of PEEK significantly.

Metal ion separations with proton-ionizable Lariat Ethers and their polymers

International Nuclear Information System (INIS)

Bartsch, R.A.

1993-01-01

The preparation of novel and specific organic complexing agents may lead to the development of new separation systems for aqueous metal ions. Thus the introduction of highly lipophilic oximes led to the current utilization of these compounds as commercial extractants for the hydrometallurgy of nonferrous metals. Crown ethers (macrocyclic polyethers) have been employed in the laboratory-scale solvent extraction of alkali-metal, alkaline-earth, and other metal cations into organic phases. Attachment of side arms to crown ethers gives lariat ethers. The presence of one or more potential coordination sites in the side arm of the lariat ether may produce substantial changes in the selectivity and efficiency of metal ion complexation. It has been demonstrated that concomitant transfer of an aqueous phase anion into the organic medium is not required for metal ion extraction. This factor is of immense importance to potential practical applications of these proton-ionizable crown ethers in which the common, hard, aqueous phase anions would be involved. Another advantage of proton-ionizable lariat ethers is the ease with which extracted metal ions may be stripped from the organic phase by shaking with aqueous mineral acid. Thus both metal ion extraction and stripping are facilitated by pendent proton-ionizable groups. Most of the hazardous metal ion species in the Hanford Site tank wastes are members of the alkali-metal, alkaline-earth, lanthanide, and actinide families. These hard metal ion species prefer association with hard donor atoms, such as oxygens. Therefore, crown and lariat ethers are well-suited for complexation with such metal ion species

Effect of ethylene glycol monomethyl ether and diethylene glycol monomethyl ether on hepatic metabolizing enzymes.

Science.gov (United States)

Kawamoto, T; Matsuno, K; Kayama, F; Hirai, M; Arashidani, K; Yoshikawa, M; Kodama, Y

1990-06-01

Glycol ethers have been extensively used in industry over the past 40-50 years. Numerous studies on the toxicity of glycol ethers have been performed, however, the effects of glycol ethers on the hepatic drug metabolizing enzymes are still unknown. We studied the changes of the putative metabolic enzymes, that is, the hepatic microsomal mixed function oxidase system and cytosolic alcohol dehydrogenase, by the oral administration of diEGME and EGME. Adult male Wistar rats were used. DiEGME was administered orally; 500, 1000, 2000 mg/kg for 1, 2, 5 or 20 days and EGME was 100, 300 mg/kg for 1, 2, 5 or 20 days. Decreases in liver weights were produced by highest doses of diEGME (2000 mg/kg body wt/day for 20 days) and EGME (300 mg/kg body wt/day for 20 days). DiEGME increased hepatic microsomal protein contents and induced cytochrome P-450, but not cytochrome b5 or NADPH-cytochrome c reductase. The activity of cytosolic ADH was not affected by diEGME administration. On the other hand, EGME did not change cytochrome P-450, cytochrome b5 or NADPH-cytochrome c reductase. The activity of cytosolic ADH was increased by repeated EGME treatment. Therefore it is suspected that the enzyme which takes part in the metabolism of diEGME is different from that of EGME, although diEGME is a structural homologue of EGME.

Dimethyl ether production from methanol and/or syngas

Science.gov (United States)

Dagle, Robert A; Wang, Yong; Baker, Eddie G; Hu, Jianli

2015-02-17

Disclosed are methods for producing dimethyl ether (DME) from methanol and for producing DME directly from syngas, such as syngas from biomass. Also disclosed are apparatus for DME production. The disclosed processes generally function at higher temperatures with lower contact times and at lower pressures than conventional processes so as to produce higher DME yields than do conventional processes. Certain embodiments of the processes are carried out in reactors providing greater surface to volume ratios than the presently used DME reactors. Certain embodiments of the processes are carried out in systems comprising multiple microchannel reactors.

Ether the nothing that connects everything

CERN Document Server

Milutis, Joe

2006-01-01

In Ether, the histories of the unseen merge with discussions of the technology of electromagnetism. Navigating more than three hundred years of the ether''s cultural and artistic history, Joe Milutis reveals its continuous reinvention and tangible impact without ever losing sight of its ephemeral, elusive nature. The true meaning of ether, Milutis suggests, may be that it can never be fully grasped.

Usage of the word 'ether'

International Nuclear Information System (INIS)

Duffy, M.C.

1980-01-01

Confusion has been caused by scientists using the one word 'ether' to classify models differing from each other in important respects. Major roles assigned to the word are examined, and the nature of modern ether theories surveyed. The part played by the several meanings attached to the word, in the ether concept, is outlined. (author)

Evaluation of hepatic biotransformation of polybrominated diphenyl ethers in the polar bear (Ursus maritimus).

Science.gov (United States)

Krieger, Lisa K; Szeitz, András; Bandiera, Stelvio M

2016-03-01

Polar bears are at the top of the Arctic marine food chain and are subject to exposure and bioaccumulation of environmental chemicals of concern such as polybrominated diphenyl ethers (PBDEs), which were widely used as flame retardants. The aim of the present study was to evaluate the in vitro oxidative metabolism of 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) and 2,2',4,4',5-pentabrominated diphenyl ether (BDE-99) by polar bear liver microsomes. The identification and quantification of the hydroxy-brominated diphenyl ethers formed were assessed using an ultra-high performance liquid chromatography-tandem mass spectrometry-based method. Incubation of BDE-47 with archived individual liver microsomes, prepared from fifteen polar bears from northern Canada, produced a total of eleven hydroxylated metabolites, eight of which were identified using authentic standards. The major metabolites were 4'-hydroxy-2,2',4,5'-tetrabromodiphenyl ether and 5'-hydroxy-2,2',4,4'-tetrabromodiphenyl ether. Incubation of BDE-99 with polar bear liver microsomes produced a total of eleven hydroxylated metabolites, seven of which were identified using authentic standards. The major metabolites were 2,4,5-tribromophenol and 4-hydroxy-2,2',3,4',5-pentabromodiphenyl ether. Among the CYP specific antibodies tested, anti-rat CYP2B was found to be the most active in inhibiting the formation of hydroxylated metabolites of both BDE-47 and BDE-99, indicating that CYP2B was the major CYP enzyme involved in the oxidative biotransformation of these two congeners. Our study shows that polar bears are capable of forming multiple hydroxylated metabolites of BDE-47 and BDE-99 in vitro and demonstrates the role of CYP2B in the biotransformation and possibly in the toxicity of BDE-47 and BDE-99 in polar bears. Copyright © 2015 Elsevier Ltd. All rights reserved.

The failure of poly (ether ether ketone) in high speed contacts

Science.gov (United States)

Briscoe, B. J.; Stuart, B. H.; Sebastian, S.; Tweedale, P. J.

1993-04-01

The paper describes an experimental study, with an associated analysis incorporating supplementary data, of the anti-boundary lubricating action of an alkane-aliphatic carboxylic acid lubricant system in a poly (ether ether ketone)-mild steel contact. The experiments involve progressively increasing the load in a contact formed between a polymer plate and a rotating steel shaft and estimating the frictional work dissipated. Scuffing is identified when a rapid increase in frictional work is noted at a characteristic normal load. It is shown that the additive induces premature scuffing. Subsidiary data is provided using Raman spectroscopy and hardness probes, and confirms that certain additives such as decanoic acid and dodecylamine will induce surface plasticization in poly (ether ether ketone). The trends in the frictional data have been interpreted using the adhesive model of friction in conjunction with temperature-dependent interfacial theology and bulk mechanical property data. It is proposed that the scuffing process is induced prematurely as a consequence of excessive additive-induced subsurface plasticization. Restricted surface plasticization in this system provides an enhanced self-lubricating capacity.

Direct synthesis of ethanol from dimethyl ether and syngas over combined H-Mordenite and Cu/ZnO catalysts.

Science.gov (United States)

Li, Xingang; San, Xiaoguang; Zhang, Yi; Ichii, Takashi; Meng, Ming; Tan, Yisheng; Tsubaki, Noritatsu

2010-10-25

Ethanol was directly synthesized from dimethyl ether (DME) and syngas with the combined H-Mordenite and Cu/ZnO catalysts that were separately loaded in a dual-catalyst bed reactor. Methyl acetate (MA) was formed by DME carbonylation over the H-Mordenite catalyst. Thereafter, ethanol and methanol were produced by MA hydrogenation over the Cu/ZnO catalyst. With the reactant gas containing 1.0% DME, the optimized temperature for the reaction was at 493 K to reach 100% conversion. In the products, the yield of methanol and ethanol could reach 46.3% and 42.2%, respectively, with a small amount of MA, ethyl acetate, and CO(2). This process is environmentally friendly as the main byproduct methanol can be recycled to DME by a dehydration reaction. In contrast, for the physically mixed catalysts, the low conversion of DME and high selectivity of methanol were observed.

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

Science.gov (United States)

Kane, Staci R.; Chakicherla, Anu Y.; Chain, Patrick S. G.; Schmidt, Radomir; Shin, Maria W.; Legler, Tina C.; Scow, Kate M.; Larimer, Frank W.; Lucas, Susan M.; Richardson, Paul M.; Hristova, Krassimira R.

2007-01-01

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 (C5 to C12) hydrocarbons present in petroleum products. Whole-genome analysis of PM1 revealed an ∼4-Mb circular chromosome and an ∼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 (∼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. PMID:17158667

Dissociative Photoionization of Diethyl Ether.

Science.gov (United States)

Voronova, Krisztina; Mozaffari Easter, Chrissa M; Covert, Kyle J; Bodi, Andras; Hemberger, Patrick; Sztáray, Bálint

2015-10-29

The dissociative photoionization of internal energy selected diethyl ether ions was investigated by imaging photoelectron photoion coincidence spectroscopy. In a large, 5 eV energy range Et2O(+) cations decay by two parallel and three sequential dissociative photoionization channels, which can be modeled well using statistical theory. The 0 K appearance energies of the CH3CHOCH2CH3(+) (H-loss, m/z = 73) and CH3CH2O═CH2(+) (methyl-loss, m/z = 59) fragment ions were determined to be 10.419 ± 0.015 and 10.484 ± 0.008 eV, respectively. The reemergence of the hydrogen-loss ion above 11 eV is attributed to transition-state (TS) switching, in which the second, outer TS is rate-determining at high internal energies. At 11.81 ± 0.05 eV, a secondary fragment of the CH3CHOCH2CH3(+) (m/z = 73) ion, protonated acetaldehyde, CH3CH═OH(+) (m/z = 45) appears. On the basis of the known thermochemical onset of this fragment, a reverse barrier of 325 meV was found. Two more sequential dissociation reactions were examined, namely, ethylene and formaldehyde losses from the methyl-loss daughter ion. The 0 K appearance energies of 11.85 ± 0.07 and 12.20 ± 0.08 eV, respectively, indicate no reverse barrier in these processes. The statistical model of the dissociative photoionization can also be used to predict the fractional ion abundances in threshold photoionization at large temperatures, which could be of use in, for example, combustion diagnostics.

Effect of benzene and ethylbenzene on the transcription of methyl-tert-butyl ether degradation genes of Methylibium petroleiphilum PM1.

Science.gov (United States)

Joshi, Geetika; Schmidt, Radomir; Scow, Kate M; Denison, Michael S; Hristova, Krassimira R

2016-09-01

Methyl-tert-butyl ether (MTBE) and its degradation by-product, tert-butyl alcohol (TBA), are widespread contaminants detected frequently in groundwater in California. Since MTBE was used as a fuel oxygenate for almost two decades, leaking underground fuel storage tanks are an important source of contamination. Gasoline components such as BTEX (benzene, toluene, ethylbenzene and xylenes) are often present in mixtures with MTBE and TBA. Investigations of interactions between BTEX and MTBE degradation have not yielded consistent trends, and the molecular mechanisms of BTEX compounds' impact on MTBE degradation are not well understood. We investigated trends in transcription of biodegradation genes in the MTBE-degrading bacterium, Methylibium petroleiphilum PM1 upon exposure to MTBE, TBA, ethylbenzene and benzene as individual compounds or in mixtures. We designed real-time quantitative PCR assays to target functional genes of strain PM1 and provide evidence for induction of genes mdpA (MTBE monooxygenase), mdpJ (TBA hydroxylase) and bmoA (benzene monooxygenase) in response to MTBE, TBA and benzene, respectively. Delayed induction of mdpA and mdpJ transcription occurred with mixtures of benzene and MTBE or TBA, respectively. bmoA transcription was similar in the presence of MTBE or TBA with benzene as in their absence. Our results also indicate that ethylbenzene, previously proposed as an inhibitor of MTBE degradation in some bacteria, inhibits transcription of mdpA, mdpJ and bmoAgenes in strain PM1.

Chronic carcinogenicity study of gasoline vapor condensate (GVC) and GVC containing methyl tertiary-butyl ether in F344 rats.

Science.gov (United States)

Benson, Janet M; Gigliotti, Andrew P; March, Thomas H; Barr, Edward B; Tibbetts, Brad M; Skipper, Betty J; Clark, Charles R; Twerdok, Lorraine

2011-01-01

Chronic inhalation studies were conducted to compare the toxicity and potential carcinogenicity of evaporative emissions from unleaded gasoline (GVC) and gasoline containing the oxygenate methyl tertiary-butyl ether (MTBE; GMVC). The test materials were manufactured to mimic vapors people would be exposed to during refueling at gas stations. Fifty F344 rats per gender per exposure level per test article were exposed 6 h/d, 5 d/wk for 104 wk in whole body chambers. Target total vapor concentrations were 0, 2, 10, or 20 g/m³ for the control, low-, mid-, and high-level exposures, respectively. Endpoints included survival, body weights, clinical observations, organs weights, and histopathology. GVC and GMVC exerted no marked effects on survival or clinical observations and few effects on organ weights. Terminal body weights were reduced in all mid- and high-level GVC groups and high-level GMVC groups. The major proliferative lesions attributable to gasoline exposure with or without MTBE were renal tubule adenomas and carcinomas in male rats. GMV exposure led to elevated testicular mesothelioma incidence and an increased trend for thyroid carcinomas in males. GVMC inhalation caused an increased trend for testicular tumors with exposure concentration. Mid- and high-level exposures of GVC and GMVC led to elevated incidences of nasal respiratory epithelial degeneration. Overall, in these chronic studies conducted under identical conditions, the health effects in F344 rats following 2 yr of GVC or GMVC exposure were comparable in the production of renal adenomas and carcinomas in male rats and similar in other endpoints.

Chronic Carcinogenicity Study of Gasoline Vapor Condensate (GVC) and GVC Containing Methyl Tertiary-Butyl Ether in F344 Rats

Science.gov (United States)

Benson, Janet M.; Gigliotti, Andrew P.; March, Thomas H.; Barr, Edward B.; Tibbetts, Brad M.; Skipper, Betty J.; Clark, Charles R.; Twerdok, Lorraine

2011-01-01

Chronic inhalation studies were conducted to compare the toxicity and potential carcinogenicity of evaporative emissions from unleaded gasoline (GVC) and gasoline containing the oxygenate methyl tertiary-butyl ether (MTBE; GMVC). The test materials were manufactured to mimic vapors people would be exposed to during refueling at gas stations. Fifty F344 rats per gender per exposure level per test article were exposed 6 h/d, 5 d/wk for 104 wk in whole body chambers. Target total vapor concentrations were 0, 2, 10, or 20 g/m3 for the control, low-, mid-, and high-level exposures, respectively. Endpoints included survival, body weights, clinical observations, organs weights, and histopathology. GVC and GMVC exerted no marked effects on survival or clinical observations and few effects on organ weights. Terminal body weights were reduced in all mid- and high-level GVC groups and high-level GMVC groups. The major proliferative lesions attributable to gasoline exposure with or without MTBE were renal tubule adenomas and carcinomas in male rats. GMV exposure led to elevated testicular mesothelioma incidence and an increased trend for thyroid carcinomas in males. GVMC inhalation caused an increased trend for testicular tumors with exposure concentration. Mid- and high-level exposures of GVC and GMVC led to elevated incidences of nasal respiratory epithelial degeneration. Overall, in these chronic studies conducted under identical conditions, the health effects in F344 rats following 2 yr of GVC or GMVC exposure were comparable in the production of renal adenomas and carcinomas in male rats and similar in other endpoints. PMID:21432714

Single-Step Syngas-to-Distillates (S2D) Synthesis via Methanol and Dimethyl Ether Intermediates: Final Report

Energy Technology Data Exchange (ETDEWEB)

Dagle, Robert A.; Lebarbier, Vanessa MC; Lizarazo Adarme, Jair A.; King, David L.; Zhu, Yunhua; Gray, Michel J.; Jones, Susanne B.; Biddy, Mary J.; Hallen, Richard T.; Wang, Yong; White, James F.; Holladay, Johnathan E.; Palo, Daniel R.

2013-11-26

The objective of the work was to enhance price-competitive, synthesis gas (syngas)-based production of transportation fuels that are directly compatible with the existing vehicle fleet (i.e., vehicles fueled by gasoline, diesel, jet fuel, etc.). To accomplish this, modifications to the traditional methanol-to-gasoline (MTG) process were investigated. In this study, we investigated direct conversion of syngas to distillates using methanol and dimethyl ether intermediates. For this application, a Pd/ZnO/Al2O3 (PdZnAl) catalyst previously developed for methanol steam reforming was evaluated. The PdZnAl catalyst was shown to be far superior to a conventional copper-based methanol catalyst when operated at relatively high temperatures (i.e., >300°C), which is necessary for MTG-type applications. Catalytic performance was evaluated through parametric studies. Process conditions such as temperature, pressure, gas-hour-space velocity, and syngas feed ratio (i.e., hydrogen:carbon monoxide) were investigated. PdZnAl catalyst formulation also was optimized to maximize conversion and selectivity to methanol and dimethyl ether while suppressing methane formation. Thus, a PdZn/Al2O3 catalyst optimized for methanol and dimethyl ether formation was developed through combined catalytic material and process parameter exploration. However, even after compositional optimization, a significant amount of undesirable carbon dioxide was produced (formed via the water-gas-shift reaction), and some degree of methane formation could not be completely avoided. Pd/ZnO/Al2O3 used in combination with ZSM-5 was investigated for direct syngas-to-distillates conversion. High conversion was achieved as thermodynamic constraints are alleviated when methanol and dimethyl are intermediates for hydrocarbon formation. When methanol and/or dimethyl ether are products formed separately, equilibrium restrictions occur. Thermodynamic relaxation also enables the use of lower operating pressures than what

Environmental analysis of the life cycle emissions of 2-methyl tetrahydrofuran solvent manufactured from renewable resources.

Science.gov (United States)

Slater, C Stewart; Savelski, Mariano J; Hitchcock, David; Cavanagh, Eduardo J

2016-01-01

An environmental analysis has been conducted to determine the cradle to gate life cycle emissions to manufacture the green solvent, 2-methyl tetrahydrofuran. The solvent is considered a greener chemical since it can be manufactured from renewable resources with a lower life cycle footprint. Analyses have been performed using different methods to show greenness in both its production and industrial use. This solvent can potentially be substituted for other ether and chlorinated solvents commonly used in organometallic and biphasic reactions steps in pharmaceutical and fine chemical syntheses. The 2-methyl tetrahydrofuran made from renewable agricultural by-products is marketed by Penn A Kem under the name ecoMeTHF™. The starting material, 2-furfuraldehyde (furfural), is produced from corn cob waste by converting the available pentosans by acid hydrolysis. An evaluation of each step in the process was necessary to determine the overall life cycle and specific CO2 emissions for each raw material/intermediate produced. Allocation of credits for CO2 from the incineration of solvents made from renewable feedstocks significantly reduced the overall carbon footprint. Using this approach, the overall life cycle emissions for production of 1 kg of ecoMeTHF™ were determined to be 0.191 kg, including 0.150 kg of CO2. Life cycle emissions generated from raw material manufacture represents the majority of the overall environmental impact. Our evaluation shows that using 2-methyl tetrahydrofuran in an industrial scenario results in a 97% reduction in emissions, when compared to typically used solvents such as tetrahydrofuran, made through a conventional chemical route.

Uptake of polybrominated diphenyl ethers by carrot and lettuce crops grown in compost-amended soils.

Science.gov (United States)

Bizkarguenaga, E; Iparraguirre, A; Oliva, E; Quintana, J B; Rodil, R; Fernández, L A; Zuloaga, O; Prieto, A

2016-02-01

The uptake of polybrominated diphenyl ethers (PBDEs) by carrot and lettuce was investigated. Degradation of PBDEs in soil in the absence of the plants was discarded. Different carrot (Nantesa and Chantenay) and lettuce (Batavia Golden Spring and Summer Queen) varieties were grown in fortified or contaminated compost-amended soil mixtures under greenhouse conditions. After plant harvesting, roots (core and peel) and leaves were analyzed separately for carrot, while for lettuce, leaves and hearts were analyzed together. The corresponding bioconcentration factors (BCFs) were calculated. In carrots, a concentration gradient of 2,2',3,4,4',5'-hexabromodiphenyl ether (BDE-138) became evident that decreased from the root peel via root core to the leaves. For decabromodiphenyl ether (BDE-209) at the low concentration level (7 and 20 ng g(-1)), the leaves incorporated the highest concentration of the target substance. For lettuce, a decrease in the BCF value (from 0.24 to 0.02) was observed the higher the octanol-water partition coefficient, except in the case of BDE-183 (BCF = 0.51) and BDE-209 (BCF values from 0.41 to 0.74). Significant influence of the soils and crop varieties on the uptake could not be supported. Metabolic debromination, hydroxylation or methylation of the target PBDEs in the soil-plant system was not observed.

PREPARATION AND PROPERTIES OF THREE NEUTRAL COPPER (I COMPLEXES BASED ON BIS[2-(DIPHENYLPHOSPHINOPHENYL]ETHER PHENYL] ETHER AND SUBSTITUTED IMIDAZOLE-2,9-DIMETHYL-1,10-PHENANTHROLINE

Directory of Open Access Journals (Sweden)

Xin Fang Liu

2017-10-01

Full Text Available With deprotonated 2-(4-nitro phenyl-, 2-(4-methyl phenyl-, and 2-(4-methoxy phenyl imidazoled-2,9-dimethyl-1,10-phenanthroline (NPIP, MPIP and MoPIP as nitrogen ligands, as well as bis[2-(diphenylphosphino phenyl]ether (DPEphos as phosphorus ligand, three Cu(I neutral complex has been synthesized and characterized by infrared spectroscopy (IR, elemental analysis and 1H NMR methods. TG-DTA shows that the complex begins to decompose when the temperature reached about 220 oC, indicating their high thermo-stability. The emission spectrum shows that the complexes exhibit yellow emission with a peak emission wavelength of 576, 585 and 596 nm under excitation of 287 nm in powder state.

Silane Cross-Linked Sulfonted Poly(Ether Ketone/Ether Benzimidazoles for Fuel Cell Applications

Directory of Open Access Journals (Sweden)

Zilu Yao

2017-11-01

Full Text Available γ-(2,3-epoxypropoxy propyltrimethoxysilane (KH-560 was incorporated in various proportions into side-chain-type sulfonated poly(ether ketone/ether benzimidazole (SPEKEBI as a crosslinker, to make membranes with high ion exchange capacities and excellent performance for direct methanol fuel cells (DMFCs. Systematical measurements including Fourier transform infrared (FT-IR, scanning electron microscopy-energy-dispersive and X-ray photoelectron spectroscopy (XPS proved the complete disappearance of epoxy groups in KH-560 and the existence of Si in the membranes. The resulting membranes showed increased mechanical strength and thermal stability compared to the unmodified sulfonated poly(ether ketone/ether benzimidazole membrane in appropriate doping amount. Meanwhile, the methanol permeability has decreased, leading to the increase of relative selectivities of SPEKEBI-x-SiO2 membranes. Furthermore, the H2/O2 cell performance of SPEKEBI-2.5-SiO2 membrane showed a much higher peak power density compared with the pure SPEKEBI memrbrane.

Radiation-induced cationic curing of vinyl ethers

International Nuclear Information System (INIS)

Lapin, S.C.

1992-01-01

Recently there has been an increasing interest in nonacrylate radiation-curable coatings. Vinyl ethers are particularly reactive under cationic polymerization reaction conditions. The high efficiency of the photoacid initiators combined with the high reactivity of vinyl ether monomers makes this a potentially very useful system. This chapter discusses the preparation of vinyl ethers, introduces vinyl ether-functional monomers and oligomers, describes radiation-induced cationic polymerization of vinyl ethers, and discusses various coating systems. Throughout the chapter, an emphasis is placed on radiation-curable coating applications. 64 refs., 5 figs., 11 tabs

Photolytic degradation of polybromodiphenyl ethers under UV-lamp and solar irradiations

Energy Technology Data Exchange (ETDEWEB)

Shih, Yang-hsin, E-mail: yhs@nchu.edu.tw [Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 402, Taiwan (China); Wang, Chun-Kang [Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 402, Taiwan (China)

2009-06-15

Polybromodiphenyl ethers (PBDEs) are widely used flame retardant additives and have been mainly used in polymers for many plastic and electronic products. PBDEs have been found to bioaccumulate in both aquatic and terrestrial ecosystems and even human bodies. The technical product with the highest use is decabrominated diphenyl ether (BDE-209). Therefore, we chose to examine the solar and UV-lamp degradation of BDE-209. A linear increase of the photodegradation rate constant for BDE-209 was observed with the solar light intensity. The degradation reactions follow the pseudo-first-order kinetics. The photodegradation of BDE-209 produced other less brominated diphenyl ethers under ultraviolet light exposure, suggesting that the photodegradation of BDE-209 is a sequential dehalogenation mechanism. BDE-209 underwent rapid reductive debromination in these photodecomposition experiments. The formation rate constants of three nonabromodiphenyl ethers increase with the order of BDE-206, BDE-207 and BDE-208, indicating debromination mainly occurred at para > meta > ortho positions. These findings of the process properties and reductive debromination mechanism of the photolytic degradation of PBDEs can facilitate the design of remediation processes and also aid in predicting their fate in the environment.

Biology-oriented drug synthesis (BIODS) of 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl aryl ether derivatives, in vitro α-amylase inhibitory activity and in silico studies.

Science.gov (United States)

Taha, Muhammad; Imran, Syahrul; Ismail, Nor Hadiani; Selvaraj, Manikandan; Rahim, Fazal; Chigurupati, Sridevi; Ullah, Hayat; Khan, Fahad; Salar, Uzma; Javid, Muhammad Tariq; Vijayabalan, Shantini; Zaman, Khalid; Khan, Khalid Mohammed

2017-10-01

A new library of 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl aryl ether derivatives (1-23) were synthesized and characterized by EI-MS and 1 H NMR, and screened for their α-amylase inhibitory activity. Out of twenty-three derivatives, two molecules 19 (IC 50 =0.38±0.82µM) and 23 (IC 50 =1.66±0.14µM), showed excellent activity whereas the remaining compounds, except 10 and 17, showed good to moderate inhibition in the range of IC 50 =1.77-2.98µM when compared with the standard acarbose (IC 50 =1.66±0.1µM). A plausible structure-activity relationship has also been presented. In addition, in silico studies was carried out in order to rationalize the binding interaction of compounds with the active site of enzyme. Copyright © 2017 Elsevier Inc. All rights reserved.

Triclosan and Hydroxylated Polybrominated Diphenyl Ethers in Lake and Esturaine Sediments

Science.gov (United States)

Arnold, W. A.; Kerrigan, J. F.; McNeill, K.; Erickson, P. R.; Grandbois, M.

2014-12-01

Halogenated diphenyl ethers are a class of emerging contaminants that includes the antibacterial compound triclosan and the flame retardant polybrominated diphenyl ethers (PBDEs). Both triclosan and hydroxylated polybrominated diphenyl ethers (OH-BDEs) are known to form dioxins when exposed to sunlight in aqueous solution. Thus, it is important to understand the sources and presence of these compounds in the environment, especially because OH-BDEs are breakdown products of PBDEs and also naturally produced compounds. In this work, the levels of OH-BDEs were determined in lake sediments from Minnesota and esturaine sediments from San Francisco Bay. Both surface sediments over a broad spatial area and sediment cores were collected and analyzed. Triclosan was used as a marker of wastewater as a source of the targeted emerging contaminants. The relationship between triclosan and OH-BDE levels provides insight into the importance of natural and anthropogenic influences on the levels of OH-BDEs.

Novel Alkyd-Type Coating Resins Produced Using Cationic Polymerization [PowerPoint

Energy Technology Data Exchange (ETDEWEB)

Chisholm, Bret; Kalita, Harjyoti; Alam, Samim; Jayasooriyamu, Anurad; Fernando, Shashi; Samanata, Satyabrata; Bahr, James; Selvakumar, Sermadurai; Sibi, Mukund; Vold, Jessica; Ulven, Chad

2014-04-07

Novel, partially bio-based poly(vinyl ether) copolymers derived from soybean oil and cyclohexyl vinyl ether (CHVE) were produced by cationic polymerization and investigated for application as alkyd-type surface coatings. Compared to conventional alkyd resins, which are produced by high temperature melt condensation polymerization, the poly(vinyl ether)s provide several advantages. These advantages include miler, more energy efficient polymer synthesis, elimination of issues associated with gelation during polymer synthesis, production of polymers with well-defined composition and relatively narrow molecular weight distribution, and elimination of film formation and physical property issues associated with entrained monomers, dimers, trimmers, etc. The results of the studied showed that the thermal, mechanical, and physical properties of the coatings produced from these novel polymers varied considerable as a function of polymer composition and cure temperature. Overall, the results suggest a good potential for these novel copolymers to be used for coatings cured by autoxidation.

Densities and derived thermodynamic properties of the binary systems of 1,1-dimethylethyl methyl ether with allyl methacrylate, butyl methacrylate, methacrylic acid, and vinyl acetate at T = (298.15 and 308.15) K

International Nuclear Information System (INIS)

Wisniak, Jaime; Peralta, Rene D.; Infante, Ramiro; Cortez, Gladis

2005-01-01

Densities of the binary systems of 1,1-dimethylethyl methyl ether (MTBE) with allyl methacrylate, butyl methacrylate, methacrylic acid, and vinyl acetate have been measured as a function of the composition, at 298.15 and 308.15 K and atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess molar volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. The excess molar volumes are negative for the binaries of MTBE + methacrylates; the system MTBE with vinyl acetate presents near ideal behavior. The excess coefficient of thermal expansion is positive for all the systems studied here; the value of the coefficient for the system MTBE + allyl methacrylate is at least three times larger than that for the other systems

Poly (ether ether ketone) membranes for fuel cells

International Nuclear Information System (INIS)

Marrero, Jacqueline C.; Gomes, Ailton de S.; Filho, Jose C.D.; Hui, Wang S.; Oliveira, Vivianna S. de

2015-01-01

Polymeric membranes were developed using a SPEEK polymer matrix (sulphonated poly (ether ether ketone)), containing hygroscopic particles of zirconia (Zr) (incorporated by sol-gel method), for use as electrolyte membranes in fuel cells. SPEEK with different sulfonation degrees were used: 63 and 86%. The thermal analysis (TGA and DSC) was carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS) was carried out to evaluating the proton conductivity of the membranes. Additional analysis were underway in order to characterize these membranes, which include: X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to evaluate the influence of zirconia and sulfonation degree on the properties of the membranes. (author)

Ion-Selective Ionic Polymer Metal Composite (IPMC) actuator based on crown ether containing sulfonated Poly(Arylene Ether Ketone)

NARCIS (Netherlands)

Tas, S.; Zoetebier, B.; Sukas, O.S.; Bayraktar, M.; Hempenius, M.; Vancso, G.J.; Nijmeijer, K.

2017-01-01

This study introduces the concept of ion selective actuation in polymer metal composite actuators, employing crown ether bearing aromatic polyether materials. For this purpose, sulfonated poly(arylene ether ketone) (SPAEK) and crown ether containing SPAEK with molar masses suitable for membrane

All solid supercapacitor based on polyaniline and crosslinked sulfonated poly[ether ether ketone

International Nuclear Information System (INIS)

Sivaraman, P.; Kushwaha, R.K.; Shashidhara, K.; Hande, V.R.; Thakur, A.P.; Samui, A.B.; Khandpekar, M.M.

2010-01-01

All solid supercapacitor based on polyaniline (PANI) and crosslinked sulfonated poly[ether ether ketone] (XSPEEK,) is reported in this paper. The crosslinker used for sulfonated poly[ether ether ketone] (SPEEK) is 1,4-bis(hydroxymethyl) benzene. The XSPEEK is used as both solid electrolyte and separator membrane. Supercapacitors are fabricated using various PANI/XSPEEK weight ratios. These are characterized by cyclic voltammetry and galvanostatic charge-discharge studies. The supercapacitor with PANI/XSPEEK weight ratio 1:0.5, exhibit a specific capacitance of 480 F g -1 of PANI. To the best of authors' knowledge, the value reported here is the highest for a supercapacitor based on a proton conducting solid polymer electrolyte and PANI. Detailed electrochemical impedance spectroscopy analysis is carried out. The analysis shows that the complex capacitance of the supercapacitor depends on the XSPEEK content. The time constant (t 0 ), derived from the imaginary part of complex capacitance decreases with increase in the XSPEEK content in the supercapacitor. Cycle life characteristics of the supercapacitor show a decrease in specific capacitance during initial cycles and get stabilized during later cycles.

Deriving Biomonitoring Equivalents for selected E- and P-series glycol ethers for public health risk assessment.

Science.gov (United States)

Poet, Torka; Ball, Nicholas; Hays, Sean M

2016-01-01

Glycol ethers are a widely used class of solvents that may lead to both workplace and general population exposures. Biomonitoring studies are available that have quantified glycol ethers or their metabolites in blood and/or urine amongst exposed populations. These biomonitoring levels indicate exposures to the glycol ethers, but do not by themselves indicate a health hazard risk. Biomonitoring Equivalents (BEs) have been created to provide the ability to interpret human biomonitoring data in a public health risk context. The BE is defined as the concentration of a chemical or metabolite in a biological fluid (blood or urine) that is consistent with exposures at a regulatory derived safe exposure limit, such as a tolerable daily intake (TDI). In this exercise, we derived BEs for general population exposures for selected E- and P-series glycol ethers based on their respective derived no effect levels (DNELs). Selected DNELs have been derived as part of respective Registration, Evaluation, Authorisation and Regulation of Chemicals (REACh) regulation dossiers in the EU. The BEs derived here are unique in the sense that they are the first BEs derived for urinary excretion of compounds following inhalation exposures. The urinary mass excretion fractions (Fue) of the acetic acid metabolites for the E-series GEs range from approximately 0.2 to 0.7. The Fues for the excretion of the parent P-series GEs range from approximately 0.1 to 0.2, with the exception of propylene glycol methyl ether and its acetate (Fue = 0.004). Despite the narrow range of Fues, the BEs exhibit a larger range, resulting from the larger range in DNELs across GEs. The BEs derived here can be used to interpret human biomonitoring data for inhalation exposures to GEs amongst the general population. Copyright © 2015 Elsevier GmbH. All rights reserved.

Hydrogen storage by functionalised Poly(ether ether ketone)

Energy Technology Data Exchange (ETDEWEB)

Pedicini, R.; Giacoppo, G.; Carbone, A.; Passalacqua, E. [CNR-ITAE, Messina (Italy). Inst. for Advanced Energy Technologies

2010-07-01

In this work a functionalised polymer was studied as potential material for hydrogen storage in solid state. A Poly(ether ether ketone) (PEEK) matrix was modified by a manganese oxide in situ formation. Here we report the functionalisation process and the preliminary results on hydrogen storage capability of the synthesised polymer. The polymer was characterized by Scanning Electron Microscopy, X-ray diffraction, Transmission Electron Microscopy and Gravimetric Hydrogen Adsorption measurements. In the functionalised PEEK, morphological changes occur as a function of oxide precursor concentration and reaction time. Promising results by gravimetric measurements were obtained with a hydrogen sorption of 0.24%wt/wt at 50 C and 60 bar, moreover, reversibility hydrogen adsorption and desorption in a wide range of both temperature and pressure was confirmed. (orig.)

Poly-ethers from Winogradskyella poriferorum: Antifouling potential, time-course study of production and natural abundance

KAUST Repository

Dash, Swagatika

2011-08-01

A sponge-associated bacterium, Winogradskyella poriferorum strain UST030701-295T was cultured up to 100l for extraction of antifouling bioactive compounds. Five poly-ethers were isolated and partially characterized based on nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS); two of them showed inhibitory effects on biofilm formation of marine bacteria and larval settlement of macro-foulers but did not produce any adverse effects on the phenotypes of zebra fish embryos at a concentration of 5μgml -1. The effect of culture duration on the production of the poly-ethers and the bioactivity of the relevant extracts was monitored over a period of 12days. The total crude poly-ether production increased from day 2 to day 5 and the highest bioactivity was observed on day 3. The poly-ethers were found to be localized in the cellular fraction of the extracts, implying their natural occurrence. The potent bioactivity of these poly-ethers together with their high natural abundance in bacteria makes them promising candidates as ingredients in antifouling applications. © 2011 Elsevier Ltd.

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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.

A subchronic dermal exposure study of diethylene glycol monomethyl ether and ethylene glycol monomethyl ether in the male guinea pig.

Science.gov (United States)

Hobson, D W; D'Addario, A P; Bruner, R H; Uddin, D E

1986-02-01

Diethylene glycol monomethyl ether (DEGME) has been selected as a replacement anti-icing additive for ethylene glycol monomethyl ether (EGME) in Navy jet aircraft fuel. This experiment was performed to determine whether DEGME produced similar toxicity to EGME following dermal exposure. Male guinea pigs were dermally exposed to 1.00, 0.20, 0.04, or 0 (control) g/kg/day DEGME for 13 weeks, 5 days/week, 6 hr/day. Another group of animals was similarly exposed to 1.00 g/kg/day EGME. Body weights as well as testicular and splenic weights were reduced as a result of exposure to EGME, DEGME-exposed animals exhibited decreased splenic weight in the high- and medium-dose (1.00 and 0.20 g/kg/day) exposure groups only. Hematologic changes in EGME-exposed animals included mild anemia with increased erythrocytic mean corpuscular volumes and a lymphopenia with increased neutrophils. Similar hematological changes were not observed in any animals exposed to DEGME. Serum creatine kinase activity was increased in animals exposed to EGME, and serum lactate dehydrogenase activity was increased in EGME and 1.00 g/kg/day DEGME-exposed animals. In general, DEGME produced minimal toxicological changes following dermal exposure, whereas the toxicological changes observed following similar exposure to EGME were much more profound.

