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Sample records for chloromethyl methyl ether

  1. Synthesis and characterization of quaternized poly(phthalazinone ether sulfone ketone) for anion-exchange membrane

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) was prepared from poly(phthalazinone ether sulfone ketone) (PPESK) using chloromethyl octyl ethers (CMOE) with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and chloroform. Quatemized poly(phthalazinone ether sulfone ketone) (QAPPESK) was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance,which was only partly soluble in sulfuric acid (98%) and swollen in N,N-dimethylformamide (DMF). The vanadium redox flow battery (V-RFB) using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.

  2. Solution of a gallstone with methyl-tertiary butyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Brambs, H.J.; Roeren, T.; Holstege, A.; Raedecke, J.

    1987-08-01

    Methyl-t-butyl ether is a new agent to dissolve gallstones. The substance proves to be very successful and acts very rapidly. A percutaneous transhepatic drainage supplies an adequate access route to dissolve calculi within the bile ducts. We report the case of a patient where before insertion of an internal stent a stone in the common bile duct was dissolved within 3 1/2 hours.

  3. Alternariol 9-O-methyl ether

    Directory of Open Access Journals (Sweden)

    Brett A. Neilan

    2012-05-01

    Full Text Available The title compound (AME; systematic name: 3,7-dihydroxy-9-methoxy-1-methyl-6H-benzo[c]chromen-6-one, C15H12O5, was isolated from an endophytic fungi Alternaria sp., from Catharanthus roseus (common name: Madagascar periwinkle. There is an intramolecular O—H...O hydrogen bond in the essentially planar molecule (r.m.s. deviation 0.02 Å. In the crystal, the molecule forms an O—H...O hydrogen bond with its centrosymmetric counterpart with four bridging interactions (two O—H...O and two C—H...O. The almost planar sheets of the dimeric units thus formed are stacked along b axis via C—H...π and π–π contacts [with C...C short contacts between aromatic moieties of 3.324 (3, 3.296 (3 and 3.374 (3 Å].

  4. 4-[(4′-Chloromethyl-[1,1′-biphenyl]-4-yl)methyl]bis(dimethylglyoximato-κ2N,N′)(pyridine-κN)cobalt(III)This article is dedicated to late Professor B. D. Gupta.

    OpenAIRE

    Sarvendra Kumar; Suresh Thapa

    2012-01-01

    The title compound, [Co(C14H14Cl)(C4H6N2O2)2(C5H5N)], is a model compound for the more complex cobalamines like vitamins B12. The CoIII atom is coordinated by a (4′-chloromethyl-[1,1′-biphenyl]-4-yl)methyl group, an N-bonded pyridine and two N,N′-bidentate dimethylglyoximate ligands in a distorted octahedral geometry. The glyoximate ligands exhibit intramolecular O—H...O hydrogen bonds, which is very common in cobaloxime derivatives.

  5. Alternariol 9-methyl ether from the endophytic fungus Alternaria sp. Samif01 and its bioactivities

    Science.gov (United States)

    Lou, Jingfeng; Yu, Ruiting; Wang, Xiaohan; Mao, Ziling; Fu, Linyun; Liu, Yang; Zhou, Ligang

    2016-01-01

    One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75 μg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27 μg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18 μg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17 μg/mL and 74.62 μg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms. PMID:26887231

  6. Customer exposure to MTBE, TAME, C6 alkyl methyl ethers, and benzene during gasoline refueling.

    OpenAIRE

    Vainiotalo, S; Peltonen, Y; Ruonakangas, A; Pfäffli, P

    1999-01-01

    We studied customer exposure during refueling by collecting air samples from customers' breathing zone. The measurements were carried out during 4 days in summer 1996 at two Finnish self-service gasoline stations with "stage I" vapor recovery systems. The 95-RON (research octane number) gasoline contained approximately 2.7% methyl tert-butyl ether (MTBE), approximately 8.5% tert-amyl methyl ether (TAME), approximately 3.2% C6 alkyl methyl ethers (C6 AMEs), and 0.75% benzene. The individual ex...

  7. 75 FR 4288 - Oxirane, 2-Methyl-, Polymer with Oxirane, Dimethyl Ether; Tolerance Exemption

    Science.gov (United States)

    2010-01-27

    ... oxirane, dimethyl ether (CAS Reg. No. 61419-46-3); minimum number average molecular weight (in AMW) 2,800.... * * * * * * * Oxirane, 2-methyl-, polymer with 61419-46-3 oxirane, dimethyl ether, minimum number average molecular... under docket identification (ID) number EPA-HQ-OPP-2009-0675. All documents in the docket are listed...

  8. Searching for Trans Ethyl Methyl Ether in Orion KL

    CERN Document Server

    Tercero, B; 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), $t-CH_3CH_2OCH_3$, 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, $Gt-n-CH_3CH_2CH_2OH$, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30m 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 $\\leq(4.0\\pm0.8)\\times10^{15} cm^{-2}$ and $\\leq(1.0\\pm0.2)\\times10^{15} cm^{-2}$ for tEME and Gt-n-propanol, respectively. The rotational temperature is $\\sim100 K$ for both molecules. We also provide maps of $CH_3OCOH$, $CH_3CH_2OCOH$, $CH_3OCH_3$, $CH_3OH$, a...

  9. Laboratory Method for Analysis of Small Concentrations of Methyl tert-Butyl Ether and Other Ether Gasoline Oxygenates in Water

    Science.gov (United States)

    Rose, Donna L.; Connor, Brooke F.; Abney, Sonja R.; Raese, Jon W.

    1998-01-01

    This Fact Sheet presents data for analysis of nanogram-per-liter concentrations of methyl tert-butyl ether (MTBE) and three other ether gasoline oxygenates, including methyl tert-pentyl ether (TAME), diisopropyl ether (DIPE), and ethyl tert-butyl ether (ETBE), by purge- and-trap capillary-column gas chromatography. Long-term method detection levels (LT-MDLs) for MTBE, TAME, DIPE, and ETBE ranged from 15 to 83 nanograms per liter (0.015 to 0.083 microgram per liter). Nanogram-per-liter-concentration detections are reported if all of the identification criteria are met, whereas previous methods censored detections at a pre-determined method reporting level. The reporting level for this method is defined as two times the LT-MDL, does not censor detections at less than this concentration, and is referred to as the nondetection value (NDV). Bias and variability data from multiple analyses, analysts, and instruments over a 60-day period show the oxygenate recoveries ranging from 100 to 109 percent, with 6 to 8 percent relative standard deviation. MTBE, TAME, DIPE, and ETBE were not detected in the analysis of 225 laboratory reagent blanks from January to December 1997. A preservation study in ground water and surface water indicates that all the oxygenates are stable at pH 2 for up to 216 days, with recoveries ranging from 94 to 115 percent on day 216, and relative standard deviations ranging from 5 to 9 percent for the duration of the study.

  10. APPLICATION OF PHOTOCATALYTIC PROCESS FOR REMOVAL OF METHYL TERT-BUTYL ETHER FROM HIGHLYCONTAMINATED WATER

    Directory of Open Access Journals (Sweden)

    A. Mesdaghinia

    2007-09-01

    Full Text Available The oxygenate methyl tert-butyl ether is added to gasoline to increase the octane level and to reduce carbon monoxide and hydrocarbon emissions by vehicles. The high mobility, water solubility, and resistance to natural attenuation associated with methyl tert-butyl ether may result in contamination of ground and surface waters. In this research the degradation of aqueous methyl tert-butyl ether at relatively high concentrations was investigated by UV-vis/TiO2/H2O2 photocatalytic process. The effect of important operational parameters such as pH, amount of H2O2, catalyst loading, and irradiation time were also studied. Concentrations of methyl tert-butyl ether and intermediates such as tert-butyl formate and tert-butyl alcohol were measured over a 180 min period using a gas chromatograph equipped with flame ionization detector and combined with headspace sampler. Results showed that the time required for complete degradation increased from 30 to 180min, when the initial concentration was increased from 10 to 500mg/L. The first order rate constant for degradation of methyl tert-butyl ether from the hydroxyl radical was estimated to be 0.177 to 0.022 1/min as the concentration increased from 10 to 500mg/L. Study on the overall mineralization monitored by total organic carbon (TOC analysis showed that in the initial concentration of 100mg/L methyl tert-butyl ether, complete mineralization was obtained after 110min under UV-vis/TiO2/H2O2 photocatalytic process.

  11. INFLUENCE OF METHYL TERT-BUTYL ETHER (MTBE) ON LAKE WATER ALGAE

    Science.gov (United States)

    Methyl tert-butyl ether (MTBE) has been used as an octane booster in gasoline in the United States since the 1970s. MTBE use increased greatly in the 1990s with the implementation of the Clean Air Act Amendments of 1990. The MTBE enhanced a more complete combustion of fuel hydroc...

  12. Strobilurin M, tetrachloropyrocatechol and tetrachloropyrocatechol methyl ether: new antibiotics from a Mycena species.

    Science.gov (United States)

    Daferner, M; Anke, T; Hellwig, V; Steglich, W; Sterner, O

    1998-09-01

    The antifungal and cytostatic compound strobilurin M (1) is a new variant of the strobilurins produced by Mycena sp. 96097, a tropical basidiomycete. The same fungus was found to produce tetrachloropyrocatechol (3a) and tetrachloropyrocatechol methyl ether (3b), new natural products, which exhibit antifungal, antibacterial and cytotoxic activities. PMID:9820231

  13. Isothermal (vapor + liquid) equilibria and excess enthalpy data of {1-hexene + methyl butyl ether (MBE)} and {1-hexene + methyl tert-butyl ether (MTBE)} binary systems at several temperatures

    International Nuclear Information System (INIS)

    Highlights: ► Vapor pressures of (1-hexene + methyl butyl ether) or (1-hexene + methyl tert-butyl ether) are reported between (263 and 363) K. ► The two mixtures exhibit positive GE. ► Additionally, molar excess enthalpies, HE, for the two binary systems have been measured at 303.15. - Abstract: The vapor pressures of {1-hexene + methyl butyl ether (MBE)} and {1-hexene + methyl tert-butyl ether (MTBE)} binary mixtures and of the three pure components were measured by means of a static device at temperatures between (263 and 333) K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions were calculated for several constant temperatures and fitted to a third-order Redlich–Kister equation using the Barker’s method. Additionally, molar excess enthalpies, HE, for the two binary systems have been measured at 303.15 K using an isothermal flow calorimeter.

  14. 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

    Several chemical and clinical observations have suggested the presence of at least one more allergen in addition to primin in Primula obconica. The aim of this study was to investigate the allergenicity of the primin precursor miconidin and the related miconidin methyl ether, both isolated from P....... 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 of the...... individual primin reactions, and remained inexplicably negative while testing with miconidin in 96% ethanol and pet., while miconidin methyl ether elicited 7 positive reactions. Although both miconidin and miconidin methyl ether may be allergenic only due to their conversion to primin in the skin, the...

  15. Lewis base activation of Lewis acids. Catalytic enantioselective addition of silyl enol ethers of achiral methyl ketones to aldehydes.

    Science.gov (United States)

    Denmark, Scott E; Heemstra, John R

    2003-06-26

    A highly enantioselective addition of silyl enol ethers derived from simple methyl ketones is described. The catalyst system of silicon tetrachloride activated by a chiral bisphosphoramide (R,R)-7 effectively promotes the addition of a variety of unsubstituted silyl enol ethers to aromatic, olefinic, and heteroaromatic aldehydes in excellent yield. [reaction: see text] PMID:12816434

  16. Determination of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether in human urine by HS-SPME gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are oxygenated compounds added to gasoline to enhance octane rating and to improve combustion. They may be found as pollutants of living and working environments. In this work a robotized method for the quantification of low level MTBE, ETBE and TAME in human urine was developed and validated. The analytes were sampled in the headspace of urine by SPME in the presence of MTBE-d12 as internal standard. Different fibers were compared for their linearity and extraction efficiency: carboxen/polydimethylsiloxane, polydimethylsiloxane/divinylbenzene, and polydimethylsiloxane. The first, although highly efficient, was discarded due to deviation of linearity for competitive displacement, and the polydimethylsiloxane/divinylbenzene fiber was chosen instead. The analysis was performed by GC/MS operating in the electron impact mode. The method is very specific, with range of linearity 30-4600 ng L-1, within- and between-run precision, as coefficient of variation, -1 for all the analytes. The influence of the matrix on the quantification of these ethers was evaluated analysing the specimens of seven traffic policemen exposed to autovehicular emissions: using the calibration curve and the method of standard additions comparable levels of MTBE (68-528 ng L-1), ETBE (-1), and TAME (-1) were obtained

  17. Trans-ethyl methyl ether in space - A new look at a complex molecule in selected hot core regions

    CERN Document Server

    Fuchs, G W; Giesen, T F; Wyrowski, F

    2005-01-01

    An extensive search for the complex molecule trans-ethyl methyl ether towards several hot core regions has been performed. Using the IRAM 30m telescope and the SEST 15m we looked at several frequencies where trans-ethyl methyl ether has strong transitions, as well as lines which are particularly sensitive to the physical conditions in which the molecule can be found. We included G34.26, NGC6334(I), Orion KL, and W51e2 which have previously been proven to have a rich chemistry of complex molecules. Our observations cannot confirm the tentative Orion KL detection made by Charnley et al. (2001) within their stated column density limits, but we confirm the existence of the trans-ethyl methyl ether towards W51e2 with a column density of 2x10^14 cm-2. The dimethyl ether/methanol ratio of 0.6 as well as the newly found ethyl methyl ether/ethanol ratio of 0.13 indicate relative high abundances of ethers toward W51e2. Furthermore, the observation of ethyl methyl ether also confirms the importance of ethanol as a grain...

  18. The Toxicological Assessment of Cyclopentyl Methyl Ether (CPME) as a Green Solvent

    OpenAIRE

    Kiyoshi Watanabe

    2013-01-01

    Cyclopentyl methyl ether (CPME) has been used in chemical synthesis as an alternative to hazardous solvents. According to some earlier investigation by others, CPME has low acute or subchronic toxicity with moderate irritation and negative mutagenicity and negative skin sensitization (Local Lymph Node Assay). Calculated Permitted Daily Exposure (PDE) value of CPME obtained by our 28-day oral toxicity test is 1.5 mg/day, and CPME is thus assumed to be a class 2 equivalent solvent in the ICH (I...

  19. Physical, Thermal, and Spectroscopic Characterization of Biofield Energy Treated Methyl-2-Naphthyl Ether

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Methyl-2-naphthyl ether (MNE) is an organic compound and used as the primary moiety for the synthesis of several antimicrobial and anti-inflammatory agents. This study was attempted to evaluate the impact of biofield energy treatment on the physical, thermal, and spectroscopic properties of MNE. The study was carried out in two groups i.e., control and treated. The treated group was subjected to Mr. Trivedi’s biofield treatment. Afterward, the control and treated samples of MNE were eva...

  20. 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. PMID:25496282

  1. Adsorption of Methyl Tertiary Butyl Ether on Granular Zeolites: Batch and Column Studies

    OpenAIRE

    Abu-Lail, Laila; Bergendahl, John A.; Thompson, Robert W

    2010-01-01

    Methyl tertiary butyl ether (MTBE) has been shown to be readily removed from water with powdered zeolites, but the passage of water through fixed beds of very small powdered zeolites produces high friction losses not encountered in flow through larger sized granular materials. In this study, equilibrium and kinetic adsorption of MTBE onto granular zeolites, a coconut shell granular activated carbon (CS-1240), and a commercial carbon adsorbent (CCA) sample was evaluated. In addition, the effec...

  2. Synthesis of methyl acetate from dimethyl ether using group VIII metal salts of phosphotungstic acid

    Energy Technology Data Exchange (ETDEWEB)

    Sardesai, A.; Lee, S.; Tartamella, T.

    2002-04-01

    Dimethyl ether (DME) can be produced much more efficiently in a single-stage, liquid-phase process from natural gas-based syngas as compared to the conventional process via dehydration of methanol. This process, based on dual catalysts slurried in inert oil, alleviates the chemical equilibrium limitation governing the methanol synthesis reaction and concurrently improves per-pass syngas conversion and reactor productivity. The potential, therefore, for production of methyl acetate via dimethyl ether carbonylation is of industrial importance. In the present study, conversion of dimethyl ether and carbon monoxide to methyl acetate is investigated over a variety of group VIII metal-substituted phosphotungstic acid salts. Experimental results of this catalytic reaction using rhodium, iridium, ruthenium, and palladium catalysts are evaluated and compared in terms of selectivity toward methyl acetate. The effects of active metal, support types, multiple metal loading, and feed conditions on carbonylation activity of DME are examined. Iridium metal substituted phosphotungstic acid supported on Davisil type 643 (pore size 150 A, surface area 279 m{sup 2}/g, mesh size 230-425) silica gel shows the highest activity for DME carbonylation. (author)

  3. Synthesis and Properties of Anion Exchangers Derived from Chloromethyl Styrene Codivinylbenzene and Their Use in Water Treatment

    Directory of Open Access Journals (Sweden)

    Hesham A. Ezzeldin

    2010-01-01

    Full Text Available Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB copolymers is an effective method for preparation of ion-exchange resins. Conventionally, the starting polymer is produced by chloromethylation of a styrene-divinylbenzene copolymer that utilizes chloromethyl methyl ether, a known carcinogen. An alterative approach is to copolymerize vinylbenzyl chloride with divinylbenzene to generate the necessary VBC-DVB. This method provides precise control over the density of the ion-exchange groups. The regiochemistry of the vinylbenzyl chloride methods was realized using solvent-ion exchange groups. In this investigation, an improved solvent system was found for the preparation of anion exchange resins by the vinylbenzyl chloride route. The effectiveness of amination of the intermediate VBC-DVB polymers with a variety of trimethylamine reagents was investigated, and ethanolic trimethylamine produced the highest degree of amination. These resulting ion-exchange polymers were characterized by a variety of techniques such as analytical titrations, nitrogen analysis, Fourier transform infrared spectroscopy and thermal gravimetric analysis. Testing of these copolymers for breakthrough was performed. The results indicate that these anion exchangers have a meaningful increase in thermal stability over commercial anionic exchange beads.

  4. Synthesis and Properties of Anion Exchangers Derived from Chloromethyl Styrene Co divinylbenzene and Their Use in Water Treatment

    International Nuclear Information System (INIS)

    Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB) copolymers is an effective method for preparation of ion-exchange resins. Conventionally, the starting polymer is produced by chloromethylation of a styrene-divinylbenzene copolymer that utilizes chloromethyl methyl ether, a known carcinogen. An alterative approach is to co polymerize vinylbenzyl chloride with divinylbenzene to generate the necessary Vb-Dvb. This method provides precise control over the density of the ion-exchange groups. The regiochemistry of the vinylbenzyl chloride methods was realized using solvent-ion exchange groups. In this investigation, an improved solvent system was found for the preparation of anion exchange resins by the vinylbenzyl chloride route. The effectiveness of amination of the intermediate VBC-DVB polymers with a variety of trimethylamine reagents was investigated, and ethanolic trimethylamine produced the highest degree of amination. These resulting ion-exchange polymers were characterized by a variety of techniques such as analytical titrations, nitrogen analysis, Fourier transform infrared spectroscopy and thermal gravimetric analysis. Testing of these copolymers for breakthrough was performed. The results indicate that these anion exchangers have a meaningful increase in thermal stability over commercial anionic exchange beads

  5. Experimental Analysis and Energetic Evaluation for Mahua Oil Methyl Ester with Diethyl Ether

    Directory of Open Access Journals (Sweden)

    Bhanu Pratap SINGH

    2014-11-01

    Full Text Available A theoretical method based on various existing process models has been developed for the performance evaluation of a compression ignition engine by using diesel and Mahua oil as an input fuel. Experimental evaluations of Mahua oil methyl ester/diesel along with diethyl ether were tested on a single cylinder naturally-aspirated indirect-injection diesel engine. The purpose of using diethyl ether with diesel/biodiesel is to control the emission from the diesel engine and to improve its performance. The effect of test fuels at different volumetric proportion and loads are also analyzed on the engine performance and emission. The comparisons of theoretical and experimental results are discussed. Engine performance characteristics predicted by this model are in closer approximation to that of experimental results. Engineering equation solver has been used to validate the model with the experimental results.

  6. Synthesis and Characterisation of Bis-(chloromethyl Oxetane, its Homopolymer and Copolymer with Tetrahydrofuran

    Directory of Open Access Journals (Sweden)

    T. S. Reddy

    2006-07-01

    Full Text Available Bis-(chloromethyl oxetane (BCMO was synthesised from pentaerythritol by chlorination,followed by ring closure. It was polymerised using BF3-etherate and butanediol system, similarlythe BCMO–THF (tetrahydrofuran copolymer was also synthesised. The monomers and thepolymers were characterised by IR, 1H-NMR and molecular weight. Flame retardant propertiesof the poly-BCMO were also investigated.

  7. Determination of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether in human urine by HS-SPME gas chromatography/mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Scibetta, Licia [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Campo, Laura [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Mercadante, Rosa [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Foa, Vito [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Fustinoni, Silvia [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy)]. E-mail: silvia.fustinoni@unimi.it

    2007-01-02

    Methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are oxygenated compounds added to gasoline to enhance octane rating and to improve combustion. They may be found as pollutants of living and working environments. In this work a robotized method for the quantification of low level MTBE, ETBE and TAME in human urine was developed and validated. The analytes were sampled in the headspace of urine by SPME in the presence of MTBE-d12 as internal standard. Different fibers were compared for their linearity and extraction efficiency: carboxen/polydimethylsiloxane, polydimethylsiloxane/divinylbenzene, and polydimethylsiloxane. The first, although highly efficient, was discarded due to deviation of linearity for competitive displacement, and the polydimethylsiloxane/divinylbenzene fiber was chosen instead. The analysis was performed by GC/MS operating in the electron impact mode. The method is very specific, with range of linearity 30-4600 ng L{sup -1}, within- and between-run precision, as coefficient of variation, <22 and <16%, accuracy within 20% the theoretical level, and limit of detection of 6 ng L{sup -1} for all the analytes. The influence of the matrix on the quantification of these ethers was evaluated analysing the specimens of seven traffic policemen exposed to autovehicular emissions: using the calibration curve and the method of standard additions comparable levels of MTBE (68-528 ng L{sup -1}), ETBE (<6 ng L{sup -1}), and TAME (<6 ng L{sup -1}) were obtained.

  8. New corrosion inhibitor acrylamide methyl ether for mild steel in 1 M HCl

    Science.gov (United States)

    Ma, Xinyu; Jiang, Xiaohui; Xia, Shuwei; Shan, Mingli; Li, Xia; Yu, Liangmin; Tang, Qunwei

    2016-05-01

    Pursuit of good inhibition performance has been a persistent objective for advanced inhibitor industry. Here we demonstrate the experimental realization of a new corrosion inhibitor acrylamide methyl ether (AAME) from N-Methylol acrylamide (N-MAM) for mild steel in 1 M HCl. The resultant adsorption films have inhibition efficiency as high as 96.2%. Moreover, a theoretical investigation is also launched to demonstrate the potential mechanism behind the promising corrosion behaviors. This work represents a significant step forward, as it demonstrates how to make scalable AAME inhibitors as well as to enhance inhibition performances for high-efficiency and cost-effective corrosion inhibition platforms.

  9. Novel oxidative in vitro metabolites of the mycotoxins alternariol and alternariol methyl ether.

    Science.gov (United States)

    Pfeiffer, Erika; Schebb, Nils H; Podlech, Joachim; Metzler, Manfred

    2007-03-01

    The Alternaria toxins alternariol (AOH; 3,7,9-trihydroxy-1-methyl-6H-benzo[c]chromen-6-one) and alternariol methyl ether (AME, 3,7-dihydroxy-9-methoxy-1-methyl-6H-benzo[c]chromen-6-one) are common contaminants of food and feed, but their oxidative metabolism in mammals is as yet unknown. We have therefore incubated AME and AOH with microsomes from rat, human, and porcine liver and analyzed the microsomal metabolites with HPLC and GC-MS/MS. Seven oxidative metabolites of AME and five of AOH were detected. Their chemical structures were derived from their mass spectra using deuterated trimethylsilyl (TMS) derivatives, and from the information obtained from enzymatic methylation. Several of the metabolites were identified by comparison with synthetic reference compounds. AME as well as AOH were monohydroxylated at each of the four possible aromatic carbon atoms and also at the methyl group. In addition, AME was demethylated to AOH and dihydroxylated to a small extent. As the four metabolites arising through aromatic hydroxylation of AME and AOH are either catechols or hydroquinones, the oxidative metabolism of these mycotoxins may be of toxicological significance. PMID:17340575

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

    International Nuclear Information System (INIS)

    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.

  11. CHLOROMETHYLATION OF POLYMERS MADE FROM TECHNICAL DIVINYLBENZENE AND PROPERTY OF THE CHLOROMETHYLATED POLYMERS

    Institute of Scientific and Technical Information of China (English)

    SHI Rongfu; XU Mancai; SHI Zuoqing; WANG Chunhong; FAN Yunge; FENG Junqian; HE Binglin

    2001-01-01

    The goal of this paper was to reveal the feasibility of chloromethylation of polymers made from technical divinylbenzene so as to introduce functional groups into polymeric adsorbents. For this study, the factors that effect the chloromethylation reaction, such as the pore structure of the polymer, the ratio of the reactants to catalyst, the reaction temperature and reaction time and so on were investigated, and the pore structure and property of the chloromethylated polymers were studied The results showed that polymers of technical divinylbenzene could be chloromethylated successfully, and the adsorptive property of the chloromethylated resin was different from that of the initial resin.

  12. Experimental Analysis of Performance of Diesel Engine Using Kusum Methyl Ester With Diethyl Ether as Additive

    Directory of Open Access Journals (Sweden)

    Sandip S. Jawre,

    2014-05-01

    Full Text Available The fossile fuels are widely used in diesel engine and continually depleting with increasing consumption and prices day by day. The fatty acid methyl ester has become an effective alternative to diesel. Various types of vegetable oil such as Jatropha, karanja, cottonseed, neem, sunflower, palm, mahuva, coconut etc. can be used as fuel in diesel engine. Kusum oil is one of the fuel used in present work. The viscosity of kusum oil is very high, so it was reduced by Transesterification process. This study presents effect of diethyl ether as additive to biodiesel of kusum (schliechera oleosa methyl ester on the performance and emission of diesel engine at different load and constant speed and two different injection pressure (170 and 190 bar. From literature it was observed that very few studies had been conducted on use of neat biodiesel and diethyl ether blends and use of kusum methyl ester (KME in diesel engine found to be very less as compared to different biodiesel. Hence this topic was taken under study. The fuels and its blends used are 100% diesel, B100 (100% KME, BD-1 (95% KME, 5% DEE, BD-2 (90% KME, 10% DEE, BD-3 (85% KME, 15% DEE respectively. It was observed that the performance of engine increases at high injection pres-sure. The results indicate that lower BSFC was observed with BD-3 as compared to B100, BD-1 and BD-2. Brake thermal efficiency of BD-3 decreased at 170 bar injection pressure but it increase at 190 bar. Drastic re-duction in smoke is observed with all blends at higher engine loads. DEE addition to biodiesel reflects better engine performance compared to neat biodiesel.

  13. 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...

  14. Estimation of the fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

    2008-01-01

    bed reactor, was determined using a batch kinetic based approach. The procedure involved modeling of methyl tert-butyl ether removal rates from batch experiments followed by parameter estimations. It was estimated to be 5-14% (w/w) of the measured volatile suspended solids concentration in the reactor....

  15. Draft Genome Sequence of Paenibacillus etheri sp. nov. SH7T, a Methyl Tert-Butyl Ether Degrader.

    Science.gov (United States)

    Purswani, Jessica; Guisado, Isabel M; Gonzalez-Lopez, Jesus; Pozo, Clementina

    2016-01-01

    We report here the draft genome sequence of Paenibacillus etheri sp. nov. SH7(T) (= CECT 8558(T) = DSM 29760(T)), isolated from a hydrocarbon-contaminated soil pilot plant in Granada, Spain. The bacterium was isolated and sequenced due to its methyl tert-butyl ether (MTBE)-degrading properties. PMID:26893420

  16. 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,...

  17. Fe-promoted cross coupling of homobenzylic methyl ethers with Grignard reagents via sp3 C-O bond cleavage.

    Science.gov (United States)

    Luo, Shuang; Yu, Da-Gang; Zhu, Ru-Yi; Wang, Xin; Wang, Lei; Shi, Zhang-Jie

    2013-09-14

    The first iron-catalyzed formal cross coupling of homobenzylic methyl ethers with alkyl Grignard reagents is realized. The reaction is proposed to proceed through a sequence of dehydroalkoxylation to form the vinyl-intermediate, followed by Fe-catalyzed selective carbometalation to form a benzylic Grignard reagent. PMID:23884449

  18. CCSD(T) study of the infrared spectrum of ethyl-methyl-ether isotopic varieties

    International Nuclear Information System (INIS)

    Band positions for the infrared bands of various ethyl-methyl-ether isotopomers (CH3CH2OCH2D, CH2DCH2OCH3, CH3CH2OCD3, CD3CH2OCH3, CH3CD2OCH3, CH3CH2O13CH3, 13CH3CH2OCH3, and CH313CH2OCH3) are determined using second order perturbation theory. For species showing G18 symmetry, band position are calculated variationally from a CCSD(T)/cc-pVTZ three-dimensional potential energy surface corrected vibrationally. Potential energy barriers, fundamental frequencies, and rotational constants for excited vibrational levels, are also provided. Calculated frequencies for CH3CH2OCD3 confirm experimental assignments and our predictions for the most abundant isotopomer .

  19. Isolation and Initial Characterization of A Pure Cultures Capable to Degradation Methyl tert- Butyl Ether (MTBE

    Directory of Open Access Journals (Sweden)

    A Nikpey

    2006-07-01

    Full Text Available Methyl tert-butyl ether (MTBE, a gasoline octane enhancer, was introduced as a substitute for lead tetraethyl over 30 years ago. Widespread use of MTBE in gasoline, has introduced MTBE into the environment compartments, mostly into the under ground and surface water and water as a second most frequently detected contaminant. In this study, we have isolated pure cultures from bacterial consortium capable to use MTBE as a sole carbon and energy source. MTBE biodegradation rate was measured in headspace by gas chromatography. Initial liner rates of biodegradation by Pinpoint and white strains were found 2.9 mg and 3 mg MTBE hˉ1 gˉ1 wet biomass, respectively. The results of 16S rDNA PCR disclosed similarities in the banding patterns between the cultures, and the known degrading strain PM1. The results of this study suggest promising perspectives for engineering the in situ bioremediation of MTBE.

  20. Photoinitiated polymerization of new hybrid monomer containing vinyl ether and (methyl) acryloyl groups

    Science.gov (United States)

    Diao, Cuimei; Zou, Yingquan

    2011-04-01

    The photopolymerization kinetics of 4-(vinyloxy)butyl methacrylate containing cationic and free radical polymerizable vinyl groups was studied by real-time Fourier transform infrared spectra (RT-FTIR) .The cationic polymerizable vinyl ether moieties(Vc) of the hybrid monomer in solution polymerized rapidly by exposure to UV light in presence of a cationic photoinitiator such as an iodonium salt or suflonium salt .High conversions, of 90%, were obtained for most of the systems investigated. The efficiency of the cationic photoinitiators in initiating the polymerization of the vinyl ether moieties (Vc) of the hybrid monomer was in the order: suflonium salt > iodonium salt . The free radical polymerizable methacrylate groups (Vr) of the hybrid monomer in solution polymerized by exposure to UV light in presence of a radical photoinitiator such as 2,4,6-trimethyl benzoyl diphenylphoshine oxide (TPO), 2-isopropyl thioxanthone (ITX) , Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (Irgaure 819), 2-Methyl-4'-(methylthio)-2-morpholinopropiophenone (Irgaure 907). Among the photoinitiators , the best effect in initiating the polymerization of methacrylate groups (Vr) of the hybrid monomer is initiator Irgaure 907.

  1. Degradation of aqueous methyl tert-butyl ether by photochemical, biological, and their combined processes

    Directory of Open Access Journals (Sweden)

    Azadeh Asadi

    2006-01-01

    Full Text Available The degradation of aqueous methyl tert-butyl ether (MTBE at relatively high concentrations was investigated by various photo-induced oxidation processes such as UV/H2O2 and UV/TiO2 as well as biological processes and their combination. It was shown that the degradation of MTBE by UV/H2O2 and TiO2 photocatalytic followed a first-order model with apparent rate constant of 1.31×10−1 and 1.21×10−2 min-1, respectively. It was observed that UV/H2O2/TiO2 process did not have any advantages over each of the other processes alone. The biodegradation of methyl tert-butyl ether (MTBE was evaluated using aerobic mixed culture with three different approaches, including ultimate biological oxygen demand (BODU assessment, nonacclimated, and acclimated mixed cultures. The apparent rate constant for the biodegradation of MTBE by nonacclimated mixed culture was 4.36×10−2 day-1. It was shown that the acclimatization of the mixed cultures enhanced the rate of biodegradation of MTBE to 3.24×10−1mg L-1h-1. Finally, the effects of the photocatalytic pretreatment of aqueous MTBE on its subsequent biological treatment were studied. It was observed that the rate of bioreaction was not enhanced and the photocatalytic pretreatment had adverse effects on its biological treatment so that the apparent rate constant decreased to 2.83×10−1 mg L-1h-1.

  2. SYNTHESIS AND CHARACTERIZATION OF A NEW COMBLIKE POLYMER BASED ON POLY (VINYL METHYL ETHER-ALT-MALEIC ANHYDRIDE) BACKBONE

    Institute of Scientific and Technical Information of China (English)

    DING Liming; LIN Yunqing; ZHOU Zinan; NI Jianlong; CHEN Donglin

    1995-01-01

    A new comblike polymer host for polymer electrolyte was synthesized by reacting monomethyl ether of poly(ethylene glycol) with poly(vinyl methyl ether-alt-maleic anhydride) and endcapping the residual carboxylic acid with methanol. Butanone was selected as a solvent for the esterification in order to obtain a completely soluble product. The synthesis process was traced through by IR. Compared with the model compounds, the presumed structure of this comblike polymer has been proved to be valid by 13C NMR. The comb polymer is a white rubbery solid. It can be dissolved in butanone and THF, and manifests good film forming ability.

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

    OpenAIRE

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

    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 phys...

  4. Anaerobic Methyl tert-Butyl Ether-Degrading Microorganisms Identified in Wastewater Treatment Plant Samples by Stable Isotope Probing

    OpenAIRE

    Sun, Weimin; Sun, Xiaoxu; Cupples, Alison M.

    2012-01-01

    Anaerobic methyl tert-butyl ether (MTBE) degradation potential was investigated in samples from a range of sources. From these 22 experimental variations, only one source (from wastewater treatment plant samples) exhibited MTBE degradation. These microcosms were methanogenic and were subjected to DNA-based stable isotope probing (SIP) targeted to both bacteria and archaea to identify the putative MTBE degraders. For this purpose, DNA was extracted at two time points, subjected to ultracentrif...

  5. A QSRR Study on the Relative Retention Time of Halogenated Methyl-phenyl Ethers

    Institute of Scientific and Technical Information of China (English)

    XU Hui-Ying; YU Qing-Sen; ZOU Jian-Wei; WANG Yan-Hua; WANG Hong-Qing; CHEN Xue-Song

    2006-01-01

    Halogenated methyl-phenyl ethers (anisoles) are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 halogenated anisoles at the HF/6-31 G* level. A number of statistically based parameters have been obtained. By multiple regression method, linear relationships between the gas-chromatographic relative retention time (RRT) and structural descriptors have been established for the training set of 32 halogenated anisoles. The result showed that the parameters derived from electrostatic potentials (ESPs) together with the molecular volume (Vmc) could be well used to express the quantitative structure-RRT relationships of halogenated anisoles. The best two-variable regression model gives a correlation coefficient of 0.980 and a standard deviation of 0.07, and the leave-one-out cross-validated correlation coefficient is 0.975. The goodness of the model has been further validated through exploring the predictive power for the testing set of 10 halogenated anisoles.

  6. 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

    2001-03-15

    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/Lto 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. PMID:11347923

  7. Electrochemical simulation of metabolic reactions of the secondary fungal metabolites alternariol and alternariol methyl ether.

    Science.gov (United States)

    Simon, Hannah; Hoffmann, Grete; Hübner, Florian; Humpf, Hans-Ulrich; Karst, Uwe

    2016-04-01

    Mycotoxins are secondary plant metabolites that have been found to cause severe diseases in humans and livestock. Exposure can take place on a daily basis since mycotoxins can be found not only in food, animal food, and dietary supplements but also in materials used in buildings. For this work, the Alternaria toxins alternariol (AOH) and alternariol methyl ether (AME) are chosen as representatives for this relevant compound class and are investigated regarding their oxidative phase I metabolism using a combination of electrochemical (EC) oxidation and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). This previously established method has been proven to be a valuable tool for the electrochemical simulation of certain phase I metabolic reactions. A comparison of the electrochemically generated products with those formed during microsomal incubation demonstrates the potential of the method for the successful prediction of the main phase I metabolic reactions of mycotoxins. It can thus find use as a supportive method in the elucidation of the metabolic pathways of various mycotoxins. Graphical Abstract On-line set-up used for the electrochemical simulation of metabolism reactions of Alternaria toxins. (a) Electrochemical oxidation is coupled directly to the ESI interface of the MS for the generation of mass voltammograms. (b) Implementation of an HPLC system allows a chromatographic separation of previously generated oxidation products. PMID:26869346

  8. Toxicity of methyl tertiary-butyl ether on human blood lymphocytes.

    Science.gov (United States)

    Salimi, Ahmad; Vaghar-Moussavi, Mehrdad; Seydi, Enayatollah; Pourahmad, Jalal

    2016-05-01

    Methyl tertiary-butyl ether (MTBE) is a synthetic solvent widely used as oxygenate in unleaded gasoline. Few studies have addressed the cellular toxicity of MTBE on some cell lines, and so far, no comprehensive study has been conducted to investigate the probable immunotoxicity of this compound. In this study, the toxicity of MTBE on human blood lymphocytes was evaluated. Blood lymphocytes were isolated from healthy male volunteers' blood, using Ficoll polysaccharide followed by gradient centrifugation. Cell viability, reactive oxygen species (ROS) formation, lipid peroxidation, glutathione levels, and damage to mitochondria and lysosome were determined in blood lymphocytes after 6-h incubation with different concentrations of MTBE (0.1, 0.5, 1, and 2 mM). Our results showed that MTBE, in particular, decreased cell viability, which was associated with significant increase at intracellular ROS level and toxic alterations in mitochondria and lysosomes in human blood lymphocytes. Moreover, it was shown that MTBE strongly provoked lipid peroxidation and also depleted glutathione level at higher concentrations. Interestingly, MTBE exhibited its cytotoxic effects at low concentrations that may resemble to its concentrations in human blood following occupational and environmental exposure. It is therefore concluded that MTBE was capable of inducing oxidative stress and damage to mitochondria and lysosomes in human lymphocytes at concentrations ranging from 5 to 40 μg/L, which may be present in human blood as a result of environmental exposure. PMID:26797945

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

    International Nuclear Information System (INIS)

    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 (1750C, 28 atm). The homogeneous rhodium catalyst has been also effective for the synthesis of acetic anhydride (Ac2O) 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

  10. Studies on the Fluorescence Properties of Chloromethyl Polystyrene Supported Fluorophore

    Institute of Scientific and Technical Information of China (English)

    REN; HongXia

    2001-01-01

    The basic materials used in making photoluminescence materials are all synthesized polymers at present, such as PVC, etc [1]. Red and green LEDs are easy to be prepared, but the blue LED is difficult to be done. In this paper, we used chloromethyl polystyrene as supporter, leading into the known fluorophore by polymer chemical reaction, so as to obtaining blue luminous material.  The PS-CH2Cl supported fluorophore are prepared by PS-CH2Cl and benzidine (B), dimethylbenzidine (MA), 4,4'-diamino-diphenyl ether (DAPE), 4,4'-diamino-diphenyl sulfone (DAPS), respectively. They were characterized by IR and elemental analysis. The stead state fluorescence properties of these supported polymers were investigated.The results were summarized in table 1.  ……

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

    Science.gov (United States)

    Hartle, R

    1993-12-01

    Concerns for atmospheric pollution from auto exhaust have led to the blending of "oxygenates" with motor fuels. The most common oxygenate, methyl tert-butyl ether (MTBE) is currently required within several metropolitan areas (Denver and Phoenix) in the range of 12% of the motor fuel. Amendments to the Clean Air Act may expand this requirement to as many as 44 other areas of the United States in the near future. In consideration of the magnitude of potential uncontrolled exposures from its extensive use and a related concern involving the potential influence of MTBE blending on exposures to other constituents of gasoline (particularly benzene), an evaluation of exposures among service station attendants and operators was undertaken at the request, and in cooperation with, the American Petroleum Institute during the latter part of 1990. For application of the survey results to a broad audience, three categories or types of service stations were identified with regard to MTBE use and exposure potential: a) service stations that do not use MTBE or use it only as an octane enhancer, b) service stations with seasonal requirements to use 12-15% MTBE (the Denver, Colorado, and Phoenix, Arizona, metropolitan areas), and c) service stations equipped with stage II (active) vapor recovery systems (several coastal areas, most notably Southern California). At the two sampled service stations that use only minimal amounts of MTBE (less than 1%), only 1 of 32 personal breathing zone (PBZ) samples from attendants was above the analytical limit of detection, reported at 0.16 ppm. The geometric mean concentration of benzene among this same population (n = 32) was 0.04 ppm.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8020445

  12. Removal of Methyl Tert-Butyl Ether (MTBE from Contaminated Water by Photocatalytic Process

    Directory of Open Access Journals (Sweden)

    A Eslami

    2009-06-01

    Full Text Available "nBackground: Methyl tert-butyl ether (MTBE has been commercially used as an octane enhancer to replace tetraethyl lead in gasoline since 1979. The high mobility, water solubility, and resistance to natural attenuation associated with MTBE may re­sult in contamination of ground and surface waters. In this investigation the degradation of aqueous MTBE at relatively high concentrations was studied by UV-vis/TiO2/O2 photocatalytic process. The effect of important operational parameters such as pH, oxygen flow, catalyst loading, and irradiation time were also studied."nMethods:Concentration of MTBE and intermediates such as tert-butyl formate (TBF and tert-butyl alcohol (TBA were meas­ured using a gas chromatograph equipped with flam ionization detector and combined with headspace sampler."nResults: The time required for complete degradation increased from 15 to 150 min, when the initial concentration was in­creased from 10 to 500 mg/L. The first order rate constant for degradation of MTBE from the hydroxyl radical was esti­mated to be 0.266 to 0.033 min-1 as the concentration increased from 10 to 500 mg/L. Study on the overall mineralization moni­tored by total organic carbon (TOC analysis showed that in the initial concentration of 100 mg/L MTBE, complete min­eralization was obtained after 110 min under UV-vis/TiO2/O2 photocatalytic process."nConclusion: The data presented in this paper clearly indicate that UV/TiO2/O2 advanced oxidation process provides an effi­cient treatment alternative for the remediation of MTBE contaminated water.  

  13. Crown ethers as synergists in the extraction of trivalent lanthanides by 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5

    International Nuclear Information System (INIS)

    Synergistic extraction of trivalent lanthanides such as Nd, Eu and Tm with mixtures of 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5 (HPMTFP) and 18-crown-6 or dibenzo-18-crown-6 or 15-crown-5 or monobenzo-15-crown-5 (CE) in chloroform has been investigated. Lanthanides are found to be extracted as Ln(PMTFP)3 with HPMTFP alone and in the presence of crown ether (CE) as Ln(PMTFP)3 . CE. The equilibrium constants of the above species are found to increase monotonically with decreasing ionic radii of these metal ions. The addition of a crown ether to the metal chelate system not only enhances the extraction efficiency but also improves the selectivities among these trivalent lanthanides. (orig.)

  14. 3-(Imidazolyl methyl)-3-aza-bicyclo[3.1.0]hexan-6-yl)methyl ethers: a novel series of mGluR2 positive allosteric modulators.

    Science.gov (United States)

    Zhang, Lei; Rogers, Bruce N; Duplantier, Allen J; McHardy, Stanley F; Efremov, Ivan; Berke, Helen; Qian, Weimin; Zhang, Andy Q; Maklad, Noha; Candler, John; Doran, Angela C; Lazzaro, John T; Ganong, Alan H

    2008-10-15

    The synthesis and structure-activity relationship (SAR) of a novel series of 3-(imidazolyl methyl)-3-aza-bicyclo[3.1.0]hexan-6-yl)methyl ethers, derived from a high throughput screening (HTS), are described. Subsequent optimization led to identification of potent, metabolically stable and orally available mGluR2 positive allosteric modulators (PAMs). PMID:18812259

  15. Methyl tert-butyl ether (MTBE) in urban and rural precipitation in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Achten, C.; Kolb, A.; Puettmann, W. [J.W. Goethe-Universitaet Frankfurt am Main (Germany). Institut fuer Mineralogie-Umweltanalytik

    2001-07-01

    The use of the oxygenate methyl tert-butyl ether (MTBE) in gasoline has led to detectable concentrations in urban and rural air up to 160ppbV. Results from MTBE measurement in precipitation have not been reported so far. In the present study, 120 samples of precipitation collected at 17 sampling locations all over Germany have been analyzed for their MTBE content. Analysis is performed by a combination of headspace-solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC-MS). A 75{mu}m poly(dimethylsiloxane)/Carboxene fiber and a cryostat is used for SPME. The detection limit is 10ng/l. In precipitation samples, MTBE was detected in wintertimes only with a maximum concentration of 85ng/l. Measurement at Frankfurt/M City from 6 September 2000 to 12 March 2001 provided for 49% of the data concentrations in the range of 30-85ng/1 (n=17). Sampling in winter 2000/2001 at several German cities and rural locations showed that MTBE is more often detectable in urban (86%, n=78) than in rural (18%,n=42) precipitation. By comparing the results with corresponding temperatures and amounts of precipitation it can be concluded that the detection of MTBE in urban precipitation is observed at ambient temperatures lower than about 10-15{sup o}C. Moreover, the first precipitation after a dry period accumulates more MTBE than precipitation during or at the end of a wet period (wash-out effect). Highest concentrations occurred in snow samples. Corresponding mean air equilibrium concentrations of 0.04ppbV (urban samples) and 0.0lppbV (rural samples) are calculated. This is about one magnitude lower than year round and summertime measurements in the US and in Switzerland. Urban runoff (n=12) and corresponding precipitation sampling indicate that urban runoff might be composed of about 20% MTBE that is already transported by air and precipitation, whereas about 80% may be attributed to direct uptake of vehicle emissions and leakage near the road during

  16. [Methyl tert-butyl ether (MTBE) in atmosphere of the Pearl River Delta, China].

    Science.gov (United States)

    Wang, Bo-guang; Shao, Min; Zhang, Yuan-hang; Lü, Wan-Ming; Zhou, Yan

    2007-07-01

    The concentration of methyl tert-butyl ether (MTBE) and its spatio-temporal distribution were researched in atmosphere of the Pearl River Delta (PRD) by sampling with air sampling canisters and analyzing with pre-concentrator and gas chromatograph-mass spectrum instrument. The results showed that 1) MTBE could be prevalently checked in atmosphere of traffic area, industrial area, residential area and commercial area of the PRD, and its range of hourly average concentration in the long-term observation was from 0 - 1.250 microg m(-3), the summer had more serious pollution than the spring, and urban was the central area of high MTBE concentration, and suburban in the downwind was obviously polluted by the urban air. 2) During the enhanced observation in summertime, the diurnal average concentration of Guangzhou urban site was (1.520 +/- 0.370) microg m(-3), which was about 7 times of Huadou site in the downwind of Guangzhou and over 100 times of Conghua site in the background of Guangzhou. In urban, 2 peak values appeared in the period of 10:00 - 12:00 and 16:00 - 18:00 respectively, and the nighttime had the lowest average concentration, but the suburban in the downwind had the peak value in the nighttime. 3) During the enhanced observation in wintertime, the diurnal average concentration of Guangzhou urban site was (0.950 +/- 0.240) microg m(-3), which was 3.6 times of Xinken site in the downwind of Guangzhou. Several peak values appeared on the diurnal variation, the high concentration period of urban was in 18:00 - 22:00, and that of suburban was in 04:00 - 10:00 of the next day. 4) When it was weak sunshine, the concentration of MTBE beside the urban traffic roadside was decreasing with the height increasing, but when it was strong sunshine, it was increasing with the height increasing. So, except the original emission from the automobiles, MTBE still had the secondary pollution sources formed by air photochemical reaction. PMID:17891978

  17. Molecular dynamics simulations of the hydration of poly(vinyl methyl ether):Hydrogen bonds and quasi-hydrogen bonds

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Atomistic detailed hydration structures of poly(vinyl methyl ether)(PVME) have been investigated by molecular dynamics simulations under 300 K at various concentrations. Both radial distribution functions and the distance distributions between donors and acceptors in hydrogen bonds show that the hydrogen bonds between the polymer and water are shorter by 0.005 nm than those between water molecules. The Quasi-hydrogen bonds take only 7.2% of the van der Waals interaction pairs. It was found the hydrogen bonds are not evenly distributed along the polymer chain,and there still exists a significant amount(10%) of ether oxygen atoms that are not hydrogen bonded to water at a concentration as low as 3.3%. This shows that in polymer solutions close contacts occur not only between polymer chains but also between chain segments within the polymer,which leads to inefficient contacts between ether oxygen atoms and water molecules. Variation of the quasi-hydrogen bonds with the concentration is similar to that of hydrogen bonds,but the ratio of the repeat units forming quasi-hydrogen bonds to those forming hydrogen bonds approaches 0.2. A transition was found in the demixing enthalpy at around 30% measured by dynamic testing differential scanning calorimetry(DTDSC) for aqueous solutions of a mono-dispersed low molecular weight PVME,which can be related to the transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27%. The transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27% can be used to explain the demixing enthalpy transition at 30% at a molecular scale. In addition,at the concentration of 86%,each ether oxygen atom bonded with water is assigned 1.56 water molecules on average,and ’free’ water molecules emerge at the concentration of around 54%.

  18. 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 ...

  19. 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)

  20. A stable α-chloroalkyllithium compound -2-lithiumchloromethyl-1-methyl-0-carborane

    International Nuclear Information System (INIS)

    2-Lithiumchloromethyl-1-methyl-0-carborane is obtained by the metallation of 2-chloromethyl-1-methyl-0-carborane with BunLi. Lithiumchloromethyl-0-carborane derivative reacts easily with CO2, PhCHO and H2O to form the corresponding acid, chlorohydrins and initial chloromethyl-1-methyl-2-0-carborane respectively. 2 refs

  1. 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...

  2. 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.; Nielsen, O.J.; Sehested, J.

    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...

  3. Asymmetric Total Synthesis of (+)- and (−)-Clusianone and (+)- and (−)Clusianone Methyl Enol Ether via ACC Alkylation and Evaluation of their Anti-HIV Activity

    OpenAIRE

    Garnsey, Michelle R.; Matous, James A.; Kwiek, Jesse J; Coltart, Don M.

    2011-01-01

    The total asymmetric synthesis of (+)- and (−)-clusianone and (+)- and (−)-clusianone methyl enol ether is reported. Asymmetric induction is achieved through the use of ACC alkylation, providing the key intermediates with an er of 99:1. The four synthetic compounds were evaluated for their anti-HIV activity. Both (+)- and (−)-clusianone displayed significant anti-HIV activity.

