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Sample records for butyl glycolyl butyl

  1. Butyl methoxy dibenzoylmethane.

    Science.gov (United States)

    Kockler, Jutta; Robertson, Sherryl; Oelgemöller, Michael; Davies, Murray; Bowden, Bruce; Brittain, Harry G; Glass, Beverley D

    2013-01-01

    A comprehensive profile on Butyl methoxy dibenzoylmethane, one of the most commonly used ultraviolet (UV) filters in topical sunscreen products, is prepared. This UV filter, often referred to as Avobenzone, has its main absorbance in the UVA I region of the spectrum and is susceptible to photodegradation. The profile contains the following sections: general information, use and mechanism of action, method of preparation, physical characteristics, methods of analysis, stability, and toxicity. The physical characteristics section includes the melting range, differential scanning calorimetry, partition coefficient, ionization constant, solubility, and UV, infrared, nuclear magnetic resonance ((1)H NMR and (13)C NMR) and mass spectrometry and X-ray powder diffractometry. The method of analysis section in addition to compendial identification and purity and assay methods includes thin-layer gas and high-performance liquid chromatography. The photostability and photostabilization of Butyl methoxy dibenzoylmethane, in addition to its toxicity, are also documented.

  2. Compound list: butylated hydroxyanisole [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available butylated hydroxyanisole BHA 00156 ftp://ftp.biosciencedbc.jp/archive/open-tggates/...LATEST/Human/in_vitro/butylated_hydroxyanisole.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/o...pen-tggates/LATEST/Rat/in_vivo/Liver/Single/butylated_hydroxyanisole.Rat.in_vivo.Liver.Single.zip ftp://ftp....biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/butylated_hydroxyanisole.Rat.in_vivo.Liver.Repeat.zip ...

  3. 21 CFR 182.3173 - Butylated hydroxytoluene.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Butylated hydroxytoluene. 182.3173 Section 182.3173 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives §...

  4. 21 CFR 182.3169 - Butylated hydroxyanisole.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Butylated hydroxyanisole. 182.3169 Section 182.3169 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives §...

  5. 76 FR 59906 - Fluazifop-P-butyl; Pesticide Tolerances

    Science.gov (United States)

    2011-09-28

    ... secondary residues of fluazifop-P-butyl in livestock commodities from consumption of fluazifop-P-butyl... Performance Liquid Chromatography/Ultra-Violet Spectrometry (HPLC/UV)) is available to enforce the tolerance... cover residues of the herbicide fluazifop-P-butyl, including its metabolites and degradates, but...

  6. Intake of butylated hydroxyanisole and butylated hydroxytoluene and stomach cancer risk : results from analyses in the Netherlands : cohort study

    NARCIS (Netherlands)

    Botterweck, A.A.M.; Verhagen, H.; Goldbohm, R.A.; Kleinjans, J.; Brandt, P.A. van den

    2000-01-01

    Both carcinogenic and anticarcinogenic properties have been reported for the synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The association between dietary intake of BHA and BHT and stomach cancer risk was investigated in the Netherlands Cohort Study (NLCS)

  7. 2-(tert-Butyl-4-phenyloxetane

    Directory of Open Access Journals (Sweden)

    Filippo Maria Perna

    2017-02-01

    Full Text Available The two geometric isomers of 2-(tert-butyl-4-phenyloxetane have, for the first time, been prepared starting from the commercially available 4,4-dimethyl-1-phenylpentane-1,3-dione. The latter was reduced with NaBH4 to give a mixture of diastereomeric syn and anti diols which were then stereospecifically cyclized into the corresponding oxetanes with an overall yield for the two steps of 69.6%. The newly synthesized stereoisomeric four-membered oxygenated heterocycles were separated by column chromatography on silica gel and fully spectroscopically characterized.

  8. Organic Semiconductors and Conductors with tert-Butyl Substituents

    Directory of Open Access Journals (Sweden)

    Toshiki Higashino

    2012-08-01

    Full Text Available Tetrathiafulvalene (TTF, pentacene, and quarterthiophene with tert-butyl substituents are synthesized, and the crystal structures and the transistor properties are investigated. The tetracyanoquinodimethane (TCNQ complex of tert-butyl TTF constructs highly one-dimensional segregated columns with tetragonal crystal symmetry.

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

    Directory of Open Access Journals (Sweden)

    Alamdari Reza Fareghi

    2014-01-01

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

  10. Solubilization of meso-carbon microbeads by potassium- or dibutylzinc-promoted butylation and structural analysis of the butylated products; Mesocarbon microbeads no butyl ka ni yoru kayoka to erareta butyl kabutsu no kozo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Murata, S.; Zhang, Y.; Kidena, K.; Nomura, M. [Osaka University, Osaka (Japan). Faculty of Engineering

    1996-10-28

    Tetrahydrofuran (THF) solubility and structure of the butylated products of meso-carbon microbeads (MCMB) were studied experimentally. In experiment, MCMB-A and MCMB-B obtained from two kinds of coal-tar pitch were used as specimens. MCMBs were butylated by BZ method using dibutylzinc-butyl iodide and KT method using K-butyl iodide-THF, and the butylated products were successfully obtained. The butylated products were investigated through THF solubility test, {sup 13}C-NMR measurement and gel permeation chromatography (GPC) measurement. As the experimental result, a BZ method produced the butylated products at a yield of nearly 170%, while a KT method produced them at a yield of nearly 130%. The THF solubility was estimated to be 89-97%. As the study result of molecular weight distributions by GPC measurement of solvent solubles, the molecular weight of raw material MCMB was estimated to be 590-770 in terms of polystyrene. 6 refs., 2 figs., 1 tab.

  11. Phenol Tert-Butylation Catalyzed by Zeolite H-Mordenite

    Institute of Scientific and Technical Information of China (English)

    HAN Sen; LI Zhenhua; ZHANG Kui

    2005-01-01

    Para-tert-butyl phenol (p-TBP) and 2,4-di-tert-butyl phenol (2,4-DTBP) are widely used for the preparation of antioxidants. Zeolite catalysts showed good performance for the synthesis of p-TBP and 2,4-DTBP. In this work, zeolite H-mordenite (HM) catalyst was prepared and the alkylation of phenol with tert-butyl alcohol over zeolite HM catalyst was investigated at different reaction conditions. It is found that increasing temperature enhances the selectivity to p-TBP and the optimum reaction temperature for phenol conversion is 438 K. Increasing flow rate decreases phenol conversion apparently while the selectivity to p-TBP has a little increase. The suitable tert-butyl alcohol/phenol molar ratio is 2. Lower alcohol/phenol molar ratios are beneficial to p-TBP while higher ones are helpful for producing 2,4-DTBP.

  12. Embryolethality of butyl benzyl phthalate in rats

    Energy Technology Data Exchange (ETDEWEB)

    Ema, N.; Itami, T.; Kawasaki, H. (National Inst. Hyg. Science, Osaka (Japan))

    1991-03-15

    The developmental toxicity of butyl benzyl phthalate (BBP) was studied in Wistar rats. Pregnant rats were given BBP at a dosage of 0, 0.25, 0.5, 1.0 or 2.0% in the diet from day 0 to day 20 of pregnancy. Morphological examinations of the fetuses revealed no evidence of teratogenesis. In the 2.0% group, all dams exhibited complete resorption of all the implanted embryos, and their food consumption, body weight gain and adjusted weight gain during pregnancy were markedly lowered. To determine whether the embryolethality was the result of reduced food consumption during pregnancy, a pair-feeding study was performed in which the pregnant rats received the same amount of diet consumed by the 2.0% BBP-treated pregnant rats. The pair-fed and 2.0 % BBP-treated pregnant rats showed significant and comparable reductions in the adjusted weight gain. The number of live fetuses was lowered in the pair-fed group. However, the complete resorption of all the implanted embryos was not found in any of the pair-fed pregnant rats. The data suggest that the embryolethality observed in the 2.0 % BBP-treated pregnant rats is attributable to the effects o dietary BBP.

  13. Cytotoxicity and genotoxicity of butyl cyclohexyl phthalate.

    Science.gov (United States)

    Köksal, Çinel; Nalbantsoy, Ayse; Karabay Yavaşoğlu, N Ülkü

    2016-03-01

    Butyl cyclohexyl phthalate (BCP) is frequently used in personal care products, medical and household applications. The aim of this study is therefore to evaluate possible cytotoxicity and genotoxicity of BCP using in vitro and in vivo assays. The in vitro cytotoxic effect of BCP was investigated on mouse fibroblastic cell line (L929 cells) by MTT assay. The result showed that BCP inhibits cell proliferation in a concentration-dependent manner (IC50 value = 0.29 µg/mL). For genotoxicity assessment, tested concentrations of BCP demonstrated mutagenic activity in the presence of S9 mix with the Salmonella strain TA100 in the Ames test. Results showed that BCP is a secondary mutagenic substance even in low concentrations. The data obtained from 28-days repeated toxicity tests on mice revealed that BCP caused abnormalities of chromosome number, in a dose-dependent manner. Additionally, DNA damage, particularly DNA strand breaks, was assessed by Comet assay. The test result shows that BCP seemed to have genotoxic potential at a high level of exposure.

  14. Microbial degradation of methyl tert-butyl ether and tert-butyl alcohol in the subsurface

    Science.gov (United States)

    Schmidt, Torsten C.; Schirmer, Mario; Weiß, Holger; Haderlein, Stefan B.

    2004-06-01

    The fate of fuel oxygenates such as methyl tert-butyl ether (MTBE) in the subsurface is governed by their degradability under various redox conditions. The key intermediate in degradation of MTBE and ethyl tert-butyl ether (ETBE) is tert-butyl alcohol (TBA) which was often found as accumulating intermediate or dead-end product in lab studies using microcosms or isolated cell suspensions. This review discusses in detail the thermodynamics of the degradation processes utilizing various terminal electron acceptors, and the aerobic degradation pathways of MTBE and TBA. It summarizes the present knowledge on MTBE and TBA degradation gained from either microcosm or pure culture studies and emphasizes the potential of compound-specific isotope analysis (CSIA) for identification and quantification of degradation processes of slowly biodegradable pollutants such as MTBE and TBA. Microcosm studies demonstrated that MTBE and TBA may be biodegradable under oxic and nearly all anoxic conditions, although results of various studies are often contradictory, which suggests that site-specific conditions are important parameters. So far, TBA degradation has not been shown under methanogenic conditions and it is currently widely accepted that TBA is a recalcitrant dead-end product of MTBE under these conditions. Reliable in situ degradation rates for MTBE and TBA under various geochemical conditions are not yet available. Furthermore, degradation pathways under anoxic conditions have not yet been elucidated. All pure cultures capable of MTBE or TBA degradation isolated so far use oxygen as terminal electron acceptor. In general, compared with hydrocarbons present in gasoline, fuel oxygenates biodegrade much slower, if at all. The presence of MTBE and related compounds in groundwater therefore frequently limits the use of in situ biodegradation as remediation option at gasoline-contaminated sites. Though degradation of MTBE and TBA in field studies has been reported under oxic

  15. Pressure-induced crystallization of 1-butyl-3-methylimidazolium hexafluorophosphate

    Science.gov (United States)

    Shigemi, Machiko; Takekiyo, Takahiro; Abe, Hiroshi; Yoshimura, Yukihiro

    2013-03-01

    We have investigated the pressure-induced crystallization of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) associated with the conformational changes of [bmim]+ by Raman spectroscopy. [bmim]+ has trans-trans and gauche-trans (GT) conformers of the butyl side chain at ambient pressure. Our result revealed that liquid to solid-phase transition occurs at 0.2-0.4 GPa region, where the GT conformer becomes dominant. We found that the GT dominant state continues up to 4 GPa.

  16. Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

    2015-04-10

    Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

  17. IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) ...

    Science.gov (United States)

    The IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) was released for external peer review in April 2017. EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis supporting the ETBE assessment and release a final report of their review. Information regarding the peer review can be found on the SAB website. EPA is conducting an Integrated Risk Information System (IRIS) health assessment for Ethyl Tertiary Butyl Ether (ETBE). The outcome of this project is a Toxicological Review and IRIS Summary for ETBE that will be entered into the IRIS database.

  18. A Study of the Teratogenicity of Butylated Hydroxyanisole on Rabbits

    DEFF Research Database (Denmark)

    Hansen, Ernst; Meyer, Otto A.

    1978-01-01

    A teratogenicity study on butylated hydroxyanisole (BHA) was carried out in SPF New Zealand White rabbits. BHA was given by gavage from day 7–18 of the gestation period in doses of 0, 50, 200 and 400 mg/kg body wt./day. The fetuses were removed on day 28. No effect related to the treatment with BHA...

  19. 27 CFR 21.100 - n-Butyl alcohol.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false n-Butyl alcohol. 21.100 Section 21.100 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 §...

  20. 27 CFR 21.101 - tert-Butyl alcohol.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false tert-Butyl alcohol. 21.101 Section 21.101 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 §...

  1. Enhanced Heterogeneous Catalytic Conversion of Furfuryl Alcohol into Butyl Levulinate

    NARCIS (Netherlands)

    Carà, P.D..; Ciriminna, R.; Shiju, N.R.; Rothenberg, G.; Pagliaro, M.

    2014-01-01

    We study the catalytic condensation of furfuryl alcohol with 1-butanol to butyl levulinate. A screening of several commercial and as-synthesized solid acid catalysts shows that propylsulfonic acid-functionalized mesoporous silica outperforms the state-of-the-art phosphotungstate acid catalysts. The

  2. 76 FR 82152 - Cyhalofop-butyl; Pesticide Tolerances

    Science.gov (United States)

    2011-12-30

    ... observed following subchronic or chronic exposure to cyhalofop-butyl included hyperplasia of the stomach... exposure from drinking water. The Agency used screening level water exposure models in the dietary exposure...://www.epa.gov/oppefed1/models/water/index.htm . Based on the Tier 1 Rice Model and...

  3. Electrical Properties of n-Butyl Acrylate-Grafted Polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.R.; Oh, W.J.; Suh, K.S. [Korea University (Korea, Republic of)

    1997-04-01

    The electrical properties of n-butyl acrylate-grafted polyethylene (PE-g-nBA) were investigated. In PE-g-nBA, hetero charge founded in LDPE slightly increased due to the nBA grafting. Conduction currents decreased with the increase of nBA graft ratio. AC breakdown strength increased and water treeing length decreased with the increase of graft ratio in PE-g-nBA. (author). 4 refs., 6 figs.

  4. Tris(tert-butyl isocyanide-κCcarbonylnickel(0

    Directory of Open Access Journals (Sweden)

    Wolfgang Imhof

    2008-08-01

    Full Text Available The title compound, [Ni(C5H9N3(CO], was prepared from Ni(CO4 and a tenfold excess of tert-butyl isocyanide. It crystallizes with two symmetry-independent molecules per asymmetric unit. The central Ni atom of each independent molecule has a nearly perfect tetrahedral coordination environment, comprising one carbon monoxide and three isocyanide ligands. The title compound is the first structurally characterized Ni0 compound with a mixed CO/RNC coordination.

  5. POLYMERIZATION OF BUTYL METHACRYLATE BY IRON PYRIDINEBISIMINE COMPLEXES

    Institute of Scientific and Technical Information of China (English)

    Jing-yu Liu; Yan-guo Li; Yi Zheng; Yue-sheng Li

    2005-01-01

    Fe(Ⅱ) pyridinebisimine complexes activated with trialkylaluminium or modified methylaluminoxane (MMAO) as catalysts were employed for the polymerization of butyl methacrylate (BMA). Polymer yields, catalytic activities and molecular weights as well as molecular weight distributions of BMA can be controlled over a wide range by varying the reaction parameters such as cocatalyst, A1/Fe molar ratio, monomer/catalyst molar ratio, monomer concentration and reaction yield could reach 99.1% under optimum condition.

  6. Enantioselective degradation and chiral stability of the herbicide fluazifop-butyl in soil and water.

    Science.gov (United States)

    Qi, Yanli; Liu, Donghui; Luo, Mai; Jing, Xu; Wang, Peng; Zhou, Zhiqiang

    2016-03-01

    The stereoselective degradation and transformation of the enantiomers of the herbicide fluazifop-butyl in soil and water were studied to investigate the environmental behavior and chiral stability of the optical pure product. Its main chiral metabolite fluazifop was also monitored. LC/MS/MS with Chiralpak IC chiral column was used to separate the enantiomers of fluazifop-butyl and fluazifop. Validated enantioselective residue analysis methods were established with recoveries ranging from 77.1 to 115.4% and RSDs from 0.85 to 8.9% for the enantiomers. It was found the dissipation of fluazifop-butyl was rapid in the three studied soils (Beijing, Harbin and Anhui soil), and the degradation half-lives of the enantiomers ranged from 0.136 to 2.7 d. Enantioselective degradations were found in two soils. In Beijing soil, R-fluazifop-butyl was preferentially degraded leading to relative enrichment of S-enantiomer, but in Anhui soil, S-fluazifop-butyl dissipated faster. There was no conversion of the R-fluazifop-butyl into S-fluazifop-butyl or vice versa in the soils. The formation of fluazifop in the soils was rapidly accompanied with the fast degradation of fluazifop-butyl, and the enantioselectivity and the transformation of S-fluazifop to R-fluazifop were found. The degradation of fluazifop-butyl in water was also quick, with half-lives of the enantiomers ranging from 0.34 to 2.52 d, and there was no significant enantioselectivity of the degradation of fluazifop-butyl and the formation of fluazifop. The effects of pH on the degradation showed fluazifop-butyl enantiomers degraded faster in alkaline conditions. This study showed an evidence of enantioselective behavior and enantiomerization of the chiral herbicide fluazifop-butyl.

  7. Inducing PLA/starch compatibility through butyl-etherification of waxy and high amylose starch.

    Science.gov (United States)

    Wokadala, Obiro Cuthbert; Emmambux, Naushad Mohammad; Ray, Suprakas Sinha

    2014-11-04

    In this study, waxy and high amylose starches were modified through butyl-etherification to facilitate compatibility with polylactide (PLA). Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy and wettability tests showed that hydrophobic butyl-etherified waxy and high amylose starches were obtained with degree of substitution values of 2.0 and 2.1, respectively. Differential scanning calorimetry, tensile testing, and scanning electron microscopy (SEM) demonstrated improved PLA/starch compatibility for both waxy and high amylose starch after butyl-etherification. The PLA/butyl-etherified waxy and high amylose starch composite films had higher tensile strength and elongation at break compared to PLA/non-butyl-etherified composite films. The morphological study using SEM showed that PLA/butyl-etherified waxy starch composites had a more homogenous microstructure compared to PLA/butyl-etherified high amylose starch composites. Thermogravimetric analysis showed that PLA/starch composite thermal stability decreased with starch butyl-etherification for both waxy and high amylose starches. This study mainly demonstrates that PLA/starch compatibility can be improved through starch butyl-etherification.

  8. tert-Butyl N-(thiophen-2-ylcarbamate

    Directory of Open Access Journals (Sweden)

    Gene C. Hsu

    2013-09-01

    Full Text Available In the title compound, C9H13NO2S, the dihedral angle between the thiophene ring and the carbamate group is 15.79 (14°. In the crystal structure, intramolecular C—H...O interactions in tandem with the tert-butyl groups render the packing of adjacent molecules in the [001] direction nearly perpendicular [the angle between adjacent thiophene rings is 74.83 (7°]. An intermolecular N—H...O hydrogen bond gives rise to a chain extending along [001]. The crystal studied was found to be a racemic twin.

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

    Directory of Open Access Journals (Sweden)

    S. B. Mortazavi

    2005-01-01

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

  10. Antisickling activity of butyl stearate isolated from Ocimum basilicum (Lamiaceae)

    Institute of Scientific and Technical Information of China (English)

    Dorothe Dinangayi Tshilanda; Pius Tshimankinda Mpiana; Damase Nguwo Vele Onyamboko; Blaise Mavinga Mbala; Koto-te-Nyiwa Ngbolua; Damien Sha Tshibey Tshibangu; Matthieu Kokengo Bokolo; Kalulu Muzele Taba; Teddy Kabeya Kasonga

    2014-01-01

    Objective: To perform phytochemical analyses on the leaves of Ocimum basilicum L. (O. basilicum), to elucidate the structure of isolate and then perform the antisickling activity on the crude extract and on the isolate. Methods:The Emmel test performed on the acidified methanolic extract of this plant was used to evaluate the antisickling activity. The structure characterization of the active compound was performed using chromatographic techniques for the separation and the spectroscopic ones for structure elucidation (1H-NMR, 13C-NMR, COSY, HMBC). Results: The chemical screening on the crude extract revealed the presence of polyphenols (flavonoids, anthocyanins, leucoanthocyanins, tannins, quinones) alkaloids, saponins, triterpenoids and steroids. The obtained extract after evaporation yielded 34.50 g (11.5%) out of 300 g of powdered leaves of O. basilicum. The acidified methanolic extract and butyl stearate showed an interesting antisickling activity. Conclusions:The acidified methanolic extract and butyl stearate from O. basilicum displayed a good antisickling activity. To the best of our knowledge, this is the first time to report the antisickling activity of this compound in this plant. The synthesized compound presented the same spectroscopic characteristics than the natural one and the antisickling activities of its derivatives are understudying.

  11. 76 FR 38026 - Diethylene Glycol Mono Butyl Ether; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2011-06-29

    ... butyl ether, also a glycol ether differing in only one ethyl group from DEGBE. These data were used to... monobutyl ether, also a glycol ether differing only in one ethyl group. This data was used to assess the... AGENCY 40 CFR Part 180 Diethylene Glycol Mono Butyl Ether; Exemption From the Requirement of a...

  12. Visible-light promoted degradation of the commercial antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT): a kinetic study.

    Science.gov (United States)

    Criado, Susana; Allevi, Carolina; Ceballos, Claudio; García, Norman A

    2007-01-01

    Visible-light photo-irradiation of the commercial phenolic antioxidants (PhAs) butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), in the presence of vitamin B2 (riboflavin, Rf), in methanolic solutions and under aerobic conditions, results in the photo-oxidation of the PhAs. The synthetic dye photosensitiser Rose Bengal was also employed for auxiliary experiments. With concentrations of riboflavin and PhAs of ca. 0.02 mM and pigment is generated through an electron transfer process from BHT, with the subsequent production of superoxide anion radical (O2*-) by reaction with dissolved molecular oxygen. In parallel, the species singlet molecular oxygen, O2(1delta(g)), is also generated. Both reactive oxygen species produce the photodegradation of BHT. In the case of BHA, the lack of any effect exerted by superoxide dismutase drives out a significant participation of a O2(*-)-mediated mechanism. BHA mainly interacts with O2(1delta(g)) and exhibits a desirable property as an antioxidant--a relatively high capacity for O2(1delta(g)) de-activation and a low photodegradation efficiency by the oxidative species. Electrochemical determinations support the proposed photodegradative mechanism.