Activity relationships for aromatic crown ethers

International Nuclear Information System (INIS)

Wilson, Mark James

1998-01-01

This thesis involves an investigation of aromatic crown ethers and a study of their binding constants for alkali metals. The study was motivated by the current needs of the semiconductor industry to improve the scavenging of mobile ions from fabricated circuits. A number of aromatic crown ethers have been sulphonated in an attempt to improve their water solubility and cation binding activity. These materials have been extensively studied and their binding activity determined. In collaboration with a molecular modelling study, the effect of ionisable sulphonate groups on the macrocycles' behaviour has been investigated. The broader issue of the effect of substituents in aromatic crown ethers has also been studied with the preparation of a wide range of substituted crown ethers. The cation binding activity of these materials has been found to bear a simple relationship to the electron withdrawing nature of the aromatic substituents. This relationship can be accurately monitored using electronic charge densities from molecular modelling and this rational has been applied to the study of proton ionisable and lariating crown ethers. The incorporation of crown ethers into polyamic acid and polyimide frameworks has also been investigated, where the resulting materials have been found to exhibit unusual cation binding and uptake properties. These results imply that the combination of the crown ethers' macrocycle and adjacent carboxylic acid residues, from the polyamic acids, are conducive to effective cationic binding. NMR measurements, in conjunction with molecular modelling, have been used to explore the geometry changes encountered as the crown ether goes from it's uncomplexed to its complexed state. The energy requirement for these geometry changes has subsequently been used to examine the cation selectivity of these materials. The electronic charge changes associated with the complexation have also been investigated and correlated with the theoretical results. (author)

γ-aminobutyric acidA (GABAA) receptor regulates ERK1/2 phosphorylation in rat hippocampus in high doses of Methyl Tert-Butyl Ether (MTBE)-induced impairment of spatial memory

International Nuclear Information System (INIS)

Zheng Gang; Zhang Wenbin; Zhang Yun; Chen Yaoming; Liu Mingchao; Yao Ting; Yang Yanxia; Zhao Fang; Li Jingxia; Huang Chuanshu; Luo Wenjing; Chen Jingyuan

2009-01-01

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 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 A receptor α1 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 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.

Biaxial deformation behaviour of poly-ether-ether-ketone

Science.gov (United States)

Turner, Josh; Menary, Gary; Martin, Peter

2018-05-01

The biaxial tensile properties of thin poly-ether-ether-ketone (PEEK) films are presented. Investigation into the biaxial mechanical behaviour of PEEK films will provide a preliminary insight into the anticipated stress/strain response, and potential suitability, to the possible fabrication of thin walled parts through stretch blow moulding and thermoforming processes - with the multi-axial state of strain imposed onto the heated thermoplastic sheet representative of the expected strain history experienced during these material forming processes. Following identification of the prospective forming temperature window, the biaxial mechanical behaviour of the material is characterized under differing modes of deformation, at a nominal strain rate of 1 s-1. The temperature dependence is outlined within - with an appreciable increase in flow behaviour correlated with specimen temperature exceeding its glass transition temperature (Tg).

Surface-Initiated Atom Transfer Radical Polymerization of Magnetite Nanoparticles with Statistical Poly(tert-butyl acrylate-poly(poly(ethylene glycol methyl ether methacrylate Copolymers

Directory of Open Access Journals (Sweden)

Patcharin Kanhakeaw

2015-01-01

Full Text Available This work presented the surface modification of magnetite nanoparticle (MNP with poly[(t-butyl acrylate-stat-(poly(ethylene glycol methyl ether methacrylate] copolymers (P[(t-BA-stat-PEGMA] via a surface-initiated “grafting from” atom transfer radical polymerization (ATRP. Loading molar ratio of t-BA to PEGMA was systematically varied (100 : 0, 75 : 25, 50 : 50, and 25 : 75, resp. such that the degree of hydrophilicity of the copolymers, affecting the particle dispersibility in water, can be fine-tuned. The reaction progress in each step of the synthesis was monitored via Fourier transform infrared spectroscopy (FTIR. The studies in the reaction kinetics indicated that PEGMA had higher reactivity than that of t-BA in the copolymerizations. Gel permeation chromatography (GPC indicated that the molecular weights of the copolymers increased with the increase of the monomer conversion. Transmission electron microscopy (TEM revealed that the particles were spherical with averaged size of 8.1 nm in diameter. Dispersibility of the particles in water was apparently improved when the copolymers were coated as compared to P(t-BA homopolymer coating. The percentages of MNP and the copolymer in the composites were determined via thermogravimetric analysis (TGA and their magnetic properties were investigated via vibrating sample magnetometry (VSM.

Novel crosslinked membranes based on sulfonated poly(ether ether ketone) for direct methanol fuel cells.

Science.gov (United States)

Zhu, Yuanqin; Zieren, Shelley; Manthiram, Arumugam

2011-07-14

Novel covalently crosslinked membranes based on sulfonated poly(ether ether ketone) and carboxylated polysulfone exhibit much lower methanol crossover and better performance in direct methanol fuel cells at 65 °C in 1 and 2 M methanol solutions compared to Nafion 115 membranes.

Preparation and Characterization of Sulfonated Poly (ether ether ...

African Journals Online (AJOL)

NJD

2007-08-10

Aug 10, 2007 ... Preparation and Characterization of Sulfonated Poly (ether ... Currently perfluori- ... with phosphoric acid solution according to the method described earlier.11,12 ... where A is the membrane area available for diffusion; CA is.

Lithiated and sulphonated poly(ether ether ketone) solid state electrolyte films for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Chiu, K.-F.; Su, S.-H., E-mail: minimono42@gmail.com

2013-10-01

Poly(ether ether ketone) (PEEK) films have been synthesised and used as solid-state electrolytes for supercapacitors. In order to increase their ion conductivity, the PEEK films were sulphonated by sulphuric acid, and various amounts of LiClO{sub 4} were added. The solid-state electrolyte films were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The ionic conductivities of the electrolyte films were analysed by performing electrochemical impedance spectroscopy. The obtained electrolyte films can be sandwiched or directly coated on activated carbon electrodes to form solid-state supercapacitors. The electrochemical characteristics of these supercapacitors were investigated by performing cyclic voltammetry and charge–discharge tests. Under an optimal content of LiClO{sub 4}, the supercapacitor can provide a capacitance as high as 190 F/g. After 1000 cycles, the supercapacitors show almost no capacitance fading, indicating high stability of the solid-state electrolyte films. - Highlights: • Poly(ether ether ketone) (PEEK) films have been used as solid-state electrolytes. • LiClO4 addition can efficiently improve the ionic conductivity. • Supercapacitors using PEEK electrolyte films deliver high capacitance.

Lithiated and sulphonated poly(ether ether ketone) solid state electrolyte films for supercapacitors

International Nuclear Information System (INIS)

Chiu, K.-F.; Su, S.-H.

2013-01-01

Poly(ether ether ketone) (PEEK) films have been synthesised and used as solid-state electrolytes for supercapacitors. In order to increase their ion conductivity, the PEEK films were sulphonated by sulphuric acid, and various amounts of LiClO 4 were added. The solid-state electrolyte films were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The ionic conductivities of the electrolyte films were analysed by performing electrochemical impedance spectroscopy. The obtained electrolyte films can be sandwiched or directly coated on activated carbon electrodes to form solid-state supercapacitors. The electrochemical characteristics of these supercapacitors were investigated by performing cyclic voltammetry and charge–discharge tests. Under an optimal content of LiClO 4 , the supercapacitor can provide a capacitance as high as 190 F/g. After 1000 cycles, the supercapacitors show almost no capacitance fading, indicating high stability of the solid-state electrolyte films. - Highlights: • Poly(ether ether ketone) (PEEK) films have been used as solid-state electrolytes. • LiClO4 addition can efficiently improve the ionic conductivity. • Supercapacitors using PEEK electrolyte films deliver high capacitance

Hardness and wear properties of boron-implanted poly(ether-ether-ketone) and poly-ether-imide

International Nuclear Information System (INIS)

Lee Youngchul; Lee, E.H.; Mansur, L.K.

1992-01-01

The effects of boron beam irradiation on the hardness, friction, and wear of polymer surfaces were investigated. Typical high-performance thermoplastics, poly(ether-ether-ketone) (PEEK) and a poly-ether-imide (Ultem) were studied after 200 keV boron ion beam treatment at ambient temperature to doses of 2.3x10 14 , 6.8x10 14 , and 2.2x10 15 ions cm -2 . The hardnesses of pristine and boron-implanted materials were characterized by a conventional Knoop method and a load-depth sensing nanoindentation technique. Both measurements showed a significant increase in hardness with increasing dose. The increase in hardness was also found to depend on the penetration depth of the diamond indenter. Wear and friction properties were characterized by a reciprocating sliding friction tester with an SAE 52100 high-carbon, chrome steel ball at 0.5 and 1 N normal loads. Wear and frictional properties varied in a complex fashion with polymer type and dose, but not much with normal load. A substantial reduction in friction coefficient was observed for PEEK at the highest dose but no reduction was observed for Ultem. The wear damage was substantially reduced at the highest dose for both Ultem and PEEK. For the system studied, the highest dose, 2.2x10 15 ions cm -2 , appears to be optimum in improving wear resistance for both PEEK and Ultem. (orig.)

Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

NARCIS (Netherlands)

Koziara, B.T.; Nijmeijer, K.; Benes, N.E.

2015-01-01

The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (≤5 wt%) and not too low spin speeds

Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

NARCIS (Netherlands)

Koziara, Beata; Nijmeijer, Dorothea C.; Benes, Nieck Edwin

2015-01-01

The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds

Improvement of locally produced gasoline and studying its effects on both the performance of the engine and the environment

International Nuclear Information System (INIS)

Hamdan, M.A.; Al-Subaih, T.A.

2002-01-01

This study aims at investigating the effect of methyl-tertiary butyl ether (MTBE) addition to gasoline on its octane number and, hence, the performance of an engine. Also, its effect on the emitted gases was investigated. Locally produced gasoline was blended with five different percentages of MTBE, namely 0%, 5%, 10%, 15% and 20%. Then, these fuels were burned in an engine, which is coupled to a gas analyzer. It was found that the octane number of the gasoline increases continuously and linearly with MTBE percentage in the gasoline. The best performance of the engine occurs at around 10% MTBE addition and this percentage also gives the best reduction in exhaust eases emissions. (author)

Poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) membranes

Energy Technology Data Exchange (ETDEWEB)

Hwang, Mi-Lim; Choi, Jisun; Woo, Hyun-Su; Kumar, Vinod; Sohn, Joon-Yong; Shin, Junhwa, E-mail: shinj@kaeri.re.kr

2014-02-15

Highlights: • PEEK-g-PVBSA, a polymer electrolyte membrane was prepared by a radiation grafting technique. • Poly(ether ether ketone) (PEEK), an aromatic hydrocarbon polymer was used as a grafting backbone film. • The water uptake, proton conductivity, and methanol permeability of the membranes were evaluated. • PEEK-g-PVBSA membranes show considerably lower methanol permeability compared to a Nafion membrane. -- Abstract: In this study, an aromatic hydrocarbon based polymer electrolyte membrane, poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) (PEEK-g-PVBSA), has been prepared by the simultaneous irradiation grafting of vinylbenzyl chloride (VBC) monomer onto a PEEK film and subsequent sulfonation. Each chemical conversion was monitored by FT-IR and SEM–EDX instruments. The physicochemical properties including IEC, water uptake, proton conductivity, and methanol permeability of the prepared membranes were also investigated and found that the values of these properties increase with the increase of degree of grafting. It was observed that the IEC values of the prepared PEEK-g-PVBSA membranes with 32%, 58%, and 80% DOG values were 0.50, 1.05, and 1.22 meq/g while the water uptakes were 14%, 20%, and 21%, respectively. The proton conductivities (0.0272–0.0721 S/cm at 70 °C) were found to be somewhat lower than Nafion 212 (0.126 S/cm at 70 °C) at a relative humidity of 90%. However, the prepared membranes showed a considerably lower methanol permeability (0.61–1.92 × 10{sup −7} cm{sup 2}/s) compared to a Nafion 212 membrane (5.37 × 10{sup −7} cm{sup 2}/s)

The uptake, distribution, metabolism, and excretion of methyl tertiary-butyl ether inhaled alone and in combination with gasoline vapor.

Science.gov (United States)

Benson, Janet M; Tibbetts, Brad M; Barr, Edward B

2003-06-13

The purpose of these studies was to evaluate the tissue uptake, distribution, metabolism, and excretion of methyl tertiary-butyl ether (MTBE) in rats and to determine the effects of coinhalation of the volatile fraction of unleaded gasoline on these parameters. Male F344 rats were exposed nose-only once for 4 h to 4, 40, or 400 ppm 14C-MTBE and to 20 and 200 ppm of the light fraction of unleaded gasoline (LFG) containing 4 and 40 ppm 14C-MTBE, respectively. To evaluate the effects of repeated inhalation of LFG on the fate of inhaled MTBE, rats were exposed for 7 consecutive days to 20 and 200 ppm LFG followed on d 8 by exposure to LFG containing 14C-MTBE. Three subgroups of rats were included for evaluation of respiratory parameters, rates and routes of excretion, and tissue distribution and elimination. MTBE and its chief metabolite, tertiary-butyl alcohol, were quantitated in blood and kidney (immediately after exposure), and the major urinary metabolites, 2-hydroxyisobutyric acid and 2-methyl-1,2- propanediol, were identified and quantified in urine. Inhalation of MTBE alone or as a component of LFG had no concentration-dependent effect on respiratory minute volume. The initial body burdens (IBBs) of MTBE equivalents achieved after 4 h of exposure to MTBE did not increase linearly with exposure concentration. MTBE equivalents rapidly distributed to all tissues examined, with the largest percentages distributed to liver. Between 40 and 400 ppm, there was a significant reduction in percentage of the IBB present in the major organs examined, both immediately and 72 h after exposure. At 400 ppm, the elimination rates of MTBE equivalents from tissues changed significantly. Furthermore, at 400 ppm there was a significant decrease in the elimination half-time of volatile organic compounds (VOCs) in breath and a significant increase in the percentage of the IBB of MTBE equivalents eliminated as VOCs in breath. LFG coexposure significantly decreased the percentage of the

Thermal stability of sulfonated Poly(Ether Ether Ketone) films : on the role of Protodesulfonation

NARCIS (Netherlands)

Koziara, B.T.; Kappert, E.J.; Ogieglo, W.; Nijmeijer, Kitty; Hempenius, M.A.; Benes, N.E.

Thin film and bulk, sulfonated poly(ether ether ketone) (SPEEK) have been subjected to a thermal treatment at 160–250 °C for up to 15 h. Exposing the films to 160 °C already causes partial desulfonation, and heating to temperatures exceeding 200 °C results in increased conjugation in the material,

In vitro evaluation of poly(ethylene glycol)-block-poly(ε-caprolactone) methyl ether copolymer coating effects on cells adhesion and proliferation

Energy Technology Data Exchange (ETDEWEB)

Rusen, Laurentiu [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania); Neacsu, Patricia; Cimpean, Anisoara [University of Bucharest, Department of Biochemistry and Molecular Biology, Bucharest (Romania); Valentin, Ion; Brajnicov, Simona; Dumitrescu, L.N. [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania); Banita, Janina [University of Bucharest, Faculty of Chemistry, Bucharest (Romania); IBAR, Institute of Biochemistry of the Romanian Academy, 296 Splaiul Independentei, RO-060031 Bucharest (Romania); Dinca, Valentina, E-mail: valentina.dinca@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania); Dinescu, Maria [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania)

2016-06-30

Understanding and controlling natural and synthetic biointerfaces is known to be the key to a wide variety of application within cell culture and tissue engineering field. As both material characteristics and methods are important in tailoring biointerfaces characteristics, in this work we explore the feasibility of using Matrix Assisted Pulsed Laser Evaporation technique for obtaining synthetic copolymeric biocoatings (i.e. poly(ethylene glycol)-block-poly(ε-caprolactone) methyl ether) for evaluating in vitro Vero and MC3T3-E1 pre-osteoblasts cell response. Characterization and evaluation of the coated substrates were carried out using different techniques. The Fourier transform infrared spectroscopy data demonstrated that the main functional groups in the MAPLE-deposited films remained intact. Atomic Force Microscopy images showed the coatings to be continuous, with the surface roughness depending on the deposition parameters. Moreover, the behaviour of the coatings in medium mimicking the pH and temperature of the human body was studied and corelated to degradation. Spectro-ellipsometry (SE) and AFM measurements revealed the degradation trend during immersion time by the changes in coating thickness and roughness. In vitro biocompatibility was studied by indirect contact tests on Vero cells in accordance with ISO 10993-5/2009. The results obtained in terms of cell morphology (phase contrast microscopy) and cytotoxicity (LDH and MTT assays) proved biocompatibility. Furthermore, direct contact assays on MC3T3-E1 pre-osteoblasts demonstrated the capacity of all analyzed specimens to support cell adhesion, normal cellular morphology and growth.

In vitro evaluation of poly(ethylene glycol)-block-poly(ɛ-caprolactone) methyl ether copolymer coating effects on cells adhesion and proliferation

Science.gov (United States)

Rusen, Laurentiu; Neacsu, Patricia; Cimpean, Anisoara; Valentin, Ion; Brajnicov, Simona; Dumitrescu, L. N.; Banita, Janina; Dinca, Valentina; Dinescu, Maria

2016-06-01

Understanding and controlling natural and synthetic biointerfaces is known to be the key to a wide variety of application within cell culture and tissue engineering field. As both material characteristics and methods are important in tailoring biointerfaces characteristics, in this work we explore the feasibility of using Matrix Assisted Pulsed Laser Evaporation technique for obtaining synthetic copolymeric biocoatings (i.e. poly(ethylene glycol)-block-poly(ɛ-caprolactone) methyl ether) for evaluating in vitro Vero and MC3T3-E1 pre-osteoblasts cell response. Characterization and evaluation of the coated substrates were carried out using different techniques. The Fourier transform infrared spectroscopy data demonstrated that the main functional groups in the MAPLE-deposited films remained intact. Atomic Force Microscopy images showed the coatings to be continuous, with the surface roughness depending on the deposition parameters. Moreover, the behaviour of the coatings in medium mimicking the pH and temperature of the human body was studied and corelated to degradation. Spectro-ellipsometry (SE) and AFM measurements revealed the degradation trend during immersion time by the changes in coating thickness and roughness. In vitro biocompatibility was studied by indirect contact tests on Vero cells in accordance with ISO 10993-5/2009. The results obtained in terms of cell morphology (phase contrast microscopy) and cytotoxicity (LDH and MTT assays) proved biocompatibility. Furthermore, direct contact assays on MC3T3-E1 pre-osteoblasts demonstrated the capacity of all analyzed specimens to support cell adhesion, normal cellular morphology and growth.

Polybrominated diphenyl ethers fate in China: a review with an emphasis on environmental contamination levels, human exposure and regulation.

Science.gov (United States)

Chen, Yuan; Li, Jinhui; Liu, Lili; Zhao, Nana

2012-12-30

Because of their highly effective flame-retardant capability, polybrominated diphenyl ethers (PBDEs) have been extensively used as flame retardants in consumer goods. However, compelling evidence shows that many congeners of PBDEs have been accumulating in the environment, in biota and in human populations worldwide. In China, although octabrominated diphenyl ether (octaBDE) has never been produced or used, pentabrominated diphenyl ether (pentaBDE) and decabrominated diphenyl ether (decaBDE) have been produced and used in large quantities. In the face of increasing evidence about PBDE pollution and the adoption of international conventions, there is a growing push for China to develop more stringent methods of managing PBDE waste. This paper summarizes the information about PBDE production and application, describes the flame-retarding mechanism, and then reviews the toxicity and levels of PBDEs in China's environmental media and human tissues. Based on international regulations on PBDEs, the paper finally puts forward some suggestions for Chinese policy making and for self-regulation within the flame retardant industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

O-methylation of natural phenolic compounds based on green chemistry using dimethyl carbonate

Science.gov (United States)

Prakoso, N. I.; Pangestu, P. H.; Wahyuningsih, T. D.

2016-02-01

The alkyl aryl ether compounds, of which methyl eugenol and veratraldehyde are the simplest intermediates can be synthesized by reacting eugenol and vanillin with the green reagent dimethyl carbonate (DMC). The reaction was carried out under mild of temperature and pressure. Excellent yields and selective products were obtained (95-96%) after a few hours. In the end of the reaction, the catalysts (base and Phase Transfer Catalyst) can be recovered and regenerated.

Radioisotope tracer study of co-reactions of methanol with ethanol using 11C-labelled methanol over alumina and H-ZSM-5

International Nuclear Information System (INIS)

Sarkadi-Priboczki, E.; Kovacs, Z.; Kumar, N.; Salmi, T.; Murzin, D.Yu

2005-01-01

Complete text of publication follows. The transformation of methanol has been investigated over alumina and H-ZSM-5 in our previous experiments by 11 C-radioisotope tracing. The main product in methanol conversion over alumina was dimethyl ether due to Lewis acid sites while over H-ZSM-5 mostly hydrocarbons were formed due to both Lewis and Brrnsted acid sites. With increasing temperature first the ethanol was dehydrated to diethyl ether followed by ethene formation over alumina and H-ZSM-5. In this work, 11 C-labelled methanol as radioisotope tracer was added to non-radioactive methanol for investigation of co-reaction with non-radioactive ethanol over alumina and H- ZSM-5. The 11 C-methanol tracer was used to distinguish the methanol derivates and co-reaction derivates of methanol with ethanol against non-radioactive ethanol derivates. The yield of methyl ethyl ether as mixed ether and the influence of ethanol for the yields of C 1 -C 5 hydrocarbons were studied as a function of reaction temperature and contact time. The 11 C-methanol was formed by a radiochemical process from 11 CO 2 produced at cyclotron. The mixture of methanol and ethanol was added to 11 C-methanol and injected to the catalyst. The catalysis was carried out in a glass tube fixed-bed reactor after its pretreatment. The derivates were analyzed by radio-gas chromatography (gas chromatograph with thermal conductivity detector coupled on-line with a radioactivity detector). The comparative analysis of yields of radioactive and non-radioactive products as a function of reaction temperature gives information about the reaction pathways. Over alumina the yields of dimethyl ether and methyl ethyl ether (co-product) as radioactive and diethyl ether with ethene as non-radioactive main products were monitored as a function of reaction temperature and reaction time in the range of 513-593 K. Alongside ethanol derivates the ethene turns into main product in contrast with methyl ethyl ether and diethyl

Gold( i )-catalysed dehydrative formation of ethers from benzylic alcohols and phenols

KAUST Repository

Veenboer, Richard M. P.

2015-01-01

© The Royal Society of Chemistry 2015. We report the cross-dehydrative reaction of two alcohols to form unsymmetrical ethers using NHC-gold(i) complexes (NHC = N-heterocyclic carbene). Our progress in developing this reaction into a straightforward procedure is discussed in detail. The optimised methodology proceeds under mild reaction conditions and produces water as the sole by-product. The synthetic utility of this environmentally benign methodology is exemplified by the formation of a range of new ethers from readily available phenols bearing electron withdrawing substituents and secondary benzylic alcohols with various substituents. Finally, we present experimental results to account for the chemoselectivity obtained in these reactions.

On new physical reality (on ψ-ether)

International Nuclear Information System (INIS)

Isaev, P.S.

2002-01-01

It is shown that there exists a new physical reality - the ψ-ether. All the achievements of quantum mechanics and quantum field theory are due to the fact that both the theories include the influence of ψ-ether on the physical processes occurring in the Universe. Physics of the XX century was first of all the physics of ψ-ether

Aerobic degradation of methyl tert-butyl ether in a closed symbiotic system containing a mixed culture of Chlorella ellipsoidea and Methylibium petroleiphilum PM1.

Science.gov (United States)

Zhong, Weihong; Li, Yixiao; Sun, Kedan; Jin, Jing; Li, Xuanzhen; Zhang, Fuming; Chen, Jianmeng

2011-01-30

The contamination of groundwater by methyl tert-butyl ether (MTBE) is one of the most serious environmental problems around the world. MTBE degradation in a closed algal-bacterial symbiotic system, containing a mixed culture of Methylibium petroleiphilum PM1 and Chlorella ellipsoidea, was investigated. The algal-bacterial symbiotic system showed increased MTBE degradation. The MTBE-degradation rate in the mixed culture (8.808 ± 0.007 mg l(-1) d(-1)) was higher than that in the pure bacterial culture (5.664 ± 0.017 mg l(-1) d(-1)). The level of dissolved oxygen was also higher in the mixed culture than that in the pure bacterial culture. However, the improved efficiency of MTBE degradation was not in proportional to the biomass of the alga. The optimal ratio of initial cell population of bacteria to algae was 100:1. An immobilized culture of mixed bacteria and algae also showed higher MTBE degradation rate than the immobilized pure bacterial culture. A mixed culture with algae and PM1 immobilized separately in different gel beads showed higher degradation rate (8.496 ± 0.636 mg l(-1) d(-1)) than that obtained with algae and PM1 immobilized in the same gel beads (5.424 ± 0.010 mg l(-1) d(-1)). Copyright © 2010 Elsevier B.V. All rights reserved.

Discovery of potent and selective acetylcholinesterase (AChE) inhibitors: acacetin 7-O-methyl ether Mannich base derivatives synthesised from easy access natural product naringin.

Science.gov (United States)

Liu, Hao-Ran; Men, Xue; Gao, Xiao-Hui; Liu, Lin-Bo; Fan, Hao-Qun; Xia, Xin-Hua; Wang, Qiu-An

2018-03-01

Naringin, as a component universal existing in the peel of some fruits or medicinal plants, was usually selected as the material to synthesise bioactive derivates since it was easy to gain with low cost. In present investigation, eight new acacetin-7-O-methyl ether Mannich base derivatives (1-8) were synthesised from naringin. The bioactivity evaluation revealed that most of them exhibited moderate or potent acetylcholinesterase (AChE) inhibitory activity. Among them, compound 7 (IC 50 for AChE = 0.82 ± 0.08 μmol•L -1 , IC 50 for BuChE = 46.30 ± 3.26 μmol•L -1 ) showed a potent activity and high selectivity compared with the positive control Rivastigmine (IC 50 for AChE = 10.54 ± 0.86 μmol•L -1 , IC 50 for BuChE = 0.26 ± 0.08 μmol•L -1 ). The kinetic study suggested that compound 7 bind to AChE with mix-type inhibitory profile. Molecular docking study revealed that compound 7 could combine both catalytic active site (CAS) and peripheral active site (PAS) of AChE with four points (Trp84, Trp279, Tyr70 and Phe330), while it could bind with BuChE via only His 20.

Constraining the Molecular Complexity in the Interstellar Medium—The Formation of Ethyl Methyl Ether (CH3OCH2CH3) in Star-forming Regions

Science.gov (United States)

Bergantini, Alexandre; Frigge, Robert; Kaiser, Ralf I.

2018-05-01

We report the first confirmed synthesis of ethyl methyl ether (EME, CH3CH2OCH3) within astrophysical model ices containing water (H2O) and methane (CH4) exposed to ionizing radiation at ultra-low temperatures of 5 K. EME (also known as methoxyethane), was recently observed toward Orion KL and currently is the largest confirmed oxygen-bearing molecule found in the interstellar medium. Exploiting isomer-selective photoionization (PI) of the subliming molecules in the temperature-programmed desorption phase at 10.49, 9.92, and 9.70 eV, coupled with reflectron time-of-flight mass spectrometry and isotopic substitution experiments (H2 18O–CH4), the detection of fragment ions of EME at m/z = 45 (C2H5O+) and m/z = 59 (C3H7O+), and probing the proton transfer in subliming ethanol–EME complexes via m/z = 61 (C3H9O+), the present study reveals that EME can be formed from suprathermal reactions initiated by cosmic rays and secondary electrons generated within astrophysical ices. The detection of EME in our experiments represents a significant advance in the understanding of formation pathways of complex organic molecules present in hot cores and helps to constrain astrochemical models on the formation of such species within molecular clouds.

Amended final report on the safety assessment of PPG-40 butyl ether with an addendum to include PPG-2, -4, -5, -9, -12, -14, -15, -16, -17, -18, -20, -22, -24, -26, -30, -33, -52, and -53 butyl ethers.

Science.gov (United States)

Lanigan, R S

2001-01-01

The Polypropylene Glycol (PPG) Butyl Ethers function as skinand hair-conditioning agents in cosmetics. Intestinal absorption of the PPG Butyl Ethers was inversely proportional to the molecular weight. In general, the toxicity of the PPG Butyl Ethers decreased as the molecular weight increased. In acute studies, moderate intraperitoneal (IP) doses of various PPG Butyl Ethers caused convulsive seizures in mice and anesthetized dogs, and large oral doses caused decreased activity, anuria, renal tubular swelling and necrosis, and hepatic swelling and necrosis. PPG-2 Butyl Ether vapors were nontoxic by the inhalation route. PPG-2 Butyl Ether was nontoxic in short-term feeding and dermal exposure studies in rats. In animal irritation studies, PPG-2 Butyl Ether caused minor, transient erythema and desquamation; in addition, erythema, edema, ecchymosis, necrosis, and other changes were observed during an acute percutaneous study. PPG-2 Butyl Ether also caused minor to moderate conjunctival irritation and minor corneal injury. PPG-2 Butyl Ether when dermally applied was nontoxic to pregnant rats and was nonteratogenic at doses up to 1.0 ml/kg/day. PPG BE800 at concentrations of 0.001% to 0.26% in feed was noncarcinogenic to rats after 2 years of treatment. In clinical studies, PPG BE800 was nonirritating and nonsensitizing to the skin when tested using 200 subjects. PPG-40 Butyl Ether was neither an irritant nor a sensitizer in a repeat-insult patch test using 112 subjects. Although clinical testing did not indicate significant skin irritation is produced by these ingredients, the animal test data did indicate the potential that these ingredients can be irritating. Therefore, it was concluded that the PPG Butyl Ethers can be used safely in cosmetic products if they are formulated to avoid irritation. Data on the component ingredients, Propylene Glycol, PPG, and n-Butyl Alcohol, from previous cosmetic ingredient safety assessments were also considered and found to support

Rhodocomatulin-Type Anthraquinones from the Australian Marine Invertebrates Clathria hirsuta and Comatula rotalaria.

Science.gov (United States)

Khokhar, Shahan; Pierens, Gregory K; Hooper, John N A; Ekins, Merrick G; Feng, Yunjiang; Davis, Rohan A

2016-04-22

Chemical investigations of an Australian sponge, Clathria hirsuta, from the Great Barrier Reef, have resulted in the isolation of two known anthraquinones, rhodocomatulin 5,7-dimethyl ether (1) and rhodocomatulin 7-methyl ether (2). Additionally, four new anthraquinone metabolites, 6-methoxyrhodocomatulin 7-methyl ether, 3-bromo-6-methoxy-12-desethylrhodocomatulin 7-methyl ether, 3-bromo-6-methoxyrhodocomatulin 7-methyl ether, and 3-bromorhodocomatulin 7-methyl ether (3-6), were also isolated and characterized. This is the first report of the rhodocomatulin-type anthraquinones from a marine sponge, as 1 and 2 were previously isolated from the marine crinoid genus Comatula. An additional chemical investigation of the marine crinoid Comatula rotalaria enabled the isolation of further quantities of 1 and 2, as well as two additional new crinoid metabolites, 12-desethylrhodocomatulin 5,7-dimethyl ether and 12-desethylrhodocomatulin 7-methyl ether (7 and 8). An NMR spectroscopic analysis of compounds 7 and 8 provided further insight into the rhodocomatulin planar structure and, together with the successful implementation of DFT-NMR calculations, confirmed that the rhodocomatulin metabolites existed as para rather than ortho quinones.

COMBUSTION ANALYSIS OF ALGAL OIL METHYL ESTER IN A DIRECT INJECTION COMPRESSION IGNITION ENGINE

Directory of Open Access Journals (Sweden)

HARIRAM V.

2013-02-01

Full Text Available Algal oil methyl ester was derived from microalgae (Spirulina sp. The microalga was cultivated in BG 11 media composition in a photobioreactor. Upon harvesting, the biomass was filtered and dried. The algal oil was obtained by a two step solvent extraction method using hexane and ether solvent. Cyclohexane was added to biomass to expel the remaining algal oil. By this method 92% of algal oil is obtained. Transesterification process was carried out to produce AOME by adding sodium hydroxide and methanol. The AOME was blended with straight diesel in 5%, 10% and 15% blend ratio. Combustion parameters were analyzed on a Kirloskar single cylinder direct injection compression ignition engine. The cylinder pressure characteristics, the rate of pressure rise, heat release analysis, performance and emissions were studied for straight diesel and the blends of AOME’s. AOME 15% blend exhibits significant variation in cylinder pressure and rate of heat release.

Structural characterization of ether lipids from the archaeon Sulfolobus islandicus by high-resolution shotgun lipidomics

DEFF Research Database (Denmark)

Jensen, Sara Munk; Brandl, Martin; Treusch, Alexander H

2015-01-01

The molecular structures, biosynthetic pathways and physiological functions of membrane lipids produced by organisms in the domain Archaea are poorly characterized as compared with that of counterparts in Bacteria and Eukaryota. Here we report on the use of high-resolution shotgun lipidomics......-resolution Fourier transform mass spectrometry using an ion trap-orbitrap mass spectrometer. This analysis identified five clusters of molecular ions that matched ether lipids in the database with sub-ppm mass accuracy. To structurally characterize and validate the identities of the potential lipid species, we...... performed structural analysis using multistage activation on the ion trap-orbitrap instrument as well as tandem mass analysis using a quadrupole time-of-flight machine. Our analysis identified four ether lipid species previously reported in Archaea, and one ether lipid species that had not been described...

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

Energy Technology Data Exchange (ETDEWEB)

1990-08-15

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.

Sulfonated poly(ether ether ketone) membranes for electric double layer capacitors

International Nuclear Information System (INIS)

Kim, Wan Ju; Kim, Dong-Won

2008-01-01

Sulfonated poly(ether ether ketone) (S-PEEK) with different degree of sulfonation (DS) has been prepared and evaluated as a proton conducting membrane for electric double layer capacitor (EDLC). The polymer electrolytes prepared with S-PEEK membrane exhibited ionic conductivities about 1.2 x 10 -3 -4.5 x 10 -3 S cm -1 at room temperature, which depended on both soaking solvent and degree of sulfonation. The quasi-solid-state EDLCs consisted of activated carbon electrodes and S-PEEK membrane were assembled, and their electrochemical characteristics were studied by cyclic voltammetry and charge-discharge cycle tests. The effect of DS on the electrochemical performances of EDLCs has been investigated

Extraction of flavonoids from garden (Salvia officinalis L. and glutinous (Salvia glutinosa L. sage by ultrasonic and classical maceration

Directory of Open Access Journals (Sweden)

DRAGAN T. VELICKOVIC

2007-01-01

Full Text Available Flavonoids were analysed in the extracts of garden (Salvia officinalis L. and glutinous (Salvia glutinosa L. sage. Ultrasonic extraction (20 minutes at 40 °C and classical maceration (6 h at room temperature of the extractable substances from dried herbs and dried residual plant materials from which the essential oil had previously been removed by hydrodistillation were performed with petroleum ether, 70 % aqueous solution of ethanol and water. It was found that the extracts from both plants contained flavonoids, but their compositions were dependent of the plant species, the polarity of the extracting solvent and the extraction technique applied. Apigenin and its derivatives (e.g., apigenin 4'-methyl ether, scutellarein 6-methyl ether, isoscutellarein 8-methyl ether, luteolin and 6-OH-luteolin-6-methyl ether where distinctive for S. officinalis. Apigenin, luteolin, 6-OH-luteolin-6-methyl ether, kaempherol 3-methyl ether, kaempherol 3,7-dimethyl ether, quercetin 3,7,3'-trimethyl ether and quercetin 3,7,3',4'-tetramethyl ether were distinctive for S. glutinosa. The flavonoids were also detected in considerable quantities in the plant material from which the essential oils had been already removed. Hence, this industrial waste plant material might be further used as a source of the flavonoids.

Radioactive (14C) tracer studies of methanol conversion over a Ni-ZSM-5 zeolite

International Nuclear Information System (INIS)

Hwu, F.S.; Hightower, J.W.

1983-01-01

Secondary reactions have been identified in the overall conversion of methanol to hydrocarbons over a Ni-ZSM-5 catalyst. The major conclusions are: (1) The alkylation of light olefins with methanol or methyl ether is one pathway for the formation of larger olefins with one more carbon atom. (2) Paraffins are produced primarily by hydrogen transfer to the corresponding olefin. (3) Except for minor cracking reactions, paraffins with no more than 7 carbon atoms, are final stable products; isomerization among paraffin isomers does not take place at 368 0 C. (4) Light olefins, e.g. ethylene, propylene, and butenes, are reactive intermediates for aromatics formation. (5) Aromatic compounds may also be produced by methanol- methyl ether-alkylation of benzene and subsequent alkylated benezenes. 2 figures, 3 tables

Promoting environmentally sound management of polybrominated diphenyl ethers in Asia.

Science.gov (United States)

Li, Jinhui; Zhao, Nana; Liu, Xue; Wu, Xiaoyang

2014-06-01

Polybrominated diphenyl ethers with persistent organic pollutant properties are required to be controlled by the Stockholm Convention. Recently, polybrominated diphenyl ether contamination has become widespread in Asia, mainly because of the disposal and recycling processes of polybrominated diphenyl ether-containing wastes. The management status, production, usage, import/export, treatment, and disposal, as well as implementation deficiencies for the environmentally sound management of polybrominated diphenyl ethers and polybrominated diphenyl ether-containing materials in ten Asian countries were investigated and assessed in this study. This information could help the participating countries implement the Stockholm Convention and could promote the regional environmentally sound management of polybrominated diphenyl ether-containing articles and products. The results obtained were as follows. (1) Most of the countries studied lacked environmental policies and regulations, or even standards of polybrominated diphenyl ether pollution management and emission control actions. Accurate data on the consumption and importation of polybrominated diphenyl ether-containing materials, however, were not available for all the participating countries. In addition, there were no special treatment or disposal systems for polybrominated diphenyl ether-containing materials, or emission-cutting measures for the treatment of waste in these countries, owing to the lack of sufficient funding or technologies. (2) The improper dismantling of e-waste is a major source of polybrominated diphenyl ether emissions in these countries. (3) Proper e-waste management could result in a breakthrough in the environmentally sound management of this major polybrominated diphenyl ether-containing material flow, and could significantly reduce polybrominated diphenyl ether emissions. Finally, based on the study results, this article puts forward some recommendations for improving the environmentally

Production of Methyl Laurate from Coconut Cream through Fractionation of Methyl Ester

Directory of Open Access Journals (Sweden)

Johnner P. Sitompul

2015-10-01

Full Text Available This paper concerns the production of methyl laurate from coconut cream through fractionation of methyl esters. Coconut oil was produced by wet processing of coconut cream. The esters were prepared by reacting coconut oil and methanol using homogeneous catalyst KOH in a batch reactor, followed by fractionation of fatty acid methyl esters (FAME at various reduced pressures applying differential batch vacuum distillation. Experimental data were compared with simulation of a batch distillation employing the simple Raoult’s model and modified Raoult’s model of phase equilibria. Activity coefficients (γi were determined by optimization to refine the models. The modified Rault’s model with activity coefficients gave better agreement with the experimental data, giving the value of γi between 0,56-0,73. For a given boiling temperature, lower operating pressure produced higher purity of C10 and C12 FAME for respective distillates.