  4. Effect of age on toxicokinetics among human volunteers exposed to propylene glycol methyl ether (PGME)

    OpenAIRE

    Hopf Nancy B; Vernez David; Berthet Aurélie; Charrière Nicole; Arnoux Christine; Tomicic Catherine

    2012-01-01

    Aging adults represent the fastest growing population segment in many countries. Physiological and metabolic changes in the aging process may alter how aging adults biologically respond to pollutants. In a controlled human toxicokinetic study (exposure chamber; 12 m³), aging volunteers (n=10; >58 years) were exposed to propylene glycol monomethyl ether (PGME, CAS no. 107-98-2) at 50 ppm for 6 h. The dose-dependent renal excretion of oxidative metabolites, conjugated and free PGME could pot...

  5. Oxoaporphine alkaloids: conversion of lysicamine into liriodendronine and its 2-O-methyl ether, and antifungal activity.

    Science.gov (United States)

    Pabuccuoglu, V; Rozwadowska, M D; Brossi, A; Clark, A; Hufford, C D; George, C; Flippen-Anderson, J L

    1991-01-01

    Pschorr reaction of diazonium salt 7 in aqueous methanolic sulfuric acid afforded, besides lysicamine 2, the orange colored sulfate of oxodibenzopyrrocoline (8). The structure is fully supported by an X-ray analysis of its picrate salt. Selective ether cleavage of lysicamine (2) with 48% HBr afforded a hydrobromide of 9, and free betaine 9 on treatment with pyridine-water. Both compounds methylated on treatment with etherial diazomethane on nitrogen to give the known 2-O,N-dimethylliriodendronine (11). Liriodendronine (10) was obtained from lysicamine (2) on heating with pyridine HBr at 189 degrees C, and treatment with pyridine-water, as a dark violet betaine. Betaine 12 was obtained by heating 11.HCl to 200 degrees C. The quaternary salts of lysicamine, lysicamine methiodide (3) and lysicamine methosulfate (4) were comparable in anticandidal activity to liriodenine (1), but were not as active as liriodenine methiodide (13). PMID:2043039

  6. Solubility of anthracene in binary alkane + methyl tert-butyl ether solvent mixtures at 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    McHale, M.E.R.; Kauppila, A.S.M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1996-09-01

    Experimental solubilities are reported for anthracene dissolved in seven binary mixtures containing methyl tert-butyl ether (also called 2-methoxy-2-methylpropane) with hexane, heptane, octane, cyclohexane, methylcyclohexane, 2,2,4-trimethylpentane, and tert-butylcyclohexane (also called (1,1-dimethylethyl)-cyclohexane) at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the seven systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being on the order of 0.5%.

  7. Pulse radiolysis of poly(vinyl methyl ether) in aqueous solution. Formation and structure of primary radicals

    International Nuclear Information System (INIS)

    The reactivity of a temperature-sensitive polymer poly(vinyl methyl ether) (PVME) towards OH, e-aq, and H atoms in aqueous solution has been investigated by pulse radiolysis. The rate constant for reaction of OH with PVME (1.2 x 105 Da) has been determined as 2.2 x 108 dm3 mol-1 s-1 by competition kinetics at 296 K. Hydrogen atoms are less reactive. The rate constant of the reaction of hydrated electrons with PVME is lower than 1.9 x 107 dm3 mol-1 s-1. Radicals of PVME formed in the reaction with OH have a featureless absorption spectrum with increasing absorption towards shorter wavelengths. Upon OH attack three kinds of radicals are generated: two at different α-positions and one at a β-position with respect to the oxygen atom. The α-radicals rapidly reduce tetranitromethane yielding the stable nitroform anion. From the yield of the latter species it is calculated that ca. 54% of the PVME radicals are formed at α-positions. Results are compared with earlier data on low-molecular-weight ethers and simple water-soluble polymers

  8. Biological Activity of Methyl tert-butyl Ether in Relation to Soil Microorganisms has a Negative Environmental Impact

    Directory of Open Access Journals (Sweden)

    Gholam H.S. Bonjar

    2005-01-01

    Full Text Available Fuel oxygenates are added to gasoline to enhance combustion efficiency of automobiles and reduce air pollution. Methyl tert-butyl ether (MTBE is the most commonly used oxygenate because of its low cost, high-octane level and ease of blending with gasoline. However, due to its water solubility, high mobility and low biodegradability it leaches in soil subsurface at the speed of groundwater. Amending gasoline with MTBE has made a widespread contamination of groundwater, surface waters in coastal environments and at low levels in well water. Although current public concern about MTBE contamination is widely discussed, but its adverse effects on soil micro flora is not yet understood. Soil Streptomycetes are beneficial to soil productivity and are of the major contributors to the biological buffering of soils having antagonistic activity against wide spectrum of pathogenic bacteria and fungi. Streptomyceticidal activity of Methyl tert-butyl ether (MTBE is being reported here. Adverse effect of MTBE against four soil-inhabitant Streptomyces spp. isolates and two plant root-pathogens was investigated. To elucidate antimicrobial activity of MTBE, it was tested against four soil isolates of Streptomyces; a plant bacterial-pathogen, Erwinia carotovora and a plant root fungal-pathogen, Fusarium solani. MTBE did not reveal any growth inhibitory-activity against E. carotovora and F. solani but showed strong inhibitory effect against Streptomyces spp. isolates. The Minimum Inhibitory Concentration (MIC was 1/800 of the original MTBE. Fuel leaks and spills can adversely suppress or eliminate the Streptomyces role in the soil causing alteration in the balance of soil micro flora. This change will lead to domination of microorganisms with adverse biological or ecological effects. Fortunately, major oil companies have decided to phase out MTBE from automobile fuels because of its adverse effect on environment and human health.

  9. Fuel Cross Leak of Direct Di-methyl-ether Fuel Cell

    Science.gov (United States)

    Tsutsumi, Yasuyuki; Nakano, Yasuhiro; Haraguchi, Tadao

    Fuel cross leak through a polymer electrolyte membrane of the direct dimethyl ether fuel cell (DDFC) was investigated and was found to be approximately one-tenth that of the direct methanol fuel cell (DMFC). Three phenomena known to appear in the DMFC were also observed in the DDFC. These were (1) fuel cross leak due to the diffusion which increases with the fuel concentration on an open circuit condition, (2) electro-osmotic cross leak, which increases with the current density and fuel concentration, and (3) decrease of fuel cross leak with the increase of the current density due to fuel consumption at low fuel concentration. The decreased fuel cross leak realized by using Nafion ®117 as a membrane and the low fuel concentration of 11% resulted in an increase of the Farady efficiency of the DDFC of up to 90% at a current density of 80mA/cm2. The CO2 quantity at the anode outlet of the operating DDFC was slightly less than 2 mol per 12 protons, as estimated from an electrochemical reaction on the anode. The CO2 quantity at the cathode outlet was also investigated. The CO2 cross leak increased with current density at every CO2 concentration and the diffusion appeared to be the dominant phenomenon of the CO2 cross leak.

  10. Behaviour of water during temperature-induced phase transition in poly(vinyl methyl ether) aqueous solutions. NMR and optical microscopy study

    Czech Academy of Sciences Publication Activity Database

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

    Istanbul : Department of Chemical Engineering, Yeditepe University, 2009. P.IV.033. [European Colloid and Interface Society Meeting /23./. 06.09.2009-11.09.2009, Antalya ] R&D Projects: GA ČR GA202/09/1281 Institutional research plan: CEZ:AV0Z40500505 Keywords : temperature-induced phase transition * hydration * poly(vinyl methyl ether) aqueous solution * NMR Subject RIV: CD - Macromolecular Chemistry

  11. Asymmetric Total Synthesis of (+)- and (−)-Clusianone and (+)- and (−)Clusianone Methyl Enol Ether via ACC Alkylation and Evaluation of their Anti-HIV Activity

    Science.gov (United States)

    Garnsey, Michelle R.; Matous, James A.; Kwiek, Jesse J.; Coltart, Don M.

    2011-01-01

    The total asymmetric synthesis of (+)- and (−)-clusianone and (+)- and (−)-clusianone methyl enol ether is reported. Asymmetric induction is achieved through the use of ACC alkylation, providing the key intermediates with an er of 99:1. The four synthetic compounds were evaluated for their anti-HIV activity. Both (+)- and (−)-clusianone displayed significant anti-HIV activity. PMID:21414776

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

    OpenAIRE

    Scow, K M; MacKay, Douglas

    2008-01-01

    Methyl tert-butyl ether (MTBE) is a contaminant of concern to groundwater resources due to its persistence in subsurface environments. MTBE appears to be degraded readily in the presence of oxygen but is recalcitrant under the anaerobic conditions prevalent in the subsurface, and can be converted into the more toxic compound tert-butanol (TBA). As ethanol is being promoted as a renewable fuel and a replacement for MTBE in gasoline formulations, its potential impact on the biodegradation of pr...

  13. Comparison of Biostimulation versus Bioaugmentation with Bacterial Strain PM1 for Treatment of Groundwater Contaminated with Methyl Tertiary Butyl Ether (MTBE)

    OpenAIRE

    Smith, Amanda E.; Hristova, Krassimira; Wood, Isaac; Mackay, Doug M.; Lory, Ernie; Lorenzana, Dale; Scow, Kate M.

    2004-01-01

    Widespread contamination of groundwater by methyl tertiary butyl ether (MTBE) has triggered the exploration of different technologies for in situ removal of the pollutant, including biostimulation of naturally occurring microbial communities or bioaugmentation with specific microbial strains known to biodegrade the oxygenate. After laboratory studies revealed that bacterial strain PM1 rapidly and completely biodegraded MTBE in groundwater sediments, the organism was tested in an in situ field...

  14. Controlled human exposure to methyl tertiary butyl ether in gasoline: symptoms, psychophysiologic and neurobehavioral responses of self-reported sensitive persons.

    OpenAIRE

    Fiedler, N; Kelly-McNeil, K; Mohr, S; Lehrer, P.; Opiekun, R E; Lee, C.(Institute of Physics, Academia Sinica, Taipei, Taiwan); Wainman, T; Hamer, R.; Weisel, C.; Edelberg, R; Lioy, P J

    2000-01-01

    The 1990 Clean Air Act mandated oxygenation of gasoline in regions where carbon monoxide standards were not met. To achieve this standard, methyl tertiary butyl ether (MTBE) was increased to 15% by volume during winter months in many locations. Subsequent to the increase of MTBE in gasoline, commuters reported increases in symptoms such as headache, nausea, and eye, nose, and throat irritation. The present study compared 12 individuals selected based on self-report of symptoms (self-reported ...

  15. 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.

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

    OpenAIRE

    Alamdari Reza Fareghi; Zamani Faezeh Ghorbani; Zekri Negar

    2014-01-01

    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.

  17. 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.

  18. The impact of groundwater quality on the removal of methyl tertiary-butyl ether (MTBE) using advanced oxidation technology.

    Science.gov (United States)

    Tawabini, B; Fayad, N; Morsy, M

    2009-01-01

    In this study, the removal of methyl tertiary-butyl ether (MTBE) from contaminated groundwater using advanced oxidation technology was investigated. The UV/H(2)O(2) treatment process was applied to remove MTBE from two Saudi groundwater sources that have different quality characteristics with regard to their contents of inorganic species such as chloride, bromide, sulfates and alkalinity. MTBE was spiked into water samples collected from the two sources to a concentration level of about 250 microg/L. A 500 mL bench-scale forced-liquid circulation photoreactor was used to conduct the experiments. Two different UV lamps were utilized: 15 Watt low pressure (LP) and 150 Watt medium pressure (MP). Results of the study showed that the UV/H(2)O(2) process removed more than 90% of MTBE in 20 minutes when the MP lamp was used at an MTBE/H(2)O(2) molar ratio of 1:200. The results also showed that groundwater sources with higher levels of radical scavengers such as alkalinity, bromide, nitrate and sulfate showed lower rate of MTBE removal. PMID:19844063

  19. Study on Pervaporation Membranes for Removing Methanol from C5 or Methyl Tert—butyl Ether Mixtures

    Institute of Scientific and Technical Information of China (English)

    张林; 陈欢林; 周志军; 钱锦文; 高从Jie; 潘祖仁

    2003-01-01

    Several pervaporation membranes,cellulose acetate(CA),polyvinylbutyral(PVB),poly(MMA-co-AA),MMA-AA-BA,CA/PVB blend and CA/poly(MMA-co-AA)blend,were prepared,and their pervporation proper-ties were evaluated by separation of methanol/C5 or methanol/MTBE(methyl tert-butyl ether),The results shows that the CA composite membrane has a high separation performance (flux Jmethanol=35g.m-2.h-1 and separa-tion factor α>400)for methanol /C5 mixtures ,and the pervaporation characteristics of MMA-AA-BA copolymer membranes changes with the ratio of copolymer,For CA/poly(MMA-co-AA) blend membrane,the pervapora-tion performance is improved in comparison with CA or poly(MMA-co-AA) membrane,From the experiment of CA/PVB blend membranes for methanol/MTBE mixture,it is found that the compatibility of blends may affect the separation features of blend membrane.

  20. 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.

  1. 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

    2016-01-01

    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. PMID:26861375

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

    International Nuclear Information System (INIS)

    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 oC), 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 γ-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.

  3. 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 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

  4. Identification of a Ruminococcaceae Species as the Methyl tert-Butyl Ether (MTBE) Degrading Bacterium in a Methanogenic Consortium.

    Science.gov (United States)

    Liu, Tong; Ahn, Hyeri; Sun, Weimin; McGuinness, Lora R; Kerkhof, Lee J; Häggblom, Max M

    2016-02-01

    The widespread use of methyl tert-butyl ether (MTBE) has caused major contamination of groundwater sources and is a concern due to its taste and odor problems, as well as its toxicity. MTBE can be degraded anaerobically which makes bioremediation of contaminated aquifers a potential solution. Nevertheless, the organisms and mechanisms that are responsible for anaerobic MTBE degradation are still unknown. The aim of our research was to identify the organisms actively degrading MTBE. For this purpose we characterized an anaerobic methanogenic culture enriched with MTBE as the sole carbon source from the New Jersey Arthur Kill intertidal strait sediment. The cultures were analyzed using stable isotope probing (SIP) combined with terminal restriction fragment length polymorphism (T-RFLP), high-throughput sequencing and clone library analysis of bacterial 16S rRNA genes. The sequence data indicated that phylotypes belonging to the Ruminococcaceae in the Firmicutes were predominant in the methanogenic cultures. SIP experiments also showed sequential incorporation of the (13)C labeled MTBE by the bacterial community with a bacterium most closely related to Saccharofermentans acetigenes identified as the bacterium active in O-demethylation of MTBE. Identification of the microorganisms responsible for the activity will help us better understand anaerobic MTBE degradation processes in the field and determine biomarkers for monitoring natural attenuation. PMID:26727046

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

    Energy Technology Data Exchange (ETDEWEB)

    An, Youn-Joo [Department of Environmental Science, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)]. E-mail: anyjoo@konkuk.ac.kr

    2005-03-01

    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.

  6. 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.

  7. Stable isotope determination of ester and ether methyl moieties in plant methoxyl groups.

    Science.gov (United States)

    Greule, Markus; Keppler, Frank

    2011-12-01

    Plant methoxyl groups of lignin and pectin have both distinct stable hydrogen isotope (δ(2)H) and carbon isotope (δ(13)C) values that can be used for studying environmental processes and for investigating the origin and authenticity of biomaterials. Up to now, the reported methods have been applied only to determine isotope values of the bulk plant methoxyl pool. In this work, we have applied several methods to distinguish between stable isotope ratios of methoxyl groups of pectin and the bulk plant methoxyl pool. Our results demonstrate that by applying alkaline hydrolysis to specifically cleave off the ester methyl moiety (pectin-like), we can distinguish δ(2)H and δ(13)C values of the pectin methoxyl pool from the bulk methoxyl pool. No measureable isotope discrimination was observed either during sample preparation or during analytical measurement. Furthermore, using this method, no major isotope difference in either the hydrogen or carbon isotope signature of the methoxyl groups of plant pectin and bulk matter from plant species such as leaves from trees, apples, carrots and potatoes was noted. We show the methanol released during alkaline hydrolysis of plant material and subsequently treated with hydriodic acid to be an excellent procedure to measure specifically and precisely the δ(13)C and δ(2)H isotope values of plant pectin-like methoxyl groups. This method is particularly advantageous when plant matter with a low methoxyl content has to be analysed. PMID:22004278

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

    International Nuclear Information System (INIS)

    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)

  9. The mycotoxins alternariol and alternariol methyl ether negatively affect progesterone synthesis in porcine granulosa cells in vitro.

    Science.gov (United States)

    Tiemann, U; Tomek, W; Schneider, F; Müller, M; Pöhland, R; Vanselow, J

    2009-04-25

    Mycotoxins as contaminants of animal food can impair fertility in farm animals. In the regulation of female fertility the ovarian steroid hormone progesterone (P(4)) plays an important role. In the present study we have investigated the influence of the mycotoxins alternariol (AOH), alternariol mono-methyl ether (AME), and tenuazonic acid (TeA) on cell viability, P(4) synthesis, abundance of the key enzymes of P(4) synthesis, P450 cholesterol side-chain cleavage enzyme (P450SCC) and 3-beta-hydroxysteroid dehydrogenase (3-beta-HSD), and of the corresponding Cyp11a1 and Hsd3b transcripts in cultured pig granulosa cells. Already 0.8 microM, AOH and AME inhibited P(4) secretion and 1.6 microM also significantly reduced cell viability. The abundance of P450scc protein but not of Cyp11a1 or Hsd3b transcripts was already significantly reduced by 0.8 microM AOH and AME. 1.6 microM AOH but not AME significantly reduced the abundance of alpha-tubulin and also clearly affected actin protein concentrations. TeA neither impaired viability nor P(4) secretion. Also mycotoxin extracts isolated from naturally occurring Alternaria strains by HPLC purification inhibited cell viability and P(4) synthesis, however at higher concentrations compared to AOH and AME. In conclusion, AOH and AME, but not TeA specifically inhibited P(4) secretion in cultured porcine granulosa cells. Alternaria toxin contaminated food may therefore affect reproductive performance in pig and other mammalian species. PMID:19429235

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-03-01

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

  11. 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.

  12. The interactions of methyl tert-butyl ether on high silica zeolites: a combined experimental and computational study.

    Science.gov (United States)

    Sacchetto, V; Gatti, G; Paul, G; Braschi, I; Berlier, G; Cossi, M; Marchese, L; Bagatin, R; Bisio, C

    2013-08-28

    In this work, the interactions of methyl tert-butyl ether (MTBE) on different dealuminated high silica zeolites were studied by means of both experimental and computational approaches. Zeolites with different textural and surface features were selected as adsorbents and the effect of their physico-chemical properties (i.e. pore size architecture and type and amount of surface OH sites) on sorption capacity were studied. High silica mordenite (MOR) and Y zeolites (both with a SiO2/Al2O3 ratio of 200) and ZSM-5 solid (SiO2/Al2O3 ratio of 500) were selected as model sorbents. By combining FTIR and SS-NMR (both (1)H and (13)C CPMAS NMR) spectroscopy it was possible to follow accurately the MTBE adsorption process on highly defective MOR characterized by a high concentration of surface SiOH groups. The adsorption process is found to occur in different steps and to involve isolated silanol sites, weakly interacting silanols, and the siloxane network of the zeolite, respectively. H-bonding and van der Waals interactions occurring between the mordenite surface and MTBE molecules were modeled by DFT calculations using a large cluster of the MOR structure where two adjacent side-pockets were fused in a large micropore to simulate a dealumination process leading to silanol groups. This is the locus where MTBE molecules are more strongly bound and stabilized. FTIR spectroscopy and gravimetric measurements allowed determination of the interaction strength and sorption capacities of all three zeolites. In the case of both Y and MOR zeolites, medium-weak H-bonding with isolated silanols (both on internal and external zeolite surfaces) and van der Waals interactions are responsible for MTBE adsorption, whereas ZSM-5, in which a negligible amount of surface silanol species is present, displays a much lower amount of adsorbed MTBE retained mainly through van der Waals interactions with zeolite siloxane network. PMID:23860729

  13. 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

    with acetic acid, esters, ethers and alcohols, and in this case for water-acetic acid the CPA-Huron Vidal (CPA-HV) version of the model is used. For the latter binary mixture, new CPA-HV binary parameter sets are estimated using, among others, data for activity coefficients at infinite dilutions. The...... recommended at the end for modeling ternary or multicomponent mixtures containing acetic acid and water....... 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...

  14. Using physiologically based pharmacokinetic modeling to address nonlinear kinetics and changes in rodent physiology and metabolism due to aging and adaptation in deriving reference values for propylene glycol methyl ether and propylene glycol methyl ether acetate.

    Energy Technology Data Exchange (ETDEWEB)

    Kirman, C R.; Sweeney, Lisa M.; Corley, Rick A.; Gargas, M L.

    2005-04-01

    Reference values, including an oral reference dose (RfD) and an inhalation reference concentration (RfC), were derived for propylene glycol methyl ether (PGME), and an oral RfD was derived for its acetate (PGMEA). These values were based upon transient sedation observed in F344 rats and B6C3F1 mice during a two-year inhalation study. The dose-response relationship for sedation was characterized using internal dose measures as predicted by a physiologically based pharmacokinetic (PBPK) model for PGME and its acetate. PBPK modeling was used to account for changes in rodent physiology and metabolism due to aging and adaptation, based on data collected during weeks 1, 2, 26, 52, and 78 of a chronic inhalation study. The peak concentration of PGME in richly perfused tissues was selected as the most appropriate internal dose measure based upon a consideration of the mode of action for sedation and similarities in tissue partitioning between brain and other richly perfused tissues. Internal doses (peak tissue concentrations of PGME) were designated as either no-observed-adverse-effect levels (NOAELs) or lowest-observed-adverse-effect levels (LOAELs) based upon the presence or absence of sedation at each time-point, species, and sex in the two year study. Distributions of the NOAEL and LOAEL values expressed in terms of internal dose were characterized using an arithmetic mean and standard deviation, with the mean internal NOAEL serving as the basis for the reference values, which was then divided by appropriate uncertainty factors. Where data were permitting, chemical-specific adjustment factors were derived to replace default uncertainty factor values of ten. Nonlinear kinetics are were predicted by the model in all species at PGME concentrations exceeding 100 ppm, which complicates interspecies and low-dose extrapolations. To address this complication, reference values were derived using two approaches which differ with respect to the order in which these extrapolations

  15. 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.

  16. Cometabolism of Methyl tertiary Butyl Ether and Gaseous n-Alkanes by Pseudomonas mendocina KR-1 Grown on C5 to C8 n-Alkanes

    OpenAIRE

    Smith, Christy A.; O'Reilly, Kirk T.; Hyman, Michael R.

    2003-01-01

    Pseudomonas mendocina KR-1 grew well on toluene, n-alkanes (C5 to C8), and 1° alcohols (C2 to C8) but not on other aromatics, gaseous n-alkanes (C1 to C4), isoalkanes (C4 to C6), 2° alcohols (C3 to C8), methyl tertiary butyl ether (MTBE), or tertiary butyl alcohol (TBA). Cells grown under carbon-limited conditions on n-alkanes in the presence of MTBE (42 μmol) oxidized up to 94% of the added MTBE to TBA. Less than 3% of the added MTBE was oxidized to TBA when cells were grown on either 1° alc...

  17. Characterization of the Initial Reactions during the Cometabolic Oxidation of Methyl tert-Butyl Ether by Propane-Grown Mycobacterium vaccae JOB5

    OpenAIRE

    Smith, Christy A.; O'Reilly, Kirk T.; Hyman, Michael R.

    2003-01-01

    The initial reactions in the cometabolic oxidation of the gasoline oxygenate, methyl tert-butyl ether (MTBE), by Mycobacterium vaccae JOB5 have been characterized. Two products, tert-butyl formate (TBF) and tert-butyl alcohol (TBA), rapidly accumulated extracellularly when propane-grown cells were incubated with MTBE. Lower rates of TBF and TBA production from MTBE were also observed with cells grown on 1- or 2-propanol, while neither product was generated from MTBE by cells grown on casein-y...

  18. Determination of methyl tert-butyl ether (MTBE) in Chinese fuels by gas chromatography/mass spectrometry and gas chromatography/flame ionization detector

    Institute of Scientific and Technical Information of China (English)

    LIU Jie-min; CHENG Wei; WEN Mei-juan; JIANG Gui-bin

    2004-01-01

    A method was developed to determine the concentration of methyl tert-butyl ether(MTBE) in gasoline,diesel and heating oil by gas chromatography(GC) with mass spectrometry(GC-MS) or flame ionization detection (FID). The diluted gasoline was directly injected into the GC, and the complete separation of MTBE from co-eluting hydrocarbons was not required. GC/MS or GC/FID method can be used to analyze MTBE in different concentration range and have good consistency.

  19. Excess enthalpy, density, and speed of sound determination for the ternary mixture (methyl tert-butyl ether + 1-butanol + n-hexane)

    Energy Technology Data Exchange (ETDEWEB)

    Mascato, Eva [Departamento de Fisica Aplicada, Facultade de Ciencias, Universidade de Vigo, E-36310 Vigo (Spain); Mariano, Alejandra [Laboratorio de Fisicoquimica, Departamento de Quimica, Facultad de Ingenieria, Universidad Nacional del Comahue, 8300 Neuquen (Argentina); Pineiro, Manuel M. [Departamento de Fisica Aplicada, Facultade de Ciencias, Universidade de Vigo, E-36310 Vigo (Spain)], E-mail: mmpineiro@uvigo.es; Legido, Jose Luis [Departamento de Fisica Aplicada, Facultade de Ciencias, Universidade de Vigo, E-36310 Vigo (Spain); Paz Andrade, M.I. [Departamento de Fisica Aplicada, Facultade de Fisica, Universidade de Santiago de Compostela, E-15706 Santiago de Compostela (Spain)

    2007-09-15

    Density, ({rho}), and speed of sound, (u), from T = 288.15 to T = 308.15 K, and excess molar enthalpies, (h{sup E}) at T = 298.15 K, have been measured over the entire composition range for (methyl tert-butyl ether + 1-butanol + n-hexane). In addition, excess molar volumes, V{sup E}, and excess isentropic compressibility, {kappa}{sub s}{sup E}, were calculated from experimental data. Finally, experimental excess enthalpies results are compared with the estimations obtained by applying the group-contribution models of UNIFAC (in the versions of Dang and Tassios, Larsen et al., Gmehling et al.), and DISQUAC.

  20. 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 ostatní: 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: 2.679, year: 2014

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

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

  2. 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.

  3. Liquid crystal photoalignment material based on chloromethylated polyimide

    International Nuclear Information System (INIS)

    We report a liquid crystal photoalignment material with high photosensitivity and excellent thermal stability. The chloromethylated aromatic polyimide exhibited defect-free homogeneous alignment of liquid crystals upon irradiation of polarized deep ultraviolet (UV) for 50 s. The aligning ability of the film was retained up to 210 deg. C, and the cell containing liquid crystals could be stored at 85 deg. C for more than 14 days without any deterioration. FT-IR and UV-vis spectra confirmed that the alignment was induced by photodecomposition of polyimide, drastically accelerated by the introduction of chloromethyl side group

  4. (Liquid + liquid) and (liquid + solid) equilibrium of aqueous two-phase systems containing poly ethylene glycol di-methyl ether 2000 and di-sodium hydrogen phosphate

    International Nuclear Information System (INIS)

    (Liquid + liquid) equilibrium (LLE) for the {poly ethylene glycol di-methyl ether 2000 (PEGDME2000) + Na2HPO4 + H2O} system have been determined experimentally at T = (298.15, 308.15, 313.15, and 318.15) K. The effects of temperature on the binodals and tie-lines for the investigated aqueous two-phase system (ATPS) have been studied. An empirical non-linear expression developed by Merchuk was used for reproducing the experimental binodal data. In this work, the three fitting parameters of the Merchuk equation were obtained with the temperature dependence expressed in the linear form with (T - T0) K as a variable. Furthermore, the modified local composition segment-based NRTL and Wilson models and also osmotic virial equation were used to describe the LLE data of the studied system. Also, the effects of the type of salt on LLE are discussed. In addition, the effects of end groups of the polymers PEGDME2000 and poly ethylene glycol 2000 on phase forming ability were studied. The complete phase diagram for the poly ethylene {glycol di-methyl ether 2000 (PEGDME2000) + Na2HPO4 + H2O} system has also been determined at T = 298.15 K.

  5. Cross-Linked Hydrogels Formed through Diels-Alder Coupling of Furan- and Maleimide-Modified Poly(methyl vinyl ether-alt-maleic acid).

    Science.gov (United States)

    Stewart, S Alison; Backholm, Matilda; Burke, Nicholas A D; Stöver, Harald D H

    2016-02-23

    The Diels-Alder [4 + 2] cycloaddition between furan- and maleimide-functional polyanions was used to form cross-linked synthetic polymer hydrogels. Poly(methyl vinyl ether-alt-maleic anhydride) was reacted with furfurylamine or N-(2-aminoethyl)maleimide in acetonitrile to form pairs of furan- and maleimide-functionalized poly(methyl vinyl ether-alt-maleic acid)s. Mixtures of these mutually reactive polyanions in water gelled within 15 min to 18 h, depending on degree of functionalization and polymer concentrations. Solution and magic-angle spinning (1)H NMR were used to confirm the formation of the Diels-Alder adduct, to analyze competing hydrolytic side reactions, and demonstrate postgelation functionalization. The effect of the degree of furan and maleimide functionalization, polymer concentration, pH, and calcium ion concentration, on gelation time, gel mechanical properties, and equilibrium swelling, are described. Release of dextran as a model drug was studied using fluorescence spectroscopy, as a function of gel composition and calcium treatment. PMID:26800849

  6. Using physiologically-based pharmacokinetic modeling to address nonlinear kinetics and changes in rodent physiology and metabolism due to aging and adaptation in deriving reference values for propylene glycol methyl ether and propylene glycol methyl ether acetate.

    Science.gov (United States)

    Kirman, C R; Sweeney, L M; Corley, R; Gargas, M L

    2005-04-01

    Reference values, including an oral reference dose (RfD) and an inhalation reference concentration (RfC), were derived for propylene glycol methyl ether (PGME), and an oral RfD was derived for its acetate (PGMEA). These values were based on transient sedation observed in F344 rats and B6C3F1 mice during a two-year inhalation study. The dose-response relationship for sedation was characterized using internal dose measures as predicted by a physiologically-based pharmacokinetic (PBPK) model for PGME and its acetate. PBPK modeling was used to account for changes in rodent physiology and metabolism due to aging and adaptation, based on data collected during Weeks 1, 2, 26, 52, and 78 of a chronic inhalation study. The peak concentration of PGME in richly perfused tissues (i.e., brain) was selected as the most appropriate internal dose measure based on a consideration of the mode of action for sedation and similarities in tissue partitioning between brain and other richly perfused tissues. Internal doses (peak tissue concentrations of PGME) were designated as either no-observed-adverse-effect levels (NOAELs) or lowest-observed-adverse-effect levels (LOAELs) based on the presence or the absence of sedation at each time point, species, and sex in the two-year study. Distributions of the NOAEL and LOAEL values expressed in terms of internal dose were characterized using an arithmetic mean and standard deviation, with the mean internal NOAEL serving as the basis for the reference values, which was then divided by appropriate uncertainty factors. Where data were permitting, chemical-specific adjustment factors were derived to replace default uncertainty factor values of 10. Nonlinear kinetics, which was predicted by the model in all species at PGME concentrations exceeding 100 ppm, complicate interspecies, and low-dose extrapolations. To address this complication, reference values were derived using two approaches that differ with respect to the order in which these

  7. Kinetic study of the OH, NO3 radicals and Cl atom initiated atmospheric photo-oxidation of iso-propenyl methyl ether

    Science.gov (United States)

    Taccone, Raúl Alberto; Moreno, Alberto; Colmenar, Inmaculada; Salgado, Sagrario; Martín, María Pilar; Cabañas, Beatriz

    2016-02-01

    Rate coefficients at room temperature and atmospheric pressure for the reaction of isopropenyl methyl ether (i-PME) (CH2dbnd C(CH3)OCH3), with OH and NO3 radicals and with Cl atoms have been determined in a 50 L Pyrex glass reaction chamber in conjunction with Fourier Transform Infrared absorption spectroscopy (FTIR) as a detection technique. The chamber is equipped with a White-type multiple-reflection mirror system with a total optical path length of ≈200 m. Additional experiments were carried out using evacuable Teflon-coated bags (volume 150 L) and a gas chromatography/mass spectrometry-time of flight (GC-TOF MS) detection system. This is the first kinetic study carried out to date for these reactions. The rate coefficients k (in units of cm3 molecule-1 s-1) obtained are: (1.14 ± 0.10) × 10-10 for the OH reaction, (2.41 ± 0.50) × 10-11, for the NO3 reaction and (7.03 ± 0.67) × 10-10 for the Cl reaction. A mechanism is proposed from the observed reaction products. The atmospheric lifetimes of the studied ether is estimated considering the rate coefficients of the reactions with OH and NO3 radicals and Cl atom. Calculated atmospheric lifetimes reveal that the dominant loss process for i-PME is clearly the night-time reaction with the NO3 radical. The radiative efficiency (RE) is obtained from the infrared spectra of the ether and the global warming potential (GWP) is then estimated. Atmospheric implications of the ether emission are discussed.

  8. Graft copolymer electrolytes for high temperature Li-battery applications, using poly(methyl methacrylate) grafted poly(ethylene glycol)methyl ether methacrylate and lithium bis(trifluoromethanesulfonimide)

    International Nuclear Information System (INIS)

    For successful hybridization of heavy vehicles, high temperature batteries might be the solution. Here, high temperature solid polymer electrolytes (SPE's) based on different ratios of poly(methyl methacrylate) (PMMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA), with LiTFSI salt (at a fixed ether oxygen (EO):Li ratio of 20:1) have been prepared and investigated. The copolymers comprise PMMA backbones with grafted PEGMA side-chains containing 9 EO units. The SPE systems were characterized using Raman spectroscopy, broadband dielectric spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, and electrochemical cycling in prototype cells, with a particular focus on the 83 wt% PEGMA system. The electrolytes have good thermal stabilities and dissociate the LiTFSI salt easily, while at the same time maintaining low glass transition temperatures (Tg’s). Depending on the polymeric structure, ionic conductivities >1 mS cm−1 at 110 °C are detected, thus providing ion transport properties for a broad range of electrochemical applications. Prototype Li|polymer electrolyte|LiFePO4 cells utilizing the SPE at 60 °C showed surprisingly low capacities (<20 mA h g−1 LiFePO4), which could be due to poor electrode/electrolyte contacts

  9. 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.

  10. Metabolic Profiling of the Uncaria Hook Alkaloid Geissoschizine Methyl Ether in Rat and Human Liver Microsomes Using High-Performance Liquid Chromatography with Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Hirotaka Kushida

    2015-01-01

    Full Text Available Geissoschizine methyl ether (GM is an indole alkaloid found in Uncaria hook, which is a galenical constituent of yokukansan, a traditional Japanese medicine. GM has been identified as the active component responsible for anti-aggressive effects. In this study, the metabolic profiling of GM in rat and human liver microsomes was investigated. Thirteen metabolites of GM were elucidated and identified using a high-performance liquid chromatography with tandem mass spectrometry method, and their molecular structures were proposed on the basis of the characteristics of their precursor ions, product ions, and chromatographic retention times. There were no differences in the metabolites between the rat and human liver microsomes. Among the 13 identified metabolites, there were two demethylation metabolites, one dehydrogenation metabolite, three methylation metabolites, three oxidation metabolites, two water-adduct metabolites, one di-demethylation metabolite, and one water-adduct metabolite followed by oxidation. The metabolic pathways of GM were proposed on the basis of this study. This study will be helpful in understanding the metabolic routes of GM and related Uncaria hook alkaloids, and provide useful information on the pharmacokinetics and pharmacodynamics. This is the first report that describes the separation and identification of GM metabolites in rat and human liver microsomes.

  11. Metabolic profiling of the Uncaria hook alkaloid geissoschizine methyl ether in rat and human liver microsomes using high-performance liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Kushida, Hirotaka; Matsumoto, Takashi; Igarashi, Yasushi; Nishimura, Hiroaki; Watanabe, Junko; Maemura, Kazuya; Kase, Yoshio

    2015-01-01

    Geissoschizine methyl ether (GM) is an indole alkaloid found in Uncaria hook, which is a galenical constituent of yokukansan, a traditional Japanese medicine. GM has been identified as the active component responsible for anti-aggressive effects. In this study, the metabolic profiling of GM in rat and human liver microsomes was investigated. Thirteen metabolites of GM were elucidated and identified using a high-performance liquid chromatography with tandem mass spectrometry method, and their molecular structures were proposed on the basis of the characteristics of their precursor ions, product ions, and chromatographic retention times. There were no differences in the metabolites between the rat and human liver microsomes. Among the 13 identified metabolites, there were two demethylation metabolites, one dehydrogenation metabolite, three methylation metabolites, three oxidation metabolites, two water-adduct metabolites, one di-demethylation metabolite, and one water-adduct metabolite followed by oxidation. The metabolic pathways of GM were proposed on the basis of this study. This study will be helpful in understanding the metabolic routes of GM and related Uncaria hook alkaloids, and provide useful information on the pharmacokinetics and pharmacodynamics. This is the first report that describes the separation and identification of GM metabolites in rat and human liver microsomes. PMID:25633336

  12. Volumetric behavior 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 to 328.15) K

    International Nuclear Information System (INIS)

    Highlights: • Excess molar volume determined from experimental density values. • Excess adiabatic compressibility. • Excess isobaric thermal expansivity. • Peng–Robinson equation of state. • ERAS model. - Abstract: Values of the density and speed of sound were measured for the ternary system (methyl tert-butyl ether + methylbenzene + butan-1-ol) within the temperature range (298.15 to 328.15) K at atmospheric pressure by a vibrating-tube densimeter DSA 5000. Two binary sub-systems were studied and published previously while the binary sub-system (methyl tert-butyl ether + butan-1-ol) is a new study in this work. Excess molar volume, adiabatic compressibility, and isobaric thermal expansivity were calculated from the experimental values of density and speed of sound. The excess quantities were correlated using the Redlich–Kister equation. The experimental excess molar volumes were analyzed by means of both the Extended Real Associated Solution (ERAS) model and the Peng–Robinson equation of state. The novelty of this work is the qualitative prediction of ternary excess molar volumes for the system containing auto-associative compound and two compounds that can hetero-associate. The combination of the ERAS model and Peng–Robinson equation of state could help to qualitatively estimate the real behavior of the studied systems because the experimental results lie between these two predictions

  13. Improved synthesis of amino acid and dipeptide chloromethyl esters using bromochloromethane

    OpenAIRE

    Gomes, P; Santos, MI; Trigo, MJ; Castanheiro, R.; Moreira, R.

    2003-01-01

    Peptide chloromethyl esters are important compounds in prodrug synthesis. A simple, mild and efficient method for the synthesis of chloromethyl esters of N-blocked amino acids and dipeptides using exclusively bromochloromethane is reported. These N-blocked amino acid and dipeptide chloromethyl esters react readily with the carboxylic acid group of aspirin and with the sulfonamido group of the antimalarial sulfamethazine, to give the corresponding prodrugs.

  14. Hydrogen bonding in the recovery of phenols and methyl-t-butyl ether : molecular modeling and calorimetry

    OpenAIRE

    Cuypers, R.

    2010-01-01

    The purification of waste water is very important, for clean potable water is a common good and a necessity. Surface water purification is nowadays carried out on a massive industrial scale, and clean water is at our disposal virtually everywhere and always. However, cleaning industrial waste water can be a difficult task. Although apolar and slightly polar compounds can be removed from water relatively easily e.g. by extraction to an apolar phase, more polar pollutants like phenol and methyl...

  15. Cu(II), Zn(II) andMn(II) complexes of poly(methyl vinyl ether-alt-maleic anhydride). Synthesis, characterization and thermodynamic parameters

    Indian Academy of Sciences (India)

    Hidayet Mazi; Ali Gulpinar

    2014-01-01

    The complexes of poly(methyl vinyl ether-alt-maleic anhydride) (poly(MVE-alt-MA)) with Zn(II), Mn(II) and Cu(II) ions were synthesized from the reaction of the aqueous solution of copolymer and metal(II) chlorides at different temperatures ranging from 25° to 40°C. Elemental analysis of themetal-polymer complexes suggests that the metal to ligand ratio is 1:1. The formation constants of each complex were determined by the mol-ratio method. UV-Vis studies showed that the complex formation tendency increased in the following order: Zn(II) > Cu(II) > Mn(II). This order was confirmed by the Irving-William series and Pearson’s classification. The IR spectral data indicated the metal ions to be coordinated through the hydroxyl groups of the hydrolysed maleic anhydride. The intrinsic viscosity and thermal properties of the copolymer and metal-polymer complexes and their thermal stability are discussed.

  16. Interaction of insulin with methyl tert-butyl ether promotes molten globule-like state and production of reactive oxygen species.

    Science.gov (United States)

    Valipour, Masoumeh; Maghami, Parvaneh; Habibi-Rezaei, Mehran; Sadeghpour, Mostafa; Khademian, Mohamad Ali; Mosavi, Khadijeh; Sheibani, Nader; Moosavi-Movahedi, Ali Akbar

    2015-09-01

    Interaction of methyl tert-butyl ether (MTBE) with proteins is a new look at its potential adverse biological effects. When MTBE is released to the environment it enters the blood stream through inhalation, and could affect the properties of various proteins. Here we investigated the interaction of MTBE with insulin and its effect on insulin structural changes. Our results showed that insulin formed a molten globule (MG)-like structure in the presence of 8 μM MTBE under physiological pH. The insulin structural changes were studied using spectroscopy methods, viscosity calculation, dynamic light scattering and differential scanning calorimetry. To delineate the mechanisms involved in MTBE-protein interactions, the formation of reactive oxygen specious (ROS) and formation of protein aggregates were measured. The chemiluminscence experiments revealed an increase in ROS production in the presence of MTBE especially in the MG-like state. These results were further confirmed by the aggregation tests, which indicated more aggregation of insulin at 40 μM MTBE compared with 8 μM. Thus, the formation of initial aggregates and exposure of the hydrophobic patches upon formation of the MG-like state in the presence of MTBE drives protein oxidation and ROS generation. PMID:26193678

  17. In vitro identification of human cytochrome P450 isoforms involved in the metabolism of Geissoschizine methyl ether, an active component of the traditional Japanese medicine Yokukansan.

    Science.gov (United States)

    Matsumoto, Takashi; Kushida, Hirotaka; Maruyama, Takeshi; Nishimura, Hiroaki; Watanabe, Junko; Maemura, Kazuya; Kase, Yoshio

    2016-01-01

    1. Yokukansan (YKS) is a traditional Japanese medicine also called kampo, which has been used to treat neurosis, insomnia, and night crying and peevishness in children. Geissoschizine methyl ether (GM), a major indole alkaloid found in Uncaria hook, has been identified as a major active component of YKS with psychotropic effects. Recently, GM was reported to have a partial agonistic effect on serotonin 5-HT1A receptors. However, there is little published information on GM metabolism in humans, although several studies reported the blood kinetics of GM in rats and humans. In this study, we investigated the GM metabolic pathways and metabolizing enzymes in humans. 2. Using recombinant human cytochrome P450 (CYP) isoforms and polyclonal antibodies to CYP isoforms, we found that GM was metabolized into hydroxylated, dehydrogenated, hydroxylated+dehydrogenated, demethylated and water adduct forms by some CYP isoforms. 3. The relative activity factors in human liver microsomes were calculated to determine the relative contributions of individual CYP isoforms to GM metabolism in human liver microsomes (HLMs). We identified CYP3A4 as the CYP isoform primarily responsible for GM metabolism in human liver microsomes. 4. These findings provide an important basis for understanding the pharmacokinetics and pharmacodynamics of GM and YKS. PMID:26337900

  18. 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.

  19. Combined toxicities of methyl tert-butyl ether and its metabolite tert-butyl alcohol on earthworms via different exposure routes.

    Science.gov (United States)

    Lee, Woo-Mi; Yoon, Youngdae; An, Youn-Joo

    2015-06-01

    Methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) are among the major soil contaminants that threaten the health of soil ecosystems. Many MTBE-contaminated sites accumulate TBA, because TBA is the intermediate of MTBE biodegradation. To access the risk of MTBE and TBA in soil, we investigated the combined toxicities of MTBE and TBA using two earthworm species, Perionyx excavatus and Eisenia andrei, as well as the toxic effects via different exposure routes. The combined toxicity showed weak antagonistic effects (LC50mix values were slightly greater than 1.0), and sensitivity toward same pollutants differed in the two earthworm species. Moreover, the toxicity of MTBE and TBA was also affected by the exposure route; both filter paper and artificial soil tests showed that dermal-only exposure to MTBE had an even greater toxic effect than combined dermal and oral exposure. Thus, we suggest that diverse environmental factors including organic materials, the physicochemical properties of the contact media, and the exposure routes of the organism, should be taken into consideration when assessing the effects of pollutants on organisms in diverse environmental systems. PMID:25706436

  20. Preparation of Poly-(Methyl vinyl ether-co-maleic Anhydride Nanoparticles by Solution-Enhanced Dispersion by Supercritical CO2

    Directory of Open Access Journals (Sweden)

    Yong-Qiang Kang

    2012-10-01

    Full Text Available The supercritical CO2-based technologies have been widely used in the formation of drug and/or polymer particles for biomedical applications. In this study, nanoparticles of poly-(methyl vinyl ether-co-maleic anhydride (PVM/MA were successfully fabricated by a process of solution-enhanced dispersion by supercritical CO2 (SEDS. A 23 factorial experiment was designed to investigate and identify the significance of the processing parameters (concentration, flow and solvent/nonsolvent for the surface morphology, particle size, and particle size distribution of the products. The effect of the concentration of PVM/MA was found to be dominant in the results regarding particle size. Decreasing the initial solution concentration of PVM/MA decreased the particle size significantly. After optimization, the resulting PVM/MA nanoparticles exhibited a good spherical shape, a smooth surface, and a narrow particle size distribution. Fourier transform infrared spectroscopy (FTIR spectra demonstrated that the chemical composition of PVM/MA was not altered during the SEDS process and that the SEDS process was therefore a typical physical process. The absolute value of zeta potential of the obtained PVM/MA nanoparticles was larger than 40 mV, indicating the samples’ stability in aqueous suspension. Analysis of thermogravimetry-differential scanning calorimetry (TG-DSC revealed that the effect of the SEDS process on the thermostability of PVM/MA was negligible. The results of gas chromatography (GC analysis confirmed that the SEDS process could efficiently remove the organic residue.

  1. Methyl ether of 6-oxo-6-[2,2-ethylenedioxy-5- (di methoxycarbonylmethyl)-cyclopent-1-yl]-hexanoic acid as prototype of new generation of radiosensitizers

    International Nuclear Information System (INIS)

    Radiosensitizing activity of analogue of the 11-deoxy-PGE series with malonic or heterocyclic fragments in ω-chain was studied. In experiments with HeLa cell cultures of uterine cervix tumour it was revealed that one of prostanoids - methyl ether of 6-oxo-6-[2,2-ethylenedioxy-5- (di methoxycarbonylmethyl)-cyclopent-1-yl]-hexanoic acid - caused practically significant increase of irradiated tumour cells death, in efficiency one compared well with metronidazole. The roles of 7-oxocarboxyalkylic α-chain and malonic ester fragment in ω-chain in capacity of pharmacophores responsible for increase of tumour cells sensitivity to gamma-irradiation at relatively small doses were detected. It was established that studied prostanoid in concentration 10-6 mole/l led to saturating effect, when it was incubated with HeLa cells for 30 and 60 min before irradiation, this prostanoid increased tumour cell radiodamaging by 32 and 25% after irradiation in dose range between 2 and 4 Gy. It was inferred that obtained prostanoid is a prototype of new radiosensitizing drug

  2. Effects of the ether phospholipid AMG-PC on mast cells are similar to that of the ether lipid AMG but different from that of the analogue hexadecylphosphocholine

    DEFF Research Database (Denmark)

    Grosman, Nina

    Farmakologi, ether phospholipid, hexacylphosphocholine, miltefosine, protein kinase C, AMG-PC(alkyl-methyl-glycero-phosphocholine), Histamine release, mast cell......Farmakologi, ether phospholipid, hexacylphosphocholine, miltefosine, protein kinase C, AMG-PC(alkyl-methyl-glycero-phosphocholine), Histamine release, mast cell...

  3. Evaluating UV/H2O2 processes for methyl tert-butyl ether and tertiary butyl alcohol removal: effect of pretreatment options and light sources.

    Science.gov (United States)

    Li, Ke; Hokanson, David R; Crittenden, John C; Trussell, Rhodes R; Minakata, Daisuke

    2008-12-01

    In this paper, we evaluate the efficiency of UV/H2O2 process to remove methyl tert-butyl ether (MtBE) and tertiary butyl alcohol (tBA) from a drinking water source. Kinetic models were used to evaluate the removal efficiency of the UV/H2O2 technologies with different pretreatment options and light sources. Two commercial UV light sources, i.e. low pressure, high intensity lamps and medium pressure, high intensity lamps, were evaluated. The following pretreatment alternatives were evaluated: (1) ion exchange softening with seawater regeneration (NaIX); (2) Pellet Softening; (3) weak acid ion exchange (WAIX); and (4) high pH lime softening followed by reverse osmosis (RO). The presence or absence of a dealkalization step prior to the UV/H2O2 Advanced Oxidation Process (AOP) was also evaluated for each pretreatment possibility. Pretreatment has a significant impact on the performance of UV/H2O2 process. The NaIX with dealkalization was shown to be the most cost effective. The electrical energy per order (EEO) values for MtBE and tBA using low pressure high output UV lamps (LPUV) and 10mg/LH2O2 are 0.77 and 3.0 kWh/kgal-order, or 0.20 and 0.79 kWh/m3-order, respectively. For medium pressure UV high output lamps (MPUV), EEO values for MtBE and tBA are 4.6 and 15 kWh/kgal-order, or 1.2 and 4.0 kWh/m3-order, for the same H2O2 dosage. PMID:18951605

  4. Composite electrolytes of polyethylene glycol methyl ether and TiO2 for dye-sensitized solar cells-Effect of heat treatment

    International Nuclear Information System (INIS)

    Highlights: → The heat treatment (80 deg. C) on prepared PEGME-TiO2 composite was essential step to improve the morphological and electrochemical properties. → Raman spectra of PEGME-acid, PEGME-TiO2 and PEGME-TiO2/80 deg. C composite electrolytes. → PEGME-TiO2/80 deg. C shows drastically increased strong peak (I3- species) with a slight shifting at 113.1 cm-1. → Indicates the significant increase of I3- species in redox electrolytes upon heat treatment. - Abstract: For solid-state dye-sensitized solar cells (DSSCs), a composite electrolyte of polyethylene glycol methyl ether (PEGME) and titania (TiO2) nanoparticles was prepared and characterized by Fourier transform-infra red (FT-IR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Raman spectroscopy. The heat treatment on PEGME and TiO2 composite was found to be an essential step to improve morphology, amorphicity and ionic conductivity of PEGME-TiO2 composite electrolytes. It was attributed to the increased bond strength of OC-O-Ti between PEGME and TiO2 and increased surface roughness of composite materials, which may help to absorb a large amount of iodide couple and effective generation of I3- ions. A DSSC fabricated with heat treated PEGME-TiO2 composite electrolyte showed significantly enhanced overall conversion efficiency of 3.1%, which was 20% higher than that of the DSSC fabricated with bare PEGME-TiO2 composite electrolyte.

  5. 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

    2015-08-01

    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.

  6. Externally reformed solid oxide fuel cell-micro-gas turbine (SOFC-MGT) hybrid systems fueled by methanol and di-methyl-ether (DME)

    Energy Technology Data Exchange (ETDEWEB)

    Cocco, D.; Tola, V. [Department of Mechanical Engineering, University of Cagliari, Piazza d' Armi, 09123 Cagliari (Italy)

    2009-12-15

    Solid oxide fuel cell-micro-gas turbine (SOFC-MGT) hybrid power plants integrate a solid oxide fuel cell and a micro-gas turbine and can achieve efficiencies of over 60% even for small power outputs (200-500 kW). The SOFC-MGT systems currently developed are fueled with natural gas, which is reformed inside the same stack, but the use of alternative fuels can be an interesting option. In particular, as the reforming temperature of methanol and di-methyl-ether (DME) (200-350 C) is significantly lower than that of natural gas (700-900 C), the reformer can be sited outside the stack. External reforming in SOFC-MGT plants fueled by methanol and DME enhances efficiency due to improved exhaust heat recovery and higher voltage produced by the greater hydrogen partial pressure at the anode inlet. The study carried out in this paper shows that the main operating parameters of the fuel reforming section (temperature and steam-to-carbon ratio (SCR)) must be carefully chosen to optimise the hybrid plant performance. For the stoichiometric SCR values, the optimum reforming temperature for the methanol fueled hybrid plant is approximately 240 C, giving efficiencies of about 67-68% with a SOFC temperature of 900 C (the efficiency is about 72-73% at 1000 C). Similarly, for DME the optimum reforming temperature is approximately 280 C with efficiencies of 65% at 900 C (69% at 1000 C). Higher SCRs impair stack performance. As too small SCRs can lead to carbon formation, practical SCR values are around one for methanol and 1.5-2 for DME. (author)

  7. 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)

    Using energy systems analysis, we examine the potential to reduce CO2 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 CO2 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 CO2 emissions or oil use can, however, be achieved if biomass replaces coal or oil in stationary applications. -- Highlights: ► CO2 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.

  8. 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.

  9. Geissoschizine methyl ether, an alkaloid from the Uncaria hook, improves remyelination after cuprizone-induced demyelination in medial prefrontal cortex of adult mice.

    Science.gov (United States)

    Morita, Shoko; Tatsumi, Kouko; Makinodan, Manabu; Okuda, Hiroaki; Kishimoto, Toshifumi; Wanaka, Akio

    2014-01-01

    Accumulating evidence indicates that the medial prefrontal cortex (mPFC) is a site of myelin and oligodendrocyte abnormalities that contribute to psychotic symptoms of schizophrenia. The development of therapeutic approaches to enhance remyelination, a regenerative process in which new myelin sheaths are formed on demyelinated axons, may be an attractive remedial strategy. Geissoschizine methyl ether (GM) in the Uncaria hook, a galenical constituent of the traditional Japanese medicine yokukansan (Yi-gan san), is one of the active components responsible for the psychotropic effects of yokukansan, though little is known about the mechanisms underlying the effects of either that medicine or GM itself. In the present study, we employed a cuprizone (CPZ)-induced demyelination model and examined the cellular changes in response to GM administration during the remyelination phase in the mPFC of adult mice. Using the mitotic marker 5-bromo-2'-deoxyuridine (BrdU), we demonstrated that CPZ treatment significantly increased the number of BrdU-positive NG2 cells, as well as microglia and mature oligodendrocytes in the mPFC. Newly formed oligodendrocytes were increased by GM administration after CPZ exposure. In addition, GM attenuated a decrease in myelin basic protein immunoreactivity caused by CPZ administration. Taken together, our findings suggest that GM administration ameliorated the myelin deficit by mature oligodendrocyte formation and remyelination in the mPFC of CPZ-fed mice. The present findings provide experimental evidence supporting the role for GM and its possible use as a remedy for schizophrenia symptoms by promoting the differentiation of progenitor cells to and myelination by oligodendrocytes. PMID:24190599

  10. Application of artificial neural networks for modeling of the treatment of wastewater contaminated with methyl tert-butyl ether (MTBE) by UV/H2O2 process

    International Nuclear Information System (INIS)

    During the last two decades, methyl tert-butyl ether (MTBE) has been widely used as an additive to gasoline (up to 15%) both to increase the octane number and as a fuel oxygenate to improve air quality by reducing the level of carbon monoxide in vehicle exhausts. The present work mainly deals with photooxidative degradation of MTBE in the presence of H2O2 under UV light illumination (30 W). We studied the influence of the basic operational parameters such as initial concentration of H2O2 and irradiation time on the photodegradation of MTBE. The oxidation rate of MTBE was low when the photolysis was carried out in the absence of H2O2 and it was negligible in the absence of UV light. The addition of proper amount of hydrogen peroxide improved the degradation, while the excess hydrogen peroxide could quench the formation of hydroxyl radicals (·OH). The semi-log plot of MTBE concentration versus time was linear, suggesting a first order reaction. Therefore, the treatment efficiency was evaluated by figure-of-merit electrical energy per order (E Eo). Our results showed that MTBE could be treated easily and effectively with the UV/H2O2 process with E Eo value 80 kWh/m3/order. The proposed model based on artificial neural network (ANN) could predict the MTBE concentration during irradiation time in optimized conditions. A comparison between the predicted results of the designed ANN model and experimental data was also conducted

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-10-06

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

  12. Atmospheric Chemistry of Six Methyl-perfluoroheptene-ethers Used as Heat Transfer Fluid Replacement Compounds: Measured OH Radical Reaction Rate Coefficients, Atmospheric Lifetimes, and Global Warming Potentials

    Science.gov (United States)

    Jubb, A. M.; Gierczak, T.; Baasandorj, M.; Waterland, R. L.; Burkholder, J. B.

    2013-12-01

    Mixtures of methyl-perfluoroheptene-ethers (C7F13OCH3, MPHEs) are currently in use as a replacement for perfluorinated alkane (PFC) and polyether mixtures (both persistent greenhouse gases with atmospheric lifetimes >1000 years) used as heat transfer fluids. Currently, the atmospheric fate of the MPHE isomers are not well characterized, however, reaction with the OH radical is expected to be a dominant tropospheric loss process for these compounds. In order to assess the atmospheric lifetimes and environmental implications of MPHE use, rate coefficients for MPHE isomers' reaction with OH radicals are desired. In the work presented here, rate coefficients, k, for the gas-phase reaction of the OH radical with six MPHEs commonly used in commercial mixtures (isomers and stereoisomers) and their deuterated analogs (d3-MPHE) were determined at 296 K using a relative rate method with combined gas-chromatography/IR spectroscopy detection. A range of OH rate coefficient values was observed, up to a factor of 20× different, between the MPHE isomers with the (E)-stereoisomers exhibiting the greatest reactivity. The measured OH reaction rate coefficients for the d3-MPHE isomers were lower than the observed MPHE values although a large range of k values between isomers was still observed. The reduction in reactivity with deuteration signifies that the MPHE + OH reaction proceeds via both addition to the olefinic C=C bond and H-abstraction from the methyl ester group. OH addition to the C=C bond was determined to be the primary reaction channel. Atmospheric lifetimes with respect to the OH reaction for the six MPHE isomers were found to be in the range of days to months. The short lifetimes indicate that MPHE use will primarily impact tropospheric local and regional air quality. A MPHE atmospheric degradation mechanism will be presented. As part of this work, radiative efficiencies and global warming potentials (GWPs) for the MPHE isomers were estimated based on measured

  13. A Convenient and Efficient Procedure for Oxime Ethers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Acetophenone oxime and benzaldehyde oxime were converted to oxime ethers in the presence of alkyl halide or methyl sulfate and KOH in aqueous DMSO in 5 to 70 min. The yields of oxime ethers were 70 - 96%.

  14. Studies on Excess Volume, Viscosity, and Speed of Sound of Binary Mixtures of Methyl Benzoate in Ethers at T=(303.15,308.15, and 313.15) K

    OpenAIRE

    Rathnam, M. V.; Ambavadekar, Devappa R.; Nandini, M.

    2013-01-01

    Densities, viscosities, and speed of sound have been determined at T = (303.15, 308.15, and 313.15) K for the binary mixtures of methyl benzoate with tetrahydrofuran, 1,4-dioxane, anisole, and butyl vinyl ether over the entire range of composition. Using these measured values, excess volume VE, deviation in viscosities Δη, excess Gibb’s free energy of activation for viscous flow ΔG*E, and deviation in isentropic compressibility Δks have been calculated. These calculated binary data have been...

  15. Multifunctional Poly(methyl vinyl ether-co-maleic anhydride)-graft-hydroxypropyl-β-cyclodextrin Amphiphilic Copolymer as an Oral High-Performance Delivery Carrier of Tacrolimus.

    Science.gov (United States)

    Zhang, Dong; Pan, Xiaolei; Wang, Shang; Zhai, Yinglei; Guan, Jibin; Fu, Qiang; Hao, Xiaoli; Qi, Wanpeng; Wang, Yingli; Lian, He; Liu, Xiaohong; Wang, Yongjun; Sun, Yinghua; He, Zhonggui; Sun, Jin

    2015-07-01

    In order to improve oral bioavailability of tacrolimus (FK506), a novel poly(methyl vinyl ether-co-maleic anhydride)-graft-hydroxypropyl-β-cyclodextrin amphiphilic copolymer (CD-PVM/MA) is developed, combining the bioadhesiveness of PVM/MA, P-glycoprotein (P-gp), and cytochrome P450-inhibitory effect of CD into one. The FK506-loaded nanoparticles (CD-PVM/MA-NPs) were obtained by solvent evaporation method. The physiochemical properties and intestinal absorption mechanism of FK506-loaded CD-PVM/MA-NPs were characterized, and the pharmacokinetic behavior was investigated in rats. FK506-loaded CD-PVM/MA-NPs exhibited nanometer-sized particles of 273.7 nm, with encapsulation efficiency as high as 73.3%. FK506-loaded CD-PVM/MA-NPs maintained structural stability in the simulated gastric fluid, and about 80% FK506 was released within 24 h in the simulated intestinal fluid. The permeability of FK506 was improved dramatically by CD-PVM/MA-NPs compared to its solution, probably due to the synergistic inhibition effect of P-gp and cytochrome P450 3A (CYP3A). The intestinal biodistribution of fluorescence-labeled CD-PVM/MA-NPs confirmed its good bioadhesion to the rat intestinal wall. Two endocytosis pathways, clathrin- and caveolae-mediated endocytosis, were involved in the cellular uptake of CD-PVM/MA-NPs. The important role of lymphatic transport in nanoparticles' access to the systemic circulation, about half of the contribution to oral bioavailability, was observed in mesenteric lymph duct ligated rats. The AUC0-24 of FK506 loaded in nanoparticles was enhanced up to 20-fold compared to FK506 solutions after oral administration. The present study suggested that the novel multifunctional CD-PVM/MA is a promising efficient oral delivery carrier for FK506, due to its ability in solubilization, inhibitory effects on both P-gp and CYP 3A, high bioadhesion, and sustained release capability. PMID:26024817

  16. Quercetin 3-O-methyl ether protects FL83B cells from copper induced oxidative stress through the PI3K/Akt and MAPK/Erk pathway

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Hsiao-Ling, E-mail: lily1001224@gmail.com [Department of Life Sciences, Tzu Chi University, Hualien, Taiwan (China); Li, Chia-Jung, E-mail: 97751101@stmail.tcu.edu.tw [Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan (China); Huang, Lin-Huang, E-mail: yg1236@yahoo.com.tw [School of Medicine, Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan (China); Chen, Chun-Yao, E-mail: cychen@mail.tcu.edu.tw [Department of Life Sciences, Tzu Chi University, Hualien, Taiwan (China); Tsai, Chun-Hao, E-mail: 100726105@stmail.tcu.edu.tw [Department of Life Sciences, Tzu Chi University, Hualien, Taiwan (China); Lin, Chun-Nan, E-mail: lincna@cc.kmu.edu.tw [Faculty of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Biological Science and Technology, School of Medicine, China Medical University, Taichung, Taiwan (China); Hsu, Hsue-Yin, E-mail: hsueyin@mail.tcu.edu.tw [Department of Life Sciences, Tzu Chi University, Hualien, Taiwan (China)

    2012-10-01

    Quercetin is a bioflavonoid that exhibits several biological functions in vitro and in vivo. Quercetin 3-O-methyl ether (Q3) is a natural product reported to have pharmaceutical activities, including antioxidative and anticancer activities. However, little is known about the mechanism by which it protects cells from oxidative stress. This study was designed to investigate the mechanisms by which Q3 protects against Cu{sup 2+}-induced cytotoxicity. Exposure to Cu{sup 2+} resulted in the death of mouse liver FL83B cells, characterized by apparent apoptotic features, including DNA fragmentation and increased nuclear condensation. Q3 markedly suppressed Cu{sup 2+}-induced apoptosis and mitochondrial dysfunction, characterized by reduced mitochondrial membrane potential, caspase-3 activation, and PARP cleavage, in Cu{sup 2+}-exposed cells. The involvement of PI3K, Akt, Erk, FOXO3A, and Mn-superoxide dismutase (MnSOD) was shown to be critical to the survival of Q3-treated FL83B cells. The liver of both larval and adult zebrafish showed severe damage after exposure to Cu{sup 2+} at a concentration of 5 μM. Hepatic damage induced by Cu{sup 2+} was reduced by cotreatment with Q3. Survival of Cu{sup 2+}-exposed larval zebrafish was significantly increased by cotreatment with 15 μM Q3. Our results indicated that Cu{sup 2+}-induced apoptosis in FL83B cells occurred via the generation of ROS, upregulation and phosphorylation of Erk, overexpression of 14-3-3, inactivation of Akt, and the downregulation of FOXO3A and MnSOD. Hence, these results also demonstrated that Q3 plays a protective role against oxidative damage in zebrafish liver and remarked the potential of Q3 to be used as an antioxidant for hepatocytes. Highlights: ► Protective effects of Q3 on Cu{sup 2+}-induced oxidative stress in vitro and in vivo. ► Cu{sup 2+} induced apoptosis in FL83B cells via ROS and the activation of Erk. ► Q3 abolishes Cu{sup 2+}-induced apoptosis through the PI3K/Akt and MAPK

  17. Phase Behavior of Poly(vinylidene fluoride)-graft-poly(diethylene glycol methyl ether methacrylate) in Alcohol-Water System: Coexistence of LCST and UCST.

    Science.gov (United States)

    Kuila, Atanu; Maity, Nabasmita; Chatterjee, Dhruba P; Nandi, Arun K

    2016-03-10

    A thermoresponsive polymer poly(diethylene glycol methyl ether methacrylate) (PMeO2MA) is grafted from poly(vinylidene fluoride) (PVDF) backbone by using a combined ATRC and ATRP technique with a high conversion (69%) of the monomer to produce the graft copolymer (PD). It is highly soluble polymer and its solution property is studied by varying polarity in pure solvents (water, methanol, isopropanol) and also in mixed solvents (water-methanol and water-isopropanol) by measuring the hydrodynamic size (Z-average) of the particles by dynamic light scattering (DLS). The variation of Z-average size with temperature of the PD solution (0.2%, w/v) indicates a lower critical solution temperature (LCST)-type phase transition (TPL) in aqueous medium, an upper critical solution temperature (UCST)-type phase transition (TPU) in isopropanol medium, and no such phase transition for methanol solution. In the mixed solvent (water + isopropanol) at 0-20% (v/v) isopropanol the TPL increases, whereas the TPU decreases at 92-100% with isopropanol content. For the mixture 20-90% isopropanol, PD particles having larger sizes (400-750 nm) exhibit neither any break in Z-average size-temperature plot nor any cloudiness, indicating their dispersed swelled state in the medium. In the methanol + water mixture with methanol content of 0-30%, TPL increases, and at 40-60% both UCST- and LCST-type phase separations occur simultaneously, but at 70-90% methanol the swelled state of the particles (size 250-375 nm) is noticed. For 50 vol % methanol by varying polymer concentration (0.07-0.2% w/v) we have drawn a quasibinary phase diagram that indicates an approximate inverted hourglass phase diagram where a swelled state exists between two single phase boundary produced from LCST- and UCST-type phase transitions. An attempt is made to understand the phase separation process by temperature-dependent (1)H NMR spectroscopy along with transmission electron microscopy. PMID:26859626

  18. Equation of state for methyl tert-butyl ether%甲基叔丁基醚的状态方程

    Institute of Scientific and Technical Information of China (English)

    周永; 吴江涛

    2012-01-01

    In this work, the equation of state for methyl tert-butyl ether (MTBE) is developed based on the experimental data in literature using the Helmholtz energy as the fundamental property with independent variables of density and temperature. Overall, the uncertainty of the equation of state is 1.0% in vapor pressure bellow 430 K and increases with temperature due to a lack of experimental data. The uncertainty in density ranges from 0. 1% in the liquid region to 1.0% elsewhere, including the critical and vapor regions. The uncertainties in the properties related to energy (such as heat capacity and sound speed) are estimated to be 0. 5%. In the critical region, the uncertainties are higher for all properties except vapor pressure. The behavior of the equation of state is reasonable within the region of validity and at higher and lower temperatures and pressures.%利用公开发表的实验数据开发了甲基叔丁基醚(MTBE)的状态方程,方程以Helmholtz自由能为显式、以温度和密度为自变量.方程计算饱和蒸气压的不确定度430 K以下为1.0%,随着温度的升高,由于缺少实验数据不确定度增大为2.0%.方程计算密度的不确定度由液相区的0.2%变到临界区和气相区的1.0%.方程计算能量相关物性(如比热容、音速)的不确定度为0.5%.临界区,除了饱和蒸气压,方程计算所有其他热力学性质的不确定度都较高.本文方程不但能准确地复现实验数据,而且方程的外推性也是合理的.

  19. Measurement of methyl tert-butyl ether and tert-butyl alcohol in human blood by purge-and-trap gas chromatography-mass spectrometry using an isotope-dilution method.

    Science.gov (United States)

    Bonin, M A; Ashley, D L; Cardinali, F L; McCraw, J M; Wooten, J V

    1995-01-01

    We developed an isotope-dilution method for measuring methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) in whole human blood using a purge-and-trap gas chromatographic-mass spectrometric method. The labeled analogues for MTBE and TBA were [2H12]methyl tert-butyl ether and [2H9]-tert-butyl alcohol, respectively. Volatiles were removed from the blood by direct helium purging of the liquid; were trapped on a Tenax trap; and were desorbed, cryofocused, and chromatographed on a DB-624 capillary column that was connected directly to the ion source of a mass spectrometer. Detection was by mass analysis using a double-focusing magnetic-sector mass spectrometer operating in the full-scan mode at the medium mass resolution of 3000. For the isotope-dilution method, the minimum detection limits in blood (5-10 mL) are 0.01 microgram/L for MTBE and 0.06 microgram/L for TBA. The isotope-dilution method proved to be a big improvement in recovery, reproducibility, and sensitivity over our previous analytical method, which used the labeled ketone, [4-2H3]-2-butanone, as the internal standard for both MTBE and TBA. The isotope-dilution method has sufficient sensitivity for monitoring blood levels of MTBE and TBA in populations exposed to oxygenated fuels containing MTBE. PMID:7564298

  20. 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)

  1. A Comparison of Effects of Ambient Pressure on the Atomization Performance of Soybean Oil Methyl Ester and Dimethyl Ether Sprays Comparaison des effets de la pression ambiante sur l’atomisation en “spray” de methylester d’huile de soja et de dimethyléther

    OpenAIRE

    Kim H.J.; Park S.H.; Chon M.S.; Lee C. S.

    2010-01-01

    The purpose of this study is the experimental investigation of Soybean oil Methyl Ester (SME) and DiMethyl Ether (DME) spray characteristics injected through the common-rail injection system under various ambient pressures. A high pressure chamber that can be pressurized up to 4 MPa was utilized for a change of ambient pressure. In order to compare the spray development and atomization characteristics, the images of SME and DME were obtained by using a high speed camera with two metal ha...

  2. 40 CFR 721.5560 - Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz[c...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with... Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz oxaphosphorin-6... identified as formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with...

  3. 用于脱除C5及MTBE中甲醇的渗透汽化膜研究%Study on Pervaporation Membranes for Removing Methanol from C5 or Methyl Tert-butyl Ether Mixtures

    Institute of Scientific and Technical Information of China (English)

    张林; 陈欢林; 周志军; 钱锦文; 高从堦; 潘祖仁

    2003-01-01

    Several pervaporation membranes, cellulose acetate (CA), polyvinylbutyral (PVB), poly(MMA-co-AA),MMA-AA-BA, CA/PVB blend and CA/poly(MMA-co-AA) blend, were prepared, and their pervaporation properties were evaluated by separation of methanol/C5 or methanol/MTBE (methyl tert-butyl ether). The results shows that the CA composite membrane has a high separation performance (flux Jmethanol = 350 g.m-2.h-1 and separation factor α>400) for methanol/C5 mixtures, and the pervaporation characteristics of MMA-AA-BA copolymer membranes changes with the ratio of copolymer. For CA/poly(MMA-co-AA) blend membrane, the pervaporation performance is improved in comparison with CA or poly(MMA-co-AA) membrane. From the experiment of CA/PVB blend membranes for methanol/MTBE mixture, it is found that the compatibility of blends may affect the separation features of blend membrane.

  4. Studies on Excess Volume, Viscosity, and Speed of Sound of Binary Mixtures of Methyl Benzoate in Ethers at T=(303.15,308.15, and 313.15 K

    Directory of Open Access Journals (Sweden)

    M. V. Rathnam

    2013-01-01

    Full Text Available Densities, viscosities, and speed of sound have been determined at T = (303.15, 308.15, and 313.15 K for the binary mixtures of methyl benzoate with tetrahydrofuran, 1,4-dioxane, anisole, and butyl vinyl ether over the entire range of composition. Using these measured values, excess volume VE, deviation in viscosities Δη, excess Gibb’s free energy of activation for viscous flow ΔG*E, and deviation in isentropic compressibility Δks have been calculated. These calculated binary data have been fitted to Redlich-Kister equation to determine the appropriate coefficients. The values of excess volume VE and deviation in viscosities Δη are negative over the entire range of composition for all the binary systems at the studied temperatures. The behavior of these parameters with composition of the mixture has been discussed in terms of molecular interactions between the components of liquids.

  5. The Search for a Complex Molecule in a Selected Hot Core Region: A Rigorous Attempt to Confirm trans-Ethyl Methyl Ether toward W51 e1/e2

    CERN Document Server

    Carroll, P Brandon; Blake, Geoffrey A; Apponi, A J; Ziuyrs, L M; Remijan, Anthony

    2014-01-01

    An extensive search has been conducted to confirm transitions of \\textit{trans}-ethyl methyl ether (tEME, C$_2$H$_5$OCH$_3$), toward the high mass star forming region W51 e1/e2 using the 12 m Telescope of the Arizona Radio Observatory (ARO) at wavelengths from 2 mm and 3 mm. In short, we cannot confirm the detection of tEME toward W51 e1/e2 and our results call into question the initial identification of this species by \\citet{FuchsSpace}. Additionally, reevaluation of the data from the original detection indicates that tEME is not present toward W51 e1/e2 in the abundance reported by Fuchs and colleagues. Typical peak-to-peak noise levels for the present observations of W51 e1/e2 were between 10 - 30 mK, yielding an upper limit of the tEME column density of $\\leq$ 1.5 $\\times$ 10$^{15}$ cm$^{-2}$. This would make tEME at least a factor 2 times less abundant than dimethyl ether (CH$_3$OCH$_3$) toward W51 e1/e2. We also performed an extensive search for this species toward the high mass star forming region Sgr...

  6. Fabrication and characterization of superparamagnetic and thermoresponsive hydrogels based on oleic-acid-coated Fe3O4 nanoparticles, hexa(ethylene glycol) methyl ether methacrylate and 2-(acetoacetoxy)ethyl methacrylate

    International Nuclear Information System (INIS)

    Stimuli-responsive hydrogel nanocomposites comprised of swollen polymer networks, in which magnetic nanoparticles are embedded, are a relatively new class of 'smart' soft materials presenting a significant impact on various technological and biomedical applications. A novel approach for the fabrication of hydrogel nanocomposites exhibiting temperature- and magneto-responsive behavior involves the random copolymerization of hexa(ethylene glycol) methyl ether methacrylate (HEGMA, hydrophilic, thermoresponsive) and 2-(acetoacetoxy)ethyl methacrylate (AEMA, hydrophobic, metal-chelating) in the presence of preformed oleic-acid-coated magnetite nanoparticles (OA.Fe3O4). In total, two series of hydrogel nanocomposites have been prepared in two different solvent systems: ethyl acetate (series A) and tetrahydrofuran (series B). The degrees of swelling (DSs) of all conetworks were determined in organic and in aqueous media. The nanocrystalline phase adopted by the embedded magnetic nanoparticles was investigated by X-ray diffraction (XRD) spectroscopy. The obtained diffraction patterns indicated the presence of magnetite (Fe3O4). Deswelling kinetic studies that were carried out at ∼60 oC in water demonstrated the thermoresponsive properties of the hydrogel nanocomposites, attributed to the presence of the hexaethylene glycol side chains within the conetworks. Moreover, thermal gravimetric analysis (TGA) measurements showed that these materials exhibited superior thermal stability compared to the pristine hydrogels. Further to the characterization of compositional and thermal properties, the assessment of magnetic characteristics by vibrational sample magnetometry (VSM) disclosed superparamagnetic behavior. The tunable superparamagnetic behavior exhibited by these materials depending on the amount of magnetic nanoparticles incorporated within the networks combined with their thermoresponsive properties may allow for their future exploitation in the biomedical field

  7. Synthesis of the insecticide prothrin and its analogues from biomass-derived 5-(Chloromethyl) furfural

    Science.gov (United States)

    Prothrin, a synthetic pyrethroid insecticide, was synthesized from the biomass-derived platform chemical 5 (chloromethyl)furfural in six steps and overall 65% yield. Two structural analogues of prothrin were also prepared following the same synthetic approach. Preliminary testing of these furan-base...

  8. Molecularly Imprinted Polymers on Chloromethyl Polystyrene Resin Prepared via RAFT Polymerization

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Surface molecularly imprinted polymers (SMIP) was prepared via the reversible addition-fragmentation chain transfer (RAFT) polymerization on the chloromethyl polystyrene resin (CPR) in the presence of the template D-phenylalanine. The structure of SMIP was characterized by FTIR and SEM. The adsorption behavior of D-phenylalanine of SMIP was preliminarily investigated.

  9. 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)

    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)

  10. SENSORY, SYMPTOMATIC, INFLAMMATORY, AND OCULAR RESPONSES TO AND THE METABOLISM OF METHYL TERTIARY BUTYL ETHER IN A CONTROLLED HUMAN EXPOSURE EXPERIMENT

    Science.gov (United States)

    In response to elevated ambient carbon monoxide (CO) due to incomplete combustion of automotive fuels, the Clear Air Act mandates that CO reduction be obtained by adding oxygenates to the fuel (oxyfuel) in areas of non-attainment. In 1992 the addition of methyl tertiary butyl eth...

  11. Bis(μ-2-tert-butyl-phenyl-imido-1:2κN:N)chlorido-2κCl-(diethyl ether-1κO)(2η-penta-methyl-cyclo-penta-dien-yl)lithiumtantalum(V).

    Science.gov (United States)

    Cole, Jacqueline M; Chan, Michael C W; Gibson, Vernon C; Howard, Judith A K

    2011-06-01

    In the title compound, [LiTa(C(10)H(15))(C(10)H(13)N)(2)Cl(C(4)H(10)O)], the Ta(V) atom is coordinated by a η(5)-penta-methyl-cyclo-penta-dienyl (Cp*) ligand, a chloride ion and two N-bonded 2-tert-butyl-phenyl-imide dianions. With respect to the two N atoms, the chloride ion and the centroid of the Cp* ring, the tantalum coordination geometry is approximately tetra-hedral. The lithium cation is bonded to both the 2-tert-butyl-phenyl-imide dianions and also a diethyl ether mol-ecule, in an approximate trigonal planar arrangement. The Ta⋯Li separation is 2.681 (15) Å. In the crystal, a weak C-H⋯Cl inter-action links the mol-ecules. When compared to the 2,6-diisopropyl-phenyl-imide analogue ('the Wigley derivative') of the title compound, the two structures are conformationally matched with an overall r.m.s. difference of 0.461Å. PMID:21754594

  12. 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)

    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 GABAA 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 GABAA 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. GABAA receptor may play an important role in the MTBE-induced impairment of learning and memory by regulating the phosphorylation of ERK in the hippocampus.

  13. Volumetric and viscometric properties of binary mixtures of {methyl tert-butyl ether (MTBE) + alcohol} at several temperatures and p = 0.1 MPa: Experimental results and application of the ERAS model

    International Nuclear Information System (INIS)

    Highlights: → Binary mixtures of MTBE + alcohol have been studied. → Volumetric and viscometric properties have been determined at several temperatures. → Excess molar volumes have been used to test the applicability of the ERAS model. → The results are discussed in terms of chemical and structural effects. - Abstract: Densities and viscosities of binary mixtures of {methyl tert-butyl ether (MTBE) + methanol, or +ethanol, or +1-propanol, or +2-propanol, or +1-butanol, or +1-pentanol, or +1-hexanol} have been determined as a function of composition at several temperatures and atmospheric pressure. The temperatures studied were (293.15, 298.15, 303.15, and 308.15) K. The experimental results have been used to calculate the excess molar volume (VmE) and viscosity deviation (Δη). Both VmE and Δη values were negative over the entire range of mole fraction for all temperatures and systems studied. Moreover, the VmE values have been used to test the applicability of the Extended Real Associated Solution (ERAS) model.

  14. EXPERIMENTAL INVESTIGATIONS OF REAL TIME SECONDARY CO-INJECTION OF WATER – DIETHYL ETHER SOLUTION IN DI-DIESEL ENGINE FUELLED WITH PALM KERNEL METHYL ESTER

    Directory of Open Access Journals (Sweden)

    Y. V. V. SATYANARAYANAMURTHY

    2012-12-01

    Full Text Available In this investigation tests were conducted on single cylinder diesel engine fuelled with neat diesel and biodiesel palm kernel methyl ester as a base line fuel with secondary injection of Water-DEE solution through the inlet manifold. A real time control systems consists of electronic unit pump that delivers 5% to 25% vol. Water-DEE solution through injector tip mounted nearer to the inlet manifold under a pressure of 3 kgf/cm2. NOx emissions reduced to a level of 500 ppm with simultaneous reduction of soot especially for PKME. However for 15% vol. of Water-DEE injection the HC emissions are closely tallying with that of neat diesel. A global overview of the results has shown that the 15% Water-DEE solution is the optimal blend based on performance and emission characteristics.

  15. Application of Ultrasonic Attenuation Measurements in the Studies on Macromolecular Conformational Behaviors--Phase Behavior of the Aqueous Solution of Poly(vinyl methyl ether) Sensitive to Temperature and the Modification of the Behavior by Using Poly(ac

    Institute of Scientific and Technical Information of China (English)

    WANG,Gong-Zheng(王公正); FANG,Yu(房喻); SHANG,Zhi-Yuan(尚志远); ZHANG,Ying(张颖); HU,Dao-Dao(胡道道)

    2004-01-01

    The phase behavior of the aqueous solution of poly(vinyl methyl ether) (PVME) sensitive to temperature and the modification of the behavior by using poly(acrylic acid) (PAA) have been studied by ultrasonic attenuation measurements and fluorescence probe techniques. It has been observed that PVME solution is transparent at room temperature and becomes turbid upon heating. The solution turns clear again as soon as the temperature is decreased to room temperature. The heating and cooling process can be repeated for many times. The phase behavior of the solution sensitive to temperature is attributed to the conformational changes of the polymer. PVME may adopt an open coil conformation at room temperature. With this conformation, the polymer is well miscible with the solvent, water, and thereby the system is a real solution. The polymer may adopt a compact coil conformation when the temperature is higher than a specific value, which is called the LCST (the lower critical solution temperature) of PVME. In this case, the polymer tangles to each other and forms various aggregates, which can scatter incident light and ultrasonic waves greatly, resulting in the phase separation. Introduction of PAA decreases the temperature sensitivity of the phase behavior of the polymer. The nature of the inhibition is attributed to the complexation of PAA with PVME and the strong hydrophilicity of PAA. Results from fluorescence probe studies are in accordance with those from ultrasonic attenuation measurements, indicating again that the ultrasonic attenuation method can be successfully used for the qualitative studies of polymer conformations and complexation between polymers.

  16. 40 CFR 721.5585 - 4,4′-(1-methylethylidene)bisphenol, polymer with (chloromethyl)oxirane and a diamine (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 4,4â²-(1-methylethylidene)bisphenol...-methylethylidene)bisphenol, polymer with (chloromethyl)oxirane and a diamine (generic). (a) Chemical substance and...-methylethylidene)bisphenol, polymer with (chloromethyl) oxirane and a diamine (PMN P-97-0916) is subject...

  17. The solubility and environmental characteristics of diesel ethers

    International Nuclear Information System (INIS)

    Concern over diesel particulate emissions has been ongoing for the past 2 decades, and a number of agencies have shown that adding ethers to diesel engines can reduce these particulates. However, the exact mechanism is not known. Methyl tert-butyl ether (MTBE) has been used for several years to improve the performance of gasoline engines. MTBE is very soluble in water and leaches out of the gasoline and into groundwater very easily. MTBE is being phased out due to this problem. This paper presented the results of a project initiated to evaluate candidate ethers for their solubility in water as well as other environmental characteristics. The ethers may also have the potential for reducing the emissions from diesel engines. Thirty-four ethers were tested for solubility, aquatic toxicity and biological oxygen demand. The tests were conducted due to concerns that MTBE has been shown to cause contamination as a result of its high solubility. The study focused on screening potential diesel ethers for a variety of acceptability criteria such as solubility, aquatic toxicity and degradation potential. A review of measuring methods, materials and instrumentation procedures was presented, along with solubility measurements. The stoichiometry and physical properties of petroleum ethers were also provided as well as test procedures for aquatic toxicity and microtox. A generalized property prediction model was presented. It was concluded that the properties, toxicity and degradation of the ethers vary widely. Solubility correlates with the structure of the ethers: di and tri-ethers are very soluble and any methyl ether also has high solubility. Biochemical oxygen testing of all tested ethers was low, indicating a low breakdown with typical bacterial cultures. The aquatic toxicity of the ethers is variable and correlates inversely with the solubility. The higher the solubility, the lower the toxicity. 24 refs., 10 tabs

  18. Facile synthesis of hypercrosslinked resins via chloromethylation and continuous condensation of simple aryl molecules

    Indian Academy of Sciences (India)

    Xiaoyan Zhang; Qiu Jin; Libo Dai; Siguo Yuan

    2011-07-01

    A sort of non-polystyrene type hypercrosslinked resin was firstly synthesized through chloromethylation of simple aryl molecules (benzene, toluene, naphthalene, diphenyl), succedent continuous Friedel–Crafts alkylation polymerization and post-crosslinking reaction. The chemical and porous structures of these novel resins were characterized with BET, FT–IR and elementary analysis, respectively. The results showed that these novel adsorptive materials possessing abundant crosslinked networks had high specific surface areas (up to 1191.26 m2/g), large pore volumes (0.2–1.4 ml/g), narrow pore size distributions (mainly in the range of micropores and small mesopores).

  19. Spectroscopic, antifungal and antibacterial studies of 1,4-bis-(chloromethyl)-naphthalene

    International Nuclear Information System (INIS)

    H/sup 1/ and C/sup 13/-NMR spectra indicate that naphthalene portion of 1,4-bis-(chloromethyl)-naphthalene was slightly twisted due to C/sup 8/ - H - Cl bonding. The electrons distribution on magnetically equivalent carbons became uneven that is why ten carbon peaks instead of five pairs of magnetically equivalent carbons had appeared in C/sup 13/-NMR spectra. Due to C/sup 8/ - H - Cl bonding, extension and contraction in bond lengths from their normal positions had occurred. Similar case was with H/sup 1/-NMR of the said compound. The molecule also showed antifungal and antibacterial properties. (author)

  20. 甲基乙烯醚和臭氧反应机理和动力学的理论研究%Theoretical Studies on the Kinetics and Mechanisms of Reactions for Methyl Vinyl Ether and Ozone

    Institute of Scientific and Technical Information of China (English)

    龙波; 黄明强; 王振亚; 张为俊

    2008-01-01

    利用量子化学从头计算的方法对甲基乙烯醚的两个异构体之间的转化、臭氧与甲晕乙烯醚的环加成反应、臭氧化物的裂解以及主要氧化物异构体的之间的转化的反应通道进行了研究,并用经典过渡态理论存在280~440 K计算了反应的速率常数.对于臭氧和甲基乙烯醚的反应,考虑了臭氧从两个可能的/不同方向进攻甲基乙烯醚.计算结果表明,顺式-甲基乙烯醚是比较稳定的,但是反式-甲基乙烯醚与臭氧反应所要跨越比较低的能垒,分别为1.7和7.5 kJ/mol,而其产物更稳定,在形成的臭氧化物中占绝对比例,臭氧化物的裂解主要导致CH2-OO的生成,在298 K时的反应速率常数为4.8×10-17 cm3(molecule·S).%The interconversion between the two distinct isomers of methyl vinyl ether(MVE),the formation of the primary ozonides from O3-initated reactions of MVE,the transformation between the primary ozonides,and the subsequent fragmentation were studied using quantum chemical methods at the BHandHLYP/6-311++G(d,P)level of theory for optimized geometries and frequency calculations and at the QCISD/6-31G(d,P)level for the single point energy calculations.The rate coefficients were calculated for the temper-ature range 280-440 K by using the canonical transition state theory(TST).For ozone addition to MVE,there are two difierent possibilities discussed on the basis of two different possible orientations for ozone attack. The results of the theoretical study indicate that although the synperiplanar-MVE is 7.11 kJ/mol more stable than the antiperiplanar-MVE.the antiperiplanar-MVE plays a more important role in formation of the primary ozonides because the primary ozonides formed from the ozone addition antiperiplanar-MVE are more stable and the energy barriers corresponding to transition states are lower.The interconversion between the primary ozonides formed from the ozone addition to antiperiplanar-MVE is the most accessible

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

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Keun-Chan; Stringfellow, William T.

    2003-10-02

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

  2. Secondary interactions in N-(chloromethyl)pyridinium chlorides (n = 2, 3, 4).

    Science.gov (United States)

    Jones, Peter G; Vancea, Fabiola; Herbst-Irmer, Regine

    2002-11-01

    In the isomeric title compounds, viz. 2-, 3- and 4-(chloromethyl)pyridinium chloride, C(6)H(7)ClN(+).Cl(-), the secondary interactions have been established as follows. Classical N-H.Cl(-) hydrogen bonds are observed in the 2- and 3-isomers, whereas the 4-isomer forms inversion-symmetric N-H(.Cl(-).)(2)H-N dimers involving three-centre hydrogen bonds. Short Cl.Cl contacts are formed in both the 2-isomer (C-Cl.Cl(-), approximately linear at the central Cl) and the 4-isomer (C-Cl.Cl-C, angles at Cl of ca 75 degrees ). Additionally, each compound displays contacts of the form C-H.Cl, mainly to the Cl(-) anion. The net effect is to create either a layer structure (3-isomer) or a three-dimensional packing with easily identifiable layer substructures (2- and 4-isomers). PMID:12415176

  3. Preparation of magnetic latexes functionalized with chloromethyl groups via emulsifier-free miniemulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Faridi-Majidi, Reza [School of Chemistry, University College of Science, Tehran University, Tehran (Iran, Islamic Republic of)]. E-mail: refaridi@khayam.ut.ac.ir; Sharifi-Sanjani, Naser [School of Chemistry, University College of Science, Tehran University, Tehran (Iran, Islamic Republic of)

    2007-04-15

    Functionalized crosslinked polystyrene-co-divinylbenzene-co-chloromethylstyrene magnetic latex particles were prepared via emulsifier-free miniemulsion polymerization using 2, 2' azobis (2-amidinopropane) dihydrochloride (V-50) as an initiator and in the presence of magnetite nanoparticles in the monomers. Transmission electron microscopy (TEM) proved the presence of magnetite nanoparticles in polymer particles. Differential scanning calorimetery (DSC) analysis of the product showed an exothermic signal due to crosslinking of chains through electrophilic aromatic substitution of phenyl groups with chloromethyl groups in the presence of the dispersed Fe{sub 3}O{sub 4} as Lewis acid. This was proven by thermogravimetric analysis (TGA) via the loss of gaseous HCl. The results were also compared with those of magnetite-free miniemulsion polymerization using V-50.

  4. Synthesis of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide – a tailor-made photoinitiator for dental adhesives

    OpenAIRE

    Moszner, Norbert; Lamparth, Iris; Angermann, Jörg; Fischer, Urs Karl; Zeuner, Frank; Bock, Thorsten; Liska, Robert; Rheinberger, Volker

    2010-01-01

    Because of the poor solubility of the commercially available bisacylphosphine oxides in dental acidic aqueous primer formulations, bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide (WBAPO) was synthesized starting from 3-(chloromethyl)-2,4,6-trimethylbenzoic acid by the dichlorophosphine route. The substituent was introduced by etherification with 2-(allyloxy)ethanol. In the second step, 3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoic acid was chlorinated...

  5. (Diethyl ether{1-[2-(1-methyl-1H-imidazol-2-yl-κN3-1,1-diphenylethyl]-(1,2,3,3a,7a-η-indenyl}lithium(I

    Directory of Open Access Journals (Sweden)

    Maxim V. Borzov

    2009-05-01

    Full Text Available In the title compound, [Li(C27H23N2(C4H10O], the Li atom possesses a nearly planar trigonal coordination environment (assuming the cyclopentadienyl ring of the indenyl group occupies one coordination place. The diethyl ether ligand adopts a nearly planar W-type conformation.

  6. Ether formulations of relativity

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, M.C.

    1980-12-01

    Contemporary ether theories are surveyed and criticized, 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 criticized. Cosmological evidence suggesting an ether is mentioned. Only ether theories formally identical to Relativity have been published in depth. They stand criticized 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. 103 references.

  7. Ether formulations of relativity

    International Nuclear Information System (INIS)

    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)

  8. Crystal structure of the inverse crown ether tetra-kis-[μ2-bis-(tri-methyl-sil-yl)amido]-μ4-oxido-dicobalt(II)disodium, [Co2Na2{μ2-N(SiMe3)2}4](μ4-O).

    Science.gov (United States)

    Hansen, Christopher B; Filatov, Alexander S; Hillhouse, Gregory L

    2016-06-01

    The title compound, [Co2Na2{μ2-N(SiMe3)2}4](μ4-O), (I), represents a new entry in the class of inverse crown ethers. In the mol-ecule, each Co atom is formally in the oxidation state +II. The structure contains one half of a unique mol-ecule per asymmetric unit with the central μ4-oxido ligand residing on an inversion center, leading to a planar coordination to the Na and Co atoms. In the crystal, bulky tri-methyl-silyl substituents prevent additional inter-actions with cobalt. However, weak inter-molecular Na⋯H3C-Si inter-actions form an infinite chain along [010]. The structure is isotypic with its Mg, Mn and Zn analogues. PMID:27308041

  9. Crystal structure of the inverse crown ether tetra­kis­[μ2-bis­(tri­methyl­sil­yl)amido]-μ4-oxido-dicobalt(II)disodium, [Co2Na2{μ2-N(SiMe3)2}4](μ4-O)

    Science.gov (United States)

    Hansen, Christopher B.; Filatov, Alexander S.; Hillhouse, Gregory L.

    2016-01-01

    The title compound, [Co2Na2{μ2-N(SiMe3)2}4](μ4-O), (I), represents a new entry in the class of inverse crown ethers. In the mol­ecule, each Co atom is formally in the oxidation state +II. The structure contains one half of a unique mol­ecule per asymmetric unit with the central μ4-oxido ligand residing on an inversion center, leading to a planar coordination to the Na and Co atoms. In the crystal, bulky tri­methyl­silyl substituents prevent additional inter­actions with cobalt. However, weak inter­molecular Na⋯H3C—Si inter­actions form an infinite chain along [010]. The structure is isotypic with its Mg, Mn and Zn analogues. PMID:27308041

  10. Bis(μ-2-tert-butyl­phenyl­imido-1:2κ2 N:N)chlorido-2κCl-(diethyl ether-1κO)(2η5-penta­methyl­cyclo­penta­dien­yl)lithiumtantalum(V)

    OpenAIRE

    Jacqueline M. Cole; Michael C. W. Chan; Gibson, Vernon C.; Judith A. K. Howard

    2011-01-01

    In the title compound, [LiTa(C10H15)(C10H13N)2Cl(C4H10O)], the TaV atom is coordinated by a η5-penta­methyl­cyclo­penta­dienyl (Cp*) ligand, a chloride ion and two N-bonded 2-tert-butyl­phenyl­imide dianions. With respect to the two N atoms, the chloride ion and the centroid of the Cp* ring, the tantalum coordination geometry is approximately tetra­hedral. The lithium cation is bonded to both the 2-tert-butyl­phenyl­imide dianions and also a diethyl ether mol­ecule, in an approximate trigonal...

  11. Imidazole-containing triblock copolymers with a synergy of ether and imidazolium sites

    OpenAIRE

    Jangu, Chainika; Wang, Jing-Han Helen; Wang, Dong; Fahs, Gregory B.; Heflin, James R.; Robert B. Moore; Colby, Ralph H.; Long, Timothy E.

    2015-01-01

    Reversible addition-fragmentation chain transfer (RAFT) polymerization enabled the synthesis of well-defined A-BC-A triblock copolymers containing a synergy of pendant ether and imidazolium sites. The soft central BC block comprises low Tg di(ethylene glycol) methyl ether methacrylate (DEGMEMA) and 1-(4-vinylbenzyl) methyl imidazolium units. External polystyrene blocks provide mechanical reinforcement within a nanoscale morphology. Dynamic mechanical analysis (DMA) of the A-BC-A triblock copo...

  12. Catalytic oxidation of dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Zelenay, Piotr; Wu, Gang; Johnston, Christina M.; Li, Qing

    2016-05-10

    A composition for oxidizing dimethyl ether includes an alloy supported on carbon, the alloy being of platinum, ruthenium, and palladium. A process for oxidizing dimethyl ether involves exposing dimethyl ether to a carbon-supported alloy of platinum, ruthenium, and palladium under conditions sufficient to electrochemically oxidize the dimethyl ether.

  13. Thermodynamic calculation and energy saving analysis of combined reaction system for production of dimethyl carbonate, methylal and dimethyl ether from methanol%甲醇为原料联合制备碳酸二甲酯、甲缩醛和二甲醚反应体系热力学计算及节能分析

    Institute of Scientific and Technical Information of China (English)

    丁晓墅; 李乃华; 王淑芳; 赵新强; 王延吉

    2015-01-01

    To achieve the target of the efficient, green, safe and energy saving synthesis of dimethyl carbonate, a combined reaction system with energy saving is proposed for synthesis of dimethyl carbonate, methylal and dimethyl ether from methanol. Thermodynamics of single reaction and the complex system is analyzed by Aspen Plus software. The results show that there is thermodynamic equilibrium limit for the synthesis of dimethyl carbonate from methanol in gas phase, to improve significantly equilibrium concentration of dimethyl carbonate higher reaction pressure and lower reaction temperature is necessary, even so, large amount of unreacted methanol must be recycled which consume a lot of energy. When synthesis of dimethyl carbonate is combined with methylal and dimethyl ether synthesis, the equilibrium conversion of methanol can be improved observably from 0.5%—5.9%to 91.7%—96.3%. Based on the thermodynamic calculations and kinetics of these reactions, a series process of three catalytic reactors are proposed for synthesis of dimethyl carbonate, methylal and dimethyl ether in order, and the system including reaction and separation processes is simulated. The results show that the mixture of methylal and dimethyl carbonate can be separated by simple distillation and the separation of dimethyl carbonate-H2O azeotrpoe need to employ pressure swing distillation. Mass concentration of three products can be reached above 99%. The process proposed could effectively solve the problems as follows: recycle of large amount un-reacted materials, high energy consumption, easy explosion and so on, which exist in the process for detached production of dimethyl carbonate and methylal.%围绕碳酸二甲酯的高效、绿色、安全、节能合成目标,构建了联合生产碳酸二甲酯、甲缩醛和二甲醚反应体系及节能工艺。借助Aspen Plus软件对独立反应及复杂体系进行了热力学分析。由结果可知,升高反应压力或降低温度可明显

  14. 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.

  15. Mechanism of inactivation of human leukocyte elastase by a chloromethyl ketone: kinetic and solvent isotope effect studies

    International Nuclear Information System (INIS)

    The mechanism of inactivation of human leukocyte elastase (HLE) by the chloromethyl ketone MeOSuc-Ala-Ala-Pro-Val-CH2Cl was investigated. The dependence of the first-order rate constant for inactivation on concentration of chloromethyl ketone is hyperbolic and suggests formation of a reversible Michaelis complex prior to covalent interaction between the enzyme and inhibitor. However, the observed Ki value is 10 microM, at least 10-fold lower than dissociation constants for complexes formed from interaction of HLE with structurally related substrates or reversible inhibitors, and suggests that Ki is a complex kinetic constant, reflecting the formation and accumulation of both the Michaelis complex and a second complex. It is proposed that this second complex is a hemiketal formed from attack of the active site serine on the carbonyl carbon of the inhibitor. The accumulation of this intermediate may be a general feature of reactions of serine proteases and chloromethyl ketones derived from specific peptides and accounts for the very low Ki values observed for these reactions. The solvent deuterium isotope effect (SIE) on the inactivation step (ki) is 1.58 +/- 0.07 and is consistent with rate-limiting, general-catalyzed attack of the active site His on the methylene carbon of the inhibitor with displacement of chloride anion. The general catalyst is thought to be the active site Asp. In contrast, the SIE on the second-order rate constant for HLE inactivation, ki/Ki, is inverse and equals 0.64 +/- 0.05

  16. The compound ethers of glycerin

    International Nuclear Information System (INIS)

    In this chapter of book authors describe several methods of receiving of compound ethers of glycerin. The important technic significance have compound glycerin ether and nitric acid. This compound receive by reaction of glycerin with fuming nitric acid

  17. Alkyl aryl ethers in lignite solubilization

    Energy Technology Data Exchange (ETDEWEB)

    Mustral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1985-03-01

    The FT-I.R. and /sup 1/H N.M.R. spectroscopic analyses of oils or maltenes from a Spanish lignite (Utrillas, Teruel), are reported. These oils were obtained by depolymerization with alkyl aromatic ethers (anisole, 3-methyl anisole and 1,3-dimethoxybenzene) catalyzed by Lewis acids ZnCl/sub 2/, AlCl/sub 3/, SbCl/sub 3/ and BF/sub 3/ (as boron trifluoride etherate), at atmospheric pressure and temperatures <220/sup 0/C. Bands due to aromatic ethers in the I.R. and N.M.R. spectra of the oils obtained by depolymerization indicate solvent incorporation. Oils obtained by direct lignite extraction showed 25% aromatic H and some H /sub i/ (approx. = 3%) without OH groups. These appeared in some oils obtained by depolymerization with AlCl/sub 3/ and were due to secondary reactions with the aromatic extract. Oils derived from processes with good yields showed increases in aromaticity. The extent of substitution of aromatic rings in oils obtained by depolymerization was less than for oils directly extracted. All the oils studied show a low degree of condensation.

  18. Propenyl ether monomers for photopolymerization

    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.

  19. Reaction Pathways and Energetics of Etheric C–O Bond Cleavage Catalyzed by Lanthanide Triflates

    Energy Technology Data Exchange (ETDEWEB)

    Assary, Rajeev S.; Atesin, Abdurrahman C.; Li, Zhi; Curtiss, Larry A.; Marks, Tobin J.

    2013-09-06

    Efficient and selective cleavage of etheric C-O bonds is crucial for converting biomass into platform chemicals and liquid transportation fuels. In this contribution, computational methods at the DFT B3LYP level of theory are employed to understand the efficacy of lanthanide triflate catalysts (Ln(OTf)3, Ln = La, Ce, Sm, Gd, Yb, and Lu) in cleaving etheric C-O bonds. In agreement with experiment, the calculations indicate that the reaction pathway for C-O cleavage occurs via a C-H → O-H proton transfer in concert with weakening of the C-O bond of the coordinated ether substrate to ultimately yield a coordinated alkenol. The activation energy for this process falls as the lanthanide ionic radius decreases, reflecting enhanced metal ion electrophilicity. Details of the reaction mechanism for Yb(OTf)3-catalyzed ring opening are explored in depth, and for 1-methyl-d3-butyl phenyl ether, the computed primary kinetic isotope effect of 2.4 is in excellent agreement with experiment (2.7), confirming that etheric ring-opening pathway involves proton transfer from the methyl group alpha to the etheric oxygen atom, which is activated by the electrophilic lanthanide ion. Calculations of the catalytic pathway using eight different ether substrates indicate that the more rapid cleavage of acyclic versus cyclic ethers is largely due to entropic effects, with the former C-O bond scission processes increasing the degrees of freedom/particles as the transition state is approached.

  20. Bacterial degradation of glycol ethers.

    Science.gov (United States)

    Kawai, F

    1995-12-01

    Assimilation of ethyleneglycol (EG) ethers by polyethyleneglycol-utilizing bacteria was examined. Ethyleneglycol ether-utilizing bacteria were also isolated from soil and activated sludge samples by enrichment-culture techniques. Three strains (4-5-3, EC 1-2-1 and MC 2-2-1) were selected and characterized as Pseudomonas sp. 4-5-3, Xanthobacter autotrophicus, and an unidentified gram-negative, non-spore-forming rod respectively. Their growth characteristics were examined: Pseudomonas sp. 4-5-3 assimilated EG (diethyleneglycol, DEG) monomethyl, monoethyl and monobutyl ethers, DEG, propanol and butanol. X. autotrophicus EC 1-2-1 grew well on EG monoethyl and monobutyl ethers, EG and primary alcohols (C1-C4), and slightly on EG monomethyl ether. The strain MC 2-2-1 grew on EG monomethyl ether, EG, primary alcohols (C1-C4), and 1,2-propyleneglycol (PG). The mixed culture of Pseudomonas sp. 4-5-3 and X. autotrophicus EC 1-2-1 showed better growth and improved degradation than respective single cultures towards EG monomethyl, monoethyl or monobutyl ethers. Intact cells of Pseudomonas sp. 4-5-3 degraded various kinds of monoalkyl ethers, which cannot be assimilated by the strain. Metabolic products were characterized from reaction supernatants of intact cells of Pseudomonas sp. 4-5-3 with EG or DEG monoethyl ethers: they were analyzed by thin-layer chromatography and GC-MS and found to be ethoxyacetic acid and ethoxyglycoxyacetic acid. Also, PG monoalkyl ethers (C1-C4), dipropyleneglycol monoethyl and monomethyl ethers and tripropyleneglycol monomethyl ether were assimilated by polypropyleneglycol-utilizing Corynebacterium sp. 7. PMID:8597556

  1. 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)

  2. Interaction of water with different cellulose ethers: a Raman spectroscopy and environmental scanning electron microscopy study.

    Science.gov (United States)

    Fechner, P M; Wartewig, S; Kiesow, A; Heilmann, A; Kleinebudde, P; Neubert, R H H

    2005-06-01

    Different non-ionic cellulose ethers like methyl cellulose (MC), hydroxypropyl cellulose (HPC) and hydroxypropylmethyl cellulose (HPMC) were investigated. The characterization of the cellulose ethers was carried out by thermogravimetry and sorption/desorption isotherms. Differences in the properties of the cellulose ether films were described by time-dependent contact angle measurements. Changes in molecular structure of the raw materials, gels and films caused by water contact were studied using Raman spectroscopy. Differences between the substitution types and changes due to the gel or film formation were observed. An environmental scanning electron microscopy (ESEM) technique was used to distinguish the morphological behaviour of the cellulose ether films in contact with water. Based on in-situ ESEM experiments, the swelling and drying behaviour of the various stages of cellulose ether films (film-hydrated film-dried film) were quantified by using image analysis. PMID:15969923

  3. Methyltert-butyl Ether (MTBE) Degradation by a Microbial Consortium

    OpenAIRE

    S. B. Mortazavi; A Nikpey; A. Rezaee; H Asilian; A Khavanin; H. Kazemian

    2005-01-01

    Methyl tert-butyl ether (MTBE) is added to reformulated gasoline to meet the 1990 Clean Air Act directives. Widespread use of MTBE in gasoline has resulted in groundwater contamination. Because of its undesirable effects on drinking water and ecologically harmful effects, MTBE removal has become a public health and environmental concern. In this study, we have isolated a mixed bacterial culture which is capable of degrading the MTBE as a sole carbon and energy source. This consortium was deve...

  4. DNA Methylation

    OpenAIRE

    İzmirli, Müzeyyen; Tufan, Turan; Alptekin, Davut

    2012-01-01

    Methylation is a chemical reaction in biological systems for normal genome regulation and development. It is a well known type of epigenetic mechanism. Methylation which regulates gene expression via epigenetic events like gene activation, repression, and chromatin remodelling, consists of two methylation systems. One of these systems is DNA methylation whereas the other is protein (histone) methylation. These systems are associated with some fundamental abnormalities and diseases. This revi...

  5. DNA Methylation

    OpenAIRE

    Muzeyyen Izmirli; Turan Tufan; Davut Alptekin

    2012-01-01

    Methylation is a chemical reaction in biological systems for normal genome regulation and development. It is a well known type of epigenetic mechanism. Methylation which regulates gene expression via epigenetic events like gene activation, repression, and chromatin remodelling, consists of two methylation systems. One of these systems is DNA methylation whereas the other is protein (histone) methylation. These systems are associated with some fundamental abnormalities and diseases. This revie...

  6. STUDY ON SEGMENTED POLYURETHANE WITH MIXED SOFT SEGMENTS OF POLYCHLOROMETHYL METHYL SILOXANE AND POLYTETRAMETHYLENE OXIDE

    Institute of Scientific and Technical Information of China (English)

    JIANG Xiqun; YANG Changzheng; YU Xuehai

    1994-01-01

    Two series of polyurethanes based on mixed polychloromethyl methyl siloxane and polytetramethylene oxide in different weight fractions were synthesized. The phase separation of samples was studied using DSC and dynamic mechanical property analysis. The results showed that the introduction of chloromethyl group into polysiloxane increased its polarity and hence improved the miscibilities with polytetramethylene oxide and polyurethane hard segment.Particularly, in the case of N-methyldiethanolamine extended materials, the surface and tensile properties of these samples can be adjusted by various ratios of two soft segments.

  7. Ether and Relativity

    CERN Document Server

    Farhoudi, Mehrdad

    2015-01-01

    We consider one of the fundamental debates in performing the relativity theory, namely, the ether and the relativity points of view, in a way to aid the learning of the subjects. In addition, we present our views and prospects while describing the issues that being accessible to many physicists and allowing broader views. Also, we very briefly review the two almost recent observations of the Webb redshift and the ultra high-energy cosmic rays, and the modified relativity models that have been presented to justify them, wherein we express that these justifications have not been performed via a single model with a single mechanism.

  8. Ether and Relativity

    Science.gov (United States)

    Farhoudi, Mehrdad; Yousefian, Maysam

    2016-05-01

    We consider one of the fundamental debates in performing the relativity theory, namely, the ether and the relativity points of view, in a way to aid the learning of the subjects. In addition, we present our views and prospects while describing the issues that being accessible to many physicists and allowing broader views. Also, we very briefly review the two almost recent observations of the Webb redshift and the ultra high energy cosmic rays, and the modified relativity models that have been presented to justify them, wherein we express that these justifications have not been performed via a single model with a single mechanism.

  9. Separação de fases induzida por meio de reação química no sistema éter diglicidílico do bisfenol A e piperidina com poli(metacrilato de metila Phase separation induced by chemical reaction in the system of diglycidyl ether of bisphenol A and piperidine with poly(methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Filiberto González Garcia

    2003-12-01

    Full Text Available O comportamento da separação de fases e da gelificação do sistema epoxídico, constituído pelo éter diglicidílico do bisfenol A (DGEBA e a piperidina, modificado com poli(metacrilato de metila (PMMA, foi estudado na faixa de temperatura de 60 °C - 120 °C. A concentração de PMMA e a temperatura de cura causam mudanças significativas na morfologia gerada. A massa molecular de PMMA provoca ligeiras mudanças para a observação da separação de fases e não afeta a velocidade da reação. O sistema modificado com PMMA mostra o efeito de retardação cinético e a velocidade de separação de fases é maior que a velocidade de polimerização.The phase separation and gelification behavior of epoxy system based on diglycidyl ether of bisphenol-A (DGEBA and piperidine modified with poly(methyl methacrylate (PMMA were studied in the range between 60 °C and 120 °C. The morphology is influenced by the PMMA content in the blend and also by the cure temperature. The molecular weight of PMMA provokes slight changes on cloud point and does not affect the reaction rate. The systems modified by PMMA exhibited kinetic retardation effect but the cloud point rate was higher than the polymerization rate.

  10. Determination of Methyl Tert-Butyl Ether in Surface Water of Huizhou City Using the Method of SPME-Headspace-GC-MS-SIM%固相微萃取-GC-MS-SIM法监测惠州市地表水中MTBE的污染状况

    Institute of Scientific and Technical Information of China (English)

    王希在; 奉夏平; 闻环

    2009-01-01

    采用固相微萃取(SPME)-顶空采样-气相色谱-质谱联用选择离子检测法(GC-MS-SIM)测定水中微量的甲基叔丁基醚.最优化实验条件为:使用75μm Carboxen/PDMS固相微萃取纤维,30℃搅拌条件下,加入20%氯化钠进行盐析.检出限为0.05μg/L,相对标准偏差为2.75%(n=8),重现性较好,样品的加标回收率在82%-120%之间.对惠州市市区地表水中MTBE的污染状况进行了监测,结果表明惠州市汽油油罐附近地表水中MTBE含量未超过美国环保局(EPA)规定最低限,居民区地表水中MTBE含量未检出,符合环保和健康要求.%Trace methyl tert-butyl ether (MTBE) in surface water was determined using the method of solid-phase micro extraction (SPME)-headspaee-GC-MS-SIM. The detection limit was 0.05μg/L, and the relative standard deviation was 2.75 %. The recoveries with standard addition were 82%-120%. We have studied the MTBE polution problem in surface water of Huizhou. The result suggested that MTBE content in surface water of Huizhou was not beyond EPA standard limits.

  11. Microwave Spectrum of the Ethylmethyl Ether Molecule

    Directory of Open Access Journals (Sweden)

    Kojiro Takagi

    2003-01-01

    Full Text Available We have observed rotational transitions of ethylmethyl ether (CH3CH2OCH3 in the 24-110 GHz frequency range. We newly assigned the transitions of four Q-branch series for J=1-38 with Ka=0-5 and six R-branch series of b-type transitions for J=7-37 with Ka=0-3. All these assigned transitions were observed to be split into two or four components due to the internal rotations of the methyl groups. We analyzed the averaged frequencies of the split components on the basis of the Watson A-reduced Hamiltonian, neglecting the effect of the internal rotations. A total of 122 transitions were fitted to eight molecular parameters to a 1s standard deviation of 24 kHz. The parameters A, B, C and DJ were improved, and DJK, Dk, dJ and dK were determined for the first time.

  12. Development of specialty chemicals from dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Tartamella, T.L.; Lee, S. [Univ. of Akron, OH (United States). Dept. of Chemical Engineering

    1996-12-31

    Dimethyl ether (DME) may be efficiently produced from coal-bases syngas in a high pressure, mechanically agitated slurry reactor. DME synthesis occurs in the liquid phase using a dual catalyst. By operating in a dual catalyst mode, DME may be converted from in-situ produced methanol resulting in higher methyl productivities and syngas conversions over methanol conversion alone. The feasibility of utilizing DME as a building block for more valuable specialty chemicals has been examined. A wide variety of petrochemicals may be produced from DME including light olefins, gasoline range hydrocarbons, oxygenates, and glycol precursors. These chemicals represent an important part of petroleum industries inventory of fine chemicals. Carbonylation, hydrocarbonylation, and oxidative dimerization are but a few of the reactions in which DME may undergo conversion. DME provides an additional route for the production of industrially important petrochemicals.

  13. Synthesis and tentative identification of novel polybrominated diphenyl ether metabolites in human blood.

    Science.gov (United States)

    Rydén, Andreas; Nestor, Gustav; Jakobsson, Kristina; Marsh, Göran

    2012-08-01

    Hydroxylated polybrominated diphenyl ethers (OH-PDBEs) are exogenous, bioactive compounds that originate, to a large extent, from anthropogenic activities, although they are also naturally produced in the environment. In the present study nine new authentic OH-PBDE reference standards and their corresponding methyl ether derivatives (MeO-PBDEs) were synthesised and characterised by NMR spectroscopy and mass spectrometry. Seven of the authentic reference standards prepared were thereafter tentatively identified in a pooled human blood sample. The tentatively identified OH-PBDEs were 3-hydroxy-2,2',4,4',6-pentabromodiphenyl ether, 3'-hydroxy-2,2',4,4',6-pentabromodiphenyl ether, 3-hydroxy-2,2',4,4',5-pentabromodiphenyl ether, 3-hydroxy-2,2',4,4',5,6'-hexabromodiphenyl ether, 3'-hydroxy-2,2',4,4',5,6'-hexabromodiphenyl ether, 3-hydroxy-2,2',4,4',5,5'-hexabromodiphenyl ether and 4-hydroxy-2,2',3,4',5,5',6-heptabromodiphenyl ether. An additional seven OH-PBDEs were tentatively identified in the pooled human blood sample, of which one OH-PBDE, 4'-hydroxy-2,2',4,5,5'-pentabromodiphenyl ether, has not been identified in human blood before. The identification was performed using gas chromatography-mass spectrometry (GC-MS) recording the bromine ions m/z 79, 81. The tentative identification was supported by the peaks relative retention times (RRTs) compared to authentic references on two GC columns of different polarities for the hexa-, and heptabrominated OH-PBDEs, and three different GC columns for the pentabrominated OH-PBDEs. The OH-PBDE congeners most likely originate from human metabolism of a flame retardant, i.e. polybrominated diphenyl ethers (PBDEs), due to the relatively high concentrations of PBDEs in the same human blood sample and the fact that these PBDEs could form the tentatively identified OH-PBDEs via metabolic direct hydroxylation or via 1,2-shift. PMID:22572169

  14. 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)

  15. Direct Dimethyl Ether Synthesis

    Institute of Scientific and Technical Information of China (English)

    Takashi Ogawa; Norio Inoue; Tutomu Shikada; Yotaro Ohno

    2003-01-01

    Dimethyl ether (DME) is a clean and economical alternative fuel which can be produced from natural gas through synthesis gas. The properties of DME are very similar to those of LP gas. DME can be used for various fields as a fuel such as power generation, transportation, home heating and cooking,etc. It contains no sulfur or nitrogen. It is not corrosive to any metal and not harmful to human body. An innovative process of direct synthesis of DME from synthesis gas has been developed. Newly developed catalyst in a slurry phase reactor gave a high conversion and high selectivity of DME production. One and half year pilot scale plant (5 tons per day) testing, which was supported by METI, had successfully finished with about 400 tons DME production.

  16. Synthesis and fungicidal activities of novel benzothiophene-substituted oxime ether strobilurins.

    Science.gov (United States)

    Tu, Song; Xie, Ya-Qiang; Gui, Si-Zhe; Ye, Li-Yi; Huang, Zi-Long; Huang, Yi-Bing; Che, Li-Ming

    2014-05-01

    Twenty-one novel benzothiophene-substituted oxime ether strobilurins, which employed a benzothiophene group to stabilise the E-styryl group in Enoxastrobin (an unsaturated oxime strobilurin fungicide developed by Shenyang Research Institute of Chemical Industry, China) were designed and synthesised. The biological assay indicated that most compounds exhibited good or excellent fungicidal activities, especially against Colletotrichum lagenarium and Puccinia sorghi Schw. In addition, methyl 3-methoxypropenoate oxime ethers and N-methoxy-carbamic acid methyl esters exhibited good in vivo fungicidal activities against Erysiphe graminis, Colletotrichum lagenarium and Puccinia sorghi Schw. under the tested concentrations. Notably, (E,E)-methyl 3-methoxy-2-(2-((((6-chloro-1-(1H-benzo[b]thien-2-yl)ethylidene)amino)oxy)methyl)phenyl)propenoate (5E) exhibited more potent in vivo fungicidal activities against nearly all of the tested fungi at a concentration of 0.39 mg/L compared to Enoxastrobin. PMID:24717155

  17. Processed Lignin as a Byproduct of the Generation of 5-(Chloromethyl)furfural from Biomass: A Promising New Mesoporous Material.

    Science.gov (United States)

    Budarin, Vitaliy L; Clark, James H; Henschen, Jonatan; Farmer, Thomas J; Macquarrie, Duncan J; Mascal, Mark; Nagaraja, Gundibasappa K; Petchey, Tabitha H M

    2015-12-21

    The lignin by-product of the conversion of lignocellulosic biomass to 5-(chloromethyl)furfural (CMF) has been characterised by thermogravimetric analysis, N2 physisorption porosimetry, attenuated internal reflectance IR spectroscopy, elemental analysis and solid-state NMR spectroscopy. The lignin (LCMF) has a moderate level of mesoporosity before thermal treatment and a surface area of 63 m(2)  g(-1) , which increases dramatically on pyrolysis at temperatures above 400 °C. An assessment of the functionality and textural properties of the material was achieved by analysing LCMF treated thermally over a range of pyrolysis temperatures. Samples were sulfonated to test their potential as heterogeneous acid catalysts in the esterification of levulinic acid. It was shown that unpyrolysed catalysts gave the highest ester yields of up to 93 %. To the best of our knowledge, this is the first example of mesoporous lignin with an appreciable surface area that is produced directly from a bio-refinery process and with further textural modification of the material demonstrated. PMID:26601798

  18. 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.

  19. Fatty Acid Methyl Esters as Biosolvents of Epoxy Resins: A Physicochemical Study

    OpenAIRE

    Medina-González, Yaocihuatl; De Caro, Pascale; Thiebaud-Roux, Sophie; Lacaze-Dufaure, Corinne

    2007-01-01

    The C8 to C18 fatty acid methyl esters (FAME) have been compared as solvents for two epoxy resin pre-polymers, bisphenol A diglycidyl ether (DGEBA) and triglycidyl paminophenol ether (TGPA). It was found that the solubilization limits vary according to the ester and that methyl caprylate is the best solvent of both resins. To explain these solubility performances, physical and chemical properties of FAME were studied, such as the Hansen parameters, viscosity, binary diffusion coefficient and ...

  20. Kinetic Isotope Effects in the Reduction of Methyl Iodide

    DEFF Research Database (Denmark)

    Holm, Torkil

    1999-01-01

    a-Deuterium kinetic isotope effects (KIE's) have been determined for the reaction of methyl iodide with a series of reducing agents. Reagents which transfer hydride ion in an SN2 reaction show small inverse or small normal KIE's. Reagents which transfer an electron to methyl iodide to produce...... methyl radical show large normal KIE's up to 20 % per a-D. Large KIE's were found for the reaction of methyl iodide with sodium, for Pd-catalyzed reaction of methyl iodide with hydrogen, for ET at a platinum cathode, for ET from benzophenone ketyl or from sodium naphthalenide, for iron catalyzed ET from...... 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...

  1. 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. PMID:16664206

  2. 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

  3. Selective and efficient synthesis of ethanol from dimethyl ether and syngas

    DEFF Research Database (Denmark)

    Rasmussen, Dominik Bjørn

    important role as a gasoline additive or substitute and a catalytic process has been demonstrated, in which dimethyl ether (DME) produced from synthesis gas is converted to methyl acetate (MA), which is subsequently converted to EtOH and methanol (MeOH). MeOH can afterwards be easily converted to DME, using...... synthesis and form a firm foundation for the future studies....

  4. Synthesis and properties of segmented copolymers of polyphenylene ether and tetra-amide units

    NARCIS (Netherlands)

    Krijgsman, Josien; Feijen, Jan; Gaymans, Reinoud J.

    2003-01-01

    Copolymers of telechelic poly(2,6-dimethyl-1,4-phenylene ether) segments with terephthalic methyl ester endgroups (PPE-2T, 3100 g/mol), uniform crystallizable tetra-amide units based on nylon-6,T (T6T6T, 13 wt%) and dodecanediol (C12) as an extender were made via a polycondensation reaction. The PPE

  5. SYNTHESIS AND CRYSTALLIZATION BEHAVIOR OF POLY(ETHER ETHER KETONE ETHER KETONE) (PEEKEK)

    Institute of Scientific and Technical Information of China (English)

    Zhao-bin Qiu; Zhi-shen Mo; Ying-ning Yu; Hong-fang Zhang; Xian-hong Wang

    2000-01-01

    In this paper, the synthesis and crystallization behavior of poly(ether ether ketone ether ketone) (PEEKEK) are reported. PEEKEK was prepared from 4,4'-bis(p-fluorobenzoyl) diphenyl ether (4,4'-FBDE) and hydroquinone along the nucleophilic substitution route. The thermal properties were investigated by using DSC and TGA. The crystallization behavior of PEEKEK under several conditions, i.e., crystallization from the molten state (melt crystallization), crystallization from a quenched sample (cold crystallization) and crystallization induced by exposing glassy sample to methylene chloride (solvent-induced crystallization) has also been investigated. The results show that crystallization of PEEKEK could be induced by the above methods, and no polymorphism was found. The differences in the crystallization of PEEKEK induced by the above methods are seen in their degree of crystallinity.

  6. Low-Temperature Thermodynamics of Fatty Acid Methyl Ethers (FAME)

    Science.gov (United States)

    The most common form of biodiesel is made by transesterification reaction of vegetable oil or fat with methanol. Although biodiesel is attractive as an alternative diesel fuel or extender, depending on its feedstock it may be very susceptible to cause start up and operability problems during cold w...

  7. Methyl Iodide

    Science.gov (United States)

    Methyl iodide (MeI, iodomethane, CH3I) was reported as a potential alternative to the stratospheric ozone-depleting fumigant methyl bromide (MeBr) in the mid-1990s (Sims et al., 1995; Ohr et al., 1996). It has since received significant research attention to determine its environmental fate and tran...

  8. Formulating liquid ethers for microtubular SOFCs

    Science.gov (United States)

    Kendall, Kevin; Slinn, Matthew; Preece, John

    One of the key problems of applying solid oxide fuel cells (SOFCs) in transportation is that conventional fuels like kerosene and diesel do not operate directly in SOFCs without prereforming to hydrogen and carbon monoxide which can be handled by the nickel cermet anode. SOFCs can internally reform certain hydrocarbon molecules such as methanol and methane. However, other liquid fuels usable in petrol or diesel internal combustion engines (ICEs) have not easily been reformable directly on the anode. This paper describes a search for liquid fuels which can be mixed with petrol or diesel and also injected directly into an SOFC without destroying the nickel anode. When fuel molecules such as octane are injected onto the conventional nickel/yttria stabilised zirconia (Ni/YSZ) SOFC fuel electrode, the anode rapidly becomes blocked by carbon deposition and the cell power drops to near zero in minutes. This degeneration of the anode can be inhibited by injection of air or water into the anode or by some upstream reforming just before entry to the SOFC. Some smaller molecules such as methane, methanol and methanoic acid produce a slight tendency to carbon deposition but not sufficient to prevent long term operation. In this project we have investigated a large number of molecules and now found that some liquid ethers do not significantly damage the anode when directly injected. These molecules and formulations with other components have been evaluated in this study. The theory put forward in this paper is that carbon-carbon bonds in the fuel are the main reason for anode damage. By testing a number of fuels without such bonds, particularly liquid ethers such as methyl formate and dimethoxy methane, it has been shown that SOFCs can run without substantial carbon formation. The proposal is that conventional fuels can be doped with these molecules to allow hybrid operation of an ICE/SOFC device.

  9. Equilibrium and kinetic studies on ligand substitution reactions of chloromethyl(aquo)cobaloxime with aromatic and aliphatic N-donor ligands

    Indian Academy of Sciences (India)

    D Sudarshan Reddy; S Satyanarayana

    2003-06-01

    Equilibria and kinetics of the reactions of chloromethyl(aquo)cobaloxime with histamine, histidine, glycine and ethyl glycine ester were studied as a function of pH at 25°C, 1.0 M ionic strength (KCl) by spectrophotometric techniques. Comparison of equilibrium constants and rate constants tells that the order is Hisdn > Hiamn > Gly > EtGlyest. The rate of substitution of H2O varies with the p of the incoming ligand and nucleophilic participation of the ligand in the transition state. The rate constants and equilibrium constants are correlated to the hardness and softness of the ligands and the Co(III) of cobaloxime.

  10. The unsaturated simple ethers of glycerin

    International Nuclear Information System (INIS)

    To the unsaturated simple ethers of glycerin related allyl, vinyl ethers, which can be mono-, di- and three-substitutes. Besides there are known compounds, which contain simultaneously saturate and unsaturated radicals in molecule

  11. Alkyl aryl ethers in lignite solubilization 1. Study of the process

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1984-10-01

    The chemistry of solubilization of a lignite has been investigated with anisole, 3-methyl anisole and 1,3dimethoxybenzene catalysed by SbCl/sub 3/, ZnCl/sub 2/, AlCl/sub 3/ and BF/sub 3/ as boron trifluoride etherate, at atmospheric pressure and temperatures <220/sup 0/C. 60% of lignite was solubilized in a toluene-ethanol azeotropic mixture. During the process, the solvent is incorporated as an alkylated substratum. The yield increased with activity of the aromatic ether ring and catalyst acidity.

  12. Alkyl aryl ethers in lignite solubilization. 1. Study of the process

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1984-10-01

    The chemistry of solubilization of a lignite has been investigated with anisole, 3-methyl anisole and 13-dimethoxybenzene catalysed by SbCl/sub 3/, ZnCl/sub 2/, AlCl/sub 3/ and BF/sub 3/ as boron trifluoride etherate, at atmospheric pressure and temperatures <220 C. 60% of lignite was solubilized in a toluene-ethanol azeotropic mixture. During the process, the solvent is incorporated as an alkylated substratum. The yield increased with activity of the aromatic ether ring and catalyst acidity. 14 references.

  13. Long term studies on the anaerobic biodegradability of MTBE and other gasoline ethers

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

    2009-01-01

    Anaerobic biodegradation of methyl tert-butyl ether (MTBE) using electron acceptors such as nitrate, Fe(III), sulfate and bicarbonate, may be more cost effective and feasible compared to aerobic treatment methods, for dealing with the MTBE problem. Currently. there are a few reports in the...... to investigate the anaerobic biodegradability of MTBE and other gasoline ethers. Inoculums collected from various environments were used, along with different electron acceptors. Only one set of the batch experiments showed a 30-60% conversion of MTBE to tert-butyl alcohol under Fe...

  14. DNA Methylation

    OpenAIRE

    Alokail, Majed S.; Alenad, Amal M

    2015-01-01

    The DNA of E. coli contains 19,120 6-methyladenines and 12,045 5-methylcytosines in addition to the four regular bases and these are formed by the postreplicative action of three DNA methyltransferases. The majority of the methylated bases are formed by the Dam and Dcm methyltransferases encoded by the dam (DNA adenine methyltransferase) and dcm (DNA cytosine methyltransferase) genes. Although not essential, Dam methylation is important for strand discrimination during repair of replication e...

  15. The simple ethers of glycerin

    International Nuclear Information System (INIS)

    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

  16. Degradace methyl tert-butyl etheru (MTBE) v bioreaktoru.

    Czech Academy of Sciences Publication Activity Database

    Lehnert, Radek; Gavlasová, Pavla; Kuncová, Gabriela; Bolyó, Juraj

    Bratislava: -, 2007, s. 225-226. [Zjazd chemikov /59./. Tatranské Matliare, Vysoké Tatry (SK), 02.09.2007-06.09.2007] R&D Projects: GA ČR(CZ) GA104/05/2637 Institutional research plan: CEZ:AV0Z40720504 Keywords : biodegradation * methyl terc-butyl ether (MTBE) Subject RIV: CE - Biochemistry

  17. Nucleophilic Participation in the Solvolyses of (Arylthio)methyl Chlorides and Derivatives: Application of Simple and Extended Forms of the Grunwald-Winstein Equations

    OpenAIRE

    Kevill, Dennis N.; Park, Young Hoon; Park, Byoung-Chun; D’Souza, Malcolm J.

    2012-01-01

    The specific rates of solvolysis of chloromethyl phenyl sulfide [(phenylthio)methyl chloride] and its p-chloro-derivative have been determined at 0.0 °C in a wide range of hydroxylic solvents, including several containing a fluroalcohol. Treatment in terms of a two-term Grunwald-Winstein equation, incorporating terms based on solvent ionizing power (YCl) and solvent nucleophilicity (NT) suggest a mechanism similar to that for the solvolyses of tert-butyl chloride, involving in the rate-determ...

  18. Synthesis of bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine oxide – a tailor-made photoinitiator for dental adhesives

    Directory of Open Access Journals (Sweden)

    Norbert Moszner

    2010-03-01

    Full Text Available Because of the poor solubility of the commercially available bisacylphosphine oxides in dental acidic aqueous primer formulations, bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine oxide (WBAPO was synthesized starting from 3-(chloromethyl-2,4,6-trimethylbenzoic acid by the dichlorophosphine route. The substituent was introduced by etherification with 2-(allyloxyethanol. In the second step, 3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoic acid was chlorinated. The formed acid chloride showed an unexpected low thermal stability. Its thermal rearrangement at 180 °C resulted in a fast formation of 3-(chloromethyl-2,4,6-trimethylbenzoic acid 2-(allyloxyethyl ester. In the third step, the acid chloride was reacted with phenylphosphine dilithium with the formation of bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine, which was oxidized to WBAPO. The structure of WBAPO was confirmed by 1H NMR, 13C NMR, 31P NMR, and IR spectroscopy, as well as elemental analysis. WBAPO, a yellow liquid, possesses improved solubility in polar solvents and shows UV–vis absorption, and a high photoreactivity comparable with the commercially available bisacylphosphine oxides. A sufficient storage stability was found in dental acidic aqueous primer formulations.

  19. Synthesis of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide - a tailor-made photoinitiator for dental adhesives.

    Science.gov (United States)

    Moszner, Norbert; Lamparth, Iris; Angermann, Jörg; Fischer, Urs Karl; Zeuner, Frank; Bock, Thorsten; Liska, Robert; Rheinberger, Volker

    2010-01-01

    Because of the poor solubility of the commercially available bisacylphosphine oxides in dental acidic aqueous primer formulations, bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide (WBAPO) was synthesized starting from 3-(chloromethyl)-2,4,6-trimethylbenzoic acid by the dichlorophosphine route. The substituent was introduced by etherification with 2-(allyloxy)ethanol. In the second step, 3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoic acid was chlorinated. The formed acid chloride showed an unexpected low thermal stability. Its thermal rearrangement at 180 ° C resulted in a fast formation of 3-(chloromethyl)-2,4,6-trimethylbenzoic acid 2-(allyloxy)ethyl ester. In the third step, the acid chloride was reacted with phenylphosphine dilithium with the formation of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine, which was oxidized to WBAPO. The structure of WBAPO was confirmed by ¹H NMR, ¹³C NMR, ³¹P NMR, and IR spectroscopy, as well as elemental analysis. WBAPO, a yellow liquid, possesses improved solubility in polar solvents and shows UV-vis absorption, and a high photoreactivity comparable with the commercially available bisacylphosphine oxides. A sufficient storage stability was found in dental acidic aqueous primer formulations. PMID:20502649

  20. A new alternative to expandable pedicle screws: Expandable poly-ether-ether-ketone shell.

    Science.gov (United States)

    Demir, Teyfik

    2015-05-01

    Screw pullout is a very common problem in the fixation of sacrum with pedicle screws. The principal cause of this problem is that the cyclic micro motions in the fixation of sacrum are higher than the other regions of the vertebrae that limit the osteo-integration between bone and screw. In addition to that, the bone quality is very poor at sacrum region. This study investigated a possible solution to the pullout problem without the expandable screws' handicaps. Newly designed poly-ether-ether-ketone expandable shell and classical pedicle screws were biomechanically compared. Torsion test, pullout tests, fatigue tests, flexion/extension moment test, axial gripping capacity tests and torsional gripping capacity tests were conducted in accordance with ASTM F543, F1798 and F1717. Standard polyurethane foam and calf vertebrae were used as embedding medium for pullout tests. Classical pedicle screw pullout load on polyurethane foam was 564.8 N compared to the failure load for calf vertebrae's 1264 N. Under the same test conditions, expandable poly-ether-ether-ketone shell system's pullout loads from polyurethane foam and calf vertebrae were 1196.3 and 1890 N, respectively. The pullout values for expandable poly-ether-ether-ketone shell were 33% and 53% higher than classical pedicle screw on polyurethane foam and calf vertebrae, respectively. The expandable poly-ether-ether-ketone shell exhibited endurance on its 90% of yield load. Contrary to poly-ether-ether-ketone shell, classical pedicle screw exhibited endurance on 70% of its yield load. Expandable poly-ether-ether-ketone shell exhibited much higher pullout performance than classical pedicle screw. Fatigue performance of expandable poly-ether-ether-ketone shell is also higher than classical pedicle screw due to damping the micro motion capacity of the poly-ether-ether-ketone. Expandable poly-ether-ether-ketone shell is a safe alternative to all other expandable pedicle screw systems on mechanical perspective

  1. DNA methylation

    DEFF Research Database (Denmark)

    Williams, Kristine; Christensen, Jesper; Helin, Kristian

    2012-01-01

    DNA methylation is involved in key cellular processes, including X-chromosome inactivation, imprinting and transcriptional silencing of specific genes and repetitive elements. DNA methylation patterns are frequently perturbed in human diseases such as imprinting disorders and cancer. The recent...... discovery that the three members of the TET protein family can convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) has provided a potential mechanism leading to DNA demethylation. Moreover, the demonstration that TET2 is frequently mutated in haematopoietic tumours suggests that the TET...... proteins are important regulators of cellular identity. Here, we review the current knowledge regarding the function of the TET proteins, and discuss various mechanisms by which they contribute to transcriptional control. We propose that the TET proteins have an important role in regulating DNA methylation...

  2. Ether symmetry unification theory (ESU)

    International Nuclear Information System (INIS)

    The ether symmetry unification (ESU) theory postulates a mechanism that accounts for the formation of the universe as well as the formation of the original mass particles following the big bang. The essential role of the medium-vacuum of the theory of prerelativity is explained. The ultra-high energy particles described in the Ether Symmetry Unification Theory are compared with high energy magnetic monopoles described by Supersymmetry. Phase transitions of high energy events to low energy events and the associated media-vacua involved, postulated by the ESU, are then compared to the low energy events of the standard model within the critical phases of the first two seconds of quantum field theory's time line

  3. Analysis of ethereal extracts of wines and other alcoholic beverages by high-performance liquid chromatography with microbore columns.

    Science.gov (United States)

    Cartoni, G P; Coccioli, F; Spagnoli, M

    1997-10-10

    The ethereal extracts of wines, beer and vermouth were analysed by high-performance liquid chromatography. The following three characteristic peaks were first identified using GC-MS and then quantitatively determined: 5-hydroxy-methyl-2-furaldehyde, 2-(4-hydroxyphenyl)ethanol and 3-(2-hydroxyethyl)indole. PMID:9440923

  4. Síntese e caracterização de copolímeros de estireno e divinilbenzeno clorometilados Synthesis and characterization of chloromethylated styrene-divinylbenzene copolymers

    Directory of Open Access Journals (Sweden)

    Viviane G. Teixeira

    2004-01-01

    Full Text Available A reação de clorometilação de copolímeros de estireno e divinilbenzeno (S-DVB em presença de HCl, formaldeído e cloreto de zinco foi estudada em meios aquoso e orgânico. O copolímero S-DVB foi, primeiramente, sintetizado por polimerização em suspensão e caracterizado quanto às suas propriedades porosas. Em meio aquoso, o copolímero foi clorometilado borbulhando-se HCl na mistura de solução aquosa de formaldeído a 37% (formalina 37% e solução aquosa de cloreto de zinco (catalisador. Em meio orgânico (1,2-dicloroetano, foram usados HCl (borbulhado na solução reacional, paraformaldeído e cloreto de zinco sólido. A presença de grupos clorometila foi identificada por espectroscopia na região do infravermelho e o teor desses grupos foi determinado por titulação potenciométrica dos íons cloreto, liberados após a reação de quaternização com piridina. A reação em meio aquoso originou copolímeros com baixos graus de clorometilação, mesmo sob condições drásticas (uso do catalisador sólido e ácido clorídrico concentrado como meio reacional. Em meio orgânico, devido à maior estabilidade do eletrófilo, foram originados copolímeros com teores mais altos de grupos clorometila. Foi estudada a influência dos parâmetros reacionais sobre o grau de clorometilação dos copolímeros em meio orgânico. A temperatura e a razão copolímero/catalisador foram parâmetros determinantes do grau de clorometilação obtido.Cloromethylation of styrene-divinylbenzene copolymer (S-DVB in presence of hydrogen chloride, formaldehyde and zinc chloride was studied in aqueous and organic media. S-DVB was first synthesized by suspension polymerization and its porosity was characterized. In aqueous medium, S-DVB was chloromethylated by using a mixture of hydrogen chloride, aqueous formaldehyde solution (formalin 37% and aqueous zinc chloride solution as catalyst. In organic medium (1,2-dichloroethane, a mixture of hydrogen chloride

  5. Review of glycol ether and glycol ether ester solvents used in the coating industry.

    OpenAIRE

    Smith, R.L.

    1984-01-01

    Ethylene oxide-based glycol ether and glycol ether ester solvents have been used in the coatings industry for the past fifty years. Because of their excellent performance properties (evaporation rate, blush resistance, flow-out and leveling properties, solubility for coating resins, solvent activity, mild odor, good coupling ability, good solvent release) a complete line of ethylene oxide-based solvents of various molecular weights has been developed. These glycol ether and glycol ether ester...

  6. A green light emitting polymer in a PMMA matrix: oligo(azomethine-ether) with benzothiazole moieties

    OpenAIRE

    YILDIRIM, Mehmet; KAYA, İsmet

    2015-01-01

    This study aimed to synthesize an oligo(azomethine-ether) with benzothiazole moiety in organic medium by means of chemical oxidative polycondensation (OP). Optical properties were examined by photoluminescence (PL) and UV-Vis measurements both in solutions and solid film involved a poly (methyl methacrylate) (PMMA) matrix. Oligomer film in the PMMA matrix emitted a fine green light with a fluorescence quantum yield (QY) of 3.30%. Spectral and thermal observations showed a high rate of C...

  7. Flow-Induced Crystallization of Poly(ether ether ketone)

    Science.gov (United States)

    Nazari, Behzad; Rhoades, Alicyn; Colby, Ralph

    The effects of an interval of shear above the melting temperature Tm on subsequent isothermal crystallization below Tm is reported for the premier engineering thermoplastic, poly(ether ether ketone) (PEEK). The effect of shear on the crystallization rate of PEEK is investigated by means of rheological techniques and differential scanning calorimetry (DSC) under a protocol of imposing shear in a rotational cone and plate rheometer and monitoring crystallization after quenching. The rate of crystallization at 320 °C was not affected by shear for shear rates <7 s-1 at 350 °C, whereas intervals of adequate shear at higher shear rates prior to the quench to 320 °C accelerated crystallization significantly. As the duration of the interval of shear above 7 s-1 is increased, the crystallization time decreases but at each shear rate eventually saturates once the applied specific work exceeds ~120 MPa. The annealing of the flow-induced precursors was also investigated. The nuclei were fairly persistent at temperatures close to 350 °C, however very unstable at temperatures above 375 °C. This suggests that the nanostructures formed under shear might be akin to crystalline lamellae of greater thickness, compared to quiescently crystallized lamellae.

  8. Thermochemical biorefinery based on dimethyl ether as intermediate: Technoeconomic assessment

    International Nuclear Information System (INIS)

    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, H2, 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 MWth 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.

  9. 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.

  10. Atmospheric lifetimes of selected fluorinated ether compounds

    DEFF Research Database (Denmark)

    Heathfield, A.E.; Anastasi, C.; Pagsberg, Palle Bjørn;

    1998-01-01

    Atmospheric lifetimes have been estimated for a selection of ethers, the latter representing a class of compounds being considered as replacements for chlorofluorocarbons. The estimates are based on laboratory measurements of rate constants for the reaction of the OH radical with the ethers, and ...

  11. Unitary information ether and its possible applications

    International Nuclear Information System (INIS)

    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.)

  12. The Microwave Spectrum of Partially Deuterated Species of Dimethyl Ether

    Science.gov (United States)

    Lauvergnat, D.; Margulès, L.; Motiyenko, R. A.; Guillemin, J.-C.; Coudert, L. H.

    2011-06-01

    Dimethyl ether is a molecule of astrophysical interest spectroscopically well characterized. It is one of the simplest molecules with two methyl groups undergoing large amplitude internal rotations. Due to deuterium enrichment in the interstellar medium, one can reasonably expect that partially deuterated species of dimethyl ether might be detected. However, there are no spectroscopic results about the microwave spectrum of such species. A theoretical calculation of the rotation-torsion energy levels of the partially deuterated species of dimethyl ether has been undertaken aided by ab initio calculations. The approach accounts for the complicated torsion-rotation interactions displayed by this molecule and for the fact that deuteration leads to changes of the bidimensional internal rotation effective potential energy surface. Due to zero-point energy contributions from the 19 small amplitude vibrational modes, this surface no longer displays G36 symmetry. Rotation-torsion energy levels are computed treating the two angles of internal rotation as active coordinates and evaluating Hamiltonian matrix elements with the help of Gaussian quadrature. It is hoped that the present results will allow us to understand the microwave spectrum of the mono deuterated species CH_2DOCH_3 which has been recorded in Lille with the new sub millimeter wave spectrometer (150--950 GHz) based on harmonic generation of solid-state sources. [2] Snyder, Buhl, and Schwartz, Astrophys. J. Letters 191 (1974) L79. [3] Endres, Drouin, Pearson, Müller, Lewen, Schlemmer, and Giesen, A&A 504 (2009) 635. [4] Solomon and Woolf, Astrophys. J. Letters 180 (1973) L89. [5] Lauvergnat and Nauts, J. Chem. Phys. 116 (2002) 8560; and Light and Bačić, J. Chem. Phys. 87 (1987) 4008.

  13. CATALYSTS FOR HIGH CETANE ETHERS AS DIESEL FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Richard G. Herman; Heock-Hoi Kwon; James G. C. Shen; Qisheng Ma; Robert A. Hunsicker; Andrew P. Butler; Scott J. Bollinger

    2003-03-01

    A tungstena-zirconia (WZ) catalyst has been investigated for coupling methanol and isobutanol to unsymmetrical ethers, i.e. methyl isobutyl ether (MIBE) and compared with earlier studied sulfated-zirconia (SZ) and Nafion-H catalysts. In all cases, the ether synthesis mechanism is a dual site S{sub N}2 process involving competitive adsorption of reactants on proximal acid sites. At low reaction temperatures, methylisobutylether (MIBE) is the predominant product. However, at temperatures >135 C the WZ catalyst is very good for dehydration of isobutanol to isobutene. The surface acid sites of the WZ catalyst and a Nafion-H catalyst were diagnosed by high resolution X-ray photoelectron spectroscopy (XPS) of N 1s shifts after adsorption of amines. Using pyridine, ethylenediamine, and triethylamine, it is shown that WZ has heterogeneous strong Broensted acid sites. Theoretical study located the transition state of the alcohol coupling reaction on proximal Broensted acid sites and accounted well for XPS core-level shifts upon surface acid-base interactions. While computations have not been carried out with WZ, it is shown that the SZ catalyst is a slightly stronger acid than CF{sub 3}SO{sub 3}H (a model for Nafion-H) by 1.3-1.4 kcal/mol. A novel sulfated zirconia catalyst having proximal strong Broensted acid sites was synthesized and shown to have significantly enhanced activity and high selectivity in producing MIBE or isobutene from methanol/isobutanol mixtures. The catalyst was prepared by anchoring 1,2-ethanediol bis(hydrogen sulfate) salt precursor onto zirconium hydroxide, followed by calcination to remove the -(CH{sub 2}CH{sub 2})- bridging residues.

  14. Methyl gallate

    Directory of Open Access Journals (Sweden)

    Silvina Pagola

    2009-02-01

    Full Text Available The crystal structure of the title compound (systematic name: methyl 3,4,5-trihydroxybenzoate, C8H8O5, is composed of essentially planar molecules [maximum departures from the mean carbon and oxygen skeleton plane of 0.0348 (10 Å]. The H atoms of the three hydroxyl groups, which function as hydrogen-bond donors and acceptors simultaneously, are oriented in the same direction around the aromatic ring. In addition to two intramolecular hydrogen bonds, each molecule is hydrogen bonded to six others, creating a three-dimensional hydrogen-bonded network.

  15. Methyl gallate.

    Science.gov (United States)

    Bebout, Deborah; Pagola, Silvina

    2009-01-01

    THE CRYSTAL STRUCTURE OF THE TITLE COMPOUND (SYSTEMATIC NAME: methyl 3,4,5-trihydroxy-benzoate), C(8)H(8)O(5), is composed of essentially planar mol-ecules [maximum departures from the mean carbon and oxygen skeleton plane of 0.0348 (10) Å]. The H atoms of the three hydroxyl groups, which function as hydrogen-bond donors and acceptors simultaneously, are oriented in the same direction around the aromatic ring. In addition to two intra-molecular hydrogen bonds, each mol-ecule is hydrogen bonded to six others, creating a three-dimensional hydrogen-bonded network. PMID:21581923

  16. Methyl gallate

    OpenAIRE

    Silvina Pagola; Deborah Bebout

    2009-01-01

    The crystal structure of the title compound (systematic name: methyl 3,4,5-trihydroxybenzoate), C8H8O5, is composed of essentially planar molecules [maximum departures from the mean carbon and oxygen skeleton plane of 0.0348 (10) Å]. The H atoms of the three hydroxyl groups, which function as hydrogen-bond donors and acceptors simultaneously, are oriented in the same direction around the aromatic ring. In addition to two intramolecular hydrogen bonds, each molecule is hydroge...

  17. Synthesis of Bioactive Natural Polymethoxyflavones and Their Vinyl Ether Derivatives

    Institute of Scientific and Technical Information of China (English)

    CAI Shuang-lian; LIU Shuang; LIU Li; WANG Qiu-an

    2012-01-01

    Bioactive natural polymethoxyflavones 1-6 and their vinyl ether derivatives 7-15 were synthesized by bromination,aromatic nucleophilic substitution,methylation,benzyl protection,Friedel-Crafts acetylation,aldol condensation,cyclization,DDQ dehydrogenation,regioselective demethylation,debenzylation and O-prenylation or O-farnesylation with resorcinol and appropriate substituted benzaldehydes as starting materials.Among them,compounds 7-15 are new compounds.Natural products 2-4 were firstly total synthesized.The syntheses of compounds 1,5 and 6 were efficiently improved by the new synthetic routes.The structures of all synthetic compounds were confirmed by NMR,IR spectra and MS.

  18. Role of acid catalysis in dimethyl ether conversion processes

    Energy Technology Data Exchange (ETDEWEB)

    Tartamella, T.L.; Lee, S. [Univ. of Akron, OH (United States). Dept. of Chemical Engineering

    1996-12-31

    Acidity plays an important role in the conversion of methanol and dimethyl ether (DME) to hydrocarbons and oxygenates. In the conversion to hydrocarbons over zeolite catalyst, Broensted acidity is the main contributor to the first hydrocarbon formed. Here, acidity is also an important factor in determining olefin, paraffin, and aromatic content in the final product distribution. Catalyst life has also been found to be related to acidity content in zeolites. DME conversion to oxygenates is especially dependent on high acidity catalysts. Superacids like BF{sub 3}, HF-BF{sub 3}, and CF{sub 3}COOH have been used in the past for conversion of DME in carbonylation reactions to form methyl acetate and acetic acid at high pressures. Recently, heteropoly acids and their corresponding metal substituted salts have been used to convert DME to industrially important petrochemicals resulting in shorter reaction times and without the use of harsh operating conditions.

  19. Phytochemical Analysis of Hot Petroleum ether Extracts of Piper nigrum

    Directory of Open Access Journals (Sweden)

    Aditi Gupta

    2013-04-01

    Full Text Available The genus Piper belongs to family piperaceae which has over 700 species distributed in both hemispheres. The piperaceae family is a source of many biologically active photochemical with tremendous potential for medicinal uses. A wide range of secondary metabolites mainly alkaloids, amides and terpenes are reported from the various species of piper which are of great economical and medicinal importance. This paper reports the isolation of various sesqueterpenes such as δ–elemene, δ–cadinene, α–copane, caryophyllene, α–caryophyllene, β–bisabolene, and methyl benzene from the oil of the hot petroleum ether extract of Piper nigrum seeds. These phytochemicals are analysed by GC-MS spectral analysis.

  20. 1-O-Octadecyl-2-O-methyl-rac-glycero-3-phospho[3H-methyl]choline: clinical preparation and metabolism in leukemic Raji cells

    International Nuclear Information System (INIS)

    The ether lipid 1-O-octadecyl-2-O-methyl-rac-glycero-3-phospho[3H-methyl]choline (OM-G3PC) was prepared from the corresponding phosphatidylethanolamine, using [3H]methyliodide as methylation agent. The overall yield was 30%, based on [3H]methyliodide, with an about 2.5 times increase in specific radioactivity. The radiolabeled OM-G3PC was then used in metabolic studies of ether lipids in Raji cells. The main result of this investigation was the observation that the labeled phosphocholine group was transfered from OM-G3PC to diacylglycerol which results in the formation of phosphatidylcholine and 1-O-octadecyl-2-O-methyl-rac-glycerol. This is a new observation, which shows that a phospholipase C-like enzyme can catalyze the transfer of the intact phosphocholine group from OM-G3PC to diacylglycerol. 17 refs.; 1 figure

  1. 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

  2. PENYALUTAN KACANG RENDAH LEMAK MENGGUNAKAN SELULOSA ETER DENGAN PENCELUPAN UNTUK MENGURANGI PENYERAPAN MINYAK SELAMA PENGGORENGAN DAN MENINGKATKAN STABILITAS OKSIDATIF SELAMA PENYIMPANAN [Ether Cellulose Coatings by Dipping on Partially Defatted Peanuts to Reduce Oil Uptake During Frying and to Increase Oxidative Stability During Storage

    OpenAIRE

    Made Darawati1); Yudi Pranoto2)

    2010-01-01

    This research aimed to reduce oil uptake during frying and to improve the oxidative stability of a partially defatted peanuts (PDP) product by coating with ether cellulose-based substances, namely carboxymethyl cellulose (CMC), hydroxyprophyl methyl cellulose (HPMC), methyl cellulose (MC) and hydroxyprophyl cellulose by dipping method. The research was conducted through following steps: preparation of ether cellulose-based edible film and evaluation of the properties, coating application on P...