  13. Synthesis of Highly Porous Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) Asymmetric Membranes

    KAUST Repository

    Xie, Yihui

    2016-03-24

    For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymers membranes used in this method, which were mainly based on polystyrene blocks. Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) (PtBA30k-b-PSU14k-b-PtBA30k) with a low polydispersity of 1.4 was synthesized by combining step-growth condensation and RAFT polymerization. Various advanced electron microscopies revealed that PtBA30k-b-PSU14k-b-PtBA30k assembles into worm-like cylindrical micelles in DMAc and adopts a “flower-like” arrangement with the PSU central block forming the shell. Computational modeling described the mechanism of micelle formation and morphological transition. Asymmetric nanostructured membranes were obtained with a highly porous interconnected skin layer and a sublayer with finger-like macrovoids. Ultrafiltration tests confirmed a water permeance of 555 L m-2 h-1 bar-1 with molecular weight cut-off of 28 kg/mol. PtBA segments on the membrane surface were then hydrolyzed and complexed with metals, leading to cross-linking and enhancement of antibacterial capability.

  14. Vapor Pressures of Di-n-Butyl Phthalate and Di-iso-Butyl Hexahydrophthalate at Reduced Pressures

    Institute of Scientific and Technical Information of China (English)

    齐欣; 徐立勇; 高正红; 刘志华

    2004-01-01

    In this paper the measured values of the vapor pressures by ebulliometer method of two important maleic anhydride recovery solvents, di-n-butyl phthalate (DBP) and di-iso-butyl hexahydrophthalate (DIBE), between 0.63-17.79 kPa and 0.49-30.95 kPa,are reported respectively.A comparison of the data of DBP with the published data has been made, which shows good consistency. For the convenient use of these vapor pressures, Cragoe equation, Antoine equation and Kirchhoff equation are selected to correlate them. The correlating results show that Antoine equation is the best one of the three equations to fit for the vapor pressures of the two solvents. According to Clausius-Clapeyron equation, the linear relationship between natural logarithm of pressure and reciprocal of temperature is used to calculate the molar latent heats of evaporation of the two organic solvents. The molar latent heats of evaporation of DBP and DIBE are 75.1 kJ/mol and 67.7 kJ/mol, respectively.

  15. Recovering/recycling of butyl and halogenated butyl rubber via ionizing radiation; Recuperacao/reciclagem de compostos de borrachas butilica e halobutilica por meio de radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Sandra Regina Scagliusi

    2013-07-01

    Polymeric materials (plastics and rubbers) attain a continuous and raising proportion of urban and industrial scraps discarded in landfills; their impact on environment are more and more concerning. The implementation of new technologies in order to reduce impacts of plastic waste on the environment, at an effective cost, proved to be a great problem, due to inherent complexity for polymers re-using. Ionizing radiation is capable to modify structure and properties of polymeric material. Butyl and halobutyl rubbers have been used within a comprehensive scale, applications such as tires spare parts and diverse artifacts. The major high energy photon effect, as gamma-rays in butyl and halo butyl rubbers consists in free-radicals generation along changes in mechanical properties.This work aims to the development of controlled degradation processes (devulcanization) of butyl and halo butyl (chlorine and bromine) rubbers, in order to characterize their availability for transformation and modification of properties. Experimental results obtained showed that butyl and halobutyl rubbers,irradiated at 25 kGy and further sheared, are able to be used as an initial point for mixtures with pristine. (author)

  16. Theoretical calculations of hyperfine coupling constants for muoniated butyl radicals.

    Science.gov (United States)

    Chen, Ya Kun; Fleming, Donald G; Wang, Yan Alexander

    2011-04-01

    The hyperfine coupling constants (HFCCs) of all the butyl radicals that can be produced by muonium (Mu) addition to butene isomers (1- and 2-butene and isobutene) have been calculated, to compare with the experimental results for the muon and proton HFFCs for these radicals reported in paper II (Fleming, D. G.; et al. J. Phys. Chem. A 2011, 10.1021/jp109676b) that follows. The equilibrium geometries and HFCCs of these muoniated butyl radicals as well as their unsubstituted isotopomers were treated at both the spin-unrestricted MP2/EPR-III and B3LYP/EPR-III levels of theory. Comparisons with calculations carried out for the EPR-II basis set have also been made. All calculations were carried out in vacuo at 0 K only. A C-Mu bond elongation scheme that lengthens the equilibrium C-H bond by a factor of 1.076, on the basis of recent quantum calculations of the muon HFCCs of the ethyl radical, has been exploited to determine the vibrationally corrected muon HFCCs. The sensitivity of the results to small variations around this scale factor was also investigated. The computational methodology employed was "benchmarked" in comparisons with the ethyl radical, both with higher level calculations and with experiment. For the β-HFCCs of interest, compared to B3LYP, the MP2 calculations agree better with higher level theories and with experiment in the case of the eclipsed C-Mu bond and are generally deemed to be more reliable in predicting the equilibrium conformations and muon HFCCs near 0 K, in the absence of environmental effects. In some cases though, the experimental results in paper II demonstrate that environmental effects enhance the muon HFCC in the solid phase, where much better agreement with the experimental muon HFCCs near 0 K is found from B3LYP than from MP2. This seemingly better level of agreement is probably fortuitous, due to error cancellations in the DFT calculations, which appear to mimic these environmental effects. For the staggered proton HFCCs of the

  17. Interactions between water and 1-butyl-1-methylpyrrolidinium ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Fadeeva, Tatiana A.; DeVine, Jessalyn A.; Castner, Edward W., E-mail: ed.castner@rutgers.edu [Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 (United States); Husson, Pascale [CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, BP 80026, F-63171 Aubière (France); Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); Costa Gomes, Margarida F. [CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, BP 80026, F-63171 Aubière (France); Greenbaum, Steven G. [Department of Physics and Astronomy, Hunter College, CUNY, New York, New York 10065 (United States)

    2015-08-14

    We report experimental results on the diffusivity of water in two ionic liquids obtained using the pulsed-gradient spin-echo NMR method. Both ionic liquids have the same cation, 1-butyl-1-methylpyrrolidinium, but different trifluoromethyl-containing anions. One has a strongly hydrophobic anion, bis(trifluoromethylsulfonyl)amide, while the second has a hydrophilic anion, trifluoromethylsulfonate. Transport of water in these ionic liquids is much faster than would be predicted from hydrodynamic laws, indicating that the neutral water molecules experience a very different friction than the anions and cations at the molecular level. Temperature-dependent viscosities, conductivities, and densities are reported as a function of water concentration to further analyze the properties of the ionic liquid-water mixtures. These results on the properties of water in ionic liquids should be of interest to researchers in diverse areas ranging from separations, solubilizing biomass and energy technologies.

  18. Interactions between water and 1-butyl-1-methylpyrrolidinium ionic liquids.

    Science.gov (United States)

    Fadeeva, Tatiana A; Husson, Pascale; DeVine, Jessalyn A; Costa Gomes, Margarida F; Greenbaum, Steven G; Castner, Edward W

    2015-08-14

    We report experimental results on the diffusivity of water in two ionic liquids obtained using the pulsed-gradient spin-echo NMR method. Both ionic liquids have the same cation, 1-butyl-1-methylpyrrolidinium, but different trifluoromethyl-containing anions. One has a strongly hydrophobic anion, bis(trifluoromethylsulfonyl)amide, while the second has a hydrophilic anion, trifluoromethylsulfonate. Transport of water in these ionic liquids is much faster than would be predicted from hydrodynamic laws, indicating that the neutral water molecules experience a very different friction than the anions and cations at the molecular level. Temperature-dependent viscosities, conductivities, and densities are reported as a function of water concentration to further analyze the properties of the ionic liquid-water mixtures. These results on the properties of water in ionic liquids should be of interest to researchers in diverse areas ranging from separations, solubilizing biomass and energy technologies.

  19. Picosecond photoexcitation dynamics in poly(3-butyl-thiophene) films

    Science.gov (United States)

    Frolov, S. V.; Wei, X.; Gellermann, W.; Vardeny, Z. V.; Ehrenfreund, E.

    1998-02-01

    We have studied photoexcitation dynamics in thin films of poly(3-butyl-thiophene) [P3BT] using ps transient and cw photomodulation techniques, streak camera imaging, electroabsorption and optically detected magnetic resonance spectroscopies. We have determined that intrachain excitons are the primary photoexcitations with a characteristic transient photomodulation spectrum consisting of two photoinduced absorption bands in the near IR spectral range and a broad stimulated emission band in the visible spectral region. The photogenerated excitons are relatively short-lived (150 ps) and can subsequently decay into polaron pairs and triplets, which are longer-lived excitations with lifetimes of order ms. We do not find stimulated emission in very thin P3BT films and this is attributed to high defect concentration close to the film surface.

  20. Modeling Low Density Polyethylene with Precisely Placed Butyl Branches

    Science.gov (United States)

    Rojas, Giovanni; Wagener, Kenneth B.

    Polyethylene (PE) is a commodity produced on a massive scale and also is one of the most studied macromolecules. Crystallinity can be controlled by copolymerizing ethylene with α-olefins, producing a wide range of material responses. Physical properties of PE, obtained via α olefin copolymerization, depend on the branch content that is directly related to the comonomer incorporation into the PE backbone. Materials with unknown primary structures are produced via chaingrowth chemistry, because unwanted side reactions generate defects in the main backbone that alter the morphological behavior and thermal response. Acyclic diene metathesis (ADMET) polymerization/hydrogenation methodology produce perfect sequenced copolymers of ethylene with α-olefins. Synthesis and thermal properties of PE with butyl branches precisely placed along the polymer backbone using ADMET chemistry is described within.

  1. tert-Butyl 2-methyl-2-(4-methylbenzoylpropanoate

    Directory of Open Access Journals (Sweden)

    Graham B. Gould

    2010-02-01

    Full Text Available The title compound, C16H22O3, is bent with a dihedral angle of 75.3 (1° between the mean planes of the benzene ring and a group encompassing the ester functionality (O=C—O—C. In the crystal, the molecules are linked into infinite chains held together by weak C—H...O hydrogen-bonded interactions between an H atom on the benzene ring of one molecule and an O atom on the ketone functionality of an adjacent molecule. The chains are arranged with neighbouring tert-butyl and dimethyl groups on adjacent chains exhibiting hydrophobic stacking, with short C—H...H—C contacts (2.37 Å between adjacent chains

  2. Synthesis and reinforcement of peroxide-cured butyl rubber thermosets

    Science.gov (United States)

    Rodrigo, Antonio Cillero

    Isobutylene-rich elastomers provide the oxidative stability and impermeability required by many industrial applications. Halogenated derivatives support a wide range of chemical modification processes that can overcome most performance limitations. This research involves the modification of brominated butyl rubber (BIIR) to introduce peroxide-curable functionality in addition to aminotrialkoxysilyl groups that improve interactions with siliceous fillers, and anthraquinone functionality that serves as a polymer-bound chromophore. The thesis also describes detailed studies of the influence of counter anions on imidazolium ionomer derivatives of brominated poly(isobutylene-co-p-methylstyrene) (BIMS). Exchanging bromide with dodecyl sulfate, styrene sulfonate and montmorillonite clay platelets provided new ionomer thermosets whose rheological, tensile and adhesive properties varied considerably from their parent material.

  3. Hydrolysis of tert-butyl formate: Kinetics, products, and implications for the environmental impact of methyl tert-butyl ether

    Science.gov (United States)

    Church, Clinton D.; Pankow, James F.; Tratnyek, Paul G.

    1999-01-01

    Asessing the environmental fate of methyl tert-butyl ether (MTBE) has become a subject of renewed interest because of the large quantities of this compound that are being used as an oxygenated additive in gasoline. Various studies on the fate of MTBE have shown that it can be degraded to tert-butyl formate (TBF), particularly in the atmosphere. Although it is generally recognized that TBF is subject to hydrolysis, the kinetics and products of this reaction under environmentally relevant conditions have not been described previously. In this study, we determined the kinetics of TBF hydrolysis as a function of pH and temperature. Over the pH range of 5 to 7, the neutral hydrolysis pathway predominates, with kN = (1.0 ± 0.2) × 10−6/s. Outside this range, strong pH effects were observed because of acidic and basic hydrolyses, from which we determined that kA = (2.7 ± 0.5) × 10−3/(M·s) and kB = 1.7 ± 0.3/(M·s). Buffered and unbuffered systems gave the same hydrolysis rates for a given pH, indicating that buffer catalysis was not significant under the conditions tested. The activation energies corresponding to kN, kA, and kBwere determined to be 78 ± 5, 59 ± 4, and 88 ±11 kJ/mol, respectively. In all experiments, tert-butyl alcohol was found at concentrations corresponding to stoichiometric formation from TBF. Based on our kinetics data, the expected half-life for hydrolysis of TBF at pH = 2 and 4°C (as per some standard preservation protocols for water sampling) is 6 h. At neutral pH and 22°C, the estimated half-life is 5 d, and at pH = 11 and 22°C, the value is only 8 min.

  4. Gamma-radiation effect on thermal ageing of butyl rubber compounds

    Energy Technology Data Exchange (ETDEWEB)

    Scagliusi, Sandra R.; Cardoso, Elizabeth C.L.; Lugao, Ademar B., E-mail: srscagliusi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Butyl rubber has a comprehensive use in sealing systems, especially in tires inner tubes, due to their low permeability to gases. So, it is required that butyl rubber compounds show a better performance, more and more. Butyl rubber is provided with excellent mechanical properties and oxidation resistance. Besides showing these properties, radiation exposures impart modifications in physical-chemical and morphological properties on butyl rubber materials. When exposed to gamma-radiation, rubbers suffer changes in their mechanical and physical properties, caused by material degradation. The major radiation effect in butyl rubbers is chain scission; besides, ageing promotes too the same effect with further build-up of free radicals. This work aims to the study of gamma-radiation in physical-chemical properties of butyl rubber subjected to thermal ageing. Doses used herein were: 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 KGy. Samples were evaluated before and after ageing according to traditional essays, such as: hardness, tensile strength and elongation at break. From accomplished assessments it is possible to affirm that at doses higher than 50 kGy it was observed a sharp decreasing in butyl rubber physical-chemical properties, before and after exposure to ageing. (author)

  5. Thyroid disruption by Di-n-butyl phthalate (DBP and mono-n-butyl phthalate (MBP in Xenopus laevis.

    Directory of Open Access Journals (Sweden)

    Ouxi Shen

    Full Text Available BACKGROUND: Di-n-butyl phthalate (DBP, a chemical widely used in many consumer products, is estrogenic and capable of producing seriously reproductive and developmental effects in laboratory animals. However, recent in vitro studies have shown that DBP and mono-n-butyl phthalate (MBP, the major metabolite of DBP, possessed thyroid hormone receptor (TR antagonist activity. It is therefore important to consider DBP and MBP that may interfere with thyroid hormone system. METHODOLOGY/PRINCIPAL FINDINGS: Nieuwkoop and Faber stage 51 Xenopus laevis were exposed to DBP and MBP (2, 10 or 15 mg/L separately for 21 days. The two test chemicals decelerated spontaneous metamorphosis in X. laevis at concentrations of 10 and 15 mg/L. Moreover, MBP seemed to possess stronger activity. The effects of DBP and MBP on inducing changes of expression of selected thyroid hormone response genes: thyroid hormone receptor-beta (TRβ, retinoid X receptor gamma (RXRγ, alpha and beta subunits of thyroid-stimulating hormone (TSHα and TSHβ were detected by qPCR at all concentrations of the compounds. Using mammalian two-hybrid assay in vitro, we found that DBP and MBP enhanced the interactions between co-repressor SMRT (silencing mediator for retinoid and thyroid hormone receptors and TR in a dose-dependent manner, and MBP displayed more markedly. In addition, MBP at low concentrations (2 and 10 mg/L caused aberrant methylation of TRβ in head tissue. CONCLUSIONS: The current findings highlight potential disruption of thyroid signalling by DBP and MBP and provide data for human risk assessment.

  6. Voltammetric Determination of Dinonyl Diphenylamine and Butylated Hydroxytoluene in Mineral and Synthetic Oil.

    Science.gov (United States)

    Xiang, Yaling; Qian, Xuzheng; Hua, Meng; Cheng, Bingxue; Chen, Wu; Li, Jian

    2016-07-02

    A method is reported for the determination of diphenylamine and butylated hydroxytoluene in mineral and synthetic oil. The procedure used differential pulse voltammetry with a glassy carbon electrode. This method was then used for determining these antioxidants in supporting electrolyte consisting of dilute sulfuric acid and sodium dodecyl sulfonate in ethanol. Anodic peaks were obtained for both analytes. Oxidation peaks at 250 mV were observed from a mixture of butylated hydroxytoluene and dinonyl diphenylamine, allowing their simultaneous determination. This approach was successfully used for the determination of dinonyl diphenylamine and butylated hydroxytoluene in fortified mineral and synthetic oils with good accuracy and precision.

  7. Ethyl tertiary-butyl ether: a toxicological review.

    Science.gov (United States)

    McGregor, Douglas

    2007-05-01

    A number of oxygenated compounds (oxygenates) are available for use in gasoline to reduce vehicle exhaust emissions, reduce the aromatic compound content, and avoid the use of organo-lead compounds, while maintaining high octane numbers. Ethyl tertiary-butyl ether (ETBE) is one such compound. The current use of ETBE in gasoline or petrol is modest but increasing, with consequently similar trends in the potential for human exposure. Inhalation is the most likely mode of exposure, with about 30% of inhaled ETBE being retained by the lungs and distributed around the body. Following cessation of exposure, the blood concentration of ETBE falls rapidly, largely as a result of its metabolism to tertiary-butyl alcohol (TBA) and acetaldehyde. TBA may be further metabolized, first to 2-methyl-1,2-propanediol and then to 2-hydroxyisobutyrate, the two dominant metabolites found in urine of volunteers and rats. The rapid oxidation of acetaldehyde suggests that its blood concentration is unlikely to rise above normal as a result of human exposure to sources of ETBE. Single-dose toxicity tests show that ETBE has low toxicity and is essentially nonirritant to eyes and skin; it did not cause sensitization in a maximization test in guinea pigs. Neurological effects have been observed only at very high exposure concentrations. There is evidence for an effect of ETBE on the kidney of rats. Increases in kidney weight were seen in both sexes, but protein droplet accumulation (with alpha(2u)-globulin involvement) and sustained increases in cell proliferation occurred only in males. In liver, centrilobular necrosis was induced in mice, but not rats, after exposure by inhalation, although this lesion was reported in some rats exposed to very high oral doses of ETBE. The proportion of liver cells engaged in S-phase DNA synthesis was increased in mice of both sexes exposed by inhalation. ETBE has no specific effects on reproduction, development, or genetic material. Carcinogenicity studies

  8. n-Butyl Pyridinium Nitrate as a Reusable Ionic Liquid Medium for Knoevenagel Condensation

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The Knoevenagel condensation of carbonyl substrates with active methylene compounds proceeds smoothly with ammonium acetate as catalyst in n-butyl pyridinium nitrate to afford the desired products of good purity in moderate yields.

  9. Endoscopic Injection of a Ruptured Duodenal Varix with N-butyl-2-cyanoacrylate

    Directory of Open Access Journals (Sweden)

    Paulo Salgueiro

    2014-04-01

    Conclusions: The presented case supports endoscopic injection sclerotherapy with N-butyl-2-cyanoacrylate as a treatment option for ruptured duodenal varices that, despite being a rare event, when it occurs, is often fatal.

  10. The reclaiming of butyl rubber and in-situ compatibilization of thermoplastic elastomer by power ultrasound

    Science.gov (United States)

    Feng, Wenlai

    This is a study of the continuous ultrasound aided extrusion process for the in-situ compatibilization of isotactic polypropylene (iPP)/ethylene-propylene diene rubber (EPDM) thermoplastic elastomer (TPE) using a newly developed ultrasonic treatment reactor. The rheological, mechanical properties and morphology of the TPE with and without ultrasonic treatment were studied. In-situ compatibilization in the ultrasonically treated blends was observed as evident by their more stable morphology after annealing, improved mechanical properties and IR spectra. The obtained results indicated that ultrasonic treatment induced the thermo-mechanical degradations and led to the possibility of enhanced molecular transport and chemical reactions at the interfaces. Processing conditions were established for enhanced in situ compatibilization of the PP/EPDM TPE. The ultrasonic treatments of butyl rubber gum and ultrasonic devulcanization of butyl rubber, tire-curing bladder during extrusion using a grooved barrel ultrasonic reactor were carried out. The ultrasonic treatment of gum caused degradation of the polymer main chain leading to lower molecular weight, broader molecular weight distribution, less unsaturation and changes in physical properties. The devulcanization of butyl rubber was successfully accomplished only at severe conditions of ultrasonic treatment. The mechanical properties of vulcanizates prepared from devulcanized butyl rubber are comparable to that of the virgin vulcanizate. The molecular characterization of sol fraction of devulcanized butyl rubber showed the devulcanization and degradation of butyl rubber occurred simultaneously. 1H NMR transverse relaxation was also used to study butyl rubber gum before and after ultrasonic treatment, and ultrasonically devulcanized unfilled butyl rubber. The T2 relaxation decays were successfully described using a two-component model. The recyclability of tire-curing bladder was also investigated. Gel fraction, crosslink

  11. Etude de l'effet du gonflement par les solvants sur les proprietes du caoutchouc butyle

    Science.gov (United States)

    Nohile, Cedrick

    Polymers and in particular elastomers are widely used for personal protective equipment against chemical and biological hazards. Among them, butyl rubber is one of the most effective elastomers against chemicals. However, if this rubber has a very good resistance to a wide range of them, it is sensitive to non polar solvents. These solvents will easily swell the material and may dramatically affect its properties. This situation may involve a large risk for. butyl rubber protective equipment users. It is thus essential to improve the understanding of the effect of solvents on the properties of butyl rubber. The research that was carried out had two objectives: to identify the parameters controlling the resistance of butyl rubber to solvents and to study the effect of swelling on the properties of butyl rubber. The results show that the resistance of butyl rubber to solvents appears to be controlled by three main parameters: the chemical class of the solvent, its saturation vapor pressure and its molar volume. In addition, swelling affects butyl rubber mechanical properties in a permanent way. The effects can be attributed to the extraction of plasticizers by the solvent and to the degradation of the physico-chemical structure of the polymer network. This chemical degradation was linked to a phenomenon of differential swelling which seems to be controlled by the solvent flow inside the material. These results question some general beliefs within the field of protection against chemical risks. They also open new perspectives for the development of predictive tools relative to the behavior of butyl rubber in the presence of solvents

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

    Directory of Open Access Journals (Sweden)

    A. Mesdaghinia

    2007-09-01

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

  13. Biodegradation of methyl tert-butyl ether by Kocuria sp.

    Directory of Open Access Journals (Sweden)

    Kiković Dragan D.