Synthesis of methyl propanoate by Baeyer-Villiger monooxygenases

NARCIS (Netherlands)

van Beek, Hugo L.; Winter, Remko T.; Eastham, Graham R.; Fraaije, Marco W.

2014-01-01

Methyl propanoate is an important precursor for polymethyl methacrylates. The use of a Baeyer-Villiger monooxygenase (BVMO) to produce this compound was investigated. Several BVMOs were identified that produce the chemically non-preferred product methyl propanoate in addition to the normal product

Chemoselective Deprotection of Triethylsilyl Ethers

Science.gov (United States)

Chandra, Tilak; Broderick, William E.; Broderick, Joan B.

2009-01-01

An efficient and selective method was developed for the deprotection of triethylsilyl (TES) ethers using formic acid in methanol (5–10%) or in methylene chloride 2–5%) with excellent yields. TES ethers are selectively deprotected to the corresponding alcohols in high yields using formic acid in methanol under mild reaction conditions. Other hydroxyl protecting groups like t-butyldimethylsilyl (TBDMS) remain unaffected. PMID:20183570

Hydrodebromination of decabromodiphenyl ether (BDE-209) in cooking experiments with salmon fillet.

Science.gov (United States)

Bendig, Paul; Blumenstein, Marina; Hägele, Florian; Vetter, Walter

2012-08-29

Polybrominated diphenyl ethers (PBDEs) are environmental contaminants regularly detected in biota and food. Seafood has been identified as the major dietary source for human uptake. Fish is predominantly consumed after cooking, and this process may alter the actual human intake of contaminants. This study thus aimed to investigate the fate of PBDEs in this cooking process. Heating of fish fortified with 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE-209) at typical cooking conditions (200 °C, in plant oil) resulted in a decrease of its concentration in favor of the formation of lower brominated congeners. After 15 min, ∼25% of BDE-209 was transformed into nona- to octabrominated congeners. The major transformation route was BDE-209 → BDE-206 → BDE-196 and BDE-199. Low amounts of heptabrominated congeners as well as one hexabromodibenzofuran and a heptabromodibenzofuran isomer were also detected. However, penta- and tetrabrominated diphenyl ethers were not observed, and heating of BDE-47 did not produce new transformation products.

Laboratory rotational spectrum of singly 13C-substituted dimethyl ether up to 1.5 THz and interstellar detection of 13CH_3O12CH_3 - a fruitful interplay between laboratory work and inter

Science.gov (United States)

Koerber, M.; Bisschop, S.; Endres, C.; Lewen, F.; Schlemmer, S.

2011-05-01

Dimethyl ether (CH_3OCH_3) is found in high abundance in star forming regions. However, the interstellar formation process of dimethyl ether still remains unclear up to now. In current gas-grain models gas-phase synthesis via self-methylation of methanol evaporating from grains is discussed in contrast to the surface reaction of CH_3 with successively hydrogenated CO (Garrod & Herbst 2006). An observational test for the formation mechanism has been proposed by Charnley et al. (2004) making use of the 13C fractionation into CO at low temperatures on grains: Comparing the 12C/13C ratio of molecules to the 12CO/13CO ratio allows to distinguish between formation from CO on cold grains and pure gas-phase formation routes. The isotopic ratio of species like dimethyl ether thus can be used as a tracer of the chemical evolution of the observed region. Due to its two methyl groups undergoing large amplitude motions and a relatively strong dipole moment of μ = 1.302 D it shows a strong and dense complex spectrum all over the terahertz region relevant for Herschel and ALMA observations. Accurate transition frequencies are needed to interpret the astronomical spectra. For the main isotopologue extensive data are now available (Endres et al. 2009). However, due to the greatly improved sensitivity of the new observatories isotopic species of abundant molecules like dimethyl ether are appearing in the spectra as well. In this work we present laboratory measurements of singly 13C-substituted dimethyl ether (13CH_3O12CH_3) up to 1.5 THz. More than 1700 transitions of 13CH_3O12CH_3 with rotational quantum numbers up to J = 53 and K = 25 have been analyzed. Based on the laboratory measurements singly 13C-substituted dimethyl ether has been detected for the first time in the spectrum of G327.3-0.6 (Bisschop et al. in prep.) and a preliminary value for the 12C/13C abundance ratio has been determined.

[Early contributions from Erlangen to the theory and practice of ether and chloroform anesthesia. 1. Heyfelder's clinical trial with ether and chloroform].

Science.gov (United States)

Hintzenstern, U v; Schwarz, W

1996-02-01

The era of modern anaesthesia in Germany began on January 24th, 1847. This day, professor in ordinary Johann Ferdinand Heyfelder anaesthetized a patient with sulphuric ether in the clinic of surgery and ophthalmology of the University of Erlangen. By March 17th, 1847, Heyfelder had performed 121 surgical procedures under ether. The operations in majority were teeth-extractions, and a few more complex operations such as the treatment of a harelip or of lip cancer or the resection of the shoulder joint. Heyfelder described in detail 108 of these inhalations in a little book entitled The experiments with sulphuric ether. This monograph published in March, 1847, represents one of the first complete dissertations on sulphuric ether in the German literature. In a special chapter he analyzed the development of various physiological and psychological parameters during etherization. Heyfelder also examined blood and urine of some etherized patients and reported that he did not find any important or specific alterations. In 1847, Heyfelder was probably the first to apply salt-ether in man. After 4 administrations he concluded that salt ether acted more quickly but shorter than sulphuric ether. Advantageous were its application without problems and ease of induction. Disadvantageous were its high volatility, its price and the difficulty of getting it in a pure form. From December, 1847, on Heyfelder started to use chloroform. He was now able to perform more major operations, for example, the total resection of the hip-joint. In his book The experiments with sulphuric ether, salt ether, and chloroform he describes a great number of anaesthetic administrations using these 3 agents. In his summary Heyfelder concluded, that chloroform was undoubtly superior to sulphuric ether mainly because it was a quicker acting and longer lasting agent and leads to deeper narcosis. Moreover its application was much easier for it needed no special apparatus. However, because of its great

Preparation and characterization of sulfonated amine-poly(ether sulfone)s for proton exchange membrane fuel cell

Energy Technology Data Exchange (ETDEWEB)

Seo, Dong-Wan; Lim, Young-Don; Lee, Soon-Ho; Jeong, Young-Gi; Kim, Whan-Gi [Department of Applied Chemistry/RIC-ReSEM, Konkuk University, Chungju-si, Chungbuk 380-701 (Korea, Republic of); Hong, Tae-Whan [Department of Materials Sci and Engineering/RIC-ReSEM, Chungju National University, Chungju, Chungbuk (Korea, Republic of)

2010-12-15

Sulfonated amine-poly(ether sulfone)s (S-APES)s were prepared by nitration, reduction and sulfonation of poly(ether sulfone) (ultrason {sup registered} -S6010). Poly(ether sulfone) was reacted with ammonium nitrate and trifluoroacetic anhydride to produce the nitrated poly(ether sulfone), and was followed by reduction using tin(II)chloride and sodium iodide as reducing agents to give the amino-poly(ether sulfone). The S-APES was obtained by reaction of 1,3-propanesultone and the amino-poly(ether sulfone) (NH{sub 2}-PES) with sodium methoxide. The different degrees of nitration and reduction of poly(ether sulfone) were successfully synthesized by an optimized process. The reduction of nitro group to amino was done quantitatively, and this controlled the contents of the sulfonic acid group. The films were converted from salt to acid forms with dilute hydrochloric acid. Different contents of sulfonated unit of the S-APES were studied by FT-IR, {sup 1}H NMR spectroscopy, differential scanning calorimetry (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The ion exchange capacity (IEC), a measure of proton conductivity, was evaluated. The S-APES membranes exhibit conductivities (25 C) from 1.05 x 10{sup -3} to 4.83 x 10{sup -3} S/cm, water swell from 30.25 to 66.50%, IEC from 0.38 to 0.82 meq/g, and methanol diffusion coefficients from 3.10 x 10{sup -7} to 4.82 x 10{sup -7} cm{sup 2}/S at 25 C. (author)

Palladium-Catalyzed Reductive Insertion of Alcohols into Aryl Ether Bonds

Energy Technology Data Exchange (ETDEWEB)

Wang, Meng [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Gutiérrez, Oliver Y. [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Camaioni, Donald M. [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Lercher, Johannes A. [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Department of Chemistry and Catalysis Research Institute, TU München, Lichtenbergstrasse 4 85748 Garching Germany

2018-03-06

Pd/C catalyzes C-O bond cleavage of aryl ethers (diphenyl ether and cyclohexyl phenyl ether) by methanol in H2. The aromatic C-O bond is cleaved by reductive methanolysis, which is initiated by Pd-catalyzed partial hydrogenation of one phenyl ring to form an enol ether. The enol ether reacts rapidly with methanol to form a ketal, which generates methoxycyclohexene by eliminating phenol or an alkanol. Subsequent hydrogenation leads to methoxycyclohexane.

Modified nanocrystal cellulose/fluorene-containing sulfonated poly(ether ether ketone ketone) composites for proton exchange membranes

Science.gov (United States)

Wei, Yingcong; Shang, Yabei; Ni, Chuangjiang; Zhang, Hanyu; Li, Xiaobai; Liu, Baijun; Men, Yongfeng; Zhang, Mingyao; Hu, Wei

2017-09-01

Highly sulfonated poly(ether ether ketone ketone)s (SFPEEKKs) with sulfonation degrees of 2.34 (SFPEEKK5) and 2.48 (SFPEEKK10) were synthesized through the direct sulfonation of a fluorene-containing poly(ether ether ketone ketone) under a relatively mild reaction condition. Using the solution blending method, sulfonated nanocrystal cellulose (sNCC)-enhanced SFPEEKK composites (SFPEEKK/sNCC) were successfully prepared for investigation as proton exchange membranes. Transmission electron microscopy showed that sNCC was uniformly distributed in the composite membranes. The properties of the composite membranes, including thermal stability, mechanical properties, water uptake, swelling ratio, oxidative stability and proton conductivity were thoroughly evaluated. Results indicated that the insertion of sNCC could contribute to water management and improve the mechanical performance of the membranes. Notably, the proton conductivity of SFPEEKK5/sNCC-5 was as high as 0.242 S cm-1 at 80 °C. All data proved the potential of SFPEEKK/sNCC composites for proton exchange membranes in medium-temperature fuel cells.

Microwave sintering of poly-ether-ether-ketone (PEEK) based coatings deposited on metallic substrate

International Nuclear Information System (INIS)

Zhang, G.; Leparoux, S.; Liao, H.; Coddet, C.

2006-01-01

In this paper, the feasibility of microwave (MW) sintering PEEK (poly-ether-ether-ketone) based coatings was investigated. Three coatings were studied: pure PEEK, micron-SiC and nano-SiC particles filled (wt.10%) PEEK coatings. The results indicate that, for the two composite coatings, the SiC particles distributed in the polymer matrix, as a good MW susceptor, could be heated preferentially by MW radiation. Consequently, the polymer matrix was heated by these particles

Influence of Chemical Blends on Palm Oil Methyl Esters’ Cold Flow Properties and Fuel Characteristics

Directory of Open Access Journals (Sweden)

Obed M. Ali

2014-07-01

Full Text Available Alternative fuels, like biodiesel, are being utilized as a renewable energy source and an effective substitute for the continuously depleting supply of mineral diesel as they have similar combustion characteristics. However, the use of pure biodiesel as a fuel for diesel engines is currently limited due to problems relating to fuel properties and its relatively poor cold flow characteristics. Therefore, the most acceptable option for improving the properties of biodiesel is the use of a fuel additive. In the present study, the properties of palm oil methyl esters with increasing additive content were investigated after addition of ethanol, butanol and diethyl ether. The results revealed varying improvement in acid value, density, viscosity, pour point and cloud point, accompanied by a slight decrease in energy content with an increasing additive ratio. The viscosity reductions at 5% additive were 12%, 7%, 16.5% for ethanol, butanol and diethyl ether, respectively, and the maximum reduction in pour point was 5 °C at 5% diethyl ether blend. Engine test results revealed a noticeable improvement in engine brake power and specific fuel consumption compared to palm oil biodiesel and the best performance was obtained with diethyl ether. All the biodiesel-additive blend samples meet the requirements of ASTM D6751 biodiesel fuel standards for the measured properties.

Landfills as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

Science.gov (United States)

Weinberg, Ingo; Dreyer, Annekatrin; Ebinghaus, Ralf

2011-02-01

In order to investigate landfills as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two landfills (one active and one closed) and two reference sites using high volume air samplers. Contaminants were accumulated on glass fiber filters (particle phase) and PUF/XAD-2/PUF cartridges (gas phase), extracted by methyl-tert butyl ether/acetone (neutral PFCs), methanol (ionic PFCs) or hexane/acetone (PBDEs, musk fragrances), and detected by GC-MS (neutral PFCs, PBDEs, musk fragrances) or HPLC-MS/MS (ionic PFCs). Total concentrations ranged from 84 to 706 pg m -3 (volatile PFCs, gas phase), from fragrances, gas + particle phase) and from 1 to 11 pg m -3 (PBDEs, gas + particle phase). Observed sum concentrations of PFCs and synthetic musk fragrances and partly PBDE concentrations were elevated at landfill sites compared to corresponding reference sites. Concentrations determined at the active landfill were higher than those of the inactive landfill. Overall, landfills can be regarded as a source of synthetic musk fragrances, several PFCs and potentially of PBDEs to ambient air.

Actinide/crown ether chemistry

International Nuclear Information System (INIS)

Benning, M.M.

1988-01-01

A structural survey of actinide/crown ether compounds was conducted in order to investigate the solid state chemistry of these complexes. Several parameters - the metal size, crown type, counterion, solvent systems and reaction and crystallization conditions - were varied to correlate their importance in complexation. Under atmospheric conditions, two types of complexes were isolated, those containing only hydrogen-bonded crown interactions and instances where the crown interacts directly with the metal center. In both cases, water seems to play a very important role. When coordinated to the metal, water molecules exhibit the necessary donor properties required for the formation of hydrogen-bonded contacts. The water molecules also provide fierce competition with the crown ethers for metal-binding sites and in most cases prohibit the formation of complexes in which direct metal-ligand association exists. The results of this study indicate that direct interaction between the metal atoms and the crown ethers, in the presence of water, can only occur with polyether conformations which limit the steric replusions within the metal coordination sphere

Detection of DNA methylation changes in micropropagated banana plants using methylation-sensitive amplification polymorphism (MSAP).

Science.gov (United States)

Peraza-Echeverria, S; Herrera-Valencia, V A.; Kay, A -J.

2001-07-01

The extent of DNA methylation polymorphisms was evaluated in micropropagated banana (Musa AAA cv. 'Grand Naine') derived from either the vegetative apex of the sucker or the floral apex of the male inflorescence using the methylation-sensitive amplification polymorphism (MSAP) technique. In all, 465 fragments, each representing a recognition site cleaved by either or both of the isoschizomers were amplified using eight combinations of primers. A total of 107 sites (23%) were found to be methylated at cytosine in the genome of micropropagated banana plants. In plants micropropagated from the male inflorescence explant 14 (3%) DNA methylation events were polymorphic, while plants micropropagated from the sucker explant produced 8 (1.7%) polymorphisms. No DNA methylation polymorphisms were detected in conventionally propagated banana plants. These results demonstrated the usefulness of MSAP to detect DNA methylation events in micropropagated banana plants and indicate that DNA methylation polymorphisms are associated with micropropagation.

17O NMR parameters of some substituted benzyl ethers components: Ab initio study

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Mahdi Rezaei Sameti

2016-09-01

Full Text Available The 17O NMR chemical shielding tensors and chemical shift for a set of substituted benzyl ethers derivatives containing (methyl, ethyl, isopropyl, t-butyl, brome and lithium have been calculated. The molecular structures were fully optimized using B3LYP/6-31G(d,p. The calculation of the 17O shielding tensors employed the GAUSSIAN 98 implementation of the gauge-including atomic orbital (GIAO and continuous set of gauge transformations (CSGT by using 6-31G (d,p, 6-31++G(d,p and 6-311++G(d,p basis set methods at density functional levels of theories (DFT. The values determined using the GIAO and CSGT were found to give a good agreement with the experimental chemical shielding.

Preparation and characterization of polymer blend based on sulfonated poly (ether ether ketone) and polyetherimide (SPEEK/PEI) as proton exchange membranes for fuel cells

Energy Technology Data Exchange (ETDEWEB)

Hashim, Nordiana; Ali, Ab Malik Marwan [Ionic Material and Devices Research Laboratory, Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Lepit, Ajis; Rasmidi, Rosfayanti [Faculty of Applied Sciences, Universiti Teknologi MARA Sabah, Beg Berkunci 71, 88997 Kota Kinabalu (Malaysia); Subban, Ri Hanum Yahaya [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Yahya, Muhd Zu Azhan [Faculty of Defence Science & Technology, Universiti Pertahanan Nasional Malaysia, 57000 Kuala Lumpur (Malaysia)

2015-08-28

Blends of sulfonated poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared in five different weight ratios using N-methyl-2-pyrrolidone (NMP) as solvent by the solution cast technique. The degree of sulfonation (DS) of the sulfonated PEEK was determined from deuterated dimethyl sulfoxide (DMSO-d{sub 6}) solution of the purified polymer using {sup 1}H NMR method. The properties studied in the present investigation includes conductivity, water uptake, thermal stability and structure analysis of pure SPEEK as well as SPEEK-PEI polymer blend membranes. The experimental results show that the conductivity of the membranes increased with increase in temperature from 30 to 80°C, except for that of pure SPEEK membrane which increased with temperature from 30 to 60°C while its conductivity decreased with increasing temperature from 60 to 80°C. The conductivity of 70wt.%SPEEK-30wt.%PEI blend membrane at 80% relative humidity (RH) is found to be 1.361 × 10{sup −3} Scm{sup −1} at 30°C and 3.383 × 10{sup −3} Scm{sup −1} at 80°C respectively. It was also found that water uptake and thermal stability of the membranes slightly improved upon blending with PEI. Structure analysis was carried out using Fourier Transform Infrared (FTIR) spectroscopy which revealed considerable interactions between sulfonic acid group of SPEEK and imide groups of PEI. Modification of SPEEK by blending with PEI shows good potential for improving the electrical and physical properties of proton exchange membranes.

Rearrangements of Cycloalkenyl Aryl Ethers

Directory of Open Access Journals (Sweden)

Mercedesz Törincsi

2016-04-01

Full Text Available Rearrangement reactions of cycloalkenyl phenol and naphthyl ethers and the acid-catalyzed cyclization of the resulting product were investigated. Claisen rearrangement afforded 2-substituted phenol and naphthol derivatives. Combined Claisen and Cope rearrangement resulted in the formation of 4-substituted phenol and naphthol derivatives. In the case of cycloocthylphenyl ether the consecutive Claisen and Cope rearrangements were followed by an alkyl migration. The mechanism of this novel rearrangement reaction is also discussed.

Ether: Bitcoin's competitor or ally?

OpenAIRE

Bouoiyour, Jamal; Selmi, Refk

2017-01-01

Although Bitcoin has long been dominant in the crypto scene, it is certainly not alone. Ether is another cryptocurrency related project that has attracted an intensive attention because of its additional features. This study seeks to test whether these cryptocurrencies differ in terms of their volatile and speculative behaviors, hedge, safe haven and risk diversification properties. Using different econometric techniques, we show that a) Bitcoin and Ether are volatile and relatively more resp...

Use of experimental design for the purge-and-trap-gas chromatography-mass spectrometry determination of methyl tert.-butyl ether, tert.-butyl alcohol and BTEX in groundwater at trace level.

Science.gov (United States)

Bianchi, F; Careri, M; Marengo, E; Musci, M

2002-10-25

An efficient method for the simultaneous determination of methyl tert.-butyl ether, tert.-butyl alcohol, benzene, toluene, ethylbenzene and xylene isomers in groundwater by purge-and-trap-gas chromatography-mass spectrometry was developed and validated. Experimental design was used to investigate the effects of temperature of extraction, time of extraction and percentage of salt added to the water samples. Regression models and desirability functions were applied to find the experimental conditions providing the highest global extraction yield. Validation was carried out in terms of limits of detection (LOD), limits of quantitation (LOQ), linearity and precision. LOD values ranging from 2.6 to 23 ng l(-1) were achieved, whereas linearity was statistically verified over two orders of magnitude for each compound. Precision was evaluated testing two concentration levels. Good results were obtained both in terms of intra-day repeatability and intermediate precision: RSD% lower than 4.5% at the highest concentration and lower than 13% at the lowest one were calculated for intra-day repeatability. A groundwater sample suspected of contamination by leaking underground petroleum storage tanks was analysed and some of the analytes were detected and quantitated.

Catalytic hydroprocessing of lignin β-O-4 ether bond model compound phenethyl phenyl ether over ruthenium catalysts

NARCIS (Netherlands)

Gomez-Monedero, B.; Faria, J.; Bimbela, F.; Ruiz, M.P.

2017-01-01

The catalytic hydroprocessing of phenethyl phenyl ether (PPE), a model compound of one of the most significant ether linkages within lignin structure, β-O-4, has been studied. Reactions were carried out using two ruthenium-based catalysts, supported on different materials: 3.8 wt.% Ru/C and 3.9 wt.%

Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use

Directory of Open Access Journals (Sweden)

Denny Joseph Manual Kollareth

2018-03-01

Full Text Available Radiolabeled cholesteryl ethers are widely used as non-metabolizable tracers for lipoproteins and lipid emulsions in a variety of in vitro and in vivo experiments. Since cholesteryl ethers do not leave cells after uptake and are not hydrolyzed by mammalian cellular enzymes, these compounds can act as markers for cumulative cell uptakes of labeled particles. We have employed [3H]cholesteryl oleoyl ether to study the uptake and distribution of triglyceride-rich emulsion particles on animal models. However, questionable unexpected results compelled us to analyze the stability of these ethers. We tested the stability of two commercially available radiolabeled cholesteryl ethers - [3H]cholesteryl oleoyl ether and [3H]cholesteryl hexadecyl ether from different suppliers, employing in vitro, in vivo and chemical model systems. Our results show that, among the two cholesteryl ethers tested, one ether was hydrolyzed to free cholesterol in vitro, in vivo and chemically under alkaline hydrolyzing agent. Free cholesterol, unlike cholesteryl ether, can then re-enter the circulation leading to confounding results. The other ether was not hydrolyzed to free cholesterol and remained as a stable ether. Hence, radiolabeled cholesteryl ethers should be analyzed for biological stability before utilizing them for in vitro or in vivo experiments. Keywords: Cholesteryl ether, J774 A2 macrophages, Soy oil emulsion, Thin layer chromatography, triDHA emulsion

Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use.

Science.gov (United States)

Manual Kollareth, Denny Joseph; Chang, Chuchun L; Hansen, Inge H; Deckelbaum, Richard J

2018-03-01

Radiolabeled cholesteryl ethers are widely used as non-metabolizable tracers for lipoproteins and lipid emulsions in a variety of in vitro and in vivo experiments. Since cholesteryl ethers do not leave cells after uptake and are not hydrolyzed by mammalian cellular enzymes, these compounds can act as markers for cumulative cell uptakes of labeled particles. We have employed [ 3 H]cholesteryl oleoyl ether to study the uptake and distribution of triglyceride-rich emulsion particles on animal models. However, questionable unexpected results compelled us to analyze the stability of these ethers. We tested the stability of two commercially available radiolabeled cholesteryl ethers - [ 3 H]cholesteryl oleoyl ether and [ 3 H]cholesteryl hexadecyl ether from different suppliers, employing in vitro , in vivo and chemical model systems. Our results show that, among the two cholesteryl ethers tested, one ether was hydrolyzed to free cholesterol in vitro , in vivo and chemically under alkaline hydrolyzing agent. Free cholesterol, unlike cholesteryl ether, can then re-enter the circulation leading to confounding results. The other ether was not hydrolyzed to free cholesterol and remained as a stable ether. Hence, radiolabeled cholesteryl ethers should be analyzed for biological stability before utilizing them for in vitro or in vivo experiments.

Global Gridded Emission Inventories of Pentabrominated Diphenyl Ether (PeBDE)

Science.gov (United States)

Li, Yi-Fan; Tian, Chongguo; Yang, Meng; Jia, Hongliang; Ma, Jianmin; Li, Dacheng

2010-05-01

Polybrominated diphenyl ethers (PBDEs) are flame retardants widely used in many everyday products such as cars, furniture, textiles, and other electronic equipment. The commercial PBDEs have three major technical mixtures: penta-(PeBDE), octa-(OBDE) and decabromodiphenyl ethers (DeBDE). PeBDE is a mixture of several BDE congeners, such as BDE-47, -99, and -100, and has been included as a new member of persistent organic pollutants (POPs) under the 2009 Stockholm Convention. In order to produce gridded emission inventories of PeBDE on a global scale, information of production, consumption, emission, and physiochemical properties of PeBDE have been searched for published papers, government reports, and internet publications. A methodology to estimate the emissions of PeBDE has been developed and global gridded emission inventories of 2 major congener in PeBDE mixture, BDE-47 and -99, on a 1 degree by 1degree latitude/longitude resolution for 2005 have been compiled. Using these emission inventories as input data, the Canadian Model for Environmental Transport of Organochlorine Pesticides (CanMETOP) model was used to simulate the transport of these chemicals and their concentrations in air were calculated for the year of 2005. The modeled air concentration of BDE-47 and -99 were compared with the monitoring air concentrations of these two congeners in the same year obtained from renowned international/national monitoring programs, such as Global Atmospheric Passive Sampling (GAPS), the Integrated Atmospheric Deposition Network (IADN), and the Chinese POPs Soil and Air Monitoring Program (SAMP), and significant correlations between the modeled results and the monitoring data were found, indicating the high quality of the produced emission inventories of BDE-47 and -99. Keywords: Pentabrominated Diphenyl Ether (PeBDE), Emission Inventories, Global, Model

DNA Methylation and Methylation Polymorphism in Genetically Stable In vitro Regenerates of Jatropha curcas L. Using Methylation-Sensitive AFLP Markers.

Science.gov (United States)

Rathore, Mangal S; Jha, Bhavanath

2016-03-01

The present investigation aimed to evaluate the degree and pattern of DNA methylation using methylation-sensitive AFLP (MS-AFLP) markers in genetically stable in vitro regenerates of Jatropha curcas L.. The genetically stable in vitro regenerates were raised through direct organogenesis via enhanced axillary shoot bud proliferation (Protocol-1) and in vitro-derived leaf regeneration (Protocol-2). Ten selective combinations of MS-AFLP primers produced 462 and 477 MS-AFLP bands in Protocol-1 (P-1) and Protocol-2 (P-2) regenerates, respectively. In P-1 regenerates, 15.8-31.17 % DNA was found methylated with an average of 25.24 %. In P-2 regenerates, 15.93-32.7 % DNA was found methylated with an average of 24.11 %. Using MS-AFLP in P-1 and P-2 regenerates, 11.52-25.53 % and 13.33-25.47 % polymorphism in methylated DNA was reported, respectively. Compared to the mother plant, P-1 regenerates showed hyper-methylation while P-2 showed hypo-methylation. The results clearly indicated alternation in degree and pattern of DNA methylation; hence, epigenetic instability in the genetically stable in vitro regenerates of J. curcas, developed so far using two different regeneration systems and explants of two different origins. The homologous nucleotide fragments in genomes of P-1 and P-2 regenerates showing methylation re-patterning might be involved in immediate adaptive responses and developmental processes through differential regulation of transcriptome under in vitro conditions.

A Facile and Efficient Synthesis of Diaryl Amines or Ethers under Microwave Irradiation at Presence of KF/Al2O3 without Solvent and Their Anti-Fungal Biological Activities against Six Phytopathogens

Directory of Open Access Journals (Sweden)

Tao Zhang

2013-09-01

Full Text Available A series of diaryl amines, ethers and thioethers were synthesized under microwave irradiation efficiently at presence of KF/Al2O3 in 83%–96% yields without any solvent. The salient characters of this method lie in short reaction time, high yields, general applicability to substrates and simple workup procedure. At the same time, their antifungal biological activities against six phytopathogen were evaluated. Most of the compounds (3b, 3c, 3g–o are more potent than thiophannate-methyl against to Magnaporthe oryzae. This implies that diaryl amine or ether moiety may be helpful in finding a fungicide against Magnaporthe oryzae.

Electron beam irradiation of poly(perfluoro ethers): Identification of gaseous products as a result of main chain scission

International Nuclear Information System (INIS)

Pacansky, J.; Waltman, R.J.

1991-01-01

Several poly(perfluoro ethers) are exposed to electron beams to study the mechanism for main chain scission. Electron beam exposures were performed with the viscous poly(perfluoro ethers) under argon gas, and also at 9 K under vacuum, to determine mechanistic details for the chemical degradation. Here the authors report that, after main chain scission of the bulk poly(perfluoro ethers), sample weight loss is observed concomitant with evolution of gaseous products. Since this suggests that some unzipping of the polymer chain occurs, the products were identified and, most importantly, the efficiency for their formation was determined in terms of G values, and compared to known G values for main chain scission. The results show that COF 2 is the major gaseous product produced from unbranched ethers while CF 4 and COF 2 are the major products from branched polymers. The gaseous products were also exposed to the high-energy electron beam and the G values for decomposition are given

Novel Naphthalene Based Lariat-Type Crown Ethers Using Direct Single Electron Transfer Photochemical Strategy

International Nuclear Information System (INIS)

Park, Hea Jung; Sung, Nam Kyung; Kim, Su Rhan; Kim, Su Rhan; Ahn, So Hyun; Yoon, Ung Chan; Cho, Dae Won; Mariano, Patrick S.

2013-01-01

This study explored a direct SET-photochemical strategy to construct a new family of thioene conjugated-naphthalamide fluorophore based lariat-crown ethers which show strong binding properties towards heavy metal ions. Irradiations of designed nitrogen branched (trimethylsilyl)methylthio-terminated polyethylenoxy-tethered naphthalimides in acidic methanol solutions have led to highly efficient photocyclization reactions to generate naphthalamide based lariat type thiadiazacrown ethers directly in chemo- and regio-selective manners which undergo very facile secondary dehydration reactions during separation processes to produce their corresponding amidoenethio ether cyclic products tethered with electron donating diethyleneoxy- and diethyenethio-side arm chains. Fluorescence and metal cation binding properties of the lariat type enamidothio products were examined. The photocyclized amidoenethio products, thioene conjugated naphthalamide fluorophore containing lariat-thiadiazacrowns exhibited strong fluorescence emissions in region of 330-450 nm along with intramolecular exciplex emissions in region of 450-560 nm with their maxima at 508 nm. Divalent cation Hg 2+ and Pb 2+ showed strong binding to sulfur atom(s) in side arm chain and atoms in enethiadiazacrown ether rings which led to significant enhancement of fluorescence from its chromophore singlet excited state and concomitant quenching of exciplex emission. The dual fluorescence emission responses towards divalent cations might provide a new guide for design and development of fluorescence sensors for detecting those metals

Effective utilization of B20 blend with diethyl ether and ethanol as oxygenated additives

Directory of Open Access Journals (Sweden)

Upadrasta-Satya Vara-Prasad

2011-01-01

Full Text Available In the recent times' fatty acid methyl ester popularly called as biodiesel has become more prominent alternate fuel for compression ignition engines based on a single fuel concept. Since, use of neat biodiesel on a large scale is raising certain difficulties and is being adopted in a blended form with petro-diesel fuel and B20 blend has become standardized. However, the HC and NOx emissions of B20 are still on the higher side. Present work aims at experimental evaluation of a single cylinder water-cooled diesel engine by adopting various proportions of ethanol and diethyl ether blends in order to improve performance and emission characteristics of B20 blend. Besides employing different amounts of ethanol and diethyl ether, simultaneous influence of injector nozzle hole size and fuel injection pressure are also investigated to arrive at an optimum configuration. Brake specific fuel consumption and hydrocarbon emissions values are lower with B20 and DEE 5 whereas B20 with DEE15 yielded lower NOx emissions. It is observed that addition of oxygenates have improved the combustion process and lower emissions are obtained. The present investigation revealed that blends with oxygenated additives having higher Cetane rating are superior to neat blend.

Numerical investigation on the effect of injection pressure on the internal flow characteristics for diethyl ether, dimethyl ether and diesel fuel injectors using CFD

Directory of Open Access Journals (Sweden)

Vijayakumar Thulasi

2011-01-01

Full Text Available The spray characteristics of the diesel fuel are greatly affected by the cavitation formed inside the injector due to the high pressure differential across the nozzle. Many researchers across the globe are exploring the potential of using diethyl ether and dimethyl ether as an alternate for diesel fuel to meet the strict emission norms. Due to the variation in the fuel properties the internal flow characteristics in injectors for ether fuels are expected to be different from that of the diesel fuel. In this paper computational technique is used to study and compare the internal flow characteristics of diethyl ether, dimethyl ether and diesel fuel. The two phase flow model considering the fuel as a mixture of liquid and vapor is adopted for the simulation study. The injection pressure is varied from 100 to 400 bar and the flow characteristics of all three fuels are simulated and compared. Results indicate that all three fuels have distinct cavitating patterns owing to different property values. The dimethyl ether is found to be more cavitating than diesel and diethyl ether fuels as expected. The mass of fuel injected are found to be decreasing for the ether fuels when compared with diesel fuel at all injection pressures.

AIRBORNE POLYBROMINATED DIPHENYL ETHERS IN A COMPUTER CLASSROOM OF COLLEGE IN TAIWAN

Directory of Open Access Journals (Sweden)

F. H. Chang ، C. R. Yang ، C. Y. Tsai ، W. C. Lin

2009-04-01

Full Text Available This study characterized the airborne exposure of students to thirty polybrominated diphenyl ether congeners inside and outside a computer classroom in a southern Taiwan college. Arithmetic mean values of total indoor and outdoor polybrominated diphenyl ether concentrations were 125.0 pg/m3 (89.8 to 203.9 pg/m3 and 110.3 pg/m3 (83.5 to 157.0 pg/m3, respectively. Total indoor polybrominated diphenyl ether concentrations were one order of magnitude lower than those detected in homes in Birmingham, United Kingdom and in Ottawa, Canada but were several times higher than those measured in the ambient air in Ottawa, Canada and from the Bohai Sea to the Arctic. The five highest indoor concentrations of polybrominated diphenyl ether congeners were decabromodiphenyl ether (23.0 pg/m3, 4,4’-dibromodiphenyl ether (15.9 pg/m3, 2,2’,3,4,4’,5,5’,6-octabromodiphenyl ether (10.6 pg/m3, 2,4-dibromodiphenyl ether (10.3 pg/m3 and 2,2’,3,4,4’,5’,6-heptabromodiphenyl ether (10.0 pg/m3. Although indoor and outdoor total polybrominated diphenyl ether concentrations did not significantly differ, the indoor concentrations of 2,4-dibromodiphenyl ether, 2,2’,4-tribromodiphenyl ether, 2,4,4’-tribromodiphenyl ether, 2,2’,4,5’-tetrabromodiphenyl ether and 2,3’,4’,6-tetrabromodiphenyl ether were significantly higher than their outdoor concentrations. This study suggests the following measures: 1 to increase the air exchange rate and open classroom doors and windows for several minutes before classes to reduce indoor PBDE concentrations; 2 to reduce polybrominated diphenyl ether emissions from new devices, it’s better to use computer-related products that meet the Restriction of Hazardous Substances Directive adopted by the European Union.

Thermal Stability of Sulfonated Poly(Ether Ether Ketone) Films: on the Role of Protodesulfonation

OpenAIRE

Koziara, Beata; Kappert, Emiel; Ogieglo, Wojciech; Nijmeijer, Dorothea C.; Hempenius, Mark A.; Benes, Nieck Edwin

2016-01-01

Thin film and bulk, sulfonated poly(ether ether ketone) (SPEEK) have been subjected to a thermal treatment at 160–250 °C for up to 15 h. Exposing the films to 160 °C already causes partial desulfonation, and heating to temperatures exceeding 200 °C results in increased conjugation in the material, most likely via a slight cross-linking by H-substitution. It is well-known that the sulfonate proton plays a major role in the desulfonation reactions, and exchanging the protons with other cations ...

Experimental vapor pressures (from 1 Pa to 100 kPa) of six saturated Fatty Acid Methyl Esters (FAMEs): Methyl hexanoate, methyl octanoate, methyl decanoate, methyl dodecanoate, methyl tetradecanoate and methyl hexadecanoate

International Nuclear Information System (INIS)

Sahraoui, Lakhdar; Khimeche, Kamel; Dahmani, Abdallah; Mokbel, Ilham; Jose, Jacques

2016-01-01

Highlight: • Vapor-liquid equilibria, Enthalpy of Vaporization, saturated Fatty Acid Methyl Ester. - Abstract: Vapor pressures of six saturated Fatty Acid Methyl Esters (FAMEs), methyl hexanoate (or methyl caproate), methyl octanoate (or methyl caprylate), Methyl decanoate (or methyl caprate), methyl dodecanoate (or methyl laurate), methyl tetradecanoate (or methyl myristate), and methyl hexadecanoate (or methyl palmitate) were measured from 1 Pa to 100 kPa and at temperature range between 262 and 453 K using a static apparatus. The experimental data (P-T) were compared with the available literature data.

α-Diazo oxime ethers for N-heterocycle synthesis.

Science.gov (United States)

Choi, Subin; Ha, Sujin; Park, Cheol-Min

2017-06-01

This Feature Article introduces the preparation and synthetic utility of α-diazo oxime ethers. α-Oximino carbenes are useful synthons for N-heterocycles, and can be easily prepared from α-diazo oxime ethers as precursors. We begin with the preparation of α-diazo oxime ethers and their application in [3+2] cycloaddition. It turns out that the nature of metals bound to carbenes plays a crucial role in modulating the reactivity of α-oximino carbenes, in which copper carbenes smoothly react with enamines, whereas the less reactive enol ethers and nitriles require gold carbenes. In Section 3.2, a discussion on N-O and C-H bond activation is presented. Carbenes derived from diazo oxime ethers show unique reactivity towards N-O and C-H bond activation, in which the proximity of the two functionalities, carbene and oxime ether, dictates the preferred reaction pathways toward pyridines, pyrroles, and 2H-azirines. In Section 3.3, the development of tandem reactions based on α-diazo oxime ethers is discussed. The nature of carbenes in which whether free carbenes or metal complexes are involved dissects the pathway and forms different types of 2H-azirines. The 2H-azirine formation turned out to be an excellent platform for the tandem synthesis of N-heterocycles including pyrroles and pyridines. In the last section, we describe the electrophilic activation of 2H-azirines with vinyl carbenes and oximino carbenes. The resulting azirinium species undergo rapid ring expansion rearrangements to form pyridines and pyrazines.

Novel proton exchange membranes based on structure-optimized poly(ether ether ketone ketone)s and nanocrystalline cellulose

Science.gov (United States)

Ni, Chuangjiang; Wei, Yingcong; Zhao, Qi; Liu, Baijun; Sun, Zhaoyan; Gu, Yan; Zhang, Mingyao; Hu, Wei

2018-03-01

Two sulfonated fluorenyl-containing poly(ether ether ketone ketone)s (SFPEEKKs) were synthesized as the matrix of composite proton exchange membranes by directly sulfonating copolymer precursors comprising non-sulfonatable fluorinated segments and sulfonatable fluorenyl-containing segments. Surface-modified nanocrystalline cellulose (NCC) was produced as the "performance-enhancing" filler by treating the microcrystalline cellulose with acid. Two families of SFPEEKK/NCC nanocomposite membranes with various NCC contents were prepared via a solution-casting procedure. Results revealed that the insertion of NCC at a suitable ratio could greatly enhance the proton conductivity of the pristine membranes. For example, the proton conductivity of SFPEEKK-60/NCC-4 (SFPEEKK with 60% fluorenyl segments in the repeating unit, and inserted with 4% NCC) composite membrane was as high as 0.245 S cm-1 at 90 °C, which was 61.2% higher than that of the corresponding pure SFPEEKK-60 membrane. This effect could be attributed to the formation of hydrogen bond networks and proton conduction paths through the interaction between -SO3H/-OH groups on the surface of NCC particles and -SO3H groups on the SFPEEKK backbones. Furthermore, the chemically modified NCC filler and the optimized chemical structure of the SFPEEKK matrix also provided good dimensional stability and mechanical properties of the obtained nanocomposites. In conclusion, these novel nanocomposites can be promising proton exchange membranes for fuel cells at moderate temperatures.

The Effect of Time dealumination and Solvent Concentration in Synthesis of Zeolite Catalyst and Catalytic Test for DiEthyl Ether Production Process

International Nuclear Information System (INIS)

Widayat; Roesyadi, A.; Rachimoellah, M.

2009-01-01

Ethanol is an alternative energy, but its has three distinct disadvantages as a transportation fuel. Its availability is currently limited, and it has a lower volumetric heating value and a lower Reid vapour pressure (RVP) than gasoline. This paper focuses for this disadvantages and to solve this problem can do with converts ethanol to DiEthyl Ether product. This research produced DiEthyl Ether by ethanol dehydration process with zeolite as catalyst. The catalyst synthesis from natural material from District Gunung Kidul, Indonesia. The catalyst produced with dealumination, neutralization, drying and calcination processes. The zeolite catalyst was analysed of Si/Al, X-ray Diffraction and specific surface area. The catalyst product then used for ethanol dehydration to produce DiEthyl Ether. The results shown the biggest surface area is 184,52 m 2 /gram at catalyst production at 10 hours for time dealumination. The crystallite of catalyst product is similar like shown at diffractogram of XRD analysis. The ratio Si/Al biggest is 313.7 that obtaining at catalyst production with 7 hours for time dealumination. The catalytic test use fixed bed reactor with 1 inci diameter and ethanol fermentation both as feed. The operation condition is 150 deg. C at temperature and atmosphere pressure. The compounds product in liquid phase are diethyl ether, methanol and water.

Strain of Fusarium oxysporum Isolated From Almond Hulls Produces Styrene and 7-Methyl-1,3,5-Cyclooctatriene as the Principal Volatile Components

Science.gov (United States)

An isolated strain of Fusarium oxysporum from the hulls of Prunus dulcis (sweet almond) was found to produce relatively large quantities of the hydrocarbons styrene and three isomers of 7-methyl-1,3,5-cyclooctatriene (MCOT). Production of styrene and MCOT was reproduced on small scale using potato d...

Dimethyl ether as a drift-chamber gas

International Nuclear Information System (INIS)

Bari, G.; Basile, M.; Bonvicini, G.; Cara Romeo, G.; Casaccia, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; D'Ali, G.; Del Papa, C.; Focardi, S.; Iacobucci, G.; Maccarrone, G.; Massam, T.; Motta, F.; Nania, R.; Palmonari, F.; Prisco, G.; Sartorelli, G.; Susinno, G.; Votano, L.; Zichichi, A.; Istituto Nazionale di Fisica Nucleare, Bologna; European Organization for Nuclear Research, Geneva; Istituto Nazionale di Fisica Nucleare, Frascati; Michigan Univ., Ann Arbor; Palermo Univ.

1986-01-01

We have continued the testing of dimethyl ether as a drift-chamber gas in order to improve the understanding of its properties. In particular, we report on measurement accuracy, on systematic effects, and some preliminary data on the ageing of a detector filled with dimethyl ether. (orig.)

Process for making propenyl ethers and photopolymerizable compositions containing them

Science.gov (United States)

Crivello, James V.

1996-01-01

Propenyl ether monomers of formula V A(OCH.dbd.CHCH.sub.3).sub.n wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of formula V together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

RATE CONSTANTS FOR THE REACTIONS OF OH RADICALS AND CL ATOMS WITH DI-N-PROPYL ETHER AND DI-N-BUTYL ETHER AND THEIR DEUTERATED ANALOGS. (R825252)

Science.gov (United States)

Using relative rate methods, rate constants for the gas-phase reactions of OH radicals and Cl atoms with di-n-propyl ether, di-n-propyl ether-d14, di-n-butyl ether and di-n-butyl ether-d18 have been measured at 296 ? 2 K and atmos...

The anthraquinones rubiadin and its 1-methyl ether isolated from Heterophyllaea pustulata reduces Candida tropicalis biofilms formation.

Science.gov (United States)

Marioni, Juliana; da Silva, María Angel; Cabrera, José Luis; Montoya, Susana C Núñez; Paraje, María Gabriela

2016-11-15

Candida tropicalis is increasingly becoming among the most commonly isolated pathogens causing fungal infections with an important biofilm-forming capacity. This study addresses the antifungal effect of rubiadin (AQ1) and rubiadin 1-methyl ether (AQ2), two photosensitizing anthraquinones (AQs) isolated from Heterophyllaea pustulata, against C. tropicalis biofilms, by studying the cellular stress and antioxidant response in two experimental conditions: darkness and irradiation. The combination with Amphotericin B (AmB) was assayed to evaluate the synergic effect. Biofilms of clinical isolates and reference strain of Candida tropicalis were treated with AQs (AQ1 or AQ2) and/or AmB, and the biofilms depletion was studied by crystal violet and confocal scanning laser microscopy (CSLM). The oxidant metabolites production and the response of antioxidant defense system were also evaluated under dark and irradiation conditions, being the light a trigger for photo-activation of the AQs. The Reactive Oxygen Species (ROS) were detected by the reduction of Nitro Blue Tetrazolium test, and Reactive Nitrogen Intermediates (RNI) by the Griess assay. ROS accumulation was also detected inside biofilms by using 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) probe, which was visualized by CSLM. Superoxide dismutase (SOD) activity and the total antioxidant capacity of biofilms were measured by spectrophotometric methods. The minimun inhibitory concentration for sessile cells (SMIC) was determined for each AQs and AmB. The fractional inhibitory concentration index (FICI) was calculated for the combinations of each AQ with AmB by the checkerboard microdilution method. Biofilm reduction of both strains was more effective with AQ1 than with AQ2. The antifungal effect was mediated by an oxidative and nitrosative stress under irradiation, with a significant accumulation of endogenous ROS detected by CSLM and an increase in the SOD activity. Thus, the prooxidant-antioxidant balance was

Selective crystallization of cations with crown ethers

International Nuclear Information System (INIS)

Heffels, Dennis Egidius

2014-01-01

The aim of this work was to study the selectivity and preferences of the incorporation of differently sized cations in the cavities of various crown ethers and the characterization of the resulting compounds. The coordination preferences of crown ethers with different cavities have long been known, and the impact of other effects on the structure formation have increasingly become the focus of attention. In this work a comparative overview of the coordination preferences depending on various factors was undertaken. The focus was mainly on the variation of the cavity of the crown ether in the presence of differently sized cations. In addition, the effects of the solvent and differently coordinating anions have been investigated. Within the framework of this work, basic coordination preferences could be detected with rare earth nitrates, which are affected particularly by the choice of the solvent. The formation of different types of structures could be controlled by varying the conditions such that the incorporation of the cation in the cavity of the crown ether was influenced and the formation of a particular type of structure can be influenced partly by the choice of solvent. In this case no direct preferences for the incorporation into the cavity of the crown ether in relation to the cation size were observed for rare earth cations. However, the coordination of the crown ether leads in each case - for lanthanides - to rather high coordination numbers. A total of five new rare earth complexes and two structural variants could be observed with crown ethers. In the study of the selectivity of the incorporation into the cavity, known structures were also reproduced and further structures were characterized but the crystal structures not entirely solved. With the use of monovalent cations such as potassium, lithium or silver a total of nine new compounds could be synthesized, while no clear preferences for the incorporation of certain cations were detected. The

A practical and improved synthesis of (3S,5S)-3-[(tert-butyloxycarbonyl)methyl]- 5-[(methanesulfonyloxy)methyl]-2- pyrrolidinone.

Science.gov (United States)

Yee, Nathan K; Dong, Yong; Kapadia, Suresh R; Song, Jinhua J

2002-11-29

A practical and improved synthesis of (3S,5S)-3-[(tert-butyloxycarbonyl)methyl]-5-[(methanesulfonyloxy)methyl]-2-pyrrolidinone (1) is described. The key transformations involve a highly efficient reaction sequence consisting of ethoxycarbonylation, alkylation, hydrolysis, and decarboxylation to produce compound 10. The process described herein is practical, robust, and cost-effective, and it has been successfully implemented in a pilot plant to produce a multikilogram quantity of mesylate 1.

Microwave-assisted pyrolysis of methyl ricinoleate for continuous production of undecylenic acid methyl ester (UAME).

Science.gov (United States)

Nie, Yong; Duan, Ying; Gong, Ruchao; Yu, Shangzhi; Lu, Meizhen; Yu, Fengwen; Ji, Jianbing

2015-06-01

Undecylenic acid methyl ester (UAME) was continuously produced from methyl ricinoleate using a microwave-assisted pyrolysis system with atomization feeding. The UAME yield of 77 wt.% was obtained at 500°C using SiC as the microwave absorbent and heating medium. The methyl ricinoleate conversion and UAME yield from microwave-assisted pyrolysis process were higher than those from conventional pyrolysis. The effect of temperature on the pyrolysis process was also investigated. The methyl ricinoleate conversion increased but the cracking liquid yield decreased when the temperature increased from 460°C to 560°C. The maximum UAME yield was obtained at the temperature of 500°C. Copyright © 2015 Elsevier Ltd. All rights reserved.

Radiation-induced transformations of cellulose ethers

International Nuclear Information System (INIS)

Nud'ga, L.A.; Petropavlovskii, G.S.; Plisko, E.A.; Isakova, O.V.; Ershov, B.G.

1988-01-01

The purpose of this investigation was to study the transformation which take place under the action of γ-radiation in a number of cellulose ethers containing both saturated (carboxymethyl, hydroxyethyl) and unsaturated (allyl, methacryloyl) groups. Irradiation was carried out on a 60 Co unit in air at 77 and 300 K; the dose rate was 37 and 50 kGy/h respectively. The EPR spectra of γ-irradiated hydroxyethyl- and allylhydroxyethylcelluloses are identical. Under the action of γ-radiation extensive changes took place in cellulose ethers which are exhibited in degradation or the formation of three-dimensional structures and are accompanied by a change in the functional composition. The efficiency in the formation of radicals and their localization are determined by the nature and number of substituents in the cellulose ethers

Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)—the effect of biomolecular ligands to balance cell adhesion and stimulated detachment

International Nuclear Information System (INIS)

Teichmann, Juliane; Valtink, Monika; Funk, Richard H W; Engelmann, Katrin; Nitschke, Mirko; Pette, Dagmar; Gramm, Stefan; Werner, Carsten; Härtel, Frauke V; Noll, Thomas

2015-01-01

Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly(N-isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na + /K + -ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro. The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty. (paper)

Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)—the effect of biomolecular ligands to balance cell adhesion and stimulated detachment

Science.gov (United States)

Teichmann, Juliane; Nitschke, Mirko; Pette, Dagmar; Valtink, Monika; Gramm, Stefan; Härtel, Frauke V; Noll, Thomas; Funk, Richard H W; Engelmann, Katrin; Werner, Carsten

2015-01-01

Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly(N-isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na+/K+-ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro. The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty. PMID:27877823

Contribution to the study by infrared spectroscopy of addition compounds of boron fluorides and ethers-oxides or organic sulphides; Contribution a l'etude par spectroscopie infrarouge des composes d'addition des fluorures de bore et des ethers-oxydes ou des sulfures organiques

Energy Technology Data Exchange (ETDEWEB)

Le Calve, Jacques

1964-03-09

This research thesis reports the study of complexes formed with boron fluoride and ethers or organic sulphides. In a first part, the author recalls vibration modes of free boron fluoride and of this compound in a complex. In the next parts, he reports the analysis of infrared spectra of groups present in addition compounds (between 400 and 1500 cm{sup -1}). He discusses spectrum modifications of electron donors by formation of a coordination bound. Experimental conditions are presented in appendix [French] Nous avons enregistre les spectres infrarouges de 400 a 4000 cm{sup -1} des composes d'addition du fluorure de bore et des oxydes de methyle, d'ethyle et du tetrahydrofuranne a l'etat gazeux, a l'etat liquide et a - 180 deg. a l'etat solide. Nous avons egalement etudie les complexes du fluorure de bore et des sulfures de methyle, d'ethyle et du tetrahydrothiophene a l'etat liquide. Le groupement c-c-OBF{sub 3} des trois composes des ethers avait fait l'objet d'une analyse tres recente que nous avons discutee. La comparaison des spectres et leur evolution en fonction de l'etat physique nous a notamment permis de mettre en evidence un couplage des vibrations de valence symetrique ν{sub s}(BF{sub 3}) et ν(OB) avec celles de meme symetrie du squelette de l'ether, en particulier la vibration ν{sub s}(COC). Ce couplage rend illusoires les correlations qui avaient ete proposees entre la basicite du donneur et la position d'une bande attribuee hativement a la vibration ν{sub s}(BF{sub 3}). Pour les composes d'addition des sulfures, nous avons attribue les principales vibrations du groupement C-C-SBF{sub 3}. La vibration de valence degeneree ν{sub s}(BF{sub 3}) apparait vers 1180 cm{sup -1}. Les vibrations de valence symetriques ν{sub s}(BF{sub 3}) et ν(SB) sont couplees et se manifestent dans les spectres par deux bandes vers 800 et 600 cm{sup -1}. Enfin, une absorption vers 460 cm{sup -1} correspond a l'une des vibrations de deformation symetrique ou degeneree �

Measurement of critical temperatures and critical pressures for binary mixtures of methyl tert-butyl ether (MTBE) + alcohol and MTBE + alkane

International Nuclear Information System (INIS)

Han, Kewei; Xia, Shuqian; Ma, Peisheng; Yan, Fangyou; Liu, Tao

2013-01-01

Highlights: • The critical properties of seven binary mixtures related to gasoline were measured. • The critical properties of the five systems containing MTBE were reported for the first time. • Binary interaction parameters were fitted by experimental data using PR EOS with Wong–Sandler mixing rule. • Redlich–Kister equation was used to correlate the experimental data. -- Abstract: A set of high-pressure view apparatus was designed for determining the critical properties of chemicals. In order to check the reliability of the apparatus, the critical temperatures (T c ) and critical pressures (P c ) of pure n-heptane, cyclohexane, methanol, ethanol, 1-propanol, methyl tert-butyl ether (MTBE), and binary mixture n-hexane + ethanol were measured. The experimental data were in good agreement with the literature data, which proves the reliability of the apparatus used in the work. The critical temperatures and critical pressures of five binary mixtures containing gasoline additive (MTBE + n-heptane, MTBE + cyclohexane, MTBE + methanol, MTBE + ethanol, MTBE + 1-propanol) were measured using the high-pressure view cell with visual observation. The critical temperatures and critical pressures for the five binary mixtures were all reported for the first time. In addition, the critical temperatures and critical pressures of the binary mixture n-heptane + cyclohexane (two of main components in gasoline) were also measured. All the critical lines for the mixtures studied are continuous which connect the critical points of the two pure components, indicating their phase diagrams belong to type I proposed by Scott and van Konynenburg. The critical points of these systems were calculated by the Peng–Robinson equation of state with the Wong–Sandler mixing rule. This model could calculate the critical properties of the mixtures well with the binary interaction parameter k ij obtained by fitting the experimental critical data. And the experimental data were all

On the ether-like Lorentz-breaking actions

International Nuclear Information System (INIS)

Petrov, A.Yu; Nascimento, J.R.; Gomes, M.; Silva, A. J. da

2011-01-01

We demonstrate the generation of the CPT-even, ether-like Lorentz-breaking actions for the scalar and electro-magnetic fields via their appropriate Lorentz-breaking coupling to spinor fields in three, four and five space-time dimensions. Besides, we show that the ether-like terms for the spinor field also can be generated as a consequence of the same couplings. The key result which will be presented here is the finiteness of the ether-like term for the electromagnetic field not only in three and five space-time dimensions where it is natural due to known effects of the dimensional regularization but also in four space-time dimensions. Moreover, we present the calculation of the last result within different calculational schemes and conclude that the result for the four-dimensional ether-like term for the electromagnetic field essentially depending on the calculation scheme, similarly to the result for the Carroll-Field-Jackiw (CFJ) term which probably signalizes a possibility for arising of a new anomaly. Also we discuss the dispersion relations in the theories with ether-like Lorentz-breaking terms which allows to discuss the consistency of the Lorentz-breaking modified theories for different (space-like or time-like) Lorentz-breaking vectors and find the tree-level effective (Breit) potential for fermion scattering and the one-loop effective potential corresponding to the action of the scalar field. (author)

Tissue engineering of bovine articular cartilage within porous poly(ether ester) copolymer scaffolds with different structures

NARCIS (Netherlands)

Mahmood, Tahir A.; Shastri, V. Prasad; van Blitterswijk, Clemens; Langer, Robert; Riesle, J.U.

2005-01-01

The potential of porous poly(ether ester) scaffolds made from poly(ethylene glycol) terephthalate: poly(butylene terephthalate) (PEGT:PBT) block copolymers produced by various methods to enable cartilaginous tissue formation in vitro was studied. Scaffolds were fabricated by two different processes:

Novel Naphthalene Based Lariat-Type Crown Ethers Using Direct Single Electron Transfer Photochemical Strategy

Energy Technology Data Exchange (ETDEWEB)

Park, Hea Jung; Sung, Nam Kyung; Kim, Su Rhan; Kim, Su Rhan; Ahn, So Hyun; Yoon, Ung Chan [Pusan National Univ., Busan (Korea, Republic of); Cho, Dae Won [Yeungnam Univ., Geoungsan (Korea, Republic of); Mariano, Patrick S. [Univ. of New Mexico, Albuquerque (United States)

2013-12-15

This study explored a direct SET-photochemical strategy to construct a new family of thioene conjugated-naphthalamide fluorophore based lariat-crown ethers which show strong binding properties towards heavy metal ions. Irradiations of designed nitrogen branched (trimethylsilyl)methylthio-terminated polyethylenoxy-tethered naphthalimides in acidic methanol solutions have led to highly efficient photocyclization reactions to generate naphthalamide based lariat type thiadiazacrown ethers directly in chemo- and regio-selective manners which undergo very facile secondary dehydration reactions during separation processes to produce their corresponding amidoenethio ether cyclic products tethered with electron donating diethyleneoxy- and diethyenethio-side arm chains. Fluorescence and metal cation binding properties of the lariat type enamidothio products were examined. The photocyclized amidoenethio products, thioene conjugated naphthalamide fluorophore containing lariat-thiadiazacrowns exhibited strong fluorescence emissions in region of 330-450 nm along with intramolecular exciplex emissions in region of 450-560 nm with their maxima at 508 nm. Divalent cation Hg{sup 2+} and Pb{sup 2+} showed strong binding to sulfur atom(s) in side arm chain and atoms in enethiadiazacrown ether rings which led to significant enhancement of fluorescence from its chromophore singlet excited state and concomitant quenching of exciplex emission. The dual fluorescence emission responses towards divalent cations might provide a new guide for design and development of fluorescence sensors for detecting those metals.

Species and gender differences in the metabolism and distribution of tertiary amyl methyl ether in male and female rats and mice after inhalation exposure or gavage administration.

Science.gov (United States)

Sumner, Susan C J; Janszen, Derek B; Asgharian, Bahman; Moore, Timothy A; Parkinson, Horace D; Fennell, Timothy R

2003-01-01

Tertiary amyl methyl ether (TAME) is a gasoline fuel additive used to reduce emissions. Understanding the metabolism and distribution of TAME is needed to assess potential human health issues. The effect of dose level, duration of exposure and route of administration on the metabolism and distribution of TAME were investigated in male and female F344 rats and CD-1 mice following inhalation or gavage administration. By 48 h after exposure, >96% of the administered radioactivity was expired in air (16-71%) or eliminated in urine and feces (28-72%). Following inhalation exposure, mice had a two- to threefold greater relative uptake of [14C]TAME compared with rats. Metabolites were excreted in urine of rats and mice that are formed by glucuronide conjugation of tertiary amyl alcohol (TAA), oxidation of TAA to 2,3-dihydroxy-2-methylbutane and glucuronide conjugation of 2,3-dihydroxy-2-methylbutane. A saturation in the uptake and metabolism of TAME with increased exposure concentration was indicated by a decreased relative uptake of total [14C]TAME equivalents and an increase in the percentage expired as volatiles. A saturation of P-450 oxidation of TAA was indicated by a disproportional decrease of 2,3-dihydroxy-2-methylbutane and its glucuronide conjugate with increased exposure concentration. Copyright 2003 John Wiley & Sons, Ltd.

Sulfonated poly(ether ether ketone)/poly(vinyl alcohol) sensitizing system for solution photogeneration of small Ag, Au, and Cu crystallites.

Science.gov (United States)

Korchev, A S; Shulyak, T S; Slaten, B L; Gale, W F; Mills, G

2005-04-28

Illumination of air-free aqueous solutions containing sulfonated poly(ether ether ketone) and poly(vinyl alcohol) with 350 nm light results in benzophenone ketyl radicals of the polyketone. The polymer radicals form with a quantum yield 0.02 and decay with a second-order rate constant 6 orders of magnitude lower than that of typical alpha-hydroxy radicals. Evidence is presented that the polymeric benzophenone ketyl radicals reduce Ag+, Cu2+, and AuCl4- to metal particles of nanometer dimensions. Decreases in the reduction rates with increasing Ag(I), Cu(II), and Au(III) concentrations are explained using a kinetic model in which the metal ions quench the excited state of the polymeric benzophenone groups, which forms the macromolecular radicals. Quenching is fastest for Ag+, whereas Cu2+ and AuCl4- exhibit similar rate constants. Particle formation becomes more complex as the number of equivalents needed to reduce the metal ions increases; the Au(III) system is an extreme case where the radical reactions operate in parallel with secondary light-initiated and thermal reduction channels. For each metal ion, the polymer-initiated photoreactions produce crystallites possessing distinct properties, such as a very strong plasmon in the Ag case or the narrow size distribution exhibited by Au particles.

Chemical bonding and the equilibrium composition of Grignard reagents in ethereal solutions.

Science.gov (United States)

Henriques, André M; Barbosa, André G H

2011-11-10

A thorough analysis of the electronic structure and thermodynamic aspects of Grignard reagents and its associated equilibrium composition in ethereal solutions is performed. Considering methylmagnesium halides containing fluorine, chlorine, and bromine, we studied the neutral, charged, and radical species associated with their chemical equilibrium in solution. The ethereal solvents considered, tetrahydrofuran (THF) and ethyl ether (Et(2)O), were modeled using the polarizable continuum model (PCM) and also by explicit coordination to the Mg atoms in a cluster. The chemical bonding of the species that constitute the Grignard reagent is analyzed in detail with generalized valence bond (GVB) wave functions. Equilibrium constants were calculated with the DFT/M06 functional and GVB wave functions, yielding similar results. According to our calculations and existing kinetic and electrochemical evidence, the species R(•), R(-), (•)MgX, and RMgX(2)(-) must be present in low concentration in the equilibrium. We conclude that depending on the halogen, a different route must be followed to produce the relevant equilibrium species in each case. Chloride and bromide must preferably follow a "radical-based" pathway, and fluoride must follow a "carbanionic-based" pathway. These different mechanisms are contrasted against the available experimental results and are proven to be consistent with the existing thermodynamic data on the Grignard reagent equilibria.

Decoration of a Poly(methyl vinyl ether-co-maleic anhydride)-Shelled Selol Nanocapsule with Folic Acid Increases Its Activity Against Different Cancer Cell Lines In Vitro.

Science.gov (United States)

Ganassin, Rayane; Souza, Ludmilla Regina de; Py-Daniel, Karen Rapp; Longo, João Paulo Figueiró; Coelho, Janaína Moreira; Rodrigues, Mosar Correa; Jiang, Cheng-Shi; Gu, Jinsong; Morais, Paulo César de; Mosiniewicz-Szablewska, Ewa; Suchocki, Piotr; Báo, Sônia Nair; Azevedo, Ricardo Bentes; Muehlmann, Luis Alexandre

2018-01-01

Due to the low therapeutic index of different chemotherapeutic drugs used for cancer treatment, the development of new anticancer drugs remains an intense field of research. A recently developed mixture of selenitetriacylglycerides, selol, was shown to be active against different cancer cells in vitro. As this compound is highly hydrophobic, it was encapsulated, in a previous study, into poly(methyl vinyl ether-co-maleic anhydride)-shelled nanocapsules in order to improve its dispersibility in aqueous media. Following this line of research, the present report aimed at enhancing the In Vitro activity of the selol nanocapsules against cancerous cells by decorating their surface with folic acid. It is known that several cancer cells overexpress folate receptors. Stable folic acid-decorated selol nanocapsules (SNP-FA) were obtained, which showed to be spherical, with a hydro-dynamic diameter of 364 nm, and zeta potential of -24 mV. In comparison to non-decorated selol nanocapsules, SNP-FA presented higher activity against 4T1, MCF-7 and HeLa cells. Moreover, the decoration of the nanocapsules did not alter their toxicity towards fibroblasts, NIH-3T3 cells. These results show that the decoration with folic acid increased the toxicity of selol nanocapsules to cancer cells. These nanocapsules, besides enabling to disperse selol in an aqueous medium, increased the toxicity of this drug In Vitro, and may be useful to treat cancer in vivo, potentially increasing the specificity of selol towards cancer cells.

Exogenous ether lipids predominantly target mitochondria

DEFF Research Database (Denmark)

Kuerschner, Lars; Richter, Doris; Hannibal-Bach, Hans Kristian

2012-01-01

Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high......, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria...

Mass transport of direct methanol fuel cell species in sulfonated poly(ether ether ketone) membranes

International Nuclear Information System (INIS)

Silva, V.S.; Ruffmann, B.; Vetter, S.; Boaventura, M.; Mendes, A.M.; Madeira, L.M.; Nunes, S.P.

2006-01-01

Homogeneous membranes based on sulfonated poly(ether ether ketone) (sPEEK) with different sulfonation degrees (SD) were prepared and characterized. In order to perform a critical analysis of the SD effect on the polymer barrier and mass transport properties towards direct methanol fuel cell species, proton conductivity, water/methanol pervaporation and nitrogen/oxygen/carbon dioxide pressure rise method experiments are proposed. This procedure allows the evaluation of the individual permeability coefficients in hydrated sPEEK membranes with different sulfonation degrees. Nafion[reg] 112 was used as reference material. DMFC tests were also performed at 50 deg. C. It was observed that the proton conductivity and the permeability towards water, methanol, oxygen and carbon dioxide increase with the sPEEK sulfonation degree. In contrast, the SD seems to not affect the nitrogen permeability coefficient. In terms of selectivity, it was observed that the carbon dioxide/oxygen selectivity increases with the sPEEK SD. In contrast, the nitrogen/oxygen selectivity decreases. In terms of barrier properties for preventing the DMFC reactants loss, the polymer electrolyte membrane based on the sulfonated poly(ether ether ketone) with SD lower or equal to 71%, although having slightly lower proton conductivity, presented much better characteristics for fuel cell applications compared with the well known Nafion[reg] 112. In terms of the DMFC tests of the studied membranes at low temperature, the sPEEK membrane with SD = 71% showed to have similar performance, or even better, as that of Nafion[reg] 112. However, the highest DMFC overall efficiency was achieved using sPEEK membrane with SD = 52%

Preparation and characterization of proton exchange poly (ether sulfone)s membranes grafted propane sulfonic acid on pendant phenyl groups

International Nuclear Information System (INIS)

Lim, Youngdon; Seo, Dongwan; Hossain, Md. Awlad; Lee, Soonho; Lim, Jinseong; Jang, Hohyoun; Hong, Taehoon; Kim,; Kim, Whangi

2014-01-01

Poly(ether sulfone)s containing hexaphenyl (PHP) was prepared by 1,2-bis(4-hydroxyphenyl)-3,4,5,6-tetraphenylbenzene, 4,4-hydroxyphenylsulfone, and 4,4-fluorophenylsulfone, followed bromination on phenyl groups to produce brominated PHP (Br-PHP). Grafted sulfonated poly(ether sulfone)s containing hexaphenyl (GSPHP) were prepared from Br-PHP and 3-bromopropane sulfonic acid with potassium salt and copper powder. The salt form was converted to free acid using 1 M sulfuric acid solution. All these membranes were cast from dimethylacetamide (DMAc). The structural properties of the synthesized polymers were investigated by 1 H-NMR spectroscopy. The membranes were studied with regard to ion exchange capacity (IEC), water uptake, Fenton test, and proton conductivity. These grafted polymer membranes were compared with normal sulfonated poly(ether sulfone)s and Nafion

Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

Energy Technology Data Exchange (ETDEWEB)

Mai, Zhensheng; Bi, Cheng; Dai, Hua [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Huamin; Li, Xianfeng [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China)

2011-01-01

Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test. (author)

Application of simplified PC-SAFT to glycol ethers

DEFF Research Database (Denmark)

Avlund, Ane Søgaard; Kontogeorgis, Georgios; Michelsen, Michael Locht

2012-01-01

The simplified PC-SAFT (sPC-SAFT) equation of state is applied for binary glycol ether-containing mixtures, and it is investigated how the results are influenced by inclusion of intramolecular association in the association theory. Three different glycol ethers are examined: 2-methoxyethanol, 2...

Origin of mechanical modifications in poly (ether ether ketone)/carbon nanotube composite

International Nuclear Information System (INIS)

Pavlenko, Ekaterina; Puech, Pascal; Bacsa, Wolfgang; Boyer, François; Olivier, Philippe; Sapelkin, Andrei; King, Stephen; Heenan, Richard; Pons, François; Gauthier, Bénédicte; Cadaux, Pierre-Henri

2014-01-01

Variations in the hardness of a poly (ether ether ketone) beam electrically modified with multi-walled carbon nanotubes (MWCNT, 0.5%-3%) are investigated. It is shown that both rupture and hardness variations correlate with the changes in carbon nanotube concentration when using micro indentation and extended Raman imaging. Statistical analysis of the relative spectral intensities in the Raman image is used to estimate local tube concentration and polymer crystallinity. We show that the histogram of the Raman D band across the image provides information about the amount of MWCNTs and the dispersion of MWCNTs in the composite. We speculate that we have observed a local modification of the ordering between pure and modified polymer. This is partially supported by small angle neutron scattering measurements, which indicate that the agglomeration state of the MWCNTs is the same at the concentrations studied.

Origin of mechanical modifications in poly (ether ether ketone)/carbon nanotube composite

Energy Technology Data Exchange (ETDEWEB)

Pavlenko, Ekaterina; Puech, Pascal; Bacsa, Wolfgang, E-mail: wolfgang.bacsa@cemes.fr [CEMES-CNRS and University of Toulouse, 29 Jeanne Marvig, 31055 Toulouse (France); Boyer, François; Olivier, Philippe [Université de Toulouse, Institut Clément Ader, I.U.T. Université Paul Sabatier - 133C Avenue de Rangueil - B.P. 67701, 31077 Toulouse CEDEX 4 (France); Sapelkin, Andrei [School of Physics and Astronomy, Queen Mary, University of London, Mile End Road, E1 4NS London (United Kingdom); King, Stephen; Heenan, Richard [ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX Didcot (United Kingdom); Pons, François; Gauthier, Bénédicte; Cadaux, Pierre-Henri [AIRBUS FRANCE (B.E. M and P Toulouse), 316 Route de Bayonne, 31060 Toulouse (France)

2014-06-21

Variations in the hardness of a poly (ether ether ketone) beam electrically modified with multi-walled carbon nanotubes (MWCNT, 0.5%-3%) are investigated. It is shown that both rupture and hardness variations correlate with the changes in carbon nanotube concentration when using micro indentation and extended Raman imaging. Statistical analysis of the relative spectral intensities in the Raman image is used to estimate local tube concentration and polymer crystallinity. We show that the histogram of the Raman D band across the image provides information about the amount of MWCNTs and the dispersion of MWCNTs in the composite. We speculate that we have observed a local modification of the ordering between pure and modified polymer. This is partially supported by small angle neutron scattering measurements, which indicate that the agglomeration state of the MWCNTs is the same at the concentrations studied.

Influence of wood extractives in the polymerization of methyl methacrylate by gamma irradiation

International Nuclear Information System (INIS)

Burillo de V, G.; Loyola V, V.M.; Albarran S, G.; Candelas, J.

1975-01-01

Those materials that can be extracted from pine or oak by ether, ethanol, methyl methacrylate (MMA), or benzene--alcohol all act as inhibitors in the γ polymerization of MMA--wood composites. It was found that preirradiation of either the wood or of the wood--monomer combination reduces or eliminates the inhibitory effect. The most practical industrial solution to this problem is to increase the dose, thereby achieving high molecular polymer in the composite. However, the presence of a maximum in the molecular weight--dose curves means that each wood--monomer pair may have a different optimum dose

A highly sensitive and selective dimethyl ether sensor based on cataluminescence.

Science.gov (United States)

Zhang, Runkun; Cao, Xiaoan; Liu, Yonghui; Peng, Yan

2010-07-15

A sensor for detecting dimethyl ether was designed based on the cataluminescence phenomenon when dimethyl ether vapors were passing through the surface of the ceramic heater. The proposed sensor showed high sensitivity and selectivity to dimethyl ether at an optimal temperature of 279 degrees C. Quantitative analysis were performed at a wavelength of 425 nm, the flow rate of carrier air is around 300 mL/min. The linear range of the cataluminescence intensity versus concentration of dimethyl ether is 100-6.0x10(3) ppm with a detection limit of 80 ppm. The sensor response time is 2.5 s. Under the optimized conditions, none or only very low levels of interference were observed while the foreign substances such as benzene, formaldehyde, ammonia, methanol, ethanol, acetaldehyde, acetic acid, acrolein, isopropyl ether, ethyl acetate, glycol ether and 2-methoxyethanol were passing through the sensor. Since the sensor does not need to prepare and fix up the granular catalyst, the simple technology reduces cost, improves stability and extends life span. The method can be applied to facilitate detection of dimethyl ether in the air. The possible mechanism of cataluminescence from the oxidation of dimethyl ether on the surface of ceramic heater was discussed based on the reaction products. Copyright 2010 Elsevier B.V. All rights reserved.

Time of erythema onset after application of methyl nicotinate ointments as response parameter: influence of penetration kinetics and enhancing agents.

Science.gov (United States)

Remane, Y; Leopold, C S

2006-01-01

The time of erythema onset may be used as a response parameter for quantification of the cutaneous erythema response induced by methyl nicotinate. The vehicles light mineral oil (LMO; test) and medium chain triglycerides (MCT; standard) were compared with regard to the pharmacodynamic response. Moreover, the influence of penetration enhancers on the time of erythema onset was investigated under zero order penetration kinetics. The enhancers dimethyl sulfoxide, diethylene glycol monoethyl ether and three different glycerides in different concentrations were added to MCT as a standard vehicle. All preparations were applied to the forearms of volunteers under infinite dose conditions at different thermodynamic drug activity levels (0.2-3.2% of the saturation level) and different drug concentrations (0.051-0.816%), respectively. Different penetration kinetics do not influence data of erythema onset, as these data are comparable to those obtained under finite dose conditions (first order penetration kinetics). With regard to the penetration enhancers, a significantly enhanced penetration of methyl nicotinate could be observed only for diethylene glycol monoethyl ether and dimethyl sulfoxide. However, no significant difference between light mineral oil and MCT could be found with regard to penetration enhancement. The time of erythema onset is an easy and efficient parameter for quantification of the pharmacodynamic response caused by nicotinates.

Unitary information ether and its possible applications

International Nuclear Information System (INIS)

Horodecki, R.

1991-01-01

The idea of information ether as the unitary information field is developed. It rests on the assumption that the notion of information is a fundamental category in the description of reality and that it can be defined independently from the notion of probability itself. It is shown that the information ether provides a deterministic background for the nonlinear wave hypothesis and quantum cybernetics. (orig.)

The Ether Wind and the Global Positioning System.

Science.gov (United States)

Muller, Rainer

2000-01-01

Explains how students can perform a refutation of the ether theory using information from the Global Positioning System (GPS). Discusses the functioning of the GPS, qualitatively describes how position determination would be affected by an ether wind, and illustrates the pertinent ideas with a simple quantitative model. (WRM)

Contemporary 14C radiocarbon levels of oxygenated polybrominated diphenyl ethers (O-PBDEs) isolated in sponge–cyanobacteria associations

Science.gov (United States)

Guitart, Carlos; Slattery, Marc; Ankisetty, Sridevi; Radwan, Mohamed; Ross, Samir J.; Letcher, Robert J.; Reddy, Christopher M.

2016-01-01

Considerable debate surrounds the sources of oxygenated polybrominated diphenyl ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from anthropogenic industrial activities. Natural radiocarbon (14C) abundance has proven to be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas industrial chemicals, mostly produced from fossil fuels, contain no detectable 14C. However, few compounds isolated from organisms have been analyzed for their radiocarbon content. To provide a baseline, we analyzed the 14C content of four O-PBDEs. These compounds, 6-OH-BDE47, 2′-OHBDE68, 2′,6-diOH-BDE159, and a recently identified compound, 2′-MeO-6-OH-BDE120, were isolated from the tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern radiocarbon content of their chemical structures (i.e. diphenyl ethers, C12H22O) indicates that they are naturally produced. This adds to a growing baseline on, at least, the sources of these unusual compounds. PMID:21276990

Synthesis of Poly(vinyl ether) Thermoplastic Elastomers Having Functional Soft Segments

OpenAIRE

今枝, 嗣人; 漆崎, 美智遠; 阪口, 壽一; 橋本, 保; Tsuguto, IMAEDA; Michio, URUSHISAKI; Toshikazu, SAKAGUCHI; Tamotsu, HASHIMOTO

2013-01-01

The ABA-type triblock copolymers consisting of poly(2-adarnantyl vinyl ether) [poly(2-AdVE) as outer hard segments and poly(6-acetoxyhexyl vinyl ether) [poly(AcHVE)] poly(6-hydroxyhexyl vinyl ether) [poly(H HVE)], or poly(2-(2-methoxyethoxy)ethyl vinyl ether [poly(MOEOVE)] as inner soft segments were synthesized by sequential living cationic polymerization. Despite the presence of polar functional groups such as ester, hydroxy, and oxyethylene units in their soft segments, the two polymer seg...

Effects of a thirteen-week inhalation exposure to ethyl tertiary butyl ether on fischer-344 rats and CD-1 mice.

Science.gov (United States)

Medinsky, M A; Wolf, D C; Cattley, R C; Wong, B; Janszen, D B; Farris, G M; Wright, G A; Bond, J A

1999-09-01

The 1990 Clean Air Act Amendments require that oxygenates be added to automotive fuels to reduce emissions of carbon monoxide and hydrocarbons. One potential oxygenate is the aliphatic ether ethyl tertiary butyl ether (ETBE). Our objective was to provide data on the potential toxic effects of ETBE. Male and female Fisher 344 rats and CD-1 mice were exposed to 0 (control), 500, 1750, or 5000 ppm of ETBE for 6 h/day and 5 days/wk over a 13-week period. ETBE exposure had no effect on mortality and body weight with the exception of an increase in body weights of the female rats in the 5000-ppm group. No major changes in clinical pathology parameters were noted for either rats or mice exposed to ETBE for 6 (rats only) or 13 weeks. Liver weights increased with increasing ETBE-exposure concentration for both sexes of rats and mice. Increases in kidney, adrenal, and heart (females only) weights were noted in rats. Degenerative changes in testicular seminiferous tubules were observed in male rats exposed to 1750 and 5000 ppm but were not seen in mice. This testicular lesion has not been reported previously for aliphatic ethers. Increases in the incidence of regenerative foci, rates of renal cell proliferation, and alpha2u-globulin containing protein droplets were noted in the kidneys of all treated male rats. These lesions are associated with the male rat-specific syndrome of alpha2u-globulin nephropathy. Increases in the incidence of centrilobular hepatocyte hypertrophy and rates of hepatocyte cell proliferation were seen in the livers of male and female mice in the 5000-ppm group, consistent with a mitogenic response to ETBE. These two target organs for ETBE toxicity, mouse liver and male rat kidney, have also been reported for methyl tertiary butyl ether and unleaded gasoline.

The breakdown of vinyl ethers as a two-center synchronous reaction

Science.gov (United States)

Pokidova, T. S.; Shestakov, A. F.

2009-11-01

The experimental data on the molecular decomposition of vinyl ethers of various structures to alkanes and the corresponding aldehydes or ketones in the gas phase were analyzed using the method of intersecting parabolas. The enthalpies and kinetic parameters of decomposition were calculated for 17 reactions. The breakdown of ethers is a two-center concerted reaction characterized by a very high classical potential barrier to the thermally neutral reaction (180-190 kJ/mol). The kinetic parameters (activation energies and rate constants) of back reactions of the formation of vinyl ethers in the addition of aldehydes or ketones to alkanes were calculated using the method of intersecting parabolas. The factors that influenced the activation energy of the decomposition and formation of ethers were discussed. Quantum-chemical calculations of several vinyl ether decomposition reactions were performed. Ether formation reactions were compared with the formation of unsaturated alcohols as competitive reactions, which can occur in the interaction of carbonyl compounds with alkenes.

Comparison of in vitro and in vivo phototoxicity tests with S-(-)-10,11-dihydroxyfarnesic acid methyl ester produced by Beauveria bassiana KACC46831.

Science.gov (United States)

Kim, Min-A; Son, Hyeong-U; Yoon, Cheol-Sik; Nam, Sung-Hee; Choi, Young-Cheol; Lee, Sang-Han

2014-09-01

Beauveria bassiana is a fungi that is well-known for demonstrating a resistance to environmental change. To confirm whether S-(-)-10,11-dihydroxyfarnesic acid methyl ester (DHFAME) produced by Beauveria bassiana KACC46831 causes phototoxicity when used for cosmetic purposes due to its anti-tyrosinase activity, we conducted in vitro and in vivo phototoxicity tests. There were no significant changes or damage observed in the compound-treated group with regards to skin phototoxicity, while 8-methoxypsoralen, which served as a positive control, induced toxic effects. The in vitro 3T3 neutral red uptake assay, an alternative assessment, was used for further confirmation of the phototoxicity. The results showed that DHFAME did not exhibit phototoxicity at the designated concentrations, with or without UV irradiation in the 3T3 cells. These results indicated that the methyl ester produced by Beauveria bassiana KACC46831 does not induce phototoxicity in the skin. Therefore, the results of the present study indicate that DHFAME shows potential for use as a cosmetic ingredient that does not cause skin phototoxicity.

Fast liquid chromatography-tandem mass spectrometry for the analysis of bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether and their derivatives in canned food and beverages.

Science.gov (United States)

Gallart-Ayala, H; Moyano, E; Galceran, M T

2011-03-25

In this work a fast liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method using a C18 Fused Core™ column, was developed for the simultaneous analysis of bisphenol A diglycidyl ether (BADGE), bisphenol A (2,3-dihydroxypropyl) glycidyl ether (BADGE·H(2)O), bisphenol A bis(2,3-dihydroxypropyl) ether (BADGE·2H(2)O), bisphenol A (3-chloro-2-hydroxypropyl) glycidyl ether (BADGE·HCl), bisphenol A bis(3-chloro-2-hydroxypropyl) ether (BADGE·2HCl) and bisphenol A (3-chloro-2-hydroxypropyl)(2,3-dihydroxypropyl ether) (BADGE·HCl·H(2)O) and bisphenol F diglycidyl ether (BFDGE), bisphenol F bis(2,3-dihydroxypropyl) ether (BFDGE·2H(2)O), bisphenol F bis(3-chloro-2-hydroxypropyl) ether (BFDGE·2HCl). The LC method was coupled with a triple quadrupole mass spectrometer, using an ESI source in positive mode and using the [M+NH(4)](+) adduct as precursor ion for tandem mass spectrometry experiments. The method developed was applied to the determination of these compounds in canned soft drinks and canned food. OASIS HLB solid phase extraction (SPE) cartridges were used for the analysis of soft drinks, while solid canned food was extracted with ethyl acetate. Method limits of quantitation ranged from 0.13 μgL(-1) to 1.6 μgL(-1) in soft drinks and 1.0 μgkg(-1) to 4.0 μgkg(-1) in food samples. BADGE·2H(2)O was detected in all the analyzed samples, while other BADGEs such as BADGE·H(2)O, BADGE·HCl·H(2)O, BADGE·HCl and BADGE·2HCl were also detected in canned foods. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of p-amino-diphenyl ethers on hepatic microsomal cytochrome P450.

Science.gov (United States)

Jiang, Huidi; Xuan, Guida

2003-09-01

The present paper aims to investigate whether p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450. Mice were given daily intraperitoneal (ip) injections of p-amino-2',4'-dichlorodiphenyl ether (0.25 mmol/kg) or p-amino-4'-methyldiphenyl ether (0.25 mmol/kg) for 4 days and tested at 24 h and 48 h after the last dose injection. The results showed the mice pentobarbital sleeping time was shorter and the P450 content of hepatic microsome increased significantly in the group pretreated with p-amino-4'-methyldiphenyl ether when compared with the control group, while in mice pretreated with p-amino-2',4'-dichlorodiphenyl ether the hepatic microsome P450 content increased but the pentobarbital sleeping time was extended in clear contrast to the control group. The sleeping time of the phenobarbital group (80 mg/kg daily ip injection for 4 days) was shortened at 24 h after the last injection with increased P450 content of hepatic microsome, but it showed no difference at 48 h. The zoxazolamine-paralysis times of mice treated with p-amino-2',4'-dichlorodiphenyl ether were longer than those of the control mice, while the same dose of zoxazolamine did not lead to paralysis in mice pretreated with BNF. p-Amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether inhibited the activity of 7-ethoxyresorufin O-deethylase from rat hepatic microsome induced by BNF in vitro by 70.0% and 50.1% respectively. These results suggest that p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450.

Structure, bioactivity, and synthesis of methylated flavonoids.

Science.gov (United States)

Wen, Lingrong; Jiang, Yueming; Yang, Jiali; Zhao, Yupeng; Tian, Miaomiao; Yang, Bao

2017-06-01

Methylated flavonoids are an important type of natural flavonoid derivative with potentially multiple health benefits; among other things, they have improved bioavailability compared with flavonoid precursors. Flavonoids have been documented to have broad bioactivities, such as anticancer, immunomodulation, and antioxidant activities, that can be elevated, to a certain extent, by methylation. Understanding the structure, bioactivity, and bioavailability of methylated flavonoids, therefore, is an interesting topic with broad potential applications. Though methylated flavonoids are widely present in plants, their levels are usually low. Because developing efficient techniques to produce these chemicals would likely be beneficial, we provide an overview of their chemical and biological synthesis. © 2017 New York Academy of Sciences.

Poly(mono/diethylene glycol n-tetradecyl ether vinyl ethers with Various Molecular Weights as Phase Change Materials

Directory of Open Access Journals (Sweden)

Dongfang Pei

2018-02-01

Full Text Available At present, research on the relationship of comb-like polymer phase change material structures and their heat storage performance is scarce. Therefore, this relationship from both micro and macro perspectives will be studied in this paper. In order to achieve a high phase change enthalpy, ethylene glycol segments were introduced between the vinyl and the alkyl side chains. A series of poly(mono/diethylene glycol n-tetradecyl ether vinyl ethers (PC14EnVEs (n = 1, 2 with various molecular weights were polymerized by living cationic polymerization. The results of PC14E1VE and PC14E2VE showed that the minimum number of carbon atoms required for side-chain crystallization were 7.7 and 7.2, which were lower than that reported in the literature. The phase change enthalpy 89 J/g (for poly(mono ethylene glycol n-tetradecyl ether vinyl ethers and 86 J/g (for poly(hexadecyl acrylate were approximately equal. With the increase of molecular weight, the melting temperature, the melting enthalpy, and the initial thermal decomposition temperature of PC14E1VE changed from 27.0 to 28.0 °C, from 95 to 89 J/g, and from 264 to 287 °C, respectively. When the number average molar mass of PC14EnVEs exceeded 20,000, the enthalpy values remained basically unchanged. The introduction of the ethylene glycol chain was conducive to the crystallization of alkyl side chains.

Sulfonated polyphenyl ether by electropolymerization

International Nuclear Information System (INIS)

Hou Hongying; Vacandio, Florence; Di Vona, Maria Luisa; Knauth, Philippe

2012-01-01

Highlights: ► Sulfonated polyphenyl ether was for the first time electropolymerized. ► This technique allows the economical preparation of ionomeric membranes for electrochemical energy technologies. ► The mechanism of electropolymerization was discussed in detail. - Abstract: Electropolymerization of sulfonated phenol was for the first time achieved and studied by cyclic voltammetry (CV) and chronoamperometry on stainless steel substrates. The obtained sulfonated polyphenyl ether was characterized in terms of impedance spectroscopy, nuclear magnetic resonance (NMR), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and Fourier-Transform Infrared (FTIR) spectroscopy. Dense films of micrometer thickness can be obtained; the proton conductivity is about 3 mS/cm at room temperature.

Synthesis of acrylate guar-gum for delivery of bio-active molecules

Indian Academy of Sciences (India)

used in a number of industries (pharmaceutics, personal care, enhanced oil recovery) in which ... to produce guar-gum propyl and methyl ethers, esters and phosphates. ... dation, salt tolerance, faster hydration rate, enzyme resistance, dispersibility, improved dry ... has excellent ability to control rheology by economic water.

Reactive phase inversion for manufacture of asymmetric poly (ether imide sulfone) membranes

KAUST Repository

Jalal, Taghreed; Charry Prada, Iran David; Tayouo Djinsu, Russell; Giannelis, Emmanuel P.; Nunes, Suzana Pereira

2014-01-01

Poly (ether imide sulfone) membranes were manufactured by combining phase inversion and functionalization reaction between epoxy groups and amine modified polyether oligomers (Jeffamine) or TiO2 nanoparticles. Polysilsesquioxanes containing epoxy functionalities were in-situ grown in the casting solution and made available for further reaction with amines in the coagulation/annealing baths. The membranes were characterized by field emission scanning electron microscopy, porosimetry and water flux measurements. Water permeances up to 1500 l m-2 h-1 bar-1 were obtained with sharp pore size distribution and a pore diameter peak at 66 nm, confirmed by porosimetry, which allowed 99.2% rejection of γ-globulin. Water flux recovery of 77.5% was achieved after filtration with proteins. The membranes were stable in 50:50 dimethylformamide/water, 50:50 N-methyl pyrrolidone/water and 100% tetrahydrofuran. The possibility of using similar concept for homogeneous and stable attachment of nanoparticles on the membrane surface was demonstrated.

Reactive phase inversion for manufacture of asymmetric poly (ether imide sulfone) membranes

KAUST Repository

Jalal, Taghreed

2014-12-01

Poly (ether imide sulfone) membranes were manufactured by combining phase inversion and functionalization reaction between epoxy groups and amine modified polyether oligomers (Jeffamine) or TiO2 nanoparticles. Polysilsesquioxanes containing epoxy functionalities were in-situ grown in the casting solution and made available for further reaction with amines in the coagulation/annealing baths. The membranes were characterized by field emission scanning electron microscopy, porosimetry and water flux measurements. Water permeances up to 1500 l m-2 h-1 bar-1 were obtained with sharp pore size distribution and a pore diameter peak at 66 nm, confirmed by porosimetry, which allowed 99.2% rejection of γ-globulin. Water flux recovery of 77.5% was achieved after filtration with proteins. The membranes were stable in 50:50 dimethylformamide/water, 50:50 N-methyl pyrrolidone/water and 100% tetrahydrofuran. The possibility of using similar concept for homogeneous and stable attachment of nanoparticles on the membrane surface was demonstrated.

Zinc Mediated Tandem Fragmentation-Allylation of Methyl 5-Iodopentofuranosides

DEFF Research Database (Denmark)

Hyldtoft, Lene; Madsen, Robert

1999-01-01

In the presence of zinc and allyl bromide methyl 5-iodopentofuranosides undergo a tandem fragmentation alkylation to give functionalized dienes. These can undergo ring-closing olefin metathesis to produce cyclohexenes which on dihydroxylation give quercitols.......In the presence of zinc and allyl bromide methyl 5-iodopentofuranosides undergo a tandem fragmentation alkylation to give functionalized dienes. These can undergo ring-closing olefin metathesis to produce cyclohexenes which on dihydroxylation give quercitols....

Flavonoids and triterpenes from the nest of the stingless bee Trigona spinipes

International Nuclear Information System (INIS)

Freitas, Marinalva O.; Ponte, Flavio A.F.; Lima, Mary Anne S.; Silveira, Edilberto R.

2008-01-01

In the Northeast of Brazil the stingless bee Trigona spinipes Fabricius injures the tree bark of cultivated Eucalyptus citriodora specimens in order to make them exudate. The chemical investigation of the ethanol extract of an entire nest of T. spinipes allowed the isolation of the cycloartane triterpene magniferolic acid and 3β-hydroxy-24-methylenecicloartan-26-oic acid, besides the flavonoids 3'-methyl quercetin, sakuranetin, kaempferol 7-methyl ether, tricetin and aromadendrin 7-methyl ether as the main compounds. The isolation of sakuranetin, kaempferol 7-methyl ether, and aromadendrin 7-methyl ether from both Trigonas spinipes' nest and the exudate from Eucalyptus, may suggest this species as a botanical origin of the nest constituents of these stingless bee in the Northeast of Brazil. The structural characterization of the isolated compounds was accomplished by spectrometric means and comparison with the literature data. (author)

Preliminary Investigation of Poly-Ether-Ether-Ketone Based on Fused Deposition Modeling for Medical Applications

Directory of Open Access Journals (Sweden)

Feng Zhao

2018-02-01

Full Text Available Poly-ether-ether-ketone (PEEK fabricated by fused deposition modeling for medical applications was evaluated in terms of mechanical strength and in vitro cytotoxicity in this study. Orthogonal experiments were firstly designed to investigate the significant factors on tensile strength. Nozzle temperature, platform temperature, and the filament diameter were tightly controlled for improved mechanical strength performance. These sensitive parameters affected the interlayer bonding and solid condition in the samples. Fourier transform infrared (FTIR spectrometry analysis was secondly conducted to compare the functional groups in PEEK granules, filaments, and printed parts. In vitro cytotoxicity test was carried out at last, and no toxic substances were introduced during the printing process.

Catalyst activity maintenance study for the liquid phase dimethyl ether process

Energy Technology Data Exchange (ETDEWEB)

Peng, X.D.; Toseland, B.A.; Underwood, R.P. [Air Products and Chemicals, Inc., Allentown, PA (United States)

1995-12-31

The co-production of dimethyl ether (DME) and methanol from syngas is a process of considerable commercial attractiveness. DME coproduction can double the productivity of a LPMEOH process when using coal-derived syngas. This in itself may offer chemical producers and power companies increased flexibility and more profitable operation. DME is also known as a clean burning liquid fuel; Amoco and Haldor-Topsoe have recently announced the use of DME as an alternative diesel fuel. Moreover, DME can be an interesting intermediate in the production of chemicals such as olefins and vinyl acetate. The current APCl liquid phase dimethyl ether (LPDME) process utilizes a physical mixture of a commercial methanol synthesis catalyst and a dehydration catalyst (e.g., {gamma}-alumina). While this arrangement provides a synergy that results in much higher syngas conversion per pass compared to the methanol-only process, the stability of the catalyst system suffers. The present project is aimed at reducing catalyst deactivation both by understanding the cause(s) of catalyst deactivation and by developing modified catalyst systems. This paper describes the current understanding of the deactivation mechanism.

Alkaloids from the hook-bearing branch of Uncaria rhynchophylla and their neuroprotective effects against glutamate-induced HT22 cell death

OpenAIRE

Qi, Wen; Yue, Si-Jia; Sun, Jia-Hong; Simpkins, James W.; Zhang, Lin; Yuan, Dan

2014-01-01

One new alkaloid, 4-geissoschizine N-oxide methyl ether (1), was isolated from the EtOH extract of the hook-bearing branch of Uncaria rhynchophylla, together with 10 known alkaloids, 3-epi-geissoschizine methyl ether (2) isolated from U. rhynchophylla for the first time, geissoschizine methyl ether (3), 4-hirsuteine N-oxide (4), hirsuteine (5), hirsutine (6), 3α-dihydro-cadambine (7), 3β-isodihydro-cadambine (8), cadambine (9), strictosamide (10), and akuammigine (11). The structures were elu...

Improved Morphology and Efficiency of n-i-p Planar Perovskite Solar Cells by Processing with Glycol Ether Additives

KAUST Repository

Ugur, Esma

2017-07-31

Planar perovskite solar cells can be prepared without high temperature processing steps typically associated with mesoporous device architectures; however, their efficiency has been lower and producing high quality perovskite films in planar devices has been challenging. Here, we report a modified two-step interdiffusion protocol suitable to prepare pin-hole free perovskite films with greatly improved morphology. This is achieved by simple addition of small amounts of glycol ethers to the preparation protocol. We unravel the impact the glycol ethers have on the perovskite film formation using in-situ UV-Vis absorbance and GIWAXS experiments. From these experiments we conclude: addition of glycol ethers changes the lead iodide to perovskite conversion dynamics and enhances the conversion efficiency, resulting in more compact polycrystalline films, and it creates micrometer-sized perovskite crystals vertically-aligned across the photoactive layer. Consequently, the average photovoltaic performance increases from 13.5% to 15.9% and reproduciability is enhanced, specifically when 2-methoxyethanol is used as additive.

Improved Morphology and Efficiency of n-i-p Planar Perovskite Solar Cells by Processing with Glycol Ether Additives

KAUST Repository

Ugur, Esma; Sheikh, Arif D.; Munir, Rahim; Khan, Jafar Iqbal; Barrit, Dounya; Amassian, Aram; Laquai, Fré dé ric

2017-01-01

Planar perovskite solar cells can be prepared without high temperature processing steps typically associated with mesoporous device architectures; however, their efficiency has been lower and producing high quality perovskite films in planar devices has been challenging. Here, we report a modified two-step interdiffusion protocol suitable to prepare pin-hole free perovskite films with greatly improved morphology. This is achieved by simple addition of small amounts of glycol ethers to the preparation protocol. We unravel the impact the glycol ethers have on the perovskite film formation using in-situ UV-Vis absorbance and GIWAXS experiments. From these experiments we conclude: addition of glycol ethers changes the lead iodide to perovskite conversion dynamics and enhances the conversion efficiency, resulting in more compact polycrystalline films, and it creates micrometer-sized perovskite crystals vertically-aligned across the photoactive layer. Consequently, the average photovoltaic performance increases from 13.5% to 15.9% and reproduciability is enhanced, specifically when 2-methoxyethanol is used as additive.

Densely quaternized poly(arylene ether)s with distinct phase separation for highly anion-conductive membranes

Science.gov (United States)

Hu, Yuanfang; Wang, Bingxi; Li, Xiao; Chen, Dongyang; Zhang, Weiying

2018-05-01

To develop high performance anion exchange membranes (AEMs), a novel bisphenol monomer bearing eight benzylmethyl groups at the outer edge of the molecule was synthesized, which after condensation polymerization with various amounts of 4,4‧-dihydroxydiphenylsulfone and 4,4‧-difluorobenzophenone yielded novel poly(arylene ether)s with densely located benzylmethyl groups. These benzylmethyl groups were then converted to quaternary ammonium groups by radical-initiated bromination and quaternization in tandem, leading to the emergence of densely quaternized poly(arylene ether sulfone)s (QA-PAEs) with controlled ion exchange capacities (IECs) ranging from 1.61 to 2.32 mmol g-1. Both small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) studies revealed distinct phase separation in the QA-PAEs. The QA-PAE-40 with an IEC of 2.32 mmol g-1 exhibited a Br- conductivity of 9.2 mS cm-1 and a SO42- conductivity of 14.0 mS cm-1 at room temperature, much higher than those of a control membrane with a similar IEC but without obvious phase separation. Therefore, phase separation of AEMs was validated to be advantageous for the efficient conducting of anions. The experimental results also showed that the QA-PAEs were promising AEM materials, especially for non-alkaline applications.

40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

Science.gov (United States)

2010-07-01

... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs P...

Congenital malformations and maternal occupational exposure to glycol ethers

NARCIS (Netherlands)

Cordier, S; Bergeret, A; Goujard, J; Ha, MC; Ayme, S; Calzolari, E; DeWalle, HEK; KnillJones, R; Candela, S; Dale, [No Value; Dananche, B; deVigan, C; Fevotte, J; Kiel, G; Mandereau, L

Glycol ethers are found in a wide range of domestic and industrial products, many of which are used in women's work environments. Motivated by concern about their potential reproductive toxicity, we have evaluated the risk of congenital malformations related to glycol ether exposure during preg

Structure, function and carcinogenicity of metabolites of methylated and non-methylated polycyclic aromatic hydrocarbons: a comprehensive review.

Science.gov (United States)

Flesher, James W; Lehner, Andreas F

2016-01-01

The Unified Theory of PAH Carcinogenicity accommodates the activities of methylated and non-methylated polycyclic aromatic hydrocarbons (PAHs) and states that substitution of methyl groups on meso-methyl substituted PAHs with hydroxy, acetoxy, chloride, bromide or sulfuric acid ester groups imparts potent cancer producing properties. It incorporates specific predictions from past researchers on the mechanism of carcinogenesis by methyl-substituted hydrocarbons, including (1) requirement for metabolism to an ArCH2X type structure where X is a good leaving group and (2) biological substitution of a meso-methyl group at the most reactive center in non-methylated hydrocarbons. The Theory incorporates strong inferences of Fieser: (1) The mechanism of carcinogenesis involves a specific metabolic substitution of a hydrocarbon at its most reactive center and (2) Metabolic elimination of a carcinogen is a detoxifying process competitive with that of carcinogenesis and occurring by a different mechanism. According to this outlook, chemical or biochemical substitution of a methyl group at the reactive meso-position of non-methylated hydrocarbons is the first step in the mechanism of carcinogenesis for most, if not all, PAHs and the most potent metabolites of PAHs are to be found among the meso methyl-substituted hydrocarbons. Some PAHs and their known or potential metabolites and closely related compounds have been tested in rats for production of sarcomas at the site of subcutaneous injection and the results strongly support the specific predictions of the Unified Theory.

Direct transformation of silyl enol ethers into functionalized allenes.

Science.gov (United States)

Langer, P; Döring, M; Seyferth, D; Görls, H

2001-02-02

The first elimination reactions of silyl enol ethers to lithiated allenes are reported. These reactions allow a direct transformation of readily available silyl enol ethers into functionalized allenes. The action of three to four equivalents of lithium diisopropylamide (LDA) on silyl enol ethers results in the formation of lithiated allenes by initial allylic lithiation, subsequent elimination of a lithium silanolate, and finally, lithiation of the allene thus formed. Starting with amide-derived silyl imino ethers, lithiated ketenimines are obtained. A variety of reactions of the lithiated allenes with electrophiles (chlorosilanes, trimethylchlorostannane, dimethyl sulfate and ethanol) were carried out. Elimination of silanolate is observed only for substrates that contain the hindered SiMe2tBu or Si(iPr)3 moiety, but not for the SiMe3 group. The reaction of 1,1-dilithio-3,3-diphenylallene with ketones provides a convenient access to novel 1,1-di(hydroxymethyl)allenes which undergo a domino Nazarov-Friedel-Crafts reaction upon treatment with p-toluenesulfonic acid.

Real time in situ spectroscopic characterization of radiation induced cationic polymerization of glycidyl ethers

International Nuclear Information System (INIS)

Mascioni, Matteo; Sands, James M.; Palmese, Giuseppe R.

2003-01-01

Radiation curable polymeric materials suffer from relatively poor mechanical properties. Moreover, the curing behavior of such systems (i.e. the exact relationship between chemical kinetics and key processing variables) is not fully understood. In order to design improved epoxy based electron beam (EB) curable systems, and in order to develop appropriate process models, a detailed knowledge of the kinetics of epoxy cationic polymerization induced by ultraviolet (UV) or EB irradiation is required. In this work, we present our development of a technique based on real time near infrared (RTIR) spectroscopy for performing in situ kinetic analysis of radiation induced cationic polymerization of epoxy systems. To our knowledge this is the first time such data have been collected and presented for high-energy EB (10 MeV) induced polymerization. A demonstration of the technique for deterministic evaluation of degree of cure is shown using model glycidyl ether (phenyl glycidyl ether and diglycidyl ether of bisphenol A) resins and isothermal curing conditions. The impact of initiation rate on polymerizations with UV and EB for the cationic initiator is directly evident by comparative analysis. The sensitivity of the RTIR method and ability to produce quantitative data evidence of reaction mechanisms is demonstrated. The type of data presented in this work forms the basis for cure models being developed

Health assessment of gasoline and fuel oxygenate vapors: Neurotoxicity evaluation

OpenAIRE

O?Callaghan, James P.; Daughtrey, Wayne C.; Clark, Charles R.; Schreiner, Ceinwen A.; White, Russell

2014-01-01

Sprague?Dawley rats were exposed via inhalation to vapor condensates of either gasoline or gasoline combined with various fuel oxygenates to assess potential neurotoxicity of evaporative emissions. Test articles included vapor condensates prepared from ?baseline gasoline? (BGVC), or gasoline combined with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA). Target concentrati...

Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide

International Nuclear Information System (INIS)

Domanska, Urszula; Marciniak, Andrzej

2009-01-01

The activity coefficients at infinite dilution, γ 13 ∞ for 36 solutes: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide [bmPY][NTf 2 ] were determined by gas-liquid chromatography at temperatures from 298.15 K to 368.15 K. The partial molar excess enthalpies at infinite dilution values ΔH 1 E,∞ were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The selectivity for different separation problems were calculated from the γ 13 ∞ and compared to the literature values for other ionic liquids, N-methyl-2-pyrrolidinone (NMP) and sulfolane.

Flavonoids and triterpenes from the nest of the stingless bee Trigona spinipes

Energy Technology Data Exchange (ETDEWEB)

Freitas, Marinalva O.; Ponte, Flavio A.F.; Lima, Mary Anne S.; Silveira, Edilberto R. [Universidade Federal do Ceara, Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica. Curso de Pos-Graduacao em Quimica Organica]. E-mail: edil@ufc.br

2008-07-01

In the Northeast of Brazil the stingless bee Trigona spinipes Fabricius injures the tree bark of cultivated Eucalyptus citriodora specimens in order to make them exudate. The chemical investigation of the ethanol extract of an entire nest of T. spinipes allowed the isolation of the cycloartane triterpene magniferolic acid and 3{beta}-hydroxy-24-methylenecicloartan-26-oic acid, besides the flavonoids 3'-methyl quercetin, sakuranetin, kaempferol 7-methyl ether, tricetin and aromadendrin 7-methyl ether as the main compounds. The isolation of sakuranetin, kaempferol 7-methyl ether, and aromadendrin 7-methyl ether from both Trigonas spinipes' nest and the exudate from Eucalyptus, may suggest this species as a botanical origin of the nest constituents of these stingless bee in the Northeast of Brazil. The structural characterization of the isolated compounds was accomplished by spectrometric means and comparison with the literature data. (author)

Magnetic modulation of exciplex fluorescence of pyrene solutions with azacrown-ether excess in the presence of ions of alkali and alkaline earth metals

International Nuclear Information System (INIS)

Borisenko, V.N.; Petrov, N.Kh.; Gromov, S.P.; Alfimov, M.V.

1997-01-01

Photoexcitation of polar pyrene solutions with excess of phenylaza-15-crown-5 as a donor results to intermolecular electron transfer with formation of ion-radical pairs, recombination of which produces fluorescent exciplex. Charge exchange between molecules of crown ether and its cation-radicals is practically absent at that. Magnetic effect, observed for fluorescence, decreases, when adding diamagnetic lithium and calcium ions to exiplex pyrene/crown-ether system. This can be explained by formation of paramagnetic complexes. 15 refs., 5 figs

Modification of sodium and potassium channel kinetics by diethyl ether and studies on sodium channel inactivation in the crayfish giant axon membrane

Energy Technology Data Exchange (ETDEWEB)

Bean, Bruce Palmer [Univ. of Rochester, NY (United States)

1979-01-01

The effects of ether and halothane on membrane currents in the voltage clamped crayfish giant axon membrane were investigated. Concentrations of ether up to 300 mM and of halothane up to 32 mM had no effect on resting potential or leakage conductance. Ether and halothane reduced the size of sodium currents without changing the voltage dependence of the peak currents or their reversal potential. Ether and halothane also produced a reversible, dose-dependent speeding of sodium current decay at all membrane potentials. Ether reduced the time constants for inactivation, and also shifted the midpoint of the steady-state inactivation curve in the hyperpolarizing direction. Potassium currents were smaller with ether present, with no change in the voltage dependence of steady-state currents. The activation of potassium channels was faster with ether present. There was no apparent change in the capacitance of the crayfish giant axon membrane with ether concentrations of up to 100 mM. Experiments on sodium channel inactivation kinetics were performed using 4-aminopyridine to block potassium currents. Sodium currents decayed with a time course generally fit well by a single exponential. The time constant of decay was a steep function of voltage, especially in the negative resistance region of the peak current vs voltage relation.The time course of inactivation was very similar to that of the decay of the current at the same potential. The measurement of steady-state inactivation curves with different test pulses showed no shifts along the voltage asix. The voltage-dependence of the integral of sodium conductance was measured to test models of sodium channel inactivation in which channels must open before inactivating; the results appear inconsistent with some of the simplest cases of such models.

Cost estimation of hydrogen and DME produced by nuclear heat utilization system II

International Nuclear Information System (INIS)

Shiina, Yasuaki; Nishihara, Tetsuo

2004-09-01

Utilization and production of hydrogen has been studied in order to spread utilization of the hydrogen energy in 2020 or 2030. It will take, however, many years for the hydrogen energy to be used very easily like gasoline, diesel oil and city gas in the world. During the periods, low CO 2 release liquid fuels would be used together with hydrogen. Recently, di-methyl-ether (DME). has been noticed as one of the substitute liquid fuels of petroleum. Such liquid fuels can be produced from the mixed gas such as hydrogen and carbon oxide which are produced from natural gas by steam reforming. Therefore, the system would become one of the candidates of future system of nuclear heat utilization. Following the study in 2002, we performed economic evaluation of the hydrogen and DME production by nuclear heat utilization plant where heat generated by HTGR is completely consumed for the production. The results show that hydrogen price produced by nuclear was about 17% cheaper than the commercial price by increase in recovery rate of high purity hydrogen with increased in PSA process. Price of DME in indirect method produced by nuclear heat was also about 17% cheaper than the commercial price by producing high purity hydrogen in the DME producing process. As for the DME, since price of DME produced near oil land in petroleum exporting countries is cheaper than production in Japan, production of DME by nuclear heat in Japan has disadvantage economically in this time. Trial study to estimate DME price produced by direct method was performed. From the present estimation, utilization of nuclear heat for the production of hydrogen would be more effective with coupled consideration of reduction effect of CO 2 release. (author)

The ectopic expression of a pectin methyl esterase inhibitor increases pectin methyl esterification and limits fungal diseases in wheat.

Science.gov (United States)

Volpi, Chiara; Janni, Michela; Lionetti, Vincenzo; Bellincampi, Daniela; Favaron, Francesco; D'Ovidio, Renato

2011-09-01

Cell wall pectin methyl esterification can influence plant resistance because highly methyl-esterified pectin can be less susceptible to the hydrolysis by pectic enzymes such as fungal endopolygalacturonases (PG). Pectin is secreted into the cell wall in a highly methyl-esterified form and, here, is de-methyl esterified by pectin methyl esterase (PME). The activity of PME is controlled by specific protein inhibitors called PMEI; consequently, an increased inhibition of PME by PMEI might modify the pectin methyl esterification. In order to test the possibility of improving wheat resistance by modifying the methyl esterification of pectin cell wall, we have produced durum wheat transgenic lines expressing the PMEI from Actinidia chinensis (AcPMEI). The expression of AcPMEI endows wheat with a reduced endogenous PME activity, and transgenic lines expressing a high level of the inhibitor showed a significant increase in the degree of methyl esterification. These lines showed a significant reduction of disease symptoms caused by the fungal pathogens Bipolaris sorokiniana or Fusarium graminearum. This increased resistance was related to the impaired ability of these fungal pathogens to grow on methyl-esterified pectin and to a reduced activity of the fungal PG to hydrolyze methyl-esterified pectin. In addition to their importance for wheat improvement, these results highlight the primary role of pectin despite its low content in the wheat cell wall.

An improved synthesis process of calixcrown ethers and synthesis of novel calixcrown ether

International Nuclear Information System (INIS)

Wang Hairong; Zhang Ping; Wang Chunmiao; Wang Jianchen; Chen Jing

2007-01-01

The synthesis method of calixcrown ethers was simplified and improved, and 10 L- scale synthesis was carried out. In the synthesis of the intermediates of the first three steps, the synthesis of 5, 11, 17, 23-tetra-tert-butyl-25, 26, 27, 28-tetrahydroxyl-calix[4] and its dehydroxylation were considered together, the purification procedures of the former, including re-crystallization in toluene and decolorization with activated carbon, were cancelled, and thus these steps were simplified. In the synthesis of oligoethylene glycol ditosylate, the purification method was also improved and the time-consuming column chromatography was left out. In the final step, impurities were removed by repeating stirring-settlement steps, by following recrystallization, the pure product was obtained. With these measures, the whole process could be implemented easily. The industrial scale production of calixcrown ethers could be fulfilled with the improved process. In addition, a new extracant, 25, 27-bis (n-propyloxy)calix[4]-26, 28-crown-6, is prepared and identified. (authors)

Synchrotron Photoionization Investigation of the Oxidation of Ethyl tert-Butyl Ether.

Science.gov (United States)

Winfough, Matthew; Yao, Rong; Ng, Martin; Catani, Katherine; Meloni, Giovanni

2017-02-23

The oxidation of ethyl tert-butyl ether (ETBE), a widely used fuel oxygenated additive, is investigated using Cl atoms as initiators in the presence of oxygen. The reaction is carried out at 293, 550, and 700 K. Reaction products are probed by a multiplexed chemical kinetics photoionization mass spectrometer coupled with the synchrotron radiation produced at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory. Products are identified on the basis of mass-to-charge ratio, ionization energies, and shape of photoionization spectra. Reaction pathways are proposed together with detected primary products.

Investigation of ammonium trinitratouranylate complexing with diethyl ether

International Nuclear Information System (INIS)

Khod'ko, N.N.; Kolevich, T.A.; Umrejko, D.S.

1989-01-01

Interaction of ammonium trinitratouranylate (ATNU) with diethyl ether is investigated. It is shown, that adduct of UO 2 (NO 3 ) 2 · 2(C 2 H 5 ) 2 O coposition is formed in the indicated solvent due to incongruent solubility of ANTU. Analogous compound is obtained at ether effect on uranyl anhydrous nitrate. The matter is determined and investigated by means of chemical, thermal analyses and oscillating spectroscopy

Enzymes that cleave non-glycosidic ether bonds between lignins or derivatives thereof and saccharides

Science.gov (United States)

Kravit, Nancy G.; Schmidt, Katherine A.

2017-10-24

The patent application relates to isolated polypeptides that specifically cleave non-glycosidic ether bonds between lignins or derivatives thereof and saccharides, and to cDNAs encoding the polypeptides. The patent application also relates to nucleic acid constructs, expression vectors and host cells comprising the cDNAs, as well as methods of producing and using the isolated polypeptides for treating pulp and biomass to increase soluble saccharide yield and enrich lignin fractions.

UV irradiation of polycyclic aromatic hydrocarbons in ices: production of alcohols, quinones, and ethers

Science.gov (United States)

Bernstein, M. P.; Sandford, S. A.; Allamandola, L. J.; Gillette, J. S.; Clemett, S. J.; Zare, R. N.

1999-01-01

Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultraviolet (UV) radiation under astrophysical conditions, and the products were analyzed by infrared spectroscopy and mass spectrometry. Peripheral carbon atoms were oxidized, producing aromatic alcohols, ketones, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account for the interstellar 3.4-micrometer emission feature. These classes of compounds are all present in carbonaceous meteorites. Hydrogen and deuterium atoms exchange readily between the PAHs and the ice, which may explain the deuterium enrichments found in certain meteoritic molecules. This work has important implications for extraterrestrial organics in biogenesis.

Spontaneous Generation of Chirality in Simple Diaryl Ethers.

Science.gov (United States)

Lennartson, Anders; Hedström, Anna; Håkansson, Mikael

2015-07-01

We studied the spontaneous formation of chiral crystals of four diaryl ethers, 3-phenoxybenzaldehyde, 1; 1,3-dimethyl-2-phenoxybenzene, 2; di(4-aminophenyl) ether, 3; and di(p-tolyl) ether, 4. Compounds 1, 3, and 4 form conformationally chiral molecules in the solid state, while the chirality of 2 arises from the formation of supramolecular helices. Compound 1 is a liquid at ambient temperature, but 2-4 are crystalline, and solid-state CD-spectroscopy showed that they could be obtained as optically active bulk samples. It should be noted that the optical activity arise upon crystallization, and no optically active precursors were used. Indeed, even commercial samples of 3 and 4 were found to be optically active, giving evidence for the ease at which total spontaneous resolution may occur in certain systems. © 2015 Wiley Periodicals, Inc.

STABILITY OF EMULSIFIER-FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE/ BUTYL ACRYLATE/SODIUM MONO(ETHYL POLYOXYETHYLENE) MALEATE

Institute of Scientific and Technical Information of China (English)

Mao-gen Zhang; Zhi-xue Weng; Zhi-ming Huang; Zu-ren Pan

1999-01-01

A series of new water-soluble bifunctional comonomers having both carboxyl and alkyl polyoxyethylene groups, such as sodium mono(ethyl polyoxyethylene) maleate (ZE series) with various molecular weights of polyoxyethylene ethyl ether, were synthesized and characterized. The effects of the structural factor, the amount and feeding mode of the comonomers, the initiator concentration and polymerization temperature on the stability of emulsifier-free emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate (BA) in the presence of a small amount of ZE with potassium persulfate as initiator were investigated. Stable, almost monodispersed MMA/BA/ZE emulsifier-free latex particles were prepared.

Green mechanochemical oxidative decomposition of powdery decabromodiphenyl ether with persulfate

International Nuclear Information System (INIS)

Huang, Aizhen; Zhang, Zhimin; Wang, Nan; Zhu, Lihua; Zou, Jing

2016-01-01

Highlights: • MC process greatly enhanced the decomposition of PS into reactive sulfate radicals. • The mechanochemical (MC) activation of persulfate was applied to degrade BDE209. • This method could achieve a rapid and complete debromination and mineralization of BDE209. • No toxic low brominated polybrominated diphenyl ethers were produced and accumulated. • Sulfate radicals were the main oxidizing species for the decomposition of BDE209. - Abstract: A method was developed for efficiently degrading powdery decabromodiphenyl ether (BDE209) by using mechanochemical (MC) activation of persulfate (PS). Characteristic Raman spectra of BDE209 corresponding to C−Br and C−O bonds were decreased in intensity and finally disappeared as the MC reaction proceeded. The BDE209 removal was influenced by the molar ratio of PS to BDE209, the mass ratio of milling ball to reaction mixtures, the ball size, and the ball rotation speed. Under optimal conditions, the new method could achieve a complete degradation, debromination and mineralization of BDE209 within 3 h of milling. However, the degradation removal (or debromination efficiency) was decreased to only 51.7% (15.6%) and 67.8% (31.5%) for the use of CaO and peroxymonosulfate, respectively. The analyses of products demonstrated that once the degradation was initiated, BDE209 molecules were deeply debrominated and fully mineralized in the MC-PS system. The strong oxidizing ability of this system was due to the reactive sulfate radicals generated from the MC-enhanced activation of PS, which was confirmed with electron spin resonance spectroscopy. Because no toxic low brominated polybrominated diphenyl ethers were accumulated as byproducts, the proposed MC oxidative degradation method will have promising applications in the treatment of solid BDE209 at high concentrations.

Poly (ether ether ketone) derivatives: Synthetic route and characterization of nitrated and sulfonated polymers

International Nuclear Information System (INIS)

Conceicao, T.F.; Bertolino, J.R.; Barra, G.M.O.; Pires, A.T.N.

2009-01-01

Nitrated and sulfonated poly (ether ether ketone) [SNPEEK] samples were prepared through sulfonation of nitrated PEEK (NPEEK) at different temperatures resulting in polymers with distinct sulfonation degrees (SD). The sulfonation occurred preferentially in the hydroquinone segment even after 81% of this moiety had been nitrated. Sulfonation in the benzophenone moiety was achieved only in 16% of this segment at the reaction temperature of 80 deg. C. The substitution degree was obtained through the TG curves, and values were in agreement with 1 H NMR data when SD is much higher as ND (nitration degree). The highest SD obtained was 72%. Membranes of the sulfonated and nitrated PEEK (SNPEEK) were prepared by casting and showed good ductility depending on the substitution degree, with proton conductivity in the order of 10 -2 S cm -1 , an important characteristic in some applications, such as in fuel cells

Poly (ether ether ketone) derivatives: Synthetic route and characterization of nitrated and sulfonated polymers

Energy Technology Data Exchange (ETDEWEB)

Conceicao, T.F.; Bertolino, J.R. [Grupo de Estudo em Materiais Polimericos-Departamento de Quimica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil); Barra, G.M.O. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil); Pires, A.T.N. [Grupo de Estudo em Materiais Polimericos-Departamento de Quimica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil)], E-mail: alfredotiburcio@pq.cnpq.br

2009-03-01

Nitrated and sulfonated poly (ether ether ketone) [SNPEEK] samples were prepared through sulfonation of nitrated PEEK (NPEEK) at different temperatures resulting in polymers with distinct sulfonation degrees (SD). The sulfonation occurred preferentially in the hydroquinone segment even after 81% of this moiety had been nitrated. Sulfonation in the benzophenone moiety was achieved only in 16% of this segment at the reaction temperature of 80 deg. C. The substitution degree was obtained through the TG curves, and values were in agreement with {sup 1}H NMR data when SD is much higher as ND (nitration degree). The highest SD obtained was 72%. Membranes of the sulfonated and nitrated PEEK (SNPEEK) were prepared by casting and showed good ductility depending on the substitution degree, with proton conductivity in the order of 10{sup -2} S cm{sup -1}, an important characteristic in some applications, such as in fuel cells.

Interpolymer complexses of vinyl ether copolymer with polyacrylic and polymethacrylic acids

Directory of Open Access Journals (Sweden)

E. Shaikhutdinov

2012-03-01

Full Text Available The interactions between macromolecules of copolymers based on vinyl ethers (vinyl ether of monoethanolamine and vinyl buthyl ether and 2-acryloilamido-2-methylpropanesulphonic acid with polyacrylic and polymethacrylic acid and, as well as study the effect of interpolymer interactions in the adsorption of polymers at the aqueous solution-air interface were investigated. The observed synergistic increase in surface activity of macromolecules into polyelectrolyte mixtures explained by the formation of interpolymer complexes polyacid - copolymer.

Tactical Fuel and Energy Strategy for The Future Modular Force

Science.gov (United States)

2009-05-18

Environmental Protection Agency ESSP Energy Strategic Security Plan EV Electric Vehicle FAME Fatty Acid Methyl Ester Appendix...1992. Methanol can be used to make methyl tertiary-butyl ether (MTBE), oxygenate that is blended with gasoline to enhance octane and create cleaner...Military Occupation Specialty MTBE Methyl Tertiary Butyl Ether MW Megawatt NASA National Aeronautics and Space Administration NATO North

Absorption of decabromodiphenyl ether and other organohalogen chemicals by grey seals (Halichoerus grypus)

International Nuclear Information System (INIS)

Thomas, Gareth O.; Moss, Simon E.W.; Asplund, Lillemor; Hall, Ailsa J.

2005-01-01

An input-output balance study was performed for polybrominated diphenyl ethers, polychlorinated biphenyls and some organochlorine pesticides on three captive, juvenile grey seals (Halichoerus grypus). The animals were fed a diet of herring for six months, during the last three months of which this study was performed. A supplement of decabromodiphenyl ether was included in the diet during the second month of the study. Consistently high absorption (>89%) was observed for all of the chemicals studied, whereas work on other animals has generally shown high (>80%) net absorption at log K OW OW , and very low absorption of decabromodiphenyl ether. The half-life of decabromodiphenyl ether in blood was estimated to be between 8.5 and 13 days. Measurable concentrations of decabromodiphenyl ether were detected in seal blubber at the end of the study, indicating that this chemical can be stored in adipose and may bioaccumulate. Current understanding of the mechanism of absorption of organohalogen chemicals and the potential for accumulation of decabromodiphenyl ether will need reassessing in the light of these results. - Decabromodiphenyl ether is absorbed effectively from the diet by grey seals, and can be stored in the blubber even after exposure ceases

Formation of O2-methylthymine in poly(dA-dT) on methylation with N-methyl-N-nitrosourea and dimethyl sulphate. Evidence that O2-methylthymine does not miscode during DNA synthesis.

Science.gov (United States)

Saffhill, R; Abbott, P J

1978-01-01

The alternating co-polymer has been methylated with either N methyl-N-nitrosourea (MNU) or dimethyl sulphate (DMS) and the levels of the various methylated thymidines (O2-methylthymidine, 3-methylthymidine and O4-methylthymidine) measured. MNU produced all three compounds whereas DMS only produced 3-methylthymidine and O2-methylthymidine at detectable levels. These results have been combined with our earlier results concerning the misincorporation of dGMP with E. coli DNA polymerase using MNU-methylated poly(dA-dT). These results indicate that O2-methylthymidine does not miscode during DNA synthesis. PMID:353735

Nikola Tesla, the Ether and his Telautomaton

Science.gov (United States)

Milar, Kendall

2014-03-01

In the nineteenth century physicists' understanding of the ether changed dramatically. New developments in thermodynamics, energy physics, and electricity and magnetism dictated new properties of the ether. These have traditionally been examined from the perspective of the scientists re-conceptualizing the ether. However Nikola Tesla, a prolific inventor and writer, presents a different picture of nineteenth century physics. Alongside the displays that showcased his inventions he presented alternative interpretations of physical, physiological and even psychical research. This is particularly evident in his telautomaton, a radio remote controlled boat. This invention and Tesla's descriptions of it showcase some of his novel interpretations of physical theories. He offered a perspective on nineteenth century physics that focused on practical application instead of experiment. Sometimes the understanding of physical theories that Tesla reached was counterproductive to his own inventive work; other times he offered new insights. Tesla's utilitarian interpretation of physical theories suggests a more scientifically curious and invested inventor than previously described and a connection between the scientific and inventive communities.

Extraction of hafnium by 1-phenyl-3-methyl-4-benzoyl-5-pyralozone from aqueous-alcoholic solutions

International Nuclear Information System (INIS)

Hala, J.; Prihoda, J.

1975-01-01

Extraction of hafnium by 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HL) in benzene, toluene, chloroform and tetrachloromethane from aqueous-alcoholic solutions of the formal acidity of 2M-HClO 4 was studied. Methyl, ethyl, n- and isopropyl, tert-butyl and allyl alcohol as well as ethylene glycol monomethyl ether and propylene glycol were used as organic components of the mixed aqueous-organic phase. Their presence in some cases resulted in a synergic increase in the distribution ratio of hafnium. The increase is interpreted using the results of a slope analysis and measurements of the alcohol distribution and the relative permittivity of the organic phase. It is suggested that HfL 4 molecules were solvated by alcohol molecules in the organic phase. At high alcohol concentration synergism changed into antagonism. This was caused by changes in the distribution of HL and its interaction with the alcohol in the organic phase. (author)

Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide

Energy Technology Data Exchange (ETDEWEB)

Domanska, Urszula [Physical Chemistry Department, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)], E-mail: ula@ch.pw.edu.pl; Marciniak, Andrzej [Physical Chemistry Department, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

2009-12-15

The activity coefficients at infinite dilution, {gamma}{sub 13}{sup {infinity}} for 36 solutes: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide [bmPY][NTf{sub 2}] were determined by gas-liquid chromatography at temperatures from 298.15 K to 368.15 K. The partial molar excess enthalpies at infinite dilution values {delta}H{sub 1}{sup E,{infinity}} were calculated from the experimental {gamma}{sub 13}{sup {infinity}} values obtained over the temperature range. The selectivity for different separation problems were calculated from the {gamma}{sub 13}{sup {infinity}} and compared to the literature values for other ionic liquids, N-methyl-2-pyrrolidinone (NMP) and sulfolane.

Enzymatic network for production of ether amines from alcohols

DEFF Research Database (Denmark)

Palacio, Cyntia M.; Crismaru, Ciprian G.; Bartsch, Sebastian

2016-01-01

We constructed an enzymatic network composed of three different enzymes for the synthesis of valuable ether amines. The enzymatic reactions are interconnected to catalyze the oxidation and subsequent transamination of the substrate and to provide cofactor recycling. This allows production...... of the desired ether amines from the corresponding ether alcohols with inorganic ammonium as the only additional substrate. To examine conversion, individual and overall reaction equilibria were established. Using these data, it was found that the experimentally observed conversions of up to 60% observed...... for reactions containing 10mM alcohol and up to 280mM ammonia corresponded well to predicted conversions. The results indicate that efficient amination can be driven by high concentrations of ammonia and may require improving enzyme robustness for scale-up....

Basic randomness of nature and ether-drift experiments

International Nuclear Information System (INIS)

Consoli, M.; Pluchino, A.; Rapisarda, A.

2011-01-01

Highlights: ► We re-consider the idea of a basic randomness of nature. ► We adopt Stochastic Electro Dynamics as a heuristic model. ► We represent the vacuum as a form of turbulent ether. ► This picture can be tested with forthcoming ether-drift experiments. - Abstract: We re-consider the idea that quantum fluctuations might reflect the existence of an ‘objective randomness’, i.e. a basic property of the vacuum state which is independent of any experimental accuracy of the observations or limited knowledge of initial conditions. Besides being responsible for the observed quantum behavior, this might introduce a weak, residual form of ‘noise’ which is intrinsic to natural phenomena and could be important for the emergence of complexity at higher physical levels. By adopting Stochastic Electro Dynamics as a heuristic model, we are driven to a picture of the vacuum as a form of highly turbulent ether, which is deep-rooted into the basic foundational aspects of both quantum physics and relativity, and to search for experimental tests of this scenario. An analysis of the most precise ether-drift experiments, operating both at room temperature and in the cryogenic regime, shows that, at present, there is some ambiguity in the interpretation of the data. In fact the average amplitude of the signal has precisely the magnitude expected, in a ‘Lorentzian’ form of relativity, from an underlying stochastic ether and, as such, might not be a spurious instrumental effect. This puzzle, however, should be solved in a next future with the use of new cryogenically cooled optical resonators whose stability should improve by about two orders of magnitude. In these new experimental conditions, the persistence of the present amplitude would represent a clean evidence for the type of random vacuum we are envisaging.

Biofuels for transportation. From R and D to market

Energy Technology Data Exchange (ETDEWEB)

Pilo, C [comp.

1996-11-01

The aim of the Workshop was to bring together stakeholders in industry, government and science to identify technical, economic and institutional opportunities and/or barriers to the market penetration of biofuels and to tackle these issues jointly in an international environment. The Workshop was to cover the role of biofuels in replacing fossil fuels and achieving sustainable transportation. It was to be more oriented towards policy issues than towards analyses of scientific and technical details. The Workshop was focused on the conditions in Northern Europe and North America. Three main themes were chosen: THEME 1. Biomass Feedstocks. How do we produce them cost-effectively and for what purpose? THEME 2. Biofuels for Transportation. What will make them technically and economically competitive? THEME 3. Market Penetration of Biofuels. How do we remove barriers? The following biofuels were considered during the Workshop: Alcohols, such as ethanol and methanol. Ethers, such as MTBE (methyl-tertio-butyl-ether) and ETBE (ethyl-tertio-butyl-ether). Vegetable oils and esters, such as VME (vegetable-oil-methylester), RME (rape-oil-methyl-ester) and REE (rape-oil-ethyl-ester)

Gold-catalyzed alkylation of silyl enol ethers with ortho-alkynylbenzoic acid esters

Directory of Open Access Journals (Sweden)

Yoshinori Yamamoto

2011-05-01

Full Text Available Unprecedented alkylation of silyl enol ethers has been developed by the use of ortho-alkynylbenzoic acid alkyl esters as alkylating agents in the presence of a gold catalyst. The reaction probably proceeds through the gold-induced in situ construction of leaving groups and subsequent nucleophilic attack on the silyl enol ethers. The generated leaving compound abstracts a proton to regenerate the silyl enol ether structure.

New Poly(amide-imide)/Nanocomposites Reinforced Silicate Nanoparticles Based on N-pyromellitimido-L-phenyl Alanine Containing Ether Moieties

Science.gov (United States)

Faghihi, Khalil; Shabanian, Meisam; Dadfar, Ehsan

2012-02-01

A series of Poly(amide-imide)/montmorillonite nanocomposites containing N-pyromellitimido-L-phenyl alanine moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) 5 as a source of polymer matrix was synthesized by the direct polycondensation reaction of N-pyromellitimido-L-phenyl alanine 3 with 4,4'-diamino diphenyl ether 4 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). The resulting nanocomposite films were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The results showed that organo-modified clay was dispersed homogeneously in PAI matrix. TGA indicated an enhancement of thermal stability of new nanocomposites compared with the pure polymer.

Structuring of poly ether ether ketone by ArF excimer laser radiation in different atmospheres

International Nuclear Information System (INIS)

Feng, Y.; Gottmann, J.; Kreutz, E.W.

2003-01-01

Structuring of poly ether ether ketone (PEEK) by 193 nm ArF excimer laser radiation has been investigated. Experiments were carried out in different atmospheres (air, vacuum, Ar, O 2 ) in order to study its influence on the quality of the structures and the formation of the debris. Repetition rate makes little effect on the ablation rate and roughness of the structure in presence of any kind of atmosphere, indicating for the structuring of PEEK by ArF laser radiation a large window of processing. The roughness at the bottom of the structures and the morphology of the side walls are strongly affected by the properties of the atmosphere. The smallest roughness is achieved at 0.6 J/cm 2 for all kinds of processing gases. Debris around the structures can be diminished by structuring in vacuum. Plasma expansion speed has been measured by using high speed photography

The influence of water mixtures on the dermal absorption of glycol ethers

International Nuclear Information System (INIS)

Traynor, Matthew J.; Wilkinson, Simon C.; Williams, Faith M.

2007-01-01

Glycol ethers are solvents widely used alone and as mixtures in industrial and household products. Some glycol ethers have been shown to have a range of toxic effects in humans following absorption and metabolism to their aldehyde and acid metabolites. This study assessed the influence of water mixtures on the dermal absorption of butoxyethanol and ethoxyethanol in vitro through human skin. Butoxyethanol penetrated human skin up to sixfold more rapidly from aqueous solution (50%, 450 mg/ml) than from the neat solvent. Similarly penetration of ethoxyethanol was increased threefold in the presence of water (50%, 697 mg/ml). There was a corresponding increase in apparent permeability coefficient as the glycol ether concentration in water decreased. The maximum penetration rate of water also increased in the presence of both glycol ethers. Absorption through a synthetic membrane obeyed Fick's Law and absorption through rat skin showed a similar profile to human skin but with a lesser effect. The mechanisms for this phenomenon involves disruption of the stratum corneum lipid bilayer by desiccation by neat glycol ether micelles, hydration with water mixtures and the physicochemical properties of the glycol ether-water mixtures. Full elucidation of the profile of absorption of glycol ethers from mixtures is required for risk assessment of dermal exposure. This work supports the view that risk assessments for dermal contact scenarios should ideally be based on absorption data obtained for the relevant formulation or mixture and exposure scenario and that absorption derived from permeability coefficients may be inappropriate for water-miscible solvents

A mild and efficient procedure for the synthesis of ethers from various alkyl halides

Directory of Open Access Journals (Sweden)

Mosstafa Kazemi

2013-10-01

Full Text Available A simple, mild and practical procedure has been developed for the synthesis of symmetrical and unsymmetrical ethers by using DMSO, TBAI in the presence of K2CO3. We extended the utility of Potassium carbonate as an efficient base for the preparation of ethers. A wide range of alkyl aryl and dialkyl ethers are synthezied from treatment of aliphatic alcohols and phenols with various alkyl halides in the prescence of efficient base Potassium carbonate. Secondary alkyl halides were easily converted to corresponding ethers in releatively good yields . This is a mild, simple and practical procedure for the preparation of ethers in high yields and suitable times under mild condition.

Induced production of halogenated diphenyl ethers from the marine-derived fungus Penicillium chrysogenum.

Science.gov (United States)

Yang, Guohua; Yun, Keumja; Nenkep, Viviane N; Choi, Hong Dae; Kang, Jung Sook; Son, Byeng Wha

2010-11-01

Manipulation of the fermentation of the marine-derived fungus Penicillium chrysogenum by addition of CaBr(2) resulted in induced production of bromodiphenyl ether analogs. Two new free-radical-scavenging polybrominated diphenyl ethers, 1 and 2, and three known diphenyl ethers, 3,3'-dihydroxy-5,5'-dimethyldiphenyl ether (3), and an inseparable mixture of violacerol-I (4) and violacerol-II (5) were isolated. The structures of the two new polybromodiphenyl ethers 1 and 2 were assigned by combined spectroscopic-data analysis, including deuterium-induced isotope effect. Compounds 1-3, and a mixture of 4 and 5 exhibited radical-scavenging activities against 1,1-diphenyl-2-picrylhydrazyl with IC(50) values of 18, 15, 42, and 6 μM, respectively. With the exception of 3, the compounds were, therefore, more active than the positive control, ascorbic acid (IC(50) 20 μM).

Methylated liquor treatment process in caffeine production

Science.gov (United States)

Zhou, Junbo; Yang, Mingyang; Huang, Wenjia; Cui, Shenglu; Gao, Liping

2018-02-01

The caffeine production process produces a large amount of sodium methyl sulphate in the methylated mother liquor. In order to recycle this part of ingredient, we use the mother liquid of Shijiazhuang Xin Nuowei Pharmaceutical Co., Ltd. as the object of study, the use of “nanofiltration (NF) - Dish Type Reverse Osmosis (DTRO) “combination of membrane technology for desalination and concentration. The experimental results show that the concentration of sodium sulfate in the nanofiltration solution is 0.37 g • L -1, the rejection rate is 98%, and the concentration of sodium methyl sulfate in DTRO concentrated solution is 453.80 g • L -1, which meets the requirements of the enterprise.

Evaluation of Methyl-Binding Domain Based Enrichment Approaches Revisited.

Directory of Open Access Journals (Sweden)

Karolina A Aberg

Full Text Available Methyl-binding domain (MBD enrichment followed by deep sequencing (MBD-seq, is a robust and cost efficient approach for methylome-wide association studies (MWAS. MBD-seq has been demonstrated to be capable of identifying differentially methylated regions, detecting previously reported robust associations and producing findings that replicate with other technologies such as targeted pyrosequencing of bisulfite converted DNA. There are several kits commercially available that can be used for MBD enrichment. Our previous work has involved MethylMiner (Life Technologies, Foster City, CA, USA that we chose after careful investigation of its properties. However, in a recent evaluation of five commercially available MBD-enrichment kits the performance of the MethylMiner was deemed poor. Given our positive experience with MethylMiner, we were surprised by this report. In an attempt to reproduce these findings we here have performed a direct comparison of MethylMiner with MethylCap (Diagenode Inc, Denville, NJ, USA, the best performing kit in that study. We find that both MethylMiner and MethylCap are two well performing MBD-enrichment kits. However, MethylMiner shows somewhat better enrichment efficiency and lower levels of background "noise". In addition, for the purpose of MWAS where we want to investigate the majority of CpGs, we find MethylMiner to be superior as it allows tailoring the enrichment to the regions where most CpGs are located. Using targeted bisulfite sequencing we confirmed that sites where methylation was detected by either MethylMiner or by MethylCap indeed were methylated.

Catalytic hydrolysis of Metil Teret Botil Eter in under ground contaminated water

International Nuclear Information System (INIS)

Nikpey, A.; Mortazavi, B.; Asilian, H.; Khavanin, A.; Rezaee, A.; Soleimanian, A.; Kazemian, H.

2005-01-01

The behavior of ZSM-5 and Mordenite catalyst in the hydrolysis at room temperature of methyl tert-butyl ether was studied with reference to the possibility of its conversion to more biodegradable products in underground water contaminated by methyl tert-butyl ether. Hydrolysis products were determined using a gas chromatograph equipped with a flame ionization detector. The results indicate that acid ZSM-5 catalyst are effective in both adsorption and hydrolysis of methyl tert-butyl ether and may be applied for both in situ underground water remediation and as protection barrier for wells or leaking tanks. However, acid mordenite catalyst completely inactive

N-acetylcolchinol O-methyl ether and thiocolchicine, potent analogs of colchicine modified in the C ring. Evaluation of the mechanistic basis for their enhanced biological properties

International Nuclear Information System (INIS)

Kang, G.J.; Getahun, Z.; Muzaffar, A.; Brossi, A.; Hamel, E.

1990-01-01

Two colchicine analogs with modifications only in the C ring are better inhibitors than colchicine of cell growth and tubulin polymerization. Radiolabeled thiocolchicine (with a thiomethyl instead of a methoxy group at position C-10) and N-acetylcolchinol O-methyl ether (NCME) (with a methoxy-substituted benzenoid instead of the methoxy-substituted tropone C ring) were prepared for comparison with colchicine. Scatchard analysis indicated a single binding site with KD values of 1.0-2.3 microM. Thiocolchicine was bound 2-4 times as rapidly as colchicine, but the activation energies of the reactions were nearly identical (18 kcal/mol for colchicine, 20 kcal/mol for thiocolchicine). NCME bound to tubulin in a biphasic reaction. The faster phase was 60 times as fast as colchicine binding at 37 degrees C, and a substantial reaction occurred at 0 degrees C. The rate of the faster phase of NCME binding changed relatively little as a function of temperature, so the activation energy was only 7.0 kcal/mol. Dissociation reactions were also evaluated, and at 37 degrees C the half-lives of the tubulin-drug complexes were 11 min for NCME, 24 h for thiocolchicine, and 27 h for colchicine. Relative dissociation rates as a function of temperature varied little among the drug complexes. Activation energies for the dissociation reactions were 30 kcal/mol for thiocolchicine, 27 kcal/mol for NCME, and 24 kcal/mol for colchicine. Comparison of the activation energies of association and dissociation yielded free energies for the binding reactions of -20 kcal/mol for NCME, -10 kcal/mol for thiocolchicine, and -6 kcal/mol for colchicine. The greater effectiveness of NCME and thiocolchicine as compared with colchicine in biological assays probably derives from their more rapid binding to tubulin and the lower free energies of their binding reactions

Acidolysis small molecular phenolic ether used as accelerator in photosensitive diazonaphthaquinone systems

Science.gov (United States)

Zhou, Haihua; Zou, Yingquan

2006-03-01

The photosensitive compounds in the photosensitive coatings of positive PS plates are the diazonaphthaquinone derivatives. Some acidolysis small molecular phenolic ethers, which were synthesized by some special polyhydroxyl phenols with vinyl ethyl ether, are added in the positive diazonaphthaquinone photosensitive composition to improve its sensitivity, composed with photo-acid-generators. The effects to the photosensitivity, anti-alkali property, anti-isopropyl alcohol property, dot resolution and line resolution of the coatings are studied with different additive percent of the special phenolic ethers. In the conventional photosensitive diazonaphthaquinone systems for positive PS plates, the photosensitivity is improved without negative effects to resolution, anti-alkali and anti-isopropyl alcohol properties when added about 5% of the special acidolysis phenolic ethers, EAAE or DPHE, composed with photo-acid-generators.

The simple ethers of glycerin

International Nuclear Information System (INIS)

Kimsanov, B.Kh.; Karimov, M.B.

1998-01-01

From glycerin derivatives the considerable interest is present simple ethers because many of them are biological active and found wide practical using as an effect drugs, inters for thin organic synthesis, vehicle for injections, regulators of plants growth, reagents, components for perfumery-cosmetic goods and etc

The PROMETHEE multiple criteria decision making analysis for selecting the best membrane prepared from sulfonated poly(ether ketone)s and poly(ether sulfone)s for proton exchange membrane fuel cell

International Nuclear Information System (INIS)

Nikouei, Mohammad Ali; Oroujzadeh, Maryam; Mehdipour-Ataei, Shahram

2017-01-01

Proton exchange membrane as the heart of fuel cell has been the topic of many research activities in recent years. Finding a suitable alternative for Nafion membranes is one of the most important issues of interest. This study is dedicated to sulfonated poly(ether ketone) and poly(ether sulfone) membranes. For synthesis of these two groups of polymers, two different isomeric biphenols (meta- and para-) were used and each group of membranes with three different degree of sulfonation (25, 35, and 45%) was synthesized. In this way, twelve different membrane samples were obtained and their properties were evaluated. Since each membrane had some strong and some weak points of properties in comparison to the other ones, using a rational analysis for choosing the best membrane between prepared samples was inevitable. For this purpose a PROMETHEE based multiple criteria decision making approach was applied and for evaluation of the weight of each criterion, Shannon entropy method was used. Final results showed that poly(ether ketone) membranes in selected criteria were better than poly(ether sulfone) membranes and as expected, membranes with the highest degree of sulfonation (45%) were placed at the top ranking levels. - Highlights: • Sulfonated poly(ether ketone)s and Poly(ether sulfone)s were synthesized. • Related membranes for PEMFC were prepared. • The properties of membranes were measured. • Multiple criteria decision making approach was used to ranking the membranes. • PROMETHEE based approach selected poly(ether ketone)s as better choices.

Contemporary 14C radiocarbon levels of oxygenated polybrominated diphenyl ethers (O-PBDEs) isolated in sponge-cyanobacteria associations

International Nuclear Information System (INIS)

Guitart, Carlos; Slattery, Marc; Ankisetty, Sridevi; Radwan, Mohamed; Ross, Samir J.; Letcher, Robert J.; Reddy, Christopher M.

2011-01-01

Research highlights: → O-PBDEs in the marine environment could have both natural and anthropogenic origin. → Molecular-level 14 C is measured by accelerated mass spectrometry. → Industrial products, derived from fossil sources, are radiocarbon 14 C-free. → O-PBDEs compounds from marine sponges show modern levels of 14 C. → Some species could produce O-PBDEs rather than being biotransformation from industrial PBDEs. - Abstract: Considerable debate surrounds the sources of oxygenated polybrominated diphenyl ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from anthropogenic industrial activities. Natural radiocarbon ( 14 C) abundance has proven to be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas industrial chemicals, mostly produced from fossil fuels, contain no detectable 14 C. However, few compounds isolated from organisms have been analyzed for their radiocarbon content. To provide a baseline, we analyzed the 14 C content of four O-PBDEs. These compounds, 6-OH-BDE47, 2'-OH-BDE68, 2',6-diOH-BDE159, and a recently identified compound, 2'-MeO-6-OH-BDE120, were isolated from the tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern radiocarbon content of their chemical structures (i.e. diphenyl ethers, C 12 H 22 O) indicates that they are naturally produced. This adds to a growing baseline on, at least, the sources of these unusual compounds.

Preparation of poly(ether ether ketone)-based polymer electrolytes for fuel cell membranes using grafting technique

International Nuclear Information System (INIS)

Hasegawa, Shin; Suzuki, Yasuyuki; Maekawa, Yasunari

2008-01-01

Poly(ether ether ketone) (PEEK)-based polymer electrolyte membranes (PEMs) was successfully prepared by radiation grafting of a styrene monomer into PEEK films and the consequent selective sulfonation of the grafting chains in the film state. Using milder sulfonation, the sulfonation reactions proceeded at the grafted chains in preference to the phenylene rings of PEEK main chains; as a result, the grafted films could successfully transform to a PEM with conductivity of more than 0.1 S/cm. The ion exchange capacity (IEC) and conductivity of the grafted PEEK electrolyte membranes were controlled to the ranges of 1.2-2.9 mmol/g and 0.03-0.18 S/cm by changing the grafting degree. It should be noted that this is the first example of directly transforming super-engineering plastic films into a PEM using radiation grafting

Sulfonated Poly(Ether Ether Ketone)/Functionalized Carbon Nanotube Composite Membrane for Vanadium Redox Flow Battery Applications

International Nuclear Information System (INIS)

Jia, Chuankun; Cheng, Yuanhang; Ling, Xiao; Wei, Guanjie; Liu, Jianguo; Yan, Chuanwei

2015-01-01

A novel sulfonated poly(ether ether ketone) (SPEEK) membrane embedded with the short-carboxylic multi-walled carbon nanotube (we name it as SPEEK/SCCT membrane) for vanadium redox flow battery (VRB) has been prepared with low capacity loss, low cost and high energy efficiency. The mechanical strength, vanadium ions permeability and performance of the membrane in the VRB single cell were characterized. Results showed that the SPEEK/SCCT membrane possessed low permeability of vanadium ions, accompanied by higher mechanical strength than the Nafion 212 membrane. The VRB single cell with SPEEK/SCCT membrane showed 7% higher coulombic efficiency (CE), 6% higher energy efficiency (EE) but lower capacity loss in comparison with the one with Nafion 212. The good cell performance, low capacity loss and high vanadium ions barrier properties of the blend membrane is of significant interest for VRB applications

PEEK (polyether-ether-ketone)-coated nitinol wire: Film stability for biocompatibility applications

Science.gov (United States)

Sheiko, Nataliia; Kékicheff, Patrick; Marie, Pascal; Schmutz, Marc; Jacomine, Leandro; Perrin-Schmitt, Fabienne

2016-12-01

High quality biocompatible poly-ether-ether-ketone (PEEK) coatings were produced on NiTi shape memory alloy wires using dipping deposition from colloidal aqueous PEEK dispersions after substrate surface treatment. The surface morphology and microstructure were investigated by Scanning Electron Microscopy at every step of the process from the as-received Nitinol substrate to the ultimate PEEK-coated NiTi wire. Nanoscratch tests were carried out to access the adhesive behavior of the polymer coated film to the NiTi. The results indicate that the optimum process conditions in cleaning, chemical etching, and electropolishing the NiTi, were the most important and determining parameters to be achieved. Thus, high quality PEEK coatings were obtained on NiTi wires, straight or curved (even with a U-shape) with a homogeneous microstructure along the wire length and a uniform thickness of 12 μm without any development of cracks or the presence of large voids. The biocompatibility of the PEEK coating film was checked in fibrobast cultured cells. The coating remains stable in biological environment with negligible Ni ion release, no cytotoxicity, and no delamination observed with time.

Influence of structure of crown ethers on their radiation stability

International Nuclear Information System (INIS)

Grigor'ev, E.I.; Myasoedova, T.G.; Nesterov, S.V.; Trakhtenberg, L.I.

1988-01-01

Primary products of γ-radiolysis of crown ethers with the same size of the macrocyclic ring and different substituents were studied by EPR and mass spectrometry. It was shown that introduction of substituents into the polyether ring increases the radiation stability of crown ethers due to intramolecular transfer of energy from the polyether ring to a substituent

THE KINETICS OF METHYL METHACRYLATE POLYMERIZATION INITIATED BY THE VOLATILE PRODUCTS OF A METHYL METHACRYLATE PLASMA

Institute of Scientific and Technical Information of China (English)

杨梅林; 马於光; 郑莹光; 沈家骢

1990-01-01

It is found that the volatile products of methyl methacrylate plasma can very actively initiate the polymerization of the monomer to produce ultrahigh molecular weight polymers. This polymerization of MMA occurs by a livlng free radical mechanism with instantaneous initiation and monomer transfer.

Degradation of Perfluorinated Ether Lubricants on Pure Aluminum Surfaces: Semiempirical Quantum Chemical Modeling

Science.gov (United States)

Slaby, Scott M.; Ewing, David W.; Zehe, Michael J.

1997-01-01

The AM1 semiempirical quantum chemical method was used to model the interaction of perfluoroethers with aluminum surfaces. Perfluorodimethoxymethane and perfluorodimethyl ether were studied interacting with aluminum surfaces, which were modeled by a five-atom cluster and a nine-atom cluster. Interactions were studied for edge (high index) sites and top (low index) sites of the clusters. Both dissociative binding and nondissociative binding were found, with dissociative binding being stronger. The two different ethers bound and dissociated on the clusters in different ways: perfluorodimethoxymethane through its oxygen atoms, but perfluorodimethyl ether through its fluorine atoms. The acetal linkage of perfluorodimeth-oxymethane was the key structural feature of this molecule in its binding and dissociation on the aluminum surface models. The high-index sites of the clusters caused the dissociation of both ethers. These results are consistent with the experimental observation that perfluorinated ethers decompose in contact with sputtered aluminum surfaces.

Synthesis and evaluation of 1,4-naphthoquinone ether derivatives as SmTGR inhibitors and new anti-schistosomal drugs.

Science.gov (United States)

Johann, Laure; Belorgey, Didier; Huang, Hsin-Hung; Day, Latasha; Chessé, Matthieu; Becker, Katja; Williams, David L; Davioud-Charvet, Elisabeth

2015-08-01

Investigations regarding the chemistry and mechanism of action of 2-methyl-1,4-naphthoquinone (or menadione) derivatives revealed 3-phenoxymethyl menadiones as a novel anti-schistosomal chemical series. These newly synthesized compounds (1-7) and their difluoromethylmenadione counterparts (8, 9) were found to be potent and specific inhibitors of Schistosoma mansoni thioredoxin-glutathione reductase (SmTGR), which has been identified as a potential target for anti-schistosomal drugs. The compounds were also tested in enzymic assays using both human flavoenzymes, i.e. glutathione reductase (hGR) and selenium-dependent human thioredoxin reductase (hTrxR), to evaluate the specificity of the inhibition. Structure-activity relationships as well as physico- and electro-chemical studies showed a high potential for the 3-phenoxymethyl menadiones to inhibit SmTGR selectively compared to hGR and hTrxR enzymes, in particular those bearing an α-fluorophenol methyl ether moiety, which improves anti-schistosomal action. Furthermore, the (substituted phenoxy)methyl menadione derivative (7) displayed time-dependent SmTGR inactivation, correlating with unproductive NADPH-dependent redox cycling of SmTGR, and potent anti-schistosomal action in worms cultured ex vivo. In contrast, the difluoromethylmenadione analog 9, which inactivates SmTGR through an irreversible non-consuming NADPH-dependent process, has little killing effect in worms cultured ex vivo. Despite ex vivo activity, none of the compounds tested was active in vivo, suggesting that the limited bioavailability may compromise compound activity. Therefore, future studies will be directed toward improving pharmacokinetic properties and bioavailability. © 2015 FEBS.

Early steps of biosynthesis of ether lipids in archaebacteria; Eteru shishitsu seigosei no shoki dankai

Energy Technology Data Exchange (ETDEWEB)

Nishino, T. [Tohoku Univ., Sendai (Japan). Faculty of Engineering

1997-05-20

Membrane lipids in archaebacteria are different from those of eubacteria and eukaryote which are fatty acid esters of glycerol. Archaebacterial lipids are mainly ether-linked lipids composed of glycerol linked to two molecules of isoprenoid phytanyl groups or of ether-linked glycerol with phytanyl group. This structural feature is one of the origins of survival and growth of archaebacteria in extreme conditions of high temperature, strong acid or alkali. It is considered that geranylgeranyl phosphate (GGPP) is synthesized and attached to glycerol phosphate, followed by reduction of the double bond in the geranylgeranyl moieties to form the diether lipids while the head-to-heat condensation of the phytanyl groups produces the tetraether lipids. Aiming to elucidate the lipid biosynthesis mechanism in a hyperthermophilic archaebacterium, Sulfolobus acidocaldarius, the gene of GGPP synthase was cloned with the aid of carotenoid synthesis in phytopathogenic Erwinia uredovora and its sequence was studied. 29 refs., 9 figs.

Peter J Derrick and the Grand Scale 'Magnificent Mass Machine' mass spectrometer at Warwick.

Science.gov (United States)

Colburn, A W; Derrick, Peter J; Bowen, Richard D

2017-12-01

The value of the Grand Scale 'Magnificent Mass Machine' mass spectrometer in investigating the reactivity of ions in the gas phase is illustrated by a brief analysis of previously unpublished work on metastable ionised n-pentyl methyl ether, which loses predominantly methanol and an ethyl radical, with very minor contributions for elimination of ethane and water. Expulsion of an ethyl radical is interpreted in terms of isomerisation to ionised 3-pentyl methyl ether, via distonic ions and, possibly, an ion-neutral complex comprising ionised ethylcyclopropane and methanol. This explanation is consistent with the closely similar behaviour of the labelled analogues, C 3 H 7 CH 2 CD 2 OCH 3 +. and C 3 H 7 CD 2 CH 2 OCH 3 +. , and is supported by the greater kinetic energy release associated with loss of ethane from ionised n-propyl methyl ether compared to that starting from directly generated ionised 3-pentyl methyl ether.

Increasing the thermopower of crown-ether-bridged anthraquinones

Science.gov (United States)

Ismael, Ali K.; Grace, Iain; Lambert, Colin J.

2015-10-01

We investigate strategies for increasing the thermopower of crown-ether-bridged anthraquinones. The novel design feature of these molecules is the presence of either (1) crown-ether or (2) diaza-crown-ether bridges attached to the side of the current-carrying anthraquinone wire. The crown-ether side groups selectively bind alkali-metal cations and when combined with TCNE or TTF dopants, provide a large phase-space for optimising thermoelectric properties. We find that the optimum combination of cations and dopants depends on the temperature range of interest. The thermopowers of both 1 and 2 are negative and at room temperature are optimised by binding with TTF alone, achieving thermpowers of -600 μV K-1 and -285 μV K-1 respectively. At much lower temperatures, which are relevant to cascade coolers, we find that for 1, a combination of TTF and Na+ yields a maximum thermopower of -710 μV K-1 at 70 K, whereas a combination of TTF and Li+ yields a maximum thermopower of -600 μV K-1 at 90 K. For 2, we find that TTF doping yields a maximum thermopower of -800 μV K-1 at 90 K, whereas at 50 K, the largest thermopower (of -600 μV K-1) is obtain by a combination TTF and K+ doping. At room temperature, we obtain power factors of 73 μW m-1 K-2 for 1 (in combination with TTF and Na+) and 90 μW m-1 K-2 for 2 (with TTF). These are higher or comparable with reported power factors of other organic materials.We investigate strategies for increasing the thermopower of crown-ether-bridged anthraquinones. The novel design feature of these molecules is the presence of either (1) crown-ether or (2) diaza-crown-ether bridges attached to the side of the current-carrying anthraquinone wire. The crown-ether side groups selectively bind alkali-metal cations and when combined with TCNE or TTF dopants, provide a large phase-space for optimising thermoelectric properties. We find that the optimum combination of cations and dopants depends on the temperature range of interest. The

Development and characterization of poli composites (ether ether ketone)(PEEK)(Hydroxyapatite(HA)

International Nuclear Information System (INIS)

Ferreira, V.P.; Santos, F.S.F.; Sa, M.D. de; Fook, M.V.L.

2016-01-01

The objective of this work was to develop PEEK / HA composites, combining the biological activity of the ceramic phase with the properties of the polymer phase, the materials used in this research were Poly (ether-ether-ketone) (PEEK) and Hydroxyapatite (HA) (50, 60, 70 and 80% m / v HA), this material was subjected to a load of two tons followed by a thermal treatment at 390 ° for a period of 30 minutes. Then they were characterized by FTIR, DRX and MO. In the physical-chemical characterization of FTIR and XRD, it was not possible to identify significant alterations. In the FTIR spectra of the composites, there is no formation of new identifiable chemical bonds. In the composites XRD diffractograms a profile similar to the ceramic phase was observed, with peaks increasing in intensity and narrowing proportional to the increase of the hydroxyapatite concentration in the composites. In optical microscopy it is possible to observe surfaces with heterogeneous morphology, with signs of roughness and in the cross section we observe a heterogeneous aspect, rich in regions with large agglomerates and lighter particles. Considering the processing aspects, the technique proved to be effective for the development of PEEK /HA composites. (author)

Preliminary studies of the toxic effects of non-ionic surfactants derived from lysine.

Science.gov (United States)

Macián, M; Seguer, J; Infante, M R; Selve, C; Vinardell, M P

1996-01-08

The toxic effects of new synthetic monodisperse non-ionic long-chain N alpha, N epsilon-diacyl lysine polyoxyethylene glycol amide compounds with a structural resemblance to natural lecithin phospholipids were studied by the haemolytic method and the test of the chorioallantoic membrane of the hen's egg (HET-CAM). The following compounds were tested: symmetrical N alpha,N epsilon-diacyl lysine homologues (N alpha,N epsilon-dihexanoyl, N alpha,N epsilon-dioctanoyl and N alpha,N epsilon-didecanoyl lysine) with one methyl ether polyoxyethylene glycol chain of different oxyethylene units (dioxyethylene glycol, tetraoxyethylene glycol and hexaoxyethylene glycol) as headgroup; symmetrical N alpha,N epsilon-diacyl lysine homologues with two methyl ether dioxyethylene glycol chains and the asymmetrical N alpha-butanoyl, N epsilon-dodecyl lysine with two hydrophilic methyl ether dioxyethylene glycol chains as headgroup. A commercial (polydisperse) oleoyl polyoxyethylene glycol diethanolamide with an average of eight units of ethylene oxide was used as control. All the synthesized tested compounds appeared to be less haemolytic and less irritant than the control. The synthesized products were studied with regard to their hydrophobic and hydrophilic chains in order to evaluate the influence of their structure on their haemolytic and irritative action. The results of this study show that the acyl chain distribution of these compounds greatly influence toxic effects: the asymmetrical compound N alpha-butanoyl,N epsilon-dodecyl lysine-bis[methyl ether diethylene glycol]amide was found to be the most haemolytic and irritating compound. Among the symmetrical homologues, the shortest-chain compounds N alpha,N epsilon-dihexanoyl lysine methyl ether polyoxyethylene glycol amides present the least haemolytic and irritating activity, independently of the number and length of the hydrophilic methyl ether polyoxyethylene glycol chains. Taking into account their surface activity

A novel sulfonated poly(ether ether ketone) and cross-linked membranes for fuel cells

Energy Technology Data Exchange (ETDEWEB)

Li, Hongtao; Zhang, Gang; Wu, Jing; Zhao, Chengji; Zhang, Yang; Shao, Ke; Han, Miaomiao; Lin, Haidan; Zhu, Jing; Na, Hui [Alan G MacDiarmid Institute, College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, Jilin (China)

2010-10-01

A novel poly(ether ether ketone) (PEEK) containing pendant carboxyl groups has been synthesized by a nucleophilic polycondensation reaction. Sulfonated polymers (SPEEKs) with different ion exchange capacity are then obtained by post-sulfonation process. The structures of PEEK and SPEEKs are characterized by both FT-IR and {sup 1}H NMR. The properties of SPEEKs as candidates for proton exchange membranes are studied. The cross-linking reaction is performed at 140 C using poly(vinyl alcohol) (PVA) as the cross-linker. In comparison with the non-cross-linked membranes, some properties of the cross-linked membranes are significantly improved, such as water uptake, methanol resistance, mechanical and oxidative stabilities, while the proton conductivity decreases. The effect of PVA content on proton conductivity, water uptake, swelling ratio, and methanol permeability is also investigated. Among all the membranes, SPEEK-C-8 shows the highest selectivity of 50.5 x 10{sup 4} S s cm{sup -3}, which indicates that it is a suitable candidate for applications in direct methanol fuel cells. (author)

Ether gas-sensor based on Au nanoparticles-decorated ZnO microstructures

Directory of Open Access Journals (Sweden)

Roberto López

Full Text Available An ether gas-sensor was fabricated based on gold nanoparticles (Au-NPs decorated zinc oxide microstructures (ZnO-MS. Scanning electron microscope (SEM and high-resolution transmission electron microscope (HRTEM measurements were performed to study morphological and structural properties, respectively, of the ZnO-MS. The gas sensing response was evaluated in a relatively low temperature regime, which ranged between 150 and 250 °C. Compared with a sensor fabricated from pure ZnO-MS, the sensor based on Au-NPs decorated ZnO-MS showed much better ether gas response at the highest working temperature. In fact, pure ZnO-MS based sensor only showed a weak sensitivity of about 25%. The improvement of the ether gas response for sensor fabricated with Au-NPs decorated ZnO-MS was attributed to the catalytic activity of the Au-NPs. Keywords: ZnO microstructures, Au nanoparticles, Ether, Gas sensor

Biomedical potentials of crown ethers: prospective antitumor agents.

Science.gov (United States)

Kralj, Marijeta; Tusek-Bozić, Ljerka; Frkanec, Leo

2008-10-01

Crown ethers are of enormous interest and importance in chemistry, biochemistry, materials science, catalysis, separation, transport and encapsulated processes, as well as in the design and synthesis of various synthetic systems with specific properties, diverse capabilities, and programmable functions. Classical crown ethers are macrocyclic polyethers that contain 3-20 oxygen atoms separated from each other by two or more carbon atoms. They are exceptionally versatile in selectively binding a range of metal ions and a variety of organic neutral and ionic species. Crown ethers are currently being studied and used in a variety of applications beyond their traditional place in chemistry. This review presents additional applications and the ever-increasing biomedical potentials of these intriguing compounds, with particular emphasis on the prospects of their relevance as anticancer agents. We believe that further research in this direction should be encouraged, as crown compounds could either induce toxicities that are different from those of conventional antitumor drugs, or complement drugs in current use, thereby providing a valuable adjunct to therapy.

Perfluorocyclobutane containing aromatic ether polymers as planarization materials for alternative magnetic media substrates

Science.gov (United States)

Perettie, Donald J.; Judy, Jack; Chen, Qixu; Keirstead, Rick

1994-11-01

Perfluorocyclobutane aromatic ether polymers (PFCB) are being researched as planarization materials for alternative magnetic media substrates allowing smoother surfaces for lower head flying recording. The results of current work reported herein have shown that PFCB can be used to affect surfaces on canasite with R(sub A)'s less than 2 nm. In addition, magnetic media can be produced of a quality comparative to that obtained on standard NiP-coated Al as well as that produced on regular canasite with equivalent coercivities at about 1500-1600 Oe and squarenesses of 0.8 or better. In addition to the above magnetic properties the recording performance was excellent with signal-to-noise ratios of planarized media 3.5 dB higher than that on regular canasite.

Proton-conducting membranes based on benzimidazole-containing sulfonated poly(ether ether ketone) compared with their carboxyl acid form

Energy Technology Data Exchange (ETDEWEB)

Li, Hongtao; Wu, Jing; Zhao, Chengji; Zhang, Gang; Zhang, Yang; Shao, Ke; Xu, Dan; Lin, Haidan; Han, Miaomiao; Na, Hui [Alan G MacDiarmid Institute, College of Chemistry, Jilin University, Changchun 130012 (China)

2009-10-15

A series of sulfonated poly(ether ether ketone) containing pendant carboxyl (C-SPEEKs) have been synthesized using a nucleophilic polycondesation reaction. A condensation reaction between 1,2-diaminobenzene and carboxyl resulted in a new series of copolymers containing benzimidazole groups (SPEEK-BIms). The expected structures of the sulfonated copolymers are confirmed by {sup 1}H NMR. The dependence of ion exchange capacity, water uptake, proton conductivity and methanol diffusion coefficient of SPEEK-BIm membranes has been studied and compared with their carboxyl acid form. The results suggest that the introduction of benzimidazole groups may be responsible for many excellent properties of the membranes for fuel cell. It is noticeable that the markedly improved oxidative stability is benefit for the application of membrane. (author)

Identification of Differentially Methylated Sites with Weak Methylation Effects

Directory of Open Access Journals (Sweden)

Hong Tran

2018-02-01

Full Text Available Deoxyribonucleic acid (DNA methylation is an epigenetic alteration crucial for regulating stress responses. Identifying large-scale DNA methylation at single nucleotide resolution is made possible by whole genome bisulfite sequencing. An essential task following the generation of bisulfite sequencing data is to detect differentially methylated cytosines (DMCs among treatments. Most statistical methods for DMC detection do not consider the dependency of methylation patterns across the genome, thus possibly inflating type I error. Furthermore, small sample sizes and weak methylation effects among different phenotype categories make it difficult for these statistical methods to accurately detect DMCs. To address these issues, the wavelet-based functional mixed model (WFMM was introduced to detect DMCs. To further examine the performance of WFMM in detecting weak differential methylation events, we used both simulated and empirical data and compare WFMM performance to a popular DMC detection tool methylKit. Analyses of simulated data that replicated the effects of the herbicide glyphosate on DNA methylation in Arabidopsis thaliana show that WFMM results in higher sensitivity and specificity in detecting DMCs compared to methylKit, especially when the methylation differences among phenotype groups are small. Moreover, the performance of WFMM is robust with respect to small sample sizes, making it particularly attractive considering the current high costs of bisulfite sequencing. Analysis of empirical Arabidopsis thaliana data under varying glyphosate dosages, and the analysis of monozygotic (MZ twins who have different pain sensitivities—both datasets have weak methylation effects of <1%—show that WFMM can identify more relevant DMCs related to the phenotype of interest than methylKit. Differentially methylated regions (DMRs are genomic regions with different DNA methylation status across biological samples. DMRs and DMCs are essentially the same

Protective effects of ether, oxygen and their mixture for radiation in Drosophila melanogaster

International Nuclear Information System (INIS)

Megumi, Tsuneo; Tsujii, Yukio; Gamo, Sumiko

1992-01-01

Protective effects of ether mixed with air or oxygen against ionizing radiation damages were demonstrated in adult flies of Drosophila melanogaster. The protective effects against knock-down on the second day and lethality on the eighth day after irradiation were not affected by the radiation sensitivity and DNA repair capacity of the strains. Ether (4.2%) in oxygen was more effective than ether in air for both endpoints. The protective effects may be due to damages not involving cell division, since no mitotic cells are observed in adult flies except in gonadal glands. A change in the orderliness of the cell membrane by ether is suggested to be the cause of the protective effects. (author). 16 refs.; 3 tabs

Radiolytic decomposition of 4-bromodiphenyl ether

International Nuclear Information System (INIS)

Tang Liang; Xu Gang; Wu Wenjing; Shi Wenyan; Liu Ning; Bai Yulei; Wu Minghong

2010-01-01

Polybrominated diphenyl ethers (PBDEs) spread widely in the environment are mainly removed by photochemical and anaerobic microbial degradation. In this paper, the decomposition of 4-bromodiphenyl ether (BDE -3), the PBDEs homologues, is investigated by electron beam irradiation of its ethanol/water solution (reduction system) and acetonitrile/water solution (oxidation system). The radiolytic products were determined by GC coupled with electron capture detector, and the reaction rate constant of e sol - in the reduction system was measured at 2.7 x 10 10 L · mol -1 · s -1 by pulsed radiolysis. The results show that the BDE-3 concentration affects strongly the decomposition ratio in the alkali solution, and the reduction system has a higher BDE-3 decomposition rate than the oxidation system. This indicates that the BDE-3 was reduced by effectively capturing e sol - in radiolytic process. (authors)

Spino ether and its vortices: leptons and hadrons

Energy Technology Data Exchange (ETDEWEB)

Skorski, R [College of Engineering, Univ. of Alabama, Alabama (USA)

1977-03-01

According to the theory advanced by the author, space is occupied by a spino ether lattice. Where no spino lattice exists, there are black holes. The spino is a kind of massive neutrino with a rest mass of about 7.39x10/sup -47/g and a diameter of 4.56x10/sup -34/cm. The distance between spinos in the spino lattice is about 2x10/sup -10/cm. Spino ether is ubiquitous in all matter, pervades atoms and their nuclei and penetrates matter with no resistance. In fact, hadrons and leptons are shown to be vortices of the spino ether. About one km/sup 3/ of space contains spino ether having a mass equal to 10/sup 80/ baryons, equivalent to the total mass of our universe. If the distances between spinos equaled their diameters, 4.56x10/sup -34/cm instead of 2x10/sup -10/cm, then the diameter of the mass equivalent to our universe would be about 2cm. This is in agreement with the size of the premordial universe, before its explosion, as calculated earlier by other theories. It is conjectured that explosions of energy and mass in space are more frequent on a smaller scale than those in the universe, for example novas, or even on a still smaller scale usually associated with the birth of different nuclei. The abundance of iron in the solar corona, on the surface of Mars, and in the Martin sky appears to be due to hadron formation from space itself.

Dimethylzinc-Initiated Radical Coupling of β-Bromostyrenes with Ethers and Amines

DEFF Research Database (Denmark)

Sølvhøj, Amanda Birgitte; Ahlburg, Andreas; Madsen, Robert

2015-01-01

A new coupling reaction has been developed in which β-bromostyrenes react with ethers and tertiary amines to introduce the styryl group in the α-position. The transformation is mediated by Me2Zn/O2 with 10 % MnCl2 and is believed to proceed by a radical addition-elimination mechanism. The ether...... and the amine are employed as solvent and the coupling takes place through the most stable α radical for unsymmetrical substrates. The products are obtained in moderate to good yields as the pure E isomers. The coupling can be achieved with a range of smaller cyclic and acyclic ethers/amines as well as various...

Effect of the methyl gallate on the damage produced by radiation in leucocytes of peripheral blood of In vivo mouse

International Nuclear Information System (INIS)

Zarco M, A.

2007-01-01

The ionizing radiation produces a great variety of lesions in the deoxyribonucleic acid (DNA) through the formation of free radicals (RL), reason why the study about those made up with possible radioprotective property has been increased. The methyl gallate (MeG) it is an antioxidant derived of plants with capacity to capture RL. The objective of the present work was to determine the effect of the methyl gallate on the damage in the DNA taken place by gamma radiation in leukocytes of peripheral blood of in vivo mouse. The experimental design consisted of 4 groups of mice: It has a witness of the solvent group, dimethylsulfoxide (DMSO), in which was administer by intraperitoneal via 0.4 mL of a solution 1:8 of DMSO: H 2 O; a second group, denominated MeG witness, it was administered intraperitoneally with a dose of 0.1 μ moles/g of weight. Another group was used as radiation witness, reason why it was only treated with 1 Gray (Gy) of gamma radiation coming from a cobalt 60 source. At last, the group denominated problem it was administered with 0.1 μ moles of MeG/g of corporal weight 30 previous minutes to the irradiation with 1 Gy. In the comparison of the damage and repair curves obtained with the unicellular in gel electrophoresis technique among the irradiated groups, it was determined that there is one significant reduction of 15% in the DNA damage observed to the two minutes postradiation in the problem group with respect to the radiation witness. It was concluded that this decrease is due to the antioxidant effect of the methyl gallate and that therefore this compound has possibilities to act as radioprotector. (Author)

Poly (ether ether ketone) membranes for fuel cells; Membranas de poli (eter eter cetona) sulfonado para celulas a combustivel

Energy Technology Data Exchange (ETDEWEB)

Marrero, Jacqueline C.; Gomes, Ailton de S.; Filho, Jose C.D., E-mail: jacquecosta@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Hui, Wang S. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil); Oliveira, Vivianna S. de [Escola Tecnica Rezende-Rammel, Rio de Janeiro, RJ (Brazil)

2015-07-01

Polymeric membranes were developed using a SPEEK polymer matrix (sulphonated poly (ether ether ketone)), containing hygroscopic particles of zirconia (Zr) (incorporated by sol-gel method), for use as electrolyte membranes in fuel cells. SPEEK with different sulfonation degrees were used: 63 and 86%. The thermal analysis (TGA and DSC) was carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS) was carried out to evaluating the proton conductivity of the membranes. Additional analysis were underway in order to characterize these membranes, which include: X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to evaluate the influence of zirconia and sulfonation degree on the properties of the membranes. (author)

Flow Synthesis of 2-Methylpyridines via α-Methylation

Directory of Open Access Journals (Sweden)

Camille Manansala

2015-08-01

Full Text Available A series of simple 2-methylpyridines were synthesized in an expedited and convenient manner using a simplified bench-top continuous flow setup. The reactions proceeded with a high degree of selectivity, producing α-methylated pyridines in a much greener fashion than is possible using conventional batch reaction protocols. Eight 2-methylated pyridines were produced by progressing starting material through a column packed with Raney® nickel using a low boiling point alcohol (1-propanol at high temperature. Simple collection and removal of the solvent gave products in very good yields that were suitable for further use without additional work-up or purification. Overall, this continuous flow method represents a synthetically useful protocol that is superior to batch processes in terms of shorter reaction times, increased safety, avoidance of work-up procedures, and reduced waste. A brief discussion of the possible mechanism(s of the reaction is also presented which involves heterogeneous catalysis and/or a Ladenberg rearrangement, with the proposed methyl source as C1 of the primary alcohol.

Direct radioimmunoassay of 17. beta. -estradiol in ether extracts of bovine

Energy Technology Data Exchange (ETDEWEB)

Medina, M.B.

Anabolic estrogens such as 17..beta..-estradiol or 17..beta..-estradiol benzoate are used to promote growth and increase feed efficiency in food-producing cattle. This paper describes a technique to produce a more specific antibody to 17..beta..-estradiol by intradermal immunization using microquantities of 6-(carboxymethyl)-17..beta..-estradiol oxime bovine serum albumin and the development of a radioimmunoassay (RIA) procedure to measure directly the amounts of 17..beta..-estradiol in ether extracts of bovine serum without using cleanup procedures. Results demonstrated that a specific and sensitive antibody was produced, and a titer of 1:10,000 was used in the RIA procedure. Antibody cross-reactivity with ..beta..-estradiol metabolites and other anabolic estrogens was negligible. The untreated bovine sera showed 0-24 pg of apparent 17..beta..-estradiol/mL, while 0-31 pg/mL total estrogens had been reported in the literature. This assay can measure 5-100 pg in 20-250..mu..L/sample. This method can be used before or immediately after slaughter to monitor the residual amounts of estradiol used in the treatment of cattle.

Direct radioimmunoassay of 17β-estradiol in ether extracts of bovine

International Nuclear Information System (INIS)

Medina, M.B.

1986-01-01

Anabolic estrogens such as 17β-estradiol or 17β-estradiol benzoate are used to promote growth and increase feed efficiency in food-producing cattle. This paper describes a technique to produce a more specific antibody to 17β-estradiol by intradermal immunization using microquantities of 6-(carboxymethyl)-17β-estradiol oxime bovine serum albumin and the development of a radioimmunoassay (RIA) procedure to measure directly the amounts of 17β-estradiol in ether extracts of bovine serum without using cleanup procedures. Results demonstrated that a specific and sensitive antibody was produced, and a titer of 1:10,000 was used in the RIA procedure. Antibody cross-reactivity with β-estradiol metabolites and other anabolic estrogens was negligible. The untreated bovine sera showed 0-24 pg of apparent 17β-estradiol/mL, while 0-31 pg/mL total estrogens had been reported in the literature. This assay can measure 5-100 pg in 20-250μL/sample. This method can be used before or immediately after slaughter to monitor the residual amounts of estradiol used in the treatment of cattle

Isothermal Vapour-Liquid Equilibria in the Binary and Ternary Systems Composed of tert-Butyl Methyl Ether, 3,3-Dimethyl-2-butanone and 2,2-Dimethyl-1-propanol

Czech Academy of Sciences Publication Activity Database

Bernatová, Svatoslava; Pavlíček, Jan; Wichterle, Ivan

2009-01-01

Roč. 278, 1-2 (2009), s. 129-134 ISSN 0378-3812 R&D Projects: GA ČR GA104/07/0444 Institutional research plan: CEZ:AV0Z40720504 Keywords : alcohol * ether * ketone Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.857, year: 2009

Thermal and oxidative degradation studies of formulated C-ethers by gel-permeation chromatography

Science.gov (United States)

Jones, W. R., Jr.; Morales, W.

1982-01-01

Gel-permeation chromatography was used to analyze C-ether lubricant formulations from high-temperature bearing tests and from micro-oxidation tests. Three mu-styragel columns (one 500 and two 100 A) and a tetrahydrofuran mobile phase were found to adequately separate the C-ether degradation products. The micro-oxidation tests yielded degradation results qualitatively similar to those observed from the bearing tests. Micro-oxidation tests conducted in air yielded more degradation than did tests in nitrogen. No great differences were observed between the thermal-oxidative stabilities of the two C-ether formulations or between the catalytic degradation activities of silver and M-50 steel. C-ether formulation I did yield more degradation than did formulation II in 111- and 25-hour bearing tests, respectively.

The synthesis of carbon-14 labeled pravastatin

International Nuclear Information System (INIS)

Wallace, M.A.; Dean, D.C.; Ellsworth, R.L.; Melillo, D.G.; Marks, T.; White, R.F.

1993-01-01

An asymmetric route to [ 14 C]β-hydroxycompactin 1 bearing the (S)-2-methyl-[1- 14 C]butanoate side chain has been developed. Methylation of [N-[1- 14 C]butyryl]-4-(S)-phenylmethyl-2-oxazolidinone 4 afforded a 95:5 mixture of diastereomeric [N-(S,R)-2-methyl-[1- 14 C]butyryl]-4-(S)-phenylmethyl-2-oxazolidi nones 5,6 which were separated by preparative HPLC. Oxidative cleavage of 5 afforded optically pure (S)-2-methyl-[1- 14 C]butanoic acid. Acylation of alcohol 9 with optically pure (S)-2-methyl-[1- 14 C] butyryl chloride afforded ester 10. Removal of the silyl ether produced diastereomerically pure compactin 11. Hydroxylation was carried out by biotransformation with Mucor hiemelus to afford diastereomerically pure [[1- 14 C]butanoate]β-hydroxycompactin, [ 14 C]Pravastatin 1. (Author)

Direct dimethyl ether fueling of a high temperature polymer fuel cell

DEFF Research Database (Denmark)

Jensen, Jens Oluf; Vassiliev, Anton; Olsen, M.I.

2012-01-01

Direct dimethyl ether (DME) fuel cells suffer from poor DME–water miscibility and so far peak powers of only 20–40 mW cm−2 have been reported. Based on available literature on solubility of dimethyl ether (DME) in water at ambient pressure it was estimated that the maximum concentration of DME at...

Synthesis of Novel Bibrachial Lariat Ethers (BiBLEs) Containing [1,2 ...

African Journals Online (AJOL)

NICO

A practical and regioselective method for the synthesis of cis-diastereomers of bibrachial lariat ethers (BiBLEs) bearing ester and amide groups is reported. The novel bibrachial lariat ethers (BiBLEs) 3a–d with neutral side chains were prepared by reaction of the corresponding aza-crown macrocycles 1a–b with ethyl ...

Wettability, optical properties and molecular structure of plasma polymerized diethylene glycol dimethyl ether

Energy Technology Data Exchange (ETDEWEB)

Azevedo, T C A M; Algatti, M A; Mota, R P; Honda, R Y; Kayama, M E; Kostov, K G; Fernandes, R S [FEG-DFQ-UNESP, Av. Ariberto Pereira da Cunha 333, 12516-410 - Guaratingueta, SP (Brazil); Cruz, N C; Rangel, E C, E-mail: algatti@feg.unesp.b [UNESP, Avenida Tres de Marco, 511, 18087-180 Sorocaba, SP (Brazil)

2009-05-01

Modern industry has frequently employed ethylene glycol ethers as monomers in plasma polymerization process to produce different types of coatings. In this work we used a stainless steel plasma reactor to grow thin polymeric films from low pressure RF excited plasma of diethylene glycol dimethyl ether. Plasmas were generated at 5W RF power in the range of 16 Pa to 60 Pa. The molecular structure of plasma polymerized films and their optical properties were analyzed by Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet-Visible Spectroscopy, respectively. The IR spectra show C-H stretching at 3000-2900 cm{sup -1}, C=O stretching at 1730-1650 cm{sup -1}, C-H bending at 1440-1380 cm{sup -1}, C-O and C-O-C stretching at 1200-1000 cm{sup -1}. The refraction index was around 1.5 and the optical gap calculated from absorption coefficient presented value near 3.8 eV. Water contact angle of the films ranged from 40 deg. to 35 deg. with corresponding surface energy from 66 to 73x10{sup -7} J. Because of its favorable optical and hydrophilic characteristics these films can be used in ophthalmic industries as glass lenses coatings.

Metabolism of nitrodiphenyl ether herbicides by dioxin-degrading bacterium Sphingomonas wittichii RW1.

Science.gov (United States)

Keum, Young Soo; Lee, Young Ju; Kim, Jeong-Han

2008-10-08

Nitrodiphenyl ether herbicides, including chlomethoxyfen, nitrofen, and oxyfluorfen are potent herbicides. Some metabolites and parent compounds are considered as possible mutagens and endocrine disruptors. Both properties pose serious hygienic and environmental risks. Sphingomonas wittichii RW1 is a well-known degrader of polychlorinated dibenzo- p-dioxins, dibenzofurans, and diphenyl ethers. However, no detailed research of its metabolic activity has been performed against pesticides with a diphenyl ether scaffold. In this study, we report S. wittichii RW1 as a very potent diphenyl ether herbicide-metabolizing bacterium with broad substrate specificity. The structures of metabolites were determined by instrumental analysis and synthetic standards. Most pesticides were rapidly removed from the culture medium in the order of nitrofen > oxyfluorfen > chlomethoxyfen. In general, herbicides were degraded through the initial reduction and N-acetylation of nitro groups, followed by ether bond cleavage. Relatively low concentrations of phenolic and catecholic metabolites throughout the study suggested that these metabolites were rapidly metabolized and incorporated into primary metabolism. These results indicate that strain RW1 has very versatile metabolic activities over a wide range of environmental contaminants.

Children's exposure to polybrominated diphenyl ethers.

NARCIS (Netherlands)

Zuurbier, M.; Leijs, M.; Schoeters, G.; Tusscher, G. Ten; Koppe, J.G.

2006-01-01

Background: Polybrominated biphenyl ethers (PBDEs), a class of brominated flame retardants, are frequently used in consumer products. PBDEs levels in environmental and human samples have increased in recent decades. Children are exposed to PBDEs through diet, mainly through fish, meat and milk.

Whole-genome methylation caller designed for methyl- DNA ...

African Journals Online (AJOL)

etchie

2013-02-20

Feb 20, 2013 ... Our method uses a single-CpG-resolution, whole-genome methylation ... Key words: Methyl-DNA immunoprecipitation, next-generation sequencing, ...... methylation is prevalent in embryonic stem cells andmaybe mediated.

Novel methyl transfer during chemotaxis in Bacillus subtilis

International Nuclear Information System (INIS)

Thoelke, M.S.; Kirby, J.R.; Ordal, G.W.

1989-01-01

If Bacillus subtilis is incubated in radioactive methionine in the absence of protein synthesis, the methyl-accepting chemotaxis proteins (MCPs) become radioactively methylated. If the bacteria are further incubated in excess nonradioactive methionine (cold-chased) and then given the attractant aspartate, the MCPs lose about half of their radioactivity due to turnover, in which lower specific activity methyl groups from S-adenosylmethionine (AdoMet) replace higher specific activity ones. Due to the cold-chase, the specific activity of the AdoMet pool is reduced at least 2-fold. If, later, the attractant is removed, higher specific activity methyl groups return to the MCPs. Thus, there must exist an unidentified methyl carrier than can reversibly receive methyl groups from the MCPs. In a similar experiment, labeled cells were transferred to a flow cell and exposed to addition and removal of attractant and of repellent. All four kinds of stimuli were found to cause methanol production. Bacterial with maximally labeled MCPs were exposed to many cycles of addition and removal of attractant; the maximum amount of radioactive methanol was evolved on the third, not the first, cycle. This result suggests that there is a precursor-product relationship between methyl groups on the MCPs and on the unidentified carrier, which might be the direct source of methanol. However, since no methanol was produced when a methyltransferase mutant, whose MCPs were unmethylated, was exposed to addition and removal of attractant or repellent, the methanol must ultimately derive from methylated MCPs

Functional analysis of a tomato salicylic acid methyl transferase and its role in synthesis of the flavor volatile methyl salicylate.

Science.gov (United States)

Tieman, Denise; Zeigler, Michelle; Schmelz, Eric; Taylor, Mark G; Rushing, Sarah; Jones, Jeffrey B; Klee, Harry J

2010-04-01

Methyl salicylate (MeSA) is a volatile plant secondary metabolite that is an important contributor to taste and scent of many fruits and flowers. It is synthesized from salicylic acid (SA), a phytohormone that contributes to plant pathogen defense. MeSA is synthesized by members of a family of O-methyltransferases. In order to elaborate the mechanism of MeSA synthesis in tomato, we screened a set of O-methyltransferases for activity against multiple substrates. An enzyme that specifically catalyzes methylation of SA, SlSAMT, as well as enzymes that act upon jasmonic acid and indole-3-acetic acid were identified. Analyses of transgenic over- and under-producing lines validated the function of SlSAMT in vivo. The SlSAMT gene was mapped to a position near the bottom of chromosome 9. Analysis of MeSA emissions from an introgression population derived from a cross with Solanum pennellii revealed a quantitative trait locus (QTL) linked to higher fruit methyl salicylate emissions. The higher MeSA emissions associate with significantly higher SpSAMT expression, consistent with SAMT gene expression being rate limiting for ripening-associated MeSA emissions. Transgenic plants that constitutively over-produce MeSA exhibited only slightly delayed symptom development following infection with the disease-causing bacterial pathogen, Xanthomonas campestris pv. vesicatoria (Xcv). Unexpectedly, pathogen-challenged leaves accumulated significantly higher levels of SA as well as glycosylated forms of SA and MeSA, indicating a disruption in control of the SA-related metabolite pool. Taken together, the results indicate that SlSAMT is critical for methyl salicylate synthesis and methyl salicylate, in turn, likely has an important role in controlling SA synthesis.

Mechanical properties and chemical stability of pivalolactone-based poly(ether ester)s

NARCIS (Netherlands)

Tijsma, E.J.; Tijsma, E.J.; van der Does, L.; Bantjes, A.; Bantjes, A.; Vulic, I.

1994-01-01

The processing, mechanical and chemical properties of poly(ether ester)s, prepared from pivalolactone (PVL), 1,4-butanediol (4G) and dimethyl terephthalate (DMT), were studied. The poly(ether ester)s could easily be processed by injection moulding, owing to their favourable rheological and thermal

Polybrominated diphenyl ethers in articles: a review of its applications and legislation.

Science.gov (United States)

Jinhui, Li; Yuan, Chen; Wenjing, Xiao

2017-02-01

Polybrominated diphenyl ethers (PBDEs), especially commercial decabrominated diphenyl ethers (c-decaBDE), have been widely produced and applied to numerous materials because of their highly effective flame-retardant capabilities. The production of commercial pentaBDE (c-pentaBDE) and commercial octaBDE (c-octaBDE) ended in 2004 because they are persistent, bioaccumulative, and toxic to both humans and the environment, but decaBDE production and use continue. Furthermore, many congeners of PBDEs are still prevalent in consumer products and articles that they pose enormous threat to both the environment and human health. PBDEs have been detected in the casing of electrical and electronic equipment, textile materials, automotive interiors, polyurethane foam (PUF) in seat cushions, children's toys, kitchenware, and other products. With increasing evidence about PBDE pollution and the adoption of international conventions, many developed countries have drawn more public attention to PBDEs and developed sound strategies for their management. This review summaries the utilization and management of PBDEs in a number of countries and reaches the conclusion that PBDEs are still prevalent in consumer articles, while specific regulations or policies for articles containing PBDEs are rare. Public awareness should be raised on the importance of sound management of articles containing PBDEs.

Identification of endometrial cancer methylation features using combined methylation analysis methods.

Directory of Open Access Journals (Sweden)

Michael P Trimarchi

Full Text Available DNA methylation is a stable epigenetic mark that is frequently altered in tumors. DNA methylation features are attractive biomarkers for disease states given the stability of DNA methylation in living cells and in biologic specimens typically available for analysis. Widespread accumulation of methylation in regulatory elements in some cancers (specifically the CpG island methylator phenotype, CIMP can play an important role in tumorigenesis. High resolution assessment of CIMP for the entire genome, however, remains cost prohibitive and requires quantities of DNA not available for many tissue samples of interest. Genome-wide scans of methylation have been undertaken for large numbers of tumors, and higher resolution analyses for a limited number of cancer specimens. Methods for analyzing such large datasets and integrating findings from different studies continue to evolve. An approach for comparison of findings from a genome-wide assessment of the methylated component of tumor DNA and more widely applied methylation scans was developed.Methylomes for 76 primary endometrial cancer and 12 normal endometrial samples were generated using methylated fragment capture and second generation sequencing, MethylCap-seq. Publically available Infinium HumanMethylation 450 data from The Cancer Genome Atlas (TCGA were compared to MethylCap-seq data.Analysis of methylation in promoter CpG islands (CGIs identified a subset of tumors with a methylator phenotype. We used a two-stage approach to develop a 13-region methylation signature associated with a "hypermethylator state." High level methylation for the 13-region methylation signatures was associated with mismatch repair deficiency, high mutation rate, and low somatic copy number alteration in the TCGA test set. In addition, the signature devised showed good agreement with previously described methylation clusters devised by TCGA.We identified a methylation signature for a "hypermethylator phenotype" in

Flourimetric and prototropic studies on the inclusion complexation of 2-amino and 4-aminodiphenyl ethers with {beta}-cyclodextrin: Unusual behavior of 4-aminodiphenyl ether

Energy Technology Data Exchange (ETDEWEB)

Enoch, Israel V. Muthu Vijayan [Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu (India); Swaminathan, Meenakshisundaram [Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu (India)], E-mail: chemsam@yahoo.com

2007-12-15

The fluorescence characteristics of diphenyl ether (DPE), 2-aminodiphenyl ether (2ADPE) and 4-aminodiphenyl ether (4ADPE) and prototropic behavior of 2ADPE and 4ADPE on inclusion complexation with {beta}-cyclodextrin have been investigated. DPE forms 1:1 complex whereas 2ADPE and 4ADPE form 1:2 complex with {beta}-CDx. The fluorimetric and prototropic behaviors of 4ADPE in {beta}-CDx are different from those in aqueous solution. The dual fluorescence of 4ADPE in {beta}-CDx is found to be due to twisted intramolecular charge transfer (TICT) character induced by inclusion complexation. The two equilibria viz. monocation{r_reversible}monocation solvent exciplex{r_reversible}neutral reported for 4ADPE in aqueous solution are not observed in presence of {beta}-CDx. The ground and excited state pK{sub a} values for monocation-neutral equilibrium of 2ADPE and 4ADPE have been reported.

High Resolution Rotational Spectroscopy of a Flexible Cyclic Ether

Science.gov (United States)

Gámez, F.; Martínez-Haya, B.; Blanco, S.; López, J. C.; Alonso, J. L.

2011-06-01

Crown ethers stand as one cornerstone molecular class inhost-guest Supramolecular Chemistry and constitute building blocks for a broad range of modern materials. We report here the first high resolution rotational study of a crown ether: 1,4,7,10,13-pentaoxacyclopentadecane (15-crown-5 ether,15c5). Molecular beam Fourier transform microwave spectroscopy has been employed. The liquid sample of 15c5 has been vaporized using heating methods. The considerable size of 15c5 and the broad range of conformations allowed by the flexibility of its backbone pose important challenges to spectroscopy approaches. In fact, the ab-initio computational study for isolated 15c5, yields at least six stable conformers with relative free energies within 2 kJ Mol-1 (167 Cm-1). Nevertheless, in this investigation it has been possible to identify and characterize in detail one stable rotamer of the 15c5 molecule and to challenge different quantum methods for the accurate description of this system. The results pave the ground for an extensive description of the conformational landscape of 15c5 and related cyclic ethers in the near term. J. L. Alonso, F. J. Lorenzo, J. C. López, A. Lesarri, S. Mata and H. Dreizler, Chem. Phys., 218, 267 (1997) S. Blanco, J.C López, J.L. Alonso, P. Ottaviani, W. Caminati, J. Chem. Phys. 119, 880 (2003) S.E. Hill, D. Feller, Int. J. Mass Spectrom. 201, 41 (2000)

Solvent Effects on Cesium Complexation with Crown Ethers from Liquid to Supercritical Fluids

International Nuclear Information System (INIS)

Wai, Chien M.; Rustenholtz, Anne; Wang, Shaofen; Lee, Su-Chen; Herman, Jamie; Porter, Richard A.

2004-01-01

Nuclear magnetic resonance (NMR) techniques were used to study crown ether-water interactions in solvents of low dielectric constants such as chloroform and carbon tetrachloride. Water forms a 1:1 complex with a number of crown ethers including 12-crown-4, 15-crown-5, 18-crown-6, dicyclohexano-18=crown-6, dicyclohexano-24-crown 8, and dibenzl-24-crown-8 in chloroform. Among these crown ethers, the 18-crown-6-H2 complex has the largest equilibrium constant (K=545) and 97% of the crown is complexed to water in chloroform. Addition of carbon tetrachloride to chloroform lowers the equilibrium constants of the crown-water complexes. The partition coefficients of crown ethers (D=crown in water/crown in solvent) between water and organic solvent also vary with solvent composition

Oxime Ethers of (E)-11-Isonitrosostrychnine as Highly Potent Glycine Receptor Antagonists

DEFF Research Database (Denmark)

Mohsen, Amal M Y; Mandour, Yasmine M; Sarukhanyan, Edita

2016-01-01

of the crystal structure of the α3 glycine receptor indicated the same orientation of the strychnine core for all analogues. For the most potent oxime ethers, the ether substituent was accommodated in a lipophilic receptor binding pocket. The findings identify the oxime hydroxy group as a suitable attachment...

Methylation of food commodities during fumigation with methyl bromide

International Nuclear Information System (INIS)

Starratt, A.N.; Bond, E.J.

1990-01-01

Sites of methylation in several commodities (wheat, oatmeal, peanuts, almonds, apples, oranges, maize, alfalfa and potatoes) during fumigation with 14 C-methyl bromide were studied. Differences were observed in levels of the major volatiles: methanol, dimethyl sulphide and methyl mercaptan, products of O- and S-methylation, resulting from treatment of the fumigated materials with 1N sodium hydroxide. In studies of maize and wheat, histidine was the amino acid which underwent the highest level of N-methylation. (author). 24 refs, 3 tabs

Nickel-catalyzed direct synthesis of dialkoxymethane ethers

Indian Academy of Sciences (India)

MURUGAN SUBARAMANIAN

Nickel catalysis; alcohol; paraformaldehyde; ether; solvent-free condition. 1. Introduction ..... oxidation and Dopamine Release with Protective Effects. Against Central ... P, Ghosh A, Saha R and Saha B 2016 A Review on the. Advancement of ...

Effect of benzene, toluene, ethylbenzene, and p-xylene (BTEX) mixture on biodegradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) by pure culture UC1.

Science.gov (United States)

Pruden, Amy; Suidan, Makram

2004-08-01

The effect of a BTEX mixture on the biodegradation of methyl tert-butyl ether (MTBE) and its degradation intermediate, tert-butyl alcohol (TBA) was investigated in the pure bacterial culture UC1, which has been identified to be a strain of the known MTBE-degrader PM1 based on greater than 99% 16S rDNA similarity. Several degradation studies were carried out on UC1 at three initial concentration levels of MTBE or TBA: 6-7; 15-17; and 40-45 mg/l, both with and without BTEX present cumulatively at about half of the MTBE or TBA molar mass in the system. The BTEX mixture was observed not to affect either the rate or the degradation lag period of MTBE or TBA degradation, except that the TBA degradation rate actually increased when BTEX was present initially in the highest concentration studies. When serving as the sole substrate, the MTBE degradation rate ranged from 48 +/- 1.2 to 200 +/- 7.0 mg(MTBE)/g(dw) h, and the TBA degradation rate from 140 +/- 18 to 530 +/- 70 mg(TBA)/g(dw) h. When present with BTEX, MTBE and TBA rates ranged from 46 +/- 2.2 to 210 +/- 14 and 170 +/- 28 to 780 +/- 43 mg(TBA)/g(dw) h, respectively. In studies where varying concentrations of TBA were present with 5 mg/l MTBE, both compounds were degraded simultaneously with no obvious preference for either substrate. In the highest concentration study of TBA with 5 mg/l MTBE, BTEX was also observed to increase the ultimate rate of TBA degradation. In addition to exploring the affect of BTEX, this study also provides general insight into the metabolism of MTBE and TBA by pure culture UC1.

Reproductive Effects of Two Polybrominated Diphenyl Ethers on the Rotifer Brachionus plicatilis.

Science.gov (United States)

Zhang, Jing; Wang, You; Zhou, Bin; Sun, Kai-Ming; Tang, Xuexi

2016-08-01

The effects of two polybrominated diphenyl ethers (PBDEs) on the reproduction of the rotifer Brachionus plicatilis were investigated. Results showed that sexual maturation was promoted by tetra-brominated diphenyl ether-47 (BDE-47) and deca-brominated diphenyl ether-209 (BDE-209), whereas fecundity was inhibited by BDE-47, but promoted by BDE-209. Additionally, both PBDEs affected the expression of two genes, vasa and nanos mRNA, related to rotifer reproduction. This suggests a possible regulatory molecular mechanism at the transcriptional level. Our research extends the current knowledge of the ecotoxicological mechanism induced by PBDEs and provides further essential information for assessing the risks of PBDE contamination in marine ecosystems.

Synthesis and Characterization of Methyl Cellulose/Keratin Hydrolysate Composite Membranes

Directory of Open Access Journals (Sweden)

Bernd M. Liebeck

2017-03-01

Full Text Available It is known that aqueous keratin hydrolysate solutions can be produced from feathers using superheated water as solvent. This method is optimized in this study by varying the time and temperature of the heat treatment in order to obtain a high solute content in the solution. With the dissolved polypeptides, films are produced using methyl cellulose as supporting material. Thereby, novel composite membranes are produced from bio-waste. It is expected that these materials exhibit both protein and polysaccharide properties. The influence of the embedded keratin hydrolysates on the methyl cellulose structure is investigated using Fourier transform infrared spectroscopy (FTIR and wide angle X-ray diffraction (WAXD. Adsorption peaks of both components are present in the spectra of the membranes, while the X-ray analysis shows that the polypeptides are incorporated into the semi-crystalline methyl cellulose structure. This behavior significantly influences the mechanical properties of the composite films as is shown by tensile tests. Since further processing steps, e.g., crosslinking, may involve a heat treatment, thermogravimetric analysis (TGA is applied to obtain information on the thermal stability of the composite materials.

Ether-Directed ortho-C–H Olefination with a PdII/MPAA Catalyst**

Science.gov (United States)

Li, Gang; Leow, Dasheng; Wan, Li; Yu, Jin-Quan

2013-01-01

Weak coordination is powerful! A PdII-catalyzed olefination of ortho-C–H bonds of arenes directed by weakly coordinating ethers is developed using mono-protected amino acid (MPAA) ligands. This finding provides a method for chemically modifying ethers, which are abundant in natural products and drug molecules. PMID:23239120

Methyl Iodide Decomposition at BWR Conditions

International Nuclear Information System (INIS)

Pop, Mike; Bell, Merl

2012-09-01

Based on favourable results from short-term testing of methanol addition to an operating BWR plant, AREVA has performed numerous studies in support of necessary Engineering and Plant Safety Evaluations prior to extended injection of methanol. The current paper presents data from a study intended to provide further understanding of the decomposition of methyl iodide as it affects the assessment of methyl iodide formation with the application of methanol at BWR Plants. This paper describes the results of the decomposition testing under UV-C light at laboratory conditions and its effect on the subject methyl iodide production evaluation. The study as to the formation and decomposition of methyl iodide as it is effected by methanol addition is one phase of a larger AREVA effort to provide a generic plant Safety Evaluation prior to long-term methanol injection to an operating BWR. Other testing phases have investigated the compatibility of methanol with fuel construction materials, plant structural materials, plant consumable materials (i.e. elastomers and coatings), and ion exchange resins. Methyl iodide is known to be very unstable, typically preserved with copper metal or other stabilizing materials when produced and stored. It is even more unstable when exposed to light, heat, radiation, and water. Additionally, it is known that methyl iodide will decompose radiolytically, and that this effect may be simulated using ultra-violet radiation (UV-C) [2]. In the tests described in this paper, the use of a UV-C light source provides activation energy for the formation of methyl iodide. Thus is similar to the effect expected from Cherenkov radiation present in a reactor core after shutdown. Based on the testing described in this paper, it is concluded that injection of methanol at concentrations below 2.5 ppm in BWR applications to mitigate IGSCC of internals is inconsequential to the accident conditions postulated in the FSAR as they are related to methyl iodide formation

Hydrolysis of strained bridgehead bicyclic vinyl ethers and sulfides

International Nuclear Information System (INIS)

Chwang, W.K.; Kresge, A.J.; Wiseman, J.R.

1979-01-01

Rates of hydrolysis of the bridgehead bicyclic vinyl ether 9-oxabicyclo[3.3.1]non-1-ene(6) and its vinyl sulfide counterpart 9-thiabicyclo[3.3.1]non-1-ene(7), catalyzed by the hydronium ion, were measured in H 2 O and in D 2 O solution. These data give isotope effects, k/sub H//k/sub D/ = 2.4 and 1.9 respectively, which show that these reactions occur by the normal, rate-determining carbon protonation, mechanism. The vinyl ether 6 is less reactive than its olefin analogue, bicyclo[3.3.1]non-1-ene (relative rate 1:1/1400), as may have been expected for a constrained bicyclic system such as this, where stabilization of the bridgehead carbocation intermediate by conjugation with oxygen is severely impaired. The vinyl sulfide 7, however, is even less reactive than the vinyl ether (relative rates 1:1/140); this is a remarkable result in view of the fact that conjugation between the sulfur atom and the cationic center is presumably also strongly inhibited. 1 figure, 3 tables

[Visualisation methods for etheric formative forces].

Science.gov (United States)

Burkhard, B; Kittel, R

2009-09-01

Rudolf Steiner, the founder of anthroposophy, suggested the development of visualisation methods for "etheric formative forces". The essential methods, their "spiritual scientific" basis and indications are described and their claims critically tested. The methods are not validated, the key criteria for diagnostic tests (reproducibility, sensitivity, specifity) are not given.

Biosynthesis of ether-phospholipids including plasmalogens, peroxisomes and human disease: new insights into an old problem

NARCIS (Netherlands)

Wanders, Ronald J. A.; Brites, Pedro

2010-01-01

Ether-phospholipids represent an important subclass of phospholipids in animal cell membranes characterized by the presence of an ether bond at the sn-I position and the enrichment of PUFAs at the sn-2 position. Of the different ether-phospholipids, plasmalogens are the most abundant form and their

Some Biological studies on the Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann) After Egg Exposure to Acetone, Diethyl Ether, Ethyl Alcohol and Pupal Gamma Irradiation

International Nuclear Information System (INIS)

Fadel, A.M.

2000-01-01

Some biological studies of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) were carried out to help in controlling this pest. Three laboratory experiments were done to study the effect of acetone, diethyl ether and ethyl alcohol separately or combined with gamma radiation through egg treatment or larval diet treatment. The gamma dose (90 Gy) was applied only on the produced pupae after egg or larval diet treatment. Concentrations of 0, 25, 50 and 100% of each chemical were applied for treating eggs to evaluate egg hatch, pupation, adult emergence and sex ratio. larval diet treatment was done by adding 20 ml of each chemical concentration to 500 gm of larval diet.Treating eggs with ethyl alcohol separately increased pupation significantly at all concentration used while adult emergence was insignificantly increased with the lowest concentration only (25%). Treating larval diet with ethyl alcohol alone increased pupation insignificantly and adult emergence was insignificantly decreased at different concentrations. Moreover, treating eggs or larval diet with diethyl ether alone significantly increased sex ratio at 50% and 2% concentration, respectively,while differed insignificantly by applying different chemicals either on eggs or on larval diet. Treating eggs with the three chemicals before gamma irradiation of the produced pupae fluctuated egg hatch insignificantly compared to gamma irradiation alone. By applying diethyl ether on eggs or acetone in the larval diet decreased egg hatch insignificantly. Competitiveness values were insignificantly increased by applying ethyl alcohol on eggs, acetone or ethyl alcohol on eggs, acetone or ethyl alcohol in larval diet before gamma irradiation of the produced pupae. Survivals of the produced adults, treated as eggs or in the larval diet with different chemicals and irradiated as pupae, fluctuated insignificantly

The surface modifications of multi-walled carbon nanotubes for multi-walled carbon nanotube/poly(ether ether ketone) composites

International Nuclear Information System (INIS)

Cao, Zongshuang; Qiu, Li; Yang, Yongzhen; Chen, Yongkang; Liu, Xuguang

2015-01-01

Graphical abstract: Multi-walled carbon nanotube/poly(ether ether ketone) (MWCNT/PEEK) composites incorporating surface modified multi-walled carbon nanotubes (MWCNTs) as fillers were fabricated in a solution blending method in order to explore the dynamic mechanical and tribological properties of MWCNT/PEEK composites systematically. It is evident that surface modifications of MWCNTs have a significant impact on dispersibility of MWCNTs in PEEK, dynamic mechanical and tribological properties of MWCNT/PEEK composites. Typically, a clear effect of surface modifications of MWCNTs on tribological properties of MWCNT/PEEK composites was observed. A significant reduction in frictional coefficient of MWCNT/PEEK composites with the MWCNTs modified with ethanolamine has been achieved and the self-lubricating film on their worn surfaces was also observed. - Highlights: • The dispersibility of surface modified MWCNTs in PEEK has been studied. • MWCNTs modified with ethanolamine have showed a good dispersion in PEEK. • Surface modifications of MWCNTs have a significant impact on both dynamic mechanical and tribological properties of MWCNT/PEEK composites. - Abstract: The effects of surface modifications of multi-walled carbon nanotubes (MWCNTs) on the morphology, dynamic mechanical and tribological properties of multi-walled carbon nanotube/poly(ether ether ketone) (MWCNT/PEEK) composites have been investigated. MWCNTs were treated with mixed acids to obtain acid-functionalized MWCNTs. Then the acid-functionalized MWCNTs were modified with ethanolamine (named e-MWCNTs). The MWCNT/PEEK composites were prepared by a solution-blending method. A more homogeneous distribution of e-MWCNTs within the composites was found with scanning electron microscopy. Dynamic mechanical analysis demonstrated a clear increase in the storage modulus of e-MWCNT/PEEK composites because of the improved interfacial adhesion strength between e-MWCNTs and PEEK. Furthermore, the presence of e

The surface modifications of multi-walled carbon nanotubes for multi-walled carbon nanotube/poly(ether ether ketone) composites

Energy Technology Data Exchange (ETDEWEB)

Cao, Zongshuang [Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); Research Center of Advanced Material Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Qiu, Li [Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Yang, Yongzhen, E-mail: yyztyut@126.com [Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); Research Center of Advanced Material Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Chen, Yongkang, E-mail: y.k.chen@herts.ac.uk [Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); University of Hertfordshire, School of Engineering and Technology, Hatfield, Hertfordshire AL10 9AB (United Kingdom); Liu, Xuguang [Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

2015-10-30

Graphical abstract: Multi-walled carbon nanotube/poly(ether ether ketone) (MWCNT/PEEK) composites incorporating surface modified multi-walled carbon nanotubes (MWCNTs) as fillers were fabricated in a solution blending method in order to explore the dynamic mechanical and tribological properties of MWCNT/PEEK composites systematically. It is evident that surface modifications of MWCNTs have a significant impact on dispersibility of MWCNTs in PEEK, dynamic mechanical and tribological properties of MWCNT/PEEK composites. Typically, a clear effect of surface modifications of MWCNTs on tribological properties of MWCNT/PEEK composites was observed. A significant reduction in frictional coefficient of MWCNT/PEEK composites with the MWCNTs modified with ethanolamine has been achieved and the self-lubricating film on their worn surfaces was also observed. - Highlights: • The dispersibility of surface modified MWCNTs in PEEK has been studied. • MWCNTs modified with ethanolamine have showed a good dispersion in PEEK. • Surface modifications of MWCNTs have a significant impact on both dynamic mechanical and tribological properties of MWCNT/PEEK composites. - Abstract: The effects of surface modifications of multi-walled carbon nanotubes (MWCNTs) on the morphology, dynamic mechanical and tribological properties of multi-walled carbon nanotube/poly(ether ether ketone) (MWCNT/PEEK) composites have been investigated. MWCNTs were treated with mixed acids to obtain acid-functionalized MWCNTs. Then the acid-functionalized MWCNTs were modified with ethanolamine (named e-MWCNTs). The MWCNT/PEEK composites were prepared by a solution-blending method. A more homogeneous distribution of e-MWCNTs within the composites was found with scanning electron microscopy. Dynamic mechanical analysis demonstrated a clear increase in the storage modulus of e-MWCNT/PEEK composites because of the improved interfacial adhesion strength between e-MWCNTs and PEEK. Furthermore, the presence of e

Use of California biomass in the production of transportation-fuel oxygenates: Estimates for reduction in CO2 emissions and greenhouse gas potential on a life cycle basis

International Nuclear Information System (INIS)

Kadam, K. L.; Camobreco, V. J.; Glazebrook, B. E.

1999-01-01

A set of environmental flows associated with two disposal options for thee types of California biomass - forest biomass, rice straw, chaparral - over their life cycles were studied, the emphasis being on energy consumption and greenhouse gas emissions. The two options studied were: producing ethyl-tertiary-butyl ether (ETBE) from biomass and biomass burning, and producing methyl-tertiary-butyl ether (MTBE) from natural gas. Results showed a lower (by 40 to 50 per cent) greenhouse effect impact, lower net values for carbon dioxide and fossil fuel energy consumption, and higher net values for renewable energy consumption for the ETBE option. Based on these results, the deployment of the biomass-to-ethanol ETBE option is recommended as the one that contributes most to the reduction of GHG emissions. 12 refs., 2 tabs., 5 figs

Physiologically based pharmacokinetic rat model for methyl tertiary-butyl ether; comparison of selected dose metrics following various MTBE exposure scenarios used for toxicity and carcinogenicity evaluation

International Nuclear Information System (INIS)

Borghoff, Susan J.; Parkinson, Horace; Leavens, Teresa L.

2010-01-01

There are a number of cancer and toxicity studies that have been carried out to assess hazard from methyl tertiary-butyl ether (MTBE) exposure via inhalation and oral administration. MTBE has been detected in surface as well as ground water supplies which emphasized the need to assess the risk from exposure via drinking water contamination. This model can now be used to evaluate route-to-route extrapolation issues concerning MTBE exposures but also as a means of comparing potential dose metrics that may provide insight to differences in biological responses observed in rats following different routes of MTBE exposure. Recently an updated rat physiologically based pharmacokinetic (PBPK) model was published that relied on a description of MTBE and its metabolite tertiary-butyl alcohol (TBA) binding to α2u-globulin, a male rat-specific protein. This model was used to predict concentrations of MTBE and TBA in the kidney, a target tissue in the male rat. The objective of this study was to use this model to evaluate the dosimetry of MTBE and TBA in rats following different exposure scenarios, used to evaluate the toxicity and carcinogenicity of MTBE, and compare various dose metrics under these different conditions. Model simulations suggested that although inhalation and drinking water exposures show a similar pattern of MTBE and TBA exposure in the blood and kidney (i.e. concentration-time profiles), the total blood and kidney levels following exposure of MTBE to 7.5 mg/ml MTBE in the drinking water for 90 days is in the same range as administration of an oral dose of 1000 mg/kg MTBE. Evaluation of the dose metrics also supports that a high oral bolus dose (i.e. 1000 mg/kg MTBE) results in a greater percentage of the dose exhaled as MTBE with a lower percent metabolized to TBA as compared to dose of MTBE that is delivered over a longer period of time as in the case of drinking water.

Glycerol tertiary butyl ethers via etherification of glycerol with isobutene

Energy Technology Data Exchange (ETDEWEB)

Behr, A. [Dortmund Univ. (Germany). Chair of Chemical Process Development/Technical Chemistry A

2007-07-01

Glycerol and isobutene can react to a mixture of glycerol tertiary butyl ethers (GTBE) which can be used as additives for gasoline, diesel or biodiesel. This reaction was investigated in lab scale yielding a proposal for a process flow diagram containing reaction, extraction, flash and rectification units. This process has the advantages that only the suitable higher ethers are formed and that both glycerol and isobutene are fully converted. The homogeneous acid catalyst is low-priced and can be completely recycled. (orig.)

Biofilm behavior on sulfonated poly(ether-ether-ketone) (sPEEK)

Energy Technology Data Exchange (ETDEWEB)

Montero, Juan F.D. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-900 (Brazil); Tajiri, Henrique A.; Barra, Guilherme M.O.; Fredel, Márcio C. [Department of Mechanical Engineering (EMC), Federal University of Santa Catarina (UFSC), Florianópolis, SC 88040-900 (Brazil); Benfatti, Cesar A.M.; Magini, Ricardo S. [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-900 (Brazil); Pimenta, Andréa L. [Integrated Laboratories Technologies (InteLAB), Dept. Chemical Engineering (EQA), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-970 (Brazil); Department of Biologie, Université de Cergy Pontoise, 2, Av. Adolphe Chauvin, 95302 Cergy Pontoise (France); Souza, Júlio C.M., E-mail: julio.c.m.souza@ufsc.br [Center for Research on Dental Implants (CEPID), School of Dentistry (ODT), Federal University of Santa Catarina - UFSC, Florianópolis, SC 88040-900 (Brazil); Center for Microelectromechanical Systems (CMEMS), Dept. Mechanical Engineering (DEM), Campus Azurém, 4800-058 Guimarães (Portugal)

2017-01-01

Poly(ether-ether-ketone) (PEEK) has also shown to be very attractive for incorporating therapeutic compounds thanks to a sulfonation process which modifies the material structure resulting in a sulfonated-PEEK (sPEEK). Concerning biomedical applications, the objective of this work was to evaluate the influence of different sulfonation degree of sPEEK on the biofilm growth. PEEK samples were functionalized by using sulphuric acid (98%) and then dissolved into dimethyl-sulfoxide. A dip coating technique was used to synthesize sPEEK thin films. The sulfonation degree of the materials was analyzed by FT-IR, H NMR, TG and IEC. The surfaces were characterized by scanning electron microscopy, profilometry and contact angle analyses. Subsequently, the biofilm formation on sulfonated-PEEK based on Streptococcus mutans and Enterococcus faecalis was measured by spectrophotometry, colony forming units (CFU mL{sup −1}) and SEM. Results obtained from thermal and chemical analyses showed an intensification in sulfonation degree for sPEEK at 2 and 2.5 h. The E. faecalis or S. mutans biofilm growth revealed statistically significant differences (p < 0.05) between 2 and 3 h sulfonation groups. A significant decrease (p < 0.05) in CFU mL{sup −1} was recorded for S. mutans or E. faecalis biofilm grown on 2.5 or 3 h sPEEK. Regarding the thermal-chemical and microbiologic analyses, the sulfonation degree of sPEEK ranging from 2 up to 3 h was successful capable to decrease the biofilm growth. That revealed an alternative strategy to embed anti-biofilm and therapeutic compounds into PEEK avoiding infections in biomedical applications. - Highlights: • PEEK can be dissolved to incorporate therapeutic compounds. • High sulfonation degree on sPEEK affected the biofilm growth. • The sulfonation degree must be controlled to maintain the properties of sPEEK.

Biofilm behavior on sulfonated poly(ether-ether-ketone) (sPEEK)

International Nuclear Information System (INIS)

Montero, Juan F.D.; Tajiri, Henrique A.; Barra, Guilherme M.O.; Fredel, Márcio C.; Benfatti, Cesar A.M.; Magini, Ricardo S.; Pimenta, Andréa L.; Souza, Júlio C.M.

2017-01-01

Poly(ether-ether-ketone) (PEEK) has also shown to be very attractive for incorporating therapeutic compounds thanks to a sulfonation process which modifies the material structure resulting in a sulfonated-PEEK (sPEEK). Concerning biomedical applications, the objective of this work was to evaluate the influence of different sulfonation degree of sPEEK on the biofilm growth. PEEK samples were functionalized by using sulphuric acid (98%) and then dissolved into dimethyl-sulfoxide. A dip coating technique was used to synthesize sPEEK thin films. The sulfonation degree of the materials was analyzed by FT-IR, H NMR, TG and IEC. The surfaces were characterized by scanning electron microscopy, profilometry and contact angle analyses. Subsequently, the biofilm formation on sulfonated-PEEK based on Streptococcus mutans and Enterococcus faecalis was measured by spectrophotometry, colony forming units (CFU mL −1 ) and SEM. Results obtained from thermal and chemical analyses showed an intensification in sulfonation degree for sPEEK at 2 and 2.5 h. The E. faecalis or S. mutans biofilm growth revealed statistically significant differences (p < 0.05) between 2 and 3 h sulfonation groups. A significant decrease (p < 0.05) in CFU mL −1 was recorded for S. mutans or E. faecalis biofilm grown on 2.5 or 3 h sPEEK. Regarding the thermal-chemical and microbiologic analyses, the sulfonation degree of sPEEK ranging from 2 up to 3 h was successful capable to decrease the biofilm growth. That revealed an alternative strategy to embed anti-biofilm and therapeutic compounds into PEEK avoiding infections in biomedical applications. - Highlights: • PEEK can be dissolved to incorporate therapeutic compounds. • High sulfonation degree on sPEEK affected the biofilm growth. • The sulfonation degree must be controlled to maintain the properties of sPEEK.

Radium separation through complexation by aqueous crown ethers and ion exchange or solvent extraction

Energy Technology Data Exchange (ETDEWEB)

Chiarizia, R.; Dietz, M.L.; Horwitz, E.P. [Argonne National Lab., IL (United States). Chemistry Div.; Burnett, W.C. [Florida State Univ., Tallahassee, FL (United States). Dept. of Oceanography

1997-11-01

The effect of three water-soluble, unsubstituted crown ethers (15-crown-5 (15C5), 18-crown-6 (18C6) and 21-crown-7 (21C7)) on the uptake of Ca, Sr, Ba and Ra cations by a sulfonic acid cation exchange resin, and on the extraction of the same cations by xylene solutions of dinonylnaphthalenesulfonic acid (HDNNS) from aqueous hydrochloric acid solutions has been investigated. The crown ethers enhance the sorption of the larger cations by the ion exchange resin, thereby improving the resin selectivity over calcium, a result of a synergistic interaction between the crown ether and the ionic functional groups of the resin. Similarly, the extraction of the larger alkaline earth cations into xylene by HDNNS is strongly synergized by the presence of the crown ethers in the aqueous phase. Promising results for intra-Group IIa cation separations have been obtained using each of the three crown ethers as the aqueous ligands and the sulfonic acid cation exchange resin. Even greater separation factors for the radium-calcium couple have been measured with the crown-ethers and HDNNS solutions in the solvent extraction mode. The application of the uptake and extraction results to the development of radium separation schemes is discussed and a possible flowchart for the determination of {sup 226}Ra/{sup 228}Ra in natural waters is presented.

MethylMix 2.0: an R package for identifying DNA methylation genes.

Science.gov (United States)

Cedoz, Pierre-Louis; Prunello, Marcos; Brennan, Kevin; Gevaert, Olivier

2018-04-14

DNA methylation is an important mechanism regulating gene transcription, and its role in carcinogenesis has been extensively studied. Hyper and hypomethylation of genes is a major mechanism of gene expression deregulation in a wide range of diseases. At the same time, high-throughput DNA methylation assays have been developed generating vast amounts of genome wide DNA methylation measurements. We developed MethylMix, an algorithm implemented in R to identify disease specific hyper and hypomethylated genes. Here we present a new version of MethylMix that automates the construction of DNA-methylation and gene expression datasets from The Cancer Genome Atlas (TCGA). More precisely, MethylMix 2.0 incorporates two major updates: the automated downloading of DNA methylation and gene expression datasets from TCGA and the automated preprocessing of such datasets: value imputation, batch correction and CpG sites clustering within each gene. The resulting datasets can subsequently be analyzed with MethylMix to identify transcriptionally predictive methylation states. We show that the Differential Methylation Values created by MethylMix can be used for cancer subtyping. olivier.gevaert@stanford.edu. https://bioconductor.org/packages/release/bioc/manuals/MethylMix/man/MethylMix.pdf. MethylMix 2.0 was implemented as an R package and is available in bioconductor.

Global DNA methylation analysis using methyl-sensitive amplification polymorphism (MSAP).

Science.gov (United States)

Yaish, Mahmoud W; Peng, Mingsheng; Rothstein, Steven J

2014-01-01

DNA methylation is a crucial epigenetic process which helps control gene transcription activity in eukaryotes. Information regarding the methylation status of a regulatory sequence of a particular gene provides important knowledge of this transcriptional control. DNA methylation can be detected using several methods, including sodium bisulfite sequencing and restriction digestion using methylation-sensitive endonucleases. Methyl-Sensitive Amplification Polymorphism (MSAP) is a technique used to study the global DNA methylation status of an organism and hence to distinguish between two individuals based on the DNA methylation status determined by the differential digestion pattern. Therefore, this technique is a useful method for DNA methylation mapping and positional cloning of differentially methylated genes. In this technique, genomic DNA is first digested with a methylation-sensitive restriction enzyme such as HpaII, and then the DNA fragments are ligated to adaptors in order to facilitate their amplification. Digestion using a methylation-insensitive isoschizomer of HpaII, MspI is used in a parallel digestion reaction as a loading control in the experiment. Subsequently, these fragments are selectively amplified by fluorescently labeled primers. PCR products from different individuals are compared, and once an interesting polymorphic locus is recognized, the desired DNA fragment can be isolated from a denaturing polyacrylamide gel, sequenced and identified based on DNA sequence similarity to other sequences available in the database. We will use analysis of met1, ddm1, and atmbd9 mutants and wild-type plants treated with a cytidine analogue, 5-azaC, or zebularine to demonstrate how to assess the genetic modulation of DNA methylation in Arabidopsis. It should be noted that despite the fact that MSAP is a reliable technique used to fish for polymorphic methylated loci, its power is limited to the restriction recognition sites of the enzymes used in the genomic

Analysis of methanol and its derivatives in illegally produced alcoholic beverages.

Science.gov (United States)

Arslan, M Mustafa; Zeren, Cem; Aydin, Zeki; Akcan, Ramazan; Dokuyucu, Recep; Keten, Alper; Cekin, Necmi

2015-07-01

Illegal alcohol production remains as a common issue worldwide. Methanol poisoning mostly occurs because of the methanol used in production of counterfeit alcohol instead of ethyl alcohol due to its low price or by drinking the liquids containing methyl alcohol. Pectolytic enzymes results in an increase of methanol levels in many fermentation products such as ciders or wines. Methanol poisonings are infrequently encountered in forensic medicine practice. However, sporadic cases due to methanol intoxication as well as epidemic cases have been reported. In this study, we aimed to identify existence of methanol and its metabolites in illegally produced alcoholic beverages used in Antakya region. Twelve legally produced alcohol samples and Fifty-six different illegally produced alcohol samples were collected from the markets and local producers. Existence of methanol, formic acid, methyl amine, methyl formate and trioxan were determined using GC-MS method in these samples. Fifty-six different illegal alcohol samples were analyzed in this study and methanol was detected in 39 (75%) of samples. Formic acid was detected in 3, formamide in 1, methyl amine in 6, methyl formate in 10 and trioxan in 2 samples. Overwhelming majority of illegal alcoholic beverages was detected to contain methanol. Interestingly this study also revealed the presence of trioxane, which has not previously reported among toxic agents in illegal alcohol samples. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

[Ether Day--no laughing matter. The birth of modern anaesthesia].

Science.gov (United States)

Goerig, Michael; Wulf, Hinnerk

2013-10-01

Since centuries the first public demonstration of the anaesthetic properties of ether by William Thomas Green Morton at the Massachusetts General Hospital in Boston on October 16th 1846 is celebrated as "Ether Day" world-wide. The news of the beneficial effects, primarily disposed as a "Yankee Invention", spread over all continents quickly. This was the result of an article, published in the Boston Medical and Surgical Journal on November 18th, 1846. It is mentioning worth that this article was written when Morton had disclosed that the used "preparation", later named as "Nostrum" or "Letheon", was sulphuric ether. The important discovery later became a patent case and was overshadowed by a long lasting priority claim. Nevertheless the readers of the New England Journal of Medicine voted in a survey that this article was the most important publication in the 200 years journals history ever. © Georg Thieme Verlag Stuttgart · New York.

Designing of molecular architecture, synthesis and properties of the next generation of state-of-the-art high-performance thermoplastic fluoro-poly(ether amide)s, (6F-PEA), fluoro-poly(ether amide-imide)s (6F-PEAI), and their co-polymers

International Nuclear Information System (INIS)

Vora, Rohitkumar H.

2010-01-01

Graphical abstract: Molecular architectures of next generation of high-performance advanced heat stable thermoplastic polymer compositions of fluoro-poly(ether amide) (6F-PA) and fluoro-poly(ether amide-imide) (6F-PEAI) having di-ether diamines moieties were designed based on fluoro-polyimide (6F-PI) chemistry, and polymers were synthesized using two novel state-of-the-art 2-(3,4'-carboxy anhydrophenyl-2(4-carboxyphenyl) hexafluoropropane (6FTMA) and 2,2'-bis(4-carboxyphenyl) hexafluropropane (6F-DAc) monomers. Their copolymers: fluoro-copoly(ether amide-(ether imide))s (6F-co(PEA-PEI)), fluoro-copoly(ether amide-(ether amide-imide))s (6F-co(PEA-PEAI)) and fluoro-copoly(ether amide-imide-(ether imide))s (6F-co(PEAI-PEI)) were also designed and synthesized using 2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydrides (6FDA) for the advanced aerospace, defense and industrial engineering applications. -- Abstract: A new generation of high-performance polymers for the advanced industrial, aerospace and defense engineering applications are being investigated in the academic and industrial research institutions throughout the world. Fluoro-polyimides (6F-PI) are one such sub-class of high-performance polyimide polymers. In the last 25 years a number of fluoro-polyimides have been reported but only a handful of them have been commercialized. This paper describes the 6F-polyimide chemistry-based designed molecular architectures and synthesis of two series of next generation of heat stable thermoplastic polymer compositions having di-ether diamines moieties, such as fluoro-poly(ether amide) (6F-PA) and fluoro-poly(ether amide-imide) (6F-PEAI) using the novel state-of-the-art 2-(3,4'-carboxy anhydrophenyl-2(4-carboxyphenyl) hexafluoropropane (6F-TMA) and 2,2'-bis(4-carboxyphenyl) hexafluoropropane (6F-DAc) monomers. Their co-polymers: fluoro-copoly(ether amide-(ether imide))s (6F-co(PEA-PEI)), fluoro-copoly(ether amide-(ether amide-imide))s (6F-co(PEA-PEAI)) and fluoro-copoly(ether