Science.gov

Sample records for isopropyl ether

  1. Effect of solvents on the radiation-induced polymerization of ethyl and isopropyl vinyl ethers

    SciTech Connect

    Hsieh, W.C.

    1981-01-01

    The effect of solvents on the radiation-induced cationic polymerization of ethyl and isopropyl vinyl ethers (EVE and IPVE, respectively) was investigated. EVE and IPVE polymerizations were carried out in bulk and in solution under superdry conditions in which polar impurities, especially water, have been reduced to negligible levels. This was accomplished by means of a sodium mirror technique using joint free baked out glass equipment and high vacuum. Plots of the monomer conversions and irradiation times were obtained for EVE and IPVE polymerizations in bulk and in benzene solution at constant monomer concentrations. The monomer concentration dependence of the polymerization rate was studied for EVE polymerization in bulk and in benzene, diethlyl ether, diglyme and methylene chloride, and for IPVE polymerization in bulk and in benzene. Solvent effect on the estimated propagating rate constants was examined for EVE and IPVE polymerization in bulk and in solution. The effect of temperature on the polymerization rate was also investigated for EVE polymerization in bulk ad in benzene, diethyl and diisopropyl ethers, methylene chloride and nitromethane, and for IPVE ploymerization in bulk and in benzene.

  2. 21 CFR 173.240 - Isopropyl alcohol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Isopropyl alcohol. 173.240 Section 173.240 Food... Related Substances § 173.240 Isopropyl alcohol. Isopropyl alcohol may be present in the following foods... the presence of the isopropyl alcohol and provides for the use of the hops extract only as...

  3. 21 CFR 173.240 - Isopropyl alcohol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Isopropyl alcohol. 173.240 Section 173.240 Food... Solvents, Lubricants, Release Agents and Related Substances § 173.240 Isopropyl alcohol. Isopropyl alcohol... label of the hops extract specifies the presence of the isopropyl alcohol and provides for the use...

  4. 21 CFR 173.240 - Isopropyl alcohol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Isopropyl alcohol. 173.240 Section 173.240 Food and..., Lubricants, Release Agents and Related Substances § 173.240 Isopropyl alcohol. Isopropyl alcohol may be... label of the hops extract specifies the presence of the isopropyl alcohol and provides for the use...

  5. 21 CFR 173.240 - Isopropyl alcohol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Isopropyl alcohol. 173.240 Section 173.240 Food... Solvents, Lubricants, Release Agents and Related Substances § 173.240 Isopropyl alcohol. Isopropyl alcohol... label of the hops extract specifies the presence of the isopropyl alcohol and provides for the use...

  6. 21 CFR 173.240 - Isopropyl alcohol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Isopropyl alcohol. 173.240 Section 173.240 Food... Solvents, Lubricants, Release Agents and Related Substances § 173.240 Isopropyl alcohol. Isopropyl alcohol... label of the hops extract specifies the presence of the isopropyl alcohol and provides for the use...

  7. [Development of identification method for isopropyl citrate].

    PubMed

    Furusho, Noriko; Ohtsuki, Takashi; Tatebe-Sasaki, Chiye; Kubota, Hiroki; Sato, Kyoko; Akiyama, Hiroshi

    2014-01-01

    In Japan's Specification and Standards for Food Additive, 8th edition, two identification tests involving isopropyl citrate for detecting isopropyl alcohol and citrate are stipulated. However, these identification tests use mercury compound, which is toxic, or require a time-consuming pretreatment process. To solve these problems, an identification test method using GC-FID for detecting isopropyl alcohol was developed. In this test, a good linearity was observed in the range of 0.1-40 mg/mL of isopropyl alcohol. While investigating the pretreatment process, we found that isopropyl alcohol could be detected using GC-FID in the distillation step only, without involving any reflux step. The study also showed that the citrate moiety of isopropyl citrate was identified using the solution remaining after conducting the distillation of isopropyl alcohol. The developed identification tests for isopropyl citrate are simple and use no toxic materials. PMID:25707204

  8. [Development of identification method for isopropyl citrate].

    PubMed

    Furusho, Noriko; Ohtsuki, Takashi; Tatebe-Sasaki, Chiye; Kubota, Hiroki; Sato, Kyoko; Akiyama, Hiroshi

    2014-01-01

    In Japan's Specification and Standards for Food Additive, 8th edition, two identification tests involving isopropyl citrate for detecting isopropyl alcohol and citrate are stipulated. However, these identification tests use mercury compound, which is toxic, or require a time-consuming pretreatment process. To solve these problems, an identification test method using GC-FID for detecting isopropyl alcohol was developed. In this test, a good linearity was observed in the range of 0.1-40 mg/mL of isopropyl alcohol. While investigating the pretreatment process, we found that isopropyl alcohol could be detected using GC-FID in the distillation step only, without involving any reflux step. The study also showed that the citrate moiety of isopropyl citrate was identified using the solution remaining after conducting the distillation of isopropyl alcohol. The developed identification tests for isopropyl citrate are simple and use no toxic materials.

  9. Isopropyl methyl phosphonic acid (IMPA)

    Integrated Risk Information System (IRIS)

    Isopropyl methyl phosphonic acid ( IMPA ) ; CASRN 1832 - 54 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assess

  10. 21 CFR 582.6386 - Isopropyl citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Isopropyl citrate. 582.6386 Section 582.6386 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Isopropyl citrate. (a) Product. Isopropyl citrate. (b) Tolerance. This substance is generally recognized...

  11. 21 CFR 582.6386 - Isopropyl citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Isopropyl citrate. 582.6386 Section 582.6386 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Isopropyl citrate. (a) Product. Isopropyl citrate. (b) Tolerance. This substance is generally recognized...

  12. 21 CFR 184.1386 - Isopropyl citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Isopropyl citrate. 184.1386 Section 184.1386 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1386 Isopropyl citrate. (a) Isopropyl citrate is a mixture...

  13. 27 CFR 21.113 - Isopropyl alcohol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Isopropyl alcohol. 21.113 Section 21.113 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants §...

  14. 27 CFR 21.113 - Isopropyl alcohol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Isopropyl alcohol. 21.113 Section 21.113 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants §...

  15. 27 CFR 21.113 - Isopropyl alcohol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Isopropyl alcohol. 21.113 Section 21.113 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants §...

  16. 27 CFR 21.113 - Isopropyl alcohol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Isopropyl alcohol. 21.113 Section 21.113 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants §...

  17. 27 CFR 21.113 - Isopropyl alcohol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Isopropyl alcohol. 21.113 Section 21.113 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants §...

  18. 21 CFR 184.1386 - Isopropyl citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... § 184.1(b)(1), the ingredient is used in food with no limitation other than current good manufacturing practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human food... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Isopropyl citrate. 184.1386 Section 184.1386...

  19. 21 CFR 184.1386 - Isopropyl citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... § 184.1(b)(1), the ingredient is used in food with no limitation other than current good manufacturing practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human food... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Isopropyl citrate. 184.1386 Section 184.1386...

  20. 21 CFR 184.1386 - Isopropyl citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... § 184.1(b)(1), the ingredient is used in food with no limitation other than current good manufacturing practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human food... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Isopropyl citrate. 184.1386 Section 184.1386...

  1. Ether production

    SciTech Connect

    Harandi, M.N.; Owen, H.

    1991-05-14

    This patent describes a multistage process for etherifying a mixed C{sub 4} + olefinic hydrocarbon feedstock containing isoalkene. It comprises: contacting the olefinic feedstock and aliphatic alcohol in a first reaction stage under partial etherification conditions with a regenerable inorganic metal oxide acid solid catalyst to convert a major amount of the isoalkene to C{sub 5} + tertiary-alkyl ether; recovering a reactant effluent from the first stage containing ether product, unreacted alcohol and unreacted olefin including isoalkene; charging the first stage effluent to a second stage catalytic distillation column containing solid acid resin etherification catalyst in a plurality of fixed bed catalysis-distillation zones to complete substantially full etherification of isoalkene; recovering C{sub 5} + ether as a liquid from the catalytic distillation column; regenerating the first stage catalyst to remove feedstock impurity and coke and to acid activity; and continuing ether production with regenerated catalyst.

  2. Tetrabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Tetrabromodiphenyl ether ; CASRN 40088 - 47 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncar

  3. Pentabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Pentabromodiphenyl ether ; CASRN 32534 - 81 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncar

  4. Hexabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Hexabromodiphenyl ether ; CASRN 36483 - 60 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarc

  5. Ethyl ether

    Integrated Risk Information System (IRIS)

    Ethyl ether ; CASRN 60 - 29 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  6. Octabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Octabromodiphenyl ether ; CASRN 32536 - 52 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarc

  7. Tribromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Tribromodiphenyl ether ; CASRN 49690 - 94 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  8. Nonabromodiphenyl ether

    Integrated Risk Information System (IRIS)

    Nonabromodiphenyl ether ; CASRN 63936 - 56 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarc

  9. Coexistence Curve of Perfluoromethylcyclohexane-Isopropyl Alcohol

    NASA Technical Reports Server (NTRS)

    Jacobs, D. T.; Kuhl, D. E.; Selby, C. E.

    1996-01-01

    The coexistence curve of the binary fluid mixture perfluoromethylcyclohexane-isopropyl alcohol was determined by precisely measuring the refractive index both above and below its upper critical consolute point. Sixty-seven two-phase data points were obtained over a wide range of reduced temperatures, 10(exp -5) less than t less than 2.5 x 10(exp -1), to determine the location of the critical point: critical temperature=89.901 C, and critical composition = 62.2% by volume perfluoromethylcyclohexane. These data were analyzed to determine the critical exponent 8 close to the critical point, the amplitude B, and the anomaly in the diameter. The volume-fraction coexistence curve is found to be as symmetric as any composition like variable. Correction to scaling is investigated as well as the need for a crossover theory. A model is proposed that describes the asymptotic approach to zero of the effective exponent Beta, which allows an estimation of the temperature regime free of crossover effects.

  10. Ethanol-based cleanser versus isopropyl alcohol to decontaminate stethoscopes.

    PubMed

    Lecat, Paul; Cropp, Elliott; McCord, Gary; Haller, Nairmeen Awad

    2009-04-01

    Approximately 1 in 20 hospital admissions is complicated by a health care-associated infection. Stethoscopes may play a role in spreading nosocomial infections. The objective of this study was to determine the effectiveness of an ethanol-based cleanser (EBC) compared with isopropyl alcohol pads in reducing bacterial contamination of stethoscope diaphragms. Stethoscopes were cultured from medical professionals on 4 medical floors before and after cleaning with either EBC or isopropyl alcohol pads. The numbers of colony-forming units (cfu) grown were compared between the 2 cleaners and to baseline values. A total of 99 stethoscopes were cultured (49 EBC; 50 isopropyl alcohol), and all were positive for growth. After cleaning, 28.28% of the stethoscopes were growth-free (12 EBC; 16 isopropyl alcohol). Cleaning with EBC and isopropyl alcohol pads significantly reduced the cfu counts (by 92.8% and 92.5%, respectively), but neither was found to be statistically superior (F = 1.22; P = .2721). Cleaning a stethoscope diaphragm using either EBC or isopropyl alcohol led to a significant reduction in bacterial growth in culture. As an extension of the hand, a stethoscope should be cleaned with the same frequency as the hands. The simultaneous cleaning of hands and stethoscope may further increase compliance with current standards.

  11. Thermodynamics of Hydrogen Production from Dimethyl Ether Steam Reforming and Hydrolysis

    SciTech Connect

    T.A. Semelsberger

    2004-10-01

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

  12. Prenyl Ethers: Novel Fungal Volatiles Formed by Penicillium digitatum.

    PubMed

    Amrein, Thomas M; Frey, Peter; Meier, Roberto; Baumann, Heidi; Tanner, Miriam; Gassenmeier, Klaus F

    2014-10-01

    Prenyl ethyl ether (PEE) was previously described as the cause for a solvent-like off-note in ground hazelnuts, but its origin remained unclear. Investigations were carried out by analytical groups of Coop and Givaudan over four years to elucidate this phenomenon. From mouldy citrus fruits a strain of Penicillium digitatum was isolated and found to form PEE. Formation on citrus and other fruits was prominent and contributed to the particular smell of decayed fruits. Several strains of P. digitatum formed PEE, while other fungal species did not. In contrast to citrus fruit, prenyl methyl ether (PME) was formed as dominant prenyl ether on hazelnuts while only small amounts of PEE were found. PME has not been previously described as volatile metabolite of fungi or as a food-taint. Spiking experiments with deuterated ethanol showed that the ethyl group is likely incorporated into PEE via the aldehyde form. On hazelnuts strongly decayed by P. digitatum yet another prenyl ether was tentatively identified: Prenyl isopropyl ether. Prenyl ethers present a novel group of volatile metabolites of P. digitatum. They are likely typical for this species and have not been described before. Prenyl ethers seem to play a significant role in the smell of food decayed by P. digitatum and should be considered in cases of off-notes and taints. PMID:25437159

  13. Digit switch evaluations and capillary IPA (isopropyl alcohol) study

    SciTech Connect

    Mizik, P.M.; Kibalo, E.F.

    1990-12-01

    Capillary flow of isopropyl alcohol under the wire insulation of an eleven-wire cable dissolved trapped flux from the pretinning and soldering operations and caused it to deposit on the circuit board inside a digit switch. Conformal coatings were successful in sealing the wire insulation gap to prevent solvent flow. 16 figs., 2 tabs.

  14. Oven Evaporates Isopropyl Alcohol Without Risk Of Explosion

    NASA Technical Reports Server (NTRS)

    Morgan, Gene E.; Hoult, William S.

    1996-01-01

    Ordinary convection oven with capacity of 1 ft.(sup3) modified for use in drying objects washed in isopropyl alcohol. Nitrogen-purge equipment and safety interlocks added to prevent explosive ignition of flammable solvent evaporating from object to be dried.

  15. Solid-supported acids as mild and versatile reagents for the deprotection of aromatic ethers.

    PubMed

    Ploypradith, Poonsakdi; Cheryklin, Pannarin; Niyomtham, Nattisa; Bertoni, Daniel R; Ruchirawat, Somsak

    2007-07-01

    p-Toluene sulfonic acid (p-TsOH) immobilized either on polystyrene (PS) or silica (Si) was found to be effective in cleaving aromatic ethers containing isopropyl, tert-butyl, allyl, and benzyl groups, as well as mono-, di-, and trimethoxylated benzyl groups, in moderate to excellent yields (54-95%). These protecting groups could be selectively deprotected when they were simultaneously present on the same or different aromatic rings in a substrate.

  16. Poly(arylene ether)s containing pendent ethynyl groups

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Jensen, Brian J. (Inventor)

    1996-01-01

    Poly(arylene ether)s containing pendent ethynyl and substituted ethynyl groups and poly(arylene ether) copolymers containing pendent ethynyl and substituted ethynyl groups are readily prepared from bisphenols containing ethynyl and substituted ethynyl groups. The resulting polymers are cured up to 350.degree. C. to provide crosslinked poly(arylene ether)s with good solvent resistance, high strength and modulus.

  17. Rate constant calculations of H-atom abstraction reactions from ethers by HȮ2 radicals.

    PubMed

    Mendes, Jorge; Zhou, Chong-Wen; Curran, Henry J

    2014-02-27

    In this work, we detail hydrogen atom abstraction reactions from six ethers by the hydroperoxyl radical, including dimethyl ether, ethyl methyl ether, propyl methyl ether, isopropyl methyl ether, butyl methyl ether, and isobutyl methyl ether, in order to test the effect of the functional group on the rate constant calculations. The Møller-Plesset (MP2) method with the 6-311G(d,p) basis set has been employed in the geometry optimizations and frequency calculations of all of the species involved in the above reaction systems. The connections between each transition state and the corresponding local minima have been determined by intrinsic reaction coordinate calculations. Energies are reported at the CCSD(T)/cc-pVTZ level of theory and include the zero-point energy corrections. As a benchmark in the electronic energy calculations, the CCSD(T)/CBS extrapolation was used for the reactions of dimethyl ether + HȮ2 radicals. A systematic calculation of the high-pressure limit rate constants has been performed using conventional transition-state theory, including asymmetric Eckart tunneling corrections, in the temperature range of 500-2000 K. The one dimensional hindrance potentials obtained at MP2/6-311G(d,p) for the reactants and transition states have been used to describe the low frequency torsional modes. Herein, we report the calculated individual, average, and total rate constants. A branching ratio analysis for every reaction site has also been performed. PMID:24483837

  18. Radiation chemistry of alternative fuel oxygenates -- Substituted ethers

    SciTech Connect

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

    1999-11-15

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

  19. Conversion of alcohols to ether-rich gasoline

    SciTech Connect

    Harandi, M.N.; Owen, H.

    1991-08-20

    This patent describes a continuous process for converting crude methanol to methyl tertiary-alkyl ether. It comprises contacting a crude methanolic feedstock containing a minor amount of water with a liquid olefinic C{sub 4}-C{sub 5} hydrocarbon extraction stream rich in C{sub 4} or C{sub 5} iso-alkene hydrocarbon or mixtures thereof under extraction conditions favorable to selective extraction of the methanol, thereby providing an extract liquid stream containing sufficient methanol for etherification and an aqueous raffinate stream lean in methanol; reacting liquid hydrocarbon extractant and extracted methanol substantially free of water in a first catalytic reaction zone in contact with acid etherification catalyst under etherification process conditions to convert methanol and iso-alkene hydrocarbon to predominantly methyl tertiary-alkyl ether; fractionating the etherification effluent to recover liquid product containing methyl tertiary-alkyl ether; catalytically converting methanol in the raffinate stream at elevated temperature in contact with acid zeolite catalyst to produce predominantly lower olefins rich in propene, isobutylene and isoamylenes; reacting propene from methanol conversion with water to product di-isopropyl ether; and recovering the isobutylene and isoamylenes produced by catalytic conversion of methanol in a C{sub 4}-C{sub 5} liquid stream for recycle as liquid extractant.

  20. The Hydrolysis of Di-Isopropyl Methylphosphonate in Ground Water

    SciTech Connect

    Sega, G.A., Tomkins, B.A., Griest, W.H., Bayne, C.K.

    1997-12-31

    Di-isopropyl methylphosphonate (DIMP) is a byproduct from the manufacture of the nerve agent Sarin. The persistence of DIMP in the ground water is an important question in evaluating the potential environmental impacts of DIMP contamination. The half-life of DIMP in ground water at 10 deg C was estimated to be 500 years with a 95% confidence interval of 447 to 559 years from measurements of the hydrolysis rates at temperatures between 70 to 98 deg C.Extrapolation of the kinetics to 10 deg C used the Arrhenius equation, and calculation of the half-life assumed first-order kinetics. Inorganic phosphate was not detected.

  1. Crown ethers in graphene

    SciTech Connect

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I.; Gallego, Nidia C.; Pantelides, Sokrates T.; Pennycook, Stephen J.; Moyer, Bruce A.; Chisholm, Matthew F.

    2014-11-13

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basic structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.

  2. Crown ethers in graphene

    DOE PAGES

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I.; Gallego, Nidia C.; Pantelides, Sokrates T.; Pennycook, Stephen J.; Moyer, Bruce A.; Chisholm, Matthew F.

    2014-11-13

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basicmore » structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.« less

  3. Grunwald-Winstein Analysis - Isopropyl Chloroformate Solvolysis Revisited

    PubMed Central

    D’Souza, Malcolm J.; Reed, Darneisha N.; Erdman, Kevin J.; Kyong, Jin Burm; Kevill, Dennis N.

    2009-01-01

    Specific rates of solvolysis at 25 °C for isopropyl chloroformate (1) in 24 solvents of widely varying nucleophilicity and ionizing power, plus literature values for studies in water and formic acid, are reported. Previously published solvolytic rate constants at 40.0 °C are supplemented with two additional values in the highly ionizing fluoroalcohols. These rates are now are analyzed using the one and two-term Grunwald-Winstein Equations. In the more ionizing solvents including ten fluoroalcohols negligible sensitivities towards changes in solvent nucleophilicity (l) and very low sensitivities towards changes in solvent ionizing power (m) values are obtained, evocative to those previously observed for 1-adamantyl and 2-adamantyl chloroformates 2 and 3. These observations are rationalized in terms of a dominant solvolysis-decomposition with loss of the CO2 molecule. In nine of the more nucleophilic pure alchohols and aqueous solutions an association-dissociation mechanism is believed to be operative. Deficiencies in the acid production indicate 2-33% isopropyl chloride formation, with the higher values in less nucleophilic solvents. PMID:19399225

  4. 40 CFR 180.437 - Methyl 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-p-toluate and methyl 6-(4-isopropyl-4...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Methyl 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-p-toluate and methyl 6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-m-toluate; tolerances for residues. 180.437 Section 180.437 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS...

  5. Catalytic oxidation of dimethyl ether

    DOEpatents

    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.

  6. Evolution of electrical discharge channel in isopropyl alcohol solution

    NASA Astrophysics Data System (ADS)

    Panov, V. A.; Vasilyak, L. M.; Pecherkin, V. Ya; Vetchinin, S. P.; Kulikov, Yu M.; Son, E. E.

    2015-11-01

    Evolution of the spark channel created by the high voltage pulse generator in 15% isopropyl alcohol solution in tap water was investigated experimentally. Fast camera images show the start of spark discharge channel with the anode region glowing, which is due to ionization-overheating instability near the surface of anode electrode. Measured propagation velocity is about 4 m/s and points to thermal process of channel evolution. Partial discharges in gas bubbles near the spark channel were observed. When the channel bridges the gap the cathode flash of lightning occurs which is much brighter than anode glowing and channel one. After destruction of the spark channel the cathode glowing stays for a longer period than anode one.

  7. Isopropyl alcohol tank installed at A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    2009-01-01

    An isopropyl alcohol (IPA) tank is lifted into place at the A-3 Test Stand being built at NASA's John C. Stennis Space Center. Fourteen IPA, water and liquid oxygen (LOX) tanks are being installed to support the chemical steam generators to be used on the A-3 Test Stand. The IPA and LOX tanks will provide fuel for the generators. The water will allow the generators to produce steam that will be used to reduce pressure inside the stand's test cell diffuser, enabling operators to simulate altitudes up to 100,000 feet. In that way, operators can perform the tests needed on rocket engines being built to carry humans back to the moon and possibly beyond. The A-3 Test Stand is set for completion and activation in 2011.

  8. Rotational Investigation of the Adducts of Formic Acid with Alcohols, Ethers and Esters

    NASA Astrophysics Data System (ADS)

    Evangelisti, Luca; Spada, Lorenzo; Li, Weixing; Caminati, Walther

    2016-06-01

    Mixtures of formic acid with methyl alcohol, with isopropyl alcohol, with tert-butyl alcohol, with dimethylether and with isopropylformiate have been supersonically expanded as pulsed jets. The obtained cool plumes have been analyzed by Fourier transform microwave spectroscopy. It has been possible to assign the rotational spectra of the 1:1 adducts of formic acid with tert-butyl alcohol, with dimethyl ether and with isopropylformiate. The conformational shapes and geometries of these adducts, as well as the topologies of their itermolecular hydrogen bonds will be presented. An explanation is given of the failure of the assignments of the rotational spectra of the adducts of formic acid with methyl alcohol and isopropyl alcohol.

  9. Hugoniot and Shock Initiation Studies of Isopropyl Nitrate

    NASA Astrophysics Data System (ADS)

    Sheffield, S. A.; Davis, L. L.; Baer, M. R.; Engelke, Ray; Alcon, R. R.; Renlund, A. M.

    2002-07-01

    Isopropyl nitrate (IPN) is a liquid explosive of rather low energy. We have measured the sound speed and used it in the universal liquid Hugoniot to produce an estimated Hugoniot for this material. Gas-gun-driven, multiple-magnetic-gauge measurements were made to measure a Hugoniot state at 6 GPa; it was in good agreement with the prediction. Two similar experiments were conducted at higher pressure inputs to study the shock-to-detonation transition in IPN; the high inputs required for initiation necessitated the use of a two-stage gun. One experiment with an input of 9.0 GPa into the IPN produced a run to detonation of about 3 mm and the in-situ particle velocity profiles showed the expected homogeneous initiation behavior of a growing wave behind the shock front that overtakes the front and decays to a steady detonation. The reactive wave in the shocked IPN appears to have achieved a steady superdetonation in both of the initiation experiments. This is the first time a steady superdetonation has been measured with in-situ gauges.

  10. Chloromethyl methyl ether (CMME)

    Integrated Risk Information System (IRIS)

    Chloromethyl methyl ether ( CMME ) ; CASRN 107 - 30 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments fo

  11. Triethylene glycol monoethyl ether

    Integrated Risk Information System (IRIS)

    Triethylene glycol monoethyl ether ; CASRN 112 - 50 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments fo

  12. Triethylene glycol monobutyl ether

    Integrated Risk Information System (IRIS)

    Triethylene glycol monobutyl ether ; CASRN 143 - 22 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments fo

  13. p-Bromodiphenyl ether

    Integrated Risk Information System (IRIS)

    p - Bromodiphenyl ether ; CASRN 101 - 55 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  14. Propylene glycol monoethyl ether

    Integrated Risk Information System (IRIS)

    Propylene glycol monoethyl ether ; CASRN 52125 - 53 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments fo

  15. Propenyl ether monomers for photopolymerization

    DOEpatents

    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.

  16. Propenyl ether monomers for photopolymerization

    DOEpatents

    Crivello, J.V.

    1996-10-22

    Propenyl ether monomers of formula A(OCH{double_bond}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 the above formula 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.

  17. Subclinical Increased Anterior Stromal Reflectivity With Topical Taprenepag Isopropyl

    PubMed Central

    Schachar, Ronald A.; Raber, Susan; Thomas, Kristina V.; Benetz, Beth Ann M.; Szczotka-Flynn, Loretta B.; Zhang, Min; Howell, Scott J.; Lass, Jonathan H.

    2016-01-01

    Purpose To assess the effect of topical taprenepag isopropyl on each layer of the cornea by confocal microscopy. Methods Thirty-two ocular hypertensive or glaucoma patients were randomized into a 2-period, crossover study of 14 days of 0.1% taprenepag alone and in unfixed combination with 0.005% latanoprost (combination therapy). Baseline and sequential slit-lamp biomicroscopy, fluorescein staining, central ultrasonic pachymetry, and confocal microscopy were performed. Confocal images were analyzed for the density of the central superficial and basal epithelium, midstromal keratocytes, and endothelium, as well as endothelial coefficient of variation and percentage of hexagonal cells, and reflectivity of anterior stromal and midstromal layers. Results Corneal staining increased from baseline, reaching a peak at day 13 (69% and 63% of subjects treated with monotherapy and combination therapy, respectively), which resolved by day 35. A statistically significant increase in mean corneal thickness for both eyes and both treatments occurred on days 7 and 13 (range, 20–27 μm; P < 0.001) but recovered (≤6 μm) by day 35. No statistically significant changes were observed in the basal epithelial, midstromal, or endothelial cells. Mean ratio of average reflectivity of anterior stroma to midstroma increased on days 13 and 35 in period 1 for each treatment (range, 1.2–1.9; P < 0.001), and this increase persisted during period 2. Conclusions Anterior stromal reflectivity may remain increased even when biomicroscopic and confocal images of corneal layers remain normal or have recovered after topical taprenepag. This subclinical measure may be useful to detect a persistent adverse effect of a topical agent on the cornea. PMID:22549238

  18. Ether and hydrocarbon production

    SciTech Connect

    Harandi, M.N.; Owen, H.

    1991-03-19

    This patent describes a continuous process for converting lower aliphatic alkanol and olefinic hydrocarbon to alkyl tertiary-alkyl ethers and C{sub 5} + gasoline boiling range hydrocarbons. It comprises contacting alkanol and a light olefinic hydrocarbon stream rich in isobutylene and other C{sub 4} isomeric hydrocarbons under iso-olefin etherification conditions in an etherification reaction zone containing acid etherification catalyst; separating etherification effluent to recover a light stream comprising unreacted alkanol and light olefinic hydrocarbon and a liquid product stream containing alkyl tertiary-butyl ether; and contacting the light stream with acidic, medium pore metallosilicate catalyst under alkanol and hydrocarbon conversion conditions whereby C{sub 5} + gasoline boiling range hydrocarbons are produced.

  19. Poly(arylene ether)s That Resist Atomic Oxygen

    NASA Technical Reports Server (NTRS)

    Connell, John W.; Hergenrother, Paul; Smith, Joseph G., Jr.

    1994-01-01

    Novel poly(arylene ether)s containing phosphine oxide (PAEPO's) made via aromatic nucleophilic displacement reactions of activated aromatic dihalides (or, in some cases, activated aromatic dinitro compounds) with new bisphenol monomers containing phosphine oxide. Exhibited favorable combination of physical and mechanical properties and resistance to monatomic oxygen in oxygen plasma environment. Useful as adhesives, coatings, films, membranes, moldings, and composite matrices.

  20. Comprehensive Analysis of Interstellar Iso-PROPYL Cyanide up to 480 GHZ

    NASA Astrophysics Data System (ADS)

    Kolesniková, Lucie; Alonso, E. R.; Cabezas, Carlos; Mata, Santiago; Alonso, José L.

    2016-06-01

    Iso-propyl cyanide, also known as iso-butyronitrile, is a branched alkyl molecule recently detected in the interstellar medium. A combination of Stark-modulated microwave spectroscopy and frequency-modulated millimeter and submillimeter wave spectroscopy was used to analyze its rotational spectrum from 26 to 480 GHz. Spectral assignments and analysis include transitions from the ground state, eight excited vibrational states and 13C isotopologues. Results of this work should facilitate astronomers further observations of iso-propyl cyanide in the interstellar medium. A. Belloche, R. T. Garrod, H. S. P. Müller, K. M. Menten, Science, 2014, 345, 1584

  1. Comparison of isopropyl alcohol and trichloroethylene in removing solder flux: Topical report

    SciTech Connect

    Benkovich, M.G.

    1988-01-01

    This work evaluated a nontoxic solvent for its ability to remove solder flux as compared to trichloroethylene solvent. Isopropyl alcohol was evaluated for its cleaning efficiency for solder flux removal using a high pressure spray process (minimum spray pressure of 80 psig). Cleanliness levels were measured by the Meseran Surface Analyzer. Test samples also underwent gas chromatograph/mass spectrometer Analysis and were visually inspected under a longwave ultraviolet lamp. Detailed analyses of flux removal by the two solvents were made as related to solder flux types, solder flux diluted by 50% with isopropyl alcohol, and solder process conditions. 2 refs., 2 figs., 12 tabs.

  2. X-ray diffraction investigation of 1-phenyl-3-isopropyl-5-(benzothiazol-2-yl)formazan

    SciTech Connect

    Slepukhin, P. A. Pervova, I. G.; Rezinskikh, Z. G.; Lipunova, G. N.; Gorbatenko, Yu. A.; Lipunov, I. N.

    2008-01-15

    The crystal structure of 1-phenyl-3-isopropyl-5-(benzothiazol-2-yl)formazan is investigated using X-ray diffraction. The compound crystallizes in the form of two crystallographically independent molecules (A and B) in identical conformations that are stabilized by intermolecular hydrogen bonds. The intermolecular hydrogen bonds N-H-N (N-N, 2.892 and 2.939 A) link molecules into AB dimers. Both molecules have a flattened structure, except for the isopropyl fragment. The bonds in the formazan chains are delocalized. Molecules A and B have close geometric characteristics.

  3. 21 CFR 177.2280 - 4,4′-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 4,4â²-Isopropyl-idenedi-phenol-epichloro-hydrin...,4′-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins. 4,4... applicable to 4,4′-isopropylidenedi-phenol-epichlorohydrin resins listed in other sections of parts 174,...

  4. Polyarylene Ethers with Improved Properties

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M. (Inventor); Jensen, B. J. (Inventor); Havens, S. J. (Inventor)

    1986-01-01

    This invention relates to novel polyarylene ethers which possess the combination of high strength, toughness, and high use temperature with ease of extrusion and formation into complex objects. These polyarylene ethers are suitable for use in adhesives, coatings, films, membranes, and composite matrices. The polyarylene ethers of this invention are the polycondensation products from the reaction of either 1,3-bis (4-chloro or fluorobenzoyl) benzene with any one of the following bisphenolic compounds: bis (3-hydroxyphenyl) methane; bis (4-hydroxyphenyl) methane; 1,1-dimethyl-bis (4-hydroxyphenyl)methane, or 9,9-bis (4-hydroxyphenyl) fluorene. Random and block copolymers are also comprehended.

  5. Biodegradation of gasoline ether oxygenates.

    PubMed

    Hyman, Michael

    2013-06-01

    Ether oxygenates such as methyl tertiary butyl ether (MTBE) are added to gasoline to improve fuel combustion and decrease exhaust emissions. Ether oxygenates and their tertiary alcohol metabolites are now an important group of groundwater pollutants. This review highlights recent advances in our understanding of the microorganisms, enzymes and pathways involved in both the aerobic and anaerobic biodegradation of these compounds. This review also aims to illustrate how these microbiological and biochemical studies have guided, and have helped refine, molecular and stable isotope-based analytical approaches that are increasingly being used to detect and quantify biodegradation of these compounds in contaminated environments.

  6. Chemoselective Deprotection of Triethylsilyl Ethers

    PubMed Central

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

    2009-01-01

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

  7. Imide/arylene ether copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor); Hergenrother, Paul M. (Inventor); Bass, Robert G. (Inventor)

    1992-01-01

    Imide/arylene ether block copolymers are prepared by reacting anhydride terminated poly(amic acids) with amine terminated poly(arylene ethers) in polar aprotic solvents and by chemically or thermally cyclodehydrating the resulting intermediate poly(amic acids). The resulting block copolymers have one glass transition temperature or two, depending upon the particular structure and/or the compatibility of the block units. Most of these block copolymers form tough, solvent resistant films with high tensile properties.

  8. Rearrangements of Cycloalkenyl Aryl Ethers.

    PubMed

    Törincsi, Mercedesz; Nagy, Melinda; Bihari, Tamás; Stirling, András; Kolonits, Pál; Novak, Lajos

    2016-01-01

    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. PMID:27104504

  9. Space, Time, Ether, and Kant

    NASA Astrophysics Data System (ADS)

    Wong, Wing-Chun Godwin

    This dissertation focused on Kant's conception of physical matter in the Opus postumum. In this work, Kant postulates the existence of an ether which fills the whole of space and time with its moving forces. Kant's arguments for the existence of an ether in the so-called Ubergang have been acutely criticized by commentators. Guyer, for instance, thinks that Kant pushes the technique of transcendental deduction too far in trying to deduce the empirical ether. In defense of Kant, I held that it is not the actual existence of the empirical ether, but the concept of the ether as a space-time filler that is subject to a transcendental deduction. I suggested that Kant is doing three things in the Ubergang: First, he deduces the pure concept of a space-time filler as a conceptual hybrid of the transcendental object and permanent substance to replace the category of substance in the Critique. Then he tries to prove the existence of such a space-time filler as a reworking of the First Analogy. Finally, he takes into consideration the empirical determinations of the ether by adding the concept of moving forces to the space -time filler. In reconstructing Kant's proofs, I pointed out that Kant is absolutely committed to the impossibility of action-at-a-distance. If we add this new principle of no-action-at-a-distance to the Third Analogy, the existence of a space-time filler follows. I argued with textual evidence that Kant's conception of ether satisfies the basic structure of a field: (1) the ether is a material continuum; (2) a physical quantity is definable on each point in the continuum; and (3) the ether provides a medium to support the continuous transmission of action. The thrust of Kant's conception of ether is to provide a holistic ontology for the transition to physics, which can best be understood from a field-theoretical point of view. This is the main thesis I attempted to establish in this dissertation.

  10. Sulfonimide-containing poly(arylene ether)s and poly(arylene ether sulfone)s, methods for producing the same, and uses thereof

    DOEpatents

    Hofmann, Michael A.

    2006-11-14

    The present invention is directed to sulfonimide-containing polymers, specifically sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, and processes for making the sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, for use conductive membranes and fuel cells.

  11. Detection of a branched alkyl molecule in the interstellar medium: iso-propyl cyanide

    NASA Astrophysics Data System (ADS)

    Belloche, Arnaud; Garrod, Robin T.; Müller, Holger S. P.; Menten, Karl M.

    2014-09-01

    The largest noncyclic molecules detected in the interstellar medium (ISM) are organic with a straight-chain carbon backbone. We report an interstellar detection of a branched alkyl molecule, iso-propyl cyanide (i-C3H7CN), with an abundance 0.4 times that of its straight-chain structural isomer. This detection suggests that branched carbon-chain molecules may be generally abundant in the ISM. Our astrochemical model indicates that both isomers are produced within or upon dust grain ice mantles through the addition of molecular radicals, albeit via differing reaction pathways. The production of iso-propyl cyanide appears to require the addition of a functional group to a nonterminal carbon in the chain. Its detection therefore bodes well for the presence in the ISM of amino acids, for which such side-chain structure is a key characteristic.

  12. Interplay of phenol and isopropyl isomerism in propofol from broadband chirped-pulse microwave spectroscopy.

    PubMed

    Lesarri, Alberto; Shipman, Steven T; Neill, Justin L; Brown, Gordon G; Suenram, Richard D; Kang, Lu; Caminati, Walther; Pate, Brooks H

    2010-09-29

    The conformational equilibrium of the general anesthetic propofol (2,6-diisopropylphenol) has been studied in a supersonic expansion using broadband chirped-pulse microwave spectroscopy. Three conformers originated by the combined internal rotation of the hydroxyl and the two isopropyl groups have been detected in the jet-cooled rotational spectrum. The most stable conformer exhibits tunneling splittings associated with the internal rotation of the hydroxyl group, from which we determined the torsional potential and barrier heights (905-940 cm(-1)). The carbon backbone structure was derived from the spectral assignments of all 12 (13)C monosubtituted isotopologues in natural abundance and confirmed a plane-symmetric gauche orientation of the two isopropyl groups (Gg) for this conformer. In the other two detected conformers (EG and GE) one of the isopropyl groups is eclipsed with respect to the ring plane while the other is gauche, differing in a ∼180° rotation of the hydroxyl group. Supporting ab initio calculations provided information on the potential energy surface and molecular properties of the title compound.

  13. Study the density, ultrasonic and compressibility of binary mixture of aqueous solution of isopropyl alcohol and mustard oil

    NASA Astrophysics Data System (ADS)

    Monupal, Suthar, B.

    2016-05-01

    The ultrasonic velocities, compressibility and bulk modulus of binary mixtures of aqueous solution of isopropyl alcohol with mustard oil have been measured at different concentrations at room temperature. The results are varied with the concentration in such a way i.e. ultrasonic velocity and Bulk Modulus is decreases with the increase in concentration and compressibility is increases with the increase in concentration of aqueous isopropyl alcohol. It is due to molecular interactions present in the mixtures.

  14. Ether resistance in Drosophila melanogaster.

    PubMed

    Deery, B J; Parsons, P A

    1972-01-01

    Strains set up from single inseminated females of D. melanogaster from the wild differ in their resistance to the anaesthetics, ether and chloroform. The main differences between four selected extreme strains could be explained by additive genes, which in the case of ether resistance were located to regions of chromosomes 2 and 3. The lack of correspondence between ether and chloroform resistance between strains indicates that although the type of genetic architecture controlling the traits is similar, the actual genes differ, which is reasonable in view of their differing chemical structures. Quite high heritabilities were found for resistance to ether based on five inbred strains. No significant associations between resistance to ether and body weight, developmental rate or longevity were found.It is clear that resistance to both anaesthetics would be amenable to more detailed genetic analyses. It is pointed out that the general conclusions reached from such studies will have implications with respect to the effect of chemicals such as insecticides, not naturally present in nature.

  15. Ethereal embodiment of cancer patients.

    PubMed

    van der Riet, P

    1999-10-01

    Ethereal embodiment is the attending and focusing on the body through discourses such as meditation, visualisation and massage, and the experiencing a new sense of the embodied being as balanced, connected, centred and of being made whole. This paper continues a previous article titled 'Massaged embodiment of cancer patients'. Data from my doctoral studies are analysed utilising crucial concepts of poststructuralism such as subjectivity, discourse, power and history to examine ethereal embodiment. This paper will address the advantages of visualisation and discusses the link between spirituality, embodiment, and memory.

  16. Grignard Reactions in "Wet" Ether

    NASA Astrophysics Data System (ADS)

    Smith, David H.

    1999-10-01

    A small laboratory ultrasonic bath can be used to initiate the Grignard reaction of alkyl or aryl bromides in regular laboratory-quality, undried, diethyl ether and in simple undried test tubes. The reaction typically starts within 30 to 45 seconds and is self-sustaining. Yields and products are the same as obtained with carefully dried ether and equipment. We normally run this reaction at the 1.5-gram scale, but the procedure can be scaled up to at least 10 g of the bromide.

  17. 21 CFR 868.5420 - Ether hook.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ether hook. 868.5420 Section 868.5420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5420 Ether hook. (a) Identification. An ether hook is a...

  18. 21 CFR 868.5420 - Ether hook.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ether hook. 868.5420 Section 868.5420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5420 Ether hook. (a) Identification. An ether hook is a...

  19. 21 CFR 868.5420 - Ether hook.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ether hook. 868.5420 Section 868.5420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5420 Ether hook. (a) Identification. An ether hook is a...

  20. 21 CFR 868.5420 - Ether hook.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ether hook. 868.5420 Section 868.5420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5420 Ether hook. (a) Identification. An ether hook is a...

  1. 21 CFR 868.5420 - Ether hook.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ether hook. 868.5420 Section 868.5420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5420 Ether hook. (a) Identification. An ether hook is a...

  2. 40 CFR 721.3364 - Aliphatic ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aliphatic ether. 721.3364 Section 721... Aliphatic ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an aliphatic ether (PMN P-93-1381) is subject to reporting under...

  3. 40 CFR 721.3374 - Alkylenediolalkyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylenediolalkyl ether. 721.3374... Substances § 721.3374 Alkylenediolalkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an alkylenediolalkyl ether (PMN P-93-362) is subject...

  4. 40 CFR 721.3374 - Alkylenediolalkyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylenediolalkyl ether. 721.3374... Substances § 721.3374 Alkylenediolalkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an alkylenediolalkyl ether (PMN P-93-362) is subject...

  5. 40 CFR 721.3437 - Dialkyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Dialkyl ether. 721.3437 Section 721... Dialkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as dialkyl ether (PMN P-93-1308) is subject to reporting under this...

  6. 40 CFR 721.3380 - Anilino ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Anilino ether. 721.3380 Section 721... Anilino ether. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as anilino ether (P-83-910) is subject to reporting under this section...

  7. 40 CFR 721.3364 - Aliphatic ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aliphatic ether. 721.3364 Section 721... Aliphatic ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an aliphatic ether (PMN P-93-1381) is subject to reporting under...

  8. 40 CFR 721.3380 - Anilino ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Anilino ether. 721.3380 Section 721... Anilino ether. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as anilino ether (P-83-910) is subject to reporting under this section...

  9. 40 CFR 721.3437 - Dialkyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dialkyl ether. 721.3437 Section 721... Dialkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as dialkyl ether (PMN P-93-1308) is subject to reporting under this...

  10. Metabolism of polybrominated diphenyl ethers and tetrabromobisphenol A by fish liver subcellular fractions in vitro.

    PubMed

    Shen, Mengnan; Cheng, Jie; Wu, Ruohan; Zhang, Shenghu; Mao, Liang; Gao, Shixiang

    2012-06-15

    Polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) are two major flame retardants that accumulate in fish tissues and are potentially toxic. Their debrominated and oxidated derivatives were also reported in fish tissues although the sources of theses derivatives were unidentified. Our study was to determine whether PBDEs and TBBPA could be metabolized by fish liver subcellular fractions in vitro and to identify what types of metabolites were formed. Liver microsomes and S9 fractions of crucian carp (Carassius auratus) were exposed to 4,4'-dibromodiphenyl ether (BDE 15), 2,2',4,4'-tetrabromodiphenyl ether (BDE 47) or TBBPA solutions for 4h. Exposure of liver subcellular fractions to BDE 15 resulted in the formation of bromophenol and two monohydroxylated dibromodiphenyl ether metabolites. Neither in microsomes nor in S9 studies has revealed the presence of hydroxylated metabolites with BDE 47 exposure which indicated that the oxidation reactions in vitro were hindered by the increased number of bromine substituents on the PBDEs. TBBPA underwent an oxidative cleavage near the central carbon of the molecule, which led to the production of 2,6-dibromo-4-isopropyl-phenol and three unidentified metabolites. Another metabolite of TBBPA characterized as a hexa-brominated compound with three aromatic rings was also found in the liver subcellular fractions. These results suggest that the biotransformation of BDE 15 and TBBPA in fish liver is mediated by cytochrome P450 (CYP450) enzymes, as revealed by the formation of hydroxylated metabolites and oxidative bond cleavage products. Moreover, further studies on the identification of specific CYP450 isozymes involved in the biotransformation revealed that CYP1A was the major enzyme responsible for the biotransformation of BDE 15 and TBBPA in fish liver subcellular fractions and CYP3A4 also played a major role in metabolism of TBBPA. PMID:22417763

  11. Bis(chloroethyl)ether (BCEE)

    Integrated Risk Information System (IRIS)

    Bis ( chloroethyl ) ether ( BCEE ) ; CASRN 111 - 44 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments fo

  12. p,p\\'-Dibromodiphenyl ether

    Integrated Risk Information System (IRIS)

    p , p ' - Dibromodiphenyl ether ; CASRN 2050 - 47 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for

  13. Bis(chloromethyl)ether (BCME)

    Integrated Risk Information System (IRIS)

    Bis ( chloromethyl ) ether ( BCME ) ; CASRN 542 - 88 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments f

  14. Propylene glycol monomethyl ether (PGME)

    Integrated Risk Information System (IRIS)

    Propylene glycol monomethyl ether ( PGME ) ; CASRN 107 - 98 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assess

  15. Lacinilene C 7-methyl ether

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lacinilene C 7-methyl ether is an antimicrobial compound produced by the cotton plant in response to attack by pathogens. For the first time, we now report the crystal structure of this compound. This may prove useful in studies on the interaction of the compound with pathogenic fungal cells....

  16. Desoxyhemigossypol-6-methyl-ether

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Desoxyhemigossypol-6-methyl ether is an antimicrobial compound produced by the cotton plant in response to attack by pathogens. For the first time, we now report the crystal structure of this compound. This may prove useful in studies on the interaction of the compound with pathogenic fungal cells...

  17. Tactics for Probing Aryne Reactivity: Mechanistic Studies of Silicon-oxygen Bond Cleavage During the Trapping of (HDDA-generated) Benzynes by Silyl Ethers

    PubMed Central

    Hoye, Thomas R.; Baire, Beeraiah; Wang, Tao

    2014-01-01

    We report mechanistic aspects of the trapping of thermally (HDDA) generated benzyne derivatives by pendant silyl ether groups, which results in net insertion of the pair of benzyne Csp-hydribized carbon atoms into the silicon–oxygen sigma bond. Cross-over experiments using symmetrical, doubly labeled bis-silyl ether substrates established that the reaction is unimolecular in nature. Competition experiments involving either intramolecular or intermolecular dihydrogen transfer clock reactions (from within a TIPS isopropyl group or cyclooctane, respectively) vs. the silyl ether cyclization were used to gain additional insights. We evaluated effects of the steric bulk of the silyl ether trapping group and of the ring-size of the cyclic ether being formed (furan vs. pyran). These types of competition experiments allow the relative rates of various product-determining steps to be determined. This previously has only rarely been possible because aryne formation is typically rate-limiting, making it challenging to probe the kinetics of subsequent trapping reactions. Solvent effects (polarity of the medium) and computational studies were used to probe the question of stepwise vs. concerted pathways for the Si–O insertion. PMID:25419449

  18. Serotonin uptake in cerebral cortex cultures: imipramine-like inhibition by N-isopropyl-p-iodoamphetamine

    SciTech Connect

    de Jong, B.M.; Feenstra, M.G.; Ruijter, J.M.; van Royen, E.A.

    1989-03-01

    In cultured rat neocortex, uptake of (/sup 3/H)serotonin (5-HT) and the SPECT radiopharmaceutical N-isopropyl-p-(/sup 123/I)iodoamphetamine (IMP) was demonstrated after 4 and 14 days in vitro. Both imipramine and cold IMP inhibited (/sup 3/H)5-HT uptake. Uptake of (/sup 123/I)IMP was inhibited by imipramine but not by cold 5-HT. The similarity in the behaviors of IMP and imipramine indicates that uptake of IMP might be related to a serotonergic uptake system in a way that is similar to that in which imipramine is related to such a system.

  19. Chemical and biochemical activities of sonochemically synthesized poly(N-isopropyl acrylamide)/silica nanocomposite

    NASA Astrophysics Data System (ADS)

    Chowdhury, Pranesh; Saha, Swadhin Kr; Guha, Arun; Saha, Samar Kr

    2012-11-01

    Poly(N-isopropyl acrylamide) (PNIPA) grafted mesoporous silica nanoparticles (MPSNP) leading to novel inorganic/organic core-shell nanocomposite has been synthesized sonochemically in an aqueous medium without additives like cross-linker, hydrophobic agent, organic solvent. The colloidal stability of MPSNP is enhanced significantly due to encapsulation of the polymer. The composites are characterized by TEM, FTIR and TGA. The chemical and biochemical activities of the sonochemically synthesized materials have been studied in the light of reaction with acid-base, protein adsorption, antimicrobial activity, biocompatibility and nonthrombogenic property. Advantages of sonochemical synthesis compared to other techniques have been evaluated.

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

    PubMed

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

    PubMed

    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

  2. Chirality of and Gear Motion in Isopropyl Methyl Sulfile: a Fourier Transform Microwave Study

    NASA Astrophysics Data System (ADS)

    Kawashima, Yoshiyuki; Sakieda, Keisuke; Hirota, Eizi

    2010-06-01

    Isopropyl methyl sulfide (CH3)2CHSCH3 was investigated by Fourier transform microwave spectroscopy. Two rotational isomers gauche and trans were detected. The rotational spectra of gauche were found fit to an asymmetric rotor pattern, except for being split by the internal rotation of CH3 attached to S with the potential barrier V3 of 601.642 (65) cm-1 and for exhibiting the effect of tunneling between the two equivalent gauche forms in a few high-K transitions. The tunneling was discussed from a viewpoint of chirality. The trans spectra appeared generally similar to those of gauche, with V3 to the S-CH3 internal rotation of 559.00 (11) cm-1, but satellite lines accompanied the ground torsional state lines in some high-K transitions. These satellites were ascribed to the excited state of the C(isop)-S torsion. In fact, the potential function for this torsion was shown by an ab initio calculation to be flat or even of double minima around the trans position, which was presumably caused by a gear coupling between the two methyl groups of the isopropyl group and the one in the S-CH3.

  3. Measuring exposures to glycol ethers.

    PubMed Central

    Clapp, D E; Zaebst, D D; Herrick, R F

    1984-01-01

    In 1981, NIOSH began investigating the potential reproductive health effects resulting from exposures to a class of organic solvents known generically as glycol ethers (GE). This research was begun as a result of the NIOSH criteria document development program which revealed little data available on the health effects of glycol ether exposure. Toxicologic research was begun by NIOSH and other researchers which suggested substantial reproductive effects in animals. These animal data motivated a study of human exposures in the occupational setting. In 1981 and 1982 NIOSH conducted several walk-through surveys which included preliminary measurements of exposures in a variety of industries including painting trades, coal mining, production blending and distribution facilities, aircraft fueling, and communications equipment repair facilities. The human exposure data from these surveys is summarized in this paper with most results well below 1 parts per million (ppm) and only a few values approaching 10 ppm. Blood samples were collected at one site resulting in GE concentrations below the limit of detection. Exposures to airborne glycol ethers, in the industries investigated during the collection of this data, revealed several problems in reliably sampling GE at low concentrations. It became apparent, from the data and observations of work practices, that air monitoring alone provided an inadequate index of GE exposure. Further field studies of exposure to GE are anticipated, pending location of additional groups of exposed workers and development of more reliable methods for characterizing exposure, especially biological monitoring. PMID:6499824

  4. Influence of hydrogen on the dehydrogenation of isopropyl alcohol in the presence of a palladium membrane catalyst

    SciTech Connect

    Mikhalenko, N.N.; Gryazova, V.M.; Khrapova, E.V.

    1986-08-01

    An investigation is made of the influence of hydrogen on the dehydrogenation of isopropyl alcohol on palladium foil. It is shown that the degree of isopropanol conversion to acetone is an extreme function of the quantity of hydrogen in the reaction zone. We establish that at the experimental temperature absorption of hydrogen by the palladium foil is observed. An almost periodic change in the degree of isopropyl alcohol conversion is observed, which may be related to changes of hydrogen concentration at the surface and in the catalyst membrane layer near to the surface.

  5. Polyphenylene ethers with imide linking groups

    NASA Technical Reports Server (NTRS)

    St.clair, T. L.; Burks, H. D. (Inventor)

    1984-01-01

    Novel polyphenylene ethers with imide linking units are disclosed. These polymers incorporate the solvent and thermal resistance of polyimides and the processability of polyphenylene ethers. Improved physical properties over those of the prior art are obtained by incorporating meta linked ethers and/or polyphenylene oxides into the polymer backbone. A novel process for making polymers of this type is also disclosed. The process is unique in that the expected need of high process temperatures and/or special atmospheres are eliminated.

  6. Aza crown ether compounds as anion receptors

    DOEpatents

    Lee, H.S.; Yang, X.O.; McBreen, J.

    1998-08-04

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI{sup +} ion in alkali metal batteries. 3 figs.

  7. Aza crown ether compounds as anion receptors

    DOEpatents

    Lee, Hung Sui; Yang, Xiao-Oing; McBreen, James

    1998-08-04

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI.sup.+ ion in alkali metal batteries.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Vibrational Study Of Poly(Ether Ether Ketone).

    NASA Astrophysics Data System (ADS)

    Dosiere, M.

    1989-12-01

    The medium infrared region (4000-400cm-1) has been widely used to study crystallinity because differences could be observed in the vibrational spectrum of several polymers which could be related to crystallinity as determined by X-ray diffraction, differential scanning calorimetry and density measurements. However, as crystallinity is concerned with packing of chains and interactions between neighboor chains, the absorption bands arising from such vibrations appear therefore at wavenumbers below 400 cm -1. Poly-(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene) or poly(aryl ether ether ketone) (PEEK),commercially introduced by ICI1, has been attracting increasing interest. It is a semicrystalline polymer with an unusual combination of properties such as high chemical resistance, excellent thermal stability as good mechanical properties. Taking into account of its high temperature high strength characteristics and melt processability, PEEK is generating interest for applications such as reinforced composites, coatings, electrical connectors, impeller housings... Fourier transform infrared spectroscopy is a quick and powerful tool to investigate orientation and/or crystallinity in polymeric materials.

  10. 21 CFR 189.300 - Hydrogenated 4,4′-isopropyl-idene-diphenol-phosphite ester resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...-phosphite ester resins. 189.300 Section 189.300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Surfaces § 189.300 Hydrogenated 4,4′-isopropyl-idene-diphenol-phosphite ester resins. (a) Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins are the condensation product of 1 mole of triphenyl phosphite and...

  11. Reduced blood clearance and increased urinary excretion of N-nitrosodimethylamine in patas monkeys exposed to ethanol or isopropyl alcohol.

    PubMed

    Anderson, L M; Koseniauskas, R; Burak, E S; Moskal, T J; Gombar, C T; Phillips, J M; Sansone, E B; Keimig, S; Magee, P N; Rice, J M

    1992-03-15

    Low concentrations of N-nitrosodimethylamine are metabolized in rodent and human liver by cytochrome P450IIE1, an activity competitively inhibitable by ethanol. In rodents coadministration of ethanol with N-nitrosodimethylamine results in increased tumorigenicity in extrahepatic organs, probably as a result of reduced hepatic clearance. To test this concept in a primate, the effects of ethanol cotreatment on the pharmacokinetics of N-nitrosodimethylamine were measured in male patas monkeys. Ethanol, 1.2 g/kg given p.o. before i.v. N-nitrosodimethylamine (1 mg/kg) or concurrently with an intragastric dose resulted in a 10-50-fold increase in the area under the blood concentration versus time curves and a 4-13-fold increase in mean residence times for N-nitrosodimethylamine. Isopropyl alcohol, 3.2 g/kg 24 h before N-nitrosodimethylamine, also increased these parameters 7-10-fold; this effect was associated with persistence of isopropyl alcohol and its metabolic product acetone, both IIE1 inhibitors, in the blood. While no N-nitrosodimethylamine was detected in expired air, trace amounts were found in urine. Ethanol and isopropyl alcohol pretreatment increased the maximum urinary N-nitrosodimethylamine concentration 15-50-fold and the percentage of the dose excreted in the urine by 100-800-fold. Thus ethanol and isopropyl alcohol greatly increase systemic exposure of extrahepatic organs to N-nitrosodimethylamine in a primate.

  12. 21 CFR 177.2280 - 4,4′-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... thermo-setting epoxy resins. 177.2280 Section 177.2280 Food and Drugs FOOD AND DRUG ADMINISTRATION...,4′-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins. 4,4′-Isopropylidenediphenol-epichlo-rohydrin thermosetting epoxy resins may be safely used as articles or components...

  13. 21 CFR 189.300 - Hydrogenated 4,4′-isopropyl-idene-diphenol-phosphite ester resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-phosphite ester resins. 189.300 Section 189.300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Surfaces § 189.300 Hydrogenated 4,4′-isopropyl-idene-diphenol-phosphite ester resins. (a) Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins are the condensation product of 1 mole of triphenyl phosphite and...

  14. 21 CFR 177.2280 - 4,4′-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 4,4â²-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins. 177.2280 Section 177.2280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT...

  15. 21 CFR 177.2280 - 4,4′-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 4,4â²-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins. 177.2280 Section 177.2280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT...

  16. 21 CFR 177.2280 - 4,4′-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false 4,4â²-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins. 177.2280 Section 177.2280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use...

  17. 21 CFR 189.300 - Hydrogenated 4,4′-isopropyl-idene-diphenol-phosphite ester resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...-phosphite ester resins. 189.300 Section 189.300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...′-isopropyl-idene-diphenol-phosphite ester resins. (a) Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins are the condensation product of 1 mole of triphenyl phosphite and 1.5 moles of...

  18. 21 CFR 189.300 - Hydrogenated 4,4′-isopropyl-idene-diphenol-phosphite ester resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...-phosphite ester resins. 189.300 Section 189.300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Surfaces § 189.300 Hydrogenated 4,4′-isopropyl-idene-diphenol-phosphite ester resins. (a) Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins are the condensation product of 1 mole of triphenyl phosphite and...

  19. 21 CFR 189.300 - Hydrogenated 4,4′-isopropyl-idene-diphenol-phosphite ester resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...-phosphite ester resins. 189.300 Section 189.300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Surfaces § 189.300 Hydrogenated 4,4′-isopropyl-idene-diphenol-phosphite ester resins. (a) Hydrogenated 4,4′-isopropylidene-diphenolphosphite ester resins are the condensation product of 1 mole of triphenyl phosphite and...

  20. Microbial Toxicity of Isopropyl Myristate Used for Sterility Testing of Petrolatum-Based Ophthalmic Ointments

    PubMed Central

    Tsuji, Kiyoshi; Robertson, John H.

    1973-01-01

    The toxicity of isopropyl myristate (IPM) to microorganisms varies from lot to lot and between manufacturers. The toxicity is not directly proportional to the number and level of IPM homologues present nor to the small quantities of fatty acids, alcohols, aldehydes, or ketones found in both filter- and heat-sterilized IPM. The toxicity of IPM, both filter- and heat-sterilized, has no correlation with the usual physical and chemical characteristics of IPM but shows excellent correlation (correlation coefficient, r = 0.88) with the pH of a water extract of IPM. The toxic compounds can be removed and the toxicity of both filter- and heat-sterilized IPM can be reduced by basic alumina treatment. These findings may indicate that trace amounts of acidic catalysts remaining after production of IPM are responsible for the toxic effect. PMID:4631433

  1. Microbial toxicity of isopropyl myristate used for sterility testing of petrolatum-based ophthalmic ointments.

    PubMed

    Tsuji, K; Robertson, J H

    1973-01-01

    The toxicity of isopropyl myristate (IPM) to microorganisms varies from lot to lot and between manufacturers. The toxicity is not directly proportional to the number and level of IPM homologues present nor to the small quantities of fatty acids, alcohols, aldehydes, or ketones found in both filter- and heat-sterilized IPM. The toxicity of IPM, both filter- and heat-sterilized, has no correlation with the usual physical and chemical characteristics of IPM but shows excellent correlation (correlation coefficient, r = 0.88) with the pH of a water extract of IPM. The toxic compounds can be removed and the toxicity of both filter- and heat-sterilized IPM can be reduced by basic alumina treatment. These findings may indicate that trace amounts of acidic catalysts remaining after production of IPM are responsible for the toxic effect.

  2. Phase behavior of the thermoresponsive polymer Poly(N-isopropyl acrylamide) at variable pressure

    NASA Astrophysics Data System (ADS)

    Schulte, Alfons; Claude, Kora-Lee; Pinzek, Simon; Müller-Buschbaum, Peter; Papadakis, Christine

    Stimuli-responsive such as Poly(N-isopropyl acrylamide) (PNIPAM) exhibit lower critical solution temperature (LCST) behaviour. At ambient pressure it is associated with the release of water and coil to globule transition of the polymer chains, leading to phase separation. Using turbidimetry we measure the P-T phase diagram over an extended range of pressure (0.1 - 400 MPa) and temperature (-10 - 40 oC). The phase boundary shows an elliptic profile, i.e. the cloud point temperature first increases and then decreases with pressure. This is reflected in the change in Gibbs free energy, isothermal compressibility, and isobaric heat capacity. The role of solvent-solvent interaction and addition of co-solvents is discussed.

  3. Demixing transition and molecular interactions in Poly(N-isopropyl acrylamide) solutions compared to its monomer

    NASA Astrophysics Data System (ADS)

    Futscher, Moritz; Philipp, Martine; Mueller-Buschbaum, Peter; Schulte, Alfons

    2015-03-01

    Temperature-sensitive hydrogels such as poly(N-isopropyl acrylamide) (PNIPAM) exhibit a coil to globule transition of the polymer chains with a lower critical solution temperature (LCST) near 305 K. The cooperative dehydration of bound water molecules upon heating plays a significant role. The hydrogen bonding with the the amide groups in the side chains has to be contrasted with the hydration interaction of the hydrophobic main chain hydro-carbons. Employing FTIR spectroscopy we probe molecular changes in the various chemical groups. PNIPAM and its monomer NIPAM are investigated at a concentration of 20% in aqueous solution. We observe a nearly discontinuous shift of the the peak frequencies and the intensities of vibrational bands (amides, CH) in PNIPAM, whereas in NIPAM there is a continuous linear shift with temperature. The results are discussed with respect to hydration changes in the amide group and cooperative interactions with bound water along the backbone chain.

  4. Impact of volume transition on the net charge of poly-N -isopropyl acrylamide microgels

    NASA Astrophysics Data System (ADS)

    Braibanti, M.; Haro-Pérez, C.; Quesada-Pérez, M.; Rojas-Ochoa, L. F.; Trappe, V.

    2016-09-01

    We explore the electrostatic properties of poly-N -isopropyl acrylamide microgels in dilute, quasi-de-ionized dispersions and show that the apparent net charge of these thermosensitive microgels is an increasing function of their size, the size being conveniently varied by temperature. Our experimental results obtained in a combination of light scattering, conductivity, and mobility experiments are consistent with those obtained in Poisson-Boltzmann cell model calculations, effectively indicating that upon shrinking the number of counterions entrapped within the microgels increases. Remarkably, this behavior shows that the electrostatic energy per particle remains constant upon swelling or deswelling the microgel, resulting in a square root dependence of the net charge on the particle radius.

  5. Synthesis of Isopropyl Ferulate Using Silica-Immobilized Lipase in an Organic Medium

    PubMed Central

    Kumar, Ashok; Kanwar, Shamsher Singh

    2011-01-01

    Immobilization of lipases has proved to be a useful technique for improving an enzyme's activity in organic solvents. In the present study, the performance of a silica-immobilized lipase was evaluated for the synthesis of isopropyl ferulate in DMSO. The biocatalyst was cross-linked onto the matrix with 1% glutaraldehyde. The effects of various parameters, molar ratio of ferulic acid to isopropyl alcohol (25 mM : 100 mM), concentration of biocatalyst (2.5–20 mg/mL), molecular sieves (25–250 mg/mL), and various salt ions, were studied consecutively as a function of percent esterification. Immobilized lipase at 25 mg/mL showed maximum esterification (~84%) of ferulic acid and isopropanol at a molar ratio of 25 mM : 100 mM, respectively, in DMSO at 45°C in 3 h under shaking (150 rpm). To overcome the inhibitory effect of water (a byproduct) if any, in the reaction mixture, molecular sieves (3 Å × 1.5 mm; 100 mg/mL) were added to the reaction mixture to promote the forward reaction. Salt ions like Ca2+, Cd2+, and Fe2+ enhanced the activity of immobilized biocatalyst while a few ions like Co2+, Zn2+, Mg2+, Mn2+, Al3+, and Na+ had mild inhibitory effect. Approximately, one third of total decrease in the esterification efficacy was observed after the 5th repetitive cycle of esterification. PMID:21603272

  6. Purification of aqueous cellulose ethers

    SciTech Connect

    Bartscherer, K.A.; de Pablo, J.J.; Bonnin, M.C.; Prausnitz, J.M.

    1990-07-01

    Manufacture of cellulose ethers usually involves high amounts of salt by-products. For application of the product, salt must be removed. In this work, we have studied the injection of high-pressure CO{sub 2} into an aqueous polymer-salt solution; we find that upon addition of isopropanol in addition to CO{sub 2}, the solution separates into two phases. One phase is rich in polymer and water, and the other phase contains mostly isopropanol, water and CO{sub 2}. The salt distributes between the two phases, thereby offering interesting possibilities for development of a new purification process for water-soluble polymers. This work presents experimental phase-equilibrium data for hydroxyethyl cellulose and sodium carboxymethyl cellulose with sodium acetate and potassium sulfate, respectively, in the region 40{degree}C and 30 to 80 bar. Based on these data, we suggest a process for the manufacture and purification of water-soluble cellulose ethers. 15 refs., 14 figs., 9 tabs.

  7. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  8. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  9. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  10. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  11. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  12. An expedient synthesis of linden ether.

    PubMed

    Serra, Stefano; Cominetti, Alessandra A

    2014-03-01

    We here describe a comprehensive study on the preparation of the intensive flavor 3,9-epoxy-p-mentha-1,4(8)-diene (1). Key steps of the presented synthesis are the selective addition of MeLi to the keto-ester 7, the regioselective cyclization of the obtained triol to give the ethers 4 and 8 and the selective dehydration of ether 4 through the use of POCI3 and pyridine. It is worth noting that the presented synthesis represents the first expedient and reliable entry to ether 1. Being present in linden honey, 1 is also known as linden ether and it has been regarded as a potential marker for the authentication of the linden honey origin. Therefore, ether 1 can be used as a useful reference standard for the analysis of the natural flavors, as we demonstrated by means of its identification in a sample ofunifloral linden honey.

  13. The Activation Effects of Low Level Isopropyl Alcohol Exposure on Arterial Blood Pressures Are Associated with Decreased 5-Hydroxyindole Acetic Acid in Urine

    PubMed Central

    Zhao, Zhiqiang; Liu, Xinxia; Xing, Xiumei; Lu, Yao; Sun, Yi; Ou, Xiaoyan; Su, Xiaolin; Jiang, Jun; Yang, Yarui; Chen, Jingli; Shen, Biling; He, Yun

    2016-01-01

    Purposes The objectives of this paper are to study the impact of low level isopropyl alcohol exposure on blood pressure and to explore its potential mechanism. Methods This cross-sectional study was based on a prospective occupational cohort in south China, which focusing on occupational risk factors related cardiovascular health problems. A total of 283 participants (200 low isopropyl alcohol exposed workers and 83 controls) was finally enrolled in this study. Linear regression models were used to analyze the relationship between arterial blood pressures and low level isopropyl alcohol exposure. We used mediation method to explore possible mediated roles of neurogenic factors. Results Systolic blood pressure (SBP, 123±10 vs. 118±11), diastolic blood pressure (DBP, 79±7 vs. 74±7) and mean blood pressure (MBP, 93±8 vs. 89±9) were different between the exposed group and the control group (p < 0.01). After adjusting for covariates, the difference was still significant. Besides, isopropyl alcohol and smoking had an interactive effect on DBP and MBP (p < 0.05). Furthermore, we observed a mediated effect of 5-hydroxyindole acetic acid (5-HIAA) on isopropyl alcohol exposure induced arterial blood pressure increase, which accounted for about 25%. Conclusions Our results suggest that low level isopropyl alcohol exposure is a potential risk factor for the increased arterial blood pressure and 5-HIAA partly mediates the association between low level isopropyl alcohol exposure and arterial blood pressures. PMID:27622502

  14. Cutaneous metabolism of glycol ethers.

    PubMed

    Lockley, David J; Howes, Douglas; Williams, Faith M

    2005-03-01

    The toxicity of glycol ethers is associated with their oxidation to the corresponding aldehyde and alkoxyacetic acid by cytosolic alcohol dehydrogenase (ADH; EC 1.1.1.1.) and aldehyde dehydrogenase (ALDH; 1.2.1.3). Dermal exposure to these compounds can result in localised or systemic toxicity including skin sensitisation and irritancy, reproductive, developmental and haemotological effects. It has previously been shown that skin has the capacity for local metabolism of applied chemicals. Therefore, there is a requirement to consider metabolism during dermal absorption of these compounds in risk assessment for humans. Cytosolic fractions were prepared from rat liver, and whole and dermatomed skin by differential centrifugation. Rat skin cytosolic fractions were also prepared following multiple dermal exposure to dexamethasone, ethanol or 2-butoxyethanol (2-BE). The rate of ethanol, 2-ethoxyethanol (2-EE), ethylene glycol, 2-phenoxyethanol (2-PE) and 2-BE conversion to alkoxyacetic acid by ADH/ALDH in these fractions was continuously monitored by UV spectrophotometry via the conversion of NAD+ to NADH at 340 nm. Rates of ADH oxidation by rat liver cytosol were greatest for ethanol followed by 2-EE >ethylene glycol >2-PE >2-BE. However, the order of metabolism changed to 2-BE >2-PE >ethylene glycol >2-EE >ethanol using whole and dermatomed rat skin cytosolic fractions, with approximately twice the specific activity in dermatomed skin cytosol relative to whole rat skin. This suggests that ADH and ALDH are localised in the epidermis that constitutes more of the protein in dermatomed skin than whole skin cytosol. Inhibition of ADH oxidation in rat liver cytosol by pyrazole was greatest for ethanol followed by 2-EE >ethylene glycol >2-PE >2-BE, but it only inhibited ethanol metabolism by 40% in skin cytosol. Disulfiram completely inhibited alcohol and glycol ether metabolism in the liver and skin cytosolic fractions. Although ADH1, ADH2 and ADH3 are expressed at the

  15. Synthesis and pharmacological profile of bicyclo[2.2.2]octane derivatives: N-(1-aryl-4-piperazinyl-butyl) derivatives of 7-isopropyl-6-methyl- and 1-isopropyl-4-methylbicyclo[2.2.2]oct-5-ene-2,3-dicarboxyimide.

    PubMed

    Zawadowski, T; Skowron, A A; Suski, S; Rump, S; Jakowicz, I

    1995-01-01

    The new class of compounds characterized by anxiolytic or antidepressive properties, including a number of N-(1-aryl-4-piperazinylbutyl) derivatives of the two isomers: 7-isopropyl-6-methyl- and 1-isopropyl-4-methylbicyclo [2.2.2]oct-5-ene-2,3-dicarboxyimide was synthesized. Two compounds were selected for further pharmacological study.

  16. [Hydrotris(3-isopropyl-5-methylpyazolyl)borato]-iodocobalt(II): Unusual purification by {open_quotes}inverse recrystallization{close_quotes}

    SciTech Connect

    Reinaud, O.M.; Rheingold, A.L.; Theopold, K.H.

    1994-05-11

    In the search for homogeneous oxidation catalysts, the authors are investigating sterically hindered tris(pyrazolyl) borate complexes. For example, hydrotris(3-tert-butyl-5-methylpyrazolyl)borate (Tp{prime}) stabilizes the unusual side-on bonded superoxo-cobalt complex Tp{prime}Co{sup II}(O{sub 2}). During study of this complex there arose the need to prepare an analogous molecule with isopropyl groups in place of the tert-butyl substituents of the pyrazolyl rings. As a starting material for this chemistry, the authors prepared and structurally characterized Tp{double_prime}Co{sup II}I (Tp{double_prime} = hydrotris(3-isopropyl-5-methylpyrazoly)borate). The separation of the latter from its regioisomers takes advantage of a rather unusual solubility effect, termed {open_quotes}inverse recrystallization{close_quotes}. The potential utility of this phenomenon in related systems prompted this note.

  17. Antimicrobial efficacy of a novel eucalyptus oil, chlorhexidine digluconate and isopropyl alcohol biocide formulation.

    PubMed

    Hendry, Emma; Conway, Barbara; Worthington, Tony

    2012-01-01

    Effective surface disinfection is a fundamental infection control strategy within healthcare. This study assessed the antimicrobial efficacy of novel biocide formulations comprising 5% and 2% eucalyptus oil (EO) combined with 2% chlorhexidine digluconate (CHG) and 70% isopropyl alcohol (IPA) contained within a wipe. The efficacy of this novel antimicrobial formulation to remove and eliminate methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Candida albicans from steel surfaces was investigated. Adpression studies of pre-contaminated wipes were also utilised to assess their potential to induce cross-contamination between hard surfaces. Furthermore, the bactericidal nature of the EO-formulation was established in addition to time-kill. The EO-containing formulations demonstrated bactericidal antimicrobial efficacy against all microorganisms and did not induce surface cross-contamination. There was no significant difference (p < 0.05) between the 5% and 2% EO formulations in their ability to remove microorganisms from steel surfaces, however both significantly (p < 0.05) removed more than the control formulations. Microbial biofilms were eliminated within 10 min (p < 0.05) when exposed to the EO formulations. Our novel EO-formulation demonstrated rapid antimicrobial efficacy for potential disinfection and elimination of microbial biofilms from hard surfaces and may therefore be a useful adjunct to current infection control strategies currently employed within healthcare facilities.

  18. Antimicrobial Efficacy of a Novel Eucalyptus Oil, Chlorhexidine Digluconate and Isopropyl Alcohol Biocide Formulation

    PubMed Central

    Hendry, Emma; Conway, Barbara; Worthington, Tony

    2012-01-01

    Effective surface disinfection is a fundamental infection control strategy within healthcare. This study assessed the antimicrobial efficacy of novel biocide formulations comprising 5% and 2% eucalyptus oil (EO) combined with 2% chlorhexidine digluconate (CHG) and 70% isopropyl alcohol (IPA) contained within a wipe. The efficacy of this novel antimicrobial formulation to remove and eliminate methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Candida albicans from steel surfaces was investigated. Adpression studies of pre-contaminated wipes were also utilised to assess their potential to induce cross-contamination between hard surfaces. Furthermore, the bactericidal nature of the EO-formulation was established in addition to time-kill. The EO-containing formulations demonstrated bactericidal antimicrobial efficacy against all microorganisms and did not induce surface cross-contamination. There was no significant difference (p < 0.05) between the 5% and 2% EO formulations in their ability to remove microorganisms from steel surfaces, however both significantly (p < 0.05) removed more than the control formulations. Microbial biofilms were eliminated within 10 min (p < 0.05) when exposed to the EO formulations. Our novel EO-formulation demonstrated rapid antimicrobial efficacy for potential disinfection and elimination of microbial biofilms from hard surfaces and may therefore be a useful adjunct to current infection control strategies currently employed within healthcare facilities. PMID:23203047

  19. Recovery of isopropyl alcohol from waste solvent of a semiconductor plant.

    PubMed

    Lin, Sheng H; Wang, Chuen S

    2004-01-30

    An important waste solvent generated in the semiconductor manufacturing process was characterized by high isopropyl alcohol (IPA) concentration over 65%, other organic pollutants and strong color. Because of these characteristics, IPA recovery was deemed as a logic choice for tackling this waste solvent. In the present work, an integrated method consisting of air stripping in conjunction with condensation and packed activated carbon fiber (ACF) adsorption for dealing with this waste solvent. The air stripping with proper stripping temperature control was employed to remove IPA from the waste solvent and the IPA vapor in the gas mixture was condensed out in a side condenser. The residual IPA remaining in the gas mixture exiting the side condenser was efficiently removed in a packed ACF column. The air stripping with condensation was able to recover up to 93% of total IPA in the initial waste solvent. The residual IPA in the gas mixture, representing less than 3% of the initial IPA, was efficiently captured in the packed ACF column. Experimental tests were conducted to examine the performances of each unit and to identify the optimum operating conditions. Theoretical modeling of the experimental IPA breakthrough curves was also undertaken using a macroscopic model. The verified breakthrough model significantly facilitates the adsorption column design. The recovered IPA was found to be of high purity and could be considered for reuse.

  20. Quantifying local cerebral blood flow by N-isopropyl-p-(123I)iodoamphetamine (IMP) tomography

    SciTech Connect

    Kuhl, D.E.; Barrio, J.R.; Huang, S.C.; Selin, C.; Ackermann, R.F.; Lear, J.L.; Wu, J.L.; Lin, T.H.; Phelps, M.E.

    1982-03-01

    A model was validated wherein local cerebral blood flow (LCBF) in humans was quantified by single-photon emission computed tomography (SPECT) with intravenously injected N-isopropyl-p-(123I)iodoamphetamine (IMP) combined with a modification of the classic method of arterial input sampling. After intravenous injection of IMP in rat, autoradiograms of the brain showed activity distributions in the pattern of LCBF. IMP was nearly completely removed on first pass through monkey brain after intracarotid injection (CBF.33 ml/100 g/min) and washed out with a half-time of approximately 1 hr. When the modified method of arterial input and tissue-sample counting applied to dog brain, there was good correspondence between LCBF based on IMP and on that by microsphere injection over a wide flow range. In applying the method to human subjects using SPECT, whole-brain CBF measured 47.2 +/- 5.4 ml/100 g/min (mean +/- s.d., N.5), stable gray-white distinction persisted for over 1 hr, and the half-time for brain washout was approximately 1 hr. Perfusion deficits in patients were clearly demonstrated and quantified, comparing well with results now available from positron ECT.

  1. Fingerprinting of hydroxyl radical-attacked polysaccharides by N-isopropyl-2-aminoacridone labelling.

    PubMed

    Vreeburg, Robert A M; Airianah, Othman B; Fry, Stephen C

    2014-10-15

    Hydroxyl radicals (•OH) cause non-enzymic scission of polysaccharides in diverse biological systems. Such reactions can be detrimental (e.g. causing rheumatic and arthritic diseases in mammals) or beneficial (e.g. promoting the softening of ripening fruit, and biomass saccharification). Here we present a method for documenting •OH action, based on fluorescent labelling of the oxo groups that are introduced as glycosulose residues when •OH attacks polysaccharides. The method was tested on several polysaccharides, especially pectin, after treatment with Fenton reagents. 2-Aminoacridone plus cyanoborohydride reductively aminated the oxo groups in treated polysaccharides; the product was then reacted with acetone plus cyanoborohydride, forming a stable tertiary amine with the carbohydrate linked to N-isopropyl-2-aminoacridone (pAMAC). Digestion of labelled pectin with 'Driselase' yielded several fluorescent products which on electrophoresis and HPLC provided a useful 'fingerprint' indicating •OH attack. The most diagnostic product was a disaccharide conjugate of the type pAMAC·UA-GalA (UA=unspecified uronic acid), whose UA-GalA bond was Driselase-resistant (product 2A). 2A was clearly distinguishable from GalA-GalA-pAMAC (disaccharide labelled at its reducing end), which was digestible to GalA-pAMAC. The methodology is applicable, with appropriate enzymes in place of Driselase, for detecting natural and artificial •OH attack in diverse plant, animal and microbial polysaccharides.

  2. Synthesis and fabrication of a degradable poly(N-isopropyl acrylamide) scaffold for tissue engineering applications

    PubMed Central

    Galperin, Anna; Long, Thomas J.; Garty, Shai; Ratner, Buddy D.

    2013-01-01

    Biodegradable poly(N-isopropyl acrylamide) (poly-NIPAM) hydrogels with controlled molecular weight of the parent polymer and its degradation products were synthesized by atom transfer radical polymerization in the presence of a polycaprolactone-based di-chlorinated macroinitiator and polycaprolactone dimethacrylate. The phase transition temperature, swelling, hydrolytic degradability, and mechanical properties at 25 and 37°C were explored. A cytocompatibility study showed good NIH3T3 cell response over 5 days culture on the surface of the hydrogels, demonstrated by a consistent increase in cell proliferation detected by an Alamar Blue assay. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazo-lium bromide] results suggested that the hydrogels and their degradation products in the concentration range of 1–25 mg/ mL were not cytotoxic to NIH3T3 cells. A sphere-templating technique was utilized to fabricate biodegradable polyNIPAM scaffolds with monodisperse, pore size. Scaffolds with pore diameter of 48 ± 6 μm were loaded with A-10 smooth muscle cells and then warmed to 37°C entrapping cells in pores approximately 40 μm in diameter, a size we have found to be optimal for angiogenesis and biointegration. Due to their degradable nature, tunable molecular weight, highly interconnected morphology, thermally controlled monodisperse pore size, and temperature-induced volume expansion–contraction, the polyNIPAM-based scaffolds developed in this work will be valuable in tissue engineering. PMID:22961921

  3. Cleanroom airborne particulate limits and 70% isopropyl alcohol: a lingering problem for pharmaceutical manufacturing?

    PubMed

    Eaton, Tim

    2009-01-01

    Seventy percent isopropyl alcohol (70% IPA) in water for injection is extensively utilised within pharmaceutical cleanrooms for glove and surface disinfection. When supplied in pressurised containers and delivered as an aerosol, it has been demonstrated that large quantities of 70% IPA particles are generated that remain airborne for substantial periods of time. Within non-unidirectional airflow cleanroom areas, such particles are likely to be recorded by the particle monitoring system. Consequently, the derived operational limits for particles will almost certainly be at "artificially high" levels and any particle generating activities with contamination potential may be masked. These high particle levels may not comply with the requirements of Annex 1 of the European Unions Guide to Good Manufacturing Practices (EU GGMP) and the United States Food and Drug Administration (FDA) Aseptic Processing Guideline. This is the case predominantly for the larger particles (> or =5 microm), the monitoring of which is exclusively required by the Annex 1 guide. However, by using canisters that deliver the 70% IPA as a stream, large quantities of particles are not generated and more meaningful and compliant operational levels can be obtained. Additionally, the EU GGMP's Annex 1 continuing requirement to monitor particles > or =5 microm appears to have little value or scientific justification and restricts further harmonisation of the European guide with the US FDA Aseptic Processing Guideline.

  4. Detection thresholds for 2-isopropyl-3-methoxypyrazine in Concord and Niagara grape juice.

    PubMed

    Pickering, G J; Karthik, A; Inglis, D; Sears, M; Ker, K

    2008-08-01

    2-isopropyl-3-methoxypyrazine (IPMP) is the compound responsible for the off-flavor known as ladybug taint, which occurs when Harmnonia axyridis beetles become incorporated with the grapes during juice processing. It is also an important grape-derived component of juice flavor in some varieties. The main objective of this study was to determine the orthonasal (ON) and retronasal (RN) detection thresholds for IPMP in juice. The ASTM E679 ascending forced choice method of limits was used to determine detection thresholds for 26 individuals in Concord and Niagara juices. Group best estimate thresholds (BETs) averaged 0.93 ng/L and were 50% and 21% higher in Concord than in Niagara juices for ON and RN evaluation, respectively. Group BETs for IPMP (ng/L) for Concord were ON: 1.11; RN: 1.02 and for Niagara were ON: 0.74; RN: 0.84. Variation in individual detection thresholds was observed, although familiarity with ladybug taint was not associated with individual threshold values. We conclude that humans are very sensitive to IPMP in juice, and that detection thresholds are more strongly influenced by grape variety than evaluation mode. These results may assist juice producers in establishing tolerance levels for IPMP in juice affected by ladybug taint or derived from grapes of suboptimal ripeness. PMID:19241569

  5. Determination of ortho- and retronasal detection thresholds for 2-isopropyl-3-methoxypyrazine in wine.

    PubMed

    Pickering, G J; Karthik, A; Inglis, D; Sears, M; Ker, K

    2007-09-01

    2-Isopropyl-3-methoxypyrazine (IPMP) is a grape-derived component of wine flavor in some wine varieties as well as the causal compound of the off-flavor known as ladybug taint (LBT), which occurs when Harmonia axyridis beetles are incorporated with the grapes during juice and wine processing. The main objective of this study was to obtain robust estimates of the orthonasal (ON) and retronasal (RN) detection thresholds (DTs) for IPMP in wines of differing styles. The ASTM E679 ascending forced choice method of limits was used to determine DTs for 47 individuals in 3 different wines--Chardonnay, Gewürztraminer, and a red wine blend of Baco Noir and Marechel Foch. The group best estimate thresholds (BETs) obtained for IPMP (ng/L) were Chardonnay, ON: 0.32; Gewürztraminer, ON: 1.56, RN: 1.15, and red wine blend, ON: 1.03, RN: 2.29. A large variation in individual DTs was observed. Familiarity with LBT was inversely correlated with DTs for Gewürztraminer, and no difference in thresholds was observed between winemakers and nonwinemakers. We conclude that the human DT for IPMP is extremely low and influenced significantly by wine style and evaluation mode. We recommend against the reporting of single-threshold values for wine flavor compounds, and encourage the determination of consumer rejection thresholds for IPMP in wine. PMID:17995659

  6. Hugoniot Information for Bromonitromethane, Isopropyl Nitrate, and 90 wt% H_2O_2

    NASA Astrophysics Data System (ADS)

    Sheffield, Stephen A.; Davis, Lloyd; Engelke, Ray

    1998-03-01

    Hugoniot curves and related information are reported for three liquid explosives: bromonitromethane (BrNM), isopropyl nitrate (IPN), and 90/10 wt% hydrogen peroxide/water (H_2O_2). Hugoniot curves were determined using the measured sound speeds and the universal liquid Hugoniot empirical form(Woolfolk, R. W.; Cowperthwaite, M.; Shaw, R. Thermochimica Acta,) 1973, 5, 409-414. which only requires the initial sound speed as a parameter. We measured sound speeds for these liquids. In addition, gas gun experiments were conducted to determine experimental Hugoniot states for BrNM and IPN. Magnetic gauges were used to measure the input particle velocity and to track the shock front (a shock velocity measurement), providing the necessary information to determine a Hugoniot state. These measured states were compared to those predicted using the universal liquid Hugoniot and agreement was found to be very good. Using the calculated Hugoniot curves and the detonation velocities for IPN and H_2O_2, von Neumann spike detonation conditions were estimated and compared to nitromethane (NM). BrNM was also found to be more sensitive to shock initiation than neat NM.

  7. SPECT with N-isopropyl-p iodoamphetamine in occlusive cerebrovascular diseases.

    PubMed

    Higa, T; Tanaka, T; Ikekubo, K; Komatsu, T; Torizuka, K

    1986-12-01

    The role of SPECT imaging with N-isopropyl-p iodoamphetamine (I-123 IMP) in the detection of angiographically documented occlusive cerebrovascular diseases was evaluated in 24 patients, and the results of regional cerebral blood flow (rCBF) were compared with x-ray CT. Twelve patients had internal carotid occlusion, ten had intracranial occlusion beyond the circle of Willis, one had common carotid occlusion, and one had basilar artery occlusion. SPECT images were obtained with a gamma camera, which was rotated 360 degrees around the patient's head 30 minutes after an intravenous injection of 3 mCi of I-123 IMP. CT images in the transverse plane were obtained, and the regions of reduced attenuation were identified for comparison of topographic extension of the lesion with the regions of decreased rCBF seen on SPECT. In six cases, the lesions seen on the SPECT images were distinctly more extensive than those seen on CT. In the remaining 18 cases, the extent of the lesion was identical on both CT and SPECT images. Radiochemical and radionuclide impurities, the distance of the detector from the head, and the nature of the collimator affected the SPECT results. I-123 IMP SPECT imaging complements CT findings in detecting the ischemic zones beyond the regions identified on CT images, and may have a major rule in the management of patients with occlusive cerebrovascular diseases.

  8. Enzymatic Synthesis of Isopropyl Acetate by Immobilized Bacillus cereus Lipase in Organic Medium

    PubMed Central

    Verma, Madan Lal; Azmi, Wamik; Kanwar, Shamsher Singh

    2011-01-01

    Selective production of fragrance fatty acid ester from isopropanol and acetic acid has been achieved using silica-immobilized lipase of Bacillus cereus MTCC 8372. A purified thermoalkalophilic extracellular lipase was immobilized by adsorption onto the silica. The effects of various parameters like molar ratio of substrates (isopropanol and acetic acid; 25 to 100 mM), concentration of biocatalyst (25–125 mg/mL), reaction time, reaction temperature, organic solvents, molecular sieves, and initial water activity were studied for optimal ester synthesis. Under optimized conditions, 66.0 mM of isopropyl acetate was produced when isopropanol and acetic acid were used at 100 mM: 75 mM in 9 h at 55°C in n-heptane under continuous shaking (160 rpm) using bound lipase (25 mg). Addition of molecular sieves (3 Å × 1.5 mm) resulted in a marked increase in ester synthesis (73.0 mM). Ester synthesis was enhanced by water activity associated with pre-equilibrated saturated salt solution of LiCl. The immobilized lipase retained more than 50% of its activity after the 6th cycle of reuse. PMID:21603222

  9. Fingerprinting of hydroxyl radical-attacked polysaccharides by N-isopropyl-2-aminoacridone labelling

    PubMed Central

    Vreeburg, Robert A. M.; Airianah, Othman B.; Fry, Stephen C.

    2014-01-01

    Hydroxyl radicals (•OH) cause non-enzymic scission of polysaccharides in diverse biological systems. Such reactions can be detrimental (e.g. causing rheumatic and arthritic diseases in mammals) or beneficial (e.g. promoting the softening of ripening fruit, and biomass saccharification). Here we present a method for documenting •OH action, based on fluorescent labelling of the oxo groups that are introduced as glycosulose residues when •OH attacks polysaccharides. The method was tested on several polysaccharides, especially pectin, after treatment with Fenton reagents. 2-Aminoacridone plus cyanoborohydride reductively aminated the oxo groups in treated polysaccharides; the product was then reacted with acetone plus cyanoborohydride, forming a stable tertiary amine with the carbohydrate linked to N-isopropyl-2-aminoacridone (pAMAC). Digestion of labelled pectin with ‘Driselase’ yielded several fluorescent products which on electrophoresis and HPLC provided a useful ‘fingerprint’ indicating •OH attack. The most diagnostic product was a disaccharide conjugate of the type pAMAC·UA-GalA (UA=unspecified uronic acid), whose UA-GalA bond was Driselase-resistant (product 2A). 2A was clearly distinguishable from GalA-GalA–pAMAC (disaccharide labelled at its reducing end), which was digestible to GalA–pAMAC. The methodology is applicable, with appropriate enzymes in place of Driselase, for detecting natural and artificial •OH attack in diverse plant, animal and microbial polysaccharides. PMID:25072268

  10. Anxiolytic-like effect of Carvacrol (5-isopropyl-2-methylphenol) in mice: involvement with GABAergic transmission.

    PubMed

    Melo, Francisca Helvira Cavalcante; Venâncio, Edith Teles; de Sousa, Damião Pergentino; de França Fonteles, Marta Maria; de Vasconcelos, Silvânia Maria Mendes; Viana, Glauce Socorro Barros; de Sousa, Francisca Cléa Florenço

    2010-08-01

    Carvacrol (5-isopropyl-2-methylphenol) is a monoterpenic phenol present in the essencial oil of many plants. It is the major component of the essential oil fraction of oregano and thyme. This work presents the behavioral effects of carvacrol in animal models of elevated plus maze (EPM), open field, Rotarod and barbiturate-induced sleeping time tests in mice. Carvacrol (CVC) was administered orally, in male mice, at single doses of 12.5; 25 and 50 mg/kg while diazepam 1 or 2 mg/kg was used as standard drug and flumazenil (2.5 mg/kg) was used to elucidate the possible anxiolytic mechanism of CVC on the plus maze test. The results showed that CVC, at three doses, had no effect on the spontaneous motor activity in the Rotarod test nor in the number of squares crossed in the open-field test. However, CVC decreased the number of groomings in the open-field test. In the plus maze test, CVC, at three doses significantly increased all the observed parameters in the EPM test and flumazenil was able to reverse the effects of diazepam and CVC. Therefore, CVC did not alter the sleep latency and sleeping time in the barbiturate-induced sleeping time test. These results show that CVC presents anxiolytic effects in the plus maze test which are not influenced by the locomotor activity in the open-field test. PMID:19909350

  11. Combustion of isopropyl alcohol using a green manufactured CuFe2O4.

    PubMed

    Tu, Yao-Jen; Chang, Chien-Kuei; You, Chen-Feng

    2012-08-30

    A green method for manufacturing CuFe(2)O(4) from industrial Cu sludge was successfully developed by a combination of acid leaching, chemical exchange and ferrite process. The CuFe(2)O(4) was applied for combustion of volatile organic compounds (VOCs) derived from isopropyl alcohol (IPA). The results show that IPA was reacted to form intermediate acetone and CO(2) at the temperature range of 110-170°C. When the temperature was increased to 180°C, IPA can be 100% converted into CO(2). The 96-h decay tests indicated that the catalyst has a good thermal stability and durability under the conditions of gas hourly space velocity 30,000 h(-1), oxygen content 21%, IPA inlet concentration 2000 ppm, and reaction temperature 180°C. The results demonstrate great potential that our manufactured CuFe(2)O(4) catalyst can be used in combustion IPA streams to eliminate the emission of IPA. PMID:22727486

  12. Combustion of isopropyl alcohol using a green manufactured CuFe2O4.

    PubMed

    Tu, Yao-Jen; Chang, Chien-Kuei; You, Chen-Feng

    2012-08-30

    A green method for manufacturing CuFe(2)O(4) from industrial Cu sludge was successfully developed by a combination of acid leaching, chemical exchange and ferrite process. The CuFe(2)O(4) was applied for combustion of volatile organic compounds (VOCs) derived from isopropyl alcohol (IPA). The results show that IPA was reacted to form intermediate acetone and CO(2) at the temperature range of 110-170°C. When the temperature was increased to 180°C, IPA can be 100% converted into CO(2). The 96-h decay tests indicated that the catalyst has a good thermal stability and durability under the conditions of gas hourly space velocity 30,000 h(-1), oxygen content 21%, IPA inlet concentration 2000 ppm, and reaction temperature 180°C. The results demonstrate great potential that our manufactured CuFe(2)O(4) catalyst can be used in combustion IPA streams to eliminate the emission of IPA.

  13. Recovery of isopropyl alcohol from waste solvent of a semiconductor plant.

    PubMed

    Lin, Sheng H; Wang, Chuen S

    2004-01-30

    An important waste solvent generated in the semiconductor manufacturing process was characterized by high isopropyl alcohol (IPA) concentration over 65%, other organic pollutants and strong color. Because of these characteristics, IPA recovery was deemed as a logic choice for tackling this waste solvent. In the present work, an integrated method consisting of air stripping in conjunction with condensation and packed activated carbon fiber (ACF) adsorption for dealing with this waste solvent. The air stripping with proper stripping temperature control was employed to remove IPA from the waste solvent and the IPA vapor in the gas mixture was condensed out in a side condenser. The residual IPA remaining in the gas mixture exiting the side condenser was efficiently removed in a packed ACF column. The air stripping with condensation was able to recover up to 93% of total IPA in the initial waste solvent. The residual IPA in the gas mixture, representing less than 3% of the initial IPA, was efficiently captured in the packed ACF column. Experimental tests were conducted to examine the performances of each unit and to identify the optimum operating conditions. Theoretical modeling of the experimental IPA breakthrough curves was also undertaken using a macroscopic model. The verified breakthrough model significantly facilitates the adsorption column design. The recovered IPA was found to be of high purity and could be considered for reuse. PMID:15177106

  14. Superparamagnetic Fe3O4/Poly(N-isopropyl acrylamide) Nanocomposites Synthesized in Inverse Miniemulsions: Magnetic and Particle Properties.

    PubMed

    Cui, Qinmin; Zhu, Shudi; Yan, Yingjie; Ye, Quanlin; Ziener, Ulrich; Cao, Zhihai

    2015-06-01

    In the present study, superparamagnetic Fe3O4/poly(N-isopropyl acrylamide) nanocomposites were synthesized by one-step inverse miniemulsion copolymerization of N-isopropyl acrylamide and N,N'-methylene diacrylamide. The loading of Fe3O4 nanoparticles in the nanocomposites was 27 wt%, and the saturation moment of the nanocomposites was 12.4 emu x g(-1). Fe3O4 nanoparticles were prepared through a coprecipitation method. The amount of stabilizer (poly(acrylic acid)) significantly influenced the size and size distribution of the Fe3O4 nanoparticles, and, therefore, their magnetic properties. Superparamagnetism of the Fe3O4 nanoparticles was preserved in the nanocomposites. The effects of synthetic parameters on the particle properties, namely surfactant loading, concentration of ferrofluid, type of lipophobe and initiator, and amount of cross-linker were investigated. Nanocomposites of Fe3O4/poly(N-isopropyl acrylamide) displayed a guava-like morphology, which they could retain after being redispersed in polar solvents. PMID:26369088

  15. Phenylethynl-terminated poly(arylene ethers)

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor); Bryant, Robert G. (Inventor); Hergenrother, Paul M. (Inventor)

    1993-01-01

    Phenylethynyl-terminated poly(arylene ethers) are prepared in a wide range of molecular weights by adjusting monomer ratio and adding an appropriate amount of 4-fluoro- 4'-phenylethynyl benzophenone during polymer synthesis. The resulting phenylethynyl-terminated poly(arylene ethers) react and crosslink upon curing for one hour at 350 C to provide materials with improved solvent resistance, higher modulus, and better high temperature properties than the linear, uncrosslinked polymers.

  16. Stereoselective analysis of herbicides by capillary electrophoresis using sulfobutyl ether beta-cyclodextrin as chiral selector.

    PubMed

    Desiderio, C; Polcaro, C M; Fanali, S

    1997-02-01

    Capillary zone electrophoresis has been used for the enantiomeric separation of several herbicides. Different beta-cyclodextrin (CD) derivatives have been investigated for chiral separations and among them the negatively charged sulfobutyl ether beta-cyclodextrin (SBE-beta-CD) proved to be effective for the stereo-selective resolutions of the investigated herbicides. The effect of CD concentration, buffer pH and organic modifier on effective mobilities, resolution and selectivity of the analytes have been studied. Addition of SBE-beta-CD (5-50 mg/mL) to the buffer at pH 9 resulted in a general increase of migration times as well as resolution. A CD concentration as low as 5 mg/mL was effective to completely resolve napropamide and ethofumesate enantiomers. Buffer solutions containing 40 mg/mL of SBE-beta-CD were chosen to study the effect of buffer pH (7, 8, and 9) on chiral separation of the herbicides. No great differences in resolution and effective mobilities have been found in the pH 7-9 range. The addition of different organic modifiers to the background electrolyte at pH 9, containing 20 mg/mL of SBE-beta-CD, showed different effects. Methanol was the most effective in improving resolution but in some cases total loss in enantiomeric separation was observed. The qualitative analysis of an enantiomerically pure herbicide (flamprop isopropyl) commercial preparation is also shown.

  17. Stereoselective analysis of herbicides by capillary electrophoresis using sulfobutyl ether beta-cyclodextrin as chiral selector.

    PubMed

    Desiderio, C; Polcaro, C M; Fanali, S

    1997-02-01

    Capillary zone electrophoresis has been used for the enantiomeric separation of several herbicides. Different beta-cyclodextrin (CD) derivatives have been investigated for chiral separations and among them the negatively charged sulfobutyl ether beta-cyclodextrin (SBE-beta-CD) proved to be effective for the stereo-selective resolutions of the investigated herbicides. The effect of CD concentration, buffer pH and organic modifier on effective mobilities, resolution and selectivity of the analytes have been studied. Addition of SBE-beta-CD (5-50 mg/mL) to the buffer at pH 9 resulted in a general increase of migration times as well as resolution. A CD concentration as low as 5 mg/mL was effective to completely resolve napropamide and ethofumesate enantiomers. Buffer solutions containing 40 mg/mL of SBE-beta-CD were chosen to study the effect of buffer pH (7, 8, and 9) on chiral separation of the herbicides. No great differences in resolution and effective mobilities have been found in the pH 7-9 range. The addition of different organic modifiers to the background electrolyte at pH 9, containing 20 mg/mL of SBE-beta-CD, showed different effects. Methanol was the most effective in improving resolution but in some cases total loss in enantiomeric separation was observed. The qualitative analysis of an enantiomerically pure herbicide (flamprop isopropyl) commercial preparation is also shown. PMID:9080130

  18. Conformations and Barriers to Methyl Group Internal Rotation in Two Asymmetric Ethers: Propyl Methyl Ether and Butyl Methyl Ether

    NASA Astrophysics Data System (ADS)

    Long, B. E.; Dechirico, F.; Cooke, S. A.

    2012-06-01

    The conformational preferences of the O-C-C-C unit are important in many biological systems with the unit generally preferring a gauche configuration compared to an anti configuration. Butyl methyl ether and propyl methyl ether provide very simple systems for this phenomenom to manifest. Pure rotational spectra of the title molecules have been recorded using chirped pulse Fourier transform microwave spectroscopy (CP-FTMW). In the case of butyl methyl ether, only one conformer has been observed. This conformer has torsional angles of COCC = 180°, OCCC = 62° and CCCC = 180° (anti-gauche-anti) and rotational constants of A = 10259.4591(33) MHz, B = 1445.6470(13) MHz, and C = 1356.2944(14) MHz. The rotational spectrum was doubled and has been analyzed to produce an effective barrier to methyl group internal rotation of 780(35) cm-1. A prior rotational spectroscopic study on propyl methyl ether had focused only on the high energy anti-anti conformer. We have analyzed spectra from the lowest energy anti-gauche conformer and the spectroscopic constants will be presented. A summary of the differences in conformational energies and methyl group internal rotation barriers for the class of aliphatic asymmetric ethers will be presented. K. N. Houk, J. E. Eksterowicz, Y.-D. Wu, C. D. Fuglesang, D. B. Mitchell. J. Am. Chem. Soc. 115 (4170), 1993. Hiroshi Kato, Jun Nakagawa, Michiro Hayashi. J. Mol. Spectrosc. 80 (272), 1980.

  19. Gel-electrophoretic identification of hen brain neurotoxic esterase, labelled with tritiated di-isopropyl phosphorofluoridate.

    PubMed Central

    Williams, D G; Johnson, M K

    1981-01-01

    The particulate fraction from hen brain was labelled with [3H]di-isopropyl phosphorofluoridate (DiPF) and separated by polyacrylamide-gel electrophoresis. Four radioactive protein bands (1--4) of molecular weights 155000, 92000, 60000, and 30000 were resolved. Most of the labelling of bands 2, 3 and 4 was inhibited by preincubation with Paraoxon. The residue in band 4 was sensitive to pH 5.2. Successive treatments with Paraoxon and pH 5.2 resulted in the abolition of bands 3 and 4. Bands 1 and 2 contained one and two polypeptides respectively, whose labelling was sensitive to Mipafox, but one, in band 2, was sensitive to higher concentrations of Paraoxon. The concentrations of the other two polypeptides were 6.7 and 1.95 pmol of DiPF bound/g of brain in bands 1 and 2 respectively. Both were as sensitive to Mipafox as neurotoxic esterase and were also sensitive to phenyl benzylcarbamate. 4-Nitrophenyl di-n-pentylphosphinate given in vivo inhibited neurotoxic esterase and the labelling of the band-1 polypeptide by 82% and 84% respectively, but inhibited the labelling of the band 2 polypeptide by 51%. The phosphinate in vitro produced 98% inhibition of the labelling of the band-1 polypeptide, with only 26% inhibition of the band-2 polypeptide, under conditions sufficient to inhibit neurotoxic esterase totally. Both neurotoxic esterase and the band-1 polypeptide were found in the forebrain at 1.74-fold their concentration in the rest of the brain, whereas the band-2 polypeptide was uniformly distributed. The evidence indicates that the Mipafox-sensitive polypeptide in band 1 is the [3H]DiPF-labelled active-site subunit of neurotoxic esterase. The catalytic-centre activity of the enzyme for phenyl valerate hydrolysis was found to be 2.6 x 10(5) min-1. PMID:7340807

  20. Transdermal permeation of Kaempferia parviflora methoxyflavones from isopropyl myristate-based vehicles.

    PubMed

    Tuntiyasawasdikul, Sarunya; Limpongsa, Ekapol; Jaipakdee, Napaphak; Sripanidkulchai, Bungorn

    2014-08-01

    Kaempferia parviflora (K. parviflora) rhizomes have long been used in traditional folk medicines and as general health-promoting agents. Several biological activities of K. parviflora, especially its anti-inflammatory effect, are due to its major constituents, methoxyflavones. However, the oral bioavailability of these methoxyflavones has been shown to be low. The aim of this study was to investigate the permeation behaviors of K. parviflora methoxyflavones from isopropyl myristate (IPM)-based vehicles. We studied the effects of ethanol and propylene glycol (PG) as the hydrophilic, solvent-type vehicles as well as fatty acids as the permeation enhancers. A permeation experiment was performed in vitro, using side-by-side diffusion cells through the full thickness of pig ear skin. The solubility and permeation of methoxyflavones were able to be modified by choice and ratio of vehicles. The ethanol/IPM vehicle was shown to be more effective in enhancing the solubility and permeation of methoxyflavones when compared to the PG/IPM vehicle. Regarding an optimal balance between solubility or affinity to vehicle and skin to vehicle partition coefficient, the ethanol/IPM vehicle in the ratio of 1:9 maximized the flux. Among the investigated fatty acids, oleic acid showed the greatest enhancing effect on the permeation of methoxyflavones, indicating that saturated fatty acids are less effective than unsaturated fatty acids. Long chain fatty acids increased diffusion coefficient parameter and shortened the lag time. The number of carbon atoms and double bonds of fatty acids did not show direct relation to the profile of permeation of methoxyflavones.

  1. The Use of Liquid Isopropyl Alcohol and Hydrogen Peroxide Gas Plasma to Biologically Decontaminate Spacecraft Electronics

    NASA Technical Reports Server (NTRS)

    Bonner, J. K.; Tudryn, Carissa D.; Choi, Sun J.; Eulogio, Sebastian E.; Roberts, Timothy J.; Tudryn, Carissa D.

    2006-01-01

    Legitimate concern exists regarding sending spacecraft and their associated hardware to solar system bodies where they could possibly contaminate the body's surface with terrestrial microorganisms. The NASA approved guidelines for sterilization as set forth in NPG 8020.12C, which is consistent with the biological contamination control objectives of the Committee on Space Research (COSPAR), recommends subjecting the spacecraft and its associated hardware to dry heat-a dry heat regimen that could potentially employ a temperature of 110(deg)C for up to 200 hours. Such a temperature exposure could prove detrimental to the spacecraft electronics. The stimulated growth of intermetallic compounds (IMCs) in metallic interconnects and/or thermal degradation of organic materials composing much of the hardware could take place over a prolonged temperature regimen. Such detrimental phenomena would almost certainly compromise the integrity and reliability of the electronics. Investigation of sterilization procedures in the medical field suggests that hydrogen peroxide (H202) gas plasma (HPGP) technology can effectively function as an alternative to heat sterilization, especially for heat-sensitive items. Treatment with isopropyl alcohol (IPA) in liquid form prior to exposure of the hardware to HPGP should also prove beneficial. Although IPA is not a sterilant, it is frequently used as a disinfectant because of its bactericidal properties. The use of IPA in electronics cleaning is widely recognized and has been utilized for many years with no adverse affects reported. In addition, IPA is the principal ingredient of the test fluid used in ionic contamination testers to assess the amount of ionic contamination found on the surfaces of printed wiring assemblies. This paper will set forth experimental data confirming the feasibility of the IPA/H202 approach to reach acceptable microbial reduction (MR) levels of spacecraft electronic hardware. In addition, a proposed process flow in

  2. Sanitizing in Dry-Processing Environments Using Isopropyl Alcohol Quaternary Ammonium Formula.

    PubMed

    Kane, Deborah M; Getty, Kelly J K; Mayer, Brian; Mazzotta, Alejandro

    2016-01-01

    Dry-processing environments are particularly challenging to clean and sanitize because introduced water can favor growth and establishment of pathogenic microorganisms such as Salmonella. Our objective was to determine the efficacy of an isopropyl alcohol quaternary ammonium (IPAQuat) formula for eliminating potential Salmonella contamination on food contact surfaces. Clean stainless steel coupons and conveyor belt materials used in dry-processing environments were spot inoculated in the center of coupons (5 by 5 cm) with a six-serotype composite of Salmonella (approximately 10 log CFU/ml), subjected to IPAQuat sanitizer treatments with exposure times of 30 s, 1 min, or 5 min, and then swabbed for enumeration of posttreatment survivors. A subset of inoculated surfaces was soiled with a breadcrumb-flour blend and allowed to sit on the laboratory bench for a minimum of 16 h before sanitation. Pretreatment Salmonella populations (inoculated controls, 0 s treatment) were approximately 7.0 log CFU/25 cm(2), and posttreatment survivors were 1.31, 0.72, and < 0.7 (detection limit) log CFU/25 cm(2) after sanitizer exposure for 30 s, 1 min, or 5 min, respectively, for both clean (no added soil) and soiled surfaces. Treatment with the IPAQuat formula using 30-s sanitizer exposures resulted in 5.68-log reductions, whereas >6.0-log reductions were observed for sanitizer exposures of 1 and 5 min. Because water is not introduced into the processing environment with this approach, the IPAQuat formula could have sanitation applications in dry-processing environments to eliminate potential contamination from Salmonella on food contact surfaces. PMID:26735036

  3. 2-Ethyl-3-hy­droxy-1-isopropyl-4-pyridone

    PubMed Central

    Molokoane, Pule P.; Schutte, M.; Steyl, G.

    2012-01-01

    The title compound, C10H15NO2, crystallized with three mol­ecules in the asymmetric unit. These three mol­ecules are quite similar except for slight differences in the torsion angles of the substituents on the ring. The isopropyl C—C—N—C torsion angles (towards the carbon next to the ethyl bound carbon), for example, are −150.63 (11), −126.77 (13) and −138.76 (11)° for mol­ecules A, B and C, respectively, and the C—C—C—N torsion angles involving the ethyl C atoms are 102.90 (13), 87.81 (14) and 86.47 (13)°. The main difference between the three mol­ecules lies in the way they are arranged in the solid-state structure. All three mol­ecules form dimers that are connected through strong O—H⋯O hydrogen bonds with R 2 2(10) graph-set motifs. The symmetry of the dimers formed does however differ between mol­ecules. Mol­ecules B connect with each other to form inversion dimers. Mol­ecules A and C, on the other hand, form dimers with local twofold symmetry, but the two mol­ecules are crystallographically distinct. The B and C molecules are linked to themselves and to each other via C—H⋯O hydrogen bonds. This results in the formation of a three-dimensional network structure. PMID:23284535

  4. Mesoscopic simulation of a micellar poly(N-isopropyl acrylamide)-b-(polyethylene oxide) copolymer system

    NASA Astrophysics Data System (ADS)

    Bautista-Reyes, Rubén; Soto-Figueroa, César; Vicente, Luis

    2016-05-01

    In this article we studied the micellar formation of poly(N-isopropyl acrylamide)-b-polyethylene oxide (PNIPAM-b-PEO) copolymers in an aqueous system. From molecular simulations the dependence on temperature of the Flory-Huggins interaction parameter χ for PNIPAM and PEO in water is obtained and compared with available experimental results and values from other theoretical calculations. By means of dissipative particle dynamics (DPD) we then simulated the coil-globule transition for PNIPAM chains in water with a transition temperature of around 305 K. The simulations for PNIPAM-b-PEO copolymers showed that at room temperature the chains are miscible in an aqueous phase but with a temperature increase the system turns into micelles at T  =  305 K. The change in micelle anisotropy due to a different ratio PNIPAM/PEO of chains is also analyzed. What is observed is that for large PEO the large number of dissolved PEO chains gives a large corona size and the micelle is not spherical but obloide and as the number of PNIPAM is increased the micelle acquires a spherical shape. As an important application we considered the system micelle-water/anionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate [BMIM]+[PF6]-). By increasing the temperature of the system from 306 K it is shown that at T  =  345 K there is a transfer of the micelle from water to the ionic liquid phase and this was due to the change in the relative affinity of PEO to water and ionic liquid expressed by the change in χ. All the simulation outcomes are qualitatively consistent with experimental results and thus to our knowledge we give the first set of χ values for the interaction between PNIPAM and water in a wide range of temperature values.

  5. Dissociative Photoionization of Diethyl Ether.

    PubMed

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

    2015-10-29

    The dissociative photoionization of internal energy selected diethyl ether ions was investigated by imaging photoelectron photoion coincidence spectroscopy. In a large, 5 eV energy range Et2O(+) cations decay by two parallel and three sequential dissociative photoionization channels, which can be modeled well using statistical theory. The 0 K appearance energies of the CH3CHOCH2CH3(+) (H-loss, m/z = 73) and CH3CH2O═CH2(+) (methyl-loss, m/z = 59) fragment ions were determined to be 10.419 ± 0.015 and 10.484 ± 0.008 eV, respectively. The reemergence of the hydrogen-loss ion above 11 eV is attributed to transition-state (TS) switching, in which the second, outer TS is rate-determining at high internal energies. At 11.81 ± 0.05 eV, a secondary fragment of the CH3CHOCH2CH3(+) (m/z = 73) ion, protonated acetaldehyde, CH3CH═OH(+) (m/z = 45) appears. On the basis of the known thermochemical onset of this fragment, a reverse barrier of 325 meV was found. Two more sequential dissociation reactions were examined, namely, ethylene and formaldehyde losses from the methyl-loss daughter ion. The 0 K appearance energies of 11.85 ± 0.07 and 12.20 ± 0.08 eV, respectively, indicate no reverse barrier in these processes. The statistical model of the dissociative photoionization can also be used to predict the fractional ion abundances in threshold photoionization at large temperatures, which could be of use in, for example, combustion diagnostics. PMID:26444101

  6. Production of liquid hydrocarbon and ether mixtures

    SciTech Connect

    Harandi, M.N.; Owen, H.

    1989-05-16

    An integrated process is described for the production of ether-rich liquid fuels, comprising: (a) etherifying a mixture of excess lower alkyl alcohol and aliphatic hydrocarbon feedstock rich in C/sub 4/+isoalkenes in the presence of acid etherification catalyst whereby lower alkyl tertiary alkyl ethers are produced; (b) separating etherification effluent from step(a) to provide a gasoline stream rich in C/sub 5/+ ethers and a stream comprising unreacted alcohol and alkenes; (c) contacting the unreacted alcohol and alkenes with an acidic metallosilicate zeolite conversion catalyst under olefinic and oxygenates conversion conditions at a temperature of at least 200/sup 0/C (392/sup 0/F) whereby a conversion effluent stream rich in C/sub 4/+ isoalkenes is produced; (d) recycling at least a portion of the conversion effluent stream to step (a) for etherification.

  7. Fabricating photoswitches and field-effect transistors from self-assembled tetra(2-isopropyl-5-methyphenoxy) copper phthalocyanines nanowires.

    PubMed

    Cheng, Chuanwei; Gao, Junshan; Xu, Guoyue; Zhang, Haiqian; Li, Yingying; Luo, Yan

    2009-05-01

    Tetra(2-isopropyl-5-methyphenoxy) copper phthalocyanine (CuPc) nanowires synthesized by a facile, low temperature self-assembled route, were incorporated into nano-devices: photoswitch and organic field-effect transistor. The devices were capable of switching on/off reversibly and fast by turning the 808 nm infrared light on/off. And the carrier mobility micro of CuPc nanowires incorporated in the devices was -0.02 cm2/V x s. The prelimenary results in this study show the potential application of metal phthalocyanine nanowires in low-cost fabrication of nano photo-electric devices.

  8. [Has N-isopropyl-N'-phenylparaphenylenediamine a place among standard allergens? Importance of this allergen in rubber intolerance].

    PubMed

    Foussereau, J; Cavelier, C

    1977-01-01

    Allergic contact dermatitis to N-isopropyl-N'-phenylparaphenylenediamine (IPPD) from rubber is far from being exceptional. Out of a total of 56 cases of allergic contact dermatitis to IPPD, 42 were considered as caused by occupational contacts: 17 cases were found in tyre manufacturers, 9 in car-mechanics, 9 in drivers, and 7 in various industrial branches. Out of the 56 cases, 23 also reacted allergically to mercaptobenzothiazole or to tetramethylthiuramdisulphide, or to both of these substances. In a chromatographic analysis of samples of 9 different tyre brands, IPPD was found in 8 cases.

  9. Crystalline imide/arylene ether copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor); Hergenrother, Paul M. (Inventor); Bass, Robert G. (Inventor)

    1995-01-01

    Crystalline imide/arylene ether block copolymers are prepared by reacting anhydride terminated poly(amic acids) with amine terminated poly)arylene ethers) in polar aprotic solvents and chemically or thermally cyclodehydrating the resulting intermediate poly(amic acids). The block copolymers of the invention have one glass transition temperature or two, depending on the particular structure and/or the compatibility of the block units. Most of these crystalline block copolymers for tough, solvent resistant films with high tensile properties. While all of the copolymers produced by the present invention are crystalline, testing reveals that copolymers with longer imide blocks or higher imide content have increased crystallinity.

  10. 37. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, NORTHWEST CORNER OF BUILDING. BUILDING NO. 521 (ETHER VAULT) IN BACKGROUND LEFT. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  11. 41. LOOKING WEST AT BUILDING NO. 519, ETHER AND ALCOHOL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. LOOKING WEST AT BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, (LEFT) AND BUILDING NO. 521, ETHER VAULT, (RIGHT) IN FOREGROUND - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  12. Vinyl ethers containing an epoxy group. XVI. Reaction of glycidol vinyloxyethyl ether with acetals

    SciTech Connect

    Nedolya, N.A.; Khil'ko, M.Ya.; Trofimov, B.A.; Sigalov, M.V.

    1988-10-10

    In order to obtain branched acetals with epoxide groups (prospective monomers and intermediates) the authors investigated the reaction of acetaldehyde diethyl and di(1,1,3-trihydrotetrafluoropropyl) acetals with glycidol vinyloxyethyl ether. The addition of acetals to vinyl epoxy ethers was realized, and the first representative of compounds of this type, i.e., 9-glycidyloxy-6-ethoxy-4-methyl-3,7-dioxanonane, was obtained. It was also impossible to add a fluoroacetal to butyl vinyl ether (0.08-1.00 wt. % of catalyst CF/sub 3/COOH, BF/sub 3//times/ OEt/sub 2/, 20-80/degree/C, 0.5-3 h).

  13. 40 CFR 721.10669 - Tertiary amine alkyl ether (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tertiary amine alkyl ether (generic... Specific Chemical Substances § 721.10669 Tertiary amine alkyl ether (generic). (a) Chemical substance and... alkyl ether (PMN P-13-78) is subject to reporting under this section for the significant new...

  14. 40 CFR 721.10385 - Phenoxy alkyl ether (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenoxy alkyl ether (generic). 721... Substances § 721.10385 Phenoxy alkyl ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as phenoxy alkyl ether (PMN...

  15. 40 CFR 721.10385 - Phenoxy alkyl ether (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenoxy alkyl ether (generic). 721... Substances § 721.10385 Phenoxy alkyl ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as phenoxy alkyl ether (PMN...

  16. 40 CFR 721.10385 - Phenoxy alkyl ether (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phenoxy alkyl ether (generic). 721... Substances § 721.10385 Phenoxy alkyl ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as phenoxy alkyl ether (PMN...

  17. 40 CFR 721.10453 - Polyglycerin alkyl ether (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polyglycerin alkyl ether (generic... Specific Chemical Substances § 721.10453 Polyglycerin alkyl ether (generic). (a) Chemical substance and... alkyl ether (PMN P-02-796) is subject to reporting under this section for the significant new...

  18. 40 CFR 721.10453 - Polyglycerin alkyl ether (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyglycerin alkyl ether (generic... Specific Chemical Substances § 721.10453 Polyglycerin alkyl ether (generic). (a) Chemical substance and... alkyl ether (PMN P-02-796) is subject to reporting under this section for the significant new...

  19. 40 CFR 721.10669 - Tertiary amine alkyl ether (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tertiary amine alkyl ether (generic... Specific Chemical Substances § 721.10669 Tertiary amine alkyl ether (generic). (a) Chemical substance and... alkyl ether (PMN P-13-78) is subject to reporting under this section for the significant new...

  20. 21 CFR 520.1846 - Polyoxyethylene (23) lauryl ether blocks.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Polyoxyethylene (23) lauryl ether blocks. (a) Specifications. Each molasses-based block contains 2.2 percent polyoxyethylene (23) lauryl ether. (b) Sponsor. See No. 067949 in § 510.600(c) of this chapter. (c) Conditions of... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Polyoxyethylene (23) lauryl ether blocks....

  1. 21 CFR 520.1846 - Polyoxyethylene (23) lauryl ether blocks.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Polyoxyethylene (23) lauryl ether blocks. (a) Specifications. Each molasses-based block contains 2.2 percent polyoxyethylene (23) lauryl ether. (b) Sponsor. See No. 067949 in § 510.600(c) of this chapter. (c) Conditions of... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Polyoxyethylene (23) lauryl ether blocks....

  2. 21 CFR 520.1846 - Polyoxyethylene (23) lauryl ether blocks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Polyoxyethylene (23) lauryl ether blocks. (a) Specifications. Each molasses-based block contains 2.2 percent polyoxyethylene (23) lauryl ether. (b) Sponsor. See No. 067949 in § 510.600(c) of this chapter. (c) Conditions of... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Polyoxyethylene (23) lauryl ether blocks....

  3. 21 CFR 520.1846 - Polyoxyethylene (23) lauryl ether blocks.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Polyoxyethylene (23) lauryl ether blocks. (a) Specifications. Each molasses-based block contains 2.2 percent polyoxyethylene (23) lauryl ether. (b) Sponsor. See No. 067949 in § 510.600(c) of this chapter. (c) Conditions of... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Polyoxyethylene (23) lauryl ether blocks....

  4. 21 CFR 520.1846 - Polyoxyethylene (23) lauryl ether blocks.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Polyoxyethylene (23) lauryl ether blocks. (a) Specifications. Each molasses-based block contains 2.2 percent polyoxyethylene (23) lauryl ether. (b) Sponsor. See No. 067949 in § 510.600(c) of this chapter. (c) Conditions of... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Polyoxyethylene (23) lauryl ether blocks....

  5. 39. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, LOOKING AT SOUTHWEST CORNER WITH BUILDING NO. 521, ETHER VAULT, AND BUILDING NO. 519-A, ETHER & ALOCOHL STORAGE TANKS, IN BACKGROUND RIGHT. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  6. 40 CFR 721.10069 - Ether amine phosphonate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ether amine phosphonate (generic). 721... Substances § 721.10069 Ether amine phosphonate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as ether amine phosphonate (PMN...

  7. 40 CFR 721.3440 - Haloalkyl substituted cyclic ethers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Haloalkyl substituted cyclic ethers... Substances § 721.3440 Haloalkyl substituted cyclic ethers. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances haloalkyl substituted cyclic ethers (PMN P-85-368 and...

  8. 40 CFR 721.3486 - Polyglycerin mono(4-nonylphenyl) ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyglycerin mono(4-nonylphenyl) ether... Substances § 721.3486 Polyglycerin mono(4-nonylphenyl) ether. (a) Chemical substance and significant new uses...-nonylphenyl) ether (PMN P-94-2230) is subject to reporting under this section for the significant new...

  9. 40 CFR 721.3480 - Halogenated biphenyl glycidyl ethers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Halogenated biphenyl glycidyl ethers... Substances § 721.3480 Halogenated biphenyl glycidyl ethers. (a) Chemical substance and significant new uses... ethers (PMNs P-90-1844, P-90-1845, and P-90-1846) are subject to reporting under this section for...

  10. 40 CFR 721.3440 - Haloalkyl substituted cyclic ethers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Haloalkyl substituted cyclic ethers... Substances § 721.3440 Haloalkyl substituted cyclic ethers. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances haloalkyl substituted cyclic ethers (PMN P-85-368 and...

  11. 40 CFR 721.3480 - Halogenated biphenyl glycidyl ethers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated biphenyl glycidyl ethers... Substances § 721.3480 Halogenated biphenyl glycidyl ethers. (a) Chemical substance and significant new uses... ethers (PMNs P-90-1844, P-90-1845, and P-90-1846) are subject to reporting under this section for...

  12. 40 CFR 721.10069 - Ether amine phosphonate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ether amine phosphonate (generic). 721... Substances § 721.10069 Ether amine phosphonate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as ether amine phosphonate (PMN...

  13. 40 CFR 721.3500 - Perhalo alkoxy ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Perhalo alkoxy ether. 721.3500 Section... Substances § 721.3500 Perhalo alkoxy ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as perhalo alkoxy ether (PMN P-83-1227)...

  14. 40 CFR 721.3420 - Brominated arylalkyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated arylalkyl ether. 721.3420... Substances § 721.3420 Brominated arylalkyl ether. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as brominated arylalkyl ether (P-83-906)...

  15. 40 CFR 721.3465 - Stilbene diglycidyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Stilbene diglycidyl ether. 721.3465... Substances § 721.3465 Stilbene diglycidyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as stilbene diglycidyl ether (PMN P-96-1427) is subject...

  16. 40 CFR 721.3465 - Stilbene diglycidyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Stilbene diglycidyl ether. 721.3465... Substances § 721.3465 Stilbene diglycidyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as stilbene diglycidyl ether (PMN P-96-1427) is subject...

  17. 40 CFR 721.3438 - Chlorohydroxyalkyl butyl ether (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Chlorohydroxyalkyl butyl ether... Specific Chemical Substances § 721.3438 Chlorohydroxyalkyl butyl ether (generic). (a) Chemical substance... chlorohydroxyalkyl butyl ether (PMN P-99-1295) is subject to reporting under this section for the significant new...

  18. 40 CFR 721.3500 - Perhalo alkoxy ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Perhalo alkoxy ether. 721.3500 Section... Substances § 721.3500 Perhalo alkoxy ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as perhalo alkoxy ether (PMN P-83-1227)...

  19. 40 CFR 721.3430 - 4-Bromophenyl phenyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 4-Bromophenyl phenyl ether. 721.3430... Substances § 721.3430 4-Bromophenyl phenyl ether. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance 4-bromophenyl phenyl ether (CAS No. 101-55-3) is subject to...

  20. 40 CFR 721.3520 - Aliphatic polyglycidyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aliphatic polyglycidyl ether. 721.3520... Substances § 721.3520 Aliphatic polyglycidyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance aliphatic polyglycidyl ether (PMN P-89-1036) is subject...

  1. 40 CFR 721.3486 - Polyglycerin mono(4-nonylphenyl) ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polyglycerin mono(4-nonylphenyl) ether... Substances § 721.3486 Polyglycerin mono(4-nonylphenyl) ether. (a) Chemical substance and significant new uses...-nonylphenyl) ether (PMN P-94-2230) is subject to reporting under this section for the significant new...

  2. 40 CFR 721.3550 - Dipropylene glycol dimethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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...

  3. 40 CFR 721.3420 - Brominated arylalkyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Brominated arylalkyl ether. 721.3420... Substances § 721.3420 Brominated arylalkyl ether. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as brominated arylalkyl ether (P-83-906)...

  4. 40 CFR 721.3438 - Chlorohydroxyalkyl butyl ether (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Chlorohydroxyalkyl butyl ether... Specific Chemical Substances § 721.3438 Chlorohydroxyalkyl butyl ether (generic). (a) Chemical substance... chlorohydroxyalkyl butyl ether (PMN P-99-1295) is subject to reporting under this section for the significant new...

  5. 40 CFR 721.3520 - Aliphatic polyglycidyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aliphatic polyglycidyl ether. 721.3520... Substances § 721.3520 Aliphatic polyglycidyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance aliphatic polyglycidyl ether (PMN P-89-1036) is subject...

  6. 40 CFR 721.3550 - Dipropylene glycol dimethyl ether.

    Code of Federal Regulations, 2010 CFR

    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...

  7. 40 CFR 721.3430 - 4-Bromophenyl phenyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 4-Bromophenyl phenyl ether. 721.3430... Substances § 721.3430 4-Bromophenyl phenyl ether. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance 4-bromophenyl phenyl ether (CAS No. 101-55-3) is subject to...

  8. 40 CFR 721.10551 - Bisphenol S mono ether (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Bisphenol S mono ether (generic). 721... Substances § 721.10551 Bisphenol S mono ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as bisphenol S mono ether (PMN...

  9. 40 CFR 721.10551 - Bisphenol S mono ether (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Bisphenol S mono ether (generic). 721... Substances § 721.10551 Bisphenol S mono ether (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as bisphenol S mono ether (PMN...

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Dimensionally Stable Ether-Containing Polyimide Copolymers

    NASA Technical Reports Server (NTRS)

    Fay, Catharine C. (Inventor); St.Clair, Anne K. (Inventor)

    1999-01-01

    Novel polyimide copolymers containing ether linkages were prepared by the reaction of an equimolar amount of dianhydride and a combination of diamines. The polyimide copolymers described herein possess the unique features of low moisture uptake, dimensional stability, good mechanical properties, and moderate glass transition temperatures. These materials have potential application as encapsulants and interlayer dielectrics.

  12. Elastic electron scattering by ethyl vinyl ether

    NASA Astrophysics Data System (ADS)

    Khakoo, M. A.; Hong, L.; Kim, B.; Winstead, C.; McKoy, V.

    2010-02-01

    We report measured and calculated results for elastic scattering of low-energy electrons by ethyl vinyl ether (ethoxyethene), a prototype system for studying indirect dissociative attachment processes that may play a role in DNA damage. The integral cross section displays the expected π* shape resonance. The agreement between the calculated and measured cross sections is generally good.

  13. POLYBROMINATED DIPHENYL ETHERS IN SOUTHERN MISSISSIPPI CATFISH

    EPA Science Inventory

    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...

  14. Methyl tert-butyl ether (MTBE)

    Integrated Risk Information System (IRIS)

    Methyl tert - butyl ether ( MTBE ) ; CASRN 1634 - 04 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments f

  15. Bis(2-chloro-1-methylethyl) ether

    Integrated Risk Information System (IRIS)

    Bis ( 2 - chloro - 1 - methylethyl ) ether ; CASRN 108 - 60 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assess

  16. Ethylene glycol monobutyl ether (EGBE) (2-Butoxyethanol)

    Integrated Risk Information System (IRIS)

    Ethylene glycol monobutyl ether ( EGBE ) ( 2 - Butoxyethanol ) ; CASRN 111 - 76 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I (

  17. Orphan enzymes in ether lipid metabolism.

    PubMed

    Watschinger, Katrin; Werner, Ernst R

    2013-01-01

    Ether lipids are an emerging class of lipids which have so far not been investigated and understood in every detail. They have important roles as membrane components of e.g. lens, brain and testis, and as mediators such as platelet-activating factor. The metabolic enzymes for biosynthesis and degradation have been investigated to some extent. As most involved enzymes are integral membrane proteins they are tricky to handle in biochemical protocols. The sequence of some ether lipid metabolising enzymes has only recently been reported and other sequences still remain obscure. Defined enzymes without assigned sequence are known as orphan enzymes. One of these enzymes with uncharacterised sequence is plasmanylethanolamine desaturase, a key enzyme for the biosynthesis of one of the most abundant phospholipids in our body, the plasmalogens. This review aims to briefly summarise known functions of ether lipids, give an overview on their metabolism including the most prominent members, platelet-activating factor and the plasmalogens. A special focus is set on the description of orphan enzymes in ether lipid metabolism and on the successful strategies how four previous orphans have recently been assigned a sequence. Only one of these four was characterised by classical protein purification and sequencing, whereas the other three required alternative strategies such as bioinformatic candidate gene selection and recombinant expression or development of an inhibitor and multidimensional metabolic profiling.

  18. Imide/arylene ether block copolymers

    NASA Technical Reports Server (NTRS)

    Jensen, B. J.; Hergenrother, P. M.; Bass, R. G.

    1991-01-01

    Two series of imide/arylene either block copolymers were prepared using an arylene ether block and either an amorphous or semi-crystalline imide block. The resulting copolymers were characterized and selected physical and mechanical properties were determined. These results, as well as comparisons to the homopolymer properties, are discussed.

  19. "Crown Ether" Synthesis: An Organic Laboratory Experiment.

    ERIC Educational Resources Information Center

    Field, Kurt W.; And Others

    1979-01-01

    This experiment is designed to acquaint the student with a macromolecular synthesis of a crown ether type compound. The starting materials are readily available and the product, a cyclic polyether, belongs to a class of compounds that has aroused the interest of chemist and biologist alike. (Author/BB)

  20. POLYBROMINATED DIPHENYL ETHERS IN US SOILS

    EPA Science Inventory

    Chemical analysis of thirty-three soil samples from 15 US states reveals Polybrominated Diphenyl Ethers (PBDEs), in every sample.PBDE concentrations rangefrom 0.09 to 1200 parts per billion by mass. These data are the first analysis of soil concentrations of PBDEs in soils from a...

  1. A Comparison Study: The New Extended Shelf Life Isopropyl Ester PMR Technology versus The Traditional Methyl Ester PMR Approach

    NASA Technical Reports Server (NTRS)

    Alston, William B.; Scheiman, Daniel A.; Sivko, Gloria S.

    2005-01-01

    Polymerization of Monomeric Reactants (PMR) monomer solutions and carbon cloth prepregs of PMR II-50 and VCAP-75 were prepared using both the traditional limited shelf life methanol based PMR approach and a novel extended shelf life isopropanol based PMR approach. The methyl ester and isopropyl ester based PMR monomer solutions and PMR prepregs were aged for up to four years at freezer and room temperatures. The aging products formed were monitored using high pressure liquid chromatography (HPLC). The composite processing flow characteristics and volatile contents of the aged prepregs were also correlated versus room temperature storage time. Composite processing cycles were developed and six ply cloth laminates were fabricated with prepregs after various extended room temperature storage times. The composites were then evaluated for glass transition temperature (Tg), thermal decomposition temperature (Td), initial flexural strength (FS) and modulus (FM), long term (1000 hours at 316 C) thermal oxidative stability (TOS), and retention of FS and FM after 1000 hours aging at 316 C. The results for each ester system were comparable. Freezer storage was found to prevent the formation of aging products for both ester systems. Room temperature storage of the novel isopropyl ester system increased PMR monomer solution and PMR prepreg shelf life by at least an order of magnitude while maintaining composite properties.

  2. Process for making propenyl ethers and photopolymerizable compositions containing them

    DOEpatents

    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.

  3. Process for making propenyl ethers and photopolymerizable compositions containing them

    DOEpatents

    Crivello, J.V.

    1996-01-23

    Propenyl ether monomers of formula A(OCH{double_bond}CHCH{sub 3}){sub n} (V) 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.

  4. Certain glycol ethers eliminated from toxic chemical release reporting requirements

    SciTech Connect

    1994-09-01

    Effective June 28, 1994, the U.S. Environmental Protection Agency (EPA) eliminated high molecular weight glycol ethers from the reporting requirements of section 313 of the Emergency Planning and Community Right-To-Know Act of 1986 (EPCRA). EPCRA (42 U.S.C. 11023) is also referred to as Title III of the Superfund Amendments and Reauthorization Act (SARA) of 1986. EPA redefined the glycol ethers category list of chemicals subject to reporting based on an EPA review of available human health data on short-chain glycol ethers. EPA is removing only the surfactant glycol ethers, which are high molecular weight glycol ethers, i.e., those with pendant alkyl groups and that typically have eight or more carbon atoms. The redefinition retains certain glycol ethers (i.e., ethylene glycol ethers where there are 1,2, or 3 repeating ethylene oxide groups) in the category. These are reasonably anticipated to cause adverse human health effects.

  5. Cyclic ethers adsorbed on Ru(001)

    NASA Astrophysics Data System (ADS)

    Walczak, M. M.; Thiel, P. A.

    1990-11-01

    The three cyclic ethers 1,3-dioxane. 1,4-dioxane and 1,3,5-trioxane all exhibit multiple desorption states from Ru(001) between 200 and 310 K, in addition to the multilayer and metastable states at lower temperature. Most distinctive are the two low-temperature α-states. which are similar in shape, position, and relative population for all three compounds. This suggests that these states are associated with configurations which are accessible to all three molecules. The data also indicate that there is some molecular decomposition to gaseous CO and H 2. 1,4-Dioxane yields the largest amounts of these decomposition products, suggesting that this molecule is most susceptible to surface-catalyzed decomposition. The desorption data for the three cyclic ethers are grossly similar to each other, and also to the straight-chain diethers which we have previously studied.

  6. Ether bridge formation in loline alkaloid biosynthesis

    PubMed Central

    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.

    2014-01-01

    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 differing in alkaloid profiles were sequenced, revealing that those with mutated lolO accumulated exo-1-acetamidopyrrolizidine but no lolines. Heterologous expression of wild-type lolO complemented a lolO mutant, resulting in the production of N-acetylnorloline. These results indicated that the non-heme iron oxygenase, LolO, is required for ether bridge formation, probably through oxidation of exo-1-acetamidopyrrolizidine. PMID:24374065

  7. Synthesis and utility of fluorogenic acetoxymethyl ethers.

    PubMed

    Lavis, Luke D; Chao, Tzu-Yuan; Raines, Ronald T

    2011-01-01

    Phenolic fluorophores such as fluorescein, Tokyo Green, resorufin, and their derivatives are workhorses of biological science. Acylating the phenolic hydroxyl group(s) in these fluorophores masks their fluorescence. The ensuing ester is a substrate for cellular esterases, which can restore fluorescence. These esters are, however, notoriously unstable to hydrolysis, severely compromising their utility. The acetoxymethyl (AM) group is an esterase-sensitive motif that can mask polar functionalities in small molecules. Here, we report on the use of AM ether groups to mask phenolic fluorophores. The resulting profluorophores have a desirable combination of low background fluorescence, high chemical stability, and high enzymatic reactivity, both in vitro and in cellulo. These simple phenyl ether-based profluorophores could supplement or supplant the use of phenyl esters for imaging biochemical and biological systems.

  8. Poly(Arylene Ether Imidazole) Surface Films

    NASA Technical Reports Server (NTRS)

    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.

  9. Unconventional preparation of racemic crystals of isopropyl 3,3,3-trifluoro-2-hydroxypropanoate and their unusual crystallographic structure: the ultimate preference for homochiral intermolecular interactions.

    PubMed

    Aceña, José Luis; Sorochinsky, Alexander E; Katagiri, Toshimasa; Soloshonok, Vadim A

    2013-01-14

    This work reports the first example of the transformation of conglomerate (R)- and (S)-crystals into racemic crystals via sublimation. Crystallographic analysis of racemic isopropyl 3,3,3-trifluoro-2-hydroxypropanoate did not reveal the highly expected heterochiral dimer indicating that this compound is capable of forming exclusively homochiral oligomers via infinite multi-centred H-bonding networks.

  10. Rhodium-Catalyzed Dehydrogenative Silylation of Acetophenone Derivatives: Formation of Silyl Enol Ethers versus Silyl Ethers.

    PubMed

    Garcés, Karin; Lalrempuia, Ralte; Polo, Víctor; Fernández-Alvarez, Francisco J; García-Orduña, Pilar; Lahoz, Fernando J; Pérez-Torrente, Jesús J; Oro, Luis A

    2016-10-01

    A series of rhodium-NSiN complexes (NSiN=bis (pyridine-2-yloxy)methylsilyl fac-coordinated) is reported, including the solid-state structures of [Rh(H)(Cl)(NSiN)(PCy3 )] (Cy=cyclohexane) and [Rh(H)(CF3 SO3 )(NSiN)(coe)] (coe=cis-cyclooctene). The [Rh(H)(CF3 SO3 )(NSiN)(coe)]-catalyzed reaction of acetophenone with silanes performed in an open system was studied. Interestingly, in most of the cases the formation of the corresponding silyl enol ether as major reaction product was observed. However, when the catalytic reactions were performed in closed systems, formation of the corresponding silyl ether was favored. Moreover, theoretical calculations on the reaction of [Rh(H)(CF3 SO3 )(NSiN)(coe)] with HSiMe3 and acetophenone showed that formation of the silyl enol ether is kinetically favored, while the silyl ether is the thermodynamic product. The dehydrogenative silylation entails heterolytic cleavage of the Si-H bond by a metal-ligand cooperative mechanism as the rate-determining step. Silyl transfer from a coordinated trimethylsilyltriflate molecule to the acetophenone followed by proton transfer from the activated acetophenone to the hydride ligand results in the formation of H2 and the corresponding silyl enol ether.

  11. Rhodium-Catalyzed Dehydrogenative Silylation of Acetophenone Derivatives: Formation of Silyl Enol Ethers versus Silyl Ethers.

    PubMed

    Garcés, Karin; Lalrempuia, Ralte; Polo, Víctor; Fernández-Alvarez, Francisco J; García-Orduña, Pilar; Lahoz, Fernando J; Pérez-Torrente, Jesús J; Oro, Luis A

    2016-10-01

    A series of rhodium-NSiN complexes (NSiN=bis (pyridine-2-yloxy)methylsilyl fac-coordinated) is reported, including the solid-state structures of [Rh(H)(Cl)(NSiN)(PCy3 )] (Cy=cyclohexane) and [Rh(H)(CF3 SO3 )(NSiN)(coe)] (coe=cis-cyclooctene). The [Rh(H)(CF3 SO3 )(NSiN)(coe)]-catalyzed reaction of acetophenone with silanes performed in an open system was studied. Interestingly, in most of the cases the formation of the corresponding silyl enol ether as major reaction product was observed. However, when the catalytic reactions were performed in closed systems, formation of the corresponding silyl ether was favored. Moreover, theoretical calculations on the reaction of [Rh(H)(CF3 SO3 )(NSiN)(coe)] with HSiMe3 and acetophenone showed that formation of the silyl enol ether is kinetically favored, while the silyl ether is the thermodynamic product. The dehydrogenative silylation entails heterolytic cleavage of the Si-H bond by a metal-ligand cooperative mechanism as the rate-determining step. Silyl transfer from a coordinated trimethylsilyltriflate molecule to the acetophenone followed by proton transfer from the activated acetophenone to the hydride ligand results in the formation of H2 and the corresponding silyl enol ether. PMID:27553810

  12. The crystal structure of an isopenicillin N synthase complex with an ethereal substrate analogue reveals water in the oxygen binding site.

    PubMed

    Clifton, Ian J; Ge, Wei; Adlington, Robert M; Baldwin, Jack E; Rutledge, Peter J

    2013-08-19

    Isopenicillin N synthase (IPNS) is a non-heme iron oxidase central to the biosynthesis of β-lactam antibiotics. IPNS converts the tripeptide δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine (ACV) to isopenicillin N while reducing molecular oxygen to water. The substrate analogue δ-(L-α-aminoadipoyl)-L-cysteinyl-O-methyl-D-threonine (ACmT) is not turned over by IPNS. Epimeric δ-(L-α-aminoadipoyl)-L-cysteinyl-O-methyl-D-allo-threonine (ACmaT) is converted to a bioactive penam product. ACmT and ACmaT differ from each other only in the stereochemistry at the β-carbon atom of their third residue. These substrates both contain a methyl ether in place of the isopropyl group of ACV. We report an X-ray crystal structure for the anaerobic IPNS:Fe(II):ACmT complex. This structure reveals an additional water molecule bound to the active site metal, held by hydrogen-bonding to the ether oxygen atom of the substrate analogue.

  13. Incinerating volatile organic compounds with ferrospinel catalyst MnFe2O4: an example with isopropyl alcohol.

    PubMed

    Lou, Jie-Chung; Tu, Yao-Jen

    2005-12-01

    This paper concerns the incineration of isopropyl alcohol (IPA) using the ferrospinel catalyst MnFe2O4. It covers the preparation of the ferrospinel catalyst, the screening of catalytic activity, catalytic incineration testing, and 72-hr decay testing of the catalyst. The experimental results of catalyst screening reveal that the Mn/Fe catalyst is the best of five prepared catalysts (chromium/iron [Cr/Fe], manganese/iron [Mn/Fe], zinc/iron [Zn/Fe], nickel/iron [Ni/Fe], and pure magnetite [Fe3O4]). In tests of the catalytic incineration system used to convert IPA, 98% conversion was obtained at a space velocity of 24,000 hr(-1), an oxygen (O2) content of 21%, 1700 ppm of IPA, and a reaction temperature of 200 degrees C.

  14. trans-Dichloridobis[dicyclo-hex-yl(4-isopropyl-phen-yl)phosphane-κP]platinum(II) acetone monosolvate.

    PubMed

    Vuba, Bubele; Muller, Alfred

    2012-01-01

    The title compound, [PtCl(2)(C(21)H(33)P)(2)]·C(3)H(6)O, crystallizes with an accompanying acetone solvent mol-ecule. The metal atom shows a distorted square-planar coordination environment, with a P-Pt-P angle of 172.41 (3)° as the most prominent feature. Both isopropyl fragments were treated as disordered over two conformations with occupancy ratios of 0.55 (2):0.45 (2) and 0.58 (2):0.42 (2). The solvent mol-ecule was also disordered over two orientations in a 1:1 ratio. The crystal studied was a non-merohedral twin with a twin component of 32.4%.

  15. Analysis of methylphosphonic acid, ethyl methylphosphonic acid and isopropyl methylphosphonic acid at low microgram per liter levels in groundwater.

    PubMed

    Sega, G A; Tomkins, B A; Griest, W H

    1997-11-28

    A method is described for determining methylphosphonic acid, ethyl methylphosphonic acid and isopropyl methylphosphonic acid, which are hydrolysis products of the nerve agents VX (S-2-diisopropylaminoethyl O-ethyl methylphosphonothiolate) and GB (sarin, isopropylmethyl phosphonofluoridate). The analytes are extracted from 50 ml groundwater using a solid-phase extraction column packed with 500 mg of silica with a bonded quaternary amine phase, and are eluted and derivatized with methanolic trimethylphenylammonium hydroxide. Separation and quantitation are achieved using a capillary column gas chromatograph equipped with a flame photometric detector operated in its phosphorus-selective mode. Two independent statistically-unbiased procedures were employed to determine the detection limits, which ranged between 3 and 9 micrograms/l, for the three analytes. PMID:9435117

  16. Structural investigation of thermo-responsive poly(2-isopropyl-2-oxazoline) hydrogel across the volume phase transition.

    PubMed

    Li, Tianjiao; Tang, Hui; Wu, Peiyi

    2015-03-14

    The deswelling and swelling behaviors of poly(2-isopropyl-2-oxazoline)-based hydrogel synthesized by a one-pot microwave-assisted solvent-free reaction were investigated. A distinct hydrophobic collapse of the hydrogel compared with the corresponding aqueous solution was observed by FT-IR spectroscopy combined with two-dimensional correlation spectroscopy (2DCOS) and perturbation-correlation moving-window (PCMW) analyses. The volume phase transition (VPT) temperature of 35 °C during heating and the transition temperature range of 41-30 °C during cooling were determined, indicating different dynamic transition mechanisms during heating and cooling. Water expulsion starting from the benzene ring-centered hydrophobic spots to the surroundings was revealed during deswelling. However, during swelling, although the rebuilding of cross-linking hydrogen bond bridges provided a channel-like microstructure to reswell the hydrogel gradually, a slow, unusual recovery of the amide hydrogen bonds to water molecules was observed. PMID:25611904

  17. Prediction of language and neurologic recovery after cerebral infarction with SPECT imaging using N-isopropyl-p-(I-123) iodoamphetamine

    SciTech Connect

    Bushnell, D.L.; Gupta, S.; Mlcoch, A.G.; Barnes, W.E.

    1989-06-01

    Fourteen patients (10 with left-sided and 4 with right-sided cerebral infarction) were prospectively studied with single-photon emission computed tomography (SPECT) using N-isopropyl-p-(I-123) iodoamphetamine (IMP, SPECTamine) to determine its usefulness in predicting neurologic/language recovery after cerebral infarction. All neuro-SPECT imaging was performed within 30 days after infarction. Detailed assessment of neurologic and/or language recovery (after 3 months) was carried out prospectively in each patient. Patients with smaller volume IMP defects in the region of infarction demonstrated significantly better neurologic and language recovery than patients with large IMP defects. Analysis of the IMP ''redistribution'' phenomenon failed to demonstrate definitively a relationship with clinical recovery. It was concluded that the volume of the IMP defect can aid in predicting recovery potential after cerebral infarction.

  18. Unexpected carbon-carbon coupling between organic cyanides and isopropyl {beta}-carbon in a hafnium ene diamide complex

    SciTech Connect

    Bol, J.E.; Hessen, B.; Teuben, J.H.; Smeets, W.J.J.; Spek, A.L.

    1992-06-01

    Reaction of the ene diamide complex Cp*Hf({sigma}{sup 2},{pi}-iPr-DAB)Cl (1; Cp* = {eta}{sup 5}-C{sub 5}Me{sub 5}, iPr-DAB = 1,4-diisopropyl-1,4-diaza-1,3-butadiene) with organic cyanides was investigated. The crystal structure of the product, Cp*Hf[iPrNCH{double_bond}CHNC(Me){double_bond}CHC(tBu){double_bond}NH]Cl, is reported. The reaction is thought to proceed by two hydrogen transfers and a C-C coupling on the {beta}-carbon of an isopropyl group. NMR was used to identify reaction intermediates in the hydrogen transfer scheme.

  19. Nikola Tesla, the Ether and his Telautomaton

    NASA Astrophysics Data System (ADS)

    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.

  20. Promoting environmentally sound management of polybrominated diphenyl ethers in Asia.

    PubMed

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

    2014-06-01

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

  1. Measurement of polybrominated diphenyl ethers on hand wipes: estimating exposure from hand-to-mouth contact.

    PubMed

    Stapleton, Heather M; Kelly, Shannon M; Allen, Joseph G; Mcclean, Michael D; Webster, Thomas F

    2008-05-01

    Estimates of exposure to the flame-retardant polybrominated diphenyl ethers (PBDEs) in dust are very poor due to limited knowledge about dust ingestion. This study was undertaken to determine if PBDEs could be measured on hand wipes, and if so, to determine the distribution of levels present on the skin surface area to provide preliminary exposure estimates from hand-to-mouth contact. Hand wipes were collected from 33 individuals residing in the United States using sterile gauze pads soaked in isopropyl alcohol. The total PBDE residue collected on the wipes ranged from 2.60 to 1982 ng, with a median value of 130 ng, or normalized to hand surface area, a concentration of 135 pg/cm2. The fully brominated congener, BDE 209, was also detected and ranged from < DL to 270 ng with a median value of 26 ng. Congener patterns observed on the wipes were similar to patterns observed in house dust samples, consisting of congeners associated with the PentaBDE and DecaBDE mixtures, suggesting that the source of PBDEs to the hands may be dust particles. However, PBDE hand residues may also be a result of direct contact with PBDE-laden products, leading to adsorption to the skin surface oils. Repeated wipe sampling from three individuals suggests that sigmaPBDE levels on the hand may be relatively consistent for some individuals but not for others. Furthermore, levels of sigmaPBDEs were greater on the bottom of the hands relative to the top of the hands. Using these values we have calculated potential human exposure from hand-to-mouth contact. The median exposure estimates for children and adults are 1380 and 154 ng/day, respectively, whereas the 95th percentile exposure estimates were 6090 and 677 ng/day, respectively. These estimates are greater than dietary intake rates and suggest hand-to-mouth contact may be a key exposure route for PBDEs.

  2. Chemistry and adhesive properties of poly(arylene ether)s containing heterocyclic units

    NASA Technical Reports Server (NTRS)

    Connell, John W.

    1991-01-01

    Novel poly(arylene ether)s containing heterocyclic units were prepared, characterized, and evaluated as adhesives and composite matrices. The polymers were prepared by reacting a heterocyclic bisphenol with an activated aromatic dihalide in a polar aprotic solvent, using potassium carbonate. The polymerizations were generally carried out in N,N-dimethylacetamide at 155 C. In some cases, where the polymers were semicrystalline, higher temperatures and thus higher boiling solvents were necessary to keep the polymers in solution. Heterocyclic rings incorporated into the poly(arylene ether) backbone include phenylquinoxaline, phenylimidazole, benzimidazole, benzoxazole, 1,3,4-oxadiazole, and 1,2,4-triazole. The polymers were characterized by differential scanning calorimetry, solution viscosity, X-ray diffraction, thin film, and adhesive and (in some cases) composite properties. The glass transition temperatures, crystalline melt temperature, solubility, and mechanical properties varied depending upon the heterocyclic ring. The chemistry and properties of these materials are discussed.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Photolysis of Low-Brominated Diphenyl Ethers and Their Reactive Oxygen Species-Related Reaction Mechanisms in an Aqueous System

    PubMed Central

    Wang, Mei; Wang, Huili; Zhang, Rongbo; Ma, Meiping; Mei, Kun; Fang, Fang; Wang, Xuedong

    2015-01-01

    To date, no report was concerned with participation of reactive oxygen species in waters during photolysis of low-brominated diphenyl ethers (LBDEs). Herein, we found that electron spin resonance (ESR) signals rapidly increased with increasing irradiation time in the solution of LBDEs and 4-oxo-TMP solutions. But this phenomenon did not occur in the presence of NaN3 (1O2 quencher) demonstrating generation of 1O2 in process of LBDEs photolysis. The indirect photolytic contribution rate for BDE-47 and BDE-28 was 18.8% and 17.3% via 1O2, and 4.9% and 6.6% via ·OH, respectively. Both D2O and NaN3 experiments proved that the indirect photolysis of LBDEs was primarily attributable to 1O2. The bimolecular reaction rate constants of 1O2 with BDE-47 and BDE-28 were 3.12 and 3.64 × 106 M-1 s-1, respectively. The rate constants for BDE-47 and BDE-28 (9.01 and 17.52 × 10−3 min-1), added to isopropyl alcohol, were very close to those (9.65 and 18.42 × 10−3 min-1) in water, proving the less indirect photolytic contribution of ·OH in water. This is the first comprehensive investigation examining the indirect photolysis of LBDEs in aqueous solution. PMID:26274605

  5. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  6. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  7. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  8. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  9. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  10. Antioxidant activity of alkyl hydroxytyrosyl ethers in unsaturated lipids.

    PubMed

    Cert, Rosa; Madrona, Andrés; Espartero, José Luis; Pérez-Camino, M Carmen

    2015-06-01

    The antioxidant activity of ethyl and octyl hydroxytyrosyl ethers toward lipids was determined using the Rancimat and open cup methods at high temperatures and 50 °C, respectively. The effect of the unsaturation of the matrix was evaluated using sunflower, soya, and fish refined oils. The antioxidant activities of alkyl hydroxytyrosyl ethers (HTy ethers), hydroxytyrosyl esters, and free hydroxytyrosol are similar, and are much higher than that of α-tocopherol at the same millimolar concentration. The relationship between the induction period and the concentration of the HTy ethers is a sigmoidal curve; an accurate concentration of HTy ethers is necessary to achieve maximum activity, as it increases with the level of matrix unsaturation. The presence of tocopherols in commercial oils affects the antioxidant effect of HTy ethers. Thus, the addition of a low concentration of HTy ethers results in a positive effect, whereas the effect of the addition of high amounts of ethers is slightly less than that of the phenol alone. The addition of HTy ethers to commercial refined oils increases the stability of the oils and preserves tocopherols and polyunsaturated fatty acids from oxidation, enabling the oils to maintain their nutritional properties for longer periods of time.

  11. Divinyl ether synthase gene, and protein and uses thereof

    DOEpatents

    Howe, Gregg A.; Itoh, Aya

    2006-12-26

    The present invention relates to divinyl ether synthase genes, proteins, and methods of their use. The present invention encompasses both native and recombinant wild-type forms of the synthase, as well as mutants and variant forms, some of which possess altered characteristics relative to the wild-type synthase. The present invention also relates to methods of using divinyl ether synthase genes and proteins, including in their expression in transgenic organisms and in the production of divinyl ether fatty acids, and to methods of suing divinyl ether fatty acids, including in the protection of plants from pathogens.

  12. Divinyl ether synthase gene and protein, and uses thereof

    DOEpatents

    Howe, Gregg A.; Itoh, Aya

    2011-09-13

    The present invention relates to divinyl ether synthase genes, proteins, and methods of their use. The present invention encompasses both native and recombinant wild-type forms of the synthase, as well as mutants and variant forms, some of which possess altered characteristics relative to the wild-type synthase. The present invention also relates to methods of using divinyl ether synthase genes and proteins, including in their expression in transgenic organisms and in the production of divinyl ether fatty acids, and to methods of suing divinyl ether fatty acids, including in the protection of plants from pathogens.

  13. Facile cleavage of triethylsilyl (TES) ethers using o-iodoxybenzoic acid (IBX) without affecting tert-butyldimethylsilyl (TBS) ethers.

    PubMed

    Wu, Yikang; Huang, Jia-Hui; Shen, Xin; Hu, Qi; Tang, Chao-Jun; Li, Liang

    2002-06-27

    [reaction: see text] In DMSO cleavage of triethylsilyl (TES) ethers by o-iodoxybenzoic acid (IBX) was significantly faster than cleavage of tert-butyldimethylsilyl (TBS) ethers or further oxidation into carbonyl compounds. In most cases, TES protecting groups could be removed in good to excellent yields within 1 h, whereas similar TBS protecting groups remained intact under the same conditions. The procedure also could be adapted for direct one-pot conversion of TES ethers into carbonyl compounds.

  14. Brominated-chlorinated diphenyl ethers formed by thermolysis of polybrominated diphenyl ethers at low temperatures.

    PubMed

    Rupp, Silke; Metzger, Jörg W

    2005-09-01

    Polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants (BFRs) used mainly as additives in different kinds of plastic material. Various PBDEs are found in all environmental compartments as well as in tissue and blood serum of animals and humans due to their persistence and tendency to bioaccumulate. Emission of PBDEs into the environment can occur during recycling of PBDE-containing plastic material or during their uncontrolled or insufficient combustion as e.g. in accidental fires or landfill fires. Under these circumstances, PBDEs can also function as precursor molecules for the formation of polybrominated dibenzodioxins (PBDDs) and dibenzofurans (PBDFs). In this study, we qualitatively investigated the reaction of two PBDE congeners, 2,2',4,4'-tetrabromo diphenyl ether (BDE 47) and 2,2',4,4',5,5'-hexabromo diphenyl ether (BDE 153), as well as hexabromobenzene (HBB), a flame retardant used in the past, when exposed to temperatures between 250 degrees C and 500 degrees C. The formed reaction products were analysed by high resolution gas chromatography-low resolution mass spectrometry (HRGC-LRMS). Among others brominated-chlorinated diphenyl ethers were formed by chlorodebromination of the PBDEs. In addition, thermolysis of BDE 47 and BDE 153 in the presence of tetrachloromethane as model substance for an organic chlorine source was studied. Thermal treatment of HBB resulted in the formation of brominated-chlorinated benzenes. PMID:16083771

  15. Antifungal ether diglycosides from Matayba guianensis Aublet.

    PubMed

    de Assis, Polyana A; Theodoro, Phellipe N E T; de Paula, José E; Araújo, Ana J; Costa-Lotufo, Letícia V; Michel, Sylvie; Grougnet, Raphaël; Kritsanida, Marina; Espindola, Laila S

    2014-03-01

    Since the 1960s, fungal infections have become a major worldwide public health problem. Antifungal treatments have many limitations, such as toxicity and resistance. Matayba guianensis Aublet (Sapindaceae) was chemically investigated as part of our ongoing search for lead molecules against fungi in the Brazilian Cerrado biome. The ethanolic extract of M. guianensis root bark revealed the presence of two previously unreported ether diglycosides: matayoside E (1) and F (2) with anti Candida activity, along with two known compounds: cupanioside (3) and stigmasterol (4).

  16. Antifungal activity of some diaryl ethers.

    PubMed

    Xu, Hui; Jian, Kun-Zhong; Guan, Qiu; Ye, Fei; Lv, Min

    2007-12-01

    Several diaryl ethers were synthesized and tested in vitro against seven phytopathogenic fungi, namely Fusarium graminearum, Alternaria alternate, Helminthosporium sorokinianum, Pyricularia oryzae, Fusarium oxysporum f. sp. vasinfectum, Fusarium oxysporum f. sp. cucumarinum and Alternaria brassicae. Compared to a commercial agricultural fungicide, hymexazol, especially compounds a, b, e, g and k were found to be more effective at 50 mug/ml against F. graminearum, F. oxysporum f. sp. vasinfectum and F. oxysporum f. sp. cucumarinum. Meantime, some structure-activity relationships were also observed. PMID:18057754

  17. 77 FR 39236 - Nanomaterial Case Study: A Comparison of Multiwalled Carbon Nanotubes and Decabromodiphenyl Ether...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... AGENCY Nanomaterial Case Study: A Comparison of Multiwalled Carbon Nanotubes and Decabromodiphenyl Ether... Study: A Comparison of Multiwalled Carbon Nanotubes and Decabromodiphenyl Ether Flame-Retardant Coatings... ``Nanomaterial Case Study: A Comparison of Multiwalled Carbon Nanotubes and Decabromodiphenyl Ether...

  18. Short and stereoselective total synthesis of furano lignans (+/-)-dihydrosesamin, (+/-)-lariciresinol dimethyl ether, (+/-)-acuminatin methyl ether, (+/-)-sanshodiol methyl ether, (+/-)-lariciresinol, (+/-)-acuminatin, and (+/-)-lariciresinol monomethyl ether and furofuran lignans (+/-)-sesamin, (+/-)-eudesmin, (+/-)-piperitol methyl ether, (+/-)-pinoresinol, (+/-)-piperitol, and (+/-)-pinoresinol monomethyl ether by radical cyclization of epoxides using a transition-metal radical source.

    PubMed

    Roy, Subhas Chandra; Rana, Kalyan Kumar; Guin, Chandrani

    2002-05-17

    Intramolecular radical cyclization of suitably substituted epoxy ethers 4a-g using bis(cyclopentadienyl)titanium(III) chloride as the radical source resulted in trisubstituted tetrahydrofurano lignans and 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane lignans depending on the reaction conditions. The titanium(III) species was prepared in situ from commercially available titanocene dichloride and activated zinc dust in THF. Upon radical cyclization followed by acidic workup, epoxy olefinic ethers 4a-g afforded furano lignans dihydrosesamin 1a, lariciresinol dimethyl ether 1b, acuminatin methyl ether 1e, and sanshodiol methyl ether 1g directly and lariciresinol 1h, acuminatin 1i, and lariciresinol monomethyl ether 1j after removal of the benzyl protecting group by controlled hydrogenolysis of the corresponding cyclized products. The furofuran lignans sesamin 2a, eudesmin 2b, and piperitol methyl ether 2e were also prepared directly by using the same precursors 4a-f on radical cyclization followed by treatment with iodine and pinoresinol 2h, piperitol 2i, and pinoresinol monomethyl ether 2j after controlled hydrogenolysis of the benzyl protecting group of the corresponding cyclized products. Two naturally occurring acyclic lignans, secoisolariciresinol 5h and secoisolariciresinol dimethyl ether 5b, have also been prepared by exhaustive hydrogenolysis of 2h and 2b, respectively.

  19. [Aerobic microbial degradation of polybrominated diphenyl ethers].

    PubMed

    Ding, Juan; Zhou, Juan; Jiang, Wei-Ying; Gao, Shi-Xiang

    2008-11-01

    The biodegradation of 4, 4'-dibromodipheny ether (BDE15) and decabromodiphenyl ether (BDE209) by white rot fungi under aerobic conditions was studied. Effects of non-ionic surfactant Tween 80 and beta-cyclodextrin as solubilizers on the apparent solubilities and biodegradation rates of BDE15 and BDE209 were also evaluated. The results showed that both BDE15 and BDE209 were efficiently degraded by white rot fungi. The degradation rates were 43.0% and 62.5% for BDE209 and BDE15, respectively, after 10 d incubation. The degradation of BDE209 was greatly enhanced by addition of Tween 80 (< or = 700 mg/L) and beta-cyclodextrin, which may own to their solubilization effects on BDE209. However, Tween 80 at a high concentration (900 mg/L) would restrain the fungal growth, thereby decrease the degradation of BDE209. Addition of Tween 80 and beta-cyclodextrin exhibited some negative effects on the degradation of BDE15, which may due to decreased concentration of free BDE15 in water solution resulted from inclusion function of Tween 80 micelles and beta-cyclodextrin cavity, although the apparent solubility of BDE15 was drastically increased by both of them. PMID:19186824

  20. Biosynthesis of archaeal membrane ether lipids

    PubMed Central

    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

  1. Imide/arylene ether copolymers with pendent trifluoromethyl groups

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J.; Havens, Stephen J.

    1992-01-01

    A series of imide/arylene ether block copolymers were prepared using an arylene ether block containing a hexafluoroisopropylidene group and an imide block containing a hexafluoroisopropylidene and a trifluoromethyl group in the polymer backbone. The copolymers were characterized and mechanical properties were determined and compared to the homopolymers.

  2. Process for producing dimethyl ether from synthesis gas

    DOEpatents

    Pierantozzi, R.

    1985-06-04

    This invention pertains to a Fischer Tropsch process for converting synthesis gas to an oxygenated hydrocarbon with particular emphasis on dimethyl ether. Synthesis gas comprising carbon monoxide and hydrogen are converted to dimethyl ether by carrying out the reaction in the presence of an alkali metal-manganese-iron carbonyl cluster incorporated onto a zirconia-alumina support.

  3. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  4. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  5. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  6. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  7. 40 CFR 721.3485 - Hydrofluorocarbon alkyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Hydrofluorocarbon alkyl ether. 721... Substances § 721.3485 Hydrofluorocarbon alkyl ether. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a hydrofluorocarbon alkyl...

  8. Responsive supramolecular gels constructed by crown ether based molecular recognition.

    PubMed

    Ge, Zhishen; Hu, Jinming; Huang, Feihe; Liu, Shiyong

    2009-01-01

    Responsive supramolecular gels were constructed from crown ether terminated four-arm star poly(epsilon-caprolactone) (PCL-DB24C8) and dibenzylammonium-terminated two-arm PCL-DBAS (see scheme), exploiting the formation of pseudorotaxane linkages between crown ether and ammonium moieties. The resultant supramolecular gels exhibit thermo- and pH-induced reversible gel-sol transition.

  9. Preparation of highly fluorinated diols containing ether linkages.

    NASA Technical Reports Server (NTRS)

    Rochow, S. E.; Stump, E. C., Jr.

    1970-01-01

    Hydroxy-terminated perfluoroethers and polyurethane resins derived from ethers have outstanding chemical resistance and good thermal properties. They can be used as potting compounds, coatings, and seals. The hydroxy-terminated ethers serve as intermediates in the synthesis of highly fluorinated elastomers and adhesives.

  10. IRIS Toxicological Review of Decabromodiphenyl Ether (2008 Final)

    EPA Science Inventory

    EPA is announcing the release of the final report, Toxicological Review of Decabromodiphenyl Ether: in support of the Integrated Risk Information System (IRIS). The updated Summary for Decabromodiphenyl Ether and accompanying Quickview have also been added to the IRIS Data...

  11. 47. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, 4TH LEVEL, LOOKING NORTH AT TOPS OF ALCOHOL AND ETHER DISTILLATION TOWERS. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  12. 48. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    48. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, 5TH LEVEL, LOOKING NORTH AT ETHER AND ALCOHOL CONDENSERS AT TOP OF TOWER. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  13. 46. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, CONTROL PANEL LEVEL (2ND DECK) OF ETHER AND ALCOHOL STILL BUILDING, LOOKING NORTH, SHOWING TWO ALCOHOL DISTILLATION TOWERS BEHIND 'MIXED SOLVENT UNIT' CONTROL PANEL. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  14. 29 CFR 1926.1106 - Methyl chloromethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Methyl chloromethyl ether. 1926.1106 Section 1926.1106 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... § 1926.1106 Methyl chloromethyl ether. Note: The requirements applicable to construction work under...

  15. 29 CFR 1915.1006 - Methyl chloromethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Methyl chloromethyl ether. 1915.1006 Section 1915.1006 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Hazardous Substances § 1915.1006 Methyl chloromethyl ether. Note: The requirements applicable to...

  16. 29 CFR 1926.1106 - Methyl chloromethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Methyl chloromethyl ether. 1926.1106 Section 1926.1106 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... § 1926.1106 Methyl chloromethyl ether. Note: The requirements applicable to construction work under...

  17. 29 CFR 1910.1006 - Methyl chloromethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 6 2010-07-01 2010-07-01 false Methyl chloromethyl ether. 1910.1006 Section 1910.1006 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Substances § 1910.1006 Methyl chloromethyl ether. See § 1910.1003, 13 carcinogens....

  18. 29 CFR 1910.1006 - Methyl chloromethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 6 2011-07-01 2011-07-01 false Methyl chloromethyl ether. 1910.1006 Section 1910.1006 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Substances § 1910.1006 Methyl chloromethyl ether. See § 1910.1003, 13 carcinogens....

  19. 29 CFR 1910.1008 - bis-Chloromethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 6 2011-07-01 2011-07-01 false bis-Chloromethyl ether. 1910.1008 Section 1910.1008 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... bis-Chloromethyl ether. See § 1910.1003, 13 carcinogens....

  20. 29 CFR 1910.1008 - bis-Chloromethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 6 2010-07-01 2010-07-01 false bis-Chloromethyl ether. 1910.1008 Section 1910.1008 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... bis-Chloromethyl ether. See § 1910.1003, 13 carcinogens....

  1. 29 CFR 1915.1008 - bis-Chloromethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false bis-Chloromethyl ether. 1915.1008 Section 1915.1008 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1008 bis-Chloromethyl ether. Note: The requirements applicable to shipyard employment under...

  2. 29 CFR 1915.1006 - Methyl chloromethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Methyl chloromethyl ether. 1915.1006 Section 1915.1006 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Hazardous Substances § 1915.1006 Methyl chloromethyl ether. Note: The requirements applicable to...

  3. 40 CFR 721.825 - Certain aromatic ether diamines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Certain aromatic ether diamines. 721.825 Section 721.825 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC... Substances § 721.825 Certain aromatic ether diamines. (a) Chemical substances and significant new...

  4. 29 CFR 1915.1008 - bis-Chloromethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false bis-Chloromethyl ether. 1915.1008 Section 1915.1008 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1008 bis-Chloromethyl ether. Note: The requirements applicable to shipyard employment under...

  5. 29 CFR 1926.1108 - bis-Chloromethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false bis-Chloromethyl ether. 1926.1108 Section 1926.1108 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...-Chloromethyl ether. Note: The requirements applicable to construction work under this section are identical...

  6. 29 CFR 1926.1108 - bis-Chloromethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false bis-Chloromethyl ether. 1926.1108 Section 1926.1108 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...-Chloromethyl ether. Note: The requirements applicable to construction work under this section are identical...

  7. The Ether Wind and the Global Positioning System.

    ERIC Educational Resources Information Center

    Muller, Rainer

    2000-01-01

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

  8. 40 CFR 721.825 - Certain aromatic ether diamines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Certain aromatic ether diamines. 721... Substances § 721.825 Certain aromatic ether diamines. (a) Chemical substances and significant new uses...,5-benzenetetracarboxylic acid, diethyl ester, compound with 4,4′- -2,5-diylbis(oxy)]bis (1:1) (PMN...

  9. Process for producing dimethyl ether form synthesis gas

    DOEpatents

    Pierantozzi, Ronald

    1985-01-01

    This invention pertains to a Fischer Tropsch process for converting synthesis gas to an oxygenated hydrocarbon with particular emphasis on dimethyl ether. Synthesis gas comprising carbon monoxide and hydrogen are converted to dimethyl ether by carrying out the reaction in the presence of an alkali metal-manganese-iron carbonyl cluster incorporated onto a zirconia-alumina support.

  10. The Knock-Limited Performance of Fuel Blends Containing Aromatics V : N-Propylbenzene, N-Butylbenzene, Isobutylbenzene, M-Xylene, and 1-Isopropyl-4-Methylbenzene

    NASA Technical Reports Server (NTRS)

    Meyer, Carl L.; Branstetter, J. Robert

    1946-01-01

    Results are reported of knock-limited tests of five aromatics, each individually blended with selected base fuels and tested with and without TEL, using 17.6, F-4, and F-3 small-scale engines. The five aromatics rated in the following order of decreasing antiknock effectiveness at fuel/air ratio 0.10: m-xylene, 1-isopropyl-4-methylbenzene, n-propylbenzene, isobutylbenzene, and n-butylbenzene.

  11. Relationship of the eye uptake of N-isopropyl-p-(/sup 123/I)iodoamphetamine to melanin production

    SciTech Connect

    Holman, B.L.; Wick, M.M.; Kaplan, M.L.; Hill, T.C.; Lee, R.G.L.; Wu, J.; Lin, T.H.

    1984-03-01

    Eye uptake has been a potential concern with N-isopropyl-p-(/sup 123/I)iodoamphetamine (I-123 IMP) because it has been observed in certain animal species. The authors have investigated the cause of the eye uptake and its relationship to melanin synthesis. In a 1-yr-old cynomolgus monkey, high concentration of the tracer was seen in the eyes regardless of the type of anesthesia (pentobarbital or ketamine) or the oral administration of Lugol's solution. The eye uptake at 24 hr after injection of I-123 IMP was equally high in an 8-yr-old rhesus monkey. The ratio of radioactivity in the eye of black compared with white albino mice was 10:1 at 30 min, 18:1 at 2 hr and 36:1 at 24 hr after injection if I-123 IMP. No eye uptake above soft-tissue background was seen in five patients at 2, 24, and 48 hr after injection. I-123 IMP is avidly incorporated into melanocytes actively producing melanin, but substantially less in melanocytes where production of melanin has ceased as in the human eye.

  12. Hydrophobic hydration of poly-N-isopropyl acrylamide: a matter of the mean energetic state of water

    NASA Astrophysics Data System (ADS)

    Bischofberger, I.; Calzolari, D. C. E.; de Los Rios, P.; Jelezarov, I.; Trappe, V.

    2014-03-01

    The enthalpically favoured hydration of hydrophobic entities, termed hydrophobic hydration, impacts the phase behaviour of numerous amphiphiles in water. Here, we show experimental evidence that hydrophobic hydration is strongly determined by the mean energetics of the aqueous medium. We investigate the aggregation and collapse of an amphiphilic polymer, poly-N-isopropyl acrylamide (PNiPAM), in aqueous solutions containing small amounts of alcohol and find that the thermodynamic characteristics defining the phase transitions of PNiPAM evolve relative to the solvent composition at which the excess mixing enthalpy of the water/alcohol mixtures becomes minimal. Such correlation between solvent energetics and solution thermodynamics extends to other mixtures containing neutral organic solutes that are considered as kosmotropes to induce a strengthening of the hydrogen bonded water network. This denotes the energetics of water as a key parameter controlling the phase behaviour of PNiPAM and identifies the excess mixing enthalpy of water/kosmotrope mixtures as a gauge of the kosmotropic effect on hydrophobic assemblies.

  13. Breath gas concentrations mirror exposure to sevoflurane and isopropyl alcohol in hospital environments in non-occupational conditions.

    PubMed

    Castellanos, Mar; Xifra, Gemma; Fernández-Real, José Manuel; Sánchez, Juan M

    2016-03-01

    Anaesthetic gases and disinfectants are a primary source of air contamination in hospitals. A highly sensitive sorbent-trap methodology has been used to analyse exhaled breath samples with detection limits in the pptv range, which allows volatile organic compounds (VOCs) to be detected at significantly lower levels (5-6 orders of magnitude below) than the recommended exposure limits by different organizations. Two common VOCs used in hospital environments, isopropyl alcohol (IPA) and sevoflurane, have been evaluated. Forced-expiratory breath samples were obtained from 100 volunteers (24 hospital staff, 45 hospital visitors and 31 external controls). Significant differences for IPA were found between samples from volunteers who had not been in contact with hospital environments (mean value of 8.032 ppbv) and people staying (20.981 ppbv, p  =  0.0002) or working (19.457 ppbv, p  =  0.000 09) in such an environment. Sevoflurane, an anaesthetic gas routinely used as an inhaled anaesthetic, was detected in all samples from volunteers in the hospital environment but not in volunteers who had not been in recent contact with a hospital environment. The levels of sevoflurane were significantly higher (p  =  0.000 24) among staff members (0.522 ppbv) than among visitors to the hospital (0.196 ppbv). We conclude that highly sensitive methods are required to detect anaesthetic gas contamination in hospital environments. PMID:26824193

  14. Superficially porous particles vs. fully porous particles for bonded high performance liquid chromatographic chiral stationary phases: isopropyl cyclofructan 6.

    PubMed

    Spudeit, Daniel A; Dolzan, Maressa D; Breitbach, Zachary S; Barber, William E; Micke, Gustavo A; Armstrong, Daniel W

    2014-10-10

    This work reports a comparison of HPLC separations of enantiomers with chiral stationary phases (CSPs) prepared by chemically bonding cyclofructan-6, functionalized with isopropyl carbamate groups on fully and superficially porous particles (SPPs). The chromatographic performance of the superficially porous CSP based column was compared with columns packed with 5 μm and 3 μm fully porous particles (FPPs). At a flow rate of 3.0 mL/min the number of plates on column afforded by the SPP column was ∼7× greater than the number of plates on column (same length) obtained when using the 5 μm FPP based column. The flow rate providing the highest efficiency separation was ∼1.0 mL/min for the SPP column while it was ∼0.5 mL/min for both FPP columns. It was found that the selectivity and resolution of the separations were comparable between fully porous and superficially porous based columns (under constant mobile phase conditions), even though the SPP column contained lower absolute amounts of chiral selector. When tested under constant retention conditions, the SPP based CSP greatly improved resolution compared to the FPP based columns. At high flow rates the efficiency gained by using superficially porous CSP was accentuated. The advantages of columns based on SPPs become more obvious from the viewpoint of plate numbers and resolution per analysis time.

  15. Breath gas concentrations mirror exposure to sevoflurane and isopropyl alcohol in hospital environments in non-occupational conditions.

    PubMed

    Castellanos, Mar; Xifra, Gemma; Fernández-Real, José Manuel; Sánchez, Juan M

    2016-01-29

    Anaesthetic gases and disinfectants are a primary source of air contamination in hospitals. A highly sensitive sorbent-trap methodology has been used to analyse exhaled breath samples with detection limits in the pptv range, which allows volatile organic compounds (VOCs) to be detected at significantly lower levels (5-6 orders of magnitude below) than the recommended exposure limits by different organizations. Two common VOCs used in hospital environments, isopropyl alcohol (IPA) and sevoflurane, have been evaluated. Forced-expiratory breath samples were obtained from 100 volunteers (24 hospital staff, 45 hospital visitors and 31 external controls). Significant differences for IPA were found between samples from volunteers who had not been in contact with hospital environments (mean value of 8.032 ppbv) and people staying (20.981 ppbv, p  =  0.0002) or working (19.457 ppbv, p  =  0.000 09) in such an environment. Sevoflurane, an anaesthetic gas routinely used as an inhaled anaesthetic, was detected in all samples from volunteers in the hospital environment but not in volunteers who had not been in recent contact with a hospital environment. The levels of sevoflurane were significantly higher (p  =  0.000 24) among staff members (0.522 ppbv) than among visitors to the hospital (0.196 ppbv). We conclude that highly sensitive methods are required to detect anaesthetic gas contamination in hospital environments.

  16. Isopropyl­aminium 2-carb­oxy-4,5-di­chloro­benzoate

    PubMed Central

    Smith, Graham; Wermuth, Urs D.

    2010-01-01

    In the structure of the 1:1 proton-transfer compound of isopropyl­amine with 4,5-dichloro­phthalic acid, C3H10N+·C8H3Cl2O4 −, the three cation H-atom donors associate with three separate carboxyl O-atom anion acceptors, giving conjoint cyclic R 4 4(12), R 4 4(16) hydrogen-bonding cation–anion inter­actions in a one-dimensional ribbon structure. In the anions, the carboxyl groups lie slightly out of the plane of the benzene ring [maximum deviations = 0.439 (1) for a carboxylic acid O atom and 0.433 (1) Å for a carboxyl­ate O atom]. However, the syn-related proton of the carboxylic acid group forms the common short intra­molecular O—H⋯Ocarbox­yl hydrogen bond. PMID:21580024

  17. Synthesis and evaluation of 24-(isopropyl(75Se)seleno)chol-5-en-3 beta-ol

    SciTech Connect

    Knapp, F.F. Jr.; Butler, T.A.; Ferren, L.A.; Callahan, A.P.; Guyer, C.E.; Coffey, J.L.

    1983-10-01

    Selenium-75-labeled 24-(isopropylseleno)chol-5-en-3 beta-ol (4) has been prepared by reaction of sodium isopropyl-(75Se)selenol (( 75Se)2) with 3 beta-acetoxy-24-bromochol-5-ene (3). This new 75Se-labeled adrenal imaging agent shows pronounced adrenal uptake in rats. The concentration of radioactivity in rat adrenals increased steadily from 1 to 24 h after injection and then decreased slowly over the 21-day period. After 3 days the adrenal/blood and adrenal/liver ratios were 85:1 and 32:1, respectively, which are sufficient for adrenal imaging by single photon techniques. After 6 h the adrenal/blood ratio was 17:1 and the adrenal/liver ratio was 7:1. We propose that these ratios are sufficiently high for positron emission tomography of the adrenals. The absorbed radiation dose values to human organs have been estimated for the 75Se- and 73Se-labeled agent.

  18. Selective synthesis and device applications of semiconducting single-walled carbon nanotubes using isopropyl alcohol as feedstock.

    PubMed

    Che, Yuchi; Wang, Chuan; Liu, Jia; Liu, Bilu; Lin, Xue; Parker, Jason; Beasley, Cara; Wong, H-S Philip; Zhou, Chongwu

    2012-08-28

    The development of guided chemical vapor deposition (CVD) growth of single-walled carbon nanotubes provides a great platform for wafer-scale integration of aligned nanotubes into circuits and functional electronic systems. However, the coexistence of metallic and semiconducting nanotubes is still a major obstacle for the development of carbon-nanotube-based nanoelectronics. To address this problem, we have developed a method to obtain predominantly semiconducting nanotubes from direct CVD growth. By using isopropyl alcohol (IPA) as the carbon feedstock, a semiconducting nanotube purity of above 90% is achieved, which is unambiguously confirmed by both electrical and micro-Raman measurements. Mass spectrometric study was performed to elucidate the underlying chemical mechanism. Furthermore, high performance thin-film transistors with an on/off ratio above 10(4) and mobility up to 116 cm(2)/(V·s) have been achieved using the IPA-synthesized nanotube networks grown on silicon substrate. The method reported in this contribution is easy to operate and the results are highly reproducible. Therefore, such semiconducting predominated single-walled carbon nanotubes could serve as an important building block for future practical and scalable carbon nanotube electronics.

  19. Transplacental effects of 3,5-dimethyl-3'-isopropyl-L-thyronine on fetal hypothyroidism in primates

    SciTech Connect

    Bachrach, L.K.; Dibattista, D.; Burrow, G.N.; Holland, F.J.

    1983-06-01

    Pregnant Rhesus monkeys treated with 131I at midgestation become hypothyroid and produce fetuses without demonstrable thyroid tissue. In an effort to prevent both maternal and fetal hypothyroidism, we treated 131I-treated pregnant monkeys with 3,5-dimethyl-3'-isopropyl-L-thyronine (DIMIT), a thyroid hormone analog with structural changes which facilitate placental transfer. Five pregnant monkeys were treated with 131I (mCi/kg) at 83-87 days of gestation. One week later, three monkeys were started on treatment with DIMIT (10 micrograms kg-1 day-1, im) and two on im L-T4 (2 micrograms kg-1 day-1). Treatment was continued until delivery by Caesarian section at 152-157 days of gestation. None of the DIMIT-treated mothers became clinically hypothyroid, nor did they have elevated serum TSH concentrations despite low serum levels of T3 and T4. T4-treated mothers were also maintained clinically and biochemically euthyroid. At delivery, infants of DIMIT-treated mothers had normal respiratory function and skeletal maturation. Basal and TRH-stimulated TSH concentrations were suppressed in two of the three infants. By contrast, both T4-treated infants resembled untreated cretinous newborns and died soon after delivery from respiratory failure. Serum TSH concentrations were elevated and skeletal maturation was markedly delayed in these animals. We conclude that DIMIT administration to 131I-treated monkeys prevents clinical and biochemical hypothyroidism in the mother and prevents the major clinical manifestations of cretinism in the fetus.

  20. Blood-brain barrier transport of butanol and water relative to N-isopropyl-p-iodoamphetamine as the internal reference

    SciTech Connect

    Pardridge, W.M.; Fierer, G.

    1985-06-01

    The literature regarding the blood--brain barrier (BBB) transport of butanol is conflicting as studies report both incomplete and complete extraction of butanol by the brain. In this work the BBB transport of both (/sup 14/C)butanol and (/sup 3/H)water was studied using the carotid injection technique in conscious and in ketamine- or pentobarbital-anesthetized rats employing N-isopropyl-p-(/sup 125/I)iodoamphetamine ((/sup 125/I)IMP) as the internal reference and as a fluid microsphere. The three isotopes (/sup 3/H, /sup 125/I, /sup 14/C) were conveniently counted simultaneously in a liquid scintillation spectrometer. IMP is essentially completely sequestered by the brain for at least 1 min in conscious rats and for 2 min in anesthetized animals. Butanol extraction by rat forebrain is not flow limited but ranges between 77 +/- 1 and 87 +/- 1% for the three conditions. The permeability-surface area product/cerebral blood flow ratio of butanol and water in rat forebrain remains relatively constant, despite a twofold increase in cerebral blood flow in conscious relative to pentobarbital-anesthetized rats. The absence of an inverse relationship between flow and butanol or water extraction is consistent with capillary recruitment being the principal mechanism underlying changes in cerebral blood flow in anesthesia. The diffusion restriction of BBB transport of butanol in some regions, but not in others, necessitates a careful regional analysis of BBB permeability to butanol prior to usage of this compound as a cerebral blood flow marker.

  1. The sarin-like organophosphorus agent bis(isopropyl methyl)phosphonate induces ER stress in human astrocytoma cells.

    PubMed

    Arima, Yosuke; Shiraishi, Hiroaki; Saito, Atsushi; Yoshimoto, Kanji; Namera, Akira; Makita, Ryosuke; Murata, Kazuhiro; Imaizumi, Kazunori; Nagao, Masataka

    2016-01-01

    Organophosphorus (OP) compounds such as sarin are toxic agents that irreversibly inhibit the enzyme acetylcholinesterase. A recent study showed that OP compounds also have multiple toxicity mechanisms, and another suggested that endoplasmic reticulum (ER) dysfunction contributes to OP toxicity. However, the signaling pathway and mechanisms involved are poorly understood. We examined whether the sarin-like OP agent bis(isopropyl methyl)phosphonate (BIMP), which exhibits toxicity similar to that of sarin, induced ER stress in human astrocytoma CCF-STTG1 cells. Our results demonstrate that BIMP exposure reduced cell viability. Moreover, it induced changes in mitochondrial membrane potential and increased cleavage of caspase 3. Treatment with BIMP increased the mRNA levels of the ER stress marker genes binding immunoglobulin protein (BiP) and the transcription factor C/EBP homologous protein (CHOP). Furthermore, BIMP increased the protein expressions and phosphorylation of BiP, CHOP, and protein kinase RNA-like ER kinase and the phosphorylation of eukaryotic translation initiation factor 2. Compared to BIMP treatment alone, pretreatment with the CHOP siRNA, siCHOP, decreased BIMP-dependent CHOP expression and improved CCF-STTG1 cell viability. Our findings suggest that BIMP induced mitochondrial dysfunction and apoptotic cell death event mediated by ER stress in CCF-STTG1 cells and that treatment targeted at managing ER stress has the potential to attenuate the toxicity of OP nerve agents. PMID:27665771

  2. Sustained release pellets based on poly(N-isopropyl acrylamide): matrix and in situ photopolymerization-coated systems.

    PubMed

    Mayo-Pedrosa, Marcos; Alvarez-Lorenzo, Carmen; Lacík, Igor; Martinez-Pacheco, Ramon; Concheiro, Angel

    2007-01-01

    The usefulness of poly(N-isopropyl acrylamide), PNIPA, for preparing sustained release matrix or photopolymerization-coated cellulosic pellets was evaluated. Theophylline pellets and granules were prepared using powdered cellulose (PC), poly(vinylpyrrolidone) (PVP), and PNIPA of Mw approximately 330 kDa, Mn approximately 93 kDa and low critical solubility temperature approximately 32 degrees C. The low consistency of wet mass, evaluated by torsion rheometry, due to hydrophilic character of PNIPA at room temperature, favored extrusion-spheronization. Theophylline (20%) pellets prepared with 15% PNIPA, 20% PVP and 45% PC, and granules obtained using 40% PNIPA and 40% PC showed an enhanced, although limited, ability to sustain the release. This effect was notably promoted after compression (which provides slowly eroding tablets) or coating of individualized pellets. A new coating technique consisting in forming the polymer film by photo-polymerization/cross-linking of NIPA monomers on pellets surface, using a photoinitiator and UV-irradiation at 366 nm, was developed. The composition of coating mixture and the time of irradiation were optimized using oscillatory rheometry. Coating did not significantly change the shape, size, or friability of the pellets but remarkably decreased the porosity and sustained drug release for several hours. In situ formation and cross-linking of PNIPA on the pellet appears as a feasible way for controlling drug release. PMID:16967440

  3. Quantitative temporal analysis of /sup 99m/Technetium p-isopropyl-iminodiacetic acid (PIPIDA) as a measure of hepatic function in health and disease

    SciTech Connect

    Joshi, S.N.; George, E.A.; Perrillo, R.P.

    1981-01-01

    Excretory liver function was analyzed in 10 healthy volunteers and 28 subjects with acute or chronic liver injury following intravenous administration of /sup 99m/technetium p-isopropyl iminodiacetic acid. Hepatobiliary transit of this agent was quantitated at 5-min intervals for a total of 60 min. Indices of total liver activity, liver cell uptake, liver parenchymal clearance, and bile duct clearance of /sup 99m/technetium p-isopropyl iminodiacetic acid were calculated from time--activity curves over heart, liver, extrahepatic bile ducts, and gallbladder. Seven subjects with acute viral hepatitis, 15 with extrahepatic biliary obstruction, and 6 with intrahepatic cholestasis were evaluated. Compared with healthy volunteers, a significant (p less than 0.0001) reduction in total liver activity and liver parenchymal clearance was demonstrated in all patient groups. Major resolution in all liver-derived indices, particularly total liver activity, occurred during convalescence from hepatitis and after biliary drainage. Nonmeasurable bile duct clearance always indicated a diagnosis of extrahepatic obstruction in cholestatic subjects, and this index normalized in subjects following biliary drainage. Whereas visual assessment of /sup 99m/technetium p-isopropyl iminodiacetic acid scans provided limited, useful information about the functional status of the liver, quantitative temporal analysis proved to be a much more effective technique.

  4. [Recent development of research on the biotribology of carbon fiber reinforced poly ether ether ketone composites].

    PubMed

    Chen, Yan; Pan, Yusong

    2014-12-01

    Carbon fiber reinforced poly ether ether ketone (CF/PEEK) composite possesses excellent biocompatible, biomechanical and bioribological properties. It is one of the most promising implant materials for artificial joint. Many factors influence the bioribological properties of CF/PEEK composites. In this paper, the authors reviewed on the biotribology research progress of CF/PEEK composites. The influences of various factors such as lubricant, reinforcement surface modification, functional particles, friction counterpart and friction motion modes on the bio-tribological properties of CF/PEEK composites are discussed. Based on the recent research, the authors suggest that the further research should be focused on the synergistic effect of multiple factors on the wear and lubrication mechanism of CF/PEEK. PMID:25868268

  5. A sulfonated poly (aryl ether ether ketone ketone) isomer: synthesis and DMFC performance

    SciTech Connect

    Kim, Yu Seung; Liu, Baijun; Hu, Wei; Jiang, Zhenhua; Robertson, Gilles; Guiver, Michael

    2009-01-01

    A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily-prepared PEEKK post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported analogues and eveluated Nafion membranes.

  6. The effect of high-energy electron radiation on poly(arylene ether)s

    NASA Technical Reports Server (NTRS)

    Connell, J. W.; Siochi, E. J.; Croall, C. I.

    1993-01-01

    Thin films of four experimental poly(arylene ether)s of similar chemical structure were exposed to 1 MeV electrons while under high vacuum. The films received total exposures of 5 x 10 exp 7 and 1 x 10 exp 9 rads at a dose rate of 5 x 10 exp 7 rads/h and a pressure of 2 x 10 exp -7 torr. Films exposed to 5 x 10 exp 7 rads showed dramatic changes in molecular weight distribution. After exposures of 1 x 10 exp 9 rads the films were only partially soluble in chloroform and exhibited no detectable changes in the glass transition temperatures. Thin-film tensile properties were also altered by the exposure to electron radiation. The effect of the exposures as determined by various analyses is discussed.

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

    SciTech Connect

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

    2014-06-21

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

  8. Methoxy-ether and crown-ether derivatives of tetrahomodioxa- and octahomotetraoxacalix[4]arenes.

    PubMed

    Masci, B; Saccheo, S; Fonsi, M; Varrone, M; Finelli, M; Nierlich, M; Thuéry, P

    2001-08-01

    Three methoxy-ether and one methoxy-ether/crown-ether derivatives of p-tert-butyltetrahomodioxa- and p-R-octahomotetraoxacalix[4]arenes (R = methyl, tert-butyl, H) have been investigated. The first three compounds, 7,15,21,27-tetra-tert-butyl-29,30,31,32-tetramethoxy-3,11-dioxapentacyclo[23.3.1.1(5,9).1(13,17).1(19,23)]ditriaconta-1(29),5,7,9(30),13,15,-17(31),19,21,23(32),25,27-dodecaene, C(50)H(68)O(6), 33,34,35,36-tetramethoxy-7,15,23,31-tetramethyl-3,11,19,27-tetraoxapentacyclo[27.3.1.1(5,9).1(13,17).1(21,25)]hexatriaconta-1(33),5,7,9(34),13,15,17(35),21,23,25(36),29,31-dodecaene, C(40)H(48)O(8), and 7,23-di-tert-butyl-33,34,35,36-tetramethoxy-3,11,19,27-tetraoxapentacyclo[27.3.1.1(5,9).1(13,17).1(21,25)]hexatriaconta-1(33),5,7,9(34),13,15,17(35),- 21,23,25(36),29,31-dodecaene, C(44)H(56)O(8), in the partial-cone or 1,2-alternate conformations, present the common feature of methoxy-ether self-inclusion, while the fourth, 42,43-dimethoxy-7,15,23,31-tetramethyl-3,11,19,27,34,37,40-heptaoxahexacyclo[15.15.9.1(5,9).1(21,25).0(13,41).0(29,33)]tritetraconta-5(42),6,8,13(41),14,16,21(43),22,24,29(33),30,32-dodecaene, C(42)H(50)O(9), adopts the 1,3-alternate conformation owing to the presence of a 1,3-polyether chain.

  9. Development of specialty chemicals from dimethyl ether

    SciTech Connect

    Tartamella, T.L.; Lee, S.

    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.

  10. High temperature fuel cell membranes based on poly(arylene ether)s containing benzimidazole groups

    SciTech Connect

    Kim, Dae Sik; Kim, Yu Seung; Lee, Kwan - Soo; Boncella, James M; Kuiper, David; Guiver, Michael D

    2009-01-01

    Development of new high-performance polymer membranes that retain their proton conductivity under low humidity conditions is one of the most critical requirements to commercialize PEMFC systems. Current sulfonated proton exchange membranes acquire proton conductivity by water that solvates ion and carries proton. Consequently, a loss of water under low RH conditions immediately results in a loss of proton conductivity. One approach to maintain proton conductivity under low RH conditions is to replace water with a less volatile proton solvent. Kreuer has pointed out the possibility to develop fully polymeric proton-conducting membranes based on nitrogen-containing heterocycles such as imidazole, benzimidazole, and pyrazole. We have attempted to blend those less volatile proton solvent with sulfonated copolymers such as polystyrene sulfonic acid, Nafion, poly(arylene ether sulfone, BPSH-xx). [Ref. DOE review meeting 2007 and 2008] However, we observed that imidazole was slowly sublimated out as temperature and humidity increases which could cause poisoning of electro-catalyst, corrosion and losing conductivity. In this presentation, we report the synthesis of novel poly(arylene ether sulfone)s containing benzimidazole groups These benzimidazole containing polymer was blended with sulfonated poly(arylene ether sulfone). In the blend system, benzimidazole group attached to the polysulfone acts as a medium through the basic nitrogen for transfer of protons between the sulfonic acid groups. Proton conductivity of the blend membranes was investigated as a function of water content at 80 C and compared the performance with water based proton conduction system.

  11. Formulating liquid ethers for microtubular SOFCs

    NASA Astrophysics Data System (ADS)

    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.

  12. Crown Ethers in Nonaqueous Electrolytes for Lithium/Air Batteries

    SciTech Connect

    Xu, Wu; Xiao, Jie; Wang, Deyu; Zhang, Jian; Zhang, Jiguang

    2010-02-04

    The effects of three crown ethers, 12-crown-4, 15-crown-5, and 18-crown-6, as additives and co-solvents in non-aqueous electrolytes on the cell performance of primary Li/air batteries operated in a dry air environment were investigated. Crown ethers have large effects on the discharge performance of non-aqueous electrolytes in Li/air batteries. A small amount (normally less than 10% by weight or volume in electrolytes) of 12-Crown-4 and 15-crown-5 reduces the battery performance and a minimum discharge capacity appears at the crown ether content of ca. 5% in the electrolytes. However, when the content increases to about 15%, both crown ethers improve the capacity of Li/air cells by about 28% and 16%, respectively. 15-Crown-5 based electrolytes even show a maximum discharge capacity in the crown ether content range from 10% to 15%. On the other hand, the increase of 18-crown-6 amount in the electrolytes continuously lowers of the cell performance. The different battery performances of these three crown ethers in electrolytes are explained by the combined effects from the electrolytes’ contact angle, oxygen solubility, viscosity, ionic conductivity, and the stability of complexes formed between crown ether molecules and lithium ions.

  13. Characterization of Microsolvated Crown Ethers from Broadband Rotational Spectroscopy

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  14. The synthesis of nonlinear optical (NLO) poly(hydroxy ethers)

    SciTech Connect

    Brennan, D.J.; Gulotty, R.J.; Inbasekaran, M.

    1995-12-31

    New poly(hydroxy ethers) have been prepared which exhibit an excellent combination of (a) high second-order nonlinear optical (NLO) activity (d{sub 33} of 20-28 x 10{sup -9} esu, 1064 nm, after parallel plate poling at E=0.5 MV/cm), (b) high glass transition temperatures Tg=150-200{degrees}C, (c) persistence of activity at 100{degrees}C, and (d) excellent processability. The NLO poly(hydroxy ethers) are prepared by the reactions of aromatic diglycidyl ethers with bisphenols that contain dipolar moieties based on nitrophenylhydrazones and other chromophores.

  15. Synthesis and biological activity of gem-dichlorocyclopropyl ethers

    SciTech Connect

    Shostakovskii, S.M.; Mochalov, V.N.; Larionov, G.M.

    1986-09-01

    In order to examine the antimicrobial activity of oxygenated cyclopropanes, the authors have synthesized the bis-gem-dichlorocyclopropyl ether of ethylene glycol, the meso- and dl- forms of bis-gem-dichlorocyclopropyl ether, and the gem-dichlorocyclopropyl alkyl ethers. The physiocochemical properties of compounds obtained are presented. The authors conclude that in the case of gem-dichlorocyclopropane compounds, decontamination of microorganisms occurs at the pre-metabolic stage, and results in the denaturation of the protein components of the cell wall and external membranes and of the specific peptides of the peptide-glycan layer.

  16. From globules to crystals: a spectral study of poly(2-isopropyl-2-oxazoline) crystallization in hot water.

    PubMed

    Sun, Shengtong; Wu, Peiyi

    2015-12-28

    One easy strategy to comprehend the complex folding/crystallization behaviors of proteins is to study the self-assembly process of their synthetic polymeric analogues with similar properties owing to their simple structures and easy access to molecular design. Poly(2-isopropyl-2-oxazoline) (PIPOZ) is often regarded as an ideal pseudopeptide with similar two-step crystallization behavior to proteins, whose aqueous solution experiences successive lower critical solution temperature (LCST)-type liquid-liquid phase separation upon heating and irreversible crystallization when annealed above LCST for several hours. In this paper, by microscopic observations, IR and Raman spectroscopy in combination with 2D correlation analysis, we show that the second step of PIPOZ crystallization in hot water can be further divided into two apparent stages, i.e., nucleation and crystal growth, and perfect crystalline PIPOZ chains are found to only develop in the second stage. While all the groups exhibit changes in initial nucleation, only methylene groups on the backbone participate in the crystal growth stage. During nucleation, a group motion transfer is found from the side chain to the backbone, and nucleation is assumed to be mainly driven by the cleavage of bridging C=O···D-O-D···O=C hydrogen bonds followed by chain arrangement due to amide dipolar orientation. Nevertheless, during crystal growth, a further chain ordering process occurs resulting in the final formation of crystalline PIPOZ chains with partial trans conformation of backbones and alternative side chains on the two sides. The underlying crystallization mechanism of PIPOZ in hot water we present here may provide very useful information for understanding the crystallization of biomacromolecules in biological systems.

  17. Increased diazinon hydrolysis to 2-isopropyl-6-methyl-4-pyrimidinol in liquid medium by a specific Streptomyces mixed culture.

    PubMed

    Briceño, G; Schalchli, H; Rubilar, O; Tortella, G R; Mutis, A; Benimeli, C S; Palma, G; Diez, M C

    2016-08-01

    Actinobacteria identified as Streptomyces spp. were evaluated for their ability to remove diazinon as the only carbon source from a liquid medium. Single cultures of Streptomyces strains were exposed to diazinon at a concentration of 50 mg L(-1). After 96 h incubation, six of the eight cultures grew and five strains showed an increase in their total protein concentrations and changes in their protein profile. Up to 32% of the diazinon was removed by the single Streptomyces cultures. A compatibility assay showed that the different Streptomyces species were not antagonistic. Twenty-six mixed cultures were then prepared. Diazinon removal was increased when mixed cultures were used, and maximum diazinon removal of 62% was observed when the Streptomyces spp. strains AC5, AC9, GA11 and ISP13 were mixed; this was defined as the selected mixed culture (SMC). Diazinon removal was positively influenced by the addition of glucose into the liquid medium. Our study showed a diazinon degradation rate of 0.025 h(-1), half-life of 28 h(-1) and 2-isopropyl-6-methyl-4-pyrimidinol (IMHP) production of 0.143 mg L h(-1). Rapid diazinon hydrolysis to IMHP was associated with a decrease in the pH of the medium as a consequence of microbial glucose metabolism and organic acid exudation. Moreover, the SMC of Streptomyces was able to remove IMHP. This work constitutes a new, if not the only, report on diazinon degradation by mixed cultures of Streptomyces spp. Given the high levels of diazinon removal, the SMC formed by four Streptomyces strains has the potential to be used to treat the diazinon present in environmental matrices. PMID:27176942

  18. Mechanical and swelling characterization of poly(N-isopropyl acrylamide -co- methoxy poly(ethylene glycol) methacrylate) sol-gels.

    PubMed

    Pollock, Jacob F; Healy, Kevin E

    2010-04-01

    The dimensional stability and rheological properties of a series of comb-like copolymers of N-isopropyl acrylamide (NIPAAm) and methoxy poly(ethylene glycol) methacrylate (mPEGMA), poly(NIPAAm-co-mPEGMA), with varying poly(ethylene glycol) (PEG) graft densities and molecular weights were studied. The thermoresponsive character of the copolymer solutions was investigated by kinetic and equilibrium swelling, as well as by static and dynamic mechanical analysis. Surface response mapping was employed to target particular compositions and concentrations with excellent dimensional stability and a relatively large change in dynamic mechanical properties upon thermoreversible gelation. The mechanical characteristics of the gels depended strongly upon concentration of total polymer and less so upon copolymer ratio. Increased PEG graft density was shown to slow the deswelling rate and increase the equilibrium water content of the gels. Upon gelation at sol concentrations of 1-20 wt.% the materials underwent no deswelling or syneresis and maintained stable gels with a large elastic regime and high yield strain (i.e. elastic and soft but tough), even within the Pascal range of complex shear moduli. These materials are unique in that they maintained a physiologically useful lower critical solution temperature (approximately 33 degrees C), despite having a high PEG content. Copolymers with a high PEG content and low polymer fraction were conveniently transparent in the gel phase, allowing visualization of cellular activity without disrupting the microenvironment. Mesenchymal stem cells showed good viability and proliferation in three-dimensional culture within the gels, despite the lack of ligand incorporation to promote cellular interaction. Multi-component matrices can be created through simple mixing of copolymer solutions and peptide-conjugated linear polymers and proteins to produce combinatorial microenvironments with the potential for use in cell biology, tissue

  19. Increased diazinon hydrolysis to 2-isopropyl-6-methyl-4-pyrimidinol in liquid medium by a specific Streptomyces mixed culture.

    PubMed

    Briceño, G; Schalchli, H; Rubilar, O; Tortella, G R; Mutis, A; Benimeli, C S; Palma, G; Diez, M C

    2016-08-01

    Actinobacteria identified as Streptomyces spp. were evaluated for their ability to remove diazinon as the only carbon source from a liquid medium. Single cultures of Streptomyces strains were exposed to diazinon at a concentration of 50 mg L(-1). After 96 h incubation, six of the eight cultures grew and five strains showed an increase in their total protein concentrations and changes in their protein profile. Up to 32% of the diazinon was removed by the single Streptomyces cultures. A compatibility assay showed that the different Streptomyces species were not antagonistic. Twenty-six mixed cultures were then prepared. Diazinon removal was increased when mixed cultures were used, and maximum diazinon removal of 62% was observed when the Streptomyces spp. strains AC5, AC9, GA11 and ISP13 were mixed; this was defined as the selected mixed culture (SMC). Diazinon removal was positively influenced by the addition of glucose into the liquid medium. Our study showed a diazinon degradation rate of 0.025 h(-1), half-life of 28 h(-1) and 2-isopropyl-6-methyl-4-pyrimidinol (IMHP) production of 0.143 mg L h(-1). Rapid diazinon hydrolysis to IMHP was associated with a decrease in the pH of the medium as a consequence of microbial glucose metabolism and organic acid exudation. Moreover, the SMC of Streptomyces was able to remove IMHP. This work constitutes a new, if not the only, report on diazinon degradation by mixed cultures of Streptomyces spp. Given the high levels of diazinon removal, the SMC formed by four Streptomyces strains has the potential to be used to treat the diazinon present in environmental matrices.

  20. Effectiveness of isopropyl myristate/cyclomethicone D5 solution of removing cuticular hydrocarbons from human head lice (Pediculus humanus capitis)

    PubMed Central

    2012-01-01

    Background In the treatment of human head lice infestation, healthcare providers are increasingly concerned about lice becoming resistant to existing pesticide treatments. Traditional pesticides, used to control these pests, have a neurological mechanism of action. This publication describes a topical solution with a non-traditional mechanism of action, based on physical disruption of the wax layer that covers the cuticle of the louse exoskeleton. This topical solution has been shown clinically to cure 82% of patients with only a 10-minute treatment time, repeated once after 7 days. All insects, including human head lice, have a wax-covered exoskeleton. This wax, composed of hydrocarbons, provides the insect with protection against water loss and is therefore critical to its survival. When the protective wax is disrupted, water loss becomes uncontrollable and irreversible, leading to dehydration and death. A specific pattern of hydrocarbons has been found in all of the head louse cuticular wax studied. Iso-octane effectively removes these hydrocarbons from human head lice’s cuticular wax. Methods A method of head louse cuticle wax extraction and analysis by gas chromatography was developed. Human head lice (Pediculus humanus capitis) were collected from infested patients and subjected to any of three extraction solvents comprising either the test product or one of two solvents introduced as controls. A gas chromatograph equipped with a flame ionization detector (GC/FID) was used to determine the presence of hydrocarbons in the three head lice extracts. Results In the study reported herein, the test product isopropyl myristate/cyclomethicone D5 (IPM/D5) was shown to perform comparably with iso-octane, effectively extracting the target hydrocarbons from the cuticular wax that coats the human head louse exoskeleton. Conclusions Disruption of the integrity of the insect cuticle by removal of specific hydrocarbons found in the cuticular wax appears to offer a

  1. Solvent extraction of cesium by substituted crown ethers

    SciTech Connect

    Sachleben, R.A.; Deng, Y.; Palmer, D.A.; Moyer, B.A.

    1996-12-31

    The extraction of alkali metal nitrates by 18-crown-6, 21-crown-7, and 24-crown-8 ethers, bearing cyclohexano, benzo-, t-alkylbenzo, and furano- substituents, in 1,2-dichloroethane has been surveyed. Introduction of a furano substituent onto the macrocyclic ring of 18-crown-6 or 21 crown-7 ethers causes a significant reduction in both extraction efficiency and selectivity. Addition of an additional benzo group to dibenzo-21 -crown-7, to give tribenzo-21 -crown-7, decreases both extraction efficiency and selectivity, whereas addition of one or two additional benzo groups to dibenzo-24-crown-8 increases the extraction efficiency and selectivity for the larger ions Rb+ and Cs{sup +} Detailed equilibrium modeling of the extraction by lipophilic 21 -crown-7 ethers indicates that the addition of t-alkyl substituents onto the benzo groups has only a minor effect on the extraction of cesium nitrate by dibenzo-21 -crown-7 ethers.

  2. 46 CFR 151.50-42 - Ethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... shall be designed and tested to meet the rules of the American Bureau of Shipping for a head of water at... liquid. (g) Precautions shall be taken to prevent the contamination of ethyl ether by strong...

  3. Tough poly(arylene ether) thermoplastics as modifiers for bismaleimides

    NASA Technical Reports Server (NTRS)

    Stenzenberger, H. D.; Roemer, W.; Hergenrother, P. M.; Jensen, B. J.

    1989-01-01

    Several aspects of research on thermoplastics as toughness modifiers are discussed, including the contribution of the backbone chemistry and the concentration of the poly(arylene ether) thermoplastic to fracture toughness, influence of the molecular weight of the poly(arylene ether) thermoplastic on neat resin fracture toughness, and the morphology of the thermoplastic modified networks. The results show that fracture toughness of brittle bismaleimide resins can be improved significantly with poly(arylene ether) thermoplastic levels of 20 percent by weight, and that high molecular weight poly(arylene ether) based on bisphenol A provides the highest degree of toughening. Preliminary composite evaluation shows that improvements in neat resin toughness translate into carbon fabric composite.

  4. POLYBROMINATED DIPHENYL ETHERS IN HOUSE DUST AND CLOTHES DRYER LINT

    EPA Science Inventory

    Polybrominated diphenyl ether (PBDE) flame retardants are now considered ubiquitous and persistent pollutants. Few studies have examined the concentrations of these chemicals in the home and here we report measurements of PBDEs in house dust samples collected from the Washington...

  5. 36. BUILDINGS NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. BUILDINGS NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, AND NO. 523, REFRIGERATION PLANT BUILDING, LOOKING EAST. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  6. 44. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, LOOKING UP DISTILLATION TOWER FROM 2ND LEVEL. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  7. POLYBROMINATED DIPHENYL ETHERS (PBDES) CONTAMINATION OF UNITED STATES FOOD

    EPA Science Inventory

    Elevated levels of polybrominated diphenyl ethers (PBDEs), a type of brominated flame retardant, were recently detected in United States (U.S.) nursing mothers' milk. These halogenated compounds chemically and toxicologically resemble others such as polychlorinated biphenyls (PC...

  8. A short synthesis of ±-cherylline dimethyl ether.

    PubMed

    Kale, Bhima Y; Shinde, Ananta D; Sonar, Swapnil S; Shingate, Bapurao B; Kumar, Sanjeev; Ghosh, Samir; Venugopal, Soodamani; Shingare, Murlidhar S

    2009-01-01

    A synthesis of ±-cherylline dimethyl ether is reported. The key steps involved are Michael-type addition, radical azidonation of an aldehyde, Curtius rearrangement, and reduction of an isocyanate intermediate followed by Pictet-Spengler cyclization.

  9. Partial cone calix[4]arene-crown-6-ethers

    SciTech Connect

    Das, G.; Sachleben, R.A.; Descazeaud, T.; Bryan, J.C.; Moyer, B.A.

    1997-12-31

    Partial cone calix[4] arene crown ethers represents a new category of lariat ethers. In general, calix arene crown ethers have been previously shown to be efficient extractants for metal cations. Appropriately substituted cone and 1, 3-alt conformers of calix crowns exhibit selectivities for Na{sup +} and Cs{sup +}, respectively. The partial cone conformers have not been as throughly studied. We have developed an efficient method of synthesis of partial cone calix[4]arene-crown ethers and have synthesized a variety of partial cone calix[4]arene crowns. Solution and solid-state structures of representative examples have been determined by {sup 1}H NMR spectroscopy and X-ray crystallography. Relative affinities of these partial cone calix[4]arene crowns for alkali metal ions have been investigated by solvent extraction techniques.

  10. Effect of diethyl ether on the biliary excretion of acetaminophen.

    PubMed

    Watkins, J B; Siegers, C P; Klaassen, C D

    1984-10-01

    The biliary and renal excretion of acetaminophen and its metabolites over 8 hr was determined in rats exposed to diethyl ether by inhalation for 1 hr. Additional rats were anesthetized with urethane (1 g/kg ip) while control animals were conscious throughout the experiment (surgery was performed under hexobarbital narcosis: 150 mg/kg ip; 30-min duration). The concentration of UDP-glucuronic acid was decreased 80% in livers from ether-anesthetized rats but was not reduced in urethane-treated animals when compared to that in control rats. The concentration of reduced glutathione was not affected by either urethane or diethyl ether. Basal bile flow was not altered by the anesthetic agents. Bile flow rate after acetaminophen injection (100 mg/kg iv) was increased slightly over basal levels for 2 hr in hexobarbital-treated control rats, was unaltered in urethane-anesthetized animals, and was decreased throughout the 8-hr experiment in rats exposed to diethyl ether for 1 hr. In control and urethane-anesthetized animals, approximately 30-35% of the total acetaminophen dose (100 mg/kg iv) was excreted into bile in 8 hr, while only 16% was excreted in rats anesthetized with diethyl ether. Urinary elimination (60-70% of the dose) was not altered by exposure to ether. Separation of metabolites by reverse-phase high-pressure liquid chromatography showed that ether decreased the biliary elimination of unchanged acetaminophen and its glucuronide, sulfate, and glutathione conjugates by 47, 40, 49, and 73%, respectively, as compared to control rats. Excretion of unchanged acetaminophen and the glutathione conjugate into bile was depressed in urethane-anesthetized animals by 45 and 66%, respectively, whereas elimination of the glucuronide and sulfate conjugates was increased by 27 and 50%, respectively. These results indicate that biliary excretion is influenced by the anesthetic agent and that diethyl ether depresses conjugation with sulfate and glutathione as well as glucuronic

  11. Dimethyl ether (DME) as an alternative fuel

    NASA Astrophysics Data System (ADS)

    Semelsberger, Troy A.; Borup, Rodney L.; Greene, Howard L.

    With ever growing concerns on environmental pollution, energy security, and future oil supplies, the global community is seeking non-petroleum based alternative fuels, along with more advanced energy technologies (e.g., fuel cells) to increase the efficiency of energy use. The most promising alternative fuel will be the fuel that has the greatest impact on society. The major impact areas include well-to-wheel greenhouse gas emissions, non-petroleum feed stocks, well-to-wheel efficiencies, fuel versatility, infrastructure, availability, economics, and safety. Compared to some of the other leading alternative fuel candidates (i.e., methane, methanol, ethanol, and Fischer-Tropsch fuels), dimethyl ether appears to have the largest potential impact on society, and should be considered as the fuel of choice for eliminating the dependency on petroleum. DME can be used as a clean high-efficiency compression ignition fuel with reduced NO x, SO x, and particulate matter, it can be efficiently reformed to hydrogen at low temperatures, and does not have large issues with toxicity, production, infrastructure, and transportation as do various other fuels. The literature relevant to DME use is reviewed and summarized to demonstrate the viability of DME as an alternative fuel.

  12. Polybrominated diphenyl ether (PBDE) flame retardants.

    PubMed

    Rahman, F; Langford, K H; Scrimshaw, M D; Lester, J N

    2001-07-25

    Polybrominated diphenyl ether, PBDE, flame retardants are now a world-wide pollution problem reaching even remote areas. They have been found to bioaccumulate and there are concerns over the health effects of exposure to PBDEs, they also have potential endocrine disrupting properties. They are lipophilic compounds so are easily removed from the aqueous environment and are predicted to sorb onto sediments and particulate matter or to fatty tissue, aiding their distribution throughout the environment. PBDEs are structurally similar to PCBs and DDT and, therefore, their chemical properties, persistence and distribution in the environment follow similar patterns. Concentrations of PBDEs found in environmental samples are now higher than those of PCBs. Evidence to date demonstrates that PBDEs are a growing problem in the environment and concern over their fate and effects is warranted. The manufacture of reactive and additive flame retardants is briefly discussed and their fate and behaviour in the environment is assessed. PBDE toxicology is reviewed and methods of analysis are evaluated.

  13. Measurement of Polybrominated Diphenyl Ethers and Metabolites in Mouse Plasma after Exposure to a Commercial Pentabromodiphenyl Ether Mixture

    PubMed Central

    Qiu, Xinghua; Mercado-Feliciano, Minerva; Bigsby, Robert M.; Hites, Ronald A.

    2007-01-01

    Background Previous studies have shown that polybrominated diphenyl ethers (PBDEs) behave as weak estrogens in animal and cell culture bioassays. In vivo metabolites of PBDEs are suspected to cause these effects. Objectives To identify candidate metabolites, mouse plasma samples were collected after continuous oral and subcutaneous exposure to DE-71, a widely used commercial pentabromodiphenyl ether product, for 34 days. Methods Samples were extracted, separated into neutral and phenolic fractions, and analyzed by gas chromatographic mass spectrometry. Results In the plasma samples of orally treated animals, 2,2′,4,4′,5,5′-hexabromodiphenyl ether (BDE-153) represented 52% of total measurable PBDEs, whereas it represented only 4.3% in the DE-71 mixture. This suggested that BDE-153 was more persistent than other congeners in mice. Several metabolites were detected and quantitated: 2,4-dibromophenol, 2,4,5-tribromophenol, and six hydroxylated PBDEs. The presence of the two phenols suggested cleavage of the ether bond of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and 2,2′,4,4′,5-pentabromodiphenyl ether (BDE-99), respectively. The hydroxylated (HO)-PBDEs might come from hydroxylation or debromination/hydroxylation. Among the quantitated hydroxylated metabolites, the most abundant was 4-HO-2,2′,3,4′-tetra-BDE, which suggested that there was a bromine shift during the hydroxylation process. para-HO-PBDEs have been proposed to behave as endocrine disruptors. Conclusions There seem to be three metabolic pathways: cleavage of the diphenyl ether bond, hydroxylation, and debromination/hydroxylation. The cleavage of the diphenyl ether bond formed bromophenols, and the other two pathways formed hydroxylated PBDEs, of which para-HO-PBDEs are most likely formed from BDE-47. These metabolites may be the most thyroxine-like and/or estrogen-like congeners among the HO-PBDEs. PMID:17637922

  14. Hexavalent chromium reduction by tartaric acid and isopropyl alcohol in Mid-Atlantic soils and the role of Mn(III,IV)(hydr)oxides.

    PubMed

    Brose, Dominic A; James, Bruce R

    2013-11-19

    Chromium is a naturally occurring transition metal and a soil contaminant in the Cr(VI) oxidation state, but reduction of Cr(VI) to Cr(III) mitigates its toxicity. Tartaric acid reduces Cr(VI) via a termolecular complex with isopropyl alcohol and Cr(VI), but its efficacy in soils has not been demonstrated. Five Mid-Atlantic soils from Maryland, U.S. were examined for their potential to enhance the reduction of Cr(VI). A control treatment (no soil +12 mM tartaric acid + 0.29 M isopropyl alcohol) reduced 0.37 mM Cr(VI) (19%) in 99 h. Reduction was enhanced to 1.97 mM (99%) with addition of a Russett Ap soil horizon (fine-loamy, mixed, semiactive, mesic Typic Hapludult). With a half-life of 18.7 h, the rate of reduction of Cr(VI) with the Russett soil sample was 20 times faster than with no soil (371 h). Soil Mn was solubilized in this reaction and plays a role in the enhanced reduction of Cr(VI). Mn(III/IV)(hydr)oxide-coated quartz sand reduced 1.24 mM (62%) Cr(VI), with all of the Mn(III,IV)(hydr)oxides solubilized. The addition of isopropyl alcohol and tartaric acid to soils enhances the reduction of Cr(VI), and this reduction is further enhanced by the catalytic behavior of Mn(II) from easily reducible Mn(III,IV)(hydr)oxides in soil.

  15. (2R,3S,4R)-3,4-Isopropyl­idenedi­oxy-2-(phenyl­sulfonyl­meth­yl)pyrrolidin-1-ol

    PubMed Central

    Flores, Mari Fe; Garcia, Pilar; M. Garrido, Narciso; Sanz, Francisca; Diez, David

    2012-01-01

    The title compound, C14H19NO5S, was prepared by nucleophilic addition of the lithium derivative of methyl­phenyl­sulfone to (3S,4R)-3,4-isopropyl­idene­dioxy­pyrroline 1-oxide. There are four mol­ecules in the asymmetric unit. The crystal structure determination confirms the configuration of the chiral centres as 2R,3S,4R. In the crystal, pairs of O—H⋯N hydrogen bonds link the mol­ecules into dimers. PMID:22904989

  16. 3,5-Dimethyl-3'-isopropyl-l-thyronine therapy in diabetic pregnancy: stimulation of rabbit fetal lung phospholipids.

    PubMed Central

    Neufeld, N; Melmed, S

    1981-01-01

    Diabetes mellitus in pregnancy is associated with neonatal respiratory distress syndrome due to impaired synthesis of fetal lung surfactant. Pharmacologic agents that promote fetal lung maturity are diabetogenic and have limited use in the management of diabetic pregnancy for prevention of respiratory distress syndrome. Maternal administration of a thyroid analog 3,5-dimethyl-3'-isopropyl-L-thyronine (DIMIT) results in significant enhancement of fetal lung phospholipid synthesis and accelerated lung maturity. We therefore studied the effects of DIMIT (0.5 mg/kg per d, s.c.) administration to pregnant alloxan-diabetic rabbits on days 25 and 26 of gestation. DIMIT treatment of diabetic maternal rabbits (DD) was associated with reduction of maternal blood glucose (115 +/- 13 vs. 275 +/- 72 mg/dl, P less than 0.05) and fetal glucose (64 +/- 6 vs. 274 +/- 47 mg/dl, P less than 0.001) compared with saline-injected diabetic (D) mothers. Reduction of fetal insulin levels was also associated with maternal DIMIT therapy in diabetic rabbits (56 +/- 5 (D) vs. 24 +/- 4 microunits/ml, P less than 0.001). Maternal diabetes resulted in significant reduction of fetal lung weight (370 +/- 20 vs. 520 +/- 30 mg, P less than 0.005) and lung protein content (6.5 +/- 0.7 vs. 8.7 +/- 0.7 mg/gm, P less than 0.005), which were restored to normal in offspring of DIMIT-treated diabetic rabbits. Maternal DIMIT administration caused significant reduction in fetal lung glycogen content in control (62 +/- 5.8 vs. 25 +/- 5.9 micrograms/mg protein, P less than 0.001) and diabetic (56 +/- 7 vs. 34 +/- 5 micrograms/mg protein, P less than 0.02) offspring. Whereas maternal diabetes was associated with reduction of all major phospholipid species in fetal lung-comprising surfactant, these were restored with DIMIT therapy. The results demonstrate that short-term maternal administration of DIMIT in pregnant diabetic rabbits not only promotes fetal lung phospholipid synthesis, but also appears to

  17. Transplacental stimulation of lung development in the fetal rabbit by 3,5-dimethyl-3'-isopropyl-L-thyronine.

    PubMed Central

    Ballard, P L; Benson, B J; Brehier, A; Carter, J P; Kriz, B M; Jorgensen, E C

    1980-01-01

    The effect of thyroid hormone on maturation of fetal rabbit lung was studied with maternal treatment using 3,5-dimethyl-3'-isopropyl-L-thyronine (DIMIT), a synthetic analogue of triiodothyronine. To investigate the in vivo kinetics and distribution of DIMIT, we prepared [3H]DIMIT and injected both pregnant rats (18-21 d gestation) and rabbits (25 d gestation). In the rat, maximal concentrations of radioactivity in maternal plasma, fetal plasma, and amniotic fluid occurred within 10 min, 1-2 h, and 4-6 h, respectively, after intramuscular injection. After 7 h the concentration of radioactivity in fetal plasma was 163 and 71% of the maternal level in rats and rabbits, respectively, indicating that DIMIT readily crosses the placenta. We treated pregnant rabbits for 1-2 d with DIMIT in doses of 0.5-3 mg/kg per d and examined the fetuses at 26 and 27 d gestation. Treatment did not affect fetal growth or viability. In fetal liver, DIMIT increased the activity of NADPH cytochromeac reductase by 64% and decreased the glycogen content by 73% compared to controls. The rate of choline incorporation by lung minces increased in dose-dependent manner to a maximum of +104% at 3 mg/kg DIMIT; this does stimulated by 38% the activity of lung phosphatidic acid phosphatase (PAPase), a corticosteroid-responsive enzyme, but there was no increase in tissue PAPase activity at most lower doses of DIMIT that enhanced choline incorporation. Treated lungs had 38% less glycogen tha controls, but there was no effect on tissue levels of DNA, protein, or phospholipid. DIMIT treatment increased the amount of total phospholipid (+163%). saturated phosphatidylcholine (+330%), and PAPase activity (+134%) in lung lavage fluid. The DIMIT effects on both choline incorporation by lung minces and phospholipid content of lavage fluid were substantially greater than what had occurred with an optimal dose of betamethasone. DIMIT also increased corticosteroid binding capacity in fetal plasma and produced a

  18. A novel sulfonated poly(ether ether ketone) and cross-linked membranes for fuel cells

    NASA Astrophysics Data System (ADS)

    Li, Hongtao; Zhang, Gang; Wu, Jing; Zhao, Chengji; Zhang, Yang; Shao, Ke; Han, Miaomiao; Lin, Haidan; Zhu, Jing; Na, Hui

    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 1H 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 × 10 4 S s cm -3, which indicates that it is a suitable candidate for applications in direct methanol fuel cells.

  19. Investigation of crystalline morphology in poly (ether ether ketone) using dielectric relaxation spectroscopy

    SciTech Connect

    Kalika, D.S.; Krishnaswamy, R.K.

    1993-12-31

    The relaxation behavior of poly (ether ether ketone) [PEEK] has been investigated using dielectric relaxation spectroscopy; the glass-rubber ({alpha}) relaxation and a sub-glass ({beta}) relaxation were examined for the amorphous material and both cold-crystallized and melt-crystallized specimens. Analysis of the data using the Cole-Cole modification of the Debye equation allowed determination of the dielectric relaxation strength and relaxation broadening parameter for both transitions as a function of material crystallization history. The crystallized specimens displayed a positive offset in isochronal loss temperature for both the {alpha} and {beta} relaxations, with the {alpha} relaxation broadened significantly. The measured dipolar response was interpreted using a three-phase morphological model encompassing a crystalline phase, a mobile amorphous phase, and a rigid amorphous phase. Determination of phase fractions based on dipolar mobilization across the glass-rubber relaxation revealed a finite rigid amorphous phase fraction for both the cold-crystallized specimens which was relatively insensitive to thermal history and degree of crystallinity (W{sub RAP}40.20).

  20. Copoly(arlene ether)s containing pendant sulfonic acid groups as proton exchange membrane

    SciTech Connect

    Kim, Yu Seung; Kim, Dae Sik; Robertson, Gilles; Guiver, Michael

    2008-01-01

    A copoly(arylene ether) (PAE) with high fluorine content and a copoly(arylene ether nitrile) (PAEN) with high nitrile content, each containing pendant phenyl sulfonic acids were synthesized. The P AE and PAEN were prepared from decafluorobiphenyl (DFBP) and difluorobenzonitrile (DFBN) respectively, by polycondensation with 2-phenylhydroquinone (PHQ) by conventional aromatic nucleophilic substitution reactions. The sulfonic acid groups were introduced by mild post-sulfonation exclusively on the para-position of the pendant phenyl ring in PHQ. The membrane properties of the resulting sulfonated copolymers sP AE and sP AEN were compared for fuel cell applications. The copolymers sPAE and sPAEN, each having a degree of sulfonation (DS) of 1.0 had high ion exchange capacities (IEC{sub v}(wet) (volume-based, wet state)) of 1.77 and 2.55 meq./cm{sup 3}, high proton conductivities of 135.4 and 140.1 mS/cm at 80 C, and acceptable volume-based water uptake of 44.5-51.9 vol% at 80 C, respectively, compared to Nafion. The data points of these copolymer membranes are located in the area of outstanding properties in the trade-off plot of alternative hydrocarbon polyelectrolyte membranes (PEM) for the relationship between proton conductivity versus water uptake (weight based or volume based). Furthermore, the relative selectivity derived from proton conductivity and methanol permeability is higher than that of Nafion.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Molecular sieve/sulfonated poly(ether ketone ether sulfone) composite membrane as proton exchange membrane

    NASA Astrophysics Data System (ADS)

    Changkhamchom, Sairung; Sirivat, Anuvat

    2012-02-01

    A proton exchange membrane (PEM) is an electrolyte membrane used in both polymer electrolyte membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFCs). Currently, PEMs typically used for PEMFCs are mainly the commercially available Nafion^ membranes, which is high cost and loss of proton conductivity at elevated temperature. In this work, the Sulfonated poly(ether ketone ether sulfone), (S-PEKES), was synthesized by the nucleophilic aromatic substitution polycondensation between bisphenol S and 4,4'-dichlorobenzophenone, and followed by the sulfonation reaction with concentrated sulfuric acid. The molecular sieve was added in the S-PEKES matrix at various ratios to form composite membranes to be the candidate for PEM. Properties of both pure sulfonated polymer and composite membranes were compared with the commercial Nafion^ 117 membrane from Dupont. S-PEKES membranes cast from these materials were evaluated as a polymer electrolyte membrane for direct methanol fuel cells. The main properties investigated were the proton conductivity, methanol permeability, thermal, chemical, oxidative, and mechanical stabilities by using a LCR meter, Gas Chromatography, Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy, Fenton's reagent, and Universal Testing Machine. The addition of the molecular sieve helped to increase both the proton conductivity and the methanol stability. These composite membranes are shown as to be potential candidates for use as a Proton Exchange Membrane (PEM).

  3. Why do crown ethers activate enzymes in organic solvents?

    PubMed

    van Unen, Dirk-Jan; Engbersen, Johan F J; Reinhoudt, David N

    2002-02-01

    One of the major drawbacks of enzymes in nonaqueous solvents is that their activity is often dramatically low compared to that in water. This limitation can be largely overcome by crown ether treatment of enzymes. In this paper, we describe a number of carefully designed new experiments that have improved the insights into the mechanisms that are operative in the crown ether activation of enzymes in organic solvents. The enhancement of enzyme activity upon addition of 18-crown-6 to the organic solvent can be reconciled with a mechanism in which macrocyclic interactions of 18-crown-6 with the enzyme play an important role. Macrocyclic interactions (e.g., complexation with lysine ammonium groups of the enzyme) can lead to a reduced formation of inter- and intramolecular salt bridges and, consequently, to lowering of the kinetic conformational barriers, enabling the enzyme to refold into thermodynamically stable, catalytically (more) active conformations. This assumption is supported by the observation that the crown-ether-enhanced enzyme activity is retained after removal of the crown by washing with a dry organic solvent. A much stronger crown ether activation is observed when 18-crown-6 is added prior to lyophilization, and this can be explained by a combination of two effects: the before-mentioned macrocyclic complexation effect, and a less specific, nonmacrocyclic, lyoprotecting effect. The magnitude of the total crown ether effect depends on the polarity and thermodynamic water activity of the solvent, the activation being highest in dry and apolar media, where kinetic conformational barriers are highest. By determination of the specific activity of crown-ether-lyophilized enzyme as a function of the enzyme concentration, the macrocyclic crown ether (linearly dependent on the enzyme concentration) and the nonmacrocyclic lyoprotection effect (not dependent on the enzyme concentration) could be separated. These measurements reveal that the contribution of the

  4. Mutagenicity testing of diethylene glycol monobutyl ether.

    PubMed Central

    Thompson, E D; Coppinger, W J; Valencia, R; Iavicoli, J

    1984-01-01

    The mutagenic potential of diethylene glycol monobutyl ether (diEGBE) was examined with a Tier I battery of in vitro assays followed by a Tier II in vivo Drosophila sex-linked recessive lethal assay. The in vitro battery consisted of: the Salmonella mutagenicity test, the L5178Y mouse lymphoma test, a cytogenetics assay using Chinese hamster ovary cells and the unscheduled DNA synthesis (UDS) assay in rat hepatocytes. Results of the Salmonella mutagenicity test, the cytogenetics test, and the rat hepatocyte assay were negative at concentrations up to 20 microL/plate, 7.92 microL/mL, and 4.4 microL/mL, respectively. Toxicity was clearly demonstrated at all high doses. A weak, but dose-related increase in the mutation frequency (4-fold increase over the solvent control at 5.6 microL/mL with 12% survival) was obtained in the L5178Y lymphoma test in the absence of metabolic activation. Results of the mouse lymphoma assay were negative in the presence of the S-9 activation system. The significance of the mouse lymphoma assay were negative in the presence of the S-9 activation system. The significance of the mouse lymphoma assay results were assessed by performing the Tier II sex-linked recessive lethal assay in Drosophila in which the target tissue is maturing germinal cells. Both feeding (11,000 ppm for 3 days) and injection (0.3 microL of approximately 14,000 ppm solution) routes of administration were employed in the Drosophila assay. Approximately 11,000 individual crosses with an equal number of negative controls were performed for each route of administration. diEGBE produced no increase in recessive lethals under these conditions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6389113

  5. Synthesis of 6-Methyl-9-propyldibenzothiophene-4-ol amended to 9-isopropyl-6-methyldibenzothiophene-4-ol. Final technical report, July 25, 1991--January 25, 1993

    SciTech Connect

    Eisenbraun, E.J.

    1992-02-17

    This is a draft final technical report on Task 1 of a contract to synthesize 6-Methyl-9-propyldibenzothiophene-4-ol, as amended to 9- isopropyl-6-methyldibenzothiophene-4-ol. This report is a compilation of data presented in earlier reports. The first annual report dealt with an attempted synthesis of 4-methoxy-6-methyl-9- propyldibenzothiophene (the original target compound), the successful synthesis and delivery of 200 grams of the sulfide 1,4-diethyl-2- [(2{prime}-methoxyphenyl)-thio]benzene, and initial work on a new synthesis route for the preparation of the new target compound 9- isopropyl-6-methyldibenzothiophene-4-ol. The change to the new target compound and the new synthesis route became necessary when it was learned that the sulfide mixture could not be cyclized to the substituted dibenzothiophene mixture. The second annual report described the successful preparation of 45 g of the new target compound using the new synthesis route. Subsequently funds were provided to synthesize an additional 45 g of the new target using the same reaction scheme. This task was recently completed.

  6. Integrated process for the production of diisopropyl ether and gasoline

    SciTech Connect

    Owen, H.; Harandi, M.N.

    1992-04-07

    This patent describes an integrated process for the production of diisopropyl ether and C{sub 5+} gasoline boiling range hydrocarbons. It comprises contacting C{sub 3} hydrocarbon feedstock and high pressure separator aqueous effluent recycle stream with acidic hydration and etherification catalyst in an etherification zone under etherification conditions to produce an effluent stream containing diisopropyl ether, isopropanol, unreacted water, unreacted C{sub 3} hydrocarbons and higher olefinic hydrocarbons; separating and extracting the effluent stream in a high pressure separation zone in contact with fresh water feed-stream to produce the aqueous effluent recycle stream containing a portion of the isopropanol and unreacted water and a separation zone effluent stream containing diisopropyl ether, unextracted isopropanol, unreacted C{sub 3} hydrocarbons and higher olefinic hydrocarbons; heating and flashing the separator effluent stream at a temperature sufficient to further separate the separator effluent to produce a flash evaporator overhead vapor stream for compression and recycle to the etherification zone, the recycle stream containing a major portion of the unreacted C{sub 3} hydrocarbons, and an evaporator bottom steam containing diisopropyl ether, unextracted isopropanol, a minor portion of the unreacted C{sub 3} hydrocarbons and higher olefinic hydrocarbons; separating the evaporator bottom stream to produce diisopropyl ether, a first stream containing C{sub 3} hydrocarbons and a second stream containing isopropanol and higher olefinic hydrocarbons.

  7. Optimisation of a 5-[3-phenyl-(2-cyclic-ether)-methyl-ether]-4-aminopyrrolopyrimidine series of IGF-1R inhibitors.

    PubMed

    Fairhurst, Robin A; Marsilje, Thomas H; Stutz, Stefan; Boos, Andreas; Niklaus, Michel; Chen, Bei; Jiang, Songchun; Lu, Wenshuo; Furet, Pascal; McCarthy, Clive; Stauffer, Frédéric; Guagnano, Vito; Vaupel, Andrea; Michellys, Pierre-Yves; Schnell, Christian; Jeay, Sébastien

    2016-04-15

    Taking the pyrrolopyrimidine derived IGF-1R inhibitor NVP-AEW541 as the starting point, the benzyl ether back-pocket binding moiety was replaced with a series of 2-cyclic ether methyl ethers leading to the identification of novel achiral [2.2.1]-bicyclic ether methyl ether containing analogues with improved IGF-1R activities and kinase selectivities. Further exploration of the series, including a fluorine scan of the 5-phenyl substituent, and optimisation of the sugar-pocket binding moiety identified compound 33 containing (S)-2-tetrahydrofuran methyl ether 6-fluorophenyl ether back-pocket, and cis-N-Ac-Pip sugar-pocket binding groups. Compound 33 showed improved selectivity and pharmacokinetics compared to NVP-AEW541, and produced comparable in vivo efficacy to linsitinib in inhibiting the growth of an IGF-1R dependent tumour xenograft model in the mouse.

  8. Methyl tertiary hexyl ether and methyl tertiary octyl ether as gasoline oxygenates: assessing risks from atmospheric dispersion and deposition.

    PubMed

    Snelling, Jeff; Barnett, Mark O; Zhao, Dongye; Arey, J Samuel

    2006-10-01

    Methyl tertiary hexyl ether (MtHxE) and methyl tertiary octyl ether (MtOcE) are currently being developed as replacement oxygenates for methyl tertiary butyl ether (MtBE) in gasoline. As was the case with MtBE, the introduction of these ethers into fuel supplies guarantees their introduction into the environment as well. In this study, a screening-level risk assessment was performed by comparing predicted environmental concentrations (PEC) of these ethers to concentrations that might cause adverse effects to humans or ecosystems. A simple box model that has successfully estimated urban air concentrations of MtBE was adapted to predict atmospheric concentrations of MtHxE and MtOcE. Expected atmospheric concentrations of these ethers were also estimated using the European Union System for the Evaluation of Substances (EUSES) multimedia fate model, which simultaneously calculates PECs in the various environmental compartments of air, water, soil, and sediment. Because little or no data are available on the physicochemical, environmental, and toxicological properties of MtHxE and MtOcE, estimation methods were used in conjunction with EUSES to predict both the PECs and the concentrations at which these ethers might pose a threat. The results suggest that these ethers would contaminate the air of a moderately sized U.S. city (Boston, MA) at levels similar to those found previously for MtBE. The risk assessment module in EUSES predicted risk characterization ratios of 10(-3) and 10(-2) for MtHxE and MtOcE, respectively, in Boston, and 10(-2) and 10(-1) in very large urban centers, suggesting that these ethers pose only a minimal threat to ecosystems at the anticipated environmental concentrations. The assessment also indicates that these compounds are possible human carcinogens and that they may be present in urban air at concentrations that pose an unacceptable cancer risk. Therefore, testing of the toxicological properties of these compounds is recommended before they

  9. Copoly(arylene ether)s containing pendant sulfonic acid groups as proton exchange membranes

    SciTech Connect

    Dae Sik, Kim; Yu Seung, Kim; Gilles, Robertson; Guiver, Michael D

    2009-01-01

    A copoly(arylene ether) (PAE) with high fluorine content and a copoly(arylene ether nitrile) (PAEN) with high nitrile content, each containing pendant phenyl sulfonic acids were synthesized. The PAE and P AEN were prepared from decafluorobiphenyl (DFBP) and difluorobenzonitrile (DFBN) respectively, by polycondensation with 2phenylhydroquinone (PHQ) by conventional aromatic nucleophilic substitution reactions. sulfonic acid groups were introduced by mild post-sulfonation exclusively on the para-position of the pendant phenyl ring in PHQ. The membrane properties of the resulting sulfonated copolymers sPAE and sPAEN were compared for fuel cell applications. The copolymers sPAE and sPAEN, each having a degree of sulfonation (OS) of 1.0 had high ion exchange capacities (IEC{sub v})(wet) (volume-based, wet state) of 1.77 and 2.55 meq./cm3, high proton conductivities of 135.4 and 140.1 mS/cm at 80 C, and acceptable volume-based water uptake of 44.5 -51.9 vol% at 80 C, respectively, compared to Nafion. The data points of these copolymer membranes are located in the upper left-hand corner in the trade-off plot of alternative hydrocarbon polyelectrolyte membranes (PEM) for the relationship between proton conductivity versus water uptake (weight based or volume based), i.e., high proton conductivity and low water uptake. Furthermore, the relative selectivity derived from proton conductivity and methanol permeability is higher than that of Nafion.

  10. Safety assessment of alkyl PEG ethers as used in cosmetics.

    PubMed

    Fiume, Monice M; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2012-01-01

    The CIR Expert Panel assessed the safety of Alkyl PEG Ethers as used in cosmetics. These ingredients primarily function in cosmetics as surfactants, and some have additional functions as skin-conditioning agents, fragrance ingredients, and emulsion stabilizers. The Panel reviewed available relevant animal and clinical data, as well as information from previous CIR reports; when data were not available for individual ingredients, the Panel extrapolated from the existing data to support safety. The Panel concluded that the Alkyl PEG ethers are safe as used when formulated to be nonirritating, and the same applies to future alkyl PEG ether cosmetic ingredients that vary from those ingredients recited herein only by the number of ethylene glycol repeat units.

  11. Oxidative acetoxylation of the silyl ethers of ketone enols

    SciTech Connect

    Brunovlenskaya, I.I.; Kusainova, K.M.; Kashin, A.K.

    1988-07-20

    The authors studied the reaction of (dicarboxyiodo)benzenes with the trimethylsilyl ethers of ketone enols having various structures. They also undertook a comparative investigation of the oxidation of these compounds with lead tetraacetate. The reaction of (diacetoxyiodo)benzene with the trimethylsilyl ethers of ketone enols takes place with retention of the (CH/sub 3/)/sub 3/Si group in two directions, i.e., substitution of the vinylic hydrogen or diacetoxylation of the double bond. The reaction can be used for the regioselective synthesis of /alpha/-acetoxy ketones, since the trimethylsilyl group is readily eliminated from the obtained products by the action of fluoride ion or boron trifluoride etherate with the formation of the corresponding substituted ketones.

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

    PubMed

    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

  13. Conversion of light hydrocarbons to ether rich gasoline

    SciTech Connect

    Bell, W.K.; Haag, W.O.; Harandi, M.N.; Owen, H.

    1991-05-07

    This patent describes an integrated process for the production of ether-rich rich liquid fuels. It comprises: contacting a fresh mixture of lower alkanol and a light hydrocarbon feedstock containing linear olefins and C{sub 4} + tertiary olefins; separating the etherification effluent stream consisting of ether rich C{sub 5} + and C{sub 5{minus}}; contacting second stream with an acidic catalyst in a second etherification zone under conditions effective to etherify the linear olefinic hydrocarbons; recovering a first stream comprising C{sub 5} + gasoline containing lower alkyl ethers of the C{sub 5{minus}}; and passing the second stream to an olefins to higher molecular weight hydrocarbons conversion zone.

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

    USGS Publications Warehouse

    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.

  15. Supramolecular polymers constructed by crown ether-based molecular recognition.

    PubMed

    Zheng, Bo; Wang, Feng; Dong, Shengyi; Huang, Feihe

    2012-03-01

    Supramolecular polymers, polymeric systems beyond the molecule, have attracted more and more attention from scientists due to their applications in various fields, including stimuli-responsive materials, healable materials, and drug delivery. Due to their good selectivity and convenient enviro-responsiveness, crown ether-based molecular recognition motifs have been actively employed to fabricate supramolecular polymers with interesting properties and novel applications in recent years. In this tutorial review, we classify supramolecular polymers based on their differences in topology and cover recent advances in the marriage between crown ether-based molecular recognition and polymer science.

  16. Studies of poly(ether)urethane pacemaker lead insulation oxidation.

    PubMed

    Thoma, R J; Phillips, R E

    1987-04-01

    Published reports suggest that silver ions may catalyze the oxidation of poly(ether)urethane soft-segments resulting in the failure of urethane insulations of specific models of pacemaker leads. Attempted oxidation of soft-segment models, poly(tetra-methylene ether)glycols, by silver nitrate has shown that metal-ion catalyzed oxidative-reduction (MICOR) does not adequately explain observed failures unless antioxidants are removed in process. Such cracking can, however, be explained in terms of a metal ion enhanced environmental stress cracking. PMID:3584162

  17. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  18. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  19. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  20. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  1. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  2. Aliphatic polycarbonates based on carbon dioxide, furfuryl glycidyl ether, and glycidyl methyl ether: reversible functionalization and cross-linking.

    PubMed

    Hilf, Jeannette; Scharfenberg, Markus; Poon, Jeffrey; Moers, Christian; Frey, Holger

    2015-01-01

    Well-defined poly((furfuryl glycidyl ether)-co-(glycidyl methyl ether) carbonate) (P((FGE-co-GME)C)) copolymers with varying furfuryl glycidyl ether (FGE) content in the range of 26% to 100% are prepared directly from CO2 and the respective epoxides in a solvent-free synthesis. All materials are characterized by size-exclusion chromatography (SEC), (1)H NMR spectroscopy, and differential scanning calorimetry (DSC). The furfuryl-functional samples exhibit monomodal molecular weight distributions with Mw/Mn in the range of 1.16 to 1.43 and molecular weights (Mn) between 2300 and 4300 g mol(-1). Thermal properties reflect the amorphous structure of the polymers. Both post-functionalization and cross-linking are performed via Diels-Alder chemistry using maleimide derivatives, leading to reversible network formation. This transformation is shown to be thermally reversible at 110 °C.

  3. Aliphatic polycarbonates based on carbon dioxide, furfuryl glycidyl ether, and glycidyl methyl ether: reversible functionalization and cross-linking.

    PubMed

    Hilf, Jeannette; Scharfenberg, Markus; Poon, Jeffrey; Moers, Christian; Frey, Holger

    2015-01-01

    Well-defined poly((furfuryl glycidyl ether)-co-(glycidyl methyl ether) carbonate) (P((FGE-co-GME)C)) copolymers with varying furfuryl glycidyl ether (FGE) content in the range of 26% to 100% are prepared directly from CO2 and the respective epoxides in a solvent-free synthesis. All materials are characterized by size-exclusion chromatography (SEC), (1)H NMR spectroscopy, and differential scanning calorimetry (DSC). The furfuryl-functional samples exhibit monomodal molecular weight distributions with Mw/Mn in the range of 1.16 to 1.43 and molecular weights (Mn) between 2300 and 4300 g mol(-1). Thermal properties reflect the amorphous structure of the polymers. Both post-functionalization and cross-linking are performed via Diels-Alder chemistry using maleimide derivatives, leading to reversible network formation. This transformation is shown to be thermally reversible at 110 °C. PMID:25407342

  4. Degradation of various alkyl ethers by alkyl ether-degrading Actinobacteria isolated from activated sludge of a mixed wastewater treatment.

    PubMed

    Kim, Yong-Hak; Cha, Chang-Jun; Engesser, Karl-Heinrich; Kim, Sang-Jong

    2008-11-01

    Various substrate specificity groups of alkyl ether (AE)-degrading Actinobacteria coexisted in activated sewage sludge of a mixed wastewater treatment. There were substrate niche overlaps including diethyl ether between linear AE- and cyclic AE-degrading strains and phenetole between monoalkoxybenzene- and linear AE-degrading strains. Representatives of each group showed different substrate specificities and degradation pathways for the preferred substrates. Determining the rates of initial reactions and the initial metabolite(s) from whole cell biotransformation helped us to get information about the degradation pathways. Rhodococcus sp. strain DEE5311 and Rhodococcus rhodochrous strain 117 both were able to degrade anisole and phenetole through aromatic 2-monooxygenation to form 2-alkoxyphenols. In contrast, diethyl ether-oxidizing strain DEE5311 capable of degrading a broad range of linear AE, dibenzyl ether and monoalkoxybenzenes initially transformed anisole and phenetole to phenol via direct O-dealkylation. Compared to this, cyclic AE-degrading Rhodococcus sp. strain THF100 preferred tetrahydrofuran (265 ± 35 nmol min(-1)mg(-1) protein) to diethyl ether (<30), but it cannot oxidize bulkier AE than diethyl ether. Otherwise, 1,4-diethoxybenzene-degrading Rhodococcus sp. strain DEOB100 and Gordonia sp. strain DEOB200 transformed 1,3-/1,4-dialkoxybenzenes to 3-/4-alkoxyphenols by similar manners in the order of rates (nmol min(-1) mg(-1) protein): 1,4-diethoxybenzene (11.1 vs. 3.9)>1,4-dimethoxybenzene (1.6 vs. 2.6)>1,3-dimethoxybenzene (0.6 vs. 0.6). This study suggests that the AE-degrading Actinobacteria can orchestrate various substrate specificity responses to the degradation of various categories of AE pollutants in activated sludge communities.

  5. Preparation and characterization of polyion complex micelles with a novel thermosensitive poly(2-isopropyl-2-oxazoline) shell via the complexation of oppositely charged block ionomers.

    PubMed

    Park, Joon-Sik; Akiyama, Yoshitsugu; Yamasaki, Yuichi; Kataoka, Kazunori

    2007-01-01

    Novel thermosensitive polyion complex (PIC) micelles were prepared in an aqueous medium based on the complexation of a pair of oppositely charged block ionomers, poly(2-isopropyl-2-oxazoline)-b-poly(amino acid)s (PiPrOx-b-PAA), containing thermosensitive PiPrOx segments. The controlled synthesis of PiPrOx-b-PAA was achieved via the ring-opening anionic polymerization of N-carboxyanhydrides (NCA) of either eta-benzyloxycarbonyl-l-lysine (Lys(Z)-NCA) or beta-benzyl-l-aspartate (BLA-NCA) with omega-amino-functionalized PiPrOx macroinitiators and the subsequent deprotection reaction under acidic or basic conditions. Gel permeation chromatography (GPC) and 1H NMR spectroscopy revealed that the syntheses of two block ionomers, poly(2-isopropyl-2-oxazoline)-b-poly(l-lysine) [PiPrOx-P(Lys)] and poly(2-isopropyl-2-oxazoline)-b-poly(aspartic acid) [PiPrOx-P(Asp)], proceeded almost quantitatively to give samples with a narrow molecular weight distribution (Mw/Mn

  6. Cathodic delaminations of poly(phenyl ether ether ketone) (PEEK) coatings overlaid on zinc phosphate-deposited steels

    SciTech Connect

    Sugama, T.; Carciello, N.R. . Dept. of Applied Science)

    1993-12-10

    The melt-crystallized poly(phenyl) ether ether ketone (PEEK) polymer was overlaid on crystalline zinc phosphate (Zn [center dot] Ph) conversion coating-deposited and nondeposited cold-rolled steels at 400 C in air or in N[sub 2] environments. The ability of these coatings systems to protect the steel against corrosion was evaluated from the rate of cathodic delamination of the coating layer from the steel. Because the cathodic reaction, H[sub 2]O + 1/20[sub 2] + 2e[sup [minus

  7. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs...

  8. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs...

  9. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs...

  10. Catalytic cleavage of ether C-O bonds by pincer iridium complexes.

    PubMed

    Haibach, Michael C; Lease, Nicholas; Goldman, Alan S

    2014-09-15

    The development of efficient catalytic methods to cleave the relatively unreactive C-O bonds of ethers remains an important challenge in catalysis. Building on our group's recent work, we report the dehydroaryloxylation of aryl alkyl ethers using pincer iridium catalysts. This method represents a rare fully atom-economical method for ether C-O bond cleavage. PMID:25060043

  11. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  12. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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...

  13. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2010 CFR

    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...

  14. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  15. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  16. 40 CFR 721.9952 - Alkoxylated aliphatic diisocyanate allyl ether (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... allyl ether (generic). 721.9952 Section 721.9952 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.9952 Alkoxylated aliphatic diisocyanate allyl ether... identified generically as alkoxylated aliphatic diisocyanate allyl ether (PMN P-00-0353) is subject...

  17. 40 CFR 721.9952 - Alkoxylated aliphatic diisocyanate allyl ether (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... allyl ether (generic). 721.9952 Section 721.9952 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.9952 Alkoxylated aliphatic diisocyanate allyl ether... identified generically as alkoxylated aliphatic diisocyanate allyl ether (PMN P-00-0353) is subject...

  18. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs...

  19. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs...

  20. Structure-property study of keto-ether polyimides

    NASA Technical Reports Server (NTRS)

    Dezern, James F.; Croall, Catharine I.

    1991-01-01

    As part of an on-going effort to develop an understanding of how changes in the chemical structure affect polymer properties, an empirical study was performed on polyimides containing only ether and/or carbonyl connecting groups in the polymer backbone. During the past two decades the structure-property relationships in linear aromatic polyimides have been extensively investigated. More recently, work has been performed to study the effect of isomeric attachment of keto-ether polyimides on properties such as glass transition temperature and solubility. However, little work has been reported on the relation of polyimide structure to mechanical properties. The purpose of this study was to determine the effect of structural changes in the backbone of keto-ether polyimides on their mechanical properties, specifically, unoriented thin film tensile properties. This study was conducted in two stages. The purpose of the initial stage was to examine the physical and mechanical properties of a representative group (four) of polyimide systems to determine the optimum solvent and cure cycle requirements. These optimum conditions were then utilized in the second stage to prepare films of keto-ether polyimides which were evaluated for mechanical and physical properties. All of the polyimides were prepared using isomers of oxydianiline (ODA) and diaminobenzophenone (DABP) in combination with 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and 4,4'-oxydiphthalic anhydride (ODPA).

  1. 2,2\\',4,4\\'-Tetrabromodiphenyl ether (BDE-47)

    Integrated Risk Information System (IRIS)

    2,2 ' , 4,4 ' - Tetrabromodiphenyl ether ( BDE - 47 ) ; CASRN 5436 - 43 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health H

  2. 2,2\\',4,4\\',5-Pentabromodiphenyl ether (BDE-99)

    Integrated Risk Information System (IRIS)

    2,2 ' , 4,4 ' , 5 - Pentabromodiphenyl ether ( BDE - 99 ) ; CASRN 60348 - 60 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Hea

  3. Methyl substituted polyimides containing carbonyl and ether connecting groups

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Havens, Stephen J. (Inventor)

    1992-01-01

    Polyimides were prepared from the reaction of aromatic dianhydrides with novel aromatic diamines having carbonyl and ether groups connecting aromatic rings containing pendant methyl groups. The methyl substituent polyimides exhibit good solubility and form tough, strong films. Upon exposure to ultraviolet irradiation and/or heat, the methyl substituted polyimides crosslink to become insoluble.

  4. Lithium air batteries having ether-based electrolytes

    DOEpatents

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

    2016-10-25

    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.

  5. Li-air batteries having ether-based electrolytes

    DOEpatents

    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.

  6. POLYBROMINATED DIPHENYL ETHERS (PBDES) IN AMERICAN MOTHERS' MILK

    EPA Science Inventory

    No previous reports exist on polybrominated diphenyl ether (PBDE) congeners in individual American mothers' milk. This report on PBDEs is an extension of our previous studies on concentrations of dioxins, dibenzofurans, PCBs, and other chlorinated organics in human milk in a num...

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

    PubMed Central

    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 reaction system considerably hastened the process of chloro-organic product formation. Hydronium ions contribute to the formation of the reactive tert-butyl carbocation, which undergoes secondary reactions in the presence of reactive forms of chlorine and oxygen. Moreover, the effect of temperature on ETBE (tert-butylethyl ether) and MTBE (tert-butylmethyl ether) conversions was verified. The reactions of MTBE and ETBE oxychlorination were carried out at temperatures of 5°C, 20°C, and 35°C. PMID:19696944

  8. Selective, nickel-catalyzed hydrogenolysis of aryl ethers.

    PubMed

    Sergeev, Alexey G; Hartwig, John F

    2011-04-22

    Selective hydrogenolysis of the aromatic carbon-oxygen (C-O) bonds in aryl ethers is an unsolved synthetic problem important for the generation of fuels and chemical feedstocks from biomass and for the liquefaction of coal. Currently, the hydrogenolysis of aromatic C-O bonds requires heterogeneous catalysts that operate at high temperature and pressure and lead to a mixture of products from competing hydrogenolysis of aliphatic C-O bonds and hydrogenation of the arene. Here, we report hydrogenolyses of aromatic C-O bonds in alkyl aryl and diaryl ethers that form exclusively arenes and alcohols. This process is catalyzed by a soluble nickel carbene complex under just 1 bar of hydrogen at temperatures of 80 to 120°C; the relative reactivity of ether substrates scale as Ar-OAr>Ar-OMe>ArCH(2)-OMe (Ar, Aryl; Me, Methyl). Hydrogenolysis of lignin model compounds highlights the potential of this approach for the conversion of refractory aryl ether biopolymers to hydrocarbons. PMID:21512027

  9. Aqueous alkali metal hydroxide insoluble cellulose ether membrane

    NASA Technical Reports Server (NTRS)

    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.

  10. Synthesis and antitubercular activity of heterocycle substituted diphenyl ether derivatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite being an ancient disease, tuberculosis (TB) remains the leading single-agent infectious disease killer in the world. The emerging serious problem due to TB control and clinical management prompted us to synthesize novel series of heterocyclic substituted diphenyl ether derivatives and determ...

  11. Synthesis and Characterization of bis(Tetrahydrofurfuryl) Ether

    PubMed Central

    Stenger‐Smith, John D.; Baldwin, Lawrence; Chafin, Andrew

    2016-01-01

    Abstract Invited for this month's cover are researchers from the Naval Air Warfare Center Weapons Division (USA). The cover picture shows the elusive symmetric molecule bis(tetrahydrofurfuryl) ether (BTHFE) in the making. For more details, read the full text of the Communication at 10.1002/open.201600013. PMID:27547633

  12. Antiknock evaluation of hydrocarbons and ethers as aviation fuel components

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C

    1950-01-01

    The results of a NACA investigation conducted over a period of several years to evaluate the anti-knock characteristics of organic compounds are summarized. Included are data for 18 branched paraffins and olefins, 27 aromatics, and 22 ethers. The factors of performance investigated were blending characteristics, temperature sensitivity, lead response, and relation between molecular structure and antiknock ratings. Four engines were used.

  13. IRIS Toxicological Review of Pentabromodiphenyl Ether (Final Report)

    EPA Science Inventory

    The purpose of this Toxicological Review is to provide scientific support and rationale for the hazard and dose-response assessment in IRIS pertaining to chronic exposure to 2,2',4,4',5-pentabromodiphenyl ether. It is not intended to be a comprehensive treatise on the chemical...

  14. 42. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, NORTH WING, 1ST LEVEL, VIEW OF FILTERS AND BLOWERS FOR SOLVENT VAPORS FROM BUILDING NO. 527. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  15. 43. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, NORTH WING, 1ST LEVEL, LOOKING SOUTHWEST AT EQUIPMENT USED TO CONDENSE SOLVENT VAPORS TRANSMITTED BY SOLVENT RECOVERY DUCT FROM BUILDING NO. 527. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  16. 45. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. BUILDING NO. 519, ETHER AND ALCOHOL RECOVERY HOUSE, INTERIOR, CONTROL PANEL LEVEL (2ND DECK), LOOKING AT 'MIXED SOLVENT UNIT' CONTROL PANEL (LOOKING EAST). - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  17. [Antibacterial action of ether oils of some plants].

    PubMed

    Khaldun, A O

    2006-01-01

    Inhibitory effect of clove oil on Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Shigella dysenteriae and Candida albicans was detected. Mint ether oil had the high antibacterial action on S. aureus, however against other microorganisms mint oil had a reliably low effect then clove oil. Fennel oil had high antibacterial effect on C. albicans, and bactericidal action on S. typhimurium and S. dysenteriae. PMID:16830599

  18. AVOIDING HYDROLYSIS OF FUEL ETHER OXYGENATES DURING STATIC HEADSPACE ANALYSIS

    EPA Science Inventory

    A headspace autosampler, gas chromatograph and ion trap mass spectrometer (headspace GC/MS) were used for trace analysis of fuel oxygenates and related compounds and aromatics in water. A method has been developed for determination of methyl tert-butyl ether (MTBE), ethyl tert-b...

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

    PubMed

    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

  20. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Triethylene glycol monomethyl ether. 799.4440 Section 799.4440 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE...

  1. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Triethylene glycol monomethyl ether. 799.4440 Section 799.4440 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE...

  2. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Triethylene glycol monomethyl ether. 799.4440 Section 799.4440 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE...

  3. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 33 2013-07-01 2013-07-01 false Triethylene glycol monomethyl ether. 799.4440 Section 799.4440 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE...

  4. Synthesis and Characterization of bis(Tetrahydrofurfuryl) Ether.

    PubMed

    Stenger-Smith, John D; Baldwin, Lawrence; Chafin, Andrew; Goodman, Paul A

    2016-08-01

    Invited for this month's cover are researchers from the Naval Air Warfare Center Weapons Division (USA). The cover picture shows the elusive symmetric molecule bis (tetrahydrofurfuryl) ether (BTHFE) in the making. For more details, read the full text of the Communication at 10.1002/open.201600013. PMID:27547633

  5. Comparative acute and subchronic toxicity of ethylene glycol monopropyl ether and ethylene glycol monopropyl ether acetate.

    PubMed Central

    Katz, G V; Krasavage, W J; Terhaar, C J

    1984-01-01

    The acute toxicity of ethylene glycol monopropyl ether (EGPE) and ethylene glycol monopropyl ether acetate (EGPEA) was determined in a series of standardized tests. The oral LD50 in rats was 3089 and 9456 mg/kg EGPE and EGPEA, respectively. Skin irritation was slight following an occluded single dose application of either compound to the guinea pig abdomen. The dermal LD50 for guinea pigs was 1 to 5 mL/kg and greater than 20 mL/kg EGPE and EGPEA, respectively. EGPE produced a very weak positive sensitization response in one of five guinea pigs. No positive response was elicited when 10 guinea pigs were similarly challenged with EGPEA. EGPE produced transient moderate to severe eye irritation in rabbits while EGPEA produced slight eye irritation. Subchronic toxicity was determined in a series of oral and inhalation studies. Groups of 10 male rats were dosed with 15, 7.5, 3.75 or 1.88 mmole/kg EGPE and 30, 15 or 7.5 mmole/kg EGPEA by gavage 5 days/week for 6 weeks. Hemoglobinuria was seen at least once at all dose levels of both compounds. EGPE had little effect on feed consumption or body weight gain, while body weight gain was reduced in the two high dose groups exposed to EGPEA and feed consumption was reduced at all dose levels. Hematologic changes were seen at all dose levels of both compounds. Absolute and/or relative spleen weights were increased at all but the lowest EGPE dose level and at all EGPEA dose levels. Gross and histopathologic examinations revealed significant effects on the spleen of animals exposed to EGPE and on the spleen, liver, kidney and testes of animals exposed to EGPEA. The no-observed effect level (NOEL) for splenic changes was 1.88 mmole/kg EGPE. A NOEL for hematology was not established. The NOEL for liver and testicular changes were 15 and 7.5 mmole/kg EGPEA, respectively while a NOEL for hematologic, splenic and renal changes was not established. Groups of 10 rats (5M, 5F) were exposed to 800, 400, 200 or 100 ppm EGPE or EGPEA 6 hr

  6. Expandable Polyaryl-Ether-Ether-Ketone Spacers for Interbody Distraction in the Lumbar Spine

    PubMed Central

    Alimi, Marjan; Shin, Benjamin; Macielak, Michael; Hofstetter, Christoph P.; Njoku, Innocent; Tsiouris, Apostolos J.; Elowitz, Eric; Härtl, Roger

    2015-01-01

    Study Design Retrospective case series. Objective StaXx XD (Spine Wave, Inc., Shelton, CT, United States) is an expandable polyaryl-ether-ether-ketone (PEEK) wafer implant utilized in the treatment of lumbar degenerative disease. PEEK implants have been successfully used as interbody devices. Few studies have focused on expandable PEEK devices. The aim of the current study is to determine the radiographic and clinical outcome of expandable PEEK cages utilized for transforaminal lumbar interbody fusion in patients with lumbar degenerative diseases. Methods Forty-nine patients who underwent lumbar interbody fusion with implantation of expandable PEEK cages and posterior instrumentation were included. The clinical outcome was evaluated using the visual analog scale (VAS) and the Oswestry Disability Index (ODI). Radiographic parameters including disk height, foraminal height, listhesis, local disk angle of the index level/levels, regional lumbar lordosis, and graft subsidence were measured preoperatively, postoperatively, and at latest follow-up. Results At an average follow-up of 19.3 months, the minimum clinically important difference for the ODI and VAS back, buttock, and leg were achieved in 64, 52, 58, and 52% of the patients, respectively. There was statistically significant improvement in VAS back (6.42 versus 3.11, p < 0.001), VAS buttock (4.66 versus 1.97, p = 0.002), VAS leg (4.55 versus 1.96, p < 0.001), and ODI (21.7 versus 12.1, p < 0.001) scores. There was a significant increase in the average disk height (6.49 versus 8.18 mm, p = 0.037) and foraminal height (15.6 versus 18.53 mm, p = 0.0001), and a significant reduction in the listhesis (5.13 versus 3.15 mm, p = 0.005). The subsidence of 0.66 mm (7.4%) observed at the latest follow-up was not significant (p = 0.35). Conclusions Midterm results indicate that expandable PEEK spacers can effectively and durably restore disk and foraminal height and improve

  7. trans-Dichloridobis[dicyclo­hex­yl(4-isopropyl­phen­yl)phosphane-κP]platinum(II) acetone monosolvate

    PubMed Central

    Vuba, Bubele; Muller, Alfred

    2012-01-01

    The title compound, [PtCl2(C21H33P)2]·C3H6O, crystallizes with an accompanying acetone solvent mol­ecule. The metal atom shows a distorted square-planar coordination environment, with a P—Pt—P angle of 172.41 (3)° as the most prominent feature. Both isopropyl fragments were treated as disordered over two conformations with occupancy ratios of 0.55 (2):0.45 (2) and 0.58 (2):0.42 (2). The solvent mol­ecule was also disordered over two orientations in a 1:1 ratio. The crystal studied was a non-merohedral twin with a twin component of 32.4%. PMID:22259321

  8. New aspects in the phase behaviour of poly-N-isopropyl acrylamide: systematic temperature dependent shrinking of PNiPAM assemblies well beyond the LCST

    PubMed Central

    Bischofberger, Irmgard; Trappe, Veronique

    2015-01-01

    We investigate the phase behaviour of aqueous dispersions of poly-N-isopropyl acrylamide (PNiPAM) microgels above their lower critical solution temperature (LCST) and find that beyond a well-defined concentration the systems exhibit a peculiar behaviour: the microgels assemble into space-spanning gels that shrink in time while maintaining the shape of the container in which they have been formed. Over a wide range of concentrations this shrinking behaviour is independent of PNiPAM concentration, but systematically depends on temperature in a temperature range significantly exceeding the LCST. The overall shrinking characteristics are consistent with those expected for scaffolds made of materials that exhibit thermal contraction. However, for the PNiPAM assemblies contraction is irreversible and can be as large as 90%. Such characteristics disclose complex interactions between fully collapsed PNiPAM and water well beyond the LCST, the origin of which has yet to be elucidated. PMID:26493499

  9. The Sarin-like Organophosphorus Agent bis (isopropyl methyl)phosphonate Induces Apoptotic Cell Death and COX-2 Expression in SK-N-SH Cells.

    PubMed

    Arima, Yosuke; Yoshimoto, Kanji; Namera, Akira; Makita, Ryosuke; Murata, Kazuhiro; Nagao, Masataka

    2016-03-01

    Organophosphorus compounds, such as sarin, are highly toxic nerve agents that inhibit acetylcholinesterase (AChE), but not cholinesterase, via multiple mechanisms. Recent studies have shown that organophosphorus compounds increase cyclooxygenase-2 (COX-2) expression and induce neurotoxicity. In this study, we examined the toxicity of the sarin-like organophosphorus agent bis(isopropyl methyl)phosphonate (BIMP) and the effects of BIMP on COX-2 expression in SK-N-SH human neuroblastoma cells. Exposure to BIMP changed cell morphology and induced caspase-dependent apoptotic cell death accompanied by cleavage of caspase 3, caspase 9, and poly (ADP-ribose) polymerase (PARP). It also increased COX-2 expression, while pretreatment with a COX inhibitor, ibuprofen, decreased BIMP-dependent cell death and COX-2 expression in SK-N-SH cells. Thus, our findings suggest that BIMP induces apoptotic cell death and upregulates COX-2 expression. PMID:27348899

  10. Characterization of Free Surface-Bound and Entrapped Water Environments in Poly(N-Isopropyl Acrylamide) Hydrogels via 1H HRMAS PFG NMR Spectroscopy

    SciTech Connect

    Alam, Todd Michael; Childress, Kimberly Kay; Pastoor, Kevin; Rice, Charles

    2014-09-19

    We found that different water environments in poly(N-isopropyl acrylamide) (PNIPAAm) hydrogels are identified and characterized using 1H high resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR). Local water environments corresponding to a “free” highly mobile species, along with waters showing restricted dynamics are resolved in these swollen hydro-gels. For photo-initiated polymerized PNIPAAm gels, an additional entrapped water species is observed. Spin–spin R2 relaxation experiments support the argument of reduced mobility in the restricted and entrapped water species. Furthermore, by combining pulse field gradient techniques with HRMAS NMR it is possible to directly measure the self-diffusion rate for these different water environments. The behavior of the heterogeneous water environments through the lower critical solution temperature transition is described.

  11. Characterization of Free Surface-Bound and Entrapped Water Environments in Poly(N-Isopropyl Acrylamide) Hydrogels via 1H HRMAS PFG NMR Spectroscopy

    DOE PAGES

    Alam, Todd Michael; Childress, Kimberly Kay; Pastoor, Kevin; Rice, Charles

    2014-09-19

    We found that different water environments in poly(N-isopropyl acrylamide) (PNIPAAm) hydrogels are identified and characterized using 1H high resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR). Local water environments corresponding to a “free” highly mobile species, along with waters showing restricted dynamics are resolved in these swollen hydro-gels. For photo-initiated polymerized PNIPAAm gels, an additional entrapped water species is observed. Spin–spin R2 relaxation experiments support the argument of reduced mobility in the restricted and entrapped water species. Furthermore, by combining pulse field gradient techniques with HRMAS NMR it is possible to directly measure the self-diffusion rate for these differentmore » water environments. The behavior of the heterogeneous water environments through the lower critical solution temperature transition is described.« less

  12. Color indicator for supramolecular polymer chemistry: phenolphthalein-containing thermo- and pH-sensitive N-(Isopropyl)acrylamide copolymers and β-cyclodextrin complexation.

    PubMed

    Fleischmann, Carolin; Ritter, Helmut

    2013-07-12

    The copolymerization parameters of N-(isopropyl)acrylamide (1) and N-(2-hydroxy-5-(1-(4-hydroxyphenyl)-3-oxo-1,3-dihydroisobenzofuran-1-yl)benzyl)acrylamide (2) are determined. For both monomers, the homoaddition proceeds slightly faster than the heteroaddition step; however, the polymer formation occurs in a statistic fashion. Copolymers of different compositions are prepared and the cloud points are determined. Thereby, a significant influence of the concentration of monomer 2 and the pH value is found. For the first time, the complexation of polymer attached phenolphthalein by β-cyclodextrins is shown. Furthermore, it is possible to achieve a decomplexation by the addition of suitable guest molecules. Both procedures can be followed with the naked eye.

  13. N-isopropyl-(/sup 123/I)p-iodoamphetamine: single-pass brain uptake and washout; binding to brain synaptosomes; and localization in dog and monkey brain

    SciTech Connect

    Winchell, H.S.; Horst, W.D.; Braun, L.; Oldendorf, W.H.; Hattner, R.; Parker, H.

    1980-10-01

    The kinetics of N-isopropyl-p-(/sup 123/I)iodoamphetamine in rat brains were determined by serial measurements of brain uptake index (BUI) after intracarotid injection; also studied were its effects on amine uptake and release in rat's brain cortical synaptosomes; and its in vivo distribution in the dog and monkey. No specific localization in brain nuclei of the dog was seen, but there was progressive accumulation in the eyes. Rapid initial brain uptake in the ketamine-sedated monkey was noted, and further slow brain uptake occurred during the next 20 min but without retinal localization. High levels of brain activity were maintained for several hours. The quantitative initial single-pass clearance of the agent in the brain suggests its use in evaluation of regional brain perfusion. Its interaction with brain amine-binding sites suggests its possible application in studies of cerebral amine metabolism.

  14. trans-Dichloridobis{2-chloro-6-[(3-fluoro-benz-yl)amino]-9-isopropyl-9H-purine-κN (7)}platinum(II).

    PubMed

    Trávníček, Zdeněk; Starha, Pavel

    2013-06-01

    In the title compound, trans-[PtCl2(C15H15ClFN5)2], the Pt(II) atom, located on an inversion centre, is coordinated by the purine N atoms of the 2-chloro-6-[(3-fluoro-benz-yl)amino]-9-isopropyl-9H-purine ligands and two Cl atoms in a slightly distorted trans-square-planar coordination geometry [N-Pt-Cl angles = 89.91 (5) and 90.09 (5)°]. Weak intra-molecular N-H⋯Cl contacts occur. In the crystal, C-H⋯Cl and C-H⋯F contacts, as well as weak π-π stacking inter-actions [centroid-centroid distances = 3.5000 (11) and 3.6495 (12) Å] connect the mol-ecules into a three-dimensional architecture. PMID:23794993

  15. trans-Dichloridobis{2-chloro-6-[(3-fluoro­benz­yl)amino]-9-isopropyl-9H-purine-κN 7}platinum(II)

    PubMed Central

    Trávníček, Zdeněk; Štarha, Pavel

    2013-01-01

    In the title compound, trans-[PtCl2(C15H15ClFN5)2], the PtII atom, located on an inversion centre, is coordinated by the purine N atoms of the 2-chloro-6-[(3-fluoro­benz­yl)amino]-9-isopropyl-9H-purine ligands and two Cl atoms in a slightly distorted trans-square-planar coordination geometry [N—Pt—Cl angles = 89.91 (5) and 90.09 (5)°]. Weak intra­molecular N—H⋯Cl contacts occur. In the crystal, C—H⋯Cl and C—H⋯F contacts, as well as weak π–π stacking inter­actions [centroid–centroid distances = 3.5000 (11) and 3.6495 (12) Å] connect the mol­ecules into a three-dimensional architecture. PMID:23794993

  16. New aspects in the phase behaviour of poly-N-isopropyl acrylamide: systematic temperature dependent shrinking of PNiPAM assemblies well beyond the LCST

    NASA Astrophysics Data System (ADS)

    Bischofberger, Irmgard; Trappe, Veronique

    2015-10-01

    We investigate the phase behaviour of aqueous dispersions of poly-N-isopropyl acrylamide (PNiPAM) microgels above their lower critical solution temperature (LCST) and find that beyond a well-defined concentration the systems exhibit a peculiar behaviour: the microgels assemble into space-spanning gels that shrink in time while maintaining the shape of the container in which they have been formed. Over a wide range of concentrations this shrinking behaviour is independent of PNiPAM concentration, but systematically depends on temperature in a temperature range significantly exceeding the LCST. The overall shrinking characteristics are consistent with those expected for scaffolds made of materials that exhibit thermal contraction. However, for the PNiPAM assemblies contraction is irreversible and can be as large as 90%. Such characteristics disclose complex interactions between fully collapsed PNiPAM and water well beyond the LCST, the origin of which has yet to be elucidated.

  17. Organometallic complexes of bulky, optically active, C3-symmetric tris(4S-isopropyl-5,5-dimethyl-2-oxazolinyl)phenylborate (ToP*)

    DOE PAGES

    Xu, Songchen; Magoon, Yitzhak; Reinig, Regina R.; Schmidt, Bradley M.; Ellern, Arkady; Sadow, Aaron D.

    2015-07-16

    A bulky, optically active monoanionic scorpionate ligand, tris(4S-isopropyl-5,5-dimethyl-2-oxazolinyl)phenylborate (ToP*), is synthesized from the naturally occurring amino acid l-valine as its lithium salt, Li[ToP*] (1). That compound is readily converted to the thallium complex Tl[ToP*] (2) and to the acid derivative H[ToP*] (3). Group 7 tricarbonyl complexes ToP*M(CO)3 (M = Mn (4), Re (5)) are synthesized by the reaction of MBr(CO)5 and Li[ToP*] and are crystallographically characterized. The νCO bands in their infrared spectra indicate that π back-donation in the rhenium compounds is greater with ToP* than with non-methylated tris(4S-isopropyl-2-oxazolinyl)phenylborate (ToP). The reaction of H[ToP*] and ZnEt2 gives ToP*ZnEt (6), whilemore » ToP*ZnCl (7) is synthesized from Li[ToP*] and ZnCl2. The reaction of ToP*ZnCl and KOtBu followed by addition of PhSiH3 provides the zinc hydride complex ToP*ZnH (8). In this study, compound 8 is the first example of a crystallographically characterized optically active zinc hydride. We tested its catalytic reactivity in the cross-dehydrocoupling of silanes and alcohols, which provided Si-chiral silanes with moderate enantioselectivity.« less

  18. Binding of ether and carbonyl oxygens to lithium ion

    SciTech Connect

    Blint, R.J.

    1994-12-31

    The electrolyte for a lithium battery is a lithium salt (e.g. lithium Perchlorate) dissolved in an organic solvent or a mixture of organic solvents. The conductivity in these electrolytes is ionic and needs to be as high as possible to efficiently remove energy from the battery. The diffusion coefficient of the solvated ion in liquid electrolytes is inversely dependent on the radius of the salvation sphere. Consequently conductivity will increase with a decrease in the size of the salvation shell. The size of the salvation shell is determined by the size and coordination number of the solvent molecules. The types of organic solvents in electrolytes used in lithium battery applications are usually differentiated based on their perceived solvation properties. These solvents are often small, oxygen containing organic molecules which move with the Li{sup +} ions. This paper calculates the binding energies of some of these solvents to Li{sup +} using molecular quantum mechanics (MQM) techniques. The binding energies of the various solvents to Li{sup +} may determine which solvents will be preferentially bound to the ion. In liquid organic electrolytes, then, it will be the identity of the solvent and the coordination number which most affect the conductivity; the binding energies determine both of these properties. Carbonyl oxygens which occur in formaldehyde, acetaldehyde, acetone, ethylene carbonate and propylene carbonate have different Li{sup +} bonding properties than do the ether oxygens which occur in water, dimethyl ether and diethyl ether. Polymer solvents for the lithium salts such as the polyethers have chains which are too long to move with the binding energies then serve as the basis for a different Li{sup +} transport. Dimethyl ether and diethyl ether serve both as solvents and models for the polyethers.

  19. Use of fluorinated polybrominated diphenyl ethers and simplified cleanup for the analysis of polybrominated diphenyl ethers in house dust

    EPA Science Inventory

    A simple, cost-effective method is described for the analysis of polybrominated diphenyl ethers (PBDEs) in house dust using pressurized fluid extraction, cleanup with modified silica solid phase extraction tubes, and fluorinated internal standards. There are 14 PBDE congeners inc...

  20. A gemini quaternary ammonium poly (ether ether ketone) anion-exchange membrane for alkaline fuel cell: design, synthesis, and properties.

    PubMed

    Si, Jiangju; Lu, Shanfu; Xu, Xin; Peng, Sikan; Xiu, Ruijie; Xiang, Yan

    2014-12-01

    To reconcile the tradeoff between conductivity and dimensional stability in AEMs, a novel Gemini quaternary ammonium poly (ether ether ketone) (GQ-PEEK) membrane was designed and successfully synthesized by a green three-step procedure that included polycondensation, bromination, and quaternization. Gemini quaternary ammonium cation groups attached to the anti-swelling PEEK backbone improved the ionic conductivity of the membranes while undergoing only moderate swelling. The grafting degree (GD) of the GQ-PEEK significantly affected the properties of the membranes, including their ion-exchange capacity, water uptake, swelling, and ionic conductivity. Our GQ-PEEK membranes exhibited less swelling (≤ 40 % at 25-70 °C, GD 67 %) and greater ionic conductivity (44.8 mS cm(-1) at 75 °C, GD 67 %) compared with single quaternary ammonium poly (ether ether ketone). Enhanced fuel cell performance was achieved when the GQ-PEEK membranes were incorporated into H2 /O2 single cells. PMID:25346412

  1. A Caenorhabditis elegans model for ether lipid biosynthesis and function[S

    PubMed Central

    Shi, Xun; Tarazona, Pablo; Brock, Trisha J.; Browse, John; Feussner, Ivo; Watts, Jennifer L.

    2016-01-01

    Ether lipids are widespread in nature, and they are structurally and functionally important components of membranes. The roundworm, Caenorhabditis elegans, synthesizes numerous lipid species containing alkyl and alkenyl ether bonds. We isolated C. elegans strains carrying loss-of-function mutations in three genes encoding the proteins required for the initial three steps in the ether lipid biosynthetic pathway, FARD-1/FAR1, ACL-7/GNPAT, and ADS-1/AGPS. Analysis of the mutant strains show that they lack ether lipids, but possess the ability to alter their lipid composition in response to lack of ether lipids. We found that increases in de novo fatty acid synthesis and reduction of stearoyl- and palmitoyl-CoA desaturase activity, processes that are at least partially regulated transcriptionally, mediate the altered lipid composition in ether lipid-deficient mutants. Phenotypic analysis demonstrated the importance of ether lipids for optimal fertility, lifespan, survival at cold temperatures, and resistance to oxidative stress.Caenorhabditis PMID:26685325

  2. Investigation of Volumetric Properties of Some Glycol Ethers Using a Simple Equation of State

    NASA Astrophysics Data System (ADS)

    Moosavi, M.; Goharshadi, E. K.

    2006-09-01

    In this work, a simple equation of state (EoS) has been used to predict the density and other thermodynamic properties such as the isobaric expansion coefficient, α P , the isothermal compressibility, κ T , and the internal pressure, P i , of six glycol ethers including diethylene glycol monobutyl ether (DEGBE), propylene glycol propyl ether (PGPE), diethylene glycol monomethyl ether (DEGME), diethylene glycol monoethyl ether (DEGEE), triethylene glycol dimethyl ether (TriEGDME), and tetraethylene glycol dimethyl ether (TEGDME) at different temperatures and pressures. A comparison with literature experimental data has been made. Additionally, statistical parameters between experimental and calculated densities for the GMA EoS and four other EoSs (Soave Redlich Kwong, Peng Robinson, Soave Redlich Kwong with volume translation, and Patel Teja) indicate the superiority of the GMA EoS.

  3. Catalytic and electrocatalytic hydrogenolysis of brominated diphenyl ethers.

    PubMed

    Bonin, Pascale M L; Edwards, Patrick; Bejan, Dorin; Lo, Chun Chi; Bunce, Nigel J; Konstantinov, Alexandre D

    2005-02-01

    Polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental contaminants due to their use as additive flame-retardants. Conventional catalytic hydrogenolysis in methanol solution and electrocatalytic hydrogenolysis in aqueous methanol were examined as methods for debrominating mono- and di-bromodiphenyl ethers, as well as a commercial penta-PBDE mixture, in each case using palladium on alumina as the catalyst. Electrocatalytic hydrogenolysis employed a divided flow-through batch cell, with reticulated vitreous carbon cathodes and IrO2/Ti dimensionally stable anodes. Both methods gave efficient sequential debromination, with essentially complete removal of bromine from the PBDEs, but the electrocatalytic method was limited by the poor solubility of PBDEs in aqueous methanol. PMID:15639268

  4. Poly(hydroxy amino ethers): Novel high-barrier thermoplastics

    SciTech Connect

    Silvis, H.C.; Brown, C.N.; Kram, S.L.; White, J.E.

    1995-12-31

    A visible trend in the area of food and beverage packaging is the ever increasing substitution of plastics for materials such as glass and metal. This research details the synthesis and properties of a new class of high barrier thermoplastics, namely poly(hydroxy amino ethers) (PHAE) prepared from stoichiometric reactions of primary amines or bis-sec-diamines with aromatic diglycidyl ethers in solution or in the melt. These polymers are true high molecular weight thermoplastics that can be fabricated by a variety of conventional processing techniques. The oxygen transmission rates of these polymers range from moderate (<5 BU) to very low (<0.1 BU), depending on the backbone structure of the PHAE in question. These extraordinary barrier properties are the consequence of a high degree of interchain cohesion due to hydrogen bonding interactions. The effect of polymer structure on oxygen transmission rate, glass transition temperature, and physical properties has been studied in detail.

  5. Synthesis and Characterization of bis(Tetrahydrofurfuryl) Ether

    PubMed Central

    Stenger‐Smith, John D.; Baldwin, Lawrence; Chafin, Andrew

    2016-01-01

    Abstract Despite the availability of a large number of alkyl tetrahydrofurfuryl ethers that have a wide range of applications, pure bis(tetrahydrofurfuryl) ether (BTHFE) has not been previously synthesized. Here, we report the synthesis of BTHFE (consisting of the RR, SS, and meso stereoisomers) at greater than 99 % purity from tetrahydrofurfuryl alcohol, using (tetrahydrofuran‐2‐yl)methyl methanesulfonate as an intermediate. Additionally, we demonstrate that BTHFE can be used as a non‐volatile solvent in poly(3,4‐propylenedioxythiophene)‐based supercapacitors. Supercapacitor devices employing solutions of the ionic liquid 1‐ethyl‐3‐methyl‐imidizolium bis(trifluoromethylsulfonyl)imide in BTHFE display similar performances to those prepared by using the neat ionic liquid as an electrolyte, although solution‐based devices exhibit a somewhat higher resistance. PMID:27547636

  6. Radical arylation of phenols, phenyl ethers, and furans.

    PubMed

    Wetzel, Alexander; Pratsch, Gerald; Kolb, Roman; Heinrich, Markus R

    2010-02-22

    Radical arylations of para-substituted phenols and phenyl ethers proceeded with good regioselectivity at the ortho position with respect to the hydroxy or alkoxy group. The reactions were conducted with arenediazonium salts as the aryl radical source, titanium(III) chloride as the reductant, and diluted hydrochloric acid as the solvent. Substituted biaryls were obtained from hydroxy- and alkoxy-substituted benzylamines, phenethylamines, and aromatic amino acids. The methodology described offers a fast, efficient, and cost-effective new access to diversely functionalized biphenyl alcohols and ethers. Free phenolic hydroxy groups, aromatic and aliphatic amines, as well as amino acid substructures, are well tolerated. Two examples for the applicability of the methodology are the partial synthesis of a beta-secretase inhibitor and the synthesis of a calcium-channel modulator. PMID:20066707

  7. Ether and ester derivatives of the perborate icosahedron

    DOEpatents

    Hawthorne, M. Frederick; Peymann, Toralf; Maderna, Andreas

    2003-12-16

    New boron icosahedral ethers and esters formed from Cs.sub.2 [closo-B.sub.12 (OH).sub.12 ],; Cs[closo-1-H-1-CB.sub.11 (OH).sub.11 ]; and closo-1,12-H.sub.2 -1,12-C.sub.2 B.sub.10 (OH).sub.10 are disclosed. Also set forth are their preparation by reacting the icosahedral boranes [closo-B.sub.12 H.sub.12 ].sup.2-, [closo-1-CB.sub.11 H.sub.12 ].sup.- and closo-1,12-(CH.sub.2 OH).sub.2 -1,12-C.sub.2 B.sub.10 H.sub.10 with an acid anhdride or acid chloride to form the ester or an alkylating agent to form the ether.

  8. Synthesis of Ethers via Reaction of Carbanions and Monoperoxyacetals

    PubMed Central

    2015-01-01

    Although transfer of electrophilic alkoxyl (“RO+”) from organic peroxides to organometallics offers a complement to traditional methods for etherification, application has been limited by constraints associated with peroxide reactivity and stability. We now demonstrate that readily prepared tetrahydropyranyl monoperoxyacetals react with sp3 and sp2 organolithium and organomagnesium reagents to furnish moderate to high yields of ethers. The method is successfully applied to the synthesis of alkyl, alkenyl, aryl, heteroaryl, and cyclopropyl ethers, mixed O,O-acetals, and S,S,O-orthoesters. In contrast to reactions of dialkyl and alkyl/silyl peroxides, the displacements of monoperoxyacetals provide no evidence for alkoxy radical intermediates. At the same time, the high yields observed for transfer of primary, secondary, or tertiary alkoxides, the latter involving attack on neopentyl oxygen, are inconsistent with an SN2 mechanism. Theoretical studies suggest a mechanism involving Lewis acid promoted insertion of organometallics into the O–O bond. PMID:26560686

  9. Synthesis and Characterization of bis(Tetrahydrofurfuryl) Ether.

    PubMed

    Stenger-Smith, John D; Baldwin, Lawrence; Chafin, Andrew; Goodman, Paul A

    2016-08-01

    Despite the availability of a large number of alkyl tetrahydrofurfuryl ethers that have a wide range of applications, pure bis(tetrahydrofurfuryl) ether (BTHFE) has not been previously synthesized. Here, we report the synthesis of BTHFE (consisting of the RR, SS, and meso stereoisomers) at greater than 99 % purity from tetrahydrofurfuryl alcohol, using (tetrahydrofuran-2-yl)methyl methanesulfonate as an intermediate. Additionally, we demonstrate that BTHFE can be used as a non-volatile solvent in poly(3,4-propylenedioxythiophene)-based supercapacitors. Supercapacitor devices employing solutions of the ionic liquid 1-ethyl-3-methyl-imidizolium bis(trifluoromethylsulfonyl)imide in BTHFE display similar performances to those prepared by using the neat ionic liquid as an electrolyte, although solution-based devices exhibit a somewhat higher resistance. PMID:27547636

  10. 2' and 3' Carboranyl uridines and their diethyl ether adducts

    DOEpatents

    Soloway, Albert H.; Barth, Rolf F.; Anisuzzaman, Abul K.; Alam, Fazlul; Tjarks, Werner

    1992-01-01

    There is disclosed a process for preparing carboranyl uridine nucleoside compounds and their diethyl ether adducts, which exhibit a tenfold increase in boron content over prior art boron containing nucleoside compounds. Said carboranyl uridine nucleoside compounds exhibit enhanced lipophilicity and hydrophilic properties adequate to enable solvation in aqueous media for subsequent incorporation of said compounds in methods for boron neutron capture therapy in mammalian tumor cells.

  11. Secondary Li battery incorporating 12-Crown-4 ether

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, Ganesan (Inventor); Distefano, Salvador (Inventor)

    1992-01-01

    A rechargeable lithium battery which utilizes a polyethylene oxide (PEO) solid polymeric electrolyte complexed with a lithium salt is disclosed. The conductivity is increased an order of magnitude and interfacial charge transfer resistance is substantially decreased by incorporating a minor amount of 12-Crown-4 ether in the PEO-lithium salt solid electrolyte film. Batteries containing the improved electrolyte permit operation at a lower temperature with improved efficiency.

  12. Decabromodiphenyl ether in the rat: absorption, distribution, metabolism, and excretion.

    PubMed

    Morck, Anna; Hakk, Heldur; Orn, Ulrika; Klasson Wehler, Eva

    2003-07-01

    Among the group of polybrominated diphenyl ethers used as flame-retardants, the fully brominated diphenyl ether, decabromodiphenyl ether (decaBDE), is the most commonly used. Despite the large usage of decaBDE, neither the metabolic pathways nor the absorption have been addressed, and there are very few studies on its toxicology. In this work, it is shown that after a single oral dose of 14C-labeled decaBDE to rats, at least 10% of the decaBDE dose is absorbed. The major excretion route in conventional rats is via feces that contained 90% of the decaBDE dose. The excretion in bile was close to 10% of the dose and represented mainly metabolites. It cannot be excluded that greater than 10% of the oral dose had been absorbed since 65% of the radioactivity excreted in feces was metabolites. The highest concentrations on a lipid weight basis were found in plasma and blood-rich tissues, and the adipose tissue had the lowest concentration of decaBDE. After derivatization of a phenolic fraction, gas chromatography-mass spectrometry (GC/MS) analyses indicated that metabolites with five to seven bromine atoms had formed, and they possessed a guaiacol structure (a hydroxy and a methoxy group) in one of the rings. In addition, traces of nonabrominated diphenyl ethers and monohydroxylated metabolites were found by GC/MS. Metabolites, characterized by their chemical properties, were interpreted to be covalently bound to macromolecules, either proteins or lipids. In addition, water solubility was suggested. The metabolic pathway was indicated to include a reactive intermediate. PMID:12814967

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

    NASA Astrophysics Data System (ADS)

    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. Intracluster ion-molecule reactions of Ti+ with ether clusters

    NASA Astrophysics Data System (ADS)

    Koo, Young-Mi; Kim, Min-Kyung; Jung, Kwang-Woo

    2005-05-01

    The intracluster ion-molecule reactions of Ti+(CH3OR)n (R = CH3, n-C3H7, n-C4H9, t-C4H9) complexes produced by the mixing of laser-vaporized plasmas and pulsed supersonic beams were investigated using a reflectron time-of-flight mass spectrometer (RTOFMS). The reactions of Ti+ with dimethyl ether clusters were found to be dominated by the CH3 elimination reaction, which produces Ti+(OCH3)m(CH3OCH3)n clusters (m = 1-3). The mass spectra resulting from the reactions of Ti+ with the other ether clusters indicate the formation of major sequences of heterocluster ions with the formula Ti+(OCH3)x(OR)y(CH3OR)n, where x = 1-3 and y = 0-2. These sequences are attributed to the insertion of Ti+ ions into the CO bonds of the ether molecules within the heteroclusters, followed by alkyl radical elimination. The prevalence of radical elimination of longer alkyl groups rather than of CH3 radicals suggests that R elimination from the [CH3OTi+R] intermediate is the preferred decomposition pathway after the selective insertion of a Ti+ ion into the CO bond of an OR group. Our results also indicate that consecutive insertions of a Ti+ ion can occur for up to three precursor molecules. The experiments also show that the molecular eliminations of H2 and alkanes, resulting from CH and CC bond insertion, respectively, play an increasingly important role as the size of the alkyl group (R) in the ether molecule increases. The reaction energetics and the formation mechanisms of the observed heterocluster ions are also discussed.

  15. Determination of bisphenol diglycidyl ethers in topical dosage forms.

    PubMed

    Søeborg, Tue; Hansen, Steen Honoré; Halling-Sørensen, Bent

    2006-02-13

    A method involving extraction and LC-ESI-MS-MS detection of BADGE, BFDGE, BADGE*H2O, BADGE*2H2O, BADGE*HCl, BADGE*H2O*HCl, BADGE.2HCl and BFDGE*2HCl in aqueous cream was developed and validated. Initially, empty internally lacquered aluminum container closure systems were extracted with isopropanol as an attempt to estimate the upper limit of extractable bisphenol diglycidyl ethers present in lacquer. Six of the eight potential bisphenol diglycidyl ethers were quantified. In an accelerated experiment, on aqueous cream stored in lacquered aluminum tubes at 70 degrees C, all derivatives except BADGE*2HCl and BFDGE*2HCl were extracted from cream samples and quantified as an attempt to estimate the upper limit of compounds leaching to the cream. Detection limits were from 0.3+/-0.2 to 3.4+/-0.7 microgl(-1). Recoveries were determined for all compounds at three concentration levels (mean 63+/-6%). Mean inter-day and mean intra-day precision was 7+/-2 and 13+/-6%, respectively. Three commercially available creams were obtained from a local community pharmacy and analysed for bisphenol diglycidyl ethers. BADGE, BADGE*H2O, BADGE*2H2O and BADGE*H2O*HCl were detected and quantified. In conclusion, the developed method allows for the extraction and detection of bisphenol diglycidyl ethers originating from the epoxy phenol lacquer used in aluminum tubes. This study does not indicate that they leach into aqueous cream in significant amounts under normal storage conditions.

  16. Thiophenyl ether disiloxanes and trisiloxanes useful as lubricant fluids

    NASA Technical Reports Server (NTRS)

    Bilow, N.; Akawie, R. I. (Inventor)

    1974-01-01

    The characteristics of organosilicon compounds for lubrication under extreme conditions are discussed. The substances considered are thiophenyl ether disiloxanes and trisiloxanes. These substances have low pour points and a high degree of radiation resistance. Substitution of sulfur for the phenoxy group oxygen of either siloxane compounds has been found to result in a marked improvement in lubricity. The chemical formulas of the organic compounds are presented.

  17. A constitutive model of polyether-ether-ketone (PEEK).

    PubMed

    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

  18. Synthesis and biological evaluation of 12 allenic aromatic ethers.

    PubMed

    Wang, San-Yong; Mao, Wei-Wei; She, Zhi-Gang; Li, Chun-Rong; Yang, Ding-Qiao; Lin, Yong-Cheng; Fu, Li-Wu

    2007-05-15

    Twelve allenic aromatic ethers, some of them are natural products isolated from the mangrove fungus Xylaria sp. 2508 in the South China Sea, were synthesized. Their antitumor activities against KB and KBv200 cells were determined. All these compounds demonstrated cytotoxic potential, ranging from weak to strong activity. The analysis of structure-activity relationships suggested that the introduction of allenic moiety could generate or enhance cytotoxicity of these phenol compounds.

  19. The interactions of water and perfluorodiethyl ether on Ru(100)

    SciTech Connect

    Leavitt, P.

    1990-09-21

    We have studied the interactions of water and perfluorodiethyl ether on Ru(100) in order to model the effects of surface structure and humidity on the bonding and decomposition of perfluoroalkyl ether lubricants with metal surfaces. In order to understand the interactions on Ru(100), we have first investigated the interactions of each of these adsorbates alone on the clean surface. The interactions of water with Ru(100) have been studied using both thermal desorption spectroscopy (TDS) and electron energy loss spectroscopy (EELS). From these studies we conclude that a small amount of water dissociates on this surface (5--10% of a monolayer), but water is adsorbed in a predominantly molecular form on this surface with an increasing degree of hydrogen-bonding with increasing coverage. The effects of hydrogen and oxygen coadsorption on the interactions of water with this surface have also been studied using TDS. Finally, the interactions of coadsorbed water and perfluorodiethyl ether on Ru(100) have been investigated using TDS.

  20. Microbial degradation of decabromodiphenyl ether (DBDE) in soil slurry microcosms.

    PubMed

    Chou, Hsi-Ling; Hwa, Mei-Yin; Lee, Yao-Chuan; Chang, Yu-Jie; Chang, Yi-Tang

    2016-03-01

    Decabromodiphenyl ether (DBDE), which has been identified as an endocrine disrupting compound, is used as brominated flame retardant, and this can result in serious bioaccumulation within ecological systems. The objective of this study was to explore DBDE bioremediation (25 mg/kg) using laboratory scale soil slurry microcosms. It was found that effective biodegradation of DBDE occurred in all microcosms. Various biometabolites were identified, namely polybrominated diphenyl ethers congeners and hydroxylated brominated diphenyl ether. Reductive debrominated products such as tri-BDE to hepta-BDE congeners were also detected, and their total concentrations ranged from 77.83 to 91.07 ng/g. The mechanism of DBDE biodegradation in soil slurry microcosms is proposed to consist of a series of biological reactions involving hydroxylation and debromination. Catechol 2,3-oxygenase genes, which are able to bring about meta-cleavage at specific unbrominated locations in carbon backbones, were identified as present during the DBDE biodegradation. No obvious effect on the ecological functional potential based on community-level physiological profiling was observed during DBDE biodegradation, and one major facultative Pseudomonas sp. (99 % similarity) was identified in the various soil slurry microcosms. These findings provide an important basis that should help environmental engineers to design future DBDE bioremediation systems that use a practical microcosm system. A bacterial-mixed culture can be selected as part of the bioaugmentation process for in situ DBDE bioremediation. A soil/water microcosm system can be successfully applied to carry out ex situ DBDE bioremediation. PMID:26561328

  1. Mode of Action Studies on Nitrodiphenyl Ether Herbicides 1

    PubMed Central

    Bowyer, John R.; Hallahan, Beverly J.; Camilleri, Patrick; Howard, Joy

    1989-01-01

    The nitrodiphenyl ether herbicide 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitroacetophenone oxime-o-(acetic acid, methyl ester) (DPEI) induces light- and O2-dependent lipid peroxidation and chlorophyll (Chl) bleaching in the green alga Scenedesmus obliquus. Under conditions of O2-limitation, these effects are diminished by prometyne and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), both inhibitors of photosynthetic electron transport. Mutants in which photosynthetic electron transport is blocked are also resistant to DPEI under conditions of O2-limitation. Light- and O2-dependent lipid peroxidation and Chl bleaching are also induced by 5-[2-chloro-4-(trifluoromethyl)phenoxy]-3-methoxyphthalide (DPEII), a diphenyl ether whose redox properties preclude reduction by photosystem I. However, these effects of DPEII are also inhibited by DCMU. Under conditions of high aeration, DCMU does not protect Scenedesmus cells from Chl bleaching induced by DPEI, but does protect against paraquat. DPEI, but not paraquat, induces tetrapyrrole formation in treated cells in the dark. This is also observed in a mutant lacking photosystem I but is suppressed under conditions likely to lead to O2 limitation. Our results indicate that, in contrast to paraquat, the role of photosynthetic electron transport in diphenyl ether toxicity in Scenedesmus is not to reduce the herbicide to a radical species which initiates lipid peroxidation. Its role is probably to maintain a sufficiently high O2 concentration, through water-splitting, in the algal suspension. PMID:16666600

  2. Microbial degradation of 4-monobrominated diphenyl ether with anaerobic sludge.

    PubMed

    Shih, Yang-hsin; Chou, Hsi-Ling; Peng, Yu-Huei

    2012-04-30

    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 H(2) 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.

  3. Radical addition-initiated domino reactions of conjugated oxime ethers.

    PubMed

    Ueda, Masafumi

    2014-01-01

    The application of conjugated oxime ethers to the synthesis of complex chemical scaffolds using domino radical reactions has been described in detail. The triethylborane-mediated hydroxysulfenylation reaction allows for the regioselective construction of a carbon-sulfur bond and a carbon-oxygen bond in a single operation for the formation of β-hydroxy sulfides. This reaction proceeds via a radical pathway involving regioselective thiyl addition and the subsequent trapping of the resulting α-imino radical with O₂, where the imino group enhances the stability of the intermediate radical. Hydroxyalkylation reactions that occur via a carbon radical addition reaction followed by the hydroxylation of the resulting N-borylenamine with O₂ have also been developed. We investigated sequential radical addition aldol-type reactions in detail to explore the novel domino reactions that occur via the generation of N-borylenamine. The radical reaction of a conjugated oxime ether with triethylborane in the presence of an aldehyde affords γ-butyrolactone via sequential processes including ethyl radical addition, the generation of N-borylenamine, an aldol-type reaction with an aldehyde, and a lactonization reaction. A novel domino reaction has also been developed involving the [3,3]-sigmatropic rearrangement of N-boryl-N-phenoxyenamine. The triethylborane-mediated domino reactions of O-phenyl-conjugated oxime ethers afforded the corresponding benzofuro[2,3-b]pyrrol-2-ones via a radical addition/[3,3]-sigmatropic rearrangement/cyclization/lactamization cascade.

  4. Microbial degradation of 4-monobrominated diphenyl ether with anaerobic sludge.

    PubMed

    Shih, Yang-hsin; Chou, Hsi-Ling; Peng, Yu-Huei

    2012-04-30

    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 H(2) 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. PMID:22370205

  5. Thermolysis of surface-immobilized phenethyl phenyl ether

    SciTech Connect

    Britt, P.F.; Buchanan, A.C. III; Hitsman, V.M.

    1991-01-01

    Our research has focused on modeling the constraints on free-radical reactions that might be imposed in coal as a consequence of its cross-linked macromolecular structure by covalently bonding diphenylalkanes to an inert silica surface. A surface-immobilized phenethyl phenyl ether ({approx}PhCH{sub 2}CH{sub 2}POh, or {approx}PPE-3) has been prepared as a model for ether linkages in lignin by the condensation of p-HOPhCH{sub 2}CH{sub 2}OPh with the surface hydroxyls of a high purity fumed silica. Thermolysis of {approx}PPE-3 at saturation surface coverage at 375{degree}C produces {approx}PhCH = CH{sub 2} and PhOH as the major products which are consistent with the proposed free-radical chain mechanism for the decomposition of fluid-phase phenethyl phenyl ether. However, significant quantities of {approx}PhCH{sub 3} and PhCHO (ca. 18% of the products) are produced indicating the emergence of a new reaction pathway on the surface. The mechanism for the decomposition of {approx}PPE-3 will be discussed in light of this new information. 18 refs., 1 fig.

  6. Developmental toxicity of diphenyl ether herbicides in birds

    USGS Publications Warehouse

    Hoffman, D.J.; Rattner, B.A.; Bunck, C.M.

    1991-01-01

    Diphenyl ether herblcldes, includlng nitrofen, have been identified as mammalian teratogens and cause perinatal mortality. American kestrel (Falco sparverius) nestlings were orally dosed for 10 days w1th 5 ul/g of corn oil (controls) or one of the diphenyl ether herbicides (nitrofen, bifenox, or oxyfluorofen). At 500 mg/kg, nitrofen resulted in complete mortality, bifenox in high (66%) mortality, and oxyfluorofen in no mortality. Nitrofen, at 250 mg/kg, reduced nestling growth, as reflected by decreased body weight and bone length. Bifenox at 250 mg/kg had less effect on growth than nitrofen but crown rump, humerus, radiusulna and femur lengths were significantly less than controls. Liver welght (percent of body welght) increased with 50 mg/kg nitrofen. Other manifestations of hepatotoxicity following nitrofen ingestion included increased hepatic GSH peroxidase activity with 0 mg/kg nitrofen, and increased plasma enzyme activities for ALT, AST. and LDHL with 250 mg/kg. Blfenox lngestion (50 mg/kg) resulted in increased hepatlc GSH peroxidase activity. Nitrofen exposure increased total plasma thyroxlne (T4) concentratlon. These findings suggest that altricial nestllng kestrels are more sensitive to diphenyl ether herbicides than precocial young or adult birds.

  7. Microbial degradation of decabromodiphenyl ether (DBDE) in soil slurry microcosms.

    PubMed

    Chou, Hsi-Ling; Hwa, Mei-Yin; Lee, Yao-Chuan; Chang, Yu-Jie; Chang, Yi-Tang

    2016-03-01

    Decabromodiphenyl ether (DBDE), which has been identified as an endocrine disrupting compound, is used as brominated flame retardant, and this can result in serious bioaccumulation within ecological systems. The objective of this study was to explore DBDE bioremediation (25 mg/kg) using laboratory scale soil slurry microcosms. It was found that effective biodegradation of DBDE occurred in all microcosms. Various biometabolites were identified, namely polybrominated diphenyl ethers congeners and hydroxylated brominated diphenyl ether. Reductive debrominated products such as tri-BDE to hepta-BDE congeners were also detected, and their total concentrations ranged from 77.83 to 91.07 ng/g. The mechanism of DBDE biodegradation in soil slurry microcosms is proposed to consist of a series of biological reactions involving hydroxylation and debromination. Catechol 2,3-oxygenase genes, which are able to bring about meta-cleavage at specific unbrominated locations in carbon backbones, were identified as present during the DBDE biodegradation. No obvious effect on the ecological functional potential based on community-level physiological profiling was observed during DBDE biodegradation, and one major facultative Pseudomonas sp. (99 % similarity) was identified in the various soil slurry microcosms. These findings provide an important basis that should help environmental engineers to design future DBDE bioremediation systems that use a practical microcosm system. A bacterial-mixed culture can be selected as part of the bioaugmentation process for in situ DBDE bioremediation. A soil/water microcosm system can be successfully applied to carry out ex situ DBDE bioremediation.

  8. Ether production with multi-stage reaction of olefins

    SciTech Connect

    Harandi, M.N.

    1993-07-13

    A multistage process is described for etherifying a mixed C[sub 4] + olefinic hydrocarbon feedstock containing diene, isoalkene and nalkene, comprising: contacting the olefinic feedstock and aliphatic alcohol in a first reaction stage reaction zone under etherification conditions with acid etherification catalyst to convert a major amount of the isoalkene to C[sub 5] + tertiary-alkyl ether; recovering a reactant effluent from the first stage containing tertiary-alkyl ether product, unreacted alcohol and unreacted olefin comprising n-alkene and diene; separating an ether-rich C[sub 5] + liquid product stream from the first stage effluent in a first product recovery section; reacting at least a fraction of the first stage effluent unconverted olefins and alcohol fraction under low severity oligomerization conditions comprising moderate temperature between 70 C and 280 C and space velocity of 0.5-50 WHSV based on total olefin in the feed in a secondary stage catalytic reaction zone containing porous solid acid oligomerization catalyst particles to oligomerize a major portion of diene; recovering a C[sub 5]+ liquid product stream from secondary stage effluent; and recovering n-alkene substantially free of diene from secondary stage effluent.

  9. Spiroborate ester-mediated asymmetric synthesis of beta-hydroxy ethers and its conversion to highly enantiopure beta-amino ethers.

    PubMed

    Huang, Kun; Ortiz-Marciales, Margarita; Correa, Wildeliz; Pomales, Edgardo; López, Xaira Y

    2009-06-01

    Borane-mediated reduction of aryl and alkyl ketones with alpha-aryl- and alpha-pyridyloxy groups affords beta-hydroxy ethers in high enantiomeric purity (up to 99% ee) and in good yield, using as catalyst 10 mol % of spiroborate ester 1 derived from (S)-diphenylprolinol. Representative beta-hydroxy ethers are successfully converted to beta-amino ethers, with minor epimerization, by phthalimide substitution under Mitsunobu's conditions followed by hydrazinolysis to obtain primary amino ethers or by imide reduction with borane to afford beta-2,3-dihydro-1H-isoindol ethers. Nonracemic Mexiletine and nAChR analogues with potential biological activity are also synthesized in excellent yield by mesylation of key beta-hydroxy pyridylethers and substitution with five-, six-, and seven-membered ring heterocyclic amines. PMID:19413288

  10. Electro-osmotic drag effect on the methanol permeation for sulfonated poly(ether ether ketone) and nafion 117 membranes.

    PubMed

    Chi, Nguyen Thi Que; Bae, Byungchan; Kim, Dukjoon

    2013-11-01

    Electro-osmotic drag effect on the methanol permeation was investigated for sulfonated poly(ether ether ketone) (sPEEK) membrane, and its result was compared with that of Nafion 117 membrane. The electro-osmotic drag coefficient was determined from the limiting current density measured at different temperature. The methanol permeability of sPEEK membrane increased with temperature but its temperature dependence was not as strong as that of Nafion 117 membrane. The methanol permeability or the total methanol flux of Nafion 117 membrane was at least twice higher than that of sPEEK70 membrane (sPEEK membrane with 70% sulfonation degree), as the methanol permeation was highly contributed by the electro-osmotic drag effect. This higher electro-osmotic drag of Nafion 117 membrane is attributed to the bigger ion cluster and waster channel in nanophase and thus more free water absorption than sPEEK membrane.

  11. An estimation of fatigue life for a carbon fibre/poly ether ether ketone hip joint prosthesis.

    PubMed

    Akay, M; Aslan, N

    1995-01-01

    A fracture mechanics approach was applied to estimate the life of a prosthesis injection moulded from short carbon fibre reinforced poly ether ether ketone. Flexural modulus and strength, fracture toughness, fatigue endurance limit, fatigue crack growth rate and threshold stress intensity factor were determined. The dimensions of the test pieces were selected to yield fibre orientation and fibre length distributions similar to those obtained in the prosthesis. Stress levels generated in the prosthesis under different activities were estimated by conducting three-dimensional finite element analysis. It was shown by a fracture mechanics approach that a fatigue failure due to the propagation of an embedded elliptical slit, under these stresses, would be unlikely for a crack length smaller than 1.85 mm. However, the cement would fail under the same conditions, irrespective of the type of the prosthesis employed.

  12. Intermolecular ionic cross-linked sulfonated poly(ether ether ketone) membranes containing diazafluorene for direct methanol fuel cell applications

    NASA Astrophysics Data System (ADS)

    Liang, Yu; Gong, Chenliang; Qi, Zhigang; Li, Hui; Wu, Zhongying; Zhang, Yakui; Zhang, Shujiang; Li, Yanfeng

    2015-06-01

    A series of novel ionic cross-linking sulfonated poly(ether ether ketone) (SPEEK) membranes containing the diazafluorene functional group are synthesized to reduce the swelling ratio and methanol permeability for direct methanol fuel cell (DMFC) applications. The ionic cross-linking is realized by the interaction between sulfonic acid groups and pyridyl in diazafluorene. The prepared membranes exhibit good mechanical properties, adequate thermal stability, good oxidative stability, appropriate water uptake and low swelling ratio. Moreover, the ionic cross-linked membranes exhibit lower methanol permeability in the range between 0.56 × 10-7 cm2 s-1 and 1.8 × 10-7 cm2 s-1, which is lower than Nafion 117, and they exhibit higher selectivity than Nafion 117 at 30 °C on the basis of applicable proton conductivity.

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

    PubMed

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha

    2014-03-25

    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.

  14. Pressure and temperature dependence of excess enthalpies of methanol + tetraethylene glycol dimethyl ether and methanol + polyethylene glycol dimethyl ether 250

    SciTech Connect

    Lopez, E.R.; Coxam, J.Y.; Fernandez, J.; Grolier, J.P.E.

    1999-12-01

    The excess molar enthalpies at 323.15 K, 373.15 K, and 423.15 K, at 8 MPa, are reported for the binary mixtures methanol + tetraethylene glycol dimethyl ether (TEGDME) and methanol + poly(ethylene glycol) dimethyl ether 250 (PEGDME 250). Excess molar enthalpies were determined with a Setaram C-80 calorimeter equipped with a flow mixing cell. For both systems, the excess enthalpies are positive over the whole composition range, increasing with temperature. The H{sup E}(x) curves are slightly asymmetrical, and their maxima are skewed toward the methanol-rich region. The excess enthalpies slightly change with the pressure, the sign of this change being composition-dependent. In the case of mixtures with TEGDME, the experimental H{sup E} values have been compared with those predicted with the Gmehling et al. version of UNIFAC (Dortmund) and the Nitta-Chao and DISQUAC group contribution models.

  15. Biosorption and degradation of decabromodiphenyl ether by Brevibacillus brevis and the influence of decabromodiphenyl ether on cellular metabolic responses.

    PubMed

    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

  16. Biosorption and degradation of decabromodiphenyl ether by Brevibacillus brevis and the influence of decabromodiphenyl ether on cellular metabolic responses.

    PubMed

    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.

  17. Size-exclusion chromatography of ultrahigh molecular weight methylcellulose ethers and hydroxypropyl methylcellulose ethers for reliable molecular weight distribution characterization.

    PubMed

    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

  18. Size-exclusion chromatography of ultrahigh molecular weight methylcellulose ethers and hydroxypropyl methylcellulose ethers for reliable molecular weight distribution characterization.

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-11-01

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

  20. Safety Assessment of Alkyl PEG/PPG Ethers as Used in Cosmetics.

    PubMed

    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.

  1. Safety Assessment of Alkyl PEG/PPG Ethers as Used in Cosmetics.

    PubMed

    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

  2. Effect of temperature and pressure on the volumetric properties of branched and cyclic ethers

    SciTech Connect

    Govender, U.P.; Letcher, T.M.; Garg, S.K.; Ahluwalia, J.C.

    1996-01-01

    The densities of liquid diisopropyl ether, 1,1-dimethylethyl methyl ether, 1,1-dimethylpropyl methyl ether, tetrahydrofuran, tetrahydropyran, and 1,4-dioxane have been determined from 288.15 to 328.15 K at pressures ranging from 0.1 to 8 MPa. The molar volumes (derived from densities) have been fitted to a polynomial as a function of temperature and pressure. Where available, the results have been compared to literature values.

  3. Visible-Light-Promoted Oxidative [4 + 2] Cycloadditions of Aryl Silyl Enol Ethers.

    PubMed

    Yang, Bo; Lu, Zhan

    2016-08-19

    Visible-light-promoted oxidative [4 + 2] cycloadditions of ε,3-unsaturated silyl enol ethers have been developed to efficiently and diastereoselectively construct polycyclic skeletons under mild conditions. The diastereoselectivities were dependent on the stereoconfiguration of silyl enol ether, substitutions on the link, as well as electric properties of substitutions on aryl rings. The intermediates could be trapped by TEMPO, oxygen or methanol. Mechanistic studies indicated the reaction was initiated by one-electron oxidation of the silyl enol ether. PMID:27391768

  4. Evaluation of alternariol and alternariol methyl ether for mutagenic activity in Salmonella typhimurium

    SciTech Connect

    Davis, V.M.; Stack, M.E. )

    1994-10-01

    Alternariol and alternariol methyl ether were tested in the Ames Salmonella typhimurium assay, and both were shown, with and without metabolic activation, to be nonmutagenic to strains TA98 and TA100. The finding of other investigators that alternariol methyl ether is weakly mutagenic to Ta98 without metabolic activation could have resulted from the presence of a small amount of one of the highly mutagenic altertoxins in the alternariol methyl ether originally tested. 9 refs., 3 figs., 1 tab.

  5. Fluctuating asymmetry and condition in golden shiner (Notemigonus crysoleucas) and channel catfish (Ictalurus punctatus) reared in sublethal concentrations of isopropyl methylphosphonic acid.

    PubMed

    Green, Chris C; Lochmann, Steve E

    2006-01-01

    Fluctuating asymmetry (FA; small, random differences between the left and right sides of a bilateral character) has been related to embryological stress during development. Some populations exhibit positive relations between FA and exposure to toxicants during development. The United States has agreed to demilitarize chemical warfare agents in accordance with the Chemical Weapons Convention Treaty. Isopropyl methylphosphonic acid (IMPA), the main hydrolysis product of sarin, could be introduced accidentally into the environment during demilitarization. The present study examined the use of FA as a biomarker of developmental stress caused by sublethal exposures to IMPA. A suite of morphometric and meristic traits were measured in two fish species exposed to IMPA. Significant differences were found in composite FA among groups of channel catfish (Ictalurus punctatus) exposed to sublethal concentrations of IMPA during development. No differences were found in composite FA among groups of golden shiner (Notemigonus crysoleucas) exposed to IMPA. No relation was found between individual relative condition and FA in channel catfish or golden shiner.

  6. To prepare and characterize microcrystalline cellulose granules using water and isopropyl alcohol as granulating agents and determine its end-point by thermal and rheological tools.

    PubMed

    Chaudhari, Smruti P; Dave, Rutesh H

    2015-05-01

    Microcrystalline cellulose (MCC-102) is one of the most commonly used excipient in the pharmaceutical industry. For this research purpose, authors have developed a different technique to determine the end point for MCC-102 using water and isopropyl alcohol 70% (IPA) as granulating agent. Wet and dry granules obtained were characterized for their flow properties using the powder rheometer and thermal analysis. Powder rheometer was used to measure basic flowability energy (BFE), specific energy (SE), percentage compressibility, permeability and aeration. Thermal analysis includes effusivity and differential scanning calorimetry (DSC) measurements. BFE and SE results showed water granules requires high energy as compared to IPA granules. Permeability and compressibility results suggest IPA forms more porous granules and have better compressibility as compared to water granules. Hardness data reveals interesting phenomena in which as the amount of water increases, hardness decreases and vice-versa for IPA. Optimal granules were obtained in the range of 45-55% w/w. DSC data supported the formation of optimal granules. Empirical measurements like angle of repose did not reveal any significant differences between powder flow among various granules. In this paper, with the help of thermal effusivity and powder rheology we were able to differentiate between various powder flows and determine the optimal range for granule formation.

  7. Normoxic polymer gel dosimetry using less toxic monomer of N-isopropyl acrylamide and X-ray computed tomography for radiation therapy applications

    PubMed Central

    Ghavami, Seyed-Mostafa; Mesbahi, Asghar; Pesianian, Ismaeel; Shafaee, Abbas; Aliparasti, Mohammad-Reza

    2010-01-01

    Background Polymer gel dosimetry has been used extensively in radiation therapy for its capability in depicting a three dimensional view of absorbed dose distribution. However, more studies are required to find less toxic and more efficient polymers for application in radiotherapy dosimetry. Aim The purpose of this work was to evaluate the N-isopropyl acrylamide (NIPAM) gel dosimetric characteristics and optimize the protocol for X-ray computed tomography (CT) imaging of gel dosimeters for radiation therapy application. Material and methods A polymer gel dosimeter based on NIPAM monomer was prepared and irradiated with 60Co photons. The CT number changes following irradiation were extracted from CT images obtained with different sets of imaging parameters. Results The results showed the dose sensitivity of ΔNCT (H) = 0.282 ± 0.018 (H Gy−1) for NIPAM gel dosimeter. The optimized set of imaging exposure parameters was 120 kVp and 200 mA with the 10 mm slice thickness. Results of the depth dose measurement with gel dosimeter showed a great discrepancy with the actual depth dose data. Conclusion According to the current study, NIPAM-based gel dosimetry with X-ray CT imaging needs more technical development and formulation refinement to be used for radiation therapy application. PMID:24376945

  8. N-isopropyl(I-123)p-lodoamphetamine brain scans with single-photon emission tomography discordance with transmission computed tomography

    SciTech Connect

    Lee, R.G.; Hill, T.C.; Holman, B.L.; Clouse, M.E.

    1982-12-01

    Transmission computed tomography (CT) brain scans were compared with N-isopropyl (I-123)p-iodoamphetamine (IMP) single-photon emission computed tomography (SPECT) brain scans to determine if there was a correlation between morphology, as seen on CT, and cerebral perfusion changes detected by IMP SPECT. In 12 patients with acute stroke, four showed no discordance between the edema seen on CT and perfusion deficits seen on IMP SPECT; five had positive IMP scans while initial CT scans were negative and follow-up CT scans demonstrated edema in the region of perfusion deficit seen on the IMP scans; and in four patients, the average perfusion deficit was 2.3 times greater than the edema shown on CT at 2 cm above the canthalmeatal line. In nine control patients, there was a 2.3% difference in IMP activity between the right and left hemispheres. The 12 stroke patients showed 30.3% less IMP activity in the abnormal hemisphere compared with the normal side. Three patients, one with temporal lobe seizure, one with hemiballismus, and the third with idiopathic intention tumor, had 54% greater IMP activity on the side of movement or seizure than on the normal side. The discordance between IMP and CT scans was clearly demonstrated in cases in which CT showed no abnormality but IMP provided information on function, reflected in increased or decreased cerebral perfusion.

  9. Water absorbing and antibacterial properties of N-isopropyl acrylamide grafted and collagen/chitosan immobilized polypropylene nonwoven fabric and its application on wound healing enhancement.

    PubMed

    Wang, Chyung-Chyung; Su, Ching-Hua; Chen, Cheng-Chi

    2008-03-15

    A durable sandwich wound dressing system with high liquid absorbing, biocompatibility, and antibacterial properties was designed. Various solution weight ratios of collagen to chitosan were used to immobilize on the polypropylene nonwoven fabric, which were pregrafted with acrylic acid (AA) or N-isopropyl acrylamide (NIPAAm) to construct a durable sandwich wound dressing membrane with high water absorbing, easy removal, and antibacterial activity. Swelling properties and antibacterial activity of the membranes were measured, and wound healing enhancement by skin full-thickness excision on animal model was examined. The results indicated that NIPAAm-grafted and collagen/chitosan-immobilized polypropylene nonwoven fabric (PP-NIPAAm-collagen-chitosan) showed a better healing effect than AA-grafted and collagen/chitosan-immobilized polypropylene nonwoven fabric (PP-AA-collagen-chitosan). The wound treated with PP-NIPAAm-collagen-chitosan demonstrated the excellent remodeling effect in histological examination with respect to the construction of vein, epidermis, and dermis at 21 days after skin injury. The values of water uptake and water diffusion coefficient for PP-NIPAAm-collagen-chitosan were higher than that for PP-AA-collagen-chitosan under a given solution weight ratio of collagen/chitosan. Both PP-NIPAAm-collagen-chitosan and PP-AA-collagen-chitosan demonstrated antibacterial activity.

  10. Molecular and crystal structures of 4'-hydroxy derivative of (3R,6R)-3-methyl-6-isopropyl-2-(4-phenylbenzylidene)cyclohexanone

    SciTech Connect

    Kutulya, L. A.; Kulishov, V. I.; Shishkina, S. V.; Tolochko, A. S.; Roshal', A. D.; Shishkin, O. V.

    2008-05-15

    The molecular and crystal structures of the 4-hydroxy derivative of (3R,6R)-3-methyl-6-isopropyl-2-(4-phenylbenzylidene)cyclohexanone are determined by X-ray diffraction analysis. Single crystals are orthorhombic, a = 9.147(2) A, b = 12.959(2) A, c = 15.695(5) A, V = 1860.4(7) A{sup 3}, Z = 4, and space group P2{sub 1}2{sub 1}2{sub 1}. The cyclohexanone ring in the crystal structure has an asymmetric chair conformation. The puckering parameters are as follows: the puckering amplitude S is 0.91, and the puckering angles {theta} and {psi} are equal to 20.2{sup o} and 10.4{sup o}, respectively. It is established that the enone fragment and the cyclohexanone ring in molecules are flattened considerably. In the crystal structure, the molecules are linked by the hydrogen bonds (bond length, 1.85 A). The structural features and the strength of the hydrogen bonds for the compound under investigation and its analogue with one benzene ring are compared using the X-ray diffraction and IR spectroscopic data.

  11. Synthesis and optimization of fluorescent poly(N-isopropyl acrylamide)-coated surfaces by atom transfer radical polymerization for cell culture and detachment

    PubMed Central

    Cooperstein, Marta A.; Bluestein, Blake M.; Canavan, Heather E.

    2014-01-01

    Although there are many stimulus-responsive polymers, poly(N-isopropyl acrylamide) (pNIPAM) is of special interest due to the phase change it undergoes in a physiologically relevant temperature range that leads to the release of cells and proteins. The nondestructive release of cells opens up a wide range of applications, including the use of pNIPAM for cell sheet and tissue engineering. In this work, pNIPAM surfaces were generated that can be distinguished from the extracellular matrix. A polymerization technique was adapted that was previously used by Mendez, and the existing protocol was optimized for the culture of mammalian cells. The resulting surfaces were characterized with X-ray photoelectron spectroscopy and goniometry. The developed pNIPAM surfaces were further adapted by incorporation of 5-acrylamidofluorescein to generate fluorescent pNIPAM-coated surfaces. Both types of surfaces (fluorescent and nonfluorescent) sustained cellular attachment and produced cellular detachment of ∼90%, and are therefore suitable for the generation of cell sheets for engineered tissues and other purposes. These surfaces will be useful tools for experiments investigating cellular detachment from pNIPAM and the pNIPAM/cell interface. PMID:25708629

  12. Comparison of N-isopropyl (/sup 123/I) p-iodoamphetamine brain scans using Anger camera scintigraphy and single-photon emission tomography

    SciTech Connect

    Lee, R.G.; Hill, T.C.; Holman, B.L.; Uren, R.; Clouse, M.E.

    1982-12-01

    N-isopropyl (/sup 123/I) p-iodoamphetamine (IMP), which is extracted by the brain in proportion to regional blood flow, has been shown to be useful with single-photon emission tomography (SPECT) in the assessment of pathologic states related to blood flow. Because emission tomographic equipment is not yet available at most hospitals, the authors compared IMP brain images obtained with an Anger camera with those obtained by SPECT to determine the usefulness of IMP scintigraphy. Thirty-nine pairs of studies were performed on 12 control patients, 14 patients with stroke, three patients with tumors, and a miscellaneous group of eight patients. Planar scintigraphy showed good correlation with SPECT in determining the presence or absence of abnormality in all patients except one with a very small brain stem infarction that was not detected by planar imaging. Anger images showed poor contrast resolution compared with SPECT images. It is thus expected that SPECT will result in better lesion detection when smaller lesions are studied. Planar scintigraphy is not capable of providing quantitative measurement of regional cerebral blood flow.

  13. Comparison of N-isopropyl (I-123) p-iodoamphetamine brain scans using Anger camera scintigraphy and single-photon emission tomography

    SciTech Connect

    Lee, R.G.; Hill, T.C.; Holman, B.L.; Uren, R.; Clouse, M.E.

    1982-12-01

    N-isopropyl (I-123) p-iodoamphetamine (IMP), which is extracted by the brain in proportion to regional blood flow, has been shown to be useful with single-photon emission tomography (SPECT) in the assessment of pathologic states related to blood flow. Because emission tomographic equipment is not yet available at most hospitals, the authors compared IMP brain images obtained with an Anger camera with those obtained by SPECT to determine the usefulness of IMP scintigraphy. Thirty-nine pairs of studies were performed on 12 control patients, 14 patients with stroke, three patients with tumors, and a miscellaneous group of eight patients. Planar scintigraphy showed good correlation with SPECT in determining the presence or absence of abnormality in all patients except one with a very small brain stem infarction that was not detected by planar imaging. Anger images showed poor contrast resolution compared with SPECT images. It is thus expected that SPECT will result in better lesion detection when smaller lesions are studied. Planar scintigraphy is not capable of providing quantitative measurement of regional cerebral blood flow.

  14. Stimuli-responsive poly(N-isopropyl acrylamide)-co-tyrosine@gadolinium: Iron oxide nanoparticle-based nanotheranostic for cancer diagnosis and treatment.

    PubMed

    Roy, Ekta; Patra, Santanu; Madhuri, Rashmi; Sharma, Prashant K

    2016-06-01

    In this paper, we have prepared a stimuli-responsive polymer modified gadolinium doped iron oxide nanoparticle (poly@Gd-MNPs) as cancer theranostic agent. The responsive polymer is composed of the poly(N-isopropyl acrylamide)-co-tyrosine unit, which shows excellent loading for the anti-cancer drug (methotrexate) and stimuli dependent release (change in pH and temperature). The in vitro experiment revealed that the poly@Gd-MNPs exhibited T1-weighted MRI capability (r1=11.314mM(-1)s(-1)) with good in-vitro hyperthermia response. The prepared poly@Gd-MNPs has generated quick heating (45°C in 2min) upon exposure to an alternating magnetic field and able to travel a distance of 35cm in 1min in the presence of an external magnet. The poly@Gd-MNPs shows 86% of drug loading capacity with 70% drug release in first 2h. The cytotoxic assay (MTT) demonstrated that the nanoparticle did not affect the viability of normal human fibroblast and efficiently kill the MCF7 cancer cells in the presence of an external magnetic field. To explore the uptake of poly@Gd-MNPs in the cells, bright field cell imaging study was also performed. This study provides a valuable approach for the design of highly sensitive polymer modified gadolinium doped iron oxide-based T1 contrast agents for cancer theranostics. PMID:26962761

  15. Removal of isopropyl alcohol and methanol in ultrapure water production system using a 185 nm ultraviolet and ion exchange system.

    PubMed

    Choi, Jeongyun; Kim, Jong-Oh; Chung, Jinwook

    2016-08-01

    The oxidation of low-molecular-weight (LMW) compounds, including isopropyl alcohol (IPA) and methanol in ultrapure water (UPW) production system was evaluated using the continuously operating 185 nm total organic carbon (TOC) reduction UV and ion exchange system. The initial concentration of compounds was in the range of tens of ppb which was the general feed condition of UV system located after 2 pass reverse osmosis (RO) in the UPW production system. UV irradiation transformed the compounds to less oxidative products that were ultimately converted to CO2. The ion exchange system then removed carboxyl-containing organic acids generated by UV oxidation. It means that the oxidation efficiency of organic compounds by UV irradiation can be accurately measured by the summation of the final product (CO2) and the by-product containing carboxyl functional group. The removal efficiency of LMW compounds decreased when either the initial TOC concentration increased or the UV intensity was reduced. Finally, the insertion of a baffle into the UV oxidation system was found to enhance solution turbulence and improve the oxidation efficiency. PMID:27183336

  16. The multifunctional isopropyl alcohol dehydrogenase of Phytomonas sp. could be the result of a horizontal gene transfer from a bacterium to the trypanosomatid lineage.

    PubMed

    Molinas, Sara M; Altabe, Silvia G; Opperdoes, Fred R; Rider, Mark H; Michels, Paul A M; Uttaro, Antonio D

    2003-09-19

    Isopropyl alcohol dehydrogenase (iPDH) is a dimeric mitochondrial alcohol dehydrogenase (ADH), so far detected within the Trypanosomatidae only in the genus Phytomonas. The cloning, sequencing, and heterologous expression of the two gene alleles of the enzyme revealed that it is a zinc-dependent medium-chain ADH. Both polypeptides have 361 amino acids. A mitochondrial targeting sequence was identified. The mature proteins each have 348 amino acids and a calculated molecular mass of 37 kDa. They differ only in one amino acid, which can explain the three isoenzymes and their respective isoelectric points previously found. A phylogenetic analysis locates iPDH within a cluster with fermentative ADHs from bacteria, sharing 74% similarity and 60% identity with Ralstonia eutropha ADH. The characterization of the two bacterially expressed Phytomonas enzymes and the comparison of their kinetic properties with those of the wild-type iPDH and of the R. eutropha ADH strongly support the idea of a horizontal gene transfer event from a bacterium to a trypanosomatid to explain the origin of the iPDH in Phytomonas. Phytomonas iPDH and R. eutropha ADH are able to use a wide range of substrates with similar Km values such as primary and secondary alcohols, diols, and aldehydes, as well as ketones such as acetone, diacetyl, and acetoin. We speculate that, as for R. eutropha ADH, Phytomonas iPDH acts as a safety valve for the release of excess reducing power. PMID:12853449

  17. Design, synthesis, and biological activity of oxime ether strobilurin derivatives containing indole moiety as novel fungicide.

    PubMed

    Xie, Ya-Qiang; Huang, Zi-Long; Yan, Hui-Dong; Li, Jun; Ye, Li-Yi; Che, Li-Ming; Tu, Song

    2015-06-01

    Twenty-one novel oxime ether strobilurins containing indole moiety, which employed an indole group to stabilize the E-styryl group in Enoxastrobin, were designed and synthesized. The biological assay indicated that most compounds exhibited potent fungicidal activities. The structure-activity relationship study demonstrated that the synthesized methyl 3-methoxypropenoate oxime ethers 7b-e exhibited remarkably high activities among all the synthesized oxime ether compounds 7. Moreover, the fungicidal activities of methyl α-(methoxyimino)benzeneacetate oxime ethers compounds 7f-i and N-methoxy-carbamic acid methyl esters compounds 7j-m showed significant differences compared to the corresponding products of ammonolysis. PMID:25346294

  18. Structures and Biosynthesis of Corvol Ethers--Sesquiterpenes from the Actinomycete Kitasatospora setae.

    PubMed

    Rabe, Patrick; Pahirulzaman, Khomaizon A K; Dickschat, Jeroen S

    2015-05-11

    Here we present the functional characterization of a sesquiterpene cyclase from Kitasatospora setae. The enzyme converts the sesquiterpene precursor farnesyl diphosphate (FPP) into two previously unknown and unstable sesquiterpene ethers for which we propose the trivial names corvol ethers A and B. Both compounds were purified and their structures were determined by one- and two-dimensional NMR spectroscopy. A biosynthetic mechanism for the FPP cyclization by the corvol ether synthase was proposed. The results from the incubation experiments of the corvol ether synthase with isotopically labeled precursors were in line with this mechanism, while alternative mechanisms could clearly be ruled out. PMID:25809275

  19. Polybrominated diphenyl ethers (PBDEs): new pollutants-old diseases.

    PubMed

    Siddiqi, Muhammad Akmal; Laessig, Ronald H; Reed, Kurt D

    2003-10-01

    Polybrominated diphenyl ethers (PBDEs) are a class of recalcitrant and bioaccumulative halogenated compounds that have emerged as a major environmental pollutant. PBDEs are used as a flame-retardant and are found in consumer goods such as electrical equipment, construction materials, coatings, textiles and polyurethane foam (furniture padding). Similar in structure to polychlorinated biphenyls (PCBs), PBDEs resist degradation in the environment. Less brominated PBDEs like tetra-, penta- and hexa- demonstrate high affinity for lipids and can accumulate in the bodies of animals and humans. Breast milk from North American women contained much higher amounts of PBDEs than levels in breast milk from Swedish women, indicating that North American exposures to PBDEs may be particularly high. Evidence to date suggests that tetra- and penta-BDEs are likely to be the more toxic and bioaccumulative of the PBDE compounds, compared to octa- and deca-congeners. PBDEs are sold as mixtures, under names such as "pentabromodiphenyl ether" and "octabromodiphenyl ether." The pentabromo product is a mixture of tetra-BDEs and penta-BDEs in approximately equal amounts. Pentabromo consists of PBDEs that are believed to be the most toxic. This mixture has been banned by the European Union, but is still used in North America. The United States is the leading producer and user of pentabromo. In August 2003, the State of California passed a bill to phase out the use of penta- and octa-PBDE by 2008. The toxicology of PBDEs is not well understood, but PBDEs have been associated with tumors, neurodevelopmental toxicity and thyroid hormone imbalance. The neurotoxic effects of PBDEs are similar to those observed for PCBs. Children exposed to PBDEs are prone to subtle but measurable developmental problems. It is presumed that PBDEs are endocrine disruptors, but research in this area is scant. Further studies are imperative in a multitude of health and environmental disciplines to determine the

  20. Polybrominated diphenyl ethers (PBDEs): new pollutants-old diseases.

    PubMed

    Siddiqi, Muhammad Akmal; Laessig, Ronald H; Reed, Kurt D

    2003-10-01

    Polybrominated diphenyl ethers (PBDEs) are a class of recalcitrant and bioaccumulative halogenated compounds that have emerged as a major environmental pollutant. PBDEs are used as a flame-retardant and are found in consumer goods such as electrical equipment, construction materials, coatings, textiles and polyurethane foam (furniture padding). Similar in structure to polychlorinated biphenyls (PCBs), PBDEs resist degradation in the environment. Less brominated PBDEs like tetra-, penta- and hexa- demonstrate high affinity for lipids and can accumulate in the bodies of animals and humans. Breast milk from North American women contained much higher amounts of PBDEs than levels in breast milk from Swedish women, indicating that North American exposures to PBDEs may be particularly high. Evidence to date suggests that tetra- and penta-BDEs are likely to be the more toxic and bioaccumulative of the PBDE compounds, compared to octa- and deca-congeners. PBDEs are sold as mixtures, under names such as "pentabromodiphenyl ether" and "octabromodiphenyl ether." The pentabromo product is a mixture of tetra-BDEs and penta-BDEs in approximately equal amounts. Pentabromo consists of PBDEs that are believed to be the most toxic. This mixture has been banned by the European Union, but is still used in North America. The United States is the leading producer and user of pentabromo. In August 2003, the State of California passed a bill to phase out the use of penta- and octa-PBDE by 2008. The toxicology of PBDEs is not well understood, but PBDEs have been associated with tumors, neurodevelopmental toxicity and thyroid hormone imbalance. The neurotoxic effects of PBDEs are similar to those observed for PCBs. Children exposed to PBDEs are prone to subtle but measurable developmental problems. It is presumed that PBDEs are endocrine disruptors, but research in this area is scant. Further studies are imperative in a multitude of health and environmental disciplines to determine the

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Catalytic Dealkylation of Ethers to Alcohols on Metal Surfaces.

    PubMed

    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

  3. An aging study of wire chambers with dimethyl ether

    SciTech Connect

    Jibaly, M.; Chrusch, P. Jr.; Hilgenberg, G.; Majewski, S.; Wojcik, R.; Sauli, F.; Gaudaen, J.

    1989-02-01

    The authors report results on the aging of different types of resistive and non-resistive wires in wire chambers filled with dimethyl ether (DME) of varying degrees of purity. Among the Freon impurities detected in our DME batches, only Freon-11 was found to contribute to the aging process. Of the resistive wires, Nicotin and Stablohm produced fast aging, whereas stainless steel withstood extended irradiation in purified DME (up to 1 C/cm) without any apparent damage. Gold-plated tungsten and molybdenum wires produced results comparable to those of the stainless steel.

  4. Ether-based nonflammable electrolyte for room temperature sodium battery

    NASA Astrophysics Data System (ADS)

    Feng, Jinkui; Zhang, Zhen; Li, Lifei; Yang, Jian; Xiong, Shenglin; Qian, Yitai

    2015-06-01

    Safety problem is one of the key points that hinder the development of room temperature sodium batteries. In this paper, four well-known nonflammable organic compounds, Trimethyl Phosphate (TMP), Tri(2,2,2-trifluoroethyl) phosphite (TFEP), Dimethyl Methylphosphonate (DMMP), Methyl nonafluorobuyl Ether (MFE), are investigated as nonflammable solvents in sodium batteries for the first time. Among them, MFE is stable towards sodium metal at room temperature. The electrochemical properties and electrode compatibility of MFE based electrolyte are investigated. Both Prussian blue cathode and carbon nanotube anode show good electrochemical performance retention in this electrolyte. The results suggest that MFE is a promising option as nonflammable electrolyte additive for sodium batteries.

  5. Dimethyl ether production from methanol and/or syngas

    SciTech Connect

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

    2015-02-17

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

  6. Chemistry and properties of new poly(arylene ether imidazoles)

    NASA Technical Reports Server (NTRS)

    Connell, J. W.; Hergenrother, P. M.

    1990-01-01

    As part of a program to develop high-temperature high-performance structural resins for aerospace applications, the chemistry and properties of new poly(arylene ether imidazoles) were investigated. The polymers were prepared by the nucleophilic displacement reaction of aromatic bis(imidazolephenols) with activated aromatic difluoro compounds. The amorphous thermoplastic polymers exhibited glass transition temperatures from 230 to 301 C, inherent viscosities from 0.46 to 1.46 dL/g, and number-average molecular weights as high as 59,300 g/mole. The polymers exhibit good toughness, adhesive, composite, and film properties. The chemical, physical, and mechanical properties of these materials are discussed.

  7. Experimental and Theoretical Studies on Corvol Ether Biosynthesis.

    PubMed

    Rabe, Patrick; Janusko, Aron; Goldfuss, Bernd; Dickschat, Jeroen S

    2016-01-01

    The biosynthesis of corvol ethers A and B, two sesquiterpenes from Kitasatospora setae, proceeds with involvement of either one 1,3- or two sequential 1,2-hydride shifts. Quantum chemical calculations revealed that the sequence of two 1,2-hydride shifts is energetically favoured. Labelling experiments were in agreement with this finding. In addition, the stereochemical course of a reprotonation step was investigated by incubation of (13)C-labelled isotopomers of farnesyl diphosphate in water and in deuterium oxide. PMID:26635093

  8. Crown ether derivative assisted growth of oriented polyaniline nanotubes

    NASA Astrophysics Data System (ADS)

    Xia, Haibing; Cheng, Daming; Lam, Peisuan; Chan, Hardy Sze On

    2006-08-01

    We report a chemical route to synthesize oriented arrays of conducting polyaniline (PANI) nanotubes (60-150 nm in diameter and a few micrometres in length) by hydrogen-bonding directionality in the presence of a crown ether derivative (CE-SO3K) and ammonium persulfate (APS) in HCl solution. The morphology of the oriented PANI nanotubes was confirmed by SEM and TEM images. The effects of reaction conditions on the morphology of the resultant PANI nanostructures were studied. The chemical and electronic structures of the PANI nanotubes were also studied by FTIR and UV-vis spectrometry, respectively.

  9. Polybrominated Diphenyl Ethers: Structure Determination and Trends in Antibacterial Activity.

    PubMed

    Liu, Hongbing; Lohith, Katheryn; Rosario, Margaret; Pulliam, Thomas H; O'Connor, Robert D; Bell, Lori J; Bewley, Carole A

    2016-07-22

    Antibacterial-guided fractionation of the Dictyoceratid sponges Lamellodysidea sp. and two samples of Dysidea granulosa yielded 14 polybrominated, diphenyl ethers including one new methoxy-containing compound (8). Their structures were elucidated by interpretation of spectroscopic data of the natural product and their methoxy derivatives. Most of the compounds showed strong antimicrobial activity with low- to sub-microgram mL(-1) minimum inhibitory concentrations against drug-susceptible and drug-resistant strains of Staphylococcus aureus and Enterococcus faecium, and two compounds inhibited Escherichia coli in a structure-dependent manner. PMID:27399938

  10. Structure and Reactivity of Alkyl Ethers Adsorbed on CeO(2)(111) Model Catalysts

    SciTech Connect

    Calaza, Florencia C; Chen, Tsung-Liang; Mullins, David R; Overbury, Steven {Steve} H

    2011-01-01

    The effect of surface hydroxyls on the adsorption of ether on ceria was explored. Adsorption of dimethyl ether (DME) and diethyl ether (DEE) on oxidized and reduced CeO{sub 2}(111) films was studied and compared with Ru(0001) using RAIRS and sXPS within a UHV environment. On Ru(0001) the ethers adsorb weakly with the molecular plane close to parallel to the surface plane. On the ceria films, the adsorption of the ethers was stronger than on the metal surface, presumably due to stronger interaction of the ether oxygen lone pair electrons with a cerium cation. This interaction causes the ethers to tilt away from the surface plane compared to the Ru(0001) surface. No pronounced differences were found between oxidized (CeO{sub 2}) and reduced (CeOx) films. The adsorption of the ethers was found to be perturbed by the presence of OH groups on hydroxylated CeOx. In the case of DEE, the geometry of adsorption resembles that found on Ru, and in the case of dimethyl ether DME is in between that one found on clean CeOx and the metal surface. Decomposition of the DEE was observed on the OH/CeOx surface following high DEE exposure at 300 K and higher temperatures. Ethoxides and acetates were identified as adsorbed species on the surface by means of RAIRS and ethoxides and formates by s-XPS. No decomposition of dimethyl ether was observed on the OH/CeOx at these higher temperatures, implying that the dissociation of the C-O bond from ethers requires the presence of {beta}-hydrogen.

  11. Structure and Reactivity of Alkyl Ethers Adsorbed on CeO2(111) Model Catalysts

    SciTech Connect

    F Calaza; T Chen; D Mullins; S Overbury

    2011-12-31

    The effect of surface hydroxyls on the adsorption of ether on ceria was explored. Adsorption of dimethyl ether (DME) and diethyl ether (DEE) on oxidized and reduced CeO{sub 2}(111) films was studied and compared with Ru(0001) using RAIRS and sXPS within a UHV environment. On Ru(0001) the ethers adsorb weakly with the molecular plane close to parallel to the surface plane. On the ceria films, the adsorption of the ethers was stronger than on the metal surface, presumably due to stronger interaction of the ether oxygen lone pair electrons with a cerium cation. This interaction causes the ethers to tilt away from the surface plane compared to the Ru(0001) surface. No pronounced differences were found between oxidized (CeO{sub 2}) and reduced (CeOx) films. The adsorption of the ethers was found to be perturbed by the presence of OH groups on hydroxylated CeOx. In the case of DEE, the geometry of adsorption resembles that found on Ru, and in the case of dimethyl ether DME is in between that one found on clean CeOx and the metal surface. Decomposition of the DEE was observed on the OH/CeOx surface following high DEE exposure at 300 K and higher temperatures. Ethoxides and acetates were identified as adsorbed species on the surface by means of RAIRS and ethoxides and formates by s-XPS. No decomposition of dimethyl ether was observed on the OH/CeOx at these higher temperatures, implying that the dissociation of the C-O bond from ethers requires the presence of {beta}-hydrogen.

  12. Metabolism of Diethyl Ether and Cometabolism of Methyl tert-Butyl Ether by a Filamentous Fungus, a Graphium sp

    PubMed Central

    Hardison, L. K.; Curry, S. S.; Ciuffetti, L. M.; Hyman, M. R.

    1997-01-01

    In this study, evidence for two novel metabolic processes catalyzed by a filamentous fungus, Graphium sp. strain ATCC 58400, is presented. First, our results indicate that this Graphium sp. can utilize the widely used solvent diethyl ether (DEE) as the sole source of carbon and energy for growth. The kinetics of biomass accumulation and DEE consumption closely followed each other, and the molar growth yield on DEE was indistinguishable from that with n-butane. n-Butane-grown mycelia also immediately oxidized DEE without the extracellular accumulation of organic oxidation products. This suggests a common pathway for the oxidation of both compounds. Acetylene, ethylene, and other unsaturated gaseous hydrocarbons completely inhibited the growth of this Graphium sp. on DEE and DEE oxidation by n-butane-grown mycelia. Second, our results indicate that gaseous n-alkane-grown Graphium mycelia can cometabolically degrade the gasoline oxygenate methyl tert-butyl ether (MTBE). The degradation of MTBE was also completely inhibited by acetylene, ethylene, and other unsaturated hydrocarbons and was strongly influenced by n-butane. Two products of MTBE degradation, tert-butyl formate (TBF) and tert-butyl alcohol (TBA), were detected. The kinetics of product formation suggest that TBF production temporally precedes TBA accumulation and that TBF is hydrolyzed both biotically and abiotically to yield TBA. Extracellular accumulation of TBA accounted for only a maximum of 25% of the total MTBE consumed. Our results suggest that both DEE oxidation and MTBE oxidation are initiated by cytochrome P-450-catalyzed reactions which lead to scission of the ether bonds in these compounds. Our findings also suggest a potential role for gaseous n-alkane-oxidizing fungi in the remediation of MTBE contamination. PMID:16535667

  13. Carbon isotopic fractionation during anaerobic biotransformation of methyl tert-butyl ether and tert-amyl methyl ether.

    PubMed

    Somsamak, Piyapawn; Richnow, Hans H; Häggblom, Max M

    2005-01-01

    The fuel oxygenate methyl tert-butyl ether (MTBE) has been frequently detected in groundwater and surface water. Since contaminated sites are often subsurface, anaerobic degradation of MTBE will likely be significant for remediation. As traditional approaches to evaluate biodegradation generally involve laboratory microcosm studies which require time and resources, innovative approaches are needed to demonstrate active in situ biodegradation of MTBE. This study was conducted to gather information at the laboratory level to evaluate the potential of applying carbon isotope fractionation as an indicator for in situ biodegradation of the fuel oxygenates MTBE and tert-amyl methyl ether (TAME). In this study, MTBE utilization was observed in a methanogenic sediment microcosm after a lengthy lag period of about 400 days. MTBE utilization was sustained upon refeeding and subculturing. tert-Butyl alcohol (TBA) was found to accumulate after propagation of cultures. The MTBE-grown cultures also utilized TAME and produced tert-amyl alcohol (TAA). The detection of TBA and TAA indicated that ether bond cleavage was the initial step in degradation for both compounds. Carbon isotope fractionation during anaerobic MTBE and TAME degradation was studied, and isotopic enrichment factors (epsilon) with 95% confidence intervals of -15.6 +/-4.1% and -13.7+/-4.5% were estimated for anaerobic MTBE and TAME degradation, respectively. Addition of 2-bromoethanesulfonic acid, an inhibitor of methanogenesis, substantially prolonged the lag period before transformation, but did not influence carbon isotope fractionation. Our experiment provided strong evidence of significant carbon isotope fractionation during anaerobic MTBE and TAME degradation, demonstrating that this technique can be used as an indicator for in situ MTBE and TAME degradation.

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

    EPA Science Inventory

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

  15. Ether-Bond-Containing Ionic Liquids as Supercapacitor Electrolytes

    PubMed Central

    2013-01-01

    Electrochemical capacitors (ECs) are electrical energy storage devices that have the potential to be very useful in a wide range of applications, especially where there is a large disparity between peak and average power demands. The use of ionic liquids (ILs) as electrolytes in ECs can increase the energy density of devices; however, the viscosity and conductivity of ILs adversely influence the power density of the device. We present experimental results where several ILs containing different cations have been employed as the electrolyte in cells containing mesoporous carbon electrodes. Specifically, the behavior of ILs containing an ether bond in an alkyl side chain are compared with those of a similar structure and size but containing purely alkyl side chains. Using electrochemical impedance spectroscopy and constant current cycling, we show that the presence of the ether bond can dramatically increase the specific capacitance and reduce device resistance. These results have the important implication that such ILs can be used to tailor the physical properties and electrochemical performance of IL-based electrolytes. PMID:24920995

  16. Green mechanochemical oxidative decomposition of powdery decabromodiphenyl ether with persulfate.

    PubMed

    Huang, Aizhen; Zhang, Zhimin; Wang, Nan; Zhu, Lihua; Zou, Jing

    2016-01-25

    A method was developed for efficiently degrading powdery decabromodiphenyl ether (BDE209) by using mechanochemical (MC) activation of persulfate (PS). Characteristic Raman spectra of BDE209 corresponding to CBr and CO bonds were decreased in intensity and finally disappeared as the MC reaction proceeded. The BDE209 removal was influenced by the molar ratio of PS to BDE209, the mass ratio of milling ball to reaction mixtures, the ball size, and the ball rotation speed. Under optimal conditions, the new method could achieve a complete degradation, debromination and mineralization of BDE209 within 3h of milling. However, the degradation removal (or debromination efficiency) was decreased to only 51.7% (15.6%) and 67.8% (31.5%) for the use of CaO and peroxymonosulfate, respectively. The analyses of products demonstrated that once the degradation was initiated, BDE209 molecules were deeply debrominated and fully mineralized in the MC-PS system. The strong oxidizing ability of this system was due to the reactive sulfate radicals generated from the MC-enhanced activation of PS, which was confirmed with electron spin resonance spectroscopy. Because no toxic low brominated polybrominated diphenyl ethers were accumulated as byproducts, the proposed MC oxidative degradation method will have promising applications in the treatment of solid BDE209 at high concentrations. PMID:26474378

  17. Bioremediation of wastewaters with decabromodiphenyl ether by anaerobic granular sludge.

    PubMed

    Ni, Shou-Qing; Wang, Zhibin; Lv, Lu; Liang, Xueyou; Ren, Longfei; Zhou, Qingxin

    2015-04-01

    Facilities adopting anaerobic granular sludge are widely used for the treatment of high strength wastewater, and hence collect many polybrominated diphenyl ethers (PBDEs), especially decabromodiphenyl ether (BDE-209). We initiated a detailed investigation to gain insight into the bioremoval of BDE-209 by anaerobic granules. Influenced by solution pH, ionic strength and temperature, the equilibrium time was ∼6 h and the biosorption amount increased from 0.099 to 1.25 mg/g suspended sludge with the increase of BDE-209 concentrations. Kinetic studies indicate that BDE-209 biosorption on anaerobic granules follows the pseudo second-order kinetic model. Isotherm analysis exhibits that the Langmuir model fits the data at low temperature, while the Freundlich model is appropriate at room temperature. Thermodynamic analysis shows that biosorption followed an endothermic path and was nonspontaneous with negative value of ΔG0. XPS and FTIR spectra confirmed that oxygen and nitrogen atoms notably contributed to BDE-209 binding. PMID:25784301

  18. High exposure of California firefighters to polybrominated diphenyl ethers.

    PubMed

    Park, June-Soo; Voss, Robert W; McNeel, Sandra; Wu, Nerissa; Guo, Tan; Wang, Yunzhu; Israel, Leslie; Das, Rupali; Petreas, Myrto

    2015-03-01

    Concern about persistent organic pollutants (POPs) in Californians prompted the state's biomonitoring program to conduct a study in firefighters, who are occupationally exposed to high levels of POPs. In this work we present serum concentrations of several classes of POPs (polybrominated diphenyl ethers [PBDEs], polychlorinated biphenyls [PCBs], and organochlorine pesticides [OCPs]) in 101 Southern California firefighters. Despite recently reported declining trends of PBDEs in Californians, high levels were measured in firefighters' serum (Σ5PBDEs: median = 59.1 ng/(g of lipid); range = 18.8-714 ng/(g of lipid)) in comparison to other populations in California during the same period. In addition, nearly one-third of subjects had particularly high serum levels of decabromodiphenyl ether (BDE-209), consistent with other recent results in firefighters; this pattern may be a marker of recent firefighting activity. In contrast, serum levels of PCBs and OCPs measured in firefighters' sera were not elevated compared to U.S. levels. Multivariable analysis indicated that lower levels of serum PBDEs were associated with turnout gear cleaning and storage practices after fires. Our study supports the hypothesis that firefighting activities are likely to increase exposure to PBDEs and that good housekeeping and personal hygiene practices may reduce exposure to these compounds. PMID:25643236

  19. Aerobic biotransformation of polybrominated diphenyl ethers (PBDEs) by bacterial isolates.

    PubMed

    Robrock, Kristin R; Coelhan, Mehmet; Sedlak, David L; Alvarez-Cohent, Lisa

    2009-08-01

    Polybrominated diphenyl ethers (PBDEs) are flame retardants that have been used in consumer products and furniture for three decades. Currently, very little is known about their fate in the environment and specifically about their susceptibility to aerobic biotransformation. Here, we investigated the ability of the polychlorinated biphenyl (PCB) degrading bacteria Rhodococcus jostii RHA1 and Burkholderia xenovorans LB400 to transform mono- through hexa-BDEs at ppb levels. We also tested the PBDE transforming abilities of the related strain Rhodococcus sp. RR1 and the ether-degrading Pseudonocardia dioxanivorans CB1190. The two PCB-degrading strains transformed all of the mono- through penta-BDEs and strain LB400 transformed one of the hexa-BDEs. The extent of transformation was inversely proportional to the degree of bromination. Strains RR1 and CB1190 were only able to transform the less brominated mono- and di-BDE congeners. RHA1 released stoichiometric quantities of bromide while transforming mono- and tetra-BDE congeners. LB400 instead converted most of a mono-BDE to a hydroxylated mono-BDE. This is the first report of aerobic transformation of tetra-, penta,- and hexa-BDEs as well as the first report of stoichiometric release of bromide during PBDE transformation.

  20. Novel Ordered Crown Ether-Containing Polyimides for Ion Conduction

    NASA Technical Reports Server (NTRS)

    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.