    2012-01-01

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

  14. Dietary Exposure to Benzyl Butyl Phthalate in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; JIANG Ding Guo; SUI Hai Xia; WU Ping Gu; LIU Ai Dong; YANG Da Jin; LIU Zhao Ping; SONG Yan; LI Ning

    2016-01-01

    ObjectiveBenzyl butyl phthalate (BBP) is a plasticizer used in food contact materials. Dietary exposure to BBP might lead to reproduction and developmental damages to human. The present paper was aimed to assess the health risk of BBP dietary exposure in Chinese population. MethodsThe BBP contents were detected in 7409 food samples from 25 foodcategories by gas chromatography-mass spectrometry operated in selected ion monitoring (SIM) mode. The dietary exposures of BBP in different age and sex groups were estimated by combining the content data with food consumption data derived from 2002 China National Nutrient and Health Survey, and evaluated according to the tolerable daily intake (TDI) of BBP established by European Food safety Agency. ResultsIt was found that BBP was undetectable in most samples and the highest level was 1.69 mg/kg detected in a vegetable oil sample. The average dietary exposure of BBP in people aged≥2 years was 1.03 μg/kgbw perday and the highest average exposure was found in 2-6 years old children (1.98 μg/kg bw perday). The BBP exposure in 7-12 months old children excessed 10% of tolerable daily intake (TDI) in worst scenario. ConclusionThe health risk of BBP dietary exposure in Chinese population is low and, considering BBP alone, there is no safety concern.

  15. Embolotherapy using N-butyl cyanoacrylate for abdominal wall bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Ho; Koh, Young Hwan; Han, Dae Hee; Kim, Ji Hoon; Cha, Joo Hee; Lee, Eun Hye; Song, Chi Sung [Seoul National University Boramae Hospital, Seoul (Korea, Republic of)

    2008-05-15

    We describe our experience with the use of N-butyl cyanoacrylate (NBCA) embolization of abdominal wall bleeding and we evaluate the clinical effectiveness of the procedure. Embolization was performed in nine patients with abdominal wall bleeding. The sites of embolization were the left first lumbar (n = 1), left second lumbar (n = 1), right inferior epigastric (n 2), left inferior epigastric (n = 3), right circumflex iliac (n = 1), and left circumflex iliac artery (n = 1). A coil was used with NBCA in one patient due to difficulty in selecting only a bleeding focus and anticipated reflux. NBCA was mixed with Lipiodol at the ratio of 1:1 to 1:4. Blood pressure and heart rate were measured before and after the embolization procedure, and the serial hemoglobin and hematocrit levels and transfusion requirements were reviewed to evaluate hemostasis and rebleeding. Hemostasis was obtained in six out of the nine patients and technical success was achieved in all patients. There were no procedure-related complications. Four out of the nine patients died due to rebleeding of a subarachnoid hemorrhage (n = 1), multiorgan failure (n = 1), and hepatic failure (n =2) that occurred two to nine days after the embolization procedure. One patient had rebleeding. The five surviving patients had no rebleeding, and the patients continue to visit the clinical on an outpatient basis. NBCA embolization is a clinically safe procedure and is effective for abdominal wall bleeding.

  16. Degradation of n-butyl xanthate using fly ash as heterogeneous Fenton-like catalyst

    Institute of Scientific and Technical Information of China (English)

    陈绍华; 杜冬云

    2014-01-01

    Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investigated. The fly ash/H2O2 catalyst possesses a high oxidation activity for n-butyl xanthate degradation in aqueous solution. It is found that both the dosage of catalyst and initial solution pH significantly affect the n-butyl xanthate conversion efficient. The results indicate that by using 1.176 mmol/L H2O2 and 1.0 g/L fly ash catalyst with mass fraction of 4.14%Fe(III) oxide at pH 3.0, almost 96.90%n-butyl xanthate conversion and over 96.66%COD removal can be achieved within 120 min with heterogeneous catalysis by fly ash. CS2 as an intermediate of n-butyl xanthate oxidation. Finally, it is demonstrated that the fly ash/H2O2 catalytic oxidation process can be an efficient method for the treatment of n-butyl xanthate containing wastewater.

  17. N-butyl cyanoacrylate embolotherapy for acute gastroduodenal ulcer bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Ho; Kim, Ji Hoon; Koh, Young Hwan; Han, Dae Hee; Cha, Joo Hee; Seong, Chang Kyu; Song, Chi Sung [Seoul National University Boramae Hospital, Seoul (Korea, Republic of)

    2007-01-15

    Various embolic agents have been used for embolization of acute gastrointestinal (GI) arterial bleeding. N-butyl cyanoacrylate (NBCA) is not easy to handle, but it is a useful embolic agent. In this retrospective study, we describe our experience with NBCA embolization of acute gastroduodenal ulcer bleeding. NBCA embolization was performed in seven patients with acute upper GI arterial bleeding; they had five gastric ulcers and two duodenal ulcers. NBCA embolization was done in the left gastric artery (n = 3), right gastric artery (n = 2), gastroduodenal artery (n = 1) and pancreaticoduodenal artery (n = 1). Coil was used along with NBCA in a gastric bleeding patient because of difficulty in selecting a feeding artery. NBCA was mixed with Lipiodol at the ratio of 1:1 to 1:2. The blood pressure and heart rate around the time of embolization, the serial hemoglobin and hematocrit levels and the transfusion requirements were reviewed to evaluate hemostasis and rebleeding. Technical success was achieved in all the cases. Two procedure-related complications happened; embolism of the NBCA mixture to the common hepatic artery occurred in a case with embolization of the left gastric artery, and reflux of the NBCA mixture occurred into the adjacent gastric tissue, but these did not cause any clinical problems. Four of seven patients did not present with rebleeding, but two had rebleeding 10 and 16 days, respectively, after embolization and they died of cardiac arrest at 2 months and 37 days, respectively. One other patient died of sepsis and respiratory failure within 24 hours without rebleeding. NBCA embolization with or without other embolic agents could be safe and effective for treating acute gastroduodenal ulcer bleeding.

  18. Transcatheter Embolotherapy with N-Butyl Cyanoacrylate for Ectopic Varices

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Kim, Hyo-Cheol, E-mail: angiointervention@gmail.com; Jae, Hwan Jun, E-mail: jaemdphd@gmail.com; Jung, Hyun-Seok; Hur, Saebeom; Lee, Myungsu; Chung, Jin Wook [Seoul National University Hospital, Department of Radiology, Seoul National University College of Medicine (Korea, Republic of)

    2015-04-15

    PurposeTo address technical feasibility and clinical outcome of transcatheter embolotherapy with N-butyl cyanoacrylate (NBCA) for bleeding ectopic varices.MethodsThe institutional review board approved this retrospective study and waived informed consent. From January 2004 to June 2013, a total of 12 consecutive patients received transcatheter embolotherapy using NBCA for bleeding ectopic varices in our institute. Clinical and radiologic features of the endovascular procedures were comprehensively reviewed.ResultsPreprocedural computed tomography images revealed ectopic varices in the jejunum (n = 7), stoma (n = 2), rectum (n = 2), and duodenum (n = 1). The 12 procedures consisted of solitary embolotherapy (n = 8) and embolotherapy with portal decompression (main portal vein stenting in 3, transjugular intrahepatic portosystemic shunt in 1). With regard to vascular access, percutaneous transhepatic access (n = 7), transsplenic access (n = 4), and transjugular intrahepatic portosystemic shunt tract (n = 1) were used. There was no failure in either the embolotherapy or the vascular accesses (technical success rate, 100 %). Two patients died within 1 month from the procedure from preexisting fatal medical conditions. Only one patient, with a large varix that had been partially embolized by using coils and NBCA, underwent rebleeding 5.5 months after the procedure. The patient was retreated with NBCA and did not undergo any bleeding afterward for a follow-up period of 2.5 months. The remaining nine patients did not experience rebleeding during the follow-up periods (range 1.5–33.2 months).ConclusionTranscatheter embolotherapy using NBCA can be a useful option for bleeding ectopic varices.

  19. Chelation of heavy metals by potassium butyl dithiophosphate

    Institute of Scientific and Technical Information of China (English)

    Ying Xu; Zhigang Xie; Lu Xue

    2011-01-01

    Potassium butyl dithiophosphate (PBD) was developed and introduced as a new chelating agent for heavy metal removal.The synthesized PBD were characterized by IR and NMR.The effects of pH, chelating agent dosage, and other heavy metal ions on the performance of PBD in Cd2+ removal from water are investigated.Experimental results showed that the chelating agent could be used to treat acidic heavy metal wastewater.The Cd2+ removal was not affected by solution pH value within the range of 2 to 6.The Cd2+ removal rate could reach over 99%.Therefore, the deficiency of the precipitation process using hydroxide under alkaline condition can be overcome.Without the need for pH adjustment, the method could save on costs.If Cd2+ co-exists with Pb2+ and Cu2+, the affinity of the chelating agent with these three heavy metal ions was in the order of: Cu2+ > Pb2+ > Cd2+.Through PBD chelating precipitation,all the contents of Pb2+, Cd2+, and Cu2+ in wastewater met the standard levels through a one-step treatment.The one-step treatment process was superior to the process (sectional treatment is required) of precipitation with hydroxide.When the pH was between 3 and 11, the amount of leached chelated Cd2+ was much lower than that obtained by precipitation with hydroxide.Therefore, the risk of environmental pollution could be further reduced.

  20. The electrospinning of the copolymer of styrene and butyl acrylate for its application as oil absorbent.

    Science.gov (United States)

    Xu, Naiku; Cao, Jipeng; Lu, Yuyao

    2016-01-01

    Electrospun polystyrene materials have been employed as oil absorbents, but they have visible drawbacks such as poor strength at low temperature and unreliable integrity because of brittleness and insufficient cohesive force among fibers. Butyl acrylate can polymerize into flexible chains, and its polymer can be used as elastomer and adhesive material. Thereby it is possible to obtain the material that has better performance in comparison with electrospun polystyrene material through the electrospinning of the copolymer of styrene and butyl acrylate. In this work, a polymer was synthesized through suspension polymerization by using styrene and butyl acrylate as comonomers. The synthesis of the copolymer of styrene and butyl acrylate was verified through dissolution and hydrolysis experimental data; as well through nuclear magnetic resonance spectrometry. The viscous flow activation energy of the solution consisting of copolymer and N, N-dimethylformamide was determined via viscosity method and then adopted to establish the entanglement characteristics of butyl acrylate's chain segments. Finally, in order to electrospin the copolymer solution into fibrous membrane, the effects of monomer feed ratio and spinning parameters were investigated. The prepared fibrous membrane was found to have a potential use as oil absorbent.

  1. Alkylation of Catechol with tert-Butyl Alcohol Catalyzed by Mesoporous Acidic Montmorillonite Heterostructure Catalysts

    Institute of Scientific and Technical Information of China (English)

    周春晖; 葛忠华; 李小年; 童东绅; 李庆伟; 郭红强

    2004-01-01

    The liquid phase alkylation of catechol with tert-butyl alcohol to produce 4-tert-butyl catechol (4-TBC) was carried out over MCM-41, HZSM-5, H-exchanged montmorillonite and novel acidic porous montmorillonite heterostructures (PMHs). Upon all catalysts tested, 4-TBC is the main product and 3-tert-butyl catechol (3-TBC) and 3,5-di-tert-butyl catechol are the side products. The synthetic PMHs showed higher conversion of catechol and better selectivity to 4-TBC compared to other solid acid catalysts tested. Over the PMHs derived from H-exchanged montmorillonite through template extraction processes, the suitable reaction temperature is ca 410 K, the ratio of catechol to tert-butyl alcohol is 1:2. Increasing the amount of catalyst (lower weight hourly space velocity) can improve the conversion of catechol and influence the selectivity slightly. The reasonable reaction time is ca 8 h.The type and strength of acidity of H-montmorillonite and PMH were determined by pyridine adsorption FT-IR and ammonia temperature-programmed desorption techniques. The medium and strong acid sites are conducive to producing 4-TBC and the weak acid sites to facilitating the 3-TBC formation. The differences between the PMHs from calcination and those fi'om extraction are attributed to proton migration and acidity change in the gallery surface.

  2. Thermal decomposition mechanism of p-tert-butyl-calix[n]arenes

    Energy Technology Data Exchange (ETDEWEB)

    Chennakesavulu, K., E-mail: chennanml@yahoo.com [National Metallurgical Laboratory Madras Centre, CSIR Madras Complex, Taramani, Chennai 600 113 (India); Department of Chemistry, Sathyabama University, Jeppiaar Nagar, Chennai 600 119 (India); Sreedevi, P.; Raviathul Basaria, M. [National Metallurgical Laboratory Madras Centre, CSIR Madras Complex, Taramani, Chennai 600 113 (India); Ramanjaneya Reddy, G. [Department of Inorganic Chemistry, Guindy Campus, University of Madras, Chennai 600 025 (India); Sasipraba, T. [International Research Centre, Sathyabama University, Jeppiaar Nagar, Chennai 600 119 (India); Bhaskar Raju, G.; Prabhakar, S. [National Metallurgical Laboratory Madras Centre, CSIR Madras Complex, Taramani, Chennai 600 113 (India)

    2014-01-10

    Highlights: • Systematic thermal decomposition, structural elucidation of intermediates at various quenched temperatures. • At solid state the phenolic free radical was quenched and was evidenced by recording stable EPR. • Since the lower decomposition energy these p-tert-butyl-calix[n]arenes can be used as a antioxidants for thermal stabilization of polyolefins. • Solid state NMR CP-MAS studies show the breakage of calixarene at bridged methylene. • Kinetic triplets of p-tert-butyl-calixarenes were determined by model free methods. - Abstract: Thermal decomposition of p-tert-butyl-calix[n]arene was studied using thermo gravimetry (TG) and differential thermo gram (DTG) methods. Non-isothermal TG was done under static air atmosphere with 1, 2.5, 5.0 and 10.0 K/min. Model-free methods such as Friedman and Flynn Wall Ozawa (FWO) were used to evaluate the kinetic parameters such as activation energy and exponential factors. The probable thermal decomposition mechanism was proposed by analyzing the quenched intermediate p-tert-butyl-calix[n]arene samples with FTIR, mass, {sup 1}H NMR, {sup 13}C NMR cross polarization magic angle spectrometry (CP-MAS), EPR spectroscopy and elemental analysis. The thermal stability of the polyolefins was checked with p-tert-butyl-calix[n]arene as an antioxidant additive.

  3. Hydrogen bonded rings, chains and lassos: the case of t-butyl alcohol clusters

    Science.gov (United States)

    Zimmermann, D.; Häber, Th.; Schaal, H.; Suhm, M. A.

    Infrared OH stretching spectra of hydrogen bonded 2-methyl-propan-2-ol (t-butyl alcohol) clusters are investigated by ragout-jet FTIR spectroscopy. A spectral difference technique is used to discriminate approximately between neighbouring cluster sizes. Dimers, trimers and cyclic tetramers can be detected along with larger clusters, which exhibit a surprisingly structured vibrational fingerprint. Comparison is made to the spectra of related alcohols and to energetic and harmonic vibrational predictions from electronic structure calculations. The experimentally observed 32% increase in OH stretching wavenumber shift from methanol dimer to t-butyl alcohol dimer is reproduced at the HF/3-21G level (+ 33%). It is also qualitatively correct at the MP2/6-31+ G* level (+ 15%), whereas it has the wrong sign at the B3LYP/6-31+ G* level (-5%) and is negligible at the HF/6-31+ G* level, disregarding anharmonic effects. The cyclic tetramer of t-butyl alcohol is found to be particularly stable due to a favourable up-down alternation of the bulky t-butyl groups. Beyond the t-butyl alcohol tetramer, lasso structures are found to be energetically competitive with simple ring structures. A many-body decomposition shows that this is due to a reduced cooperativity in the sterically hindered pentamer ring. The resulting thermodynamic and kinetic relevance of cyclic tetramers is discussed.

  4. Human gallbladder morphology after gallstone dissolution with methyl tert-butyl ether.

    Science.gov (United States)

    vanSonnenberg, E; Zakko, S; Hofmann, A F; D'Agostino, H B; Jinich, H; Hoyt, D B; Miyai, K; Ramsby, G; Moossa, A R

    1991-06-01

    The effects of methyl tert-butyl ether exposure on the human gallbladder in five patients who were treated for gallstones by contact dissolution is described. Two patients underwent cholecystectomy within 1 week of methyl tert-butyl ether treatment, one patient 2 weeks after, another 10 weeks after, and one 12 weeks after. Indications for cholecystectomy were bilirubinate stones (resistant to methyl tert-butyl ether), catheter dislodgement, bile leakage, and gallstone recurrence (2 patients). Gallstones were dissolved completely in three patients, there was approximately 50% stone reduction in one patient, and no dissolution occurred in the fifth patient. Each gallbladder was examined grossly and histologically. Electron microscopic evaluation was performed in one cases. Typical inflammatory findings of chronic cholecystitis were observed in each gallbladder and were most conspicuous in the submucosa; the mucosal and serosal surfaces were intact. Mild acute inflammatory changes were noted in the submucosa in the two patients with the shortest interval between methyl tert-butyl ether administration and cholecystectomy. There were no ulcerations in the mucosa and no unusual wall thickening or fibrosis in any patient. These observations support the safety of methyl tert-butyl ether perfusion in the human gallbladder; the mild acute changes may be a transient and reversible phenomenon.

  5. Production of butyl-biodiesel using lipase physically-adsorbed onto electrospun polyacrylonitrile fibers.

    Science.gov (United States)

    Sakai, Shinji; Liu, Yuping; Yamaguchi, Tetsu; Watanabe, Rie; Kawabe, Masaaki; Kawakami, Koei

    2010-10-01

    Butyl-biodiesel production using electrospun polyacrylonitrile fibers with Pseudomonas cepacia lipase immobilized through physical adsorption was studied. About 80% conversion to butyl-biodiesel was achieved after 24h by suspending the catalyst at 2.4 mg/mL in a mixture of rapeseed oil and n-butanol at a molar ratio of 1:3, containing water at 8000 ppm at 40 degrees C. A further 24h of operation resulted in 94% conversion. The initial reaction rate detected for this process was 65-fold faster than those detected for Novozym 435 on a total catalyst mass basis. The immobilized lipase continued to work as a catalyst for 27 d, within a 15% reduction in conversion yield at the outlet of the reactor compared with the average value detected during the first 3d of operation in a continuous butyl-biodiesel production system.

  6. Spectroscopic analysis of 1-butyl-2,3-dimethylimidazolium ionic liquids: Cation-anion interactions

    Science.gov (United States)

    Men, Shuang; Jiang, Jing; Licence, Peter

    2017-04-01

    In this study, four 1-butyl-2,3-dimethylimidazolium ionic liquids are analysed by X-ray photoelectron spectroscopy, together with three 1-butyl-3-methylimidazolium ionic liquids. A reliable fitting model for the carbon 1s region of 1-butyl-2,3-dimethylimidazolium ionic liquids is modified according to established models. The effect of the anion on the electronic environment of the cation is explored based upon the comparison between measured binding energies of nitrogen 1s and the hydrogen bond acceptor ability. The effect of the cation on the cation-anion interaction is also demonstrated by carefully comparing the hydrogen bond donating ability of different cations, with a definite anion.

  7. Molecular recognition study of ethosuximide by the supramolecular probe, p-t-butyl calix(8)arene

    Energy Technology Data Exchange (ETDEWEB)

    Meenakshi, C., E-mail: geethu.laxi@gmail.com [Department of Chemistry, Shri Meenakshi Government College for Women (Autonomous), Madurai 625002 (India); Sangeetha, P.; Ramakrishnan, V. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai 625021 (India)

    2013-06-15

    The supramolecule, p-t-Butyl calix(8)arene, forms inclusion complex with the antiseizure drug molecule, ethosuximide. This feature is explained on the basis of optical absorption spectroscopy. Here p-t-Butyl calix(8)arene is the host molecule and ethosuximide is the guest molecule. The stoichiometry of the host–guest complex and the binding constant has been determined using Benesi–Hildebrand plot. Based on the result obtained the structure of the inclusion complex has been proposed. -- Highlights: ► Third generation supramolecule, t-butyl calix (8) arene, is used as a host molecule. ► Anti seizure drug molecule is used as a guest molecule. ► Inclusion complex is formed between the host and guest molecule.

  8. The 4-methylthio-1-butyl group for phosphate/thiophosphate protection in oligodeoxyribonucleotide synthesis.

    Science.gov (United States)

    Cieślak, Jacek; Grajkowski, Andrzej; Livengood, Victor; Beaucage, Serge L

    2004-12-01

    The detailed preparation of deoxyribonucleoside phosphoramidites functionalized with a 4-methylthio-1-butyl group for P(III) protection is described, along with the incorporation of these phosphoramidites into DNA oligonucleotides via solid-phase techniques. The versatility of the thermolabile 4-methylthio-1-butyl phosphate/thiophosphate-protecting group is exemplified through its facile removal from oligonucleotides under neutral conditions or under standard basic conditions. The sulfonium salt that is produced during the thermolytic deprotection of oligonucleotides did not alter DNA nucleobases or desulfurize phosphorothioate diesters to a significant extent.

  9. Percutaneous N-Butyl cyanoacrylate embolization of a pancreatic pseudoaneurysm after failed attempts of transcatheter embolization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ri Hyeon; Yoo, Roh Eul; Kim, Hyo Cheol [Seoul National University Medical Research Center, and Clinical Research Institute, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-10-15

    One common complication after major pancreatic surgery is bleeding. Herein we describe a case of pancreatic pseudoaneurysm which developed after pylorous preserving pancreaticoduodenectomy for common bile duct cancer. Three attempts of transcatheter embolization failed since feeders to the pseudoaneurysm had unfavorable anatomy. Direct percutaneous N-butyl cyanoacrylate injection was performed under fluoroscopy-guidance and the pseudoaneurysm was successfully treated. Percutaneous fluoroscopy-guided direct N-butyl cyanoacrylate injection may be a useful alternative when selective transcatheter embolization fails or is technically challenging.

  10. Influence of Temperature on Thermodynamic Properties of Methyl t-Butyl Ether (MTBE) + Gasoline Additives

    Science.gov (United States)

    Gonzalez-Olmos, R.; Iglesias, M.; Goenaga, J. M.; Resa, J. M.