  3. Solvent-induced crystallization of poly(ether ether ketone)

    Science.gov (United States)

    McPeak, Jennifer Lynne

    The purpose of this study was learn how the diffusion, swelling, and crystallization processes are coupled during solvent-induced crystallization of poly(ether ether ketone) (PEEK). Unoriented amorphous PEEK films were immersed in aprotic organic liquids at ambient temperature and bulk properties or characteristics were monitored as a function of immersion time. The sorption behavior, T g and Tm° suppression, crystallinity, and dynamic mechanical response were correlated as a function of solvent chemistry and immersion time. The saturation time of methylene chloride, 1,3-dichloropropane, tetrahydrofuran, cyclopentanone, chlorobenzene, toluene, diethyl ketone, and ethylbenzene in amorphous PEEK films were found to range from hours to days depending on the level of polymer-solvent interactions. In-situ isochronal DMA spectra show that the Tg of PEEK was suppressed from 150°C to below ambient temperature such that crystallization was kinetically feasible during ambient immersion. In addition, an increase in viscoelastic dispersion was attributed to the presence of crystallinity. From dynamic mass uptake and wide-angle x-ray diffraction (WAXD) results, it was found that the bulk sorption rate was equal to the bulk crystallization rate for all solvent systems that promoted SINC and PEEK exhibited diffusion-limited crystallization, irrespective of the nature of the transport mechanism. In addition, the solvent-induced crystals exhibit preferred orientation as supported by photographic WAXD. A distinct sorption front, observed with scanning electron microscopy, further supports the scenario of diffusion-controlled crystallization and one-dimensional diffusion. Isothermal DMA spectra for THF, cyclopentanone, and chlorobenzene, indicate that, as the solvent diffuses into the films, the stiffness of the polymer decreases at short times, begins to increase, and then reaches a relatively time-independent value. It was determined that the initial decrease in the storage

  4. Synthesis and characterization of mangenese(III) porphyrin supported on imidazole modified chloromethylated MIL-101(Cr): A heterogeneous and reusable catalyst for oxidation of hydrocarbons with sodium periodate

    Energy Technology Data Exchange (ETDEWEB)

    Zadehahmadi, Farnaz; Tangestaninejad, Shahram, E-mail: stanges@sci.ui.ac.ir; Moghadam, Majid, E-mail: moghadamm@sci.ui.ac.ir; Mirkhani, Valiollah, E-mail: mirkhani@sci.ui.ac.ir; Mohammadpoor-Baltork, Iraj; Khosropour, Ahmad R.; Kardanpour, Reihaneh

    2014-10-15

    In the present work, chloromethylated MIL-101(Cr) modified with imidazole, Im-MIL-101, was applied as a support for immobilizing of tetraphenylporphyrinatomangenese(III) chloride. The imidazole-bound MIL-101, Im-MIL-101, not only used as support for immobilization of manganese porphyrin but also applied as a heterogeneous axial base. The Mn(TPP)Cl@Im-MIL-101 catalyst was characterized by UV–vis, FT-IR, X-ray diffraction (XRD), N{sub 2} adsorption, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), elemental analysis and inductively coupled plasma (ICP) methods. The catalytic activity of this new catalytic system was investigated in the alkene epoxidation and alkane hydroxylation using NaIO{sub 4} as an oxidant in CH{sub 3}CN/H{sub 2}O at room temperature. This heterogeneous catalyst is highly efficient, stable and reusable in the oxidation of hydrocarbons. - Highlights: • MIL-101 was modified by covalent post synthetic modification. • Mn(TPP)Cl was anchored to imidazole modified MIL-101 by covalent attachment. • A heterogeneous catalyst was prepared. • The catalyst was used for epoxidation of alkenes and hydroxylation of alkanes. • The catalyst was reusable.

  5. Synthesis and Crystal Structure of 2-Chloromethyl-1H-benzimidazole Nitrate, [ClCH2(C7H6N2)]NO3

    Institute of Scientific and Technical Information of China (English)

    建方方; 卑凤利; 汪信; 陆路德

    2003-01-01

    The title compound [ClCH2(C7H6N2)]NO3 has been prepared and characterized by elemental analysis and X-ray studies. It crystallizes in the monoclinic system, space group P21/n with a = 7.4189(3), b =15.3064(6), c = 9.2657(3) (A。),β = 102.449(2)o, C8H8ClN3O3, Mr = 229.62, V = 1027.44(7) (A。)3, Z = 4, Dc = 1.484 g/cm3, F(000) = 472, μ = 0.363 mm-1, R = 0.0671 and wR = 0.1546. The crystal structure consists of discrete 2-chloromethyl-1H-benzimidazole cations and NO3- anions. The benzimidazole ring with the conjunction carbon atom C(1) is fairly planar, with the deviation from the least plane through the ring atoms is smaller than 0.010(3) (A。). The analytical results of crystal structure show that three different non-covalent interactions in the compound, N-H…O intermolecular hydrogen bonds, C-H…O interaction and π-π stacking interaction, play an important role in the crystal packing.

  6. Synthesis and characterization of mangenese(III) porphyrin supported on imidazole modified chloromethylated MIL-101(Cr): A heterogeneous and reusable catalyst for oxidation of hydrocarbons with sodium periodate

    International Nuclear Information System (INIS)

    In the present work, chloromethylated MIL-101(Cr) modified with imidazole, Im-MIL-101, was applied as a support for immobilizing of tetraphenylporphyrinatomangenese(III) chloride. The imidazole-bound MIL-101, Im-MIL-101, not only used as support for immobilization of manganese porphyrin but also applied as a heterogeneous axial base. The Mn(TPP)Cl@Im-MIL-101 catalyst was characterized by UV–vis, FT-IR, X-ray diffraction (XRD), N2 adsorption, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), elemental analysis and inductively coupled plasma (ICP) methods. The catalytic activity of this new catalytic system was investigated in the alkene epoxidation and alkane hydroxylation using NaIO4 as an oxidant in CH3CN/H2O at room temperature. This heterogeneous catalyst is highly efficient, stable and reusable in the oxidation of hydrocarbons. - Highlights: • MIL-101 was modified by covalent post synthetic modification. • Mn(TPP)Cl was anchored to imidazole modified MIL-101 by covalent attachment. • A heterogeneous catalyst was prepared. • The catalyst was used for epoxidation of alkenes and hydroxylation of alkanes. • The catalyst was reusable

  7. Activity relationships for aromatic crown ethers

    CERN Document Server

    Wilson, M J

    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...

  8. 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 in...

  9. Bulk and interfacial properties of cellulose ethers

    OpenAIRE

    Bodvik, Rasmus

    2012-01-01

    This work summarizes several studies that all concern cellulose ethers of the types methylcellulose (MC) hydroxypropylmethylcellulose (HPMC) and ethyl(hydroxyethyl)cellulose (EHEC). They share the feature of negative temperature response, as they are soluble in water at room temperature but phase separate and sometimes form gels at high temperatures. The different types of viscosity transitions occurring in these three cellulose ethers are well-known. However, earlier studies have not solved ...

  10. 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.

  11. Aminophenols as Efficient Ligand for Copper-Catalyzed Ullmann-type Synthesis of Diaryl Ethers

    International Nuclear Information System (INIS)

    An efficient Cu-catalyzed synthesis of diaryl ethers from various aromatic iodides (bromides) and phenols was developed by using L2(2-((o-toluidino)methyl)phenol) as the ligand. The present protocol is applicable to a variety of phenols and aryl iodides (bromides) containing electron-withdrawing, electron-donating, and sterically demanding substrate combinations under mild conditions. The further study on design and application of new ligands in copper based Ullmann-type coupling reaction is currently ongoing. Carbon-oxygen bonds extensively exist in all kinds of biologically active natural products, important pharmaceutical compounds and polymers. The palladium-catalyzed formation of carbon-oxygen bonds is one of the two major methods available for aryl ether synthesis. However, palladium-based protocols, although successful, have some inherent limitations such as moisture sensitivity, costly metal catalysts, and environmental toxicity

  12. Thin sulfonated poly(ether ether ketone) films for the dehydration of compressed carbon dioxide

    NARCIS (Netherlands)

    Koziara, B.T.

    2015-01-01

    In this thesis, the properties of thin films from highly sulfonated poly(ether ether ketone) (SPEEK) have been investigated within the context of their application as membranes for the dehydration of compressed carbon dioxide. Spectroscopic ellipsometry has been used as the predominant measurement t

  13. Methyl anthranilate as a repellent for western corn rootworm larvae (Coleoptera: Chrysomelidae)

    Science.gov (United States)

    Methyl anthranilate was identified as the active compound in extracts of maize roots that were shown to be repellent to neonate western corn rootworm (Diabrotica virgifera virgifera LeConte) larvae. A bioassay-driven approach was used to isolate the active material from diethyl ether extracts of r...

  14. Effects of Methylated, Organic, and Inorganic Substrates on Microbial Consumption of Dimethyl Sulfide in Estuarine Waters

    OpenAIRE

    Wolfe, Gordon V.; Kiene, Ronald P.

    1993-01-01

    We examined the effects of a variety of amendments on the consumption of [U-14C]dimethyl sulfide in a Georgia salt marsh. Methylated compounds, particularly those with dimethyl groups, significantly inhibited dimethyl sulfide consumption, while nonmethylated substrates had little effect. Dimethyl disulfide and dimethyl ether were the most effective inhibitors tested.

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

    International Nuclear Information System (INIS)

    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

  16. Glycosylated antitumor ether lipids: activity and mechanism of action.

    Science.gov (United States)

    Arthur, Gilbert; Bittman, Robert

    2014-05-01

    Glycosylated antitumor ether lipids (GAELs) are distinguished from the alkyllysophospholipids or alkylphosphocholines classes of antitumor ether lipids (AEL) by the presence of a sugar moiety. Non-phosphorus GAELs, the subject of this review, have a sugar moiety in place of the phosphobase found in alkyllysophospholipids. Analogues of non-phosphorus GAELs with glucose, maltose, arabinose, or disaccharide moieties have been synthesized. Non-phosphorus GAELs with monosaccharides have cytotoxic and antiproliferative effects against cancer cells derived from a wide range of tissues, including drug resistant cell lines. The most active compound of this group to date is 1-O-hexadecyl-2-O-methyl-3-O-(2'-amino-2'-deoxy-β-D-glucopyranosyl)-sn-glycerol (11), which displays in vitro activity similar to or greater than that of ET-18-OCH3, the AEL "gold" standard. While the detailed molecular mechanism of action of non-phosphorus GAELs is not known, the data indicate that non-phosphorus GAELs are taken up by endocytosis and incorporated into early endosomes. The presence of non-phosphorus GAELs perturbs the maturation of the endocytic vesicles, resulting in the formation of large acidic vacuoles. Cell death appears to be the result of the release of cathepsins from the vacuoles into the cytosol and subsequent activation of a death pathway that is independent of the mitochondria and independent of apoptosis. The ability of these GAELs to kill cells via an apoptosis-independent mechanism makes them prime candidates for development of effective compounds against chemo-resistant tumors and cancer stem cells. The disaccharide-linked GAELs do not have cytotoxic activity but rather inhibit cancer cell motility due to the ability of the compounds to block specific calcium-activated potassium channels in cells. The antitumor activities displayed by these experimental compounds augurs well for their eventual development into clinically useful agents for cancer treatment. PMID:24628233

  17. Kapok oil methyl esters

    International Nuclear Information System (INIS)

    The increased need for biodiesel feedstocks has caused various vegetable oils to be examined for this purpose. In the present work, the methyl esters of kapok (Ceiba pentandra) oil were prepared. The essential fuel properties were comprehensively determined and evaluated in comparison to specifications in biodiesel standards and some prior results. The kinematic viscosity of kapok oil methyl esters was greater than expected, an observation traced to the elevated amounts of methyl esters with cyclic moieties. Overall, kapok oil is a potential biodiesel feedstock. The 1H and 13C NMR spectra of kapok methyl esters are reported. - Highlights: • Methyl esters of kapok oil generally acceptable as a biodiesel fuel. • Kapok oil methyl esters a fuel with elevated content of fatty acid methyl esters containing cyclic moieties. • Kinematic viscosity of kapok oil methyl esters elevated likely due to fatty ester methyl esters with cyclic moieties. • Discusses and compares present results with prior literature

  18. 4-[(4′-Chloromethyl-[1,1′-biphenyl]-4-ylmethyl]bis(dimethylglyoximato-κ2N,N′(pyridine-κNcobalt(IIIThis article is dedicated to late Professor B. D. Gupta.

    Directory of Open Access Journals (Sweden)

    Sarvendra Kumar

    2012-02-01

    Full Text Available The title compound, [Co(C14H14Cl(C4H6N2O22(C5H5N], is a model compound for the more complex cobalamines like vitamins B12. The CoIII atom is coordinated by a (4′-chloromethyl-[1,1′-biphenyl]-4-ylmethyl group, an N-bonded pyridine and two N,N′-bidentate dimethylglyoximate ligands in a distorted octahedral geometry. The glyoximate ligands exhibit intramolecular O—H...O hydrogen bonds, which is very common in cobaloxime derivatives.

  19. Injection characteristics of dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Glensvig, M.

    1996-09-01

    Dimethyl ether (DME) has proved to be a new ultra-clean alternative fuel for diesel engines. Engine tests have shown considerably lower NO{sub x} emissions, no particle emissions and lower noise compared to that obtained from normal diesel engine operation. DME also has demonstrated favorable response to Exhaust Gas Recirculation (EGR). The purpose of this investigation was to achieve a better understanding of the fundamental spray behavior of DME. Fundamental spray behaviour was characterized by fuel spray penetration and angle, atomization and droplet size and evaporation. The influence of fuel characteristics, nozzle geometry and ambient pressure on the DME and diesel spray behavior was investigated. Fuel was injected into an unheated injection chamber with a ambient pressure of 15 bar and 25 bar, respectively, giving a simplified simulation of the environment in an operating engine. Two nozzles were studied: a single hole nozzle and a pintle nozzle. A conventional fuel injection system was used for both nozzles. Injection parameters of RPM, throttle position, fuel line length and chamber environment were held constant for both nozzles. The sprays were visualized using schlieren and high speed photography. Results show that the general appearance of the DME spray is similar to that of diesel spray. The core of the DME spray seems less dense and the spray tip less sharp compared to diesel spray, indicating smaller droplets with a lower momentum in the core of the DME spray. Schlieren film shows that with both DME and diesel fuel, the spray tip only consists of liquid and that evaporation occurs after a brief time interval. Penetration of DME is about one third that of diesel using the pintle nozzle. Also, the spray angle is considerably larger for the DME spray compared to the diesel spray. A comparatively smaller difference in penetration is observed using the hole nozzle. Differences in penetration for the hole nozzle are within the limit of the penetration

  20. Dissociation dynamics of methylal

    Energy Technology Data Exchange (ETDEWEB)

    Beaud, P.; Frey, H.-M.; Gerber, T.; Mischler, B.; Radi, P.P.; Tzannis, A.-P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The dissociation of methylal is investigated using mass spectrometry, combined with a pyrolytic radical source and femtosecond pump probe experiments. Based on preliminary results two reaction paths of methylal dissociation are proposed and discussed. (author) 4 fig., 3 refs.

  1. 40 CFR 721.3435 - Butoxy-substituted ether alkane.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butoxy-substituted ether alkane. 721... Substances § 721.3435 Butoxy-substituted ether alkane. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as butoxy-substituted ether...

  2. On new physical reality (on ψ-ether)

    International Nuclear Information System (INIS)

    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

  3. Finkelstein Reaction in Functionalized Crown-ether Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    Xiao Hua WANG; Han Zhi WANG; Hui LIU; Yuan KOU

    2006-01-01

    Functional crown-ether ionic liquids were used as catalytic green solvents of Finkelstein reaction of 1-bromooctane and iodide. The rate and yield of the reaction were obvious improved compared with that using crown ether in water. No free crown ether loss was observed after reaction.

  4. Alkyl Aryl Ether Bond Formation with PhenoFluor**

    OpenAIRE

    Shen, Xiao; Neumann, Constanze N.; Kleinlein, Claudia; Claudia, Nathaniel W.; Ritter, Tobias

    2015-01-01

    An alkyl aryl ether bond formation reaction between phenols and primary and secondary alcohols with PhenoFluor has been developed. The reaction features a broad substrate scope and tolerates many functional groups, and substrates that are challenging for more conventional ether bond forming processes may be coupled. A preliminary mechanistic study indicates reactivity distinct from conventional ether bond formation.

  5. 40 CFR 721.3550 - Dipropylene glycol dimethyl ether.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dipropylene glycol dimethyl ether. 721... Substances § 721.3550 Dipropylene glycol dimethyl ether. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as dipropylene glycol dimethyl ether (PMN...

  6. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Triethylene glycol monomethyl ether... REQUIREMENTS Specific Chemical Test Rules § 799.4440 Triethylene glycol monomethyl ether. (a) Identification of test substance. (1) Triethylene glycol monomethyl ether (TGME, CAS No. 112-35-6) shall be tested...

  7. Synthesis and characterizations of electrospun sulfonated poly (ether ether ketone) SPEEK nanofiber membrane

    Science.gov (United States)

    Hasbullah, N.; Sekak, K. A.; Ibrahim, I.

    2016-07-01

    A novel electrospun polymer electrolyte membrane (PEM) based on Sulfonated Poly (ether ether ketone) were prepared and characterized. The poly (ether ether ketone) PEEK was sulfonated using concentrated sulfuric acid at room temperature for 60 hours reaction time. The degree sulfonation (DS) of the SPEEK are 58% was determined by H1 NMR using area under the peak of the hydrogen shielding at aromatic ring of the SPEEK. Then, the functional group of the SPEEK was determined using Fourier transfer infrared (FTIR) showed O-H vibration at 3433 cm-1 of the sulfonated group (SO2-OH). The effect of the solvent and polymer concentration toward the electrospinning process was investigated which, the DMAc has electrospun ability compared to the DMSO. While, at 20 wt.% of the polymer concentration able to form a fine and uniform nanofiber, this was confirmed by FESEM that shown electrospun fiber mat SPEEK surface at nano scale diameter.

  8. Polyimides Containing Carbonyl and Ether Connecting Groups

    Science.gov (United States)

    Hergenrother, Paul M.; Havens, Stephen J.

    1987-01-01

    Semicrystallinity gives rise to tough, solvent-resistant polymers. New polyimides prepared from reaction of aromatic dianhydrides with new diamines containing carbonyl and ether connecting groups between aromatic rings. Damines prepared from reaction of 4-aminophenol with activated aromatic difluoro compounds in presence of potassium carbonate. These types of polymers have potential applications in molded products, films, adhesives, and composites.

  9. POLYBROMINATED DIPHENYL ETHERS IN SOUTHERN MISSISSIPPI CATFISH

    Science.gov (United States)

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in a wide variety of consumer products. Concerns surrounding these compounds are primarily due do their ubiquitous presence in the environment as well as in human tissue, such as milk, coupled with evidence indi...

  10. Endocrine-mediated effects of two benzene related compounds, 1-chloro-4-(chloromethyl)benzene and 1,3-diethyl benzene, based on subacute oral toxicity studies using rats.

    Science.gov (United States)

    Yamasaki, Kanji; Ishii, Satoko; Kikuno, Tsukasa; Minobe, Yasushi

    2012-08-01

    The purpose of this study was to investigate the endocrine-mediated effects of the benzene-related compounds with reference to Organization for Economic Co-operation and Development (OECD) Test Guideline No. 407. Rats were orally gavaged with 0, 10, 50, and 250 mg/kg/day of 1-chloro-4-(chloromethyl)benzene, and 0, 25, 150, and 1000 mg/kg/day of 1,3-diethyl benzene for at least 28 days, beginning at 8 weeks of age. Thyroid dysfunction was observed in rats given the 1,3-diethyl benzene. Serum T4 values increased in all groups of male rats and in the 1000 mg/kg group of female rats, and TSH values also increased in the 1000 mg/kg groups of both sexes after 28 days' administration. Decreased T3 values were observed in the 1000 mg/kg group of female rats after 28 days' administration, and hormone values increased in the 1000 mg/kg groups of both sexes after the 14-day recovery period. In addition, thyroid weight increased in the 1000 mg/kg groups and thyroid follicular cell hyperplasia was detected in one male rat from the 1000 mg/kg group after 28 days' administration. Endocrine-mediated effects, including thyroid dysfunction were not observed in any groups of rats treated with 1-chloro-4-(chloromethyl)benzene. Our results indicated that endocrine-mediated effects such as thyroid dysfunction were associated with some benzene-related compounds. PMID:22643015

  11. Alkyl aryl ethers in lignite solubilization. 2. Analysis of oil fractions

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1985-03-01

    The FT-I.R. and /sup 1/H N.M.R. spectroscopic analyses of oils or maltenes from a Spanish lignite (Utrillas, Teruel), are reported. These oils were obtained by depolymerization with alkyl aromatic ethers (anisole, 3-methyl anisole and 1,3-dimethoxybenzene) catalyzed by Lewis acids ZnCl/sub 2/, AlCl/sub 3/, SbCl/sub 3/ and BF/sub 3/ (as boron trifluoride etherate), at atmospheric pressure and temperatures <220 C. Bands due to aromatic ethers in the I.R. and N.M.R. spectra of the oils obtained by depolymerization indicate solvent incorporation. Oils obtained by direct lignite extraction showed 25% aromatic H and some H (approximately 3%) without OH groups. These appeared in some oils obtained by depolymerization with AlCl/sub 3/ and were due to secondary reactions with the aromatic extract. Oils derived from processes with good yields showed increases in aromaticity. The extent of substitution of aromatic rings in oils obtained by depolymerization was less than for oils directly extracted. All the oils studied show a low degree of condensation. 15 references.

  12. Ethermix process. Synthesis of ethers from CO/H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Micheli, E.; Antonelli, G.B.; Sanfilippo, D. [Research Division, Snamprogetti S.p.A., S. Donato Milanese (Italy); Cometa, B.; Pecci, G.C. [Euron S.p.A., S. Donato Milanese (Italy)

    1997-12-31

    In the last two decades increasing interest has been devoted world-wide to the conversion of natural gas (NG) to valuable chemical products and fuels, due to its huge reserves and geographic distribution. In this paper with a multi-step process, under development, for the transformation of natural gas, particularly of methane, into ethers, mainly methyl t-butyl ether (MTBE). The process is performed in a series of steps that includes the preparation of a mixture of hydrogen and carbon monoxide in the desired ratio, their reaction addressed to the synthesis of a mixture of methanol and higher alcohols, mainly isobutanol, the dehydration of the higher alcohols fraction to olefins eventually followed by their reaction with methanol to produce the mixture of ethers. Economic evaluations of the process indicate high values of IRR and other indexes that allow the Ethermix technology to be the most convenient route for the transformation of NG into liquid products for motor fuel components. 5 refs.

  13. Calcium carbonate growth in the presence of water soluble cellulose ethers

    International Nuclear Information System (INIS)

    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 CaCO3 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 Mg2+ 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.

  14. 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. PMID:26498966

  15. Radiation-induced cationic curing of vinyl ethers

    International Nuclear Information System (INIS)

    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

  16. Methyltert-butyl Ether (MTBE Degradation by a Microbial Consortium

    Directory of Open Access Journals (Sweden)

    S. B. Mortazavi

    2005-01-01

    Full Text Available Methyl tert-butyl ether (MTBE is added to reformulated gasoline to meet the 1990 Clean Air Act directives. Widespread use of MTBE in gasoline has resulted in groundwater contamination. Because of its undesirable effects on drinking water and ecologically harmful effects, MTBE removal has become a public health and environmental concern. In this study, we have isolated a mixed bacterial culture which is capable of degrading the MTBE as a sole carbon and energy source. This consortium was developed from mixed urban and petrochemical activated sludge after 4 month's enrichment. Enrichment was conducted in batch reactor, fitted with a screw cap and butyl rubber septum. MTBE concentration was measured in head space by gas chromatography. Degradation was determined by MTBE removal. MTBE biodegradation was depended to Dissolved Oxygen (DO concentration and not affected by the changes in concentration of trace element solution or other stimulator Substances. Degradation rates were nearly 1.478 mg MTBE h-1 g-1 (wet biomass and didn't change with MTBE concentration (up 500 mg L-1.

  17. Novel octabrominated phenolic diphenyl ether identified in blue mussels from the Swedish West Coast.

    Science.gov (United States)

    Winnberg, Ulrika; Rydén, Andreas; Löfstrand, Karin; Asplund, Lillemor; Bignert, Anders; Marsh, Göran

    2014-03-18

    Hydroxylated (OH-) and methoxylated (MeO-) polybrominated diphenyl ethers (PBDEs) are compounds present in the marine environment and OH-PBDEs are of toxicological concern and are therefore of interest to monitor in the environment. A phenolic octaBDE was tentatively identified in the phenolic fraction of previously analyzed mussel samples after methylation of the halogenated phenolic compounds (HPCs). The aim of the present study was to confirm the identity of this compound in blue mussels and investigate whether the analyte is diOH- and/or OH-MeO-octaBDE. Two reference standards, 6,6'-dimethoxy-2,2',3,3',4,4',5,5'-octabromodiphenyl ether (6,6'-diMeO-BDE194) and 6-ethoxy-6'-methoxy-2,2',3,3',4,4',5,5'-octabromodiphenyl ether (6-EtO-6'-MeO-BDE194) were prepared via O-arylation of 2,3,4,5-tetrabromo-6-methoxyphenol and 2,3,4,5-tetrabromo-6-ethoxyphenol, respectively, with a novel unsymmetrical diaryliodonium salt, 2,3,4,5-tetrabromo-6-methoxydiphenyliodonium triflate. The GC retention time and GC/MS spectrum of the synthesized 6,6'-diMeO-BDE194 correspond well with the analyte in the methylated phenolic fraction of a mussel extract from a previous study. Structural analysis performed in this study indicate that the synthesized 6,6'-diMeO-BDE194 and 6-EtO-6'-MeO-BDE194 correspond well with 6-hydroxy-6'-methoxy-2,2',3,3',4,4',5,5'-octabromodiphenyl ether (6-OH-6'-MeO-BDE194) after methylation and ethylation, respectively, of the HPCs in the mussel extracts. The compound 6-OH-6'-MeO-BDE194 was identified and quantified in new mussels, sampled in 2012 from two locations on the Swedish west coast, with geometric mean concentrations of 3700 and 410 ng/g fat, respectively. PMID:24559155

  18. Nucleophilic Participation in the Solvolyses of (Arylthio)methyl Chlorides and Derivatives: Application of Simple and Extended Forms of the Grunwald-Winstein Equations.

    Science.gov (United States)

    Kevill, Dennis N; Park, Young Hoon; Park, Byoung-Chun; D'Souza, Malcolm J

    2012-06-01

    The specific rates of solvolysis of chloromethyl phenyl sulfide [(phenylthio)methyl chloride] and its p-chloro-derivative have been determined at 0.0 °C in a wide range of hydroxylic solvents, including several containing a fluroalcohol. Treatment in terms of a two-term Grunwald-Winstein equation, incorporating terms based on solvent ionizing power (Y(Cl)) and solvent nucleophilicity (N(T)) suggest a mechanism similar to that for the solvolyses of tert-butyl chloride, involving in the rate-determining step a nucleophilic solvation of the incipient carbocation in an ionization process. A previous suggestion, that a third-term governed by the aromatic ring parameter (I) is required, is shown both for the new and for the previously studied related substrates to be an artifact, resulting from an appreciable degree of multicollinearity between I values and a linear combination of N(T) and Y(Cl) values. PMID:22711999

  19. Fabrication and properties of poly(polyethylene glycol octadecyl ether methacrylate)

    International Nuclear Information System (INIS)

    Highlights: • Poly(polyethylene glycol octadecyl ether methacrylate) was fabricated. • The crystal form of poly(C18E2MMA) is hexagonal crystal system. • Poly(C18E2MMA) is a polymeric phase change material with a high enthalpy. • Poly(C18E2MMA) is thermal stable below 295 °C. - Abstract: Polyethylene glycol octadecyl ether methacrylate (C18E2MMA) was synthesized using polyethylene glycol octadecyl ether (C18E2) and methyl methacrylate (MMA) as raw materials. Then it was free radical polymerized to form a comb-like polymeric phase change material (PPCM)-poly(polyethylene glycol octadecyl ether methacrylate) (poly(C18E2MMA)). The structure, molecular weight, phase transition behavior, thermal stability and crystallizing properties of poly(C18E2MMA) were investigated using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermal gravimetric analysis (TG), and X-ray diffraction analysis (XRD). The results show that, the number average molecular weight and weight average molecular weight of poly(C18E2MMA) are 27,993 and 107,702 g mol−1, respectively. The melting and crystallizing enthalpy of poly(C18E2MMA) are 73 and 81 J/g, respectively, which starts to melt at 41.1 °C, and crystallize at 35.4 °C. Poly(C18E2MMA) is thermal stable below 295 °C, which implies the high temperature processing application s, i.e. melt-spun thermo-regulated fiber and coated fabric, etc

  20. Fabrication and properties of poly(polyethylene glycol octadecyl ether methacrylate)

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Jie-yun; Tang, Xiao-fen; Zhang, Zhi-li; Zhang, Xing-xiang, E-mail: zhangpolyu@aliyun.com; Shi, Hai-feng

    2013-12-20

    Highlights: • Poly(polyethylene glycol octadecyl ether methacrylate) was fabricated. • The crystal form of poly(C18E2MMA) is hexagonal crystal system. • Poly(C18E2MMA) is a polymeric phase change material with a high enthalpy. • Poly(C18E2MMA) is thermal stable below 295 °C. - Abstract: Polyethylene glycol octadecyl ether methacrylate (C{sub 18}E{sub 2}MMA) was synthesized using polyethylene glycol octadecyl ether (C{sub 18}E{sub 2}) and methyl methacrylate (MMA) as raw materials. Then it was free radical polymerized to form a comb-like polymeric phase change material (PPCM)-poly(polyethylene glycol octadecyl ether methacrylate) (poly(C{sub 18}E{sub 2}MMA)). The structure, molecular weight, phase transition behavior, thermal stability and crystallizing properties of poly(C{sub 18}E{sub 2}MMA) were investigated using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermal gravimetric analysis (TG), and X-ray diffraction analysis (XRD). The results show that, the number average molecular weight and weight average molecular weight of poly(C{sub 18}E{sub 2}MMA) are 27,993 and 107,702 g mol{sup −1}, respectively. The melting and crystallizing enthalpy of poly(C{sub 18}E{sub 2}MMA) are 73 and 81 J/g, respectively, which starts to melt at 41.1 °C, and crystallize at 35.4 °C. Poly(C{sub 18}E{sub 2}MMA) is thermal stable below 295 °C, which implies the high temperature processing application s, i.e. melt-spun thermo-regulated fiber and coated fabric, etc.

  1. Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada

    Science.gov (United States)

    Leiker, T.J.; Abney, S.R.; Goodbred, S.L.; Rosen, Michael R.

    2009-01-01

    Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596????g kg- 1 wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (< 51????g kg- 1 ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

  2. Evaluation of crystallization kinetics of poly (ether-ketone-ketone) and poly (ether-ether-ketone) by DSC

    OpenAIRE

    Gibran da Cunha Vasconcelos; Rogerio Lago Mazur; Edson Cocchieri Botelho; Mirabel Cerqueira Rezende; Michelle Leali Costa

    2010-01-01

    The poly (aryl ether ketones) are used as matrices in advanced composites with high performance due to its high thermal stability, excellent environmental performance and superior mechanical properties. Most of the physical, mechanical and thermodynamic properties of semi-crystalline polymers depend on the degree of crystallinity and morphology of the crystalline regions. Thus, a study on the crystallization process promotes a good prediction of how the manufacturing parameters affect the dev...

  3. Zinc(II)-Chloride Induced Thioalkylation of Aluminium Enolates : Enantioselective Synthesis of Estradiol-3-Methyl-17-tert-Butyl Diether

    OpenAIRE

    Groth, Ulrich; Kohler, Thomas; Taapken, Thomas

    1991-01-01

    Zinc(II)-chloride induced thioalkylation of the aluminium enolate 6 generated by conlugate reduction of the enone 5 leads - directly or via its trimethylsilylenol ether 6 - to alkylated hydrindanones 10 which are important intermediates in the synthesis of 19-norsteroids such as the title compound estradiol-3-methyl-17-tert-butyl diether 12

  4. Emergent gravity and ether-drift experiments

    CERN Document Server

    Consoli, M

    2009-01-01

    In principle, ether-drift experiments could distinguish phenomenologically emergent-gravity approaches, where an effective curvature emerges from hydrodynamic distortions of the same physical, flat-space vacuum, from the more conventional scenario where curvature is considered a fundamental property of space-time down to extremely small length scales and the speed of light represents a universal constant. From an experimental point of view, in this particular context, besides time modulations that might be induced by the Earth's rotation (and its orbital revolution), one should also consider the possibility of random fluctuations of the signal. These might reflect the stochastic nature of the underlying 'quantum ether' and be erroneously interpreted as mere instrumental noise. To test the present interpretation, we have extracted the mean amplitude of the signal from various experiments with different systematics, operating both at room temperature and in the cryogenic regime. They all give the same consisten...

  5. Synthesis of New Liquid Crystalline Diglycidyl Ethers

    Directory of Open Access Journals (Sweden)

    Issam Ahmed Mohammed

    2012-01-01

    Full Text Available The phenolic Schiff bases I–VI were synthesized by condensation reactions between various diamines, namely o-dianisidine, o-tolidine and ethylenediamine with vanillin or p-hydroxybenzaldehyde and subsequent reactions between these phenolic Schiff bases and epichlorohydrin to produce new diglycidyl ethers Ia–VIa. The structures of these compounds were confirmed by CHN, FT-IR, 1H-NMR, and 13C-NMR spectroscopy. Their thermotropic liquid crystalline behavior was studied using differential scanning calorimetry (DSC and polarizing optical microscopy (POM. All the diglycidyl ethers prepared exhibit nematic mesophases, except for Va and VIa, which did not show any transition mesophases, but simply flow to liquids.

  6. Synthesis of New Liquid Crystalline Diglycidyl Ethers

    OpenAIRE

    Issam Ahmed Mohammed; Rashidah Mohamed Hamidi

    2012-01-01

    The phenolic Schiff bases I–VI were synthesized by condensation reactions between various diamines, namely o-dianisidine, o-tolidine and ethylenediamine with vanillin or p-hydroxybenzaldehyde and subsequent reactions between these phenolic Schiff bases and epichlorohydrin to produce new diglycidyl ethers Ia–VIa. The structures of these compounds were confirmed by CHN, FT-IR, 1H-NMR, and 13C-NMR spectroscopy. Their thermotropic liquid crystalline behavior was studied using differential scannin...

  7. Ether bridge formation in loline alkaloid biosynthesis

    OpenAIRE

    Pan, Juan; Bhardwaj, Minakshi; Faulkner, Jerome R.; Nagabhyru, Padmaja; Charlton, Nikki D.; Higashi, Richard M.; Miller, Anne-Frances; Young, Carolyn A; Grossman, Robert B.; Schardl, Christopher L

    2013-01-01

    Lolines are potent insecticidal agents produced by endophytic fungi of cool-season grasses. These alkaloids are composed of a pyrrolizidine ring system and an uncommon ether bridge linking carbons 2 and 7. Previous results indicated that 1-aminopyrrolizidine was a pathway intermediate. We used RNA interference to knock down expression of lolO, resulting in the accumulation of a novel alkaloid identified as exo-1-acetamidopyrrolizidine based on high-resolution MS and NMR. Genomes of endophytes...

  8. Fluoroalkylation of aryl ether perfluorocyclobutyl polymers

    OpenAIRE

    Ligon, Clark; Ameduri, Bruno; Boutevin, Bernard; Smith, Dennis

    2008-01-01

    Post functionalization of aryl ether perfluorocyclobutyl (PFCB) polymers with fluoroalkyl side chains was accomplished with Umemoto's FITS reagents. The fluoroalkylated PFCB polymers (20 % functionalized) showed increases in both hydrophobicity and oleophobicity. Static contact angle for hexadecane was increased after fluoroalkylation from 0° to greater than 30° for the two PFCB polymers tested. Increased oil repellency makes these materials potential candidates for various coatings applicati...

  9. Model for Photodegradation of Polybrominated Diphenyl Ethers

    Czech Academy of Sciences Publication Activity Database

    Veselý, M.; Vajglová, Zuzana; Kotas, Petr; Křišťál, Jiří; Ponec, Robert; Jiřičný, Vladimír

    2015-01-01

    Roč. 22, č. 7 (2015), s. 4949-4963. ISSN 0944-1344 R&D Projects: GA ČR GA104/09/0880; GA ČR(CZ) GAP105/12/0664 Institutional support: RVO:67985858 ; RVO:67179843 Keywords : polybrominated diphenyl ethers * photodegradation model * quantum chemical calculation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.828, year: 2014

  10. Catalytic intermolecular hydroamination of vinyl ethers

    OpenAIRE

    Pahadi, Nirmal K.; Tunge, Jon A.

    2009-01-01

    This manuscript details the development of a palladium-catalyzed hydroamination of vinyl ethers. It is proposed that palladium catalyzes the hydroamination via Bronsted base catalysis, where palladium is protonated by the relatively acidic sulfonamide to generate a palladium hydride as well as the active anionic sulfonamide nucleophile. Thus, this process is distinct from known palladium-catalyzed hydroaminations of styrene derivatives that utilize less acidic amines.

  11. Poly(Arylene Ether Imidazole) Surface Films

    Science.gov (United States)

    Connell, John W.; Towell, Timothy W.; Tompkins, Stephen S.

    1993-01-01

    Films adhere well to some substrates, provide smooth surfaces, and facilitate release from molds. Thin films of thermoplastic poly(arylene ether imidazole)s (PAEI's) particularly suitable for use as surface modifiers for graphite/epoxy or graphite/bismaleimide composite panels. Molecule of PAEI includes imidazole groups along its backbone that co-cure with epoxies or bismaleimides during processing. Films thermally stable and resistant to bombardment by energetic electrons.

  12. 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.

  13. Methyl Anthranilate as a Repellent for Western Corn Rootworm Larvae (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Bernklau, E J; Hibbard, B E; Norton, A P; Bjostad, L B

    2016-08-01

    Methyl anthranilate was identified as the active compound in extracts of maize (Zea mays L.) roots that were shown to be repellent to neonate western corn rootworm (Diabrotica virgifera virgifera LeConte) larvae. A bioassay-driven approach was used to isolate the active material from diethyl ether extracts of roots from germinating maize seeds. Separation of the extract on a Florisil column yielded an active fraction of 90:10 hexane:diethyl ether. Analysis with gas chromatography-mass spectrometry identified two compounds in the active fraction: indole (2,3-benzopyrrole) and methyl anthranilate (methyl 2-aminobenzoate). When tested in behavioral bioassays, methyl anthranilate elicited a significant (P repellent response at doses of 1, 10, and 100 µg. In subsequent single-choice bioassays, 1, 10, and 100 µg of methyl anthranilate prevented larvae from approaching 10 mmol/mol concentrations of carbon dioxide, which is normally highly attractive to the larvae. Indole, the other compound identified from the active fraction, did not elicit a behavioral response by the larvae. Methyl anthranilate has potential for development as a management tool for western corn rootworm larvae and may be best suited for use in a push-pull control strategy. PMID:27122493

  14. 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.

  15. Electroless nickel-phosphorus coating on poly (ether ether ketone)/carbon nanotubes composite

    Science.gov (United States)

    Zhai, Tong; Di, Lizhi; Yang, De'an

    2014-05-01

    In order to improve electromagnetic shielding property of poly (ether ether ketone)/carbon nanotubes composite, a nickel-phosphorus coating was covered on the composite by electroless plating. The morphologies of the substrates and the coatings were characterized by SEM. XPS was performed to analyze the surface composition and chemical states before and after chemical etching. The results showed that lots of microscopic holes appeared and evenly distributed on the surface, and the concentration of hydrophilic groups on the surface increased after the composite was etched. Thermal shock test showed that the adhesive strength between the coating and the composite was good.

  16. Azidated Ether-Butadiene-Ether Block Copolymers as Binders for Solid Propellants

    Science.gov (United States)

    Cappello, Miriam; Lamia, Pietro; Mura, Claudio; Polacco, Giovanni; Filippi, Sara

    2016-07-01

    Polymeric binders for solid propellants are usually based on hydroxyl-terminated polybutadiene (HTPB), which does not contribute to the overall energy output. Azidic polyethers represent an interesting alternative but may have poorer mechanical properties. Polybutadiene-polyether copolymers may combine the advantages of both. Four different ether-butadiene-ether triblock copolymers were prepared and azidated starting from halogenated and/or tosylated monomers using HTPB as initiator. The presence of the butadiene block complicates the azidation step and reduces the storage stability of the azidic polymer. Nevertheless, the procedure allows modifying the binder properties by varying the type and lengths of the energetic blocks.

  17. The First Example of Cation Radical Induced Ether Cleavage of Benzyl Phenyl Ether

    International Nuclear Information System (INIS)

    A thermally stable benzyl phenyl ether has been shown to cleavage under mild conditions. The new reaction described herein further expands the chemistry of the ether cleavage by cation radicals. Over the last several years, our lab has discovered cation radical-induced oxidative C-O bond cleavages such as carbonates (eq 1), carbamates (eq 2), peroxides (eq 3), and alcohols (eq 4), where R is either tert-butyl or benzyl. It was recognized from those reactions that carbocationic chemistry with C-O bond cleavages was predominant, with a 2:1 stoichiometry of Th+·:oxidized molecules

  18. Enzymatic aryl-O-methyl-14C labeling of model lignin monomers

    International Nuclear Information System (INIS)

    Aryl-O-methyl ethers are abundant in aerobic and anaerobic environments. In particular, lignin is composed of units of this type. Lignin monomers specifically radiolabeled in methoxy, side chain, and ring carbons have been synthesized by chemical procedures and are important in studies of lignin synthesis and degradation, humus formation, and microbial O-demethylation. In this paper attention is drawn to an enzymatic procedure for preparing O-methyl-14C-labeled aromatic lignin monomers which has not previously been exploited in microbial ecology and physiology studies and which has several advantages compared with chemical synthesis procedures. O-[methyl-14C]vanillic and O-[methyl-14C]ferulic acids were prepared with S-[methyl-14C]adenosyl-L-methionine as the methyl donor, using commercially obtained porcine liver catechol-O-methyltransferase (EC 2.1.1.6). The specific activity of the methylated products was the same as that of the methyl donor, a maximum of about 58 μCi/μmol, and the yields were 42% (vanillate) and 35% (ferulate). Thus lignin monomers are readily prepared as O-methylated products of the catechol-O-methyltransferase reaction and, with this enzyme method of preparation, would be more widely available than labeled compounds which require chemical synthesis

  19. 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.

  20. Absorption of some glycol ethers through human skin in vitro.

    OpenAIRE

    Dugard, P H; M. Walker; Mawdsley, S J; Scott, R.C.

    1984-01-01

    To assist evaluation of the hazards of skin contact with selected undiluted glycol ethers, their absorption across isolated human abdominal epidermis was measured in vitro. Epidermal membranes were set up in glass diffusion cells and, following an initial determination of permeability to tritiated water, excess undiluted glycol ether was applied to the outer surface for 8 hr. The appearance of glycol ether in an aqueous "receptor" phase bathing the underside of the epidermis was quantified by...

  1. SYNTHESIS OF POLY ( ETHER-URETHANE) CONTAINING PENDANT AMINO GROUP

    Institute of Scientific and Technical Information of China (English)

    WU Jinhuang; SUN Yanhui; FENG Xinde

    1989-01-01

    This paper is concerned with the synthesis of poly (ether-urethane) with pendant amino groups. The copolyether produced by ring opening copolymerization of tetrahydrofuran and epibromohydrin was treated with sodium azide in dimethylformamide to form azido substituted copolyether. The poly (ether-urethane) made from it was subjected to reduction reaction to convert azido group to amino group. The stress-strain behavior and dynamic-mechanical properties of poly (ether-urethane) containing pendant amino groups were studied.

  2. A novel pentiptycene bis(crown ether)-based [2](2)rotaxane whose two DB24C8 rings act as flapping wings of a butterfly.

    Science.gov (United States)

    Ma, Ying-Xian; Meng, Zheng; Chen, Chuan-Feng

    2014-04-01

    A novel [2](2)rotaxane based on pentiptycene-derived bis(crown ether) can be efficiently synthesized via a "click chemistry" method and the subsequent N-methylation. Due to the different affinities of DB24C8 with the ammonium and triazolium stations, the wing-flapping movement of the DB24C8 "wings" in the [2](2)rotaxane can be easily achieved by acid/base stimulus. PMID:24635015

  3. 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. PMID:26475513

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

    International Nuclear Information System (INIS)

    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 LiClO4 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 LiClO4, 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

  5. Unprecedented reactions: from epichlorohydrin to epoxyglycidyl substituted divinyl ether and its conversion into epoxyglycidyl propargyl ether

    Science.gov (United States)

    Yao, Yiwu; Li, Zheng; Qiu, Yatao; Bai, Jinhong; Su, Jinyue; Zhang, Dayong; Jiang, Sheng

    2015-09-01

    The reaction of epichlorohydrin with concentrated sodium hydroxide in hexane under phase transfer conditions has surprisingly led to the formation of the symmetrical di(3-epoxyglycidyl-1-propenyl) ether 1 which contains both nucleophilic and electrophilic moieties. When it was reacted with n-butyllithium, intermediate 1 once again surprisingly generated epoxyglycidyl propargyl ether, which was further reacted in situ with a variety of benzaldehydes to furnish the corresponding substituted propargylic alcohols in good yields. While the reaction is operationally simple, it provides a powerful method for the synthesis of the important products from commodity materials such as epichlorohydrin. Moreover, these reactions may have revealed that some fundamental properties of the hydroxide anion in those once thought straightforward reactions are not well understood. A careful analysis of the experimental data suggests that an unprecedented concerted elimination of the epoxyglycidyl ether with sodium hydroxide may be operative and an alpha deprotonation followed by alpha elimination of the di(3-epoxyglycidyl-1-propenyl) ether with alkyllithium may have been involved.

  6. 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.

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

    International Nuclear Information System (INIS)

    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 (t0), 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.

  8. Copper Promoted Synthesis of Diaryl Ethers

    OpenAIRE

    Ghosh, Rajshekhar; Samuelson, Ashoka G

    2004-01-01

    An efficient protocol using copper based reagents for the coupling of aryl halides with phenols to generate diaryl ethers is described. Acopper( I) complex, [ Cu( CH3CN) (4)] ClO4, or the readily available copper( II) source, CuCO3 . Cu( OH) (2) . H2O ( in combination with potassium phosphate), can be used. Aryl halides and phenols with different steric and electronic demands have been used to assess the efficiency of the procedure. The latter source of copper gives better yields under all co...

  9. 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.

  10. 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...

  11. Synthesis and Biophysical Characterization of Chlorambucil Anticancer Ether Lipid Prodrugs

    DEFF Research Database (Denmark)

    Pedersen, Palle Jacob; Christensen, Mikkel Stochkendahl; Ruysschaert, Tristan;

    2009-01-01

    The synthesis and biophysical characterization of four prodrug ether phospholipid conjugates are described. The lipids are prepared from the anticancer drug chlorambucil and have C16 and C18 ether chains with phosphatidylcholine or phosphatidylglycerol headgroups. All four prodrugs have the abili...

  12. 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

    1997-01-01

    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 nanc

  13. Biosynthesis of archaeal membrane ether lipids.

    Science.gov (United States)

    Jain, Samta; Caforio, Antonella; Driessen, Arnold J M

    2014-01-01

    A vital function of the cell membrane in all living organism is to maintain the membrane permeability barrier and fluidity. The composition of the phospholipid bilayer is distinct in archaea when compared to bacteria and eukarya. In archaea, isoprenoid hydrocarbon side chains are linked via an ether bond to the sn-glycerol-1-phosphate backbone. In bacteria and eukarya on the other hand, fatty acid side chains are linked via an ester bond to the sn-glycerol-3-phosphate backbone. The polar head groups are globally shared in the three domains of life. The unique membrane lipids of archaea have been implicated not only in the survival and adaptation of the organisms to extreme environments but also to form the basis of the membrane composition of the last universal common ancestor (LUCA). In nature, a diverse range of archaeal lipids is found, the most common are the diether (or archaeol) and the tetraether (or caldarchaeol) lipids that form a monolayer. Variations in chain length, cyclization and other modifications lead to diversification of these lipids. The biosynthesis of these lipids is not yet well understood however progress in the last decade has led to a comprehensive understanding of the biosynthesis of archaeol. This review describes the current knowledge of the biosynthetic pathway of archaeal ether lipids; insights on the stability and robustness of archaeal lipid membranes; and evolutionary aspects of the lipid divide and the LUCA. It examines recent advances made in the field of pathway reconstruction in bacteria. PMID:25505460

  14. Process for producing cyclic ethers from lactones

    International Nuclear Information System (INIS)

    Cyclic ethers are produced from lactones by a process which comprises directly synthesizing cyclic ethers by the reduction of the carbonyl radicals of lactones with trichlorosilane either by the action of ionizing, visible, or ultraviolet radiations, or alternately in the presence of free radical initiators. For instance, gamma-butyl lactone mixed with trichlorosilane yields 82% of tetrahydrofuran when only irradiated with gamma-rays, whereas it yields 94% of tetrahydrofuran when exposed to ultraviolet radiations in the presence of a little amount of peroxide. Such a high yield reveals that the ring opening reaction and the ring closing reaction are not continuous, but are chain reactions in which carbonyl radicals are selectively reduced to methylene radicals without cutting the backbone structure. In one embodiment, lactone and trichlorosilane were de-aired by the vacuum refrigeration method respectively, and after being mixed in the proportion of 4:1 in a tube they were exposed to gamma-rays from a Co-60 source at room temperature at a dose rate of 3 x 105 rad/hr. In another embodiment, a de-aired mixture of lactone and ditertiary butyl peroxide with de-aired trichlorosilane in a tube were exposed to a high voltage mercury lamp for 2 hours. Ninety four percent of gamma-tetrahydrofuran, 92.2% of valerolactone tetrahydropyran or 95.7% of caprolactone hexamethylene oxide were obtained. (Iwakiri, K.)

  15. Lysine methylation: beyond histones

    Institute of Scientific and Technical Information of China (English)

    Xi Zhang; Hong Wen; Xiaobing Shi

    2012-01-01

    Posttranslational modifications (PTMs) of histone proteins,such as acetylation,methylation,phosphorylation,and ubiquitylation,play essential roles in regulating chromatin dynamics.Combinations of different modifications on the histone proteins,termed 'histone code' in many cases,extend the information potential of the genetic code by regulating DNA at the epigenetic level.Many PTMs occur on non-histone proteins as well as histones,regulating protein-protein interactions,stability,localization,and/or enzymatic activities of proteins involved in diverse cellular processes.Although protein phosphorylation,ubiquitylation,and acetylation have been extensively studied,only a few proteins other than histones have been reported that can be modified by lysine methylation.This review summarizes the current progress on lysine methylation of nonhistone proteins,and we propose that lysine methylation,like phosphorylation and acetylation,is a common PTM that regulates proteins in diverse cellular processes.

  16. Methylated DNA in Borrelia species.

    OpenAIRE

    Hughes, C A; Johnson, R C

    1990-01-01

    The DNA of Borrelia species was examined for the presence of methylated GATC sequences. The relapsing-fever Borrelia sp., B. coriaceae, and only 3 of 22 strains of B. burgdorferi contained adenine methylation systems. B. anserina lacked an adenine methylation system. Fundamental differences in DNA methylation exist among members of the genus Borrelia.

  17. Inheritance of Cytosine Methylation.

    Science.gov (United States)

    Tillo, Desiree; Mukherjee, Sanjit; Vinson, Charles

    2016-11-01

    There are numerous examples of parental transgenerational inheritance that is epigenetic. The informational molecules include RNA, chromatin modifications, and cytosine methylation. With advances in DNA sequencing technologies, the molecular and epigenetic mechanisms mediating these effects are now starting to be uncovered. This mini-review will highlight some of the examples of epigenetic inheritance, the establishment of cytosine methylation in sperm, and recent genomic studies linking sperm cytosine methylation to epigenetic effects on offspring. A recent paper examining changes in diet and sperm cytosine methylation from pools of eight animals each, found differences between a normal diet, a high fat diet, and a low protein diet. However, epivariation between individuals within a group was greater than the differences between groups obscuring any potential methylation changes linked to diet. Learning more about epivariation may help unravel the mechanisms that regulate cytosine methylation. In addition, other experimental and genetic systems may also produce more dramatic changes in the sperm methylome, making it easier to unravel potential transgenerational phenomena. J. Cell. Physiol. 231: 2346-2352, 2016. © 2016 Wiley Periodicals, Inc. PMID:26910768

  18. The effects of water on the morphology and the swelling behavior of sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

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

    2016-01-01

    Thin sulfonated poly(ether ether ketone) films swell excessively in water. The extent of water-induced swelling is shown to be correlated with the optical anisotropy of the films, due to two distinct phenomena. Firstly, the optical anisotropy is directly related to the amount of water taken up from

  19. Steam Reforming of Dimethyl Ether by Gliding Arc Gas Discharge Plasma for Hydrogen Production

    Institute of Scientific and Technical Information of China (English)

    王保伟; 孙启梅; 吕一军; 杨美琳; 闫文娟

    2014-01-01

    Gliding arc gas discharge plasma was used for the generation of hydrogen from steam reforming of di-methyl ether (DME). A systemic procedure was employed to determine the suitable experimental conditions. It was found that DME conversion first increased up to the maximum and then decreased slightly with the increase of added water and air. The increase of total feed gas flow rate resulted in the decrease of DME conversion and hy-drogen yield, but hydrogen energy consumption dropped down to the lowest as total feed gas flow rate increased to 76 ml·min-1. Larger electrode gap and higher discharge voltage were advantageous. Electrode shape had an impor-tant effect on the conversion of DME and production of H2. Among the five electrodes, electrode 2# with valid length of 55 mm and the radian of 34 degrees of the top electrode section was the best option, which enhanced ob-viously the conversion of DME.

  20. 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.

  1. 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.

  2. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  3. 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)

  4. Polymeric 32-channel arrayed waveguide grating multiplexer using fluorinated poly (ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    Fei Wang(王菲); Wei Sun(孙伟); Aize Li(李艾泽); Maobin Yi(衣茂斌); Zhenhua Jiang(姜振华); Daming Zhang(张大明)

    2004-01-01

    In wavelength division multiplexing (WDM) systems, an arrayed waveguide grating (AWG) multiplexer is a key component. A polymeric AWG multiplexer has recently attracted much attention due to its low cost processing and a potential of integration with other devices. Fluorinated poly (ether ether ketone)(FPEEK) is excellent material for fabrication of optical waveguides due to its low absorption loss at 1.55-μm wavelength and high thermal stability. A 32-channel AWG multiplexer has been designed based on the grating diffraction theory and fabricated using newly synthesized FPEEK. During the fabrication process of the Polymer/Si AWG device, spin coating, vaporizing, photolithographic patterning and reactive ion etching (RIE) are used. The AWG multiplexer measurement system is based on a tunable semiconductor laser, infrared camera and a Peltier-type heater. The device exhibits a wavelength channel spacing of 0.8nm and a center wavelength of 1548 nm in the room temperature.

  5. 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.

  6. 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. PMID:26954085

  7. Effects of spinneret structure on poly-ether-ether-ketone fibers by screw extrusion

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xin-ying; YI Xiao-su; XU Zhong-bin; XU Ya-hong

    2005-01-01

    According to the characters of poly-ether-ether-ketone (PEEK) plastic, the spinnerets with three kinds of different structure were designed. The effects of spinneret structure on the melt spinning conditions, melt flow instability of the screw extrusion, and the performance of PEEK fibers were studied. The results show that the appropriate screw extrusion temperature is 370 -385℃. The PEEK fibers extruded using the spinnerets with L/D= 6,8 holes and 0.5 mm in diameter have better performances. The performances of PEEK fibers are related to the diameter of the spinneret hole. Increasing the L/D value of the spinnerets can not always improve the surface quality and the performances of PEEK fibers. The extrusion pressure is about 50% of that of the spinneret with 12 holes and 0.3 mm in diameter.

  8. Hydrophilization of Poly(ether ether ketone) Films by Surface-initiated Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Fristrup, Charlotte Juel; Eskimergen, Rüya; Burkrinsky, J.T.;

    2008-01-01

    Poly(ether ether ketone) (PEEK) replaces aluminum and other metals in aerospace, electronics, medical, and automotive applications. Therefore, the demand for metallization of PEEK is continuously increasing. Metals seldom bond to a polymer without undergoing some chemical interaction - this is the......-modified PEEK using Surface-Initiated Atom Transfer Radical Polymerization (SI ATRP). Surface reduction of PEEK to form hydroxyl groups [1, 2, 3] was .performed prior to the attachment of 2-bromoisobutyrate initiating groups. Each modification step of PEEK as well as the polymer grafting was followed and...... mechanism leading to good adhesion. From the different types of bonding, the covalent bond at the polymer - metal interface is the strongest. In this work the surface ofPEEK is functionalized by covalently bounding of hydrophilic polymer brushes ofpoly(ethyleneglycol) methacrylate (PEGMA) from initiator...

  9. Modification of Poly(ether ether ketone Polymer for Fuel Cell Application

    Directory of Open Access Journals (Sweden)

    Devesh Shukla

    2013-01-01

    Full Text Available Polyelectrolyte membrane (PEM is an important part of PEM fuel cell. Nafion is a commercially known membrane which gives the satisfactory result in PEM fuel cell operating at low temperature. Present research paper includes functionalization of Poly(ether ether ketone (PEEK polymer with phosphonic acid group. The functionalization was done with the help of nickel-based catalyst. Further, the polymer was characterized by the FTIR, EDAX, DSC, TGA, and 1H NMR, and it was found that PEEK polymer was functionalized with phosphonic acid group with good thermal stability in comparison to virgin PEEK. Finally, the thin films of functionalized polymer were prepared by solution casting method, and proton conductivity of film samples was measured by impedance spectra whose value was found satisfactory with good thermal stability in comparison to commercially available Nafion membrane.

  10. High-resolution EVLA image of dimethyl ether (CH$_{3}$)$_{2}$O in Orion--KL

    CERN Document Server

    Favre, C; Remijan, A J; Brouillet, N; Wilson, T L; Deapois, D; Baudry, A

    2011-01-01

    We report the first sub-arc second (0.65$\\arcsec$ $\\times$ 0.51$\\arcsec$) image of the dimethyl ether molecule, (CH$_{3}$)$_{2}$O, toward the Orion Kleinmann-Low nebula (Orion--KL). The observations were carried at 43.4 GHz with the Expanded Very Large Array (EVLA). The distribution of the lower energy transition 6$_{1,5} - 6_{0,6}$, EE (E$\\rm_{u}$ = 21 K) mapped in this study is in excellent agreement with the published dimethyl ether emission maps imaged with a lower resolution. The main emission peaks are observed toward the Compact Ridge and Hot Core southwest components, at the northern parts of the Compact Ridge and in an intermediate position between the Compact Ridge and the Hot Core. A notable result is that the distribution of dimethyl ether is very similar to that of another important larger O-bearing species, the methyl formate (HCOOCH$_{3}$), imaged at lower resolution. Our study shows that higher spectral resolution (WIDAR correlator) and increased spectral coverage provided by the EVLA offer ne...

  11. 2-Methyltetrahydrofuran and cyclopentyl methyl ether for green solid-phase peptide synthesis.

    Science.gov (United States)

    Jad, Yahya E; Acosta, Gerardo A; Khattab, Sherine N; de la Torre, Beatriz G; Govender, Thavendran; Kruger, Hendrik G; El-Faham, Ayman; Albericio, Fernando

    2016-02-01

    2-MeTHF and CPME were evaluated as greener alternatives for the most employed solvents in peptide synthesis. The ability of these solvents to dissolve amino acid derivatives and a range of coupling reagents were evaluated as well as the swelling of polystyrene and polyethylene glycol resins. In addition, racemization and coupling efficiencies were also determined. We concluded that the use of 2-MeTHF with combination of DIC/OxymaPure gave the lowest racemization level during stepwise synthesis of Z-Phg-Pro-NH2 and the highest purity during SPPS of Aib-enkephalin pentapeptide (H-Tyr-Aib-Aib-Phe-Leu-NH2). PMID:26403847

  12. TRANSPORT OF METHYL TERT-BUTYL ETHER THROUGH ALFALFA PLANTS. (R825549C062)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  13. Modeling Of A Reactive Distillation Column: Methyl Tertiary Butyl Ether (Mtbe Simulation Studies

    Directory of Open Access Journals (Sweden)

    Ismail Mohd Saaid Abdul Rahman Mohamed and Subhash Bhatia

    2012-10-01

    Full Text Available A process simulation stage-wise reactive distillation column model formulated from equilibrium stage theory was developed. The algorithm for solving mathematical model represented by sets of differential-algebraic equations was based on relaxation method. Numerical integration scheme based on backward differentiation formula was selected for solving the stiffness of differential-algebraic equations. Simulations were performed on a personal computer (PC Pentium processor through a developed computer program using FORTRAN90 programming language. The proposed model was validated by comparing the simulated results with the published simulation results and with the pilot plant data from the literature. The model was capable of predicting high isobutene conversion for heterogeneous system, as desirable in industrial MTBE production process. The comparisons on temperature profiles, liquid composition profile and operating conditions of reactive distillation column also showed promising results. Therefore the proposed model can be used as a tool for the development and simulation of reactive distillation column.Keywords: Modeling, simulation, reactive distillation, relaxation method, equilibrium stage, heterogeneous, MTBE

  14. Modeling Of A Reactive Distillation Column: Methyl Tertiary Butyl Ether (Mtbe) Simulation Studies

    OpenAIRE

    2012-01-01

    A process simulation stage-wise reactive distillation column model formulated from equilibrium stage theory was developed. The algorithm for solving mathematical model represented by sets of differential-algebraic equations was based on relaxation method. Numerical integration scheme based on backward differentiation formula was selected for solving the stiffness of differential-algebraic equations. Simulations were performed on a personal computer (PC Pentium processor) through a developed c...

  15. 76 FR 69659 - Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether Methacrylate Graft...

    Science.gov (United States)

    2011-11-09

    ...-5805. II. Background and Statutory Findings In the Federal Register of Friday, August 26, 2011 (76 FR... and Review (58 FR 51735, October 4, 1993). Because this final rule has been exempted from review under... Regulations That Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355, May 22, 2001)...

  16. Effect of Methyl tert-Butyl Ether in Standard Tests for Mutagenicity and Environmental Toxicity

    Czech Academy of Sciences Publication Activity Database

    Vosáhlíková, M.; Cajthaml, Tomáš; Demnerová, K.; Pazlarová, Jarmila

    2006-01-01

    Roč. 21, č. 6 (2006), s. 599-605. ISSN 1520-4081 Institutional research plan: CEZ:AV0Z50200510 Keywords : toxicity * mtbe * ames test Subject RIV: EE - Microbiology, Virology Impact factor: 1.582, year: 2006

  17. Novel architecture design of block copolymers of ethylene glycol methyl ether methacrylate and carboxybetaine acrylamide

    Czech Academy of Sciences Publication Activity Database

    Rodriguez-Emmenegger, Cesar; Hasan, E.; Brynda, Eduard; Houska, Milan; Sedláková, Zdeňka; Bologna Alles, A.; Huck, W.

    Praha : Institute of Macromolecular Chemistry, 2009. s. 111. ISBN 978-80-85009-59-0. [Prague Meetings on Macromolecules /73./ New Frontiers in Macromolecular Science: From Macromolecular Concepts of Living Matter to Polymers for Better Quality of Life. 05.07.2009-09.07.2009, Prague] R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z40500505 Keywords : block copolymers Subject RIV: CD - Macromolecular Chemistry

  18. Excess molar enthalpies of the binary systems: (Dibutyl ether + isomers of pentanol) at T = (298.15 and 308.15) K

    International Nuclear Information System (INIS)

    Highlights: • We present excess molar enthalpies for dibutyl ether with isomers of pentanol. • We present the effective-reduced dipole moments for isomers of pentanol. • All values of excess molar enthalpies for the studied mixtures are positive. • The effective-reduced dipole moments of the isomers of pentanol are similar. - Abstract: In this work, we present the experimental measurements of excess molar enthalpies for the binary systems of dibutyl ether with different isomers of pentanol: 1-pentanol, 2-pentanol, 3-pentanol, 3-methyl-2-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-methyl-2-butanol; all of them at T = (298.15 and 308.15) K and atmospheric pressure. Our goal was to determine the influence of the OH-group position on the different isomers of pentanol in the excess molar enthalpies of the binary systems studied. For this purpose we have analysed their experimental effective-reduced dipole moments. All values of excess molar enthalpies for the mixtures studied are positive whereas the results obtained for the effective-reduced dipole moments of the isomers of pentanol are similar

  19. 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)

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

    International Nuclear Information System (INIS)

    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%

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

    International Nuclear Information System (INIS)

    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 × 10−7 cm2/s) compared to a Nafion 212 membrane (5.37 × 10−7 cm2/s)

  2. The Lubrication Qualities of Dimethyl Ether (DME)

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Sorenson, Spencer C; Jakobsen, J.

    2002-01-01

    Dimethyl Ether (DME) has been recognised as a clean alternative for diesel oil for some years now. Fuelling diesel engines with DME solves their two most significant problems: The emission of particulate matter is virtually eliminated and the level of NOx can be reduced considerably by exhaust gas...... the viscosity, which plays a major role in the hydrodynamic lubrication regime. The lubricity of DME has been established by the medium frequency pressurised reciprocating rig (MFPRR) to be very low compared to the one of diesel oil. But the DME film limits the wear extent significantly compared to...... the case of dry sliding. By mixing DME with additives, the lubricity level is easily raised even above the one of diesel oil. The viscosity of DME has been established by the volatile fuel viscometer (VFVM) to be as low as 0.185 cSt @ 25 oC. It is also shown that this viscosity cannot be raised...

  3. Acyclic archaebacterial ether lipids in swamp sediments

    Science.gov (United States)

    Pauly, George G.; Van Vleet, Edward S.

    1986-06-01

    Acyclic phytanyl diether glycerol and biphytanyl ether lipids have been quantified in two modern swamp sediment cores in concentrations ranging up to 360 μg/ml porewater. Methanogenic bacteria are the only known source organisms which can inhabit the swamp sediments. Variations in relative abundance between these lipids may reflect taxonomic changes in methanogen populations or the stage of growth. Maxima in methanogen lipid concentrations coincide with local maxima of 13C of organic matter, possibly the result of a pool effect on CO 2 or acetate. Methane production estimates calculated from lipid concentrations in swamp sediments range from 0.1 to 1.3 mmol cm -2 yr -1, values which are consistent with published methane fluxes.

  4. Experimental analysis of a Diesel Engine fuelled with Biodiesel Blend using Di-ethyl ether as fuel additives

    Directory of Open Access Journals (Sweden)

    AR.Manickam

    2014-10-01

    Full Text Available This study investigates the use of di-ethyl ether (DEE as an oxygenated additive with 20% Karanja methyl ester diesel blend (B20. Experiments were conducted to study the effect of adding 5%, 10% and 15% di-ethyl ether (DEE with Karanja methyl ester (KME on performance, emission and combustion characteristics of a direct injection diesel engine operated at a constant speed of 1500 rpm at different operating conditions. The results showed that the brake thermal efficiency slightly increased and the exhaust emissions are significantly decreased with DEE with biodiesel at full load conditions. The results revealed that an optimum blend of 10% DEE added with biodiesel resulted in a slight decrease in brake specific fuel consumption (BSFC of 8.6% while the brake thermal efficiency increased by 4.8%. DEE added with 20% biodiesel showed lower nitrogen oxide (NO emission and slightly higher carbon dioxide (CO2 emission as compared to diesel. Carbon monoxide (CO, hydrocarbon (HC and smoke emissions decreased by 40%, 26% and 12% respectively compared to B20 biodiesel. The combustion characteristics like higher cylinder pressure, heat release rate and shorter ignition delay period were observed with DEE added biodiesel at full load conditions.

  5. Synthesis and Adsorption Property of Dihydroxyl Azacrown Ether-Grafted Chitosan

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan. The adsorption property of the azacrown ether chitosan for Pb2+, Cr3+, and Ag+, were determined. The experimental results showed that the dihydroxyl azacrown ether grafted chitosan has high adsorption capacity and high selectivity for some metal ions.

  6. 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.

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

    International Nuclear Information System (INIS)

    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-d6) solution of the purified polymer using 1H 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 × 10−3 Scm−1 at 30°C and 3.383 × 10−3 Scm−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

  8. [DNA methylation in obesity].

    Science.gov (United States)

    Pokrywka, Małgorzata; Kieć-Wilk, Beata; Polus, Anna; Wybrańska, Iwona

    2014-01-01

    The number of overweight and obese people is increasing at an alarming rate, especially in the developed and developing countries. Obesity is a major risk factor for diabetes, cardiovascular disease, and cancer, and in consequence for premature death. The development of obesity results from the interplay of both genetic and environmental factors, which include sedentary life style and abnormal eating habits. In the past few years a number of events accompanying obesity, affecting expression of genes which are not directly connected with the DNA base sequence (e.g. epigenetic changes), have been described. Epigenetic processes include DNA methylation, histone modifications such as acetylation, methylation, phosphorylation, ubiquitination, and sumoylation, as well as non-coding micro-RNA (miRNA) synthesis. In this review, the known changes in the profile of DNA methylation as a factor affecting obesity and its complications are described. PMID:25531701

  9. Apoptosis and DNA Methylation

    Directory of Open Access Journals (Sweden)

    Richard R. Meehan

    2011-04-01

    Full Text Available Epigenetic mechanisms assist in maintaining gene expression patterns and cellular properties in developing and adult tissues. The molecular pathology of disease states frequently includes perturbation of DNA and histone methylation patterns, which can activate apoptotic pathways associated with maintenance of genome integrity. This perspective focuses on the pathways linking DNA methyltransferases and methyl-CpG binding proteins to apoptosis, and includes new bioinformatic analyses to characterize the evolutionary origin of two G/T mismatch-specific thymine DNA glycosylases, MBD4 and TDG.

  10. Spatial trends of polybrominated diphenyl ether (PBDE) congeners

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spatial trends of polybrominated diphenyl ether (PBDE) congeners were analyzed in young of the year bluefish collected along the U.S. Atlantic coastline from...

  11. The complicated ethers of glycerin and its functional derivatives

    International Nuclear Information System (INIS)

    The glycerides are complicated ethers of glycerin and fat acids. The glycerides call on incoming in their mixture remains of acids. The glycerides formed by palmitic acid have the name-palmitin, by stearine acids-stearins and etc

  12. Catalytic rearrangement of the chloroallyl ethers of p-cresol

    International Nuclear Information System (INIS)

    The rearrangement of a series of p-cresol ethers (β- and γ-chloro-, βγ- and βγ,γ-trichloroallyl), catalyzed by boron trifluoride etherate, was studied. Increase in the number of chlorine atoms in the allyl unit of the ether hinders the rearrangement, and its mechanism changes in the investigated series of ethers from intramolecular [3,3]-sigmatropic (with inversion of the allyl unit) to intermolecular, which corresponds to electrophilic substitution in the aromatic ring (without inversion). The presence of the chlorine atom at the β position of the allyl unit promotes rearrangement by a concerted intramolecular mechanism, while a chlorine atom at the γ position promotes rearrangement by an intermolecular stage mechanism. Two chlorine atoms at the γ position give rise mainly to the intermolecular rearrangement path

  13. Evaluation of crystallization kinetics of poly (ether-ketone-ketone and poly (ether-ether-ketone by DSC

    Directory of Open Access Journals (Sweden)

    Gibran da Cunha Vasconcelos

    2010-08-01

    Full Text Available The poly (aryl ether ketones are used as matrices in advanced composites with high performance due to its high thermal stability, excellent environmental performance and superior mechanical properties. Most of the physical, mechanical and thermodynamic properties of semi-crystalline polymers depend on the degree of crystallinity and morphology of the crystalline regions. Thus, a study on the crystallization process promotes a good prediction of how the manufacturing parameters affect the developed structure, and the properties of the final product. The objective of this work was to evaluate the thermoplastics polymers PEKK e PEEK by DSC, aiming to obtain the relationship between kinetics, content, nucleation and geometry of the crystalline phases, according to the parameters of the Avrami and Kissinger models. The analysis of the Avrami exponents obtained for the studied polymers indicates that both showed the formation of crystalline phases with heterogeneous nucleation and growth geometry of the type sticks or discs, depending on the cooling conditions. It was also found that the PEEK has a higher crystallinity than PEKK.

  14. Marine Sponge Dysidea herbacea revisited: Another Brominated Diphenyl Ether

    Directory of Open Access Journals (Sweden)

    Bruce F. Bowden

    2005-03-01

    Full Text Available Abstract: A pentabrominated phenolic diphenyl ether (1 that has not previously been reported from marine sources has been isolated from Dysidea herbacea collected at Pelorus Island, Great Barrier Reef, Australia. The structure was determined by comparison of NMR data with those of known structurally-related metabolites. NMR spectral assignments for (1 are discussed in context with those of three previously reported isomeric pentabrominated phenolic diphenyl ethers.

  15. Interpretation of the supraluminous neutrinos by a theory of ether

    OpenAIRE

    Delort, Thierry

    2011-01-01

    We exposed between the years 2000 to 2011 a very general theory of Ether, giving an interpretation of all the main experiments connected to Special and General Relativity and Cosmology. This theory of Ether was most of time even not considered, because it was contrary to Special Relativity. But a French team of physicists (led by Dario Autiero) recently realized an experiment, whose the result was contrary to Special Relativity, because it implied that a particle could go faster that the ligh...

  16. Interpretation of the Opera's experiment by a Theory of ether

    OpenAIRE

    Delort, Thierry

    2011-01-01

    5 pages We exposed between the years 2000 to 2011 a very general theory of Ether, giving an interpretation of all the main experiments connected to Special and General Relativity and Cosmology. This theory of Ether was most of time even not considered, because it was contrary to Special Relativity. But a French team of physicists (led by Dario Autiero) recently realized an experiment (Opera's experiment), whose the result was contrary to Special Relativity, because it implied that a partic...

  17. Highly efficient palladium-catalyzed hydrostannation of ethyl ethynyl ether

    OpenAIRE

    Andrews, Ian P.; Kwon, Ohyun

    2008-01-01

    The palladium-catalyzed hydrostannation of acetylenes is widely exploited in organic synthesis as a means of forming vinyl stannanes for use in palladium-catalyzed cross-coupling reactions. Application of this methodology to ethyl ethynyl ether results in an enol ether that is challenging to isolate from the crude reaction mixture because of incompatibility with typical silica gel chromatography. Reported here is a highly efficient procedure for the palladium-catalyzed hydrostannation of ethy...

  18. DNA Methylation and Cancer Diagnosis

    Directory of Open Access Journals (Sweden)

    Jérôme Torrisani

    2013-07-01

    Full Text Available DNA methylation is a major epigenetic modification that is strongly involved in the physiological control of genome expression. DNA methylation patterns are largely modified in cancer cells and can therefore be used to distinguish cancer cells from normal tissues. This review describes the main technologies available for the detection and the discovery of aberrantly methylated DNA patterns. It also presents the different sources of biological samples suitable for DNA methylation studies. We discuss the interest and perspectives on the use of DNA methylation measurements for cancer diagnosis through examples of methylated genes commonly documented in the literature. The discussion leads to our consideration for why DNA methylation is not commonly used in clinical practice through an examination of the main requirements that constitute a reliable biomarker. Finally, we describe the main DNA methylation inhibitors currently used in clinical trials and those that exhibit promising results.

  19. Methylated β-Cyclodextrins

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Madsen, Jens Christian;

    2011-01-01

    groups at O2 promote complexation by extending the hydrophobic cavity. Like in the case of 2-hydroxypropylated cyclodextrins, the methyl substituents cause an increased release of ordered water from the hydration shell of the bile salts, resulting in a strong increase in both the enthalpy and the entropy...

  20. A local-ether model of propagation of electromagnetic wave

    International Nuclear Information System (INIS)

    It is pointed out that the classical propagation model can be in accord with the Sagnac effect due to earth's rotational and orbital motions in the high-precision GPS (global positioning system) and interplanetary radar, if the reference frame of the classical propagation medium is endowed with a switchability according to the location of the wave. Accordingly, it is postulated that, as in the obsolete theory, electromagnetic waves propagate via a medium like the ether. However, the ether is not universal. It is proposed that in the region under sufficient influence of the gravity due to the earth, the sun, or another celestial body, there forms a local ether, which in turn is stationary with respect to the gravitational potential of the respective body. For earthbound and interplanetary propagation, the medium is stationary in a geocentric and a heliocentric inertial frame, respectively. An electromagnetic wave propagates at a constant speed with respect to the associated local ether, independent of the motions of source and receiver. Based on this local-ether model of wave propagation, a wide variety of earthbound, interplanetary, and interstellar propagation phenomena are accounted for. Strong evidence of this new classical model is its consistent account of the Sagnac effect due to earth's motions among GPS, the intercontinental microwave link, and the interplanetary radar. Moreover, as examined within the present precision, this model is still in accord with the Michelson-Morley experiment. To test the local-ether propagation model, a one-way-link rotor experiment is proposed. (orig.)

  1. Adsorption of rare earths with crown ether adsorbents

    International Nuclear Information System (INIS)

    Crown ether - phosphotungstic acid (PW) and crown ether -phosphomolybdic acid (PMo) precipitates, and also the granular entrapped crown ether - PMo (or PW) in polyacrylamide, were prepared and applied as adsorbents for rare earth metal ions. Adsorbents containing 15-crown-5, such as 15-crown-5 - PMo, were better adsorbents than the other crown ether precipitates. The adsorption capacity of 15-crown-5 - PMo for Eu3+ was determined and corresponded to about 0.166 mmol of Eu3+ per gram of the absorbent. The effects of pH and metal ion concentration on adsorption were also investigated. Crown ether - PMo (or PW) precipitates underwent hydrolysis at pH >= 1, but the granular entrapped crown ether - PMo (or PW) - polyacrylamide adsorbents were not hydrolysed at pH >= 1. The adsorption of individual rare earth ions with 15-crown-5 - PMo - polyacrylamide showed that Tb3+, Nd3+, Eu3+ and Gd3+ were readily adsorbed, but adsorption was difficult for Ce4+, Sm3+ and Dy3+. (author)

  2. Event extraction for DNA methylation

    OpenAIRE

    Ohta Tomoko; Pyysalo Sampo; Miwa Makoto; Tsujii Jun’ichi

    2011-01-01

    Abstract Background We consider the task of automatically extracting DNA methylation events from the biomedical domain literature. DNA methylation is a key mechanism of epigenetic control of gene expression and implicated in many cancers, but there has been little study of automatic information extraction for DNA methylation. Results We present an annotation scheme for DNA methylation following the representation of the BioNLP shared task on event extraction, select a set of 200 abstracts inc...

  3. Review on Modification of Sulfonated Poly (-ether-ether-ketone Membranes Used as Proton Exchange Membranes

    Directory of Open Access Journals (Sweden)

    Xiaomin GAO

    2015-11-01

    Full Text Available The proton exchange membrane fuel cell (PEMFC is a type of modern power, but the traditional proton exchange membranes (PEM of PEMFC are limited by high methanol permeability and water uptake. Poly-ether-ether-ketone (PEEK is a widely used thermoplastic with good cost-effective property. Sulfonated poly (-ether-ether-ketone (SPEEK has high electric conductivity and low methanol permeability, as well as comprehensive property, which is expected to be used as PEMs. However, the proton exchange ability, methanol resistance, mechanical property and thermal stability of SPEEK are closely related to the degree of sulfonation (DS of SPEEK membranes. Additionally, the proton conductivity, methanol permeability, and stability of SPEEK membranes applied in various conditions need to be further improved. In this paper, the research into modification of SPEEK membranes made by SPEEK and other polymers, inorganic materials are introduced. The properties and modification situation of the SPEEK and the composite membranes, as well as the advantages and disadvantages of membranes prepared by different materials are summarized. From the results we know that, the methanol permeability of SPEEK/PES-C membranes is within the order of magnitude, 10-7cm2/s. The proton conductivity of the SPPESK/SPEEK blend membrane reaches 0.212 S cm-1 at 80 °C. The cross-linked SPEEK membranes have raised thermal and dimensional stability. The non-solvent caused aggregation of the SPEEK ionomers. The proton conductivity of SPEEK/50%BMIMPF6/4.6PA membrane maintains stable as 2.0 x 10-2S cm-1 after 600 h at 160 °C. Incorporation of aligned CNT into SPEEK increases the proton conductivity and reduces the methanol permeability of the composite membranes. The PANI improves the hydrothermal stability. More proton transfer sites lead to a more compact structure in the composite membranes. According to the results, the proton exchange capacity, water uptake, and conductivity of

  4. Protein methylation in pea chloroplasts

    International Nuclear Information System (INIS)

    The methylation of chloroplast proteins has been investigated by incubating intact pea (Pisum sativum) chloroplasts with [3H-methyl]-S-adenosylmethionine. Incubation in the light increases the amount of methylation in both the thylakoid and stromal fractions. Numerous thylakoid proteins serve as substrates for the methyltransfer reactions. Three of these thylakoid proteins are methylated to a significantly greater extent in the light than in the dark. The primary stromal polypeptide methylated is the large subunit of ribulose bisphosphate carboxylase/oxygenase. One other stromal polypeptide is also methylated much more in the light than in the dark. Two distinct types of protein methylation occur. One methylinkage is stable to basic conditions whereas a second type is base labile. The base-stable linkage is indicative of N-methylation of amino acid residues while base-lability is suggestive of carboxymethylation of amino acid residues. Labeling in the light increases the percentage of methylation that is base labile in the thylakoid fraction while no difference is observed in the amount of base-labile methylations in light-labeled and dark-labeled stromal proteins. Also suggestive of carboxymethylation is the detection of volatile [3H]methyl radioactivity which increases during the labeling period and is greater in chloroplasts labeled in the light as opposed to being labeled in the dark; this implies in vivo turnover of the [3H]methyl group

  5. Conversion of dimethyl ether on zeolite catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Abramova, A.V.; Kulumbegov, R.V.; Khadzhiev, S.N. [Russian Academy of Sciences, Moscow (Russian Federation). A.V. Topchiev Inst. of Petrochemical Synthesis

    2006-07-01

    Catalytic conversion of dimethyl ether to hydrocarbons was investigated using zeolite catalyst ZSM-5 type. 2% MexOy - 60% HZVM(analogue of ZSM-5)/Al{sub 2}O{sub 3}, (Me = Zn, Ga, Fe, Co, V, Ni) catalyst samples have been obtained. The reaction was carried out in a fixed bed reaction set-up at 350-400 C, pressure 3 MPa, gas mix (% vol.): 24 DME, 76 N{sub 2}, WHSV=1300 l/l-{sub kat.}h. Most effective catalysts of DME conversion are pentasil based catalysts with promoter metals zinc, iron and cobalt by totality DME-conversion, gas and liquid hydrocarbon selectivity, ethylene and propylene content in gas. The best work temperatures are 350 and 375 C, thereupon increasing of temperature to 400 C leads to considerable growth of methane in hydrocarbon gas. Liquid hydrocarbons have high content of aromatics and iso-paraffins. Liquid hydrocarbon product is characterized by high octane number (RON) 90-98. (orig.)

  6. Radiation induced crosslinking of cellulose ethers

    International Nuclear Information System (INIS)

    The effects of high-energy radiation on four ethers of cellulose: carboxymethyl (CMC); hydroxypropyl (HPC), hydroxyethyl (HEC) and methylcellulose (MC) were investigated. Polymers are irradiated in solid state and in aqueous solutions at various concentrations. Degree of substitution (DS) of the derivatives, the concentration of their aqueous solutions and irradiation conditions had a significant impact on the obtained products. Irradiation of polymers in solid state and in diluted aqueous solutions resulted in their degradation. However, it was found that for concentrated solutions gel formation occurred. Paste-like form of the initial material, when water plasticizes the bulk of polymer as well as the high dose rate, what prevents oxygen penetration of the polymer during irradiation, have been found favourable for hydrogel formation. Up to 95% of gel fraction was obtained from solutions of CMC with concentration over 50% irradiated by γ-rays or electron beam. It was pointed out that the ability to the formation of the three-dimensional network is related to the DS of anhydroglucose units and a type of chemical group introduced to main chain of cellulose. Produced hydrogels swelled markedly in water. Despite of the crosslinked structure they underwent degradation by the action of cellulase enzyme or microorganisms from compost, and can be included into the group of biodegradable materials. (author)

  7. Explosion and detonation characteristics of dimethyl ether.

    Science.gov (United States)

    Mogi, Toshio; Horiguchi, Sadashige

    2009-05-15

    In this study, the explosion and detonation characteristics of dimethyl ether (DME) were experimentally investigated. A spherical pressure vessel with an internal volume of 180L was used as the explosion vessel. Therefore, tubes 10m in length with internal diameters of 25mm and 50mm were used as detonation tubes. In addition, we compared the characteristics of DME with those of propane since DME is considered as a substitute fuel for liquid petroleum gas (LPG). At room temperature and atmospheric pressure, the maximum explosive pressure increased tenfold. The explosion index (K(G) values), an indicator of the intensity of an explosion, was larger than that of propane, indicating that the explosion was intense. No experimental study has been conducted on the detonation behavior of DME so far, but this research confirmed a transition to detonation. The detonation characteristics were similar to the characteristics of the Chapman-Jouguet detonation, and the concentration range for detonation was from 5.5% to 9.0%. PMID:18774641

  8. Nanotextured Morphology of Poly(methyl methacrylate) and Ultraviolet Curable Poly(urethane acrylate) Blends via Phase Separation

    OpenAIRE

    Ju-Hyung Kim; Kim, Joon H.; Soonmin Seo

    2015-01-01

    Domain structures of spin-coated immiscible poly(methyl methacrylate) (PMMA) and ultraviolet (UV) curable poly(urethane acrylate) (PUA) blends were studied using atomic force microscopy (AFM). Spin casting the PMMA/PUA blends in propylene glycol monomethyl ether acetate (PGMEA) was accompanied with phase separation, and PUA was subsequently cross-linked under UV radiation. Selective dissolution of PMMA in the phase-separated films was feasible using tetrahydrofuran (THF) solvent after the UV ...

  9. 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)

  10. 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.

  11. Electrical conductivity of sulfonated poly(ether ether ketone) based composite membranes containing sulfonated polyhedral oligosilsesquioxane

    Science.gov (United States)

    Celso, Fabricio; Mikhailenko, Serguei D.; Rodrigues, Marco A. S.; Mauler, Raquel S.; Kaliaguine, Serge

    2016-02-01

    Composite proton exchange membranes (PEMs) intended for fuel cell applications were prepared by embedding of various amounts of dispersed tri-sulfonic acid ethyl POSS (S-Et-POSS) and tri-sulfonic acid butyl POSS (S-Bu-POSS) in thin films of sulfonated poly ether-ether ketone. The electrical properties of the PEMs were studied by Impedance spectroscopy and it was found that their conductivity σ changes with the filler content following a curve with a maximum. The water uptake of these PEMs showed the same dependence. The investigation of initial isolated S-POSS substances revealed the properties of typical electrolytes, which however in both cases possessed low conductivities of 1. 17 × 10-5 S cm-1 (S-Et-POSS) and 3.52 × 10-5 S cm-1 (S-Bu-POSS). At the same time, the insoluble in water S-POSS was found forming highly conductive interface layer when wetted with liquid water and hence producing a strong positive impact on the conductivity of the composite PEM. Electrical properties of the composites were analysed within the frameworks of effective medium theory and bounding models, allowing to evaluate analytically the range of possible conductivity values. It was found that these approaches produced quite good approximation of the experimental data and constituted a fair basis for interpretation of the observed relationship.

  12. The Effects of Sulfonated Poly(ether ether ketone Ion Exchange Preparation Conditions on Membrane Properties

    Directory of Open Access Journals (Sweden)

    Rebecca S. L. Yee

    2013-08-01

    Full Text Available A low cost cation exchange membrane to be used in a specific bioelectrochemical system has been developed using poly(ether ether ketone (PEEK. This material is presented as an alternative to current commercial ion exchange membranes that have been primarily designed for fuel cell applications. To increase the hydrophilicity and ion transport of the PEEK material, charged groups are introduced through sulfonation. The effect of sulfonation and casting conditions on membrane performance has been systematically determined by producing a series of membranes synthesized over an array of reaction and casting conditions. Optimal reaction and casting conditions for producing SPEEK ion exchange membranes with appropriate performance characteristics have been established by this uniquely systematic experimental series. Membrane materials were characterized by ion exchange capacity, water uptake, swelling, potential difference and NMR analysis. Testing this extensive membranes series established that the most appropriate sulfonation conditions were 60 °C for 6 h. For mechanical stability and ease of handling, SPEEK membranes cast from solvent casting concentrations of 15%–25% with a resulting thickness of 30–50 µm were also found to be most suitable from the series of tested casting conditions. Drying conditions did not have any apparent impact on the measured parameters in this study. The conductivity of SPEEK membranes was found to be in the range of 10−3 S cm−1, which is suitable for use as a low cost membrane in the intended bioelectrochemical systems.

  13. STUDY ON SYNTHESIZING 9,9-BIS (METHOXYMETHYL) FLUORENE POLYPROPYLENE USED AS A NEW TYE OF ELECTRON DONOR FOR ZGLER-NATTA POLYPROPYLENE CATALYSTS%Ziegler-Natta催化剂内给电子体9,9-双(甲氧甲基)芴的合成新工艺

    Institute of Scientific and Technical Information of China (English)

    李小明; 余官能; 杨锦飞; 涂媛鸿; 许招会

    2012-01-01

    实验以芴、金属钠与氯甲基甲醚为原料两步合成了9,9-双(甲氧甲基)芴,包括制备芴二基钠及芴二基钠的烷基化反应.最佳合成工艺条件为:(1)制备芴二基钠:以二乙二醇二甲醚为溶剂,n(芴)∶n(钠)=1.0∶2.2,反应温度为65℃,反应时间为8.0h;(2)芴二基钠的烷基化反应:n(芴)∶n(氯甲基甲醚)=1.0∶2.4,反应温度为20℃,反应时间6.0h,在上述条件下,9,9-双(甲氧甲基)芴收率可达66.9%.%9, 9-Bis (methoxymethyl) fluorene (BMMF) , a new type of electron donor for Ziegler-Nat-ta polypropylene catalysts, was synthesized from fluorene, metal sodium and chloromethyl methyl e-ther, which included synthesis of fluorene disodium by reaction of fluorene with metallic sodium and successive methylation of fluorene disodium with chloromethyl methyl ether. The optimal reaction conditions were found as follows: (1) for synthesis of fluorene disodium, diethylene glycol dimethyle-ther was used as solvent, n(fluorene):n(metallic sodium) = 1:2. 2, the reaction temperature was 65 ℃ , the reaction time was 8.0 h; (2) for methylation reaction, n(fluorene): n(chloromethyl methyl ether) = 1: 2. 4, the reaction temperature was 20 ℃ , the reaction time was 6. 0 h. Under above optimal conditions, the yield of BMMF could be up to 66. 9%.

  14. Methylation in hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Regina M. Santella

    2007-02-01

    Full Text Available

    The development of HCC is a complex, multistep, multistage process. The molecular pathogenesis of HCC appears to involve multiple genetic aberrations in the molecular control of hepatocyte proliferation, differentiation and death and the maintenance of genomic integrity. This process is influenced by the cumulative activation and inactivation of oncogenes, tumor suppressor genes and other genes. p53, a tumor suppressor gene, is the most frequently mutated gene in human cancers. There is also a striking sequence specific binding and induction of mutations by AFB1 at codon 249 of p53 in HCC.

    Epigenetic alterations are also involved in cancer development and progression. Methylation of promoter CpG islands is associated with inhibition of transcriptional initiation and permanent silencing of downstream genes.

    It is now known that most important tumor suppressor genes are inactivated, not only by mutations and deletions but also by promoter methylation. Several studies indicated that p16, p15, RASSF1A, MGMT, and GSTP1 promoter hypermethylation are prevalent in HCC. In addition, geographic variation in the methylation status of tumor DNA indicates that environmental factors may influence the frequent and concordant degree of hypermethylation in multiple genes in HCC and that epigeneticenvironmental interactions may be involved in hepatocarcinogenesis. We have found significant relationships between promoter methylation and AFB1-DNA adducts confirming the impact of environmental exposures on gene methylation.

    DNA isolated from serum or plasma of cancer patients frequently contains the same genetic and

  15. Synthesis and application of chloromethylated polystyrene modified with 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new sorbent for the on-line preconcentration and determination of copper in water, soil, and food samples by FAAS

    International Nuclear Information System (INIS)

    Highlights: → This paper is the first report on the use of PS-PPDOT resin in the SPE studies. → The proposed adsorbent is highly selective for trace determination of copper. → The method is applicable for copper determination in water, soil, and food samples. - Abstract: In this paper, we report a simple and sensitive on-line solid phase extraction system for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry (FAAS). This method is based upon the on-line retention of copper at pH 5.0 on a minicolumn packed with chloromethylated polystyrene modified by 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new solid-phase extraction (SPE) sorbent. The retained Cu(II) ions were eluted with 1.0 M HNO3, and transported directly to FAAS for determination. Several chemical and flow variables were studied and optimized for a quantitative preconcentration and determination of copper(II). At the optimized conditions, for preconcentration of 10.0 mL of a sample solution, a linear calibration graph was obtained over the concentration range of 3.00-120.0 μg L-1 for Cu(II). The limit of detection (3σ), limit of quantification (10σ), and enrichment factor are 0.56 μg L-1, 2.0 μg L-1 and 41, respectively. The relative standard deviation (n = 6) at 20 μg L-1 of Cu(II) is 2.0%. This method could be applied for determination of trace amounts of Cu(II) in water, soil, and food samples with satisfactory results.

  16. Synthesis and application of chloromethylated polystyrene modified with 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new sorbent for the on-line preconcentration and determination of copper in water, soil, and food samples by FAAS

    Energy Technology Data Exchange (ETDEWEB)

    Chamjangali, Mansour Arab, E-mail: marab@shahroodut.ac.ir [College of Chemistry, Shahrood University of Technology, P.O. Box 36155-316, Shahrood (Iran, Islamic Republic of); Bagherian, Ghadamali; Mokhlesian, Ali; Bahramian, Bahram [College of Chemistry, Shahrood University of Technology, P.O. Box 36155-316, Shahrood (Iran, Islamic Republic of)

    2011-09-15

    Highlights: {yields} This paper is the first report on the use of PS-PPDOT resin in the SPE studies. {yields} The proposed adsorbent is highly selective for trace determination of copper. {yields} The method is applicable for copper determination in water, soil, and food samples. - Abstract: In this paper, we report a simple and sensitive on-line solid phase extraction system for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry (FAAS). This method is based upon the on-line retention of copper at pH 5.0 on a minicolumn packed with chloromethylated polystyrene modified by 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new solid-phase extraction (SPE) sorbent. The retained Cu(II) ions were eluted with 1.0 M HNO{sub 3}, and transported directly to FAAS for determination. Several chemical and flow variables were studied and optimized for a quantitative preconcentration and determination of copper(II). At the optimized conditions, for preconcentration of 10.0 mL of a sample solution, a linear calibration graph was obtained over the concentration range of 3.00-120.0 {mu}g L{sup -1} for Cu(II). The limit of detection (3{sigma}), limit of quantification (10{sigma}), and enrichment factor are 0.56 {mu}g L{sup -1}, 2.0 {mu}g L{sup -1} and 41, respectively. The relative standard deviation (n = 6) at 20 {mu}g L{sup -1} of Cu(II) is 2.0%. This method could be applied for determination of trace amounts of Cu(II) in water, soil, and food samples with satisfactory results.

  17. Chemistry of Pyrones, Part 5: New Crown Ether and Podand Derivatives of 3,5-Bis(bromomethyl-2,6-diphenyl-4H-pyran-4-one

    Directory of Open Access Journals (Sweden)

    Alireza Banaei

    2001-08-01

    Full Text Available New podand and crown ether derivatives of 3,5-disubstituted 4H-pyran-4-one (8-11 were prepared by the nucleophilic substitution reaction of 3,5-bis(bromomethyl-2,6-diphenyl-4H-pyran-4-one with o-nitrophenol, 8-hydroxyquinoline, 2-hydroxymethyl pyridine and triethyleneglycol, respectively. The yield of 3,5-bis[(2-formylphenoxy methyl]-2,6-diphenyl-4H-pyran-4-one has been improved by modification of our previous method using NaOH instead of Et3N.

  18. Tandem Bond-Forming Reactions of 1-Alkynyl Ethers.

    Science.gov (United States)

    Minehan, Thomas G

    2016-06-21

    Electron-rich alkynes, such as ynamines, ynamides, and ynol ethers, are functional groups that possess significant potential in organic chemistry for the formation of carbon-carbon bonds. While the synthetic utility of ynamides has recently been expanded considerably, 1-alkynyl ethers, which possess many of the reactivity features of ynamides, have traditionally been far less investigated because of concerns about their stability. Like ynamides, ynol ethers are relatively unhindered to approach by functional groups present in the same or different molecules because of their linear geometry, and they can potentially form up to four new bonds in a single transformation. Ynol ethers also possess unique reactivity features that make them complementary to ynamides. Research over the past decade has shown that ynol ethers formed in situ from stable precursors engage in a variety of useful carbon-carbon bond-forming processes. Upon formation at -78 °C, allyl alkynyl ethers undergo a rapid [3,3]-sigmatropic rearrangement to form allyl ketene intermediates, which may be trapped with alcohol or amine nucleophiles to form γ,δ-unsaturated carboxylic acid derivatives. The process is stereospecific, takes place in minutes at cryogenic temperatures, and affords products containing (quaternary) stereogenic carbon atoms. Trapping of the intermediate allyl ketene with carbonyl compounds, epoxides, or oxetanes instead leads to complex α-functionalized β-, γ-, or δ-lactones, respectively. [3,3]-Sigmatropic rearrangement of benzyl alkynyl ethers also takes place at temperatures ranging from -78 to 60 °C to afford substituted 2-indanones via intramolecular carbocyclization of the ketene intermediate. tert-Butyl alkynyl ethers containing pendant di- and trisubstituted alkenes and enol ethers are stable to chromatographic isolation and undergo a retro-ene/[2 + 2] cycloaddition reaction upon mild thermolysis (90 °C) to afford cis-fused cyclobutanones and donor

  19. Influence of Cellulose Ethers on Hydration Products of Portland Cement

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; OU Zhihua; JIAN Shouwei; XU Rulin

    2011-01-01

    Cellulose ethers are widely used to mortar formulations, and it is significant to understand the interaction between cellulose ethers and cement pastes. FT-IR spectra, thermal analysis and SEM are used to investigate hydration products in the cement pastes modified by HEMC and HPMC in this article. The results show that the hydration products in modified cement pastes were finally identical with those in the unmodified cement paste, but the major hydration products, such as CH (calcium hydroxide), ettringite and C-S-H, appeared later in the modified cement pastes than in the unmodified cement paste. The cellulose ethers decrease the outer products and increase inner products of C-S-H gels. Compared to unmodified cement pastes, no new products are found in the modified cement pastes in the present experiment. The HEMC and HPMC investigation shows almost the same influence on the hydration products of Portland cement.

  20. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must...

  1. Aberrant methylation patterns in cancer

    OpenAIRE

    Hudler, Petra; Videtič, Alja

    2016-01-01

    Epigenetic mechanisms, such as DNA methylation, DNA hydroxymethylation, post-translational modifications (PTMs) of histone proteins affecting nucleosome remodelling, and regulation by small and large non-coding RNAs (ncRNAs) work in concert with cis and trans acting elements to drive appropriate gene expression. Advances in detection methods and development of dedicated platforms and methylation arrays resulted in an explo - sion of information on aberrantly methylated sequences linking devia...

  2. Novel Unsaturated Sucrose Ethers and Their Application as Monomers

    Directory of Open Access Journals (Sweden)

    Maria T. Barros

    2007-03-01

    Full Text Available Novel unsaturated ethers were synthesised in good yields starting from sucrose,using a two-step mild and efficient procedure based on the Gassman method, whichconsists in forming a vinyl group by the elimination of ethanol from mixed acetals withtrimethylsilyl trifluoromethanesulfonate in the presence of alkyl amines. Mixed acetals arereadily obtained from the corresponding alcohols and ethyl vinyl ether, using an acidiccatalyst. Conventional etherification involving a primary halide was also examined. Themonomers thus obtained were successfully polymerised by a free radical mechanism,yielding unbranched linear and soluble polymers with pending sucrose moieties, and someof their physical properties were determined.

  3. Effect of Parameters on Oxychlorination of Tert-Butyl Ethers

    OpenAIRE

    Gaca, Jerzy; Gackowska, Alicja; Belt, Natalia

    2008-01-01

    The effect of concentration, molar ratios of reagents, pH, and temperature on formation of chloro-organic products in reaction of tert-butyl ethers with chloride ions and hydrogen peroxide has been determined. A significant effect of Cl− ions and H2O2 molar ratios on the rate of chloro-organic product formation has been observed. Studies on oxychlorination of tert-butylethyl ether (ETBE) at pH 7, 3.5, and 2.5 have been carried out. It was found that introduction of hydronium ions into the rea...

  4. Concise synthesis of ether analogues of lysobisphosphatidic acid.

    Science.gov (United States)

    Jiang, Guowei; Xu, Yong; Falguières, Thomas; Gruenberg, Jean; Prestwich, Glenn D

    2005-09-01

    We describe a versatile, efficient method for the preparation of ether analogues of (S,S)-lysobisphosphatidic acid (LBPA) and its enantiomer from (S)-solketal. Phosphorylation of a protected sn-2-O-octadecenyl glyceryl ether with 2-cyanoethyl bis-N,N-diisopropylamino phosphine and subsequent deprotection generated the bisether LBPA analogues. By simply changing the sequence of deprotection steps, we obtained the (R,R)- and (S,S)-enantiomers of 2,2'-bisether LBPA. An ELISA assay with anti-LBPA monoclonal antibodies showed that the bisether LBPAs were recognized with the same affinity as the natural 2,2'-bisoleolyl LBPA. [reaction: see text] PMID:16119911

  5. Mutual solubility in the system uranyl trichloroacetate--water--diethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Vdovenko, V.M.; Baluev, A.V.; Suglobova, I.G.

    1975-01-01

    A study was made of mutual solubility in the system uranyl trichloroacetate--water--diethyl ether at 25/sup 0/C. It was found that the solubility of the salt in ether and the composition of the lower phase depend on the water content of the ternary system. On the basis of ir spectra of ether solutions of uranyl trichloroacetate in the presence of semiheavy water (HDO) the structure of the hydration envelope of the complex in diethyl ether was established.

  6. Effect of Backbone Structure on Membrane Properties for Poly(arylene ether) Random and Multiblock Copolymers

    OpenAIRE

    Rowlett, Jarrett Robert

    2014-01-01

    Poly(arylene ether)s are a well-established class of thermoplastics that are known for their mechanical toughness, thermal stability, and fabrication into membranes. These materials can undergo a myriad of modifications including backbone structure variability, sulfonation, and crosslinking. In this dissertation, structure-property relationships are considered for poly(arylene ether)s with regard to membrane applications for proton exchange and gas separation membranes. All of the proton...

  7. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted...

  8. Carboxymethyl ethers of cellulose obtained from secondary products of fine-stapled cotton

    International Nuclear Information System (INIS)

    This article is devoted to synthesis and properties of carboxymethyl ethers of cellulose obtained from secondary products of fine-stapled cotton. The investigation of extraction conditions of cellulose on the quality of carboxymethyl ethers of cellulose is conducted. The qualitative characteristics of cotton cellulose are considered. The synthesis of carboxymethyl ethers of cellulose from obtained cellulose is described.

  9. Effect of beta-adrenoceptor blockers on human ether-a-go-go-related gene (HERG) potassium channels

    DEFF Research Database (Denmark)

    Dupuis, Delphine S; Klaerke, Dan A; Olesen, Søren-Peter

    2005-01-01

    Patients with congenital long QT syndrome may develop arrhythmias under conditions of increased sympathetic tone. We have addressed whether some of the beta-adrenoceptor blockers commonly used to prevent the development of these arrhythmias could per se block the cardiac HERG (Human Ether....... These data showed that HERG blockade by beta-adrenoceptor blockers occurred only at high micromolar concentrations, which are significantly above the recently established safe margin of 100 (Redfern et al., 2003).......-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol hydrochloride) blocked the HERG channel with similar affinity, whereas the beta1-receptor antagonists metoprolol and atenolol showed weak effects. Further, the four compounds blocked HERG channels expressed in a mammalian HEK293 cell line...

  10. Antiproliferative constituents from umbelliferae plants. V. A new furanocoumarin and falcarindiol furanocoumarin ethers from the root of Angelica japonica.

    Science.gov (United States)

    Fujioka, T; Furumi, K; Fujii, H; Okabe, H; Mihashi, K; Nakano, Y; Matsunaga, H; Katano, M; Mori, M

    1999-01-01

    The CHCl3 extract of the root of Angelica japonica showed high inhibitory activity against human gastric adenocarcinoma (MK-1) cell growth. From this extract, a new furanocoumarin named japoangelone and four furanocoumarin ethers of falcarindiol, named japoangelols A-D, were isolated together with caffeic acid methyl ester, four polyacetylenic compounds (panaxynol, falcarindiol, 8-O-acetylfalcarindiol, and (9Z)-1,9-heptadecadiene-4,6-diyne-3,8,11-triol), eight coumarins (osthol, isoimperatorin, scopoletin, byakangelicin, xanthotoxin, bergapten, oxypeucedanin methanolate, and oxypeucedanin hydrate), and two chromones (3'-O-acetylhamaudol, and hamaudol). The structures of the new isolates were determined based on spectral evidence. The ED50 of isolates against MK-1, HeLa, and B16F10 cell lines are reported. PMID:9987830

  11. Coordinated transcriptional regulation of the divinyl ether biosynthetic genes in tobacco by signal molecules related to defense.

    Science.gov (United States)

    Fammartino, Alessandro; Verdaguer, Bertrand; Fournier, Joëlle; Tamietti, Giacomo; Carbonne, Francis; Esquerré-Tugayé, Marie-Thérèse; Cardinale, Francesca

    2010-04-01

    In tobacco, 9-divinyl ethers (DVEs) produced by the lipoxygenase NtLOX1 and DVE synthase NtDES1 are important for full resistance to pathogens. In this work, the regulation of NtLOX1 and NtDES1 expression by signal molecules was investigated in LOX1 promoter-reporter transgenic plants and by RT-qPCR. Methyl jasmonate, ACC and elicitor were shown to coordinately trigger the DVE pathway. Induction was strongly attenuated in the presence of salicylic acid, which seems to act as a negative regulator of the 9-DVE biosynthetic enzymes. Our data suggest that, in tobacco, DVE biosynthesis is cross-regulated by jasmonates, and by other hormonal and signal molecules such as ethylene and SA. PMID:20137961

  12. 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. PMID:20715046

  13. Comparative Environmental Performance of Two-Diesel-Fuel Oxygenates: Dibutyl Maleate (DBM) and Triproplyene Glycol Monomethyl Ether (TGME)

    Energy Technology Data Exchange (ETDEWEB)

    Layton, D.W.; Marchetti, A.A.

    2001-10-01

    Many studies have shown that the addition of oxygen bearing compounds to diesel fuel can significantly reduce particulate emissions. To assist in the evaluation of the environmental performance of diesel-fuel oxygenates, we have implemented a suite of diagnostic models for simulating the transport of compounds released to air, water, and soils/groundwater as well as regional landscapes. As a means of studying the comparative performance of DBM and TGME, we conducted a series of simulations for selected environmental media. Benzene and methyl tertiary butyl ether (MTBE) were also addressed because they represent benchmark fuel-related compounds that have been the subject of extensive environmental measurements and modeling. The simulations showed that DBM and TGME are less mobile in soil because of reduced vapor-phase transport and increased retention on soil particles. The key distinction between these two oxygenates is that DBM is predicted to have a greater potential than TGME for aerobic biodegradation, based on chemical structure.

  14. Highly sensitive dimethyl ether gas sensor utilizing cataluminescence on nanosized MgO/In2O3

    International Nuclear Information System (INIS)

    A gaseous sensor was developed for the determination of dimethyl ether (DME) on the basis of its cataluminescence (CTL) emission on the surface of MgO/In2O3 composite (mass ratio = 1:2). The sensor exhibited high sensitivity and selectivity to DME at a temperature of 245 °C. Under the optimized experimental conditions, the linear range of CTL intensity versus DME concentration was 50–12 000 ppm with a limit of detection of 14 ppm (signal to noise (S/N) = 3). By selecting the appropriate ratio of MgO to In2O3 and the detecting wavelength, the CTL intensities of ether and ethanol could be reduced to 7.3% and 3.9% compared with that of DME. For other compounds, including carbon tetrachloride, formaldehyde, dimethyl sulfate and methyl acetate, etc, no emissions or only very weak ones were detected. The sensor was applied to analyze samples spiked with known concentrations of DME. The concentrations of DME in all samples were well quantified with satisfactory recoveries. (paper)

  15. Ultralow Oil-Fouling Heterogeneous Poly(ether sulfone) Ultrafiltration Membrane via Blending with Novel Amphiphilic Fluorinated Gradient Copolymers.

    Science.gov (United States)

    Zhang, Guangfa; Jiang, Jingxian; Zhang, Qinghua; Gao, Fan; Zhan, Xiaoli; Chen, Fengqiu

    2016-02-01

    A novel amphiphilic fluorinated gradient copolymer was prepared by semibatch reversible addition-fragmentation chain transfer (RAFT) method using poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate (TFOA) as monomers. The resultant amphiphilic copolymers were then incorporated into the poly(ether sulfone) (PES) to fabricate PES blend membranes via the non-solvent-induced phase separation method (NIPS). During the phase inversion process, both hydrophilic (PEGMA) and low surface energy (TFOA) segments significantly enriched on the membrane surface by surface segregation to form an amphiphilic surface, which was demonstrated by surface wetting properties and X-ray photoelectron spectroscopy (XPS) measurements. According to the filtration experiments of oil-in-water emulsion, the heterogeneous membranes exhibited superior oil-fouling resistant properties, that is, low flux decay (as low as 15.4%) and high flux recovery (almost 100%), compared to the pure PES membrane. The synergistic effect of fouling-resistant and fouling-release mechanisms was found to be responsible for the excellent antifouling capacities. The findings of this study offer a facile and robust strategy for fabricating ultralow oil-fouling membranes that might be used for effective oil/water separation. PMID:26780307

  16. Synthesis of Hydroxytyrosyl Alkyl Ethers from Olive Oil Waste Waters

    Directory of Open Access Journals (Sweden)

    Juan Fernández-Bolaños

    2009-05-01

    Full Text Available The preparation of a new type of derivatives of the naturally occurring antioxidant hydroxytyrosol is reported. Hydroxytyrosyl alkyl ethers were obtained in high yield by a three-step procedure starting from hydroxytyrosol isolated from olive oil waste waters. Preliminary results obtained by the Rancimat method have shown that these derivatives retain the high protective capacity of free hydroxytyrosol.

  17. Aqueous alkali metal hydroxide insoluble cellulose ether membrane

    Science.gov (United States)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1969-01-01

    A membrane that is insoluble in an aqueous alkali metal hydroxide medium is described. The membrane is a resin which is a water-soluble C2-C4 hydroxyalkyl cellulose ether polymer and an insolubilizing agent for controlled water sorption, a dialytic and electrodialytic membrane. It is particularly useful as a separator between electrodes or plates in an alkaline storage battery.

  18. Selected Methods of Dehalogenation of Polybrominated Diphenyl Ethers

    Czech Academy of Sciences Publication Activity Database

    Vajglová, Zuzana; Vychodilová, Hana; Křišťál, Jiří; Kaštánek, František; Jiřičný, Vladimír

    Frankfurt: DECHEMA, 2011, P05.04. ISBN N. [European Congress of Chemical Engineering /8./. Berlin (DE), 25.09.2011-29.09.2011] Institutional research plan: CEZ:AV0Z40720504 Keywords : polybrominated diphenyl ethers * concentrations * waste waters Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  19. Synthesis of Hydroxytyrosyl Alkyl Ethers from Olive Oil Waste Waters

    OpenAIRE

    2009-01-01

    The preparation of a new type of derivatives of the naturally occurring antioxidant hydroxytyrosol is reported. Hydroxytyrosyl alkyl ethers were obtained in high yield by a three-step procedure starting from hydroxytyrosol isolated from olive oil waste waters. Preliminary results obtained by the Rancimat method have shown that these derivatives retain the high protective capacity of free hydroxytyrosol.

  20. Allyl ethers of the 1-alkoxy-2,3-propandiol

    International Nuclear Information System (INIS)

    With the purpose of study of 1-alkoxy-2,3-propandiol allying reaction wasobtained their mono- and diallyl ethers by authors of this article. Theinitial 1-alkoxy-2,3-propandiol was synthesised from mono chlor-hydrin ofglycerin and alcoholates of alcohols of saturated line (C1-C5) and theirisomers

  1. Photodegradation of poly(ether sulphone). Part 2

    DEFF Research Database (Denmark)

    Norrman, K.; Krebs, Frederik C

    2004-01-01

    The photodegradation of poly(ether sulphone) (PES) was investigated systematically by time-of-flight SIMS (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS). The effect of varying the irradiation dose, wavelength and the atmosphere was studied along with mechanistic photooxidation studies using...

  2. Li-air batteries having ether-based electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Amine, Khalil; Curtiss, Larry A; Lu, Jun; Lau, Kah Chun; Zhang, Zhengcheng; Sun, Yang-Kook

    2015-03-03

    A lithium-air battery includes a cathode including a porous active carbon material, a separator, an anode including lithium, and an electrolyte including a lithium salt and polyalkylene glycol ether, where the porous active carbon material is free of a metal-based catalyst.

  3. 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 ...

  4. The ether lipid-deficient mouse: tracking down plasmalogen functions.

    Science.gov (United States)

    Gorgas, Karin; Teigler, Andre; Komljenovic, Dorde; Just, Wilhelm W

    2006-12-01

    Chemical and physico-chemical properties as well as physiological functions of major mammalian ether-linked glycerolipids, including plasmalogens were reviewed. Their chemical structures were described and their effect on membrane fluidity and membrane fusion discussed. The recent generation of mouse models with ether lipid deficiency offered the possibility to study ether lipid and particularly plasmalogen functions in vivo. Ether lipid-deficient mice revealed severe phenotypic alterations, including arrest of spermatogenesis, development of cataract and defects in central nervous system myelination. In several cell culture systems lack of plasmalogens impaired intracellular cholesterol distribution affecting plasma membrane functions and structural changes of ER and Golgi cisternae. Based on these phenotypic anomalies that were accurately described conclusions were drawn on putative functions of plasmalogens. These functions were related to cell-cell or cell-extracellular matrix interactions, formation of lipid raft microdomains and intracellular cholesterol homeostasis. There are several human disorders, such as Zellweger syndrome, rhizomelic chondrodysplasia punctata, Alzheimer's disease, Down syndrome, and Niemann-Pick type C disease that are distinguished by altered tissue plasmalogen concentrations. The role plasmalogens might play in the pathology of these disorders is discussed. PMID:17027098

  5. Synthesis of new indolyl crown ethers catalyzed with ferric hydrogensulfate

    Institute of Scientific and Technical Information of China (English)

    Hossein Eshghi; Mohammad Rahimizadeh; Zahra Bakhtiarpoor; Mehdi Pordel

    2012-01-01

    Efficient reaction of bis-indolyl podand with different aldehydes using Fe(HSO4)3 as catalyst to afford the corresponding new indolyl crown ethers is described.The structures of three distinct isomers have been optimized using HyperChem geometry optimizations.Also percentage of each isomer was obtained with 1H NMR spectroscopy.

  6. DNA methylation in metabolic disorders

    DEFF Research Database (Denmark)

    Barres, Romain; Zierath, Juleen R

    2011-01-01

    have provided evidence that environmental factors at all ages could modify DNA methylation in somatic tissues, which suggests that DNA methylation is a more dynamic process than previously appreciated. Because of the importance of lifestyle factors in metabolic disorders, DNA methylation provides...... a mechanism by which environmental factors, including diet and exercise, can modify genetic predisposition to disease. This article considers the current evidence that defines a role for DNA methylation in metabolic disorders.......DNA methylation is a major epigenetic modification that controls gene expression in physiologic and pathologic states. Metabolic diseases such as diabetes and obesity are associated with profound alterations in gene expression that are caused by genetic and environmental factors. Recent reports...

  7. Methods of DNA methylation detection

    Science.gov (United States)

    Maki, Wusi Chen (Inventor); Filanoski, Brian John (Inventor); Mishra, Nirankar (Inventor); Rastogi, Shiva (Inventor)

    2010-01-01

    The present invention provides for methods of DNA methylation detection. The present invention provides for methods of generating and detecting specific electronic signals that report the methylation status of targeted DNA molecules in biological samples.Two methods are described, direct and indirect detection of methylated DNA molecules in a nano transistor based device. In the direct detection, methylated target DNA molecules are captured on the sensing surface resulting in changes in the electrical properties of a nano transistor. These changes generate detectable electronic signals. In the indirect detection, antibody-DNA conjugates are used to identify methylated DNA molecules. RNA signal molecules are generated through an in vitro transcription process. These RNA molecules are captured on the sensing surface change the electrical properties of nano transistor thereby generating detectable electronic signals.

  8. Effect of Concentration of Catalyst (BF3-Diethyl Etherate on Synthesis of Polyester From Palm Fatty Acid Distillate (PFAD

    Directory of Open Access Journals (Sweden)

    Renita Manurung

    2013-10-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Palm Fatty Acid Distillate (PFAD can be used as raw material for synthesis polyester. The aim of this research is to synthesis of polyester and to determine the effect of concentration of catalyst on polymerization methyl ester PFAD. The esterification stage was done at temperature 70oC, reaction time 120 minute, reactant ratio 1:8 (PFAD: methanol, concentration of catalyst (H2SO4 1% (w/w PFAD; polymerization stage was done at temperature 126-132°C, polymerization reaction time 4 hours; variation of concentration of catalyst (BF3-diethyl etherate 0%, 6.9%, 9.2%, 11.5% (w/w methyl ester; and polyesterification stage was done at temperature 175-200 oC, reactant ratios (w/w 1:1 (polymerized ME : ethylene glycol, reaction time 4 hours and all of stage was stirred at 150 rpm. The results showed, in the esterification stage was obtained methyl ester with iodine value 77.29 g I2/100 g, viscosity 6.90 cP, density 859.91 kg/m3 and analysis by using GC-MS showed that the purity of methyl ester was 82.23% and molecular weight 267.97 g/mol. Decreasing in iodine value from 77.29 I2 g/100 g to 74.97-59.99 g I2/100 g indicated that the polymerization process had taken place. In polyesterification stage was obtained light brown colored

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

    OpenAIRE

    Vijayakumar Thulasi; Thundil Karrupa Raj Rajagopal; Nanthagopal Kasianantham

    2011-01-01

    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...

  10. DNA Methylation in Thyroid Tumorigenesis

    International Nuclear Information System (INIS)

    Thyroid cancer is the most common endocrine cancer with 1,690 deaths each year. There are four main types of which the papillary and follicular types together account for >90% followed by medullary cancers with 3% to 5% and anaplastic carcinomas making up <3%. Epigenetic events of DNA hypermethylation are emerging as promising molecular targets for cancer detection. Our immediate and long term goal is to identify DNA methylation markers for early detection of thyroid cancer. This pilot study comprised of 21 patients to include 11 papillary thyroid cancers (PTC), 2 follicular thyroid cancers (FTC), 5 normal thyroid cases, and 3 hyperthyroid cases. Aberrant promoter methylation was examined in 24 tumor suppressor genes using the methylation specific multiplex ligation-dependent probe amplification (MS-MLPA) assay and in the NIS gene using methylation-specific PCR (MSP). The frequently methylated genes were CASP8 (17/21), RASSF1 (16/21) and NIS (9/21). In the normal samples, CASP8, RASSF1 and NIS were methylated in 5/5, 4/5 and 1/5 respectively. In the hyperthyroid samples, CASP8, RASSF1 and NIS were methylated in 3/3, 2/3 and 1/3 respectively. In the thyroid cancers, CASP8, RASSF1, and NIS were methylated in 9/13, 10/13, and 7/13 respectively. CASP8, RASSF1 and NIS were also methylated in concurrently present normal thyroid tissue in 3/11, 4/11 and 3/11 matched thyroid cancer cases (matched for presence of both normal thyroid tissue and thyroid cancer), respectively. Our data suggests that aberrant methylation of CASP8, RASSF1, and NIS maybe an early change in thyroid tumorigenesis regardless of cell type

  11. 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.

  12. Comparative photophysical behaviour of naphthalene-linked crown ethers and aza crown ethers of varying cavity dimensions

    Indian Academy of Sciences (India)

    Subhodip Samanta; Pinki Saha Sardar; Shyam Sundar Maity; Anirban Pal; Maitrayee Basu Roy; Sanjib Ghosh

    2007-03-01

    A comparative time-resolved emission studies of several naphtho-crown ethers I-V, where metal ions can be complexed in a predetermined orientation with respect to the naphthalene (Naph) - plane and naphthalene-linked aza crown ethers (L1 and L2) have been presented. In both the systems, crown ethers and aza crown ethers, naphthalene fluorescence gets quenched. In the systems I to V, the quenching is mainly due to efficient spin-orbit coupling (SOC) leading to greater population of the lowest triplet state of naphthalene. This SOC depends on the orientation of the crown ring with respect to the Naph--plane. However, in the systems L1 and L2, the quenching is due to photoinduced electron transfer (PET) from nitrogen lone pair of the aza crown ring to naphthalene moiety and consequent exciplex formation. The results have been interpreted using the time-resolved emission studies of all the compounds in various solvents, their alkali metal ion complexes, and protonated ligands.

  13. 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.

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

    International Nuclear Information System (INIS)

    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®. • SPEEK exhibited one order lesser oxygen permeability than Nafion®. • Nafion® 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®. 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®, 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

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

    KAUST Repository

    Jalal, Taghreed A.

    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.

  16. New amphiphilic PEG-b-P(ester–ether) micelles as potential drug nanocarriers

    International Nuclear Information System (INIS)

    A range of diblock and triblock copolymers of dioxanone and methyl dioxanone (MeDX) were synthesized by ring-opening polymerization of dioxanone and MeDX initiated by hydroxyl-terminated PEG (MPEG) or di-amino-terminated PEG (Jeffamine®) as macroinitiator in the presence of Sn(Oct)2. The copolymers exhibit amphiphilic behavior in water forming core–shell micelles in the size range 120–300 nm as measured by DLS. DSC measurements exhibit only one melting transition for all copolymers and confirm that increasing MeDX content of the copolymers lead to decreasing crystalline character and hydrophobic–hydrophilic chain entanglement. Anti-inflammatory drug ketoprofen was successfully loaded into the hydrophobic core of the micelles. Various key parameters such as micelle size, drug entrapment efficiency and drug release, which are dependent on crystalline structure and biodegradability characteristics of the hydrophobic core, could effectively be controlled by varying the dioxanone/MeDX ratio of the (ester–ether) copolymer.

  17. New amphiphilic PEG-b-P(ester-ether) micelles as potential drug nanocarriers

    Energy Technology Data Exchange (ETDEWEB)

    Jeetah, Roubeena; Bhaw-Luximon, Archana; Jhurry, Dhanjay, E-mail: dhanjay.jhurry@gmail.com [University of Mauritius, ANDI Centre of Excellence for Biomedical and Biomaterials Research, MSIRI Building (Mauritius)

    2012-10-15

    A range of diblock and triblock copolymers of dioxanone and methyl dioxanone (MeDX) were synthesized by ring-opening polymerization of dioxanone and MeDX initiated by hydroxyl-terminated PEG (MPEG) or di-amino-terminated PEG (Jeffamine{sup Registered-Sign }) as macroinitiator in the presence of Sn(Oct){sub 2}. The copolymers exhibit amphiphilic behavior in water forming core-shell micelles in the size range 120-300 nm as measured by DLS. DSC measurements exhibit only one melting transition for all copolymers and confirm that increasing MeDX content of the copolymers lead to decreasing crystalline character and hydrophobic-hydrophilic chain entanglement. Anti-inflammatory drug ketoprofen was successfully loaded into the hydrophobic core of the micelles. Various key parameters such as micelle size, drug entrapment efficiency and drug release, which are dependent on crystalline structure and biodegradability characteristics of the hydrophobic core, could effectively be controlled by varying the dioxanone/MeDX ratio of the (ester-ether) copolymer.

  18. Polybrominated diphenyl ethers (PBDEs) and mercury in fish from lakes of the Tibetan Plateau.

    Science.gov (United States)

    Yang, Ruiqiang; Jing, Chuanyong; Zhang, Qinghua; Wang, Zhenhua; Wang, Yawei; Li, Yingming; Jiang, Guibin

    2011-04-01

    High mountains may act as cold traps for globally transported persistent organic pollutants (POPs) and mercury (Hg). In the present study, 60 fish samples were collected from eight alpine lakes across the Tibetan Plateau. Concentrations of polybrominated diphenyl ethers (PBDEs), total mercury (HgT) and methyl mercury (MeHg) were quantified in the fish muscle tissues to improve the understanding of pollution status and factors regulating the transport and fate of these contaminants on the Plateau. The results showed that lake-averaged ∑(14)PBDEs concentration was between 0.09 ng g(-1) dw and 4.32 ng g(-1) dw, which was lower than those reported for European mountains. The total mercury concentration in individual fish ranged from 243 to 2384 ng g(-1) dw, and that of MeHg from 131 to 1,610 ng g(-1) dw, which is much higher than those reported in other mountain fish. The spatial variation of PBDEs and mercury in the Plateau is largely controlled by the specific meteorological patterns. PMID:21429553

  19. Recovery of Bio-Oil from Industrial Food Waste by Liquefied Dimethyl Ether for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Kiyoshi Sakuragi

    2016-02-01

    Full Text Available The development of new energy sources has become particularly important from the perspective of energy security and environmental protection. Therefore, the utilization of waste resources such as industrial food wastes (IFWs in energy production is expected. The central research institute of electric power industry (CRIEPI, Tokyo, Japan has recently developed an energy-saving oil-extraction technique involving the use of liquefied dimethyl ether (DME, which is an environmentally friendly solvent. In this study, three common IFWs (spent coffee grounds, soybean, and rapeseed cakes were evaluated with respect to oil yield for biodiesel fuel (BDF production by the DME extraction method. The coffee grounds were found to contain 16.8% bio-oil, whereas the soybean and rapeseed cakes contained only approximately 0.97% and 2.6% bio-oil, respectively. The recovered oils were qualitatively analysed by gas chromatography-mass spectrometry. The properties of fatty acid methyl esters derived from coffee oil, such as kinematic viscosity, pour point, and higher heating value (HHV, were also determined. Coffee grounds had the highest oil content and could be used as biofuel. In addition, the robust oil extraction capability of DME indicates that it may be a favourable alternative to conventional oil extraction solvents.

  20. Mono- and dialkyl glycerol ether lipids in anaerobic bacteria: biosynthetic insights from the mesophilic sulfate reducer Desulfatibacillum alkenivorans PF2803T.

    Science.gov (United States)

    Grossi, Vincent; Mollex, Damien; Vinçon-Laugier, Arnauld; Hakil, Florence; Pacton, Muriel; Cravo-Laureau, Cristiana

    2015-05-01

    Bacterial glycerol ether lipids (alkylglycerols) have received increasing attention during the last decades, notably due to their potential role in cell resistance or adaptation to adverse environmental conditions. Major uncertainties remain, however, regarding the origin, biosynthesis, and modes of formation of these uncommon bacterial lipids. We report here the preponderance of monoalkyl- and dialkylglycerols (1-O-alkyl-, 2-O-alkyl-, and 1,2-O-dialkylglycerols) among the hydrolyzed lipids of the marine mesophilic sulfate-reducing proteobacterium Desulfatibacillum alkenivorans PF2803T grown on n-alkenes (pentadec-1-ene or hexadec-1-ene) as the sole carbon and energy source. Alkylglycerols account for one-third to two-thirds of the total cellular lipids (alkylglycerols plus acylglycerols), depending on the growth substrate, with dialkylglycerols contributing to one-fifth to two-fifths of the total ether lipids. The carbon chain distribution of the lipids of D. alkenivorans also depends on that of the substrate, but the chain length and methyl-branching patterns of fatty acids and monoalkyl- and dialkylglycerols are systematically congruent, supporting the idea of a biosynthetic link between the three classes of compounds. Vinyl ethers (1-alken-1'-yl-glycerols, known as plasmalogens) are not detected among the lipids of strain PF2803T. Cultures grown on different (per)deuterated n-alkene, n-alkanol, and n-fatty acid substrates further demonstrate that saturated alkylglycerols are not formed via the reduction of hypothetic alken-1'-yl intermediates. Our results support an unprecedented biosynthetic pathway to monoalkyl/monoacyl- and dialkylglycerols in anaerobic bacteria and suggest that n-alkyl compounds present in the environment can serve as the substrates for supplying the building blocks of ether phospholipids of heterotrophic bacteria. PMID:25724965

  1. Synthesis and Coordination Properties of Trifluoromethyl Decorated Derivatives of 2,6-Bis[(diphenylphosphinoyl)methyl]pyridine N-Oxide Ligands with Lanthanide Ions

    Energy Technology Data Exchange (ETDEWEB)

    Pailloux, Sylvie [University of New Mexico, Albuquerque; Shirima, Cornel Edicome [University of New Mexico, Albuquerque; Ray, Alicia D. [University of New Mexico, Albuquerque; Duesler, Eileen N. [University of New Mexico, Albuquerque; Paine, Robert T. [University of New Mexico, Albuquerque; Klaehn, John D. [Idaho National Laboratory (INL); McIlwain, Michael E [Idaho National Laboratory (INL); Hay, Benjamin [ORNL

    2009-01-01

    Phosphinoyl Grignard-based substitutions on 2,6-bis(chloromethyl)pyridine followed by N-oxidation of the intermediate 2,6-bis(phosphinoyl)methyl pyridine compounds with mCPBA give the target trifunctional ligands 2,6-bis[bis-(2-trifluoromethyl-phenyl)-phosphinoylmethyl]-pyridine 1-oxide (2a) and 2,6-bis[bis-(3,5-bis-trifluoromethyl-phenyl)-phosphinoylmethyl]-pyridine 1-oxide (2b) in high yields. The ligands have been spectroscopically characterized, the molecular structures confirmed by single crystal X-ray diffraction methods and the coordination chemistry surveyed with lanthanide nitrates. Single crystal X-ray diffraction analyses are described for the coordination complexes Nd(2a)(NO3)3, Nd(2a)(NO3)3 (CH3CN)0.5, Eu(2a)(NO3)3 and Nd(2b)(NO3)3 (H2O)1.25; in each case the ligand binds in a tridentate mode to the Ln(III) cation. These structures are compared with the structures found for lanthanide coordination complexes of the parent NOPOPO ligand, [Ph2P(O)CH2]2C5H3NO.

  2. Pra Rancangan Pabrik Pembuatan Shampoo Dengan Bahan Baku Sodium Layryl Ether Sulfonat Kapasitas Produksi 8.000 Ton / Tahun

    OpenAIRE

    Herri Putra

    2009-01-01

    Pabrik Shampoo ini direncanakan berproduksi dengan kapasitas 8.000 ton/tahun dengan 340 hari kerja dalam 1 (satu) tahun. Proses yang digunakan melalui 2 tahap yaitu proses pembuatan Lauryl Ether Sulfonat dan proses pembuatan shampoo. Pembuatan Lauryl Ether Sulfonat dilakukan melalui proses pencampuran Lauryl ether dengan oleum 20% di sulfonator (R-101) dengan temperatur proses 46oC sehingga terbentuk senyawa lauryl ether sulfonat. Kemudian lauryl ether sulfonat ini dinetralisasi dengan mengg...

  3. Pra Rancangan Pabrik Pembuatan Shampoo Dengan Bahan Baku Sodium Layryl Ether Sulfonat Kapasitas Produksi 10.000 Ton / Tahun

    OpenAIRE

    Muhammad Dimas Arhadiansyah

    2009-01-01

    Pabrik Shampoo ini direncanakan berproduksi dengan kapasitas 8.000 ton/tahun dengan 340 hari kerja dalam 1 (satu) tahun. Proses yang digunakan melalui 2 tahap yaitu proses pembuatan Lauryl Ether Sulfonat dan proses pembuatan shampoo. Pembuatan Lauryl Ether Sulfonat dilakukan melalui proses pencampuran Lauryl ether dengan oleum 20% di sulfonator (R-101) dengan temperatur proses 46oC sehingga terbentuk senyawa lauryl ether sulfonat. Kemudian lauryl ether sulfonat ini dinetralisasi dengan mengg...

  4. Electrochemical synthesis of niobium methylate

    International Nuclear Information System (INIS)

    The formation of niobium(V) methylate in methanol against the background of lithium chloride is studied. It is found that, in the anodic dissolution of niobium in the diaphragm-free electrolytic tank, formed niobium(V) methylate is partially reduced to the four-valent state at the cathode. In order to suppress the reduction of Nb(V), an electrolytic tank was designed, which enabled one to separate the anolyte from the catholyte using the difference between their densities. Niobium methylate was not found in the anolyte; however, it formed as a result of mixing the anolyte with the catholyte after completion of electrolysis. The current efficiency of niobium methylate of 96-97% was achieved. Possible mechanism of the process is discussed

  5. Dark matter, Mach's ether and the QCD vacuum

    CERN Document Server

    Cohen-Tannoudji, Gilles

    2015-01-01

    Here is proposed the idea of linking the dark matter issue, (considered as a major problem of contemporary research in physics) with two other open theoretical questions, one, almost centenary about the existence of an unavoidable ether in general relativity agreeing with the Mach's principle, and one more recent about the properties of the quantum vacuum of the quantum field theory of strong interactions, QuantumChromodynamics (QCD). According to this idea, on the one hand, dark matter and dark energy that, according to the current standard model of cosmology represent about 95% of the universe content, can be considered as two distinct forms of the Mach's ether, and, on the other hand, dark matter, as a perfect fluid emerging from the QCD vacuum could be modeled as a Bose Einstein condensate.

  6. Intrinsic Kinetics of Dimethyl Ether Synthesis from Syngas

    Institute of Scientific and Technical Information of China (English)

    Zhaoguang Nie; Hongwei Liu; Dianhua Liu; Weiyong Ying; Dingye Fang

    2005-01-01

    The intrinsic kinetics of dimethyl ether (DME) synthesis from syngas over a methanol synthesis catalyst mixed with methanol dehydration catalyst has been investigated in a tubular integral reactor at 3-7 MPa and 220-260 ℃. The three reactions including methanol synthesis from CO and H2, CO2 and H2, and methanol dehydration were chosen as the independent reactions. The L-H kinetic model was presented for dimethyl ether synthesis and the parameters of the model were obtained by using simplex method combined with genetic algorithm. The model is reliable according to statistical analysis and residual error analysis. The synergy effect of the reactions over the bifunctional catalyst was compared with the effect for methanol synthesis catalyst under the same conditions based on the model. The effects of syngas containing N2 on the reactions were also simulated.

  7. SYNTHESIS OF ALLYL PHENYL ETHER AND CLAISEN REARRANGEMENT

    Directory of Open Access Journals (Sweden)

    Gagik Torosyan

    2011-12-01

    Full Text Available It has been established the possibility for phenol allylation on natural zeolites and them analogs. Here is demonstrated the synthesis of allyl phenol, which has wide industrial applications. The offered method in comparison with the traditional methods has more advantages – higher selectivity, smaller material and power resources consumption. It has been obtained the mixture of allylating phenols (30% in general with allyl phenyl ether (1 with 80% yields. At 600 K is obtained allylphenyl ether, at 700 K beginning the formation of allyl phenols, which is the result of direct C-allylation of the aromatic ring. It has been investigated the possibility of Claisen rearrangement in the same conditions. All of that are established by gas-liquid chromatography and liquid chromatography data.

  8. 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.

  9. HISTONE METHYLATION REGULATES MEMORY FORMATION

    OpenAIRE

    Gupta, Swati; Kim, Se Y.; Artis, Sonja; Molfese, David L.; Schumacher, Armin; Sweatt, J. David; Paylor, Richard E.; Lubin, Farah D.

    2010-01-01

    It has been established that regulation of chromatin structure through post-translational modification of histone proteins, primarily histone H3 phosphorylation and acetylation, is an important early step in the induction of synaptic plasticity and formation of long-term memory. In this study, we investigated the contribution of another histone modification, histone methylation, to memory formation in the adult hippocampus. We found that tri-methylation of histone H3 at lysine 4 (H3K4), an ac...

  10. Methylation: a regulator of HIV-1 replication?

    OpenAIRE

    Jeang Kuan-Teh; Yedavalli Venkat RK

    2007-01-01

    Abstract Recent characterizations of methyl transferases as regulators of cellular processes have spurred investigations into how methylation events might influence the HIV-1 life cycle. Emerging evidence suggests that protein-methylation can positively and negatively regulate HIV-1 replication. How DNA- and RNA- methylation might impact HIV-1 is also discussed.

  11. Synthesis and adsorption properties of chitosan-crown ether resins

    Institute of Scientific and Technical Information of China (English)

    彭长宏; 陈艺锋; 唐谟堂

    2003-01-01

    Two kinds of novel chitosan-crown ether resins, Schiff base type chitosan-benzo-15-crown-5 (CTS-B15)and chitosan-benzo-18-crown-6 (CTS-B18), were synthesized through the reaction between -NH2 in chitosan and -CHO in 4′-formyl benzo-crown ethers. Their structures were characterized by elemental analysis and FT-IR spectra analysis. The elemental analysis results show that the mass fractions of nitrogen in CTS-B15 and CTS-B18 are much lower than those of chitosan. The results of FT-IR spectra of CTS-B15 and CTS-B18 reveal that there exist characteristic peak of C= N, N-H and Ar, and characteristic peak of pyr anoside in the chain of chitosan-crown ether resins, showing that the structures of chitosan-crown ethers are as expected. The adsorption properties of CTS-B15 and CTS-B18 for Pd2+ , Cu2 + and Hg2+ were studied and the experimental results show that these adsorbents have both good adsorption characterization and especially high particular adsorption selectivity for Pd2+ when Cu2+ and Hg2+ are in coexistence, and the coefficients of selectivity of CTS-B15 and CTS-B18 for metal ions are KPd2+/cu2+ =7.56, KPd2+/Hg2+ = 68.00, Kcu2+/Hg2+ = 9.00 and KPd2+/cu2+ = 6.00, KPd2+/Hg2+ = 19. 00, Kcu2+/Hg2+ = 3.00, respectively.

  12. Photodissociation of Non-Covalent Peptide-Crown Ether Complexes

    OpenAIRE

    Wilson, Jeffrey J.; Kirkovits, Gregory J.; Sessler, Jonathan L.; Brodbelt, Jennifer S.

    2007-01-01

    Highly chromogenic 18-crown-6-dipyrrolylquinoxaline coordinates primary amines of peptides, forming non-covalent complexes that can be transferred to the gas phase by electrospray ionization. The appended chromogenic crown ether facilitates efficient energy transfer to the peptide upon ultraviolet irradiation in the gas phase, resulting in diagnostic peptide fragmentation. Collisional activated dissociation (CAD) and infrared multiphoton dissociation (IRMPD) of these non-covalent complexes re...

  13. Detonation characteristics of dimethyl ether and ethanol-air mixtures

    Science.gov (United States)

    Diakow, P.; Cross, M.; Ciccarelli, G.

    2015-05-01

    The detonation cell structure in dimethyl ether vapor and ethanol vapor-air mixtures was measured at atmospheric pressure and initial temperatures in the range of 293-373 K. Tests were carried out in a 6.2-m-long, 10-cm inner diameter tube. For more reactive mixtures, a series of orifice plates were used to promote deflagration-to-detonation transition in the first half of the tube. For less reactive mixtures prompt detonation initiation was achieved with an acetylene-oxygen driver. The soot foil technique was used to capture the detonation cell structure. The measured cell size was compared to the calculated one-dimensional detonation reaction zone length. For fuel-rich dimethyl ether mixtures the calculated reaction zone is highlighted by a temperature gradient profile with two maxima, i.e., double heat release. The detonation cell structure was interpreted as having two characteristic sizes over the full range of mixture compositions. For mixtures at the detonation propagation limits the large cellular structure approached a single-head spin, and the smaller cells approached the size of the tube diameter. There is little evidence to support the idea that the two cell sizes observed on the foils are related to the double heat release predicted for the rich mixtures. There was very little influence of initial temperature on the cell size over the temperature range investigated. A double heat release zone was not predicted for ethanol-air detonations. The detonation cell size for stoichiometric ethanol-air was found to be similar to the size of the small cells for dimethyl ether. The measured cell size for ethanol-air did not vary much with composition in the range of 30-40 mm. For mixtures near stoichiometric it was difficult to discern multiple cell sizes. However, near the detonation limits there was strong evidence of a larger cell structure similar to that observed in dimethyl ether air mixtures.

  14. The epistemic view of quantum states and the ether

    CERN Document Server

    Marchildon, L

    2005-01-01

    The idea that the wave function represents information, or knowledge, rather than the state of a microscopic object has been held to solve foundational problems of quantum mechanics. Realist interpretation schemes, like Bohmian trajectories, have been compared to the ether in pre-relativistic theories. I argue that the comparison is inadequate, and that the epistemic view of quantum states begs the question of interpretation.

  15. Synthesis of active nitroguaiacol ether derivatives of streptomycin.

    OpenAIRE

    Abad, J P; Amils, R.

    1990-01-01

    The synthesis, purification, and biological properties of nitroguaiacol ether derivatives of streptomycin and their corresponding radioactive reduced products were examined. These derivatives are biologically active against gram-positive and gram-negative eubacteria and they are also photoreactive because of the presence of the nitroguaiacol group in the molecule. We demonstrated that these derivatives can be used as streptomycin analogs in photoaffinity labeling of the macromolecular structu...

  16. Glycerol ether lipids in sediments: sources, diversity and implications

    OpenAIRE

    Liu, Xiao-Lei

    2011-01-01

    Glycerol ether lipids are prominent membrane constituents in Archaea and Bacteria that are characterized by high potential for preservation in geological settings.During the past decade they were increasingly used in molecular proxies. For example,selected glycerol dialkyl glycerol tetraethers (GDGT) are used in ratios such as the TEX86 and BIT index for reconstructing past sea surface temperature (SST) and terrestrial input, respectively. However, the distribution and structural diversity of...

  17. Study on Synergy Effect in Dimethyl Ether Synthesis from Syngas

    Institute of Scientific and Technical Information of China (English)

    王志良; 刁杰; 王金福; 金涌

    2001-01-01

    Influence of reaction temperature, pressure and space velocity on the direct synthesis of dimethyl ether (DME) from syngas is studied in an isothermal fixed-bed reactor. The catalyst is a physical mixture of C30 copper-based methanol (MeOH) synthesis catalyst and ZSM-5 dehydration catalyst. The experimental results show that the chemical synergy between methanol synthesis reaction and methanol dehydration reaction is evident. The conversion of carbon monoxide is over 90%.

  18. Gravitation as a pressure force: a scalar ether theory

    OpenAIRE

    Arminjon, Mayeul

    2011-01-01

    If the presence of a gravitational field breaks the Lorentz symmetry valid for special relativity, an "absolute motion" might be detectable. We summarize a scalar theory of gravity with a such "ether", which starts from a tentative interpretation of gravity as a pressure force. The theory also admits that our physical standards of space and time are affected by gravitation similarly as they are affected by a uniform motion. General motion is governed by an extension of Newton's second law to ...

  19. A constitutive model of polyether-ether-ketone (PEEK).

    Science.gov (United States)

    Chen, Fei; Ou, Hengan; Lu, Bin; Long, Hui

    2016-01-01

    A modified Johnson-Cook (JC) model was proposed to describe the flow behaviour of polyether-ether-ketone (PEEK) with the consideration of coupled effects of strain, strain rate and temperature. As compared to traditional JC model, the modified one has better ability to predict the flow behaviour at elevated temperature conditions. In particular, the yield stress was found to be inversely proportional to temperature from the predictions of the proposed model. PMID:26409233

  20. Determination of polybrominated diphenyl ethers in environmental standard reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Stapleton, Heather M.; Schantz, Michele M.; Wise, Stephen A. [National Institute of Standards and Technology, Analytical Chemistry Division, Gaithersburg, MD (United States); Keller, Jennifer M.; Kucklick, John R. [National Institute of Standards and Technology, Analytical Chemistry Division, Hollings Marine Laboratory, Charleston, SC (United States); Leigh, Stefan D. [National Institute of Standards and Technology, Statistical Engineering Division, Gaithersburg, MD (United States)

    2007-04-15

    Standard reference materials (SRMs) are valuable tools in developing and validating analytical methods to improve quality assurance standards. The National Institute of Standards and Technology (NIST) has a long history of providing environmental SRMs with certified concentrations of organic and inorganic contaminants. Here we report on new certified and reference concentrations for 27 polybrominated diphenyl ether (PBDE) congeners in seven different SRMs: cod-liver oil, whale blubber, fish tissue (two materials), mussel tissue and sediment (two materials). PBDEs were measured in these SRMs, with the lowest concentrations measured in mussel tissue (SRM 1974b) and the highest in sediment collected from the New York/New Jersey Waterway (SRM 1944). Comparing the relative PBDE congener concentrations within the samples, we found the biota SRMs contained primarily tetrabrominated and pentabrominated diphenyl ethers, whereas the sediment SRMs contained primarily decabromodiphenyl ether (BDE 209). The cod-liver oil (SRM 1588b) and whale blubber (SRM 1945) materials were also found to contain measurable concentrations of two methoxylated PBDEs (MeO-BDEs). Certified and reference concentrations are reported for 12 PBDE congeners measured in the biota SRMs and reference values are available for two MeO-BDEs. Results from a sediment interlaboratory comparison PBDE exercise are available for the two sediment SRMs (1941b and 1944). (orig.)

  1. Sulfonated Poly(Ether Ether Ketone)/Functionalized Carbon Nanotube Composite Membrane for Vanadium Redox Flow Battery Applications

    International Nuclear Information System (INIS)

    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

  2. Influence of the angle between two crown ether moieties on supramolecular copolymerization of bis(crown ether)s and bisparaquat homoditopic monomers

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Bis(crown ether) homoditopic monomers containing two bis(p-phenylene)-34-crown-10 moieties with different angles(180° for monomer 3,120°for monomer 4,and 60°for monomer 5) and a complementary bisparaquat homoditopic monomer(7) were designed and synthesized.The three bis(crown ether) monomers could organize into linear supramolecular polymers in concentrated solutions in CHCl3/CH3CN with the bisparaquat monomer 7,as demonstrated by 1 H NMR and viscosity studies. The pseudorotaxanes or supramolecular polymers formed from 3+7 and 4+7 had larger values of Ka,p,n,slope 1,and slope 2 than those of 5+7.This result was attributed to the greater steric hindrance of compound 5 than that of 3 and 4,which resulted in less effective formation of linear supramolecular polymers from 5 with compound 7 than those from compounds 3 and 4 with compound 7,as also demonstrated by UV-vis method.

  3. Biosorption and degradation of decabromodiphenyl ether by Brevibacillus brevis and the influence of decabromodiphenyl ether on cellular metabolic responses.

    Science.gov (United States)

    Wang, Linlin; Tang, Litao; Wang, Ran; Wang, Xiaoya; Ye, Jinshao; Long, Yan

    2016-03-01

    There is global concern about the effects of decabromodiphenyl ether (BDE209) on environmental and public health. The molecular properties, biosorption, degradation, accumulation, and cellular metabolic effects of BDE209 were investigated in this study to identify the mechanisms involved in the aerobic biodegradation of BDE209. BDE209 is initially absorbed by wall teichoic acid and N-acetylglucosamine side chains in peptidoglycan, and then, BDE209 is transported and debrominated through three pathways, giving tri-, hepta-, octa-, and nona-bromodiphenyl ethers. The C-C bond energies decrease as the number of bromine atoms on the diphenyl decreases. Polybrominated diphenyl ethers (PBDEs) inhibit protein expression or accelerate protein degradation and increase membrane permeability and the release of Cl(-), Na(+), NH4 (+), arabinose, proteins, acetic acid, and oxalic acid. However, PBDEs increase the amounts of K(+), Mg(2+), PO4 (3-), SO4 (2-), and NO3 (-) assimilated. The biosorption, degradation, accumulation, and removal efficiencies when Brevibacillus brevis (1 g L(-1)) was exposed to BDE209 (0.5 mg L(-1)) for 7 days were 7.4, 69.5, 16.3, and 94.6 %, respectively. PMID:26555880

  4. Size-exclusion chromatography of ultrahigh molecular weight methylcellulose ethers and hydroxypropyl methylcellulose ethers for reliable molecular weight distribution characterization.

    Science.gov (United States)

    Li, Yongfu; Shen, Hongwei; Lyons, John W; Sammler, Robert L; Brackhagen, Meinolf; Meunier, David M

    2016-03-15

    Size-exclusion chromatography (SEC) coupled with multi-angle laser light scattering (MALLS) and differential refractive index (DRI) detectors was employed for determination of the molecular weight distributions (MWD) of methylcellulose ethers (MC) and hydroxypropyl methylcellulose ethers (HPMC) having weight-average molecular weights (Mw) ranging from 20 to more than 1,000kg/mol. In comparison to previous work involving right-angle light scattering (RALS) and a viscometer for MWD characterization of MC and HPMC, MALLS yields more reliable molecular weight for materials having weight-average molecular weights (Mw) exceeding about 300kg/mol. A non-ideal SEC separation was observed for cellulose ethers with Mw>800kg/mol, and was manifested by upward divergence of logM vs. elution volume (EV) at larger elution volume at typical SEC flow rate such as 1.0mL/min. As such, the number-average molecular weight (Mn) determined for the sample was erroneously large and polydispersity (Mw/Mn) was erroneously small. This non-ideality resulting in the late elution of high molecular weight chains could be due to the elongation of polymer chains when experimental conditions yield Deborah numbers (De) exceeding 0.5. Non-idealities were eliminated when sufficiently low flow rates were used. Thus, using carefully selected experimental conditions, SEC coupled with MALLS and DRI can provide reliable MWD characterization of MC and HPMC covering the entire ranges of compositions and molecular weights of commercial interest. PMID:26794765

  5. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Science.gov (United States)

    2010-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene......

  6. Safety Assessment of Alkyl PEG/PPG Ethers as Used in Cosmetics.

    Science.gov (United States)

    Fiume, Monice M; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2016-07-01

    The Cosmetic Ingredient Review (CIR) Expert Panel assessed the safety of 131 alkyl polyethylene glycol (PEG)/polypropylene glycol ethers as used in cosmetics, concluding that these ingredients are safe in the present practices of use and concentration described in this safety assessment when formulated to be nonirritating. Most of the alkyl PEG/PPG ethers included in this review are reported to function in cosmetics as surfactants, skin-conditioning agents, and/or emulsifying agents. The alkyl PEG/PPG ethers share very similar physiochemical properties as the alkyl PEG ethers, which were reviewed previously by the CIR Expert Panel and found safe when formulated to be nonirritating. The alkyl PEG ethers differ by the inclusion of PPG repeat units, which are used to fine-tune the surfactant properties of this group. The Panel relied heavily on data on analogous ingredients, extracted from the alkyl PEG ethers and PPG reports, when making its determination of safety. PMID:27383199

  7. Carcinogen-induced DNA repair in nucleotide-permeable Escherichia coli cells. Induction of DNA repair by the carcinogens methyl and ethyl nitrosourea and methyl methanesulfonate.

    Science.gov (United States)

    Thielmann, H W; Vosberg, H P; Reygers, U

    1975-08-15

    Ether-permeabilized (nucleotide-permeable) cells of Escherichia coli show excision repair of their DNA after having been exposed to the carcinogens N-methyl-N-nitrosourea (MeNOUr), N-ethyl-N-nitrosourea (EtNOUr) and methyl methanesulfonate (MeSO2OMe) which are known to bind covalently to DNA. Defect mutations in genes uvrA, uvrB, uvrC, recA, recB, recC and rep did not inhibit this excision repair. Enzymic activities involved in this repair were identified by measuring size reduction of DNA, DNA degradation to acid-soluble nucleotides and repair polymerization. 1. In permeabilized cells methyl and ethyl nitrosourea induced endonucleolytic cleavage of endogenous DNA, as determined by size reduction of denatured DNA in neutral and alkaline sucrose gradients. An enzymic activity from E. coli K-12 cell extracts was purified (greater than 2000-fold) and was found to cleave preferentially methyl-nitrosourea-treated DNA and to convert the methylated supercoiled DNA duplex (RFI) of phage phiX 174 into the nicked circular form. 2. Degradation of alkylated cellular DNA to acid solubility was diminished in a mutant lacking the 5' leads to 3' exonucleolytic activity of DNA polymerase I but was not affected in a mutant which lacked the DNA polymerizing but retained the 5' leads 3' exonucleolytic activity of DNA polymerase I. 3. An easily measurable effect is carcinogen-induced repair polymerization, making it suitable for detection of covalent binding of carcinogens and potentially carcinogenic compounds. PMID:170107

  8. Mechanisms of flash pyrolysis of ether lipids isolated from the green microalga Botryococcus braunii race

    OpenAIRE

    Sinninghe Damsté, J.S.; Gelin, F.; Gatellier, J-P.L.A.; Metzger, P.; Derenne, S.; Largeau, C.; Leeuw, J.W. de

    1993-01-01

    Two types of ether lipids isolated from the microalga Botryococcus braunii have been subjected to flash pyrolysis. The pyrolysis products were separated and analyzed by GC/MS. The nature and distribution of the pyrolysis compounds gave clues to the different mechanisms involved in the pyrolysis of ether-linked alkyl chains. The relatively abundant presence of alkenes, alkadienes, alken-9-ones and alken-10-ones with chain lengths corresponding to those of the ether-bound alkyl chains indicated...

  9. PCMdb: Pancreatic Cancer Methylation Database

    Science.gov (United States)

    Nagpal, Gandharva; Sharma, Minakshi; Kumar, Shailesh; Chaudhary, Kumardeep; Gupta, Sudheer; Gautam, Ankur; Raghava, Gajendra P. S.

    2014-02-01

    Pancreatic cancer is the fifth most aggressive malignancy and urgently requires new biomarkers to facilitate early detection. For providing impetus to the biomarker discovery, we have developed Pancreatic Cancer Methylation Database (PCMDB, http://crdd.osdd.net/raghava/pcmdb/), a comprehensive resource dedicated to methylation of genes in pancreatic cancer. Data was collected and compiled manually from published literature. PCMdb has 65907 entries for methylation status of 4342 unique genes. In PCMdb, data was compiled for both cancer cell lines (53565 entries for 88 cell lines) and cancer tissues (12342 entries for 3078 tissue samples). Among these entries, 47.22% entries reported a high level of methylation for the corresponding genes while 10.87% entries reported low level of methylation. PCMdb covers five major subtypes of pancreatic cancer; however, most of the entries were compiled for adenocarcinomas (88.38%) and mucinous neoplasms (5.76%). A user-friendly interface has been developed for data browsing, searching and analysis. We anticipate that PCMdb will be helpful for pancreatic cancer biomarker discovery.

  10. 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.

  11. Activity of organophosphorus insecticides in bacterial tests for mutagenicity and DNA repair--direct alkylation versus metabolic activation and breakdown. II. O,O-dimethyl-O-(1,2-dibromo-2,2-dichloroethyl)-phosphate and two O-ether derivatives of trichlorfon.

    Science.gov (United States)

    Braun, R; Schöneich, J; Weissflog, L; Dedek, W

    1983-03-01

    The following organophosphates were tested for their ability to induce DNA damage in a rec-type repair test with Proteus mirabilis strains PG713 (rec- hcr-) and PG273 (wild-type) and point mutations in the his- strain TA100 of Salmonella typhimurium: O,O-dimethyl-O-(1,2-dibromo-2,2-dichloroethyl)-phosphate (NALED); trichlorfon-O-methyl ether (TCP-O-ME), O,O-dimethyl-(1-methoxy-2,2,2-trichlorethyl)-phosphonate; trichlorfon-O-methyl ether vinyl derivative (TCP-O-MEVD), O,O-dimethyl-(1-methoxy-2,2-dichlorovinyl)-phosphonate. All compounds were negative in the repair test but induced base pair substitutions in S. typhimurium. The mutagenicity of NALED is due to the direct alkylating ability of the parental molecule and to mutagenic metabolites generated by enzymatic splitting of the side chain. Glutathion-dependent enzymes in the S9-mix eliminate the mutagenic activity of NALED completely. Mutation induction by TCP-O-ME and TCP-O-MEVD is predominantly caused by the reactive O-methyl ether configuration of the side chain and is resistant to metabolic inactivation by NADPH- or glutathion-dependent enzymatic pathways in the S9-mix of mice. PMID:6337735

  12. Microbial degradation of 4-monobrominated diphenyl ether with anaerobic sludge

    International Nuclear Information System (INIS)

    Highlights: ► BDE-3 was degraded with two anaerobes in different rates. ► Glucose addition augment the debromination efficiencies. ► Hydrogen gas was detected and relative microbes were identified. ► Extra-carbon source enhanced degradation partial due to H2-generation bacteria. - Abstract: Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant additives for many plastic and electronic products. Owing to their ubiquitous distribution in the environment, multiple toxicity to humans, and increasing accumulation in the environment, the fate of PBDEs is of serious concern for public safety. In this study, the degradation of 4-monobrominated diphenyl ether (BDE-3) in anaerobic sludge and the effect of carbon source addition were investigated. BDE-3 can be degraded by two different anaerobic sludge samples. The by-products, diphenyl ether (DE) and bromide ions, were monitored, indicating the reaction of debromination within these anaerobic samples. Co-metabolism with glucose facilitated BDE-3 biodegradation in terms of kinetics and efficiency in the Jhongsing sludge. Through the pattern of amplified 16S rRNA gene fragments in denatured gradient gel electrophoresis (DGGE), the composition of the microbial community was analyzed. Most of the predominant microbes were novel species. The fragments enriched in BDE-3-degrading anaerobic sludge samples are presumably Clostridium sp. This enrichment coincides with the H2 gas generation and the facilitation of debromination during the degradation process. Findings of this study provide better understanding of the biodegradation of brominated DEs and can facilitate the prediction of the fate of PBDEs in the environment.

  13. On the radiation stability of crown ethers in ionic liquids.

    Energy Technology Data Exchange (ETDEWEB)

    Shkrob, I.; Marin, T.; Dietz, M. (Chemical Sciences and Engineering Division); (Benedictine Univ.); (Univ. of Wisconsin at Milwaukee)

    2011-04-14

    Crown ethers (CEs) are macrocyclic ionophores used for the separation of strontium-90 from acidic nuclear waste streams. Room temperature ionic liquids (ILs) are presently being considered as replacements for traditional molecular solvents employed in such separations. It is desirable that the extraction efficacy obtained with such solvents should not deteriorate in the strong radiation fields generated by decaying radionuclides. This deterioration will depend on the extent of radiation damage to both the IL solvent and the CE solute. While radiation damage to ILs has been extensively studied, the issue of the radiation stability of crown ethers, particularly in an IL matrix, has not been adequately addressed. With this in mind, we have employed electron paramagnetic resonance (EPR) spectroscopy to study the formation of CE-related radicals in the radiolysis of selected CEs in ILs incorporating aromatic (imidazolium and pyridinium) cations. The crown ethers have been found to yield primarily hydrogen loss radicals, H atoms, and the formyl radical. In the low-dose regime, the relative yield of these radicals increases linearly with the mole fraction of the solute, suggesting negligible transfer of the excitation energy from the solvent to the solute; that is, the solvent has a 'radioprotective' effect. The damage to the CE in the loading region of practical interest is relatively low. Under such conditions, the main chemical pathway leading to decreased extraction performance is protonation of the macrocycle. At high radiation doses, sufficient to increase the acidity of the IL solvent significantly, such proton complexes compete with the solvent cations as electron traps. In this regime, the CEs will rapidly degrade as the result of H abstraction from the CE ring by the released H atoms. Thus, the radiation dose to which a CE/IL system is exposed must be maintained at a level sufficiently low to avoid this regime.

  14. Equimolar carbon dioxide absorption by ether functionalized imidazolium ionic liquids

    International Nuclear Information System (INIS)

    A series [C3Omim][X] of imidazolium cation-based ILs, with ether functional group on the alkyl side-chain have been synthesized and structure of the materials were confirmed by various techniques like 1H, 13C NMR spectroscopy, MS-ESI, FTIR spectroscopy and EA. More specifically, the influence of changing the anion with same cation is carried out. The absorption capacity of CO2 for ILs were evaluated at 30 and 50 .deg. C at ambient pressure (0-1.6 bar). Ether functionalized ILs shows significantly high absorption capacity for CO2. In general, the CO2 absorption capacity of ILs increased with a rise in pressure and decreased when temperature was raised. The obtained results showed that absorption capacity reached about 0.9 mol CO2 per mol of IL at 30 .deg. C. The most probable mechanism of interaction of CO2 with ILs were investigated using FTIR spectroscopy, 13C NMR spectroscopy and result shows that the absorption of CO2 in ether functionalized ILs is a chemical process. The CO2 absorption results and detailed study indicates the predominance of 1:1 mechanism, where the CO2 reacts with one IL to form a carbamic acid. The CO2 absorption capacity of ILs for different anions follows the trend: BF4 6 2N. Moreover, the as-synthesized ILs is selective, thermally stable, long life operational and can be recycled at a temperature of 70 .deg. C or under vacuum and can be used repeatedly

  15. Subchronic exposure to ethyl tertiary butyl ether resulting in genetic damage in Aldh2 knockout mice.

    Science.gov (United States)

    Weng, Zuquan; Suda, Megumi; Ohtani, Katsumi; Mei, Nan; Kawamoto, Toshihiro; Nakajima, Tamie; Wang, Rui-Sheng

    2013-09-15

    Ethyl tertiary butyl ether (ETBE) is biofuel additive recently used in Japan and some other countries. Limited evidence shows that ETBE has low toxicity. Acetaldehyde (AA), however, as one primary metabolite of ETBE, is clearly genotoxic and has been considered to be a potential carcinogen. The aim of this study was to evaluate the effects of ALDH2 gene on ETBE-induced genotoxicity and metabolism of its metabolites after inhalation exposure to ETBE. A group of wild-type (WT) and Aldh2 knockout (KO) C57BL/6 mice were exposed to 500ppm ETBE for 1-6h, and the blood concentrations of ETBE metabolites, including AA, tert-butyl alcohol and 2-methyl-1,2-propanediol, were measured. Another group of mice of WT and KO were exposed to 0, 500, 1750, or 5000ppm ETBE for 6h/day with 5 days per weeks for 13 weeks. Genotoxic effects of ETBE in these mice were measured by the alkaline comet assay, 8-hydroxyguanine DNA-glycosylase modified comet assay and micronucleus test. With short-term exposure to ETBE, the blood concentrations of all the three metabolites in KO mice were significantly higher than the corresponding concentrations of those in WT mice of both sexes. After subchronic exposure to ETBE, there was significant increase in DNA damage in a dose-dependent manner in KO male mice, while only 5000ppm exposure significantly increased DNA damage in male WT mice. Overall, there was a significant sex difference in genetic damage in both genetic types of mice. These results showed that ALDH2 is involved in the detoxification of ETBE and lack of enzyme activity may greatly increase the sensitivity to the genotoxic effects of ETBE, and male mice were more sensitive than females. PMID:23810710

  16. Performance and emission characteristics of QHCCI dimethyl ether engine

    Institute of Scientific and Technical Information of China (English)

    Ying WANG; Wei LI; Tiegang HU; Longbao ZHOU; Shenghua LIU

    2008-01-01

    Experimental investigation into the effects of different pilot amounts of dimethyl ether (DME) on the performance and emission of a single-cylinder direct-injection DME engine is conducted. The results show that a DME engine can operate at a wider range of speeds and loads at quasi-homogenous charge compression ignition (QHCCI) mode. The brake thermal efficiency increases while the exhaust temperature decreases. NOx emission decreases by about 30%-50% although there is a slight increase in HC and CO emissions. NOx, HC and CO emissions increase with an increase in the amount of DME pilot. QHCCI is a good way to increase thermal efficiency and decrease NOx emission.

  17. Direct dimethyl ether high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Vassiliev, Anton; Jensen, Jens Oluf; Li, Qingfeng;

    A high temperature polybenzimidazole (PBI) polymer fuel cell was fed with dimethyl ether (DME) and water vapour mixture on the anode at ambient pressure with air as oxidant. A peak power density of 79 mW/cm2 was achieved at 200°C. A conventional polymer based direct DME fuel cell is liquid fed and...... suffers from low DME solubility in water. When the DME - water mixture is fed as vapour miscibility is no longer a problem. The increased temperature is more beneficial for the kinetics of the direct oxidation of DME than of methanol. The Open Circuit Voltage (OCV) with DME operation was 50 to 100 m...

  18. Dimethyl ether in diesel engines - progress and perspectives

    DEFF Research Database (Denmark)

    Sorenson, Spencer C

    2001-01-01

    aspects are discussed A simplified theoretical explanation of the emissions behavior of DME is presented A discussion is presented proposing DME as a significant factor in the future international energy picture. Dire to its beneficial combustion properties, possibility of production from a variety of......A review of recent developments related to the use of dimethyl ether (DME) in engines is presented Research work discussed is in the areas of engine performance and emissions, fuel injection systems, spray and ignition delay, and detailed chemical kinetic modeling. DME's properties and safety...

  19. Catalytic Dealkylation of Ethers to Alcohols on Metal Surfaces.

    Science.gov (United States)

    Yang, Biao; Lin, Haiping; Miao, Kangjian; Zhu, Pan; Liang, Liangbo; Sun, Kewei; Zhang, Haiming; Fan, Jian; Meunier, Vincent; Li, Youyong; Li, Qing; Chi, Lifeng

    2016-08-16

    On-surface synthesis has prompted much interest in recent years because it provides an alternative strategy for controlling chemical reactions and allows for the direct observation of reaction pathways. Herein, we combined scanning tunneling microscopy and density functional theory to provide extensive evidence for the conversion of alkoxybenzene-containing ethers into alcohols by means of surface synthesis. The reported dealkylation reactions are finely controlled by the annealing parameters, which govern the onset of successive alkyl chains dissociations. Moreover, density functional theory calculations elucidate the details of the reaction pathways, showing that dealkylation reactions are surface-assisted and very different from their homogeneous analogues in solution. PMID:27432690

  20. Photochemical Degradation of Polybrominated Diphenyl Ethers in Microreactor

    Czech Academy of Sciences Publication Activity Database

    Vajglová, Zuzana; Veselý, M.; Hejda, S.; Vondráčková, Magdalena; Křišťál, Jiří; Cajthaml, Tomáš; Křesinová, Zdena; Tříska, Jan; Klusoň, Petr; Jiřičný, Vladimír

    2015-01-01

    Roč. 41, č. 12 (2015), s. 9373-9381. ISSN 0922-6168. [Pannonian Symposium on Catalysis /12./. Castle Trest, 16.09.2014-20.09.2014] R&D Projects: GA ČR(CZ) GAP105/12/0664; GA ČR GA104/09/0880 Institutional support: RVO:67985858 ; RVO:61388971 ; RVO:67179843 Keywords : polybrominated diphenyl ethers * photochemical microreactor * debromination * photo degradation Subject RIV: CI - Industrial Chemistry, Chemical Engineering; EH - Ecology, Behaviour (UEK-B) Impact factor: 1.221, year: 2014

  1. Isotope effects of zinc in crown ether chromatography

    International Nuclear Information System (INIS)

    Isotope separation of zinc has been studied with a polymer-supported crown ether resin packed in glass columns. Chromatography was performed in a break-through manner by feeding a zinc chloride solution into the columns. The mass analysis revealed that the heavier isotope was enriched at the front part of the zinc adsorption band. This result means that the heavier isotopes are preferentially fractionated into the solution phase. The largest single-stage separation coefficient (ε) in the present work is 1.0 x 10-3 for the isotopic pair of 64Zn and 66Zn at 35degC. (author)

  2. Hydrogen bonding in the recovery of phenols and methyl-t-butyl ether : molecular modeling and calorimetry

    NARCIS (Netherlands)

    Cuypers, R.

    2010-01-01

    The purification of waste water is very important, for clean potable water is a common good and a necessity. Surface water purification is nowadays carried out on a massive industrial scale, and clean water is at our disposal virtually everywhere and always. However, cleaning industrial waste water

  3. Environmental potential of the alternative automotive fuels biogas, ethanol, methanol, natural gas, rape oil methyl ester, and dimethyl ether

    International Nuclear Information System (INIS)

    The aim of the project was to estimate the future emission levels when using alternative fuels, as a contribution to the Committee for Evaluation of Alternative Automotive Fuels (organized by the Swedish Ministry of Environment). The method used for the project was to use the today's knowledge about the emission levels and the emission control technology as a base for the estimation of what additional potential there is to decrease the emissions by coming development of vehicles and the emission control technology. The results of the analysis and the estimations show that there exist a positive development for all types of vehicles and alternative fuels. However, there will be a difference between the different fuel alternatives depending on chemical and physical differences between the different fuels. There will also be a difference in the possibilities of the different fuels to capture a market which will have certain impact on the willingness and the economic possibilities for the car manufacturers to invest in the development needed to reach low emission levels. 124 refs

  4. Preparation and characterization of Pd doped ceria–ZnO nanocomposite catalyst for methyl tert-butyl ether (MTBE) photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Seddigi, Zaki S. [Chemistry Department, Umm Al-Qura University, Makkah (Saudi Arabia); Bumajdad, Ali [Chemistry Department, Faculty of Science, Kuwait University (Kuwait); Ansari, Shahid P. [Chemistry Department, Umm Al-Qura University, Makkah (Saudi Arabia); Ahmed, Saleh A., E-mail: saleh_63@hotmail.com [Chemistry Department, Umm Al-Qura University, Makkah (Saudi Arabia); Danish, Ekram Y. [Chemistry Department, King Abdulaziz University, Jeddah (Saudi Arabia); Yarkandi, Naeema H. [Chemistry Department, Umm Al-Qura University, Makkah (Saudi Arabia); Ahmed, Shakeel [Center for Refining and Petrochemicals, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2014-01-15

    Highlights: • Novel Pd supported ceria–ZnO photocatalysts were prepared with different amounts of palladium. • The photocatalytic activity of these catalysts was evaluated for degradation of MTBE in water. • Near complete removal of MTBE was achieved using 1% Pd doped ceria–ZnO catalyst and UV irradiation. • Highest rate constant was obtained in case of 1% Pd doped ceria–ZnO catalyst. • Shape and size of pores are important factors for high photoactivity of catalyst. -- Abstract: A series of binary oxide catalysts (ceria–ZnO) were prepared and doped with different amounts of palladium in the range of 0.5%–1.5%. The prepared catalysts were characterized by SEM, TEM, XRD and XPS, as well as by N{sub 2} sorptiometry study. The XPS results confirmed the structure of the Pd CeO{sub 2−x}-ZnO. The photocatalytic activity of these catalysts was evaluated for degradation of MTBE in water. These photocatalyst efficiently degrade a 100 ppm aqueous solution of MTBE upon UV irradiation for 5 h in the presence of 100 mg of each of these photocatalysts. The removal of 99.6% of the MTBE was achieved with the ceria–ZnO catalyst doped with 1% Pd. In addition to the Pd loading, the N{sub 2} sorptiometry study introduced other factors that might affect the catalytic efficiency is the catalyst average pore sizes. The photoreaction was determined to be a first order reaction.

  5. AN EXPERIMENTAL STUDY OF PHYTOREMEDIATION OF METHYL-TERT-BUTYL-ETHER (MTBE) IN GROUNDWATER. (R825549C062)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  6. ADVANCED OXIDATION PROCESSES (AOPS) FOR DESTRUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE -AN UNREGULATED CONTAMINANT) IN DRINKING WATER

    Science.gov (United States)

    Advanced oxidation processes (AOPs) provide a promising treatment option for the destruction of MTBE directly in surface and ground waters. An ongoing study is evaluating the ability of three AOPs; hydrogen peroxide/ozone (H2O2/ O3), ultraviolet irradiation/ozone (UV/O3) and ultr...

  7. Novel architecture design of ultra low-fouling block copolymers of oligo ethylene glycol methyl ether methacrylate and carboxybetaine acrylamide

    Czech Academy of Sciences Publication Activity Database

    Rodriguez-Emmenegger, Cesar; Hasan, B.; Brynda, Eduard; Houska, Milan; Sedláková, Zdeňka; Bologna Alles, A.; Gautrot, J.; Huck, W.

    Praha : Ústav makromolekulární chemie AV ČR, 2009. L5. ISBN 978-80-85009-60-6. [Workshop: Career in Polymers. 10.07.2009-11.07.2009, Prague] R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z40500505 Subject RIV: CD - Macromolecular Chemistry

  8. Thin film composite nanofiltration membranes fabricated from quaternized poly(ether ether ketone) with crosslinkable moiety using a benign solvent.

    Science.gov (United States)

    Dong, Xue; Zhang, Qifeng; Zhang, Suobo; Li, Shenghai

    2016-02-01

    Thin film composite nanofiltration membranes were fabricated through dip-coating and in situ cross-linking of quaternized poly(ether ether ketone) containing a certain amount of tertiary amine groups (QAPEEKs) on polyacrylonitrile (PAN) support. The effects of the variables in membrane formation such as the coating polymer concentration, the curing temperature, and the cross-linking agent types on resultant membrane were studied and the membrane properties such as the barrier layer chemical structure, the surface element composition and morphology were investigated. The obtained performance of uncross-linked and cross-linked QAPEEK-70 thin film composites in nanofiltration test was compared. The results indicated that the cross-linking improved the composite membranes' performance. For instance, the membrane cross-linked by bisphenol A diglycidyl ether (BPADGE) named M-C-BPADGE exhibited a MgCl2 rejection of 97.8%, a water flux of 11.8Lm(-2)h(-1), a MWCO of 800Da and corresponding pore size of 0.69nm, while for its uncross-linked membrane named M-U, a MgCl2 rejection of 91.2%, a water flux of 13.5Lm(-2)h(-1), a MWCO with 960Da and a pore size of 0.77nm were found. Furthermore, the M-C-BPADGE membrane exhibited selectivities of 16.0 for separation of mixed Mg(2+) and Na(+) cations, much larger than selectivity of 5.2 obtained for M-U, suggesting that the cross-linked membranes are promising in cation separation. PMID:26606594

  9. (Benzoylamino)methyl 4-Hydroxybenzoate

    OpenAIRE

    Kristina Mladenovska; Emil Popovski

    2010-01-01

    (Benzoylamino)methyl 4-hydroxybenzoate (“Benzamidomethylparaben”) (3) was obtained from a reaction of 4-hydroxybenzoic acid (2) with a dioxane suspension of (benzamidomethyl)triethylammonium chloride (1). The phenolic group in 2 cannot be benzamidomethylated with 1 in aqueous media.

  10. 1,6-Bis(4-vinylphenyl)hexane as a crosslinking agent for the preparation of crosslinked sulfonated poly(ether ether ketone) membranes by EB irradiation

    International Nuclear Information System (INIS)

    In order to mitigate problems associated with highly sulfonated aromatic hydrocarbon membranes, such as dimensional stability, mechanical strength, and methanol crossover, sulfonated poly(ether ether ketone) (SPEEK) membranes containing 1,6-bis(4-vinylphenyl)hexane (BVPH) were crosslinked by EB irradiation. Compared to the pristine SPEEK membrane, the crosslinked membranes exhibited significantly improved dimensional stability, chemical stability, and mechanical strength. The crosslinking procedure slightly reduced the proton conductivity of the membranes. The crosslinking of SPEEK with BVPH was also found to slightly reduce the proton conductivity of the membranes, but significantly reduced the methanol permeability. - Highlights: • 1,6-Bis(4-vinylphenyl)hexane (BVPH) was prepared as a crosslinking agent. • Sulfonated poly(ether ether ketone) was crosslinked using BVPH via EB irradiation. • The crosslinked membranes showed greatly improved dimensional and chemical stability. • The crosslinking process only slightly decreased the proton conductivity. • The crosslinked membranes exhibited substantially reduced methanol permeability

  11. A convenient procedure for the synthesis of allyl and benzyl ethers from alcohols and phenols

    Indian Academy of Sciences (India)

    H Surya Prakash Rao; S P Senthilkumar

    2001-06-01

    Allyl and benzyl ethers of alcohols can be prepared conveniently and in high yield with allyl and benzyl bromide in the presence of solid potassium hydroxide without use of any solvent. Phenols can be converted to allyl ethers but are inert to benzylation under above conditions.

  12. AN EVALUATION OF THE HUMAN CARCINOGENIC POTENTIAL OF ETHYLENE GLYCOL BUTYL ETHER: INTERIM FINAL POSITION PAPER

    Science.gov (United States)

    In order to determine the merit of a petition to remove ethylene glycol ether (EGBE) from the Agency's Hazardous Air Pollutant (HAP) list, EPA has developed an interim final position paper, An Evaluation of the Human Carcinogenic Potential of Ethylene Glycol Butyl Ether, t...

  13. Aspects of reaction of N-oxide radical with ethers in 13C NMR spectrum

    International Nuclear Information System (INIS)

    The stable radical N-oxide 2,2,6,6-tetramethylpiperidine was dissolved in ethers. The 13C NMR spectra were recorded in the temperature 313K at the frequency 22,625 MHz on the spectrometers with Fourier transformation. The dissolution of the radical in ether caused the contact shifts in NMR spectra. The shifts were measured. (A.S.)

  14. SOLUTION EFFECTS ON CESIUM COMPLEXATION WITH CALIXARENE CROWN ETHERS FROM LIQUID TO SUPERCRITICAL FLUIDS

    Science.gov (United States)

    Calixarene-crown ethers with rigid skeletons are superior to flexible crown ethers for separation of 137Cs from high level waste (HLW). However, this extraction methodology often requires undesirable solvents and the extraction efficiency is strongly dependent on the solvent pol...

  15. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of disodium maleate, allyl... New Uses for Specific Chemical Substances § 721.7000 Polymer of disodium maleate, allyl ether, and... substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide...

  16. Electronic transport in methylated fragments of DNA

    Science.gov (United States)

    de Almeida, M. L.; Oliveira, J. I. N.; Lima Neto, J. X.; Gomes, C. E. M.; Fulco, U. L.; Albuquerque, E. L.; Freire, V. N.; Caetano, E. W. S.; de Moura, F. A. B. F.; Lyra, M. L.

    2015-11-01

    We investigate the electronic transport properties of methylated deoxyribonucleic-acid (DNA) strands, a biological system in which methyl groups are added to DNA (a major epigenetic modification in gene expression), sandwiched between two metallic platinum electrodes. Our theoretical simulations apply an effective Hamiltonian based on a tight-binding model to obtain current-voltage curves related to the non-methylated/methylated DNA strands. The results suggest potential applications in the development of novel biosensors for molecular diagnostics.

  17. Electronic transport in methylated fragments of DNA

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, M. L. de; Oliveira, J. I. N.; Lima Neto, J. X.; Gomes, C. E. M.; Fulco, U. L., E-mail: umbertofulco@gmail.com; Albuquerque, E. L. [Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Freire, V. N. [Departamento de Física, Universidade Federal do Ceará, 60455-760 Fortaleza, CE (Brazil); Caetano, E. W. S. [Instituto Federal de Educação, Ciência e Tecnologia do Ceará, 60040-531 Fortaleza, CE (Brazil); Moura, F. A. B. F. de; Lyra, M. L. [Instituto de Física, Universidade Federal de Alagoas, 57072-900 Maceió-AL (Brazil)

    2015-11-16

    We investigate the electronic transport properties of methylated deoxyribonucleic-acid (DNA) strands, a biological system in which methyl groups are added to DNA (a major epigenetic modification in gene expression), sandwiched between two metallic platinum electrodes. Our theoretical simulations apply an effective Hamiltonian based on a tight-binding model to obtain current-voltage curves related to the non-methylated/methylated DNA strands. The results suggest potential applications in the development of novel biosensors for molecular diagnostics.

  18. Radiation-induced cationic polymerization of vinyl ethers in solution

    International Nuclear Information System (INIS)

    The influences of the polymerization media, the monomer and solvent concentrations and the temperature on the radiation-induced polymerization of isopropyl vinyl ether (IPVE) have been studied in detail under super-dry conditions. Rates of polymerization were measured and estimates of the rate constants of polymerization were calculated according to the simplified Hayashi-Williams equation. A comparison of the results with those previously reported for ethyl vinyl ether (EVE) is made. The much higher reactivity of IPVC in low polar solvents is interpreted by a drastic reduction of the polymer intramolecular solvation of the growing chain ends. This is ascribed to the bulkiness of the isopropyl side-chain groups. The radiation-induced polymerization of IPVE in bulk and in various solvents with different physical and solvating properties was studied. This was to obtain further information on the kinetics and the mechanisms involved with this monomer and also the role of the polymerization media. The influence of the monomer and solvent concentrations and of the polymerization temperature on the rate of polymerization have also been investigated. (author)

  19. A model survey meter using undoped poly (ether sulfone)

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hidehito, E-mail: hidehito@rri.kyoto-u.ac.jp [Kyoto University, 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shirakawa, Yoshiyuki [National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kanayama, Masaya; Sato, Nobuhiro [Kyoto University, 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Kitamura, Hisashi [National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Takahashi, Sentaro [Kyoto University, 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan)

    2015-04-21

    The large region surrounding the damaged Fukushima Daiichi Nuclear Power Plant has necessitated the use of numerous radiation survey meters with large, robust substrates. The survey meters require efficient scintillation materials that do not require doping and have dimensional stability, such as poly (ether sulfone) (PES) resins. Here, we demonstrate the performance of a model survey meter that uses large PES plates with polished, mirrored surfaces and rough, scattering surfaces. Light collection efficiencies from plates having one or more of these surfaces were quantitatively Characterised with {sup 36}Cl-, {sup 60}Co-, {sup 137}Cs-radioactive sources. The count rates of plates having a combination of mirrored/scattering-surfaces are >1.6 times that for plates having two mirrored surfaces. In addition, a significant amount of radiation-induced light generated in the PES is trapped inside the plate because of its relatively high refractive index. The results indicate that large, undoped PES plates can be used in radiation survey meters. - highlights: • Undoped poly (ether sulfone) (PES) can be used as a scintillation material in radiation survey meters. • Large PES plates with treated surfaces were characterized. • Surface roughening of the plates increased light collection efficiency. • Plates with a combination of mirrored/scattering surfaces work best. • A significant amount of light generated by radiation remains in the PES plates.

  20. Novel Ordered Crown Ether-Containing Polyimides for Ion Conduction

    Science.gov (United States)

    Irvin, Jennifer A.; Stasko, Daniel; Fallis, Stephen; Guenthner, Andrew J.; Webber, Cynthia; Blackwell, John; Chvalun, Sergei N.

    2003-01-01

    We report the synthesis and characterization of thermally-stable polyimides for use as battery and fuel cell electrolyte membranes. Dianhydrides used were 1,4,5,8- naphthalenetetracarboxylic dianhydride and/or 4,4'-(hexafluoroisopropylidene)diphthalic anhydride. Diamines used were anti-4,4-diaminodibenzo-l8-crown-6, 4,4'- diaminodibenzo-24-crown-8, 2,2-bis(4-aminophenyl)hexafluoropropane, and/or 2,5- diaminobenzenesulfonic acid. The polymers were characterized using electrochemical impedance spectroscopy (EIS), thermal analysis and X-ray diffraction. Polymers containing the hexafluoroisopropylidene (HFIP) group were soluble in common organic solvents, while polymers without the HFIP group were very poorly soluble. Sulfonation yields polymers that are sparingly soluble in aqueous base and/or methanol. Degree of sulfonation, determined by titration, was between one and three sulfonate groups per repeat unit. Proton conductivity was determined as a function of water content, with a maximum conductivity of l x 10(exp -2) per centimeter when fully hydrated. Crown ether-containing polymers exhibit a high degree of order that may be indicative of crown ether channel formation, which may facilitate Li(+) transport for use in battery membranes.

  1. Diphytanyl glycerol ether distributions in sediments of the Orca Basin

    Science.gov (United States)

    Pease, Tamara K.; Van Vleet, Edward S.; Barre, Jill S.

    1992-09-01

    Archaebacterially produced diphytanyl glycerol ether (DPGE) was examined in core sediments from the Orca Basin, an anoxic hypersaline basin in the northwestern Gulf of Mexico, to observe its spatial variability and potential origin. A differential extraction protocol was employed to quantify the isopranyl glycerol ethers associated with unbound, intermediate-bound, and kerogen-bound lipid fractions. Archaebacterial lipids were evident at all depths for the unbound and intermediate-bound fractions. Concentrations of DPGE ranged from 0.51 to 2.91 μg/g dry sediment at the surface and showed secondary maxima deeper in basin sediments. Intermediate-bound DPGE concentrations exhibited an inverse relationship to unbound DPGE concentrations. Kerogen-bound DPGE concentrations were normally below detection limits. Earlier studies describing the general homogeneity of lipid components within the overlying brine and at the brine/seawater interface suggest that the large-scale sedimentary DPGE variations observed in this study result from spatial and temporal variations in in situ production by methanogenic or extremely halophilic archaebacteria.

  2. Crystal structure and thermal property of polyethylene glycol octadecyl ether

    International Nuclear Information System (INIS)

    Highlights: ► The crystal structure of C18En for n ≥ 20 is a monoclinic system. ► Polyethylene glycol octadecyl ether crystallizes perfectly. ► The number of repeat units has significant effect on the melting, crystallizing temperature and enthalpy. ► The thermal stable temperature increases rapidly with increasing the number of repeat unit. - Abstract: The crystal structure, phase change property and thermal stable temperature (Td) of polyethylene glycol octadecyl ether [HO(CH2CH2O)nC18H37, C18En] with various numbers of repeat units (n = 2, 10, 20 and 100) as phase change materials (PCMs) were investigated using temperature variable Fourier transformed infrared spectroscopy (FTIR), wide-angle X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). C18En crystallizes perfectly at 0 °C; and the crystal structure for n ≥ 20 is a monoclinic system. The number of repeat units has great effect on the phase change properties of C18En. The thermal stable temperature increases rapidly with increasing the number of repeat units. They approach to that of PEG-2000 as the number of repeat units is more than 10. Td increases rapidly with increasing the number of repeat units. C18En are a series of promising polymeric PCMs

  3. Sorption-desorption behavior of polybrominated diphenyl ethers in soils

    International Nuclear Information System (INIS)

    Polybrominated diphenyl ethers (PBDEs) are flame retardants that are commonly found in commercial and household products. These compounds are considered persistent organic pollutants. In this study, we used 4,4'-dibromodiphenyl ether (BDE-15) as a model compound to elucidate the sorption and desorption behavior of PBDEs in soils. The organic carbon-normalized sorption coefficient (KOC) of BDE-15 was more than three times higher for humin than for bulk soils. However, pronounced desorption hysteresis was obtained mainly for bulk soils. For humin, increasing concentration of sorbed BDE-15 resulted in decreased desorption. Our data illustrate that BDE-15 and probably other PBDEs exhibit high sorption affinity to soils. Moreover, sorption is irreversible and thus PBDEs can potentially accumulate in the topsoil layer. We also suggest that although humin is probably a major sorbent for PBDEs in soils, other humic materials are also responsible for their sequestration. - Highlights: → BDE-15 exhibited pronounced desorption hysteresis. → BDE-15 sowed higher sorption affinity to humin as compared to the bulk soils. → Sequestration of PBDEs depends on soil organic matter constitutes other than humin. - Pronounced desorption hysteresis was observed for BDE-15 in natural soils.

  4. Crystal structure and thermal property of polyethylene glycol octadecyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Jie-yun; Tang, Xiao-fen; Li, Wei; Shi, Hai-feng [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, School of Material Science and Engineering, Tianjin Polytechnic University, Tianjin 300387 (China); Zhang, Xing-xiang, E-mail: zhangpolyu@yahoo.com.cn [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, School of Material Science and Engineering, Tianjin Polytechnic University, Tianjin 300387 (China)

    2013-04-20

    Highlights: ► The crystal structure of C18En for n ≥ 20 is a monoclinic system. ► Polyethylene glycol octadecyl ether crystallizes perfectly. ► The number of repeat units has significant effect on the melting, crystallizing temperature and enthalpy. ► The thermal stable temperature increases rapidly with increasing the number of repeat unit. - Abstract: The crystal structure, phase change property and thermal stable temperature (T{sub d}) of polyethylene glycol octadecyl ether [HO(CH{sub 2}CH{sub 2}O){sub n}C{sub 18}H{sub 37}, C18En] with various numbers of repeat units (n = 2, 10, 20 and 100) as phase change materials (PCMs) were investigated using temperature variable Fourier transformed infrared spectroscopy (FTIR), wide-angle X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). C18En crystallizes perfectly at 0 °C; and the crystal structure for n ≥ 20 is a monoclinic system. The number of repeat units has great effect on the phase change properties of C18En. The thermal stable temperature increases rapidly with increasing the number of repeat units. They approach to that of PEG-2000 as the number of repeat units is more than 10. T{sub d} increases rapidly with increasing the number of repeat units. C18En are a series of promising polymeric PCMs.

  5. Developmental toxicity of diphenyl ether herbicides in nestling American kestrels.

    Science.gov (United States)

    Hoffman, D J; Spann, J W; LeCaptain, L J; Bunck, C M; Rattner, B A

    1991-11-01

    Beginning the day after hatching, American kestrel (Falco sparverius) nestlings were orally dosed for 10 consecutive days with 5 microliters/g of corn oil (controls) or one of the diphenyl ether herbicides (nitrofen, bifenox, or oxyfluorfen) at concentrations of 10, 50, 250, or 500 mg/kg in corn oil. At 500 mg/kg, nitrofen resulted in complete nestling mortality, bifenox in high (66%) mortality, and oxyfluorfen in no mortality. Nitrofen at 250 mg/kg reduced nestling growth as reflected by decreased body weight, crown-rump length, and bone lengths including humerus, radius-ulna, femur, and tibiotarsus. Bifenox at 250 mg/kg had less effect on growth than nitrofen, but crown-rump, humerus, radius-ulna, and femur were significantly shorter than controls. Liver weight as a percent of body weight increased with 50 and 250 mg/kg nitrofen. Other manifestations of impending hepatotoxicity following nitrofen ingestion included increased hepatic GSH peroxidase activity in all nitrofen-treated groups, and increased plasma enzyme activities for ALT, AST, and LDH-L in the 250-mg/kg group. Bifenox ingestion resulted in increased hepatic GSH peroxidase activity in the 50- and 250-mg/kg groups. Nitrofen exposure also resulted in an increase in total plasma thyroxine (T4) concentration. These findings suggest that altricial nestlings are more sensitive to diphenyl ether herbicides than young or adult birds of precocial species. PMID:1942122

  6. A model survey meter using undoped poly (ether sulfone)

    International Nuclear Information System (INIS)

    The large region surrounding the damaged Fukushima Daiichi Nuclear Power Plant has necessitated the use of numerous radiation survey meters with large, robust substrates. The survey meters require efficient scintillation materials that do not require doping and have dimensional stability, such as poly (ether sulfone) (PES) resins. Here, we demonstrate the performance of a model survey meter that uses large PES plates with polished, mirrored surfaces and rough, scattering surfaces. Light collection efficiencies from plates having one or more of these surfaces were quantitatively Characterised with 36Cl-, 60Co-, 137Cs-radioactive sources. The count rates of plates having a combination of mirrored/scattering-surfaces are >1.6 times that for plates having two mirrored surfaces. In addition, a significant amount of radiation-induced light generated in the PES is trapped inside the plate because of its relatively high refractive index. The results indicate that large, undoped PES plates can be used in radiation survey meters. - highlights: • Undoped poly (ether sulfone) (PES) can be used as a scintillation material in radiation survey meters. • Large PES plates with treated surfaces were characterized. • Surface roughening of the plates increased light collection efficiency. • Plates with a combination of mirrored/scattering surfaces work best. • A significant amount of light generated by radiation remains in the PES plates

  7. Sorption-desorption behavior of polybrominated diphenyl ethers in soils

    Energy Technology Data Exchange (ETDEWEB)

    Olshansky, Yaniv; Polubesova, Tamara [Department of Soil and Water Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel); Vetter, Walter [Institute of Food Chemistry (170b), University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart (Germany); Chefetz, Benny, E-mail: chefetz@agri.huji.ac.il [Department of Soil and Water Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel)

    2011-10-15

    Polybrominated diphenyl ethers (PBDEs) are flame retardants that are commonly found in commercial and household products. These compounds are considered persistent organic pollutants. In this study, we used 4,4'-dibromodiphenyl ether (BDE-15) as a model compound to elucidate the sorption and desorption behavior of PBDEs in soils. The organic carbon-normalized sorption coefficient (K{sub OC}) of BDE-15 was more than three times higher for humin than for bulk soils. However, pronounced desorption hysteresis was obtained mainly for bulk soils. For humin, increasing concentration of sorbed BDE-15 resulted in decreased desorption. Our data illustrate that BDE-15 and probably other PBDEs exhibit high sorption affinity to soils. Moreover, sorption is irreversible and thus PBDEs can potentially accumulate in the topsoil layer. We also suggest that although humin is probably a major sorbent for PBDEs in soils, other humic materials are also responsible for their sequestration. - Highlights: > BDE-15 exhibited pronounced desorption hysteresis. > BDE-15 sowed higher sorption affinity to humin as compared to the bulk soils. > Sequestration of PBDEs depends on soil organic matter constitutes other than humin. - Pronounced desorption hysteresis was observed for BDE-15 in natural soils.

  8. Developmental toxicity of diphenyl ether herbicides in nestling American kestrels

    Science.gov (United States)

    Hoffman, D.J.; Spann, J.W.; LeCaptain, L.J.; Bunck, C.M.; Rattner, B.A.

    1991-01-01

    Beginning the day after hatching, American kestrel (Falco sparverius) nestlings were orally dosed for 10 consecutive days with 5 microliters/g of corn oil (controls) or one of the diphenyl ether herbicides (nitrofen, bifenox, or oxyfluorfen) at concentrations of 10, 50, 250, or 500 mg/kg in corn oil. At 500 mg/kg, nitrofen resulted in complete nestling mortality, bifenox in high (66%) mortality, and oxyfluorfen in no mortality. Nitrofen at 250 mg/kg reduced nestling growth as reflected by decreased body weight, crownrump length, and bone lengths including humerus, radiusulna, femur, and tibiotarsus. Bifenox at 250 mg/kg had less effect on growth than nitrofen, but crownrump, humerus, radiusulna, and femur were significantly shorter than controls. Liver weight as a percent of body weight increased with 50 and 250 mg/kg nitrofen. Other manifestations of impending hepatotoxicity following nitrofen ingestion included increased hepatic GSH peroxidase activity in all nitrofentreated groups, and increased plasma enzyme activities for ALT, AST, and LDHL in the 250mg/kg group. Bifenox ingestion resulted in increased hepatic GSH peroxidase activity in the 50and 250mg/kg groups. Nitrofen exposure also resulted in an increase in total plasma thyroxine (T4) concentration. These findings suggest that altricial nestlings are more sensitive to diphenyl ether herbicides than young or adult birds of precocial species.

  9. Silica-based nanocomposite membranes via the sol gel process of polyethoxysiloxane within a sulfonated poly(ether-ether-ketone) matrix: morphology and proton mobility

    OpenAIRE

    Colicchio, Irene

    2009-01-01

    This thesis deals with the preparation and characterization of hybrid organic/inorganic membranes obtained from solutions, where the organic phase is the sulfonated poly(ether ether ketone) (SPEEK) and the inorganic phase are silica nanoparticles obtained from the in situ "water free" sol-gel process of polyethoxysiloxane (PEOS). PEOS is a soluble and liquid hyperbranched polymer of low viscosity synthesized in our laboratories via a one pot reaction between tetraethoxysilane (TEOS) and aceti...

  10. Practical Preparation of (4R,5R,E-methyl 5-(tert-butyldimethylsilyloxy-4-hydroxyhepta-2,6-dienoate

    Directory of Open Access Journals (Sweden)

    Yudhi Dwi Kurniawan

    2013-10-01

    Full Text Available This study is aimed to improve the preparation of uselful synthetic block (4R,5R,E-methyl 5-(tert-butyldimethylsilyloxy-4-hydroxyhepta-2,6-dienoate (1. This intermediate was used in the synthesis of (+-Cladospolide D. The strategy developed by Voigtritter et al. was adopted to exploit the acceleration effect of copper (I iodide. This compound was prepared from D-mannitol-derived dienediol (2 coupled with methyl acrylate through olefin cross-metathesis reaction in various conditions. It was found that performing the reaction in the presence of 3 mol% of CuI in refluxing diethyl ether gave the product up to 75% of yield with lower catalyst loading, i.e.: 2 mol%.

  11. Rational Design of Cesium-Selective Ionophores and Chemosensors: Dihydrocalix[4]arene Crown-6 Ethers

    Energy Technology Data Exchange (ETDEWEB)

    Sachleben, Richard A.; Bryan, Jeffrey C.; Brown, Gilbert M.; Engle, Nancy L.; Haverlock, Tamara J.; Hay, Benjamin P.; Urvoas, Agathe; Moyer, Bruce A.

    2003-12-15

    Molecular mechanics calculations performed on calix[4]arene crown-6 ethers predict that the 1,3-dihydro derivatives will exhibit greater complementarity for potassium and cesium ions than the parent 1,3-dialkoxy calix crowns. The X-ray crystal structures of 1,3-alt bis-octyloxycalix[4]arene benzocrown-6 ether, dihydrocalix[4]arene benzocrown-6 ether, and the cesium nitrate complex of dihydrocalix[4]arene benzocrown-6 ether were determined. The cesium complex structure corresponds closely to the structure predicted by molecular mechanics. The dihydrocalix[4]arene crown-6 ethers exhibit enhanced cesium selectivity in the extraction of alkali metal salts and provide a platform for a highly sensitive and selective cesium chemosensor.

  12. Phytochemical comparison between Pet ether and ethanolic extracts of Bacopa monnieri, Evolvulus alsinoides and Tinospora cordifolia.

    Science.gov (United States)

    Gupta, Avneet; Raj, Hem; Sharma, Bhartendu; Upmanyu, Neeraj

    2014-04-01

    Bacopa monnieri, Evolvulus alsinoides and Tinospora cordifolia are established ayurvedic herbs having neuropharmacological effect. In present study is aimed to Phytochemical Comparison between Pet ether and Ethanolic extracts of Bacopa monnieri (BME), Evolvulus alsinoides (EAE) and Tinospora cordifolia (TCE). To identify the presence (+) or absence (-) of different phytoconstituents in Pet ether and Ethanolic extracts of BME, EAE and TCE by using various phytochemical testing methods. Phytochemical investigation showed the presence of various phytochemical constituents in Pet ether and Ethanolic extracts of BME, EAE and TCE. When comparison between Pet ether and Ethanolic extracts of BME, EAE and TCE; Ethanolic extracts of these plants showed more phytoconstituents as compared to Pet ether extracts of these plants. From present investigation, it can be concluded that phytochemical comparison is subsequently momentous and useful in finding chemical constituents in the plant substances that may lead to their quantitative evaluation and also pharmacologically active chemical compounds. PMID:25911854

  13. Mutual solubility in the system uranyl trifluoroacetate--water--diethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Vdovenko, V.M.; Baluev, A.V.; Suglobova, I.G.

    1975-01-01

    A study was made of mutual solubility in the system uranyl trifluoroacetate--water--diethyl ether at 25/sup 0/C. It was found that uranyl trifluoroacetate, like the trichloroacetate which was investigated previously, is extracted by diethyl ether much better than uranyl nitrate over a wide range of concentrations. The solubility of UO/sub 2/(CF/sub 3/COO)/sub 2/ in ether depends strongly on the water content of the system. While the anhydrous salt is practically insoluble, the addition of two H/sub 2/O molecules to a molecule of UO/sub 2/(CF/sub 3/COO)/sub 2/ leads to an increase in solubility to approximately 75 wt. percent. On the basis of the ir spectra of ether solutions of uranyl trifluoroacetate in the presence of semiheavy water (HDO) it was established that the hydration envelope of the complex in diethyl ether has a layer structure.

  14. Metal ion complexation by ionizable crown ethers. Progress report, January 1, 1991--December 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, R.A.

    1993-07-01

    Cyclic and acyclic polyether compounds with pendent carboxylic acid, phosphonic acid monoethyl ester, sulfonic acid, phosphinic acid and hydroxamic acid groups have been synthesized. The proton-ionizable polyethers can come with and without lipophilic groups. Two types of lipophilic di-ionizable lariat ethers have been prepared. Conformations of proton-ionizable lariat ethers have been probed. Competitive alkali metal cation transport by syn-(decyl)dibenzo-16-crown-5-oxyacetic acid and lipophilic proton-ionizable dibenzo lariat ethers in polymer-supported liquid membranes was studied. Complexation of alkali metal cations with ionized lariat ethers was studied. Condensation polymerization of cyclic and acyclic dibenzo polyethers containing pendent mono-ionizable groups with formaldehyde produces novel ion exchange resins with both ion exchange sites for metal ion complexation and polyether binding sites for metal ion recognition. Resins prepared from lariat ether dibenzo phosphonic acid monoethyl esters show strong sorption of divalent heavy metal cations with selectivity for Pb{sup 2+}.

  15. Halogen derivatives of benzo- and dibenzocrown ethers: synthesis, structure, properties and application

    Science.gov (United States)

    Pluzhnik-Gladyr, S. M.

    2016-02-01

    Methods of synthesis of halogenated benzo- and dibenzocrown ether derivatives are surveyed: halogenation of benzo- and dibenzocrown ethers with molecular halogens, N-halosuccinimides in the solid phase and different media (water, ethanol, halohydrocarbons) and hypohalites in water, as well as the 'assembly' method. Reactions of these compounds are considered: synthesis of phosphorus-containing crown ethers, organometallic synthesis, the Heck and Sonogashira reactions, synthesis of acetylene derivatives and other reactions. Special attention is focused on the complexing properties of halogenated benzocrown ethers with respect to ionic guests and neutral organic molecules. The possibility of synthesis of complexes of such compounds in the solid phase is demonstrated. The extraction and sorption properties of halogenated benzo- and dibenzocrown ethers are considered. Examples of practical use of these compounds are presented. The bibliography includes 203 references.

  16. A method of communication between EPICS IOC and EtherCAT devices%EPICS IOC与EtherCAT设备通信的一种方法

    Institute of Scientific and Technical Information of China (English)

    何泳成; 王春红; 吴煊

    2014-01-01

    EtherCAT (Ethemet Control Automation Technology)是一种用于工业自动化的实时以太网现场总线协议.通过使用OPC (Object Linking and Embedding for Process Control) Gateway驱动程序实现了EPICS(Experimental Physics and Industrial Control System) IOC (Input/Output Controller)与EtherCAT设备的通信,从而使EtherCAT成为加速器控制系统中对实时性要求很高的高速控制系统的一种解决方案.在简要介绍EPICS、EtherCAT、OPC及OPC Gateway的基础上,对使用OPC Gateway驱动程序实现EPICS IOC与EtherCAT设备通信进行了测试.结果表明,EPICS IOC可通过OPC Gateway驱动程序与EtherCAT设备正常通信.

  17. Hydroxylated and methoxylated polybrominated diphenyl ethers in long-tailed ducks (Clangula hyemalis) and their main food, Baltic blue mussels (Mytilus trossulus × Mytilus edulis).

    Science.gov (United States)

    Dahlberg, Anna-Karin; Chen, Vivian Lindberg; Larsson, Kjell; Bergman, Åke; Asplund, Lillemor

    2016-02-01

    Long-tailed ducks (Clangula hyemalis) that breed in northern Europe and western Siberia and commonly winter in the Baltic Sea, are threatened by a significant population decrease. The ducks are, by primarily feeding on Baltic blue mussels (Mytilus trossulus × Mytilus edulis) while wintering in the Baltic Sea, potentially subjected to high levels of toxic hydroxylated polybrominated diphenyl ethers (OH-PBDEs). To assess long-tailed ducks exposure to polybrominated phenols (PBPs), polybrominated anisoles (PBAs), hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methylated counterparts (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs), livers of ten long-tailed ducks wintering in the Baltic Sea were analysed. Pattern and levels of analytes in long-tailed ducks (liver) and blue mussels sampled in March and May at nine sites in the Baltic Sea were compared. The geometric mean concentration (ng/g l.w.) in livers of long-tailed ducks and Baltic blue mussels were: Σ(2)PBPs: 0.57 and 48; Σ(2)PBAs: 0.83 and 11; Σ(7)OH-PBDEs: 6.1 and 45; Σ(7)MeO-PBDEs: 3.8 and 69; Σ(7)PBDEs: 8.0 and 7.2, respectively. Based on an estimated daily intake of 450 g fresh blue mussel meat, long-tailed ducks daily dietary intake of brominated substances while foraging in the Baltic Sea in March-May was estimated to; 390 ng Σ(2)PBPs, 90 ng Σ(2)PBAs, 370 ng Σ(7)OH-PBDEs, 590 ng Σ(7)MeO-PBDEs and 59 ng Σ(7)PBDEs. The low levels of PBPs, PBAs, OH-PBDEs and MeO-PBDEs in the long-tailed duck livers compared to blue mussel, despite a continuous daily intake, suggest that these compounds are poorly retained in long-tailed ducks. PMID:26495833

  18. Polybrominated Diphenyl Ethers Alter Hepatic Phosphoenolpyruvate Carboxykinase Enzyme Kinetics in Male Wistar Rats: Implications for Lipid and Glucose Metabolism

    Science.gov (United States)

    Polybrominated diphenyl ethers (PBDE) are a family of lipophilic brominated flame-retardants consisting of 209 possible congeners. Three PBDE commercially-produced mixtures are decabrominated diphenyl ether (e.g. deca-BDE or DE-83R); octabrominated diphenyl ether (e.g. octa-BDE o...

  19. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    Science.gov (United States)

    2010-07-01

    ... glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols polyglycidyl ethers (generic name). 721.6980... Substances § 721.6980 Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky... reporting. (1) The chemical substance dimer acids, polymer with polyalkylene glycol, bisphenol...

  20. Biosynthesis of ether-phospholipids including plasmalogens, peroxisomes and human disease: new insights into an old problem

    NARCIS (Netherlands)

    R.J.A. Wanders; P. Brites

    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