    2007-08-01

    The densities and sound speeds of binary mixtures of methyl tert-butyl ether (MTBE) + (benzene, toluene, ethylbenzene, isooctane, tert-butyl alcohol) have been measured at temperatures from 288.15 to 323.15 K and at atmospheric pressure over the complete concentration range. The experimental excess volumes and deviations of isentropic compressibility were calculated. The deviation of isentropic compressibility data have been analyzed in terms of different theoretical models; adequate agreement between the experimental and predicted values is obtained. The data from this study improve the data situation related to gasoline additives and help to understand the MTBE volumetric and acoustic behavior for various chemical systems.

  11. Pressure-induced phase transition of 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6

    Science.gov (United States)

    Takekiyo, Takahiro; Hatano, Naohiro; Imai, Yusuke; Abe, Hiroshi; Yoshimura, Yukihiro

    2011-03-01

    We have investigated the pressure-induced Raman spectral change of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) using Raman spectroscopy. The relative Raman intensity at 590 cm-1 of the CH2 rocking band assigned to the gauche conformer of the NCCC dihedral angle of the butyl group in the [bmim]+ cation increases when the pressure-induced liquid-crystalline phase transition occurs, while that at 610 cm-1 assigned to the trans conformer decreases. Our results show that the high-pressure phase transition of [bmim][PF6] causes the increase of the gauche conformer of the [bmim]+ cation.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    The fraction of biologically active methyl tert-butyl ether degraders in reactors is just as important for prediction of removal rates as knowledge of the kinetic parameters. The fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample, taken from a packed...

  13. An alternative approach to synthesis of 2--butyl-5-nitrobenzofuran derivative: A key starting material for dronedarone hydrochloride

    Indian Academy of Sciences (India)

    P Raja Gopal; E R R Chandrashekar; M Saravanan; B Vijaya Bhaskar; P Veera Somaiah

    2012-09-01

    A practical synthesis of (2-butyl-5-nitrobenzofuran-3-yl)(4-hydroxyphenyl)methanone, a key intermediate in the preparation of anti arrhythmic drug, is described. The commercially available 4-nitrophenol (3) is converted in five steps to 2-butyl-5-nitrobenzofuran (9) which upon Friedel-Crafts acylation with 4-methoxybenzoyl chloride followed by deprotection of methyl group gives (2).

  14. Biodegradation of ethyl t-butyl ether (ETBE), methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) by Gordonia terrae.

    Science.gov (United States)

    Hernandez-Perez, G; Fayolle, F; Vandecasteele, J P

    2001-01-01

    Gordonia terrae strain IFP 2001 was selected from activated sludge for its capacity to grow on ethyl t-butyl ether (ETBE) as sole carbon and energy source. ETBE was stoichiometrically degraded to t-butyl alcohol (TBA) and the activity was inducible. A constitutive strain, G. terrae IFP 2007, derived from strain IFP 2001, was also selected. Methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) were not used as carbon and energy sources by the two strains, but cometabolic degradation of MTBE and TAME was demonstrated, to TBA and t-amyl alcohol (TAA) respectively, in the presence of a carbon source such as ethanol. No two-carbon compound was detected during growth on ETBE, but formate was produced during cometabolic degradation of MTBE or TAME. A monooxygenase was involved in the degradation of ethers, because no degradation of ETBE was observed under anaerobic conditions and the presence of a cytochrome P-450 was demonstrated in G. terrae IFP 2001 after induction by cultivation on ETBE.

  15. PHOTOCATALYTIC OXIDATION OF METHYL-TERT-BUTYL ETHER FOR DRINKING WATER TREATMENT

    Science.gov (United States)

    The photo-oxidation of methyl tert-butyl ether (MTBE) in water was investigated to determine the feasibility of using photocatalysis for the treatment of MTBE-contaminated drinking water. The feasibility assessment was conducted using slurries of titanium dioxide in both a photo-...

  16. A new efficient synthesis of isothiocyanates from amines using di-tert-butyl dicarbonate

    DEFF Research Database (Denmark)

    Munch, Henrik; Hansen, Jon S.; Pittelkow, Michael;

    2008-01-01

    Alkyl and aryl amines are converted smoothly to the corresponding isothiocyanates via the dithiocarbamates in good to excellent yields using di-tert-butyl dicarbonate (Boc(2)O) and 1-3 mol% of DMAP or DABCO as catalyst. As most of the byproducts are volatile, the work-up involves simple evaporation...

  17. (R-N-{2-tert-Butyl-2-[(R-tert-butylsulfonamido]ethylidene}-tert-butanesulfonamide

    Directory of Open Access Journals (Sweden)

    Cong-Bin Fan

    2008-10-01

    Full Text Available The title compound, C14H30N2O2S2, is the product of the monoaddition reaction of tert-butyl magnesium chloride with bis-[(R-N-tert-butanesulfinyl]ethanediimine. There are two almost identical molecules in the asymmetric unit, the molecular conformation of which is stabilized by an intramolecular N—H...N hydrogen bond.

  18. Optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation☆

    Institute of Scientific and Technical Information of China (English)

    Hui Tian; Suying Zhao; Huidong Zheng; Zhixian Huang

    2015-01-01

    Based on a previous investigation, a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distil ation. An experimental setup was established to verify the simulated results. The effects of various operating variables, such as ethanol feed location, acetic acid feed location, feed stage of reaction mixture of acetic acid and n-butanol, reflux ratio of ethyl acetate reactive distillation column, and distil-late to feed ratio of n-butyl acetate column, on the ethanol/n-butanol conversions, ethyl acetate/n-butyl acetate purity, and energy consumption were investigated. The optimal results in the simulation study are as follows:ethanol feed location, 15th stage;acetic acid feed location, eighth stage;feed location of reaction mixture of acetic acid and n-butanol, eighth stage;reflux ratio of ethyl acetate reactive distillation column, 2.0;and distillate to feed ratio of n-butyl acetate, 0.6.

  19. Energetic Materials Center Report--Small-Scale Safety and Thermal Testing Evaluation of Butyl Nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center

    2013-04-26

    Butyl Nitrate (BN) was examined by Small-Scale Safety and Thermal (SSST) Testing techniques to determine its sensitivity to impact, friction, spark and thermal exposure simulating handling and storage conditions. Under the conditions tested, the BN exhibits thermal sensitivity above 150 °C, and does not exhibit sensitive to impact, friction or spark.

  20. Preparation of L-Butyl Lactate via Transesterification by Using Nafion-H Catalyst

    Institute of Scientific and Technical Information of China (English)

    Wei LI; Guo Rong ZHENG; Ping LU

    2005-01-01

    Optically pure L-butyl lactate was synthesized by normal transesterification using nafion-H catalyst in moderate yield. Various reaction conditions were investigated, including the reaction temperature, reaction time, ratio of the starting material and amount of the nafion catalyst.

  1. Irradiation Initiated Grafting of Poly(butyl acrylate) onto Nano-sized Calcium Carbonate Particles

    Institute of Scientific and Technical Information of China (English)

    Chuan Guo MA; Min Zhi RONG; Ming Qiu ZHANG

    2005-01-01

    The present work reports the irradiation induced grafting polymerization onto nano-sized CaCO3 particles, mainly focusing on the effects of pretreatment with silane coupling agent. It is proved that poly(butyl acrylate) can be grafted onto the nanoparticles using the technical route suggested by the authors, and the silane treatment of the nanoparticles promotes the grafting polymerization.

  2. Tri(t-butyl)phosphine-assisted selective hydrosilylation of terminal alkynes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A highly efficient and regio-/stereoselective method of hydrosilylating terminal alkynes was developed using Pt(DVDS)-tri(t-butyl) phosphine catalyst system at room temperature.Trans-products or alpha-products were obtained almost exclusively depending on the alkynes and silanes employed.

  3. 77 FR 27164 - Butylate, Clethodim, Dichlorvos, Dicofol, Isopropyl Carbanilate, et al.; Proposed Tolerance Actions

    Science.gov (United States)

    2012-05-09

    ... the nomenclature of specific tolerances for butylate, methomyl, and tralomethrin, and remove expired... permitted by the tolerance. In addition, EPA is proposing to revise the nomenclature of specific tolerances... May 17, 2011, cease all sales and distribution of dicofol end-use products by October 31, 2013,...

  4. A direct and sustainable synthesis of tertiary butyl esters enabled by flow microreactors.

    Science.gov (United States)

    Degennaro, Leonardo; Maggiulli, Daniela; Carlucci, Claudia; Fanelli, Flavio; Romanazzi, Giuseppe; Luisi, Renzo

    2016-08-01

    Tertiary butyl esters find large applications in synthetic organic chemistry. A straightforward method for the direct introduction of the tert-butoxycarbonyl group into a variety of organic compounds has been developed using flow microreactor systems. The resultant flow process was more efficient, versatile and sustainable compared to the batch.

  5. A new steroidal compound (β-sitosterol-3-O-butyl isolated from Caesalpinia gilliesii flowers

    Directory of Open Access Journals (Sweden)

    Samir Mohamed Osman

    2015-01-01

    Full Text Available Summary. The study aimed to evaluate the cytotoxic activity of total extracts from leaves, flowers and pods of Caesalpinia gilliesii (Fabaceae, Caesalpinoideae. In addition, a detailed phytochemical investigation of flower extracts was carried out to isolate and elucidate the structures of the bioactive compounds. Flower extract was the most cytotoxic against MCF7 and HepG2 cancer cells with IC50 values of 10 and 15.6 µg/mL, respectively. A new β-sitosterol-3-O-butyl was isolated from dichloromethane fraction of flowers together with another known sterol (daucosterol, and two flavonoids (isorhamnetin and isorhamnetin 3-O-rhamnoside. β-sitosterol-3-O-butyl was the most active compound against both HepG2 and MCF7 cells with IC50 values of 13.1 and 14.4 µg/mL, respectively. Isorhamnetin possesses a moderate antioxidant activity with an IC50 value 370 µg/mL as determined by DPPH radical scavenging assay.Industrial relevance. β-sitosterol-3-O-butyl and the other phytosterols are responsible for the cytotoxicity of the extracts which would correlate with the known abortifacient, antimalarial and anthelmintic properties, which can provide a cheap alternative drug.Keywords. Cytotoxicity, antioxidant; Caesalpinia gilliesii; β-sitosterol-3-O-butyl; daucosterol; isorhamnetin-3-O-rhamnoside

  6. Kinetic Study of the Reaction between Tert-butyl Hydrazine and Nitrous Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The kinetic study of the reaction between tert-butyl hydrazine(TBH)and nitrous acid in nitric acid system is performed by spectrophotometry. The effect of some factors such as the concentration of TBH, the concentration of nitric acid, ionic strength, temperature and the

  7. A Chiral Macroscopic Force between Liquid of Butyl Alcohol and Copper Block

    Institute of Scientific and Technical Information of China (English)

    HU Yong-Hong; LIU Zhong-Zhu

    2008-01-01

    A non-zero macroscopic chirality-dependent force between a copper block and a vessel of homochiral molecules(butyl alcohol) is calculated quantitatively with the central field approximation. The magnitude of the force is estimated with the published limits of the scalar and pseudo-scalar coupling constants.

  8. A Case of Successful Ablation of a Gastrophrenic Fistula with n-Butyl-2-Cyanoacrylate

    Directory of Open Access Journals (Sweden)

    Ashish Mahajan

    2008-01-01

    Full Text Available A 79-year-old woman with a fistula between a subphrenic abscess and the fundus of the stomach was successfully treated with n-Butyl-2-Cyanoacrylate. Conservative management had failed. Clinical presentation, treatment progress and imaging findings by computed tomography scan, ultrasound, gastroscopy and fluoroscopy are presented, along with a brief review of the relevant literature.

  9. Enhanced diisobutene production in the presence of methyl tertiary butyl ether

    Science.gov (United States)

    Smith, L.A. Jr.

    1983-03-01

    In the liquid phase reaction of isobutene in the presence of resin cation exchange resins with itself in a C[sub 4] hydrocarbon stream to form dimers, the formation of higher polymers, oligomers, and co-dimer by-products is suppressed by the presence of 0.0001 to 1 mole per mole of isobutene of methyl tertiary butyl ether. 1 fig.

  10. Synthesis and characterization of birch wood xylan succinoylated in 1-n-butyl-3-methylimidazolium chloride

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Plackett, David

    2011-01-01

    The chemical modification of birch wood xylan was undertaken in the ionic liquid 1-n-butyl-3-methylimidazolium chloride (C4mimCl) using three different long-chain succinic anhydrides: n-octenyl succinic anhydride (n-OSA), n-dodecenyl succinic anhydride (n-DDSA) and n-octadecenyl succinic anhydrid...

  11. TREATMENT OF METHYL TERT-BUTYL ETHER CONTAMINATED WATER USING PHOTOCATALYSIS

    Science.gov (United States)

    The feasibility of photo-oxidation treatment of methyl tert-butyl ether (MTBE) in water was investigated in three ways, 1) using a slurry falling film photo-reactor, 2) a batch solar reactor system, and 3) a combination of air-stripping and gas phase photooxidation system. MTBE-c...

  12. Polypyrrole-coated styrene-butyl acrylate copolymer composite particles with tunable conductivity

    Institute of Scientific and Technical Information of China (English)

    HUANG Liyan; HOU Wenbo; LIU Zhengping; ZHANG Qingyue

    2005-01-01

    A series of near or monodisperse styrene-butyl acrylate (SBA) copolymer latex particles with different butyl acrylate contents were coated with polypyrrole. The structure of the SBA/PPy composites was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC) and standard four-probe method. The core-shell morphology of the SBA/PPy composite particles was confirmed. The result of DSC showed that Tg of the composite is mainly determined by the core component. The effects of the concentration of polypyrrole, the butyl acrylate content in SBA copolymer and the nature of the counter-anion on the electrical conductivity of compression-moulded samples were studied. It was first found that the electrical conductivity of the samples can be tuned by varying the butyl acrylate content in SBA copolymer and the highest conductivity of the core-shell composite was 0.17 S·cm-1.

  13. IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (Etbe) (Interagency Science Consultation Draft)

    Science.gov (United States)

    In September 2016, EPA released the draft IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) for public comment and discussion. The draft assessment was reviewed internally by EPA and by other federal agencies and White House Offices before public release. Consistent ...

  14. IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (Etbe) (Public Comment Draft)

    Science.gov (United States)

    In September 2016, the U.S. Environmental Protection Agency's (USEPA) released the draft Integrated Risk Information System (IRIS) Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE). Consistent with the 2013 IRIS Enhancements, draft IRIS assessments are released prior to e...

  15. IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (Etbe) (External Review Draft, 2009)

    Science.gov (United States)

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of ethyl tertiary butyl ether (ETBE) that when finalized will appear on the Integrated Risk Information System (IRIS) database.

  16. Morphology and film formation of poly(butyl methacrylate)-polypyrrole core-shell latex particles

    NARCIS (Netherlands)

    Huijs, F; Lang, J

    2000-01-01

    Core-shell latex particles made of a poly(butyl methacrylate) (PBMA) core and a thin polypyrrole (PPy) shell were synthesized by two-stage polymerization. In the first stage, PBMA latex particles were synthesized in a semicontinuous process by free-radical polymerization. PBMA latex particles were l

  17. Liquid/air partition coefficients of methyl and ethyl T-butyl ethers, T-amyl methyl ether, and T-butyl alcohol.

    Science.gov (United States)

    Nihlen, A; Lof, A; Johanson, G

    1995-01-01

    Partition coefficients are essential to a description of the uptake and distribution of volatile substances in humans and in the development of physiologically based pharmacokinetic models. Liquid/air partition coefficients (lambda) of three ethers, methyl t-butyl ether (MTBE), ethyl t-butyl ether (ETBE), and t-amyl methyl ether (TAME) were determined in vitro by head space-gas chromatography. These ethers, and especially MTBE, are used in unleaded gasoline to enhance the oxygen and octane content, and to reduce the output of carbon monoxide during combustion. Partition coefficients of t-butyl alcohol (TBA), a metabolite of MTBE, were determined also. The liquids tested were fresh human blood, water (physiological saline), and olive oil. The (lambda)blood/air values were: 17.7 (95% confidence interval 17.0-18.4) for MTBE; 11.7 (11.3-12.1) for ETBE; and 17.9 (17.3-18.5) for TAME. Corresponding (lambda)water/air values were 15.2 (14.9-15.5), 8.39 (8.19-8.59), and 11.9 (11.7-12.1). The ethers have a higher affinity for oil, the values for (lambda)oil/air being 120 (114-125), 190 (183-197), and 337 (320-354), respectively. As expected, the (lambda)blood/air and (lambda)water/air for TBA were much higher than for the ethers, 462 (440-484) and 603 (590-617), respectively. The (lambda)oil/air was 168 (161-174) for TBA. The interindividual variability of the (lambda)blood/air (10 subjects) was calculated as the coefficient of variation, and estimated as: 14% for MTBE, 20% for ETBE, 20% for TAME, and 30% for TBA. No significant difference was seen in the (lambda)blood/air between the sexes.

  18. Biodegradation of the gasoline oxygenates methyl tert-butyl ether, ethyl tert-butyl ether, and tert-amyl methyl ether by propane-oxidizing bacteria.

    Science.gov (United States)

    Steffan, R J; McClay, K; Vainberg, S; Condee, C W; Zhang, D

    1997-11-01

    Several propane-oxidizing bacteria were tested for their ability to degrade gasoline oxygenates, including methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). Both a laboratory strain and natural isolates were able to degrade each compound after growth on propane. When propane-grown strain ENV425 was incubated with 20 mg of uniformly labeled [14C]MTBE per liter, the strain converted > 60% of the added MTBE to 14CO2 in production of nearly stoichiometric amounts of tert-butyl alcohol (TBA), while the initial oxidation of TAME resulted in the production of tert-amyl alcohol. The methoxy methyl group of MTBE was oxidized to formaldehyde and ultimately to CO2. TBA was further oxidized to 2-methyl-2-hydroxy-1-propanol and then 2-hydroxy isobutyric acid; however, neither of these degradation products was an effective growth substrate for the propane oxidizers. Analysis of cell extracts of ENV425 and experiments with enzyme inhibitors implicated a soluble P-450 enzyme in the oxidation of both MTBE and TBA. MTBE was oxidized to TBA by camphor-grown Pseudomonas putida CAM, which produces the well-characterized P-450cam, but not by Rhodococcus rhodochrous 116, which produces two P-450 enzymes. Rates of MTBE degradation by propane-oxidizing strains ranged from 3.9 to 9.2 nmol/min/mg of cell protein at 28 degrees C, whereas TBA was oxidized at a rate of only 1.8 to 2.4 nmol/min/mg of cell protein at the same temperature.

  19. Synthesis, Resolution, and Enantiomeric Purity Assay of 2-n-Butylbutanedioic Acid 4-t-Butyl Esters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The (R)-and (S)-2-n-butylbutanedioic acid 4-t-butyl esters were obtained by the resolution of the above-mentioned racemic compounds with(S)-( - ) or(R)-( + )-α-methylbenzylamine, respectively. The e.e. values of the two optical active products were determined to be above 99% by HPLC after the formation of two pairs of diastereoisomers with ( R)-( + )-α-methylbenzylamine and (S)-phenylalanine methyl ester.

  20. Solid-phase synthesis of thermolytic DNA oligonucleotides functionalized with a single 4-hydroxy-1-butyl or 4-phosphato-/thiophosphato-1-butyl thiophosphate protecting group.

    Science.gov (United States)

    Grajkowski, Andrzej; Ausín, Cristina; Kauffman, Jon S; Snyder, John; Hess, Sonja; Lloyd, John R; Beaucage, Serge L

    2007-02-02

    Several thermolytic CpG-containing DNA oligonucleotides analogous to 1 have been synthesized to serve as potential immunotherapeutic oligonucleotide prodrug formulations for the treatment of infectious diseases in animal models. Specifically, the CpG motif (GACGTT) of each DNA oligonucleotide has been functionalized with either the thermolabile 4-hydroxy-1-butyl or the 4-phosphato-/thiophosphato-1-butyl thiophosphate protecting group. This functionalization was achieved through incorporation of activated deoxyribonucleoside phosphoramidite 8b into the oligonucleotide chain during solid-phase synthesis and, optionally, through subsequent phosphorylation effected by phosphoramidite 9. Complete conversion of CpG ODNs hbu1555, psb1555, and pob1555 to CpG ODN 1555 (homologous to 2) occurred under elevated temperature conditions, thereby validating the function of these diastereomeric oligonucleotides as prodrugs in vitro. Noteworthy is the significant increase in solubility of CpG ODN psb1555 and CpG pob1555 in water when compared to that of neutral CpG ODN fma1555 (homologous to 1).

  1. No Promoting Effect of Ethyl Tertiary-butyl Ether (ETBE) on Rat Urinary Bladder Carcinogenesis Initiated with N-Butyl-N-(4-hydroxybutyl)nitrosamine.

    Science.gov (United States)

    Hagiwara, Akihiro; Imai, Norio; Doi, Yuko; Suguro, Mayuko; Kawabe, Mayumi; Furukawa, Fumio; Nagano, Kasuke; Fukushima, Shoji

    2013-12-01

    The effects of ethyl tertiary-butyl ether (ETBE) on two-stage urinary bladder carcinogenesis in male F344 rats initiated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) were investigated at various dose levels with regard to possible promoting activity. Groups of 30 rats were given drinking water containing 500 ppm BBN, as an initiator, for 4 weeks and starting one week thereafter received ETBE by gavage (daily, 7 days/week) at dose levels of 0 (control), 100, 300, 500 or 1000 mg/kg/day until experimental week 36. No statistically significant differences in incidences of preneoplastic lesions, papillomas, and carcinomas of the urinary bladder were evident in rats treated with 100-1000 mg/kg/day ETBE as compared with control values. Furthermore, the average numbers of preneoplastic or neoplastic lesions per unit length of basement membrane in rats given 100-1000 mg/kg/day ETBE were also comparable to control values. However, papillomatosis of the urinary bladder was found in 4 out of 30 rats (13%) in the group given 1000 mg/kg/day ETBE, and soft stones in the urinary bladder were found in 3 out of these 4 rats. The results thus demonstrated that ETBE did not exert promotional activity on urinary bladder carcinogenesis. However, papillomatosis of the urinary bladder developed in small numbers of the rats given ETBE at 1000 mg/kg/day but not in rats given 500 mg/kg/day or lower doses.

  2. Selection and identification of bacterial strains with methyl-tert-butyl ether, ethyl-tert-butyl ether, and tert-amyl methyl ether degrading capacities.

    Science.gov (United States)

    Purswani, Jessica; Pozo, Clementina; Rodríguez-Díaz, Marina; González-López, Jesús

    2008-11-01

    Nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/L of one of the following gasoline oxygenates: Methyl-tert-butyl ether (MTBE), ethyl-tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). These strains were identified by amplification of their 16S rRNA gene, using fDl and rD1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and cometabolic media. The isolates were classified as Bacillus simplex, Bacillus drentensis, Arthrobacter sp., Acinetobacter calcoaceticus, Acinetobacter sp., Gordonia amicalis (two strains), Nocardioides sp., and Rhodococcus ruber. Arthrobacter sp. (strain MG) and A. calcoaceticus (strain M10) consumed 100 (cometabolic medium) and 82 mg/L (mineral medium) of oxygenate TAME in 21 d, respectively, under aerobic conditions. Rhodococcus ruber (strain E10) was observed to use MTBE and ETBE as the sole carbon and energy source, whereas G. amicalis (strain T3) used TAME as the sole carbon and energy source for growth. All the bacterial strains transformed oxygenates better in the presence of an alternative carbon source (ethanol) with the exception of A. calcoaceticus (strain M10). The capacity of the selected strains to remove MTBE, ETBE, and TAME looks promising for application in bioremediation technologies.

  3. Separation of the Ternary System of Methanol/Methyl Butyl Ether/1-Butylchloride

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The separation of ternary methanol/methyl butyl ether/1-butylchloride mixtures was investigated, which are the main components of the waste liquid. After preliminary studies on the ternary system, the integrated process of extraction and distillation was put forward to separate the ternary system. The results show that methanol can be removed from the mixtures by extraction using water as the extracting agent. Through distillation of extract and dried raffinate respectively, methanol,methyl butyl ether and 1-butylchloride can be separated and recovered. In addition, the optimal volume for the extracting agent and effects of reflux ratio on the yield of product were also studied. The optimal volume ratio of the extracting agent to material is 1: 3.5, and the yield of the product increases with the increase of reflux ratio.

  4. Collagen-Immobilized Lipases Show Good Activity and Reusability for Butyl Butyrate Synthesis.

    Science.gov (United States)

    Dewei, Song; Min, Chen; Haiming, Cheng

    2016-11-01

    Candida rugosa lipases were immobilized onto collagen fibers through glutaraldehyde cross-linking method. The immobilization process has been optimized. Under the optimal immobilization conditions, the activity of the collagen-immobilized lipase reached 340 U/g. The activity was recovered of 28.3 % by immobilization. The operational stability of the obtained collagen-immobilized lipase for hydrolysis of olive oil emulsion was determined. The collagen-immobilized lipase showed good tolerance to temperature and pH variations in comparison to free lipase. The collagen-immobilized lipase was also applied as biocatalyst for synthesis of butyl butyrate from butyric acid and 1-butanol in n-hexane. The conversion yield was 94 % at the optimal conditions. Of its initial activity, 64 % was retained after 5 cycles for synthesizing butyl butyrate in n-hexane.

  5. Di-n-butylbis(N-n-butyl-N-ethyldithiocarbamato-κStin(IV

    Directory of Open Access Journals (Sweden)

    Seik Weng Ng

    2009-05-01

    Full Text Available The Sn atom in the title compound, [Sn(C4H92(C7H14NS22], exists in a tetrahedral C2S2Sn coordination geometry. The geometry is distorted towards skew-trapezoidal-bipyramidal owing to the proximity of the double-bond S atoms [Sn—S = 2.521 (2 and Sn...S = 2.933 (2 Å]. The Sn atom lies on a special position of mm2 site symmetry and the tin-bound n-butyl chain is disordered about a mirror plane. The ethyl and n-butyl groups of the dithiocarbamate unit are disordered about another mirror plane.

  6. Pulmonary embolism after endoscopic injection with N-butyl-2-cyanoacrylate for gastric varices

    Directory of Open Access Journals (Sweden)

    Gabriela Robaina

    2016-12-01

    Full Text Available Gastric varices occur in one-third of patients with portal hypertension. Bleeding from gastric varices remains a significant cause of death. Currently the first-line of treatment for gastric varices is endoscopic obliteration with N-butyl-2-cyanoacrylate. Though relatively safe, this option has several well-known complications. We report the case of a 61-year-old male patient with cryptogenic cirrhosis, who presented with fever, tachycardia and hypoxemia after endoscopic obliteration with N-butyl-2-cyanoacrylate. Radiographic findings were consistent with pulmonary embolism of the sclerosing substance. The aim of this case report is to emphasize the clinical and radiological findings of this complication in order to distinguish it from other similar medical conditions and prevent a delay in diagnosis

  7. Thermodynamic Properties of Hydrogen + Tetra-n-Butyl Ammonium Bromide Semi-Clathrate Hydrate

    Directory of Open Access Journals (Sweden)

    Shunsuke Hashimoto

    2010-01-01

    Full Text Available Thermodynamic stability and hydrogen occupancy on the hydrogen + tetra-n-butyl ammonium bromide semi-clathrate hydrate were investigated by means of Raman spectroscopic and phase equilibrium measurements under the three-phase equilibrium condition. The structure of mixed gas hydrates changes from tetragonal to another structure around 95 MPa and 292 K depending on surrounding hydrogen fugacity. The occupied amount of hydrogen in the semi-clathrate hydrate increases significantly associated with the structural transition. Tetra-n-butyl ammonium bromide semi-clathrate hydrates can absorb hydrogen molecules by a pressure-swing without destroying the hydrogen bonds of hydrate cages at 15 MPa or over.

  8. Dissolution of wood flour and lignin in 1-butyl-3-methyl-1-imidazolium chloride

    Directory of Open Access Journals (Sweden)

    Yasmin Nasiri Khonsari

    2013-10-01

    Full Text Available The ionic solvent, 1-butyl-3-methyl imidazolium chloride was used to dissolve the samples. Two lignocellulosic material including bagasse soda lignin and Populus deltoides wood flour were used. One gram of samples were dissolved in 10 ml ionic solvent, 1-butyl-3-methyl- imidazolium chloride at 70 ºC for 72 h while stirring with a magnetic stirrer. The wood flour and lignin samples were acetylated with addition of acetic anhydride to each container with a ratio of 0.25 ml/ 0.25 ml. The samples were heated for 3 days at 110 ° C. Two control samples (without acetylation and two treatments (acetylation were used. The functional groups were determined using FT-IR Spectrometer. The number and type of carbon and their structure were examined using 13CNMR Spectrometer. The guaiacyl, syringyl, coniferyl alcohol and biphenyls structures were identified.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mark H.

    2011-07-13

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

  10. The oxidation of 2,6-di-tert-butyl-4-methylphenol

    Science.gov (United States)

    Yohe, G.R.; Dunbar, J.E.; Pedrotti, R.L.; Scheidt, F.M.; Lee, F.G.H.; Smith, E.C.

    1956-01-01

    The products formed in the oxidation of 2,6-di-tert-butyl-4-methylphenol with oxygen and sodium hydroxide at about 100?? are 3,5-di-tert-butyl-4-hydroxybenzaldehyde, trimethylacetic acid, an acidic compound C14H22O3, and probably 2,6-di-tert-butylbenzoquinone (which was actually isolated in the similar oxidation of the above-named benzaldehyde), in addition to compounds previously reported. Some of the properties of C14H22O3 are given, and the oxidation of it to 2,3-di-tert-butylsuccinic anhydride is described, but assignment of structure is reserved pending the completion of more experimental work.

  11. MICROWAVE-ASSISTED PREPARATION OF 1-BUTYL-3-METHYLIMIDAZOLIUM TETRACHLOROGALLATE AND ITS CATALYTIC USE IN ACETAL FORMATION UNDER MILD CONDITIONS

    Science.gov (United States)

    1-Butyl-3-methylimidazolium tetrachlorogallate, [bmim][GaCl4], prepared via microwave-assisted protocol, is found to be an active catalyst for the efficient acetalization of aldehydes under mild conditions.

  12. Small-angle neutron scattering studies of sodium butyl benzene sulfonate aggregates in aqueous solution

    Indian Academy of Sciences (India)

    O R Pal; V G Gaikar; J V Joshi; P S Goyal; V K Aswal

    2004-08-01

    The aggregation behaviour of a hydrotrope, sodium -butyl benzene sulfonate (Na-NBBS), in aqueous solutions is investigated by small-angle neutron scattering (SANS). Nearly ellipsoidal aggregates of Na-NBBS at concentrations well above its minimum hydrotrope concentration were detected by SANS. The hydrotrope seems to form self-assemblies with aggregation number of 36–40 with a substantial charge on the aggregate. This aggregation number is weakly affected by the hydrotrope concentration.

  13. (2-tert-Butyl-5-hydroxymethyl-1,3-dioxan-5-ylmethanol

    Directory of Open Access Journals (Sweden)

    Berenice Vargas

    2012-07-01

    Full Text Available In the title compound, C10H20O4, the dioxane ring adopts a chair conformation. The tert-butyl group occupies an equatorial position, and is staggered with respect to the O atoms of the dioxane ring. In the crystal, molecules are connected by O—H...O hydrogen-bonds into zigzag chains of R44(8 and R22(12 ring motifs that run parallel to the a axis.

  14. 1-[(E-2-(5-tert-Butyl-2-hydroxyphenyldiazen-1-yl]naphthalen-2-ol

    Directory of Open Access Journals (Sweden)

    Hassiba Bougueria

    2014-02-01

    Full Text Available The non-H atoms of the title compound, C20H20N2O2, is located on a mirror plane except two methyl groups of the tert-butyl group. Intramolecular N—H...O hydrogen bonds exist between the hydroxy and diazenyl groups. In the crystal, molecules are linked by weak C—H...O hydrogen bonds into supramolecular chains running along the a-axis direction.

  15. Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Xiao Li-guang

    2016-01-01

    Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

  16. Synthesis and characterization of tris[butyl-(1-methyl-3-phenyl-propyl-dithiocarbamato]-cobalt(III seskvitoluene

    Directory of Open Access Journals (Sweden)

    TIBOR SABO

    2002-02-01

    Full Text Available A new bidentate ligand butyl-(1-methyl-3-phenyl-propyl-dithiocarbamate (bmFpdtc was prepared, as the sodium salt. In the reaction of hexaaminecobalt(III chloride with NabmFpdtc, the corresponding tris[butyl-(1-methyl-3-phenyl-propyl-dithiocarbamato]cobalt(III, [Co(bmFpdtc3] complex was prepared. The complex was characterized by elemental analysis, infrared, electronic absorption, 1H and 13C-NMR spectroscopy.

  17. Reaction kinetics for synthesis of sec-butyl alcohol catalyzed by acid-functionalized ionic liquid

    Institute of Scientific and Technical Information of China (English)

    Ting Qiu; Wenli Tang; Chenggang Li; Chengming Wu; Ling Li

    2015-01-01

    The acid-functionalized ionic liquid ([HSO3Pmim]HSO4) was synthesized by a two-step method. Nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FT-IR) show that the synthesis method is feasible and high purity of ionic liquid can be obtained. Using [HSO3Pmim]HSO4 as the catalyst, we studied the reaction kinetics of synthesizing sec-butyl alcohol from sec-butyl acetate and methanol by transesterification in a high-pressure batch reactor. The effects of temperature, initial molar ratio of methanol to ester, and catalyst concentration on the conversion of sec-butyl acetate were studied. Based on its possible reaction mechanism, a ho-mogeneous kinetic model was established. The results show that the reaction heatΔH is 10.94 × 103 J·mol−1, so the reaction is an endothermic reaction. The activation energies Ea+and Ea−are 60.38 × 103 and 49.44 × 103 J·mol−1, respectively.

  18. Vapour phase alkylation of ethylbenzene with -butyl alcohol over mesoporous Al-MCM-41 molecular sieves

    Indian Academy of Sciences (India)

    V Umamaheswari; M Palanichamy; Banumathi Arabindoo; V Murugesan

    2002-06-01

    The alkylation of ethylbenzene with -butyl alcohol was studied over Al-MCM-41 (Si/Al = 50 and 90) and Al, Mg-MCM-41 (Si/(Al + Mg) =50) in the vapour phase from 200 to 400°C. The products were --butylethylbenzene (--BEB), --butylvinylbenzene (--BVB) and --butylethylbenzene ( --BEB). Ethylbenzene conversion decreased with increase in temperature and increase in the ethylbenzene content of the feed. The reaction between the freely diffusing ethylbenzene in the channel and the -butyl cations remaining as charge compensating ions yielded --BEB. --BVB, an unexpected product in this investigation, was produced by dehydrogenation of --BEB over alumina particles present in the channels of the molecular sieves. Adsorption of ethylbenzene on Brønsted acid sites and its subsequent reaction with very closely adsorbed -butyl cations proved to be necessary to obtain --BEB. Though --BEB was obtained, the corresponding --butylvinylbenzene was not observed in this study. Study of time durations indicated rapid and slow catalyst deactivation at lower and higher streams respectively.

  19. Comprehensive testing to measure the response of butyl rubber to Hanford tank waste simulant

    Energy Technology Data Exchange (ETDEWEB)

    NIGREY,PAUL J.

    2000-05-01

    This report presents the findings of the Chemical Compatibility Program developed to evaluate plastic packaging components that may be incorporated in packaging mixed-waste forms for transportation. Consistent with the methodology outlined in this report, the authors performed the second phase of this experimental program to determine the effects of simulant Hanford tank mixed wastes on packaging seal materials. That effort involved the comprehensive testing of five plastic liner materials in an aqueous mixed-waste simulant. The testing protocol involved exposing the materials to {approximately}143, 286, 571, and 3,670 krad of gamma radiation and was followed by 7-, 14-, 28-, 180-day exposures to the waste simulant at 18, 50, and 60 C. Butyl rubber samples subjected to the same protocol were then evaluated by measuring seven material properties: specific gravity, dimensional changes, mass changes, hardness, compression set, vapor transport rates, and tensile properties. From the analyses, they determined that butyl rubber has relatively good resistance to radiation, this simulant, and a combination of these factors. These results suggest that butyl rubber is a relatively good seal material to withstand aqueous mixed wastes having similar composition to the one used in this study.

  20. Synthesis and Structure of an Octopus-like Octapropargyl Tetra-iso-butyl-resorcin[4]arene

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang; LIU Yu-Jie; ZHANG Qian-Feng

    2005-01-01

    Treatment of tetra-iso-butyl-resorcin[4]arene 1 with propargyl bromide in the presence of K2CO3 as base gave an octopus-like octapropargyl tetra-iso-butyl-resorcin[4]arene 2 (C68H72O8, Mr = 1017.26) in a quantitative yield.Single-crystal structure of 2 was determined by X-ray crystallography.2 crystallizes in the monoclinic system, space group P21/n with a =13.3247(6), b = 24.7929(11), c = 19.1810(9)(。A), β= 109.272(1)°, V= 5981.5(5)(。A)3, Dc.= 1.130 g/cm3, μ = 0.073 mm-1, F(000) = 2176 and Z = 4.Overall structure of 2 reveals an octopus-like resorcinarene with eight propargyl groups in different directions.The resorcinarene adopts the boat conformation where the iso-butyl residues act as four-legged piano stool.The two opposite aryl rings of the macrocyclic framework are almost coplanar, and the two others facing each other are perpendicular to this plane.

  1. Synthesis and Characterization of a Gasoline Oxygenate, Ethyl tert-Butyl Ether

    Science.gov (United States)

    Donahue, Craig J.; D'Amico, Teresa; Exline, Jennifer A.

    2002-06-01

    A laboratory procedure involving the synthesis and characterization of ethyl tert-butyl ether (ETBE) is described. This experiment has been used in a general chemistry sequence that includes a section on organic chemistry, but is also well suited for an introductory organic chemistry laboratory course. ETBE is prepared by the acid-catalyzed reaction of tert-butyl alcohol with ethyl alcohol. The product is recovered as a low-boiling azeotrope and purified by liquid liquid extraction with water. By using gas chromatography and IR spectroscopy to examine both the crude and the purified products, students can see how much the purity of their sample improves. They can also appreciate the value of these methods (especially GC) as tools to establish purity. Student results are presented. The use of ETBE and its more prominent cousin methyl tert-butyl ether (MTBE) as gasoline oxygenates has become very controversial because they have polluted underground water supplies. This lab permits students to prepare a compound that has a real use and regularly makes headlines in the news. This lab experiment is part of an effort to develop a general chemistry sequence for engineering students using the theme of "Chemistry and the Automobile".

  2. Different mechanisms of formation of glutathione-protein mixed disulfides of diamide and tert-butyl hydroperoxide in rat blood.

    Science.gov (United States)

    Di Simplicio, P; Lupis, E; Rossi, R

    1996-03-15

    The mechanisms of glutathione-protein mixed disulfide (GSSP) formation caused by diamide and tert-butyl hydroperoxide were studied in rat blood after in vitro treatment in the 0.3-4 mM dose range. tert-Butyl hydroperoxide formed GSSP, via GSSG, according to the reaction, GSSG + PSH --> GSSP + GSH, whereas diamide reacted first with protein SH groups, giving PS-diamide adducts and then, after reaction with GSH, GSSP. Moreover, after diamide treatment, GSSP patterns were characterized by a much slower or irreversible dose-related return to basal levels in comparison with those observed with tert-butyl hydroperoxide, always reversible. Experiments with purified hemoglobin revealed the existence of a large fraction of protein SH groups which formed GSSP and had a higher reactivity than GSH. Experiments on glucose consumption and role of various erythrocyte enzymes, carried out to explain the inertness of GSSP to reduction after treatment of blood with diamide, were substantially negative. Other tests carried out to confirm the efficiency of the enzymatic machinery of blood samples successively treated with diamide and tert-butyl hydroperoxide, indicated that GSSP performed by diamide was difficult to reduce, whereas those generated by tert-butyl hydroperoxide were reversible as normal. Our results suggest that a fraction of GSSP generated by diamide is different and less susceptible to reduction than that obtained with tert-butyl hydroperoxide.

  3. 5-tert-Butyl-2-[5-(5-tert-butyl-1,3-benzoxazol-2-yl-2-thienyl]-1,3-benzoxazole

    Directory of Open Access Journals (Sweden)

    Fang-Fang Jian

    2008-12-01

    Full Text Available The title compound, C26H26N2O2S, was prepared by the reaction of thiophene-2,5-dicarboxylic acid and 2-amino-4-tert-butylphenol. One of the tert-butyl groups is disordered over two conformations, with occupancies of 0.539 (1 and 0.461 (2. The two 1,3-benzoxazole rings are almost planar, with dihedral angles of 0.83 (18 and 1.64 (17° between the five- and six-membered rings. The thiophene ring makes dihedral angles of 21.54 (19 and 4.49 (18° with the planes of the five-membered oxazole rings. The crystal packing is controlled by π–π stacking interactions involving the thiophene and benzene rings, with a centroid–centroid distance of 3.748 (2 Å.

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

    Directory of Open Access Journals (Sweden)

    A Eslami

    2009-06-01

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

  5. Effect of layered silicate on the barrier properties of cured butyl rubber

    Energy Technology Data Exchange (ETDEWEB)

    Krzeminska, S [Central Institute for Labour Protection - National Research Institute, Department of Personal Equipment, Wierzbowa 48, 90-133 Lodz (Poland); Rzymski, W M [Technical University of Lodz, Institute of Polymer and Dye Technology, Stefanowskiego 12/16, 90-924 Lodz (Poland)], E-mail: sykrz@ciop.lodz.pl

    2009-01-01

    The aim of the study was to investigate the effect of layered silicate nanofiller (bentonite: Nanofil 15, Poro Additive) on the barrier properties of non-polar butyl rubber (the IIR, BK 1675 N brand) conventionally cured with sulphur in respect of selected organic solvents. The barrier properties were assessed on the basis of determination of standarized breakthrough time for cured IIR exposed to the selected solvents with different thermodynamic affinities to IIR, i.e. polar butyl acetate and non-polar cyclohexane. In the case of the non-polar solvent - cyclohexane - no effect of the content of the layered silicate (5 - 20 phr) on improvement of barrier properties of the tested IIR vulcanizates was observed. In contrast, a favorable effect of the silicate nanofiller was observed in the case of the polar solvent - butyl acetate, for which the breakthrough time tested for filler-containing vulcanizate (10 - 20 phr) reached 160 -200 min, whereas the breakthrough time obtained for unfilled vulcanizate was 129 min only. The testing of barrier properties of IIR vulcanizates containing various fillers (layered silicate Nanofil 15 and active silica Ultrasil VN3) added in the amount of 20 phr, indicate the favorable effect of layered silicate only in tests with the polar solvent used (an increase in breaktrhough time from 129 to 164 min). Contrary, the presence of conventional silica leads to decrease of breakthrough time (to 118 min). In the case of the non-polar solvent, no effect of the filler type on barrier properties of the tested vulcanizates was observed.

  6. Ascorbate protects against tert-butyl hydroperoxide inhibition of erythrocyte membrane Ca2+ + Mg2(+)-ATPase.

    Science.gov (United States)

    Moore, R B; Bamberg, A D; Wilson, L C; Jenkins, L D; Mankad, V N

    1990-05-01

    The incubation of erythrocyte suspensions or isolated membranes containing a residual amount of hemoglobin (0.04% of original cellular hemoglobin) with tert-butyl hydroperoxide (tBHP, 0.5 mM) caused significant inhibition of basal and calmodulin-stimulated Ca2+ + Mg2(+)-ATPase activities and the formation of thiobarbituric acid reactive products measured as malondialdehyde. In contrast, the treatment of white ghosts (membranes not containing hemoglobin) with tBHP (0.5 mM) did not lead to appreciable enzyme inhibition within the first 20 min and did not result in malondialdehyde (MDA) formation. However, the addition of either 10 microM hemin or 100 microM ferrous chloride + 1 mM ADP to white ghosts produced hydroperoxide effects similar to those in pink ghosts (membranes with 0.04% hemoglobin). The concentrations of hemin and ferrous chloride which caused half-maximal inhibition of Ca2+ + Mg2(+)-ATPase activity at 10 min were 0.5 and 30 microM, respectively. The effects of several antioxidants (mannitol, thiourea, hydroxyurea, butylated hydroxytoluene, and ascorbate) were investigated for their protective effects against oxidative changes resulting from tBHP treatment. Over a 30-min incubation period only ascorbate significantly reduced the enzyme inhibition, MDA formation, and protein polymerization. Thiourea and hydroxyurea decreased MDA formation and protein polymerization but failed to protect against the enzyme inhibition. Butylated hydroxytoluene was similar to thiourea and hydroxyurea but with better protection at 10 min. Mannitol, under these conditions, was an ineffective antioxidant for all parameters tested.

  7. Forensic analysis of tertiary-butyl alcohol (TBA) detections in a hydrocarbon-rich groundwater basin.

    Science.gov (United States)

    Quast, Konrad W; Levine, Audrey D; Kester, Janet E; Fordham, Carolyn L

    2016-04-01

    Tertiary-butyl alcohol (TBA), a high-production volume (HPV) chemical, was sporadically detected in groundwater and coalbed methane (CBM) wells in southeastern Colorado's hydrocarbon-rich Raton Basin. TBA concentrations in shallow water wells averaged 75.1 μg/L, while detections in deeper CBM wells averaged 14.4 μg/L. The detection of TBA prompted a forensic investigation to try to identify potential sources. Historic and recent data were reviewed to determine if there was a discernable pattern of TBA occurrence. Supplemental samples from domestic water wells, monitor wells, CBM wells, surface waters, and hydraulic fracturing (HF) fluids were analyzed for TBA in conjunction with methyl tertiary-butyl ether (MTBE) and ethyl tertiary-butyl ether (ETBE), proxies for evidence of contamination from reformulated gasoline or associated oxygenates. Exploratory microbiological sampling was conducted to determine if methanotrophic organisms co-occurred with TBA in individual wells. Meaningful comparisons of historic TBA data were limited due to widely varying reporting limits. Mapping of TBA occurrence did not reveal any spatial patterns or physical associations with CBM operations or contamination plumes. Additionally, TBA was not detected in HF fluids or surface water samples. Given the widespread use of TBA in industrial and consumer products, including water well completion materials, it is likely that multiple diffuse sources exist. Exploratory data on stable isotopes, dissolved gases, and microbial profiling provide preliminary evidence that methanotrophic activity may be producing TBA from naturally occurring isobutane. Reported TBA concentrations were significantly below a conservative risk-based drinking water screening level of 8000 μg/L derived from animal toxicity data.

  8. Isobaric vapor-liquid equilibria in the system methyl propanoate + n-butyl alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Susial, P.; Ortega, J. (Univ. de Las Palmas de Gran Canaria, Canary Islands (Spain). Lab. de Termodinamica y Fisicoquimica)

    1993-10-01

    Isobaric vapor-liquid equilibria were determined at 74.66, 101.32, and 127.99 kPa for binary mixtures containing methyl propanoate + n-butyl alcohol by using a dynamic still with vapor and liquid circulation. No azeotrope was detected. The data were found to be thermodynamically consistent according to the point to point test. Application of the group-contribution models ASOG, UNIFAC, and modified UNIFAC to the activity coefficients at the three pressures studied gives average errors of less than 10%, 11%, and 3%, respectively.

  9. Kinetic Study of Np(Ⅵ) Reduction With Tert-butyl Hydrazine

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tert-butyl hydrazine(TBH) is a new salt free reductant, it can effectively reduce Np(Ⅵ) to Np(Ⅴ) but reduce Pu(Ⅳ)very slowly. Further more, it has the highest ratio of rate constant for Np(Ⅵ) reduction to the rate constant for Pu(Ⅳ) reduction in hydrazine derivatives, so it’s a promising reductant to separate Np, Pu effectively,Reduction kinetic study of the reaction in nitric acid is performed by spectrophotometry. The effect of some factors such as concentration of TBH, HNO3, Np(Ⅵ) and temperature on the redox

  10. Effect of Counteranions on the Conformational Equilibrium of 1-Butyl-3-methylimidazolium-Based Ionic Liquids

    OpenAIRE

    Naohiro Hatano; Takahiro Takekiyo; Hiroshi Abe; Yukihiro Yoshimura

    2011-01-01

    We have investigated the nonspherical anion effect on the trans-trans (TT) and gauche-trans (GT) equilibrium in pure 1-butyl-3-methylimidazolium ([bmim]+)-based room temperature ionic liquids (RTILs) by the Raman spectroscopy. The intensity ratio of the [bmim]+ cation in [bmim]+-based RTILs having nonspherical anions changes with nature of the anions. However, the enthalpy change of the [bmim]+ cation is approximately −1.0 kJ/mol for all [bmim]+-based RTILs used in this study and is independe...

  11. Photo catalytic degradation of methyl tert-Butyl Ether (MTBE) from contaminated water: complete mineralization

    Energy Technology Data Exchange (ETDEWEB)

    Eslami, A.; Nasseri, S.; Maleki, A.; Aghvami, T.

    2009-07-01

    Methyl tert-butyl ether (MTBE) has been commercially used as an octane enhancer to replace tetraethyl lead in gasoline since 1979. The high mobility, water solubility, and resistance to natural attenuation associated with MTBE may result in contamination of ground and surface waters. In this investigation the degradation of aqueous MTBE at relatively high concentrations was studied by UV-vis/TiO{sub 2}/O{sub 2} photo catalytic process. The effect of important operational parameters such as ph, oxygen flow, catalyst loading, and irradiation time were also studied. (Author)

  12. TRANS-ARTERIAL EMBOLIZATION WITH N-BUTYL CYANOACRYLATE GLUE FOR RENAL BLEEDING: Case Report

    Directory of Open Access Journals (Sweden)

    Benny Young

    2014-08-01

    Full Text Available Background: The objectivity in management of renal bleeding is to preserve a significant renal parenchyma tissue and prevent associated morbidities like anemic shock or renal impairment from substantial nephron demise or obstructed uropathy. Trans-arterial embolization therapy by interventional radiology offers a high success rate with potential of reserving normal renal tissue. The selection material for renal arterial embolization largely depends on vasculature anatomy and end-point of procedure. N-butyl cyanoacrylate glue in our experience is applied in lesion supplied by small size of end-artery. 

  13. Organophosphazenes. 15. Reactions of Hexafluorocyclotriphosphazene with Tert- and n-Butyl Lithium Reagents

    Science.gov (United States)

    1981-12-04

    appears to be the preferred pathway in most organo - 43lithium reactions. The H NMR spectrum of the bis t-butyl derivative (II) shows a doublet 3with J...34 168(19.4%, N3P3FCI2+), 167 (39.5%, N3P3CH +), 149(42.7%, N3P3 CH2 ) N3P3 F 3 (t-C 4H9 ) 3 (111) 36(8.%,N CH+ 3d (2.%,N PFrU .363(87.73, N3P3F3C 1 2 12 7

  14. Crystal structure of 4-azidomethyl-6-tert-butyl-2H-chromen-2-one

    Directory of Open Access Journals (Sweden)

    Nasseem El-Khatatneh

    2015-04-01

    Full Text Available In the title compound, C14H15N3O2, one of the methyl C atoms of the tert-butyl group lies almost in the plane of the chromene ring system [deviation = −0.097 (2 Å], one lies above and one lies below [deviations = 1.460 (3 and 1.006 (3 Å, respectively]. The C—C—N—N torsion angle is 142.33 (17°. In the crystal, moelcules are linked by weak C—H...O hydrogen bonds to generate C(6 chains propagating in the [010] direction.

  15. Study of toxicity of butylated hydroxyanisole (BHA) in pregnant gilts and their foetuses.

    Science.gov (United States)

    Hansen, E V; Meyer, O; Olsen, P

    1982-01-01

    An embryotoxicity study on butylated hydroxyanisole (BHA) was carried out in SPF pigs (Danish Landrace). BHA was incorporated in the diet and administered to pigs in doses of 0, 50, 200 and 400 mg/kg body wt/day from mating (artificial insemination) to day 110 of the gestation period, when the foetuses were removed. Significant lower weight gain was observed in the dams dosed 400 mg/kg body wt/day. Absolute and relative organ weight for the liver and thyroid gland showed a dose-related increase, BHA neither affected the reproduction data nor the incidence of defects in the foetuses.

  16. Synchrotron Photoionization Investigation of the Oxidation of Ethyl tert-Butyl Ether.

    Science.gov (United States)

    Winfough, Matthew; Yao, Rong; Ng, Martin; Catani, Katherine; Meloni, Giovanni

    2017-02-23

    The oxidation of ethyl tert-butyl ether (ETBE), a widely used fuel oxygenated additive, is investigated using Cl atoms as initiators in the presence of oxygen. The reaction is carried out at 293, 550, and 700 K. Reaction products are probed by a multiplexed chemical kinetics photoionization mass spectrometer coupled with the synchrotron radiation produced at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory. Products are identified on the basis of mass-to-charge ratio, ionization energies, and shape of photoionization spectra. Reaction pathways are proposed together with detected primary products.

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

    Energy Technology Data Exchange (ETDEWEB)

    Francois, A.

    2002-11-01

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

  18. BINDING OF THERMO-SENSITIVE AND pH-SENSITIVE BUTYLATED POLY(ALLYLAMINE)S WITH LYSOZYME

    Institute of Scientific and Technical Information of China (English)

    Jing-jing Liu; Yun-feng Yan; Ping Yao

    2011-01-01

    Butyl modified poly(allylamine)s with butyl substitution degrees of 15% to 70% were prepared. The polymers show pH sensitive property and lower critical solution temperature (LCST) behavior. The LCST appears at lower temperature, lower pH and lower polymer concentration for the polymer with higher butylated degree. The binding of native lysozyme with the polymers depends on the hydrophobicity of the polymers at the pH range that the protein and the polymer carry the same positive charges. The increase of polymer hydrophobicity can increase the binding with lysozyme, but the self-aggregation of the polymer decreases the binding. The bound lysozyme molecules can recover their native activity completely after the dissociation of the complexes. Compared with native lysozyme, the denatured one which exposes the hydrophobic residues can increase the binding with the polymer and form stable complex nanoparticles.

  19. Alkylation of Hydroquinone with tert-Butyl Alcohol over Bis[(perfluoroalkyl)sulfonyl]imides Supported on MCM-41

    Institute of Scientific and Technical Information of China (English)

    YUAN, Yu-Bin; NIE, Jin; ZHANG, Zheng-Bo; ZHOU, San-Yi

    2006-01-01

    Bis[(perfluoroalkyl)sulfonyl]imides [HN(SO2Rf)2, and Rf represents the perfluorinated alkyl group] supported on MCM-41 were synthesized and characterized by XRD, FTIR, SEM, TGA and N2-adsorption techniques. The supported catalysts, HN(SO2Rf)2/MCM-41, were used as the catalysts for the tert-butylation of hydroquinone (HQ)with tert-butyl alcohol (TBA) in the liquid phase. A high yield (52.0%) of 2-tert-butyl hydroquinone (TBHQ) could be obtained in the presence of 5 mol% HN(SO2C4F9)2/MCM-41 under the optimized reaction conditions and the heterogeneous catalyst could be recycled at least 6 times without substantial loss of activity.

  20. Esterification of levulinic acid to n-butyl levulinate over heteropolyacid supported on acid-treated clay

    Institute of Scientific and Technical Information of China (English)

    S.Dharne; V.V.Bokade

    2011-01-01

    Levulinic acid has been identified as a promising green, biomass-derived platform chemical, n-Butyl levulinate is used as an important intermediate having diverse applications.The present work focuses on the synthesis of n-butyl levulinate by esterification of levulinic acid with n-butanol using heteropolyacid (HPA) supported on acid-treated clay montmorillonite (K10).20% (w/w) dodecatungestophosphoric acid (DTPA) supported on K10 was found to be the most efficient catalyst with 97% levulinic acid conversion and 100% selectivity towards n-butyl levulinate.Effects of various process parameters were studied to examine the efficacy of 20% (w/w) DTPA/K10 for optimization of the activity.

  1. Higher levels of ethyl paraben and butyl paraben in rat amniotic fluid than in maternal plasma after subcutaneous administration

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Taxvig, Camilla; Hass, Ulla

    2008-01-01

    Parabens are a group of antimicrobial preservatives widely used in cosmetics, pharmaceuticals, and in foods. Previous in vitro and in vivo studies have shown weak estrogenic effects of some parabens. Thus, especially, exposure of fetus and infants via the mother is a matter of concern. In order...... to obtain more knowledge about the distribution of ethyl paraben and butyl paraben in pregnant rats and pups after perinatal exposure, the presented study was designed. The data show response and distribution of ethyl paraben and butyl paraben in maternal rat plasma, pools of amniotic fluids, placenta......, whole-body fetuses, and in fetal liver after dosing of dams with 100, 200, and 400 mg/kg body weight (bw)/day from gestational day 7 to 21. After cesarean section of dams, the fluids and tissues were collected, deconjugated, and purified by solid-phase extraction, and ethyl paraben and butyl paraben...

  2. Neutral Pd (II) and Ni (II) Acetylide Complexes as Single-Component Initiators for Polymerizations of Butyl Methacrylate and Acrylates

    Institute of Scientific and Technical Information of China (English)

    SUN,Hong-Mei(孙宏枚); YANG,Mu-Jie(杨慕杰); SHEN,Qi(沈琪)

    2001-01-01

    Homogeneous polymerization of butyl methacrylate (BMA)using Pd(II)- and Ni(n)-based acetyiide complexes as singlecomponent initiators has been investigated CHCl3 at 60°C.M(PPh)2(C≡CR)2 (M = Pti,Ni; R = Ph,CH2OH,CH2OOCCH3) were found to be a novel type of effective initiators for the polymerization of butyl methacrylate.Amongthem,Pd(PPh3)2(C≡CPh)2 (PPP) shows the highest activi-ty.Besides,PPP alone can also initiate the homogeneous poly-merizations of acrylates,e.g.,methyl acrylate (MA),andn-butyl acrylate (BA).The present type of polymerization isnot hindered by the incorporation of hydroquinone.``

  3. Butyl 2-(5-iodo-3-methylsulfinyl-1-benzofuran-2-ylacetate

    Directory of Open Access Journals (Sweden)

    Uk Lee

    2009-02-01

    Full Text Available In the title compound, C15H17IO4S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. The crystal structure is stabilized by weak intermolecular C—H...π interactions between a methyl H atom of the methylsulfinyl group and the benzene ring of the benzofuran system, and by an I...O halogen bond of 3.173 (3 Å and a nearly linear C—I...O angle of 171.7 (1°. In addition, the crystal structure exhibits weak intermolecular C—H...O hydrogen bonds. The O atom of the carbonyl group and the butyl chain are both disordered over two positions with site-occupancy factors from refinement of 0.55 (4 and 0.45 (4 (for the O atom, and 0.76 (2 and 0.24 (2 (for the butyl group.

  4. Post-discharge treatment of air effluents polluted by butyl-mercaptan: role of nitrate radical

    Science.gov (United States)

    Braci, L.; Ognier, S.; Liu, Y. N.; Cavadias, S.

    2011-01-01

    Dry air polluted by butyl-mercaptan was treated in a Dielectric Barrier Discharge (DBD) reactor at atmospheric pressure using air as plasmagene gas in discharge and post-discharge modes. The energy density was varied between 200 to 1300 J/L. To assess the treatment efficiency, the concentrations of buty-mercaptan, total Volatile Organic Compounds (VOCs) and SO2 were determined in the exhaust gas. Whatever the energy density was, the treatment efficiency was better in post-discharge mode. The butyl-mercaptan could be completely eliminated from 400 J/L and SO2 selectivity was always low, below 10%. Measurements of CO, CO2 and total VOCs indicated that 50 to 70% of the reaction products were condensed on the reactor wall in the form of micro-droplets, depending on the energy density. FTIR and XPS techniques were used to characterize the reaction products which were soluble in water. These analyses indicated that the reaction products contain oxygen, nitrogen and sulphur in an oxidized form. A reaction mechanism involving hydrogen abstraction from the -SH bond by the nitrate radical was proposed, pointing out the important role of nitrate radicals NO3 in the reactivity of air flowing post-discharge.

  5. Determination of methacrylic acid in food simulants by pyrolytic butylation-gas chromatography.

    Science.gov (United States)

    Huang, Zhongping; Qiu, Ruofeng; Liu, Tingfei; Huang, Yilei; Zhu, Zuoyi; Wang, Lili

    2016-07-08

    An on-line pyrolytic butylation approach was proposed to determine methacrylic acid (MA) in food simulants by gas chromatography (GC) without an expensive pyrolyzer. MA in food simulants was converted into butyl methacrylate in the presence of tetrabutylammonium hydroxide (TBAH) without any pretreatment at 330°C in the injection-port, contributing to high GC signal response. The derivatizing conditions for the proposed method were optimized, namely the injection-port temperature, type and amount of the organic alkaline used for derivatization. A series of standard solutions of MA in the range of 1.0-50mg/kg were analyzed with correlation coefficient r≥0.9975. The limits of detection (LODs) were less than 0.15mg/kg for MA in four matrix simulants (distilled water, 3%w/v acetic acid, 10%v/v ethanol, and isooctane). Relative standard deviations (RSDs) for retention time, peak height and peak area were all less than 3.88%. The technique was successfully applied to the analysis of MA migrating from plastic cup samples, with recoveries of added MA in the range of 96.5-123.0%. Direct injection of the simulants into the GC system after migration tests, without any pretreatment step, makes the developed method of great value for rapid screening analysis of samples in bulks.

  6. Gall stone dissolution with methyl tert-butyl ether: how to avoid complications.

    Science.gov (United States)

    Hellstern, A; Leuschner, M; Frenk, H; Dillinger, H W; Caspary, W; Leuschner, U

    1990-01-01

    Fifty of 52 patients with cholesterol gall bladder stones were treated with methyl tert-butyl ether. In 48 of 50 (96%) patients the stones dissolved after an average interval of 9.5 hours. Mean stone size was 1.7 cm (0.5-3.3 cm), mean stone number was 14.6 (1-70). Twelve patients (24%) complained of nausea, a burning sensation, or vomiting. In one patient bile leakage occurred and another suffered haematobilia (4%). The puncture set was improved, and a special basket was developed to extract stones that had escaped into the cystic duct. To prevent bile leakage or haemorrhage from the incision channel, a tissue adhesive was injected into the channel or ceruletid was administered subcutaneously before removing the catheter to induce contraction of the gall bladder. Thus we were able to treat 44 patients without any complications. Nausea and vomiting could be reduced if the treatment time was kept short and the perfusion volume was as low as possible. Methyl tert-butyl ether treatment is a successful treatment of gall bladder stones with few complications. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:2387519

  7. Electric Heating Property from Butyl Rubber-Loaded Boron Carbide Composites

    Institute of Scientific and Technical Information of China (English)

    MENG Dechuan; WANG Ninghui; LI Guofeng

    2014-01-01

    We researched the electric heating property from butyl rubber-loaded boron carbide composite. The effects of boron carbide content on bulk resistivity, voltage-current characteristic, thermal conductivity and thermal stability of boron carbide/butyl rubber (IIR) polymer composite were introduced. The analysis results indicated that the bulk resistivity decreased greatly with increasing boron carbide content, and when boron carbide content reached to 60%, the bulk resistivity achieved the minimum. Accordingly, electric heating behavior of the composite is strongly dependent on boron carbide content as well as applied voltage. The content of boron carbide was found to be effective in achieving high thermal conductivity in composite systems. The thermal conductivity of the composite material with added boron carbide was improved nearly 20 times than that of the pure IIR. The thermal stability test showed that, compared with pure IIR, the thermal stable time of composites was markedly extended, which indicated that the boron carbide can significantly improve the thermal stability of boron carbide/IIR composite.

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

    Directory of Open Access Journals (Sweden)

    Shanshan Li

    2016-09-01

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

  9. Structural elucidation of 4-(cystein-S-yl)butyl glucosinolate from the leaves of Eruca sativa.

    Science.gov (United States)

    Kim, Sun-Ju; Kawaharada, Chiami; Jin, Shigeki; Hashimoto, Makoto; Ishii, Gensho; Yamauchi, Hiroaki

    2007-01-01

    The structurally unique glucosinolate (GSL), 4-(cystein-S-yl)butyl GSL, was identified in the leaves of hydroponically-grown rocket salad (Eruca sativa Mill.). Its electrospray ionization mass spectrometry (ESI-MS)/MS spectrum indicated that this unusual GSL had a molecular weight of 414 as a desulfo (DS)-GSL, and a molecular formula of C(14)H(25)N(2)O(8)S(2) based on its negative ion matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) spectrum. For further confirmation, the 4-(cystein-S-yl)butyl DS-GSL was prepared with authentic L-Ser and purified dimeric 4-mercaptobutyl DS-GSL, and its chemical structure then confirmed by ESI-MS/MS data. It is named "glucorucolamine" as a trivial name from its ammonia sensitivity. This unique GSL was found to the greatest extent when rocket salad was grown in a 100% NH4+-N nutrient solution. Despite it clearly seems to reduce the detoxification of excess NH4+ in the leaves of rocket salad, present knowledge about the unique GSL is still far from being sufficient.

  10. Hydrolysis of the quinone methide of butylated hydroxytoluene in aqueous solutions.

    Science.gov (United States)

    Willcockson, Maren Gulsrud; Toteva, Maria M; Stella, Valentino J

    2013-10-01

    Butylated hydroxytoluene or BHT is an antioxidant commonly used in pharmaceutical formulations. BHT upon oxidation forms a quinone methide (QM). QM is a highly reactive electrophilic species that can undergo nucleophilic addition. Here, the kinetic reactivity of QM with water at various apparent pH values in a 50% (v/v) water-acetonitrile solution at constant ionic strength of I = 0.5 (NaCl)4 , was studied. The hydrolysis of QM in the presence of added acid, base, sodium chloride, and phosphate buffer resulted in the formation of only one product--the corresponding 3,5-di-tert-butyl-4-hydroxybenzyl alcohol (BA). The rate of BA formation was catalyzed by the addition of acid and base, but not chloride and phosphate species. Nucleophilic excipients, used in the pharmaceutical formulation, or nucleophilic groups on active pharmaceutical ingredient molecule may form adducts with QM, the immediate oxidative product of BHT degradation, thus having implications for drug product impurity profiles. Because of these considerations, BHT should be used with caution in formulations containing drugs or excipients capable of acting as nucleophiles.

  11. Effect of butyl paraben on the development and microbial composition of periphyton.

    Science.gov (United States)

    Song, Chaofeng; Lin, Juan; Huang, Xiaolong; Wu, Yonghong; Liu, Jiantong; Wu, Chenxi

    2016-03-01

    Parabens are extensively used as preservatives and bactericides in personal care and other consumer products, and are commonly found in wastewater and surface water as contaminants. However, few data are currently available on the ecotoxicity of parabens. Periphyton biofilm, a widely distributed microbial aggregate of ecological importance in aquatic environment, is frequently used for water quality monitoring, ecological restoration, and toxicity assessment. In this work, the effects of butyl paraben on the development and microbial composition of periphyton biofilm was studied in a laboratory experiment for 32 days using flow through channels. No effect was observed at the environmental relevant concentration level (0.5 μg L(-1)) during the experiment. At the highest tested concentration level (5000 μg L(-1)), following effects were noted: (1) inhibition on algae growth at the end of the experiment as indicated by the chlorophyll a and total biovolume; (2) inhibition of photosynthetic efficiency on day 24 as suggested by the maximal Photosystem II quantum yield (Fv/Fm); (3) decrease of the algal diversity on day 24 and 32 as reflected by the Pielou and Shannon-Weiner indices. Bacteria were less sensitive than algae in the periphyton biofilm, which showed no difference at all tested concentration levels as illustrated by the Biolog EcoPlates™ analysis. Therefore, we conclude that environmental residues of butyl paraben have a very low risk to periphyton in aquatic ecosystems.

  12. Production of fatty acid butyl esters using the low cost naturally immobilized Carica papaya lipase.

    Science.gov (United States)

    Su, Erzheng; Wei, Dongzhi

    2014-07-01

    In this work, the low cost naturally immobilized Carica papaya lipase (CPL) was investigated for production of fatty acid butyl esters (FABE) to fulfill the aim of reducing the lipase cost in the enzymatic butyl-biodiesel process. The CPL showed specificities to different alcohol acyl acceptors. Alcohols with more than three carbon atoms did not have negative effects on the CPL activity. The CPL catalyzed butanolysis for FABE production was systematically investigated. The reaction solvent, alcohol/oil molar ratio, enzyme amount, reaction temperature, and water activity all affected the butanolysis process. Under the optimized conditions, the highest conversion of 96% could be attained in 24 h. These optimal conditions were further applied to CPL catalyzed butanolysis of other vegetable oils. All of them showed very high conversion. The CPL packed-bed reactor was further developed, and could be operated continuously for more than 150 h. All of these results showed that the low cost Carica papaya lipase can be used as a promising lipase for biodiesel production.

  13. Method for determination of methyl tert-butyl ether in gasoline by gas chromatography.

    Science.gov (United States)

    Achten, C; Püttmann, W

    2001-03-02

    A simple method for the determination of methyl tert-butyl ether (MTBE) in gasoline has been developed. The separation of MTBE from other analytes was controlled by the use of gas chromatography-mass spectrometry in the full scan mode using the characteristic primary, secondary and tertiary ions m/z 73, 57 and 43. The sample mass spectrum did not show any superimposition of other analytes. The separation from the common gasoline component 2-methylpentane was sufficient for reliable quantitation. An application of the developed conditions using gas chromatography with flame ionization detection was performed by the analysis of regular, euro super, super premium unleaded and 'Optimax' gasoline from petrol stations in the area of Frankfurt/Main, Germany. Regular unleaded gasoline shows an average MTBE content of 0.4% (w/w), whereas the MTBE content in euro super gasoline varies between 0.4 and 4.2% (w/w). The blending of MTBE to super premium has increased from 8.2% (w/w) in 1998 to 9.8% (w/w) on average in 1999. The recently introduced gasoline 'Optimax' shows an average MTBE content of 11.9% (w/w). The presented method might also be used for the analysis of other ethers, such as ethyl tert-butyl ether, which requires the use of another internal standard.

  14. Degradation of tert-butyl formate and its intermediates by an ozone/UV process.

    Science.gov (United States)

    Garoma, Temesgen; Gurol, Mirat D; Thotakura, Lalitha; Osibodu, Olufisayo

    2008-12-01

    In this paper, the oxidation of tert-butyl formate (TBF) in aqueous solution by an ozone/UV process was described. The oxidation process was investigated experimentally in a semibatch reactor. The results of the study indicated that the ozone/UV process was very effective in oxidizing TBF. tert-Butyl alcohol (TBA), hydroxy-iso-butyraldehyde (HiBA), acetone, formaldehyde, and formic acid were identified as major primary intermediates during the oxidation of TBF. About 90% organic carbon balance was obtained indicating that most reaction intermediates have been identified and quantified. Some of the primary intermediates were also oxidized in the ozone/UV system. Accordingly, HiBA, acetone, formaldehyde, and formic acid were the primary intermediates of TBA oxidation. The oxidation of acetone in the ozone/UV system generated formaldehyde, pyruvaldehyde, acetic acid, formic acid as primary intermediates. It was also observed that the reaction intermediates formed during the oxidation of TBF react well in the ozone/UV system and complete mineralization could be achieved by the process.

  15. Ethyl tert-butyl ether (ETBE)-degrading microbial communities in enrichments from polluted environments.

    Science.gov (United States)

    Le Digabel, Yoann; Demanèche, Sandrine; Benoit, Yves; Fayolle-Guichard, Françoise; Vogel, Timothy M

    2014-08-30

    The ethyl tert-butyl ether (ETBE) degradation capacity and phylogenetic composition of five aerobic enrichment cultures with ETBE as the sole carbon and energy source were studied. In all cases, ETBE was entirely degraded to biomass and CO2. Clone libraries of the 16S rRNA gene were prepared from each enrichment. The analyses of the DNA sequences obtained showed different taxonomic compositions with a majority of Proteobacteria in three cases. The two other enrichments have different microbiota with an abundance of Acidobacteria in one case, whereas the microbiota in the second was more diverse (majority of Actinobacteria, Chlorobi and Gemmatimonadetes). Actinobacteria were detected in all five enrichments. Several bacterial strains were isolated from the enrichments and five were capable of degrading ETBE and/or tert-butyl alcohol (TBA), a degradation intermediate. The five included three Rhodococcus sp. (IFP 2040, IFP 2041, IFP 2043), one Betaproteobacteria (IFP 2047) belonging to the Rubrivivax/Leptothrix/Ideonella branch, and one Pseudonocardia sp. (IFP 2050). Quantification of these five strains and two other strains, Rhodococcus sp. IFP 2042 and Bradyrhizobium sp. IFP2049, which had been previously isolated from one of the enrichments was carried out on the different enrichments based on quantitative PCR with specific 16S rRNA gene primers and the results were consistent with the hypothesized role of Actinobacteria and Betaproteobacteria in the degradation of ETBE and the possible role of Bradyrhizobium strains in the degradation of TBA.

  16. Higher levels of ethyl paraben and butyl paraben in rat amniotic fluid than in maternal plasma after subcutaneous administration.

    Science.gov (United States)

    Frederiksen, Hanne; Taxvig, Camilla; Hass, Ulla; Vinggaard, Anne M; Nellemann, Christine

    2008-12-01

    Parabens are a group of antimicrobial preservatives widely used in cosmetics, pharmaceuticals, and in foods. Previous in vitro and in vivo studies have shown weak estrogenic effects of some parabens. Thus, especially, exposure of fetus and infants via the mother is a matter of concern. In order to obtain more knowledge about the distribution of ethyl paraben and butyl paraben in pregnant rats and pups after perinatal exposure, the presented study was designed. The data show response and distribution of ethyl paraben and butyl paraben in maternal rat plasma, pools of amniotic fluids, placenta, whole-body fetuses, and in fetal liver after dosing of dams with 100, 200, and 400 mg/kg body weight (bw)/day from gestational day 7 to 21. After cesarean section of dams, the fluids and tissues were collected, deconjugated, and purified by solid-phase extraction, and ethyl paraben and butyl paraben were analyzed by liquid chromatography-tandem mass spectrometry. Markedly higher levels of ethyl paraben compared to butyl paraben were found in all fluids and tissues. Both ethyl paraben and butyl paraben in maternal plasma, livers, and whole-body tissues from fetus seemed to be saturated after dosing with >or= 100 mg/kg bw/day, while both compounds were excreted into amniotic fluid in a dose-dependent manner. Significant difference was found between the level of ethyl paraben in maternal plasma and amniotic fluid after dosing with 200 mg/kg bw/day as well as between the levels of butyl paraben in maternal plasma and amniotic fluid after dosing with 100, 200, and 400 mg/kg bw/day.

  17. Isotope effects and the temperature dependences of the hyperfine coupling constants of muoniated sec-butyl radicals in condensed phases.

    Science.gov (United States)

    Fleming, Donald G; Bridges, Michael D; Arseneau, Donald J; Chen, Ya Kun; Wang, Yan Alexander

    2011-04-01

    Reported here is the first μSR study of the muon (A(μ)) and proton (A(p)) β-hyperfine coupling constants (Hfcc) of muoniated sec-butyl radicals, formed by muonium (Mu) addition to 1-butene and to cis- and trans-2-butene. The data are compared with in vacuo spin-unrestricted MP2 and hybrid DFT/B3YLP calculations reported in the previous paper (I), which played an important part in the interpretation of the data. The T-dependences of both the (reduced) muon, A(μ)′(T), and proton, A(p)(T), Hfcc are surprisingly well explained by a simple model, in which the calculated Hfcc from paper I at energy minima of 0 and near ±120° are thermally averaged, assuming an energy dependence given by a basic 2-fold torsional potential. Fitted torsional barriers to A(μ)′(T) from this model are similar (~3 kJ/mol) for all muoniated butyl radicals, suggesting that these are dominated by ZPE effects arising from the C−Mu bond, but for A(p)(T) exhibit wide variations depending on environment. For the cis- and trans-2-butyl radicals formed from 2-butene, A(μ)′(T) exhibits clear discontinuities at bulk butene melting points, evidence for molecular interactions enhancing these muon Hfcc in the environment of the solid state, similar to that found in earlier reports for muoniated tert-butyl. In contrast, for Mu−sec-butyl formed from 1-butene, there is no such discontinuity. The muon hfcc for the trans-2-butyl radical are seemingly very well predicted by B3LYP calculations in the solid phase, but for sec-butyl from 1-butene, showing the absence of further interactions, much better agreement is found with the MP2 calculations across the whole temperature range. Examples of large proton Hfcc near 0 K are also reported, due to eclipsed C−H bonds, in like manner to C−Mu, which then also exhibit clear discontinuities in A(p)(T) at bulk melting points. The data suggest that the good agreement found between theory and experiment from the B3LYP calculations for eclipsed bonds in

  18. Diisobutyl phthalate has comparable anti-androgenic effects to di-n-butyl phthalate in fetal rat testis

    DEFF Research Database (Denmark)

    Boberg, Julie; Petersen, Marta Axelstad; Vinggaard, Anne;

    2006-01-01

    Phthalates are widely used as plasticizers in various consumer products and building materials. Some of the phthalates are known to interfere with male reproductive development in rats, and di-n-butyl phthalate (DBP), diethylhexyl phthalate (DEHP) and butyl benzyl phthalate (BBP) were recently...... banned for use in toys in the EU mainly due to their reproductive toxicity. Diisobutyl phthalate (DiBP) has similar structural and application properties as DBP. and is being used as a substitute for DBR However, knowledge on male reproductive effects of DiBP in experimental animals is lacking, Methods...

  19. Quercetin protects human hepatoma HepG2 against oxidative stress induced by tert-butyl hydroperoxide.

    Science.gov (United States)

    Alía, Mario; Ramos, Sonia; Mateos, Raquel; Granado-Serrano, Ana Belén; Bravo, Laura; Goya, Luis

    2006-04-15

    Flavonols such as quercetin, have been reported to exhibit a wide range of biological activities related to their antioxidant capacity. The objective of the present study was to investigate the protective effect of quercetin on cell viability and redox status of cultured HepG2 cells submitted to oxidative stress induced by tert-butyl hydroperoxide. Concentrations of reduced glutathione and malondialdehyde, generation of reactive oxygen species and activity and gene expression of antioxidant enzymes were used as markers of cellular oxidative status. Pretreatment of HepG2 with 10 microM quercetin completely prevented lactate dehydrogenase leakage from the cells. Pretreatment for 2 or 20 h with all doses of quercetin (0.1-10 microM) prevented the decrease of reduced glutathione and the increase of malondialdehyde evoked by tert-butyl hydroperoxide in HepG2 cells. Reactive oxygen species generation induced by tert-butyl hydroperoxide was significantly reduced when cells were pretreated for 2 or 20 h with 10 microM and for 20 h with 5 microM quercetin. Finally, some of the quercetin treatments prevented the significant increase of glutathione peroxidase, superoxide dismutase, glutathione reductase and catalase activities induced by tert-butyl hydroperoxide. Gene expression of antioxidant enzymes was also affected by the treatment with the polyphenol. The results of the biomarkers analyzed clearly show that treatment of HepG2 cells in culture with the natural dietary antioxidant quercetin strongly protects the cells against an oxidative insult.

  20. Carbamoylcholine analogs as nicotinic acetylcholine receptor agonists--structural modifications of 3-(dimethylamino)butyl dimethylcarbamate (DMABC)

    DEFF Research Database (Denmark)

    Hansen, Camilla Petrycer; Jensen, Anders Asbjørn; Balle, Thomas;

    2009-01-01

    Compounds based on the 3-(dimethylamino)butyl dimethylcarbamate (DMABC) scaffold were synthesized and pharmacologically characterized at the alpha(4)beta(2), alpha(3)beta(4,) alpha(4)beta(4) and alpha(7) neuronal nicotinic acetylcholine receptors (nAChRs). The carbamate functionality and a small...

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

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    1995-01-01

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

  2. Synthesis and characterization of di- and triorganotin(IV) complexes of 2-tert-butyl-4-methyl phenol

    Indian Academy of Sciences (India)

    Neeraj Sharma; Archana; Maridula Thakur; S S Bhatt; S C Chaudhry

    2007-07-01

    The di- and trialkyltin(IV) complexes of composition R2SnCl2-(OAr), and -Bu3Sn(OAr) (R = -Bu and Me; = 1 and 2; OAr = OC6H3Bu-2-Me-4) have been synthesized by the reactions of di-n-butyl and dimethyltin dichlorides and tri-n-butyltin(IV) chloride with 2-tert-butyl-4-methylphenol and triethylamine in tetrahydrofuran. The reaction of triphenyltin chloride with trimethylsilyl-2-t-butyl-4-methylphenoxide in the same solvent however, gives a complex of composition Ph3Sn(OAr). The complexes have been characterized by microanalyses, molar conductance measurements, molecular weight determinations and IR and 1H, 13C and 119Sn NMR and mass spectral studies. Thermal behaviour of the complexes has been studied by TGA and DTA techniques. From the non-isothermal TG data, the kinetic and thermodynamic parameters have been calculated employing Coats-Redfern equation and the mechanism of decomposition has been computed using non-isothermal kinetic method. Thermal investigations on the blends of poly(methylmethacrylate). PMMA, with organotin(IV)-2-tert-butyl-4-methylphenoxides have shown increased thermal stability compared to pure PMMA suggesting thereby their potential as additives towards PMMA.

  3. Rapid and high yields of synthesis of butyl acetate catalyzed by Novozym 435 : Reaction optimization by response surface methodology

    NARCIS (Netherlands)

    Martins, Andrea B.; Graebin, Natalia G.; Soibelmann Glock Lorenzoni, André; Fernandez-Lafuente, Roberto; Ayub, Marco A. Z.; Rodrigues, Rafael C.

    2011-01-01

    In this paper is described the optimization of the esterification reaction of butyl acetate synthesis catalyzed by Candida antarctica lipase B (Novozym 435). The reaction parameters temperature, substrate molar ratio, enzyme content, and added water, and their responses measured as conversion yields

  4. Di-iso-Butyl Phthalate MATERNAL AND FETAL DATA FROM THE LE GRAY RESEARCH TEAM FOR NCEA June 15 2016

    Science.gov (United States)

    this file contains the raw data on the effects of in utero administration of di-iso-butyl phthalate on maternal weight gain during dosing and the numbers of fetuses and fetal resorptions. The data have all been previously published, as described on the file metadata sheet.

  5. Crystal structure of 2-tert-butyl-1,3-thiazolo[4,5-b]pyridine

    Directory of Open Access Journals (Sweden)

    Gamal A. El-Hiti

    2014-09-01

    Full Text Available The title compound, C10H12N2S, does not contain any strong hydrogen-bond donors but two long C—H...N contacts are observed in the crystal structure, with the most linear interaction linking molecules along [010]. The ellipsoids of the tert-butyl group indicate large librational motion.

  6. Effect of butylated hydroxytoluene, curcumin, propyl gallate and thiabendazole on cytochrome P450 forms in cultured human hepatocytes

    NARCIS (Netherlands)

    Price, R.J.; Scott, M.P.; Giddings, A.M.; Walters, D.G.; Stierum, R.H.; Meredith, C.; Lake, B.G.

    2008-01-01

    1. The objective of this study was to investigate the effects of four food chemicals, namely butylated hydroxytoluene (BHT), curcumin (CC), propyl gallate (PG) and thiabendazole (TB), on cytochrome P450 (CYP) forms in cultured human hepatocytes. 2. Treatment of human hepatocytes for 72 h with 2-200

  7. Densities and Kinematic Viscosities for the Systems Benzene + Methyl Formate, Benzene + Ethyl Formate, Benzene + Propyl Formate, and Benzene + Butyl Formate

    DEFF Research Database (Denmark)

    Emmerling, Uwe; Rasmussen, Peter

    1998-01-01

    Densities and kinematic viscosities have been measured for the system benzene + methyl formate at 20°C and for the systems benzene + ethyl formate, benzene + propyl formate, and benzene + butyl formate from 20°C to 50°C. The results for the system benzene + methyl formate have been correlated usi...

  8. Nonlinear viscoelastic response of carbon black-filled butyl rubber and implications for o-ring aging

    Energy Technology Data Exchange (ETDEWEB)

    Adolf, D.

    1997-11-01

    Butyl rubber, unfortunately, has pronounced nonlinear viscoelastic behavior, which may be modelled by a separable KBKZ formalism. While these effects seem to have minimal impact on accelerated sealing force measurements, they do severely impact compression set tests. Therefore, a new test is suggested for evaluating field-return o-rings which is free from such confounding effects.

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

    Science.gov (United States)

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

  10. Basic butylated methacrylate copolymer/kappa-carrageenan interpolyelectrolyte complex: preparation, characterization and drug release behaviour.

    Science.gov (United States)

    Prado, H J; Matulewicz, M C; Bonelli, P; Cukierman, A L

    2008-09-01

    The formation of a novel interpolyelectrolyte complex (IPEC) between basic butylated methacrylate copolymer and kappa-carrageenan was investigated and the product formed was characterized. Turbidity measurements and elemental analyses pointed to a 1:1 interaction of the repeating units. These results and FT-IR confirmed IPEC formation. Electronic microscopy images, particle size determination by image analysis and N(2) (77K) adsorption measurements were consistent with a porous material. This IPEC formed presented very good flowability and compactibility. Two maxima were observed in the swelling behaviour as a function of pH. The performance of the IPEC as a matrix for controlled release of drugs was evaluated, using ibuprofen as a model drug. Release profiles were properly represented by a mathematical model, which indicates that the system releases ibuprofen in a zero-order manner. These profiles could be controlled by conveniently modifying the proportion of the IPEC in the tablets.

  11. Effect of Counteranions on the Conformational Equilibrium of 1-Butyl-3-methylimidazolium-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Naohiro Hatano

    2011-01-01

    Full Text Available We have investigated the nonspherical anion effect on the trans-trans (TT and gauche-trans (GT equilibrium in pure 1-butyl-3-methylimidazolium ([bmim]+-based room temperature ionic liquids (RTILs by the Raman spectroscopy. The intensity ratio of the [bmim]+ cation in [bmim]+-based RTILs having nonspherical anions changes with nature of the anions. However, the enthalpy change of the [bmim]+ cation is approximately −1.0 kJ/mol for all [bmim]+-based RTILs used in this study and is independent of the anionic species. The present results indicate that the conformational stability of the [bmim]+ cation in [bmim]+-based RTILs including nonspherical anions is driven by the entropic contribution associated with the orientation and configuration of the [bmim]+ cation with respect to the counteranion.

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

    Science.gov (United States)

    Shamsudin, Intan Juliana; Ahmad, Azizan; Hassan, Nur Hasyareeda

    2014-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-03

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

  14. Electrochemical behavior of CoCl2 in ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhou; HE De-liang; CUI Zheng-dan; ZHONG Jian-fang; LI Guo-xi

    2008-01-01

    The electrochemical behavior of CoCl2 in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF6) was investigated by cyclic voltammetry. The cyclic voltammograms were obtained from electrochemical measurement under different temperatures, and the reversible behavior for Co2+/Co3+ redox couple on glassy carbon electrode in [bmim]PF6 was confirmed by the characteristic of the peak currents. The diffusion coefficients (about 10-11m2/s) of Co2+ in [bmim]PF6 under different temperatures were evaluated from the dependence of the peak current density on the potential scan rates in cyclic voltammograms. It is found that the diffusion coefficient increases with increasing temperature. Diffusion activation energy of Co2+ in [bmim]PF6 is also calculated to be 23.4kJ/mol according to the relationship between diffusion coefficient and temperature.

  15. Study on antibacterial dental resin using tri-n-butyl(4-vinylbenzyl)phosphonium chloride.

    Science.gov (United States)

    Kurata, Shigeaki; Hamada, Nobushiro; Kanazawa, Akihiko; Endo, Takeshi

    2011-01-01

    The antibacterial properties of a polymeric phosphonium salt were studied to determine its suitability as an additive to develop an antibacterial dental resin. The phosphonium salt monomer studied was tri-n-butyl(4-vinylbenzyl)phosphonium chloride (VP), and acrylic acid (AC) and methacryloyloxyethyl trimethyl ammonium chloride (MA) were used as controls. The antibacterial activity of these monomers and their corresponding polymers (PVP, PAC, and PMA) against Streptococcus mutans (S. mutans) was examined. When incubating S. mutans in a medium containing 10 μmol/mL for 24 hours, the antibacterial activity of PVP against S. mutans was high, while the antibacterial activity of PMA and VP was lower. AC, PAC and PMA exhibited the lowest antibacterial activity. The mechanical properties of the copolymers of methyl methacrylate, 2-hydroxyethyl methacrylate, and VP decreased as VP content increased, and were lower than those of poly(methyl methacrylate).

  16. (2-tert-Butyl-3-phenyl-2,3-dihydroisoxazole-4,5-diylbis(phenylmethanone

    Directory of Open Access Journals (Sweden)

    M. R. Prathapachandra Kurup

    2013-08-01

    Full Text Available The phenyl and tert-butyl groups of the title compound, C27H25NO3, exhibit a trans configuration in agreement with the stereochemistry of the Z phenyl-N-tert-butylnitrone starting material. The attached carbonyl groups are not coplanar with the neighboring dihydroisoxazole ring and the phenyl rings they are bonded to, with torsion angles of 59.26 (8, 17.53 (11, 16.52 (12 and 52.86 (7°. The dihedral angle between the dihydroisoxazole ring and the directly attached phenyl group is 86.86 (8°. There are two nonclassical intermolecular C—H...O hydrogen-bonding interactions that operate together with an intermolecular C—H...π interaction to form a supramolecular architecture in the crystal system.

  17. Barrierity of hydrogenated butadiene-acrylonitrile rubber and butyl rubber after exposure to organic solvents.

    Science.gov (United States)

    Krzemińska, Sylwia; Rzymski, Władysław M

    2011-01-01

    Resistance of antichemical clothing primarily depends on the type of material it is made from, in particular on the type of polymer used for coating the fabric carrier. This paper reports on systematic investigations on the influence of the cross-linking density of an elastomer and the composition of a cross-linked elastomer on its resistance to permeation of selected organic solvents. Tests of barrier material samples made from nonpolar butyl rubber (IIR) and polar hydrogenated butadiene-acrylonitrile rubber (HNBR) showed that (a) in rubber-solvent systems with medium thermodynamic affinity, cross-linking density influenced resistance to permeation and (b) the polarity of the system had a significant influence on barrierity.

  18. Effect of 1-butyl-3-methylimidazolium tetrafluoroborate on the formation rate of CO2 hydrate

    Institute of Scientific and Technical Information of China (English)

    Qi Chen; Yong Yu; Peng Zeng; Wei Yang; Qianqing Liang; Xiaoming Peng; Yansheng Liu; Yufeng Hu

    2008-01-01

    The effect of the addition of 1-butyl-3-methylimidazolium tetrafluoroborate([C4mim][BF4])on the formation rates of CO2 hydrates was investigate.The isothermal and isobaric methods were used to measure the formation rates of CO2 hydrates.As compared to those of pure water,the data of phase equilibrium changed greatly.The effects of pressure,temperature,and the concentration of [C4mim][BF4] aqueous solution on the formation rates of CO2 hydrates were investigated.With a constant concentration of[C4mim][BF4],the rate of gas consumption was enhanced with the lowering of experimental temperature.However,a decrease in pressure exerted an opposite effect on the rate of gas consumption.Moreover,the addition of[C4mim][BF4]raised the equilibrium pressure of hydrate formation at the same temperature.

  19. Analysis of Oxygenated Component (butyl Ether) and Egr Effect on a Diesel Engine

    Science.gov (United States)

    Choi, Seung-Hun; Oh, Young-Taig

    Potential possibility of the butyl ether (BE, oxygenates of di-ether group) was analyzed as an additives for a naturally aspirated direct injection diesel engine fuel. Engine performance and exhaust emission characteristics were analyzed by applying the commercial diesel fuel and oxygenates additives blended diesel fuels. Smoke emission decreased approximately 26% by applying the blended fuel (diesel fuel 80 vol-% + BE 20vol-%) at the engine speed of 25,000 rpm and with full engine load compared to the diesel fuel. There was none significant difference between the blended fuel and the diesel fuel on the power, torque, and brake specific energy consumption rate of the diesel engine. But, NOx emission from the blended fuel was higher than the commercial diesel fuel. As a counter plan, the EGR method was employed to reduce the NOx. Simultaneous reduction of the smoke and the NOx emission from the diesel engine was achieved by applying the BE blended fuel and the cooled EGR method.

  20. Butyl rubber O-ring seals: Revision of test procedures for stockpile materials

    Energy Technology Data Exchange (ETDEWEB)

    Domeier, L.A.; Wagter, K.R.

    1996-12-01

    Extensive testing showed little correlation between test slab and O-ring performance. New procedures, comparable to those used with the traditional test slabs, were defined for hardness, compression set, and tensile property testing on sacrificial O-ring specimens. Changes in target performance values were made as needed and were, in one case, tightened to reflect the O-ring performance data. An additional study was carried out on O-ring and slab performance vs cure cycle and showed little sensitivity of material performance to large changes in curing time. Aging and spectra of certain materials indicated that two sets of test slabs from current vendor were accidently made from EPDM rather than butyl rubber. Random testing found no O-rings made from EPDM. As a result, and additional spectroscope test will be added to the product acceptance procedures to verify the type of rubber compound used.

  1. Liquid-Liquid equilibria of the water-acetic acid-butyl acetate system

    Directory of Open Access Journals (Sweden)

    E. Ince

    2002-04-01

    Full Text Available Experimental liquid-liquid equilibria of the water-acetic acid-butyl acetate system were studied at temperatures of 298.15± 0.20, 303.15± 0.20 and 308.15± 0.20 K. Complete phase diagrams were obtained by determining solubility and tie-line data. The reliability of the experimental tie-line data was ascertained by using the Othmer and Tobias correlation. The UNIFAC group contribution method was used to predict the observed ternary liquid-liquid equilibrium (LLE data. It was found that UNIFAC group interaction parameters used for LLE did not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region.

  2. Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system

    Energy Technology Data Exchange (ETDEWEB)

    Chen Liang [College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)], E-mail: doseng_1982@hotmail.com; Xu Lingling; Shang Hongbo; Zhang Zhibin [College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2009-03-15

    For the last 20 years, microencapsulated phase change materials (MicroPCMs), which combine microencapsulation technology and phase change material, have been attracted more and more interest. By overcoming some limitations of the PCMs, the MicroPCMs improve the efficiency of PCMs and make it possible to apply PCMs in many areas. In this experiment, polyurea microcapsules containing phase change materials were prepared using interfacial polycondensation method. Toluene-2,4-diisocyanate (TDI) and ethylenediamine (EDA) were chosen as monomers. Butyl stearate was employed as a core material. The MicroPCMs' properties have been characterized by dry weight analysis, differential scanning calorimetry, Fourier transform IR spectra analysis and optical microscopy. The results show that the MicroPCMs were synthesized successfully and that, the phase change temperature was about 29 deg. C, the latent heat of fusion was about 80 J g{sup -1}, the particle diameter was 20-35 {mu}m.

  3. Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chen; Lingling, Xu; Hongbo, Shang; Zhibin, Zhang [College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2009-03-15

    For the last 20 years, microencapsulated phase change materials (MicroPCMs), which combine microencapsulation technology and phase change material, have been attracted more and more interest. By overcoming some limitations of the PCMs, the MicroPCMs improve the efficiency of PCMs and make it possible to apply PCMs in many areas. In this experiment, polyurea microcapsules containing phase change materials were prepared using interfacial polycondensation method. Toluene-2,4-diisocyanate (TDI) and ethylenediamine (EDA) were chosen as monomers. Butyl stearate was employed as a core material. The MicroPCMs' properties have been characterized by dry weight analysis, differential scanning calorimetry, Fourier transform IR spectra analysis and optical microscopy. The results show that the MicroPCMs were synthesized successfully and that, the phase change temperature was about 29 C, the latent heat of fusion was about 80 J g{sup -1}, the particle diameter was 20-35 {mu}m. (author)

  4. Transdermal uptake of diethyl phthalate and di(n-butyl) phthalate directly from air: Experimental verification

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Bekö, Gabriel; Koch, Holger M.;

    2015-01-01

    Background: Fundamental considerations indicate that, for certain phthalate esters, dermal absorption from air is an uptake pathway that is comparable to or greater than inhalation. Yet this pathway has not been experimentally evaluated and has been largely overlooked when assessing uptake...... of phthalate esters. Objectives: This study investigated transdermal uptake, directly from air, of diethyl phthalate (DEP) and di(n-butyl) phthalate (DnBP) in humans. Methods: In a series of experiments, six human participants were exposed for 6 hr in a chamber containing deliberately elevated air...... concentrations of DEP and DnBP. The participants either wore a hood and breathed air with phthalate concentrations substantially below those in the chamber or did not wear a hood and breathed chamber air. All urinations were collected from initiation of exposure until 54 hr later. Metabolites of DEP and Dn...

  5. Study of n-Butyl Acrylate Self-Initiation Reaction Experimentally and via Macroscopic Mechanistic Modeling

    Directory of Open Access Journals (Sweden)

    Ahmad Arabi Shamsabadi

    2016-04-01

    Full Text Available This paper presents an experimental study of the self-initiation reaction of n-butyl acrylate (n-BA in free-radical polymerization. For the first time, the frequency factor and activation energy of the monomer self-initiation reaction are estimated from measurements of n-BA conversion in free-radical homo-polymerization initiated only by the monomer. The estimation was carried out using a macroscopic mechanistic mathematical model of the reactor. In addition to already-known reactions that contribute to the polymerization, the model considers a n-BA self-initiation reaction mechanism that is based on our previous electronic-level first-principles theoretical study of the self-initiation reaction. Reaction rate equations are derived using the method of moments. The reaction-rate parameter estimates obtained from conversion measurements agree well with estimates obtained via our purely-theoretical quantum chemical calculations.

  6. Inhibition Effect of 1-Butyl-4-Methylpyridinium Tetrafluoroborate on the Corrosion of Copper in Phosphate Solutions

    Directory of Open Access Journals (Sweden)

    M. Scendo

    2011-01-01

    Full Text Available The influence of the concentration of 1-Butyl-4-methylpyridinium tetrafluoroborate (4MBPBF4 as ionic liquid (IL on the corrosion of copper in 0.5 M PO43− solutions of pH 2 and 4 was studied. The research involved electrochemical polarization method, and scanning electron microscopy (SEM technique. The results obtained showed that the inhibition efficiency of corrosion of copper increases with an increase in the concentration of 4MBPBF4 but decreases with increasing temperature. The thermodynamic functions of corrosion analysis and adsorptive behavior of 4MBPBF4 were carried out. During the test, the adsorption of the inhibitor on the copper surface in the phosphate solutions was found to obey the Langmuir adsorption isotherm and had a physical mechanism.

  7. Linear Viscoelasticity of Spherical SiO 2 Nanoparticle-Tethered Poly(butyl acrylate) Hybrids

    KAUST Repository

    Goel, Vivek

    2010-12-01

    The melt state linear viscoelastic properties of spherical silica nanoparticles with grafted poly(n-butyl acrylate) chains of varying molecular weight were probed using linear small amplitude dynamic oscillatory measurements and complementary linear stress relaxation measurements. While the pure silica-tethered-polymer hybrids with no added homopolymer exhibit solid-like response, addition of matched molecular weight free matrix homopolymer chains to this hybrid, at low concentrations of added homopolymer, maintains the solid-like response with a lowered modulus that can be factored into a silica concentration dependence and a molecular weight dependence. While the silica concentration dependence of the modulus is strong, the dependence on molecular weight is weak. On the other hand, increasing the amount of added homopolymer changes the viscoelastic response to that of a liquid with a relaxation time that scales exponentially with hybrid concentration. © 2010 American Chemical Society.

  8. Tribological performance and chemistry of films for di-n-butyl dithiocarbamate derivatives in rapeseed oil

    Institute of Scientific and Technical Information of China (English)

    WU Hua; ZENG XiangQiong; LU LingBo; REN TianHui

    2007-01-01

    Two di-n-butyl dithiocarbamate derivatives were easily synthesized. Their tribological performances as lubricating oil additives in rapeseed oil were evaluated using a four-ball machine, and their chemistry of films was analyzed with X-ray absorption near-edge spectroscopy (XANES). The results indicate that the two compounds possess excellent anti-wear property and good load-carrying capacity. According to the XANES results, for the thermal films, the outer surfaces are mainly composed of N, S-containing polymer and ferric sulfate, and the near-surface and the bulk are composed of ferrous sulfate, while for the anti-wear films, the outer surfaces are only composed of ferric sulfate, but the near-surface and the bulk are mainly composed of ferrous sulfate.

  9. Monomer reactivity ratios for fluoroacrylate and butyl methacrylate in miniemulsion copolymerizations initiated by potassium persulphate

    Institute of Scientific and Technical Information of China (English)

    Qing Hua Zhang; Zhen Huan Luo; Xiao Li Zhan; Feng Qiu Chen

    2009-01-01

    Miniemulsion copolymerization of butyl mathacrylate(BMA)with fluoroacrylate(HFMA,TFMA)was carded out at 70℃ by employing potassium persulphate(KPS)as initiator.Copolymer compositions at low conversion levels were determined by 1H NMR spectra techniques.The reactivity ratios were evaluated by employing Kellen-Tudos(K-T)methods,which yields the apparent reactivity ratios,rBMA=0.74,rHFMA=0.87 and rBMA=0.73,rTFMA=0.75,respectively,and Q-and e-values of HFMA and TFMA were calculated by the Alfrey-Price method.The results show that HFMA and TFMA are more active than BMA,and the cross-propagation rate constant is greater than the self-propagation one in these two copolymerizations.

  10. Poly[tetra-butyl-tetra-kis-(μ(2)-hydrogen phenyl-phospho-nato)ditin(IV)].

    Science.gov (United States)

    Sarr, Modou; Diasse-Sarr, Aminata; Diop, Libasse; Molloy, Kieran C; Kociok-Kohn, Gabriele

    2012-11-01

    In the title compound, [Sn(2)(C(4)H(9))(4)(C(6)H(6)PO(3))(4)](n), the basic unit is a dimer containing two symmetry-related Sn(IV) atoms bridged by two hydrogenphenylphosphonate anions. This fragment is located about an inversion center, and each Sn(IV) atom is linked to two other hydrogenphenylphosphonate anions, giving a layered structure parallel to (010). The coordination geometry for the Sn(IV) atoms is close to octa-hedral. The layers are connected via O-H⋯O hydrogen bonds, generating a three-dimensional network. One butyl group is disordered over two sets of sites, with occupancies of 0.49 (2) and 0.51 (2).

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

    Directory of Open Access Journals (Sweden)

    A Nikpey

    2006-07-01

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

  12. Structure-activity relationships for insect growth regulators derived from substituted di-tert-butyl phenols

    Energy Technology Data Exchange (ETDEWEB)

    Walton, B.T.; Sanborn, J.R.; Metcalf, R.L.

    1979-01-01

    Thirty-six para-substituted derivatives of 2,6-di-tert-butyl phenols were synthesized and tested for toxicity to fourth instar larvae of the mosquito Culex quinquefasciatus Say. Toxicities of these compounds ranged from an LC/sub 50/ of 0.004 ppM to LC/sub 50/ > 10 ppM. Mosquitoes treated with toxic analogues characteristically died shortly after the pupal molt and appeared to be morphologically normal, untanned pupae. Correlations of insecticidal activity with physicochemical parameters of the para-substituent was found to explain 71.82% of the variation in insecticidal activity expressed as log LC/sub 50/(mM).

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

    Directory of Open Access Journals (Sweden)

    Azadeh Asadi

    2006-01-01

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

  14. Modeling the temperature dependence of N-methylpyrrolidone permeation through butyl- and natural-rubber gloves.

    Science.gov (United States)

    Zellers, E T; Sulewski, R

    1993-09-01

    This paper describes the temperature dependence of N-methylpyrrolidone (NMP) permeation through gloves used in microelectronics fabrication facilities. One type of butyl-rubber glove (North B161), two types of natural-rubber gloves (Edmont Puretek and Ansell Pacific White), and a natural rubber/nitrile/neoprene-blend glove (Pioneer Trionic) were tested at four temperatures from 25-50 degrees C using the ASTM F739-85 permeation test method. The butyl-rubber glove showed no breakthrough after four hours of exposure at any temperature. The variations with temperature of measured breakthrough times (BT) and steady-state permeation rates (SSPR) for the other gloves were described well by Arrhenius relationships, with BT values decreasing by factors of 7-10 and SSPR values increasing by factors of 4-6 over the temperature range studied. Extrapolation to 70 and 93 degrees C, the temperatures at which degreasing is often performed, yielded BT values of rubber glove, following an initial exposure at 25 degrees C and air drying overnight, low levels of NMP vapor were detected off-gassing from the inner surfaces of the gloves. Experimental results were then compared to those expected from several permeation models. Estimates of the equilibrium solvent solubility, S, were calculated using a model based on three-dimensional solubility parameters. Estimates of the solvent diffusion coefficient, D, were obtained from correlations with either the solvent kinematic viscosity or the product of the Flory interaction parameter, chi, and the solvent molar volume. Combining these values of D and S in Fickian diffusion equations gave modeled BT estimates that were within 23% of experimental values over the temperature range examined. Modeled SSPR values were within 50% (typically within 25%) of experimental values. Another model based on a generalized Arrhenius relationship also provided useful but generally less accurate estimates of the changes in BT and SSPR values with temperature.

  15. The mechanism of catalytic methylation of 2-phenylpyridine using di-tert-butyl peroxide.

    Science.gov (United States)

    Sharma, Akhilesh K; Roy, Dipankar; Sunoj, Raghavan B

    2014-07-14

    The mechanism of palladium chloride-catalyzed direct methylation of arenes with peroxides is elucidated by using the energetics computed at the M06 density functional theory. The introduction of a methyl group by tert-butyl peroxides at the ortho-position of a prototypical 2-phenyl pyridine, a commonly used substrate in directed C-H functionalization reactions, is examined in detail by identifying the key intermediates and transition states involved in the reaction sequence. Different possibilities that differ in terms of the site of catalyst coordination with the substrate and the ensuing mechanism are presented. The important mechanistic events involved are (a) an oxidative or a homolytic cleavage of the peroxide O-O bond, (b) C-H bond activation, (c) C-C bond activation, and (d) reductive elimination involving methyl transfer to the aromatic ring. We have examined both radical and non-radical pathways. In the non-radical pathway, the lowest energy pathway involves C-H bond activation prior to the coordination of the peroxide to palladium, which is subsequently followed by the O-O bond cleavage of the peroxide and the C-C bond activation. Reductive elimination in the resulting intermediate leads to the vital C-C bond formation between methyl and aryl carbon atoms. In the non-radical pathway, the C-C bond activation is higher in energy and has been identified as the rate-limiting step of this reaction. In the radical pathway, however, the activation barrier for the C-C bond cleavage is lower than for the peroxide O-O bond cleavage. A combination of a radical pathway up to the formation of a palladium methyl intermediate and a subsequent non-radical pathway has been identified as the most favored pathway for the title reaction. The predicted mechanism is in good agreement with the experimental observations on PdCl2 catalyzed methylation of 2-phenyl pyridine using tert-butyl peroxide.

  16. Ethyl t-butyl ether: review of reproductive and developmental toxicity.

    Science.gov (United States)

    de Peyster, Ann

    2010-06-01

    Ethyl t-butyl ether (ETBE) is a motor fuel oxygenate used in reformulated gasoline. Knowledge of developmental and reproductive toxicity potential of ETBE is critical for making informed decisions about acceptance and regulations. This review discusses toxicology studies providing information about effects on reproduction and the conceptus. Seven GLP-compliant studies following widely accepted protocols have focused specifically on developmental and reproductive toxicity (DART) in rats and rabbits exposed to ETBE by gavage with doses up to 1,000 mg/kg body weight/day, the limit specified in standardized test guidelines. Other repeat-dose general toxicology studies have administered ETBE to rodents for up to 180 days, and included reproductive organ weights, histology, or other indications of reproductive system structure or function. DART potential of the main ETBE metabolite t-butyl alcohol and class-related MTBE has also been studied. More GLP-compliant studies exist for evaluating ETBE using well-established, currently recommended protocols than are available for many other chemicals used today. The database for determining ETBE DART potential is adequate, although not all study details are currently easily accessible for peer-review. ETBE does not appear to be selectively toxic to reproduction or embryofetal development in the absence of other manifestations of general toxicity. Studies using recommended methods for sample preservation and analysis have shown no targeted effect on the reproductive system. No embryofetal effects were observed in rabbits. Early postnatal rat pup deaths show no clear dose-response and have largely been attributed to total litter losses with accompanying evidence of maternal neglect or frank maternal morbidity.

  17. Subchronic exposure to ethyl tertiary butyl ether resulting in genetic damage in Aldh2 knockout mice.

    Science.gov (United States)

    Weng, Zuquan; Suda, Megumi; Ohtani, Katsumi; Mei, Nan; Kawamoto, Toshihiro; Nakajima, Tamie; Wang, Rui-Sheng

    2013-09-15

    Ethyl tertiary butyl ether (ETBE) is biofuel additive recently used in Japan and some other countries. Limited evidence shows that ETBE has low toxicity. Acetaldehyde (AA), however, as one primary metabolite of ETBE, is clearly genotoxic and has been considered to be a potential carcinogen. The aim of this study was to evaluate the effects of ALDH2 gene on ETBE-induced genotoxicity and metabolism of its metabolites after inhalation exposure to ETBE. A group of wild-type (WT) and Aldh2 knockout (KO) C57BL/6 mice were exposed to 500ppm ETBE for 1-6h, and the blood concentrations of ETBE metabolites, including AA, tert-butyl alcohol and 2-methyl-1,2-propanediol, were measured. Another group of mice of WT and KO were exposed to 0, 500, 1750, or 5000ppm ETBE for 6h/day with 5 days per weeks for 13 weeks. Genotoxic effects of ETBE in these mice were measured by the alkaline comet assay, 8-hydroxyguanine DNA-glycosylase modified comet assay and micronucleus test. With short-term exposure to ETBE, the blood concentrations of all the three metabolites in KO mice were significantly higher than the corresponding concentrations of those in WT mice of both sexes. After subchronic exposure to ETBE, there was significant increase in DNA damage in a dose-dependent manner in KO male mice, while only 5000ppm exposure significantly increased DNA damage in male WT mice. Overall, there was a significant sex difference in genetic damage in both genetic types of mice. These results showed that ALDH2 is involved in the detoxification of ETBE and lack of enzyme activity may greatly increase the sensitivity to the genotoxic effects of ETBE, and male mice were more sensitive than females.

  18. Combined prenatal and postnatal butyl paraben exposure produces autism-like symptoms in offspring: comparison with valproic acid autistic model.

    Science.gov (United States)

    Ali, Elham H A; Elgoly, Amany H Mahmoud

    2013-10-01

    The aim of this work is to evaluate the impact of butyl paraben (BP) in brain of the pups developed for mothers administered BP from early pregnancy till weaning and its effect on studying the behavior, brain neurotransmitters and brain derived neurotrophic factor BDNF via comparing the results with valproic acid (VA) autistic-rat model preparing by a single oral injection dose of VA (800 mg/kg b.wt) at the 12.5 days of gestation. Butyl paraben was orally and subcutaneously administered (200 mg/kg b.wt) to pregnant rats from gestation day 1 to lactation day 21. The offspring male rats were subjected at the last 3 days of lactation to Morris water maze and three chamber sociability test then decapitated and the brain was excised and dissected to the cortex, hippocampus, cerebellum, midbrain and pons for the determination of norepinephrine, dopamine and serotonin (NE, DA and 5-HT) and cortex amino acids and whole brain BDNF. The results showed similar social and learning and memory behavioral deficits in VA rat model and the butyl paraben offspring in comparison with the controls. Also, some similar alterations were observed in monoamine content, amino acids and BDNF factor in the autistic-like model and butyl paraben offspring in comparison with the controls. The alterations were recorded notably in hippocampus and pons NE, midbrain DA, hippocampus and midbrain 5-HT, and frontal cortex GABA and asparagine. These data suggest that prenatal exposure to butyl paraben induced neuro-developmental disorders similar to some of the neurodevelopmental disorders observed in the VA model of autism.

  19. HYOSCINE BUTYL BROMIDE VERSUS DROTAVERINE HYDROCHLORIDE IN ACTIVE STAGE OF LABOUR-A COMPARATIVE STUDY OF RATE OF CERVICAL DILATATION

    Directory of Open Access Journals (Sweden)

    Misha Pepsi

    2014-05-01

    Full Text Available AIM: This study was conducted to compare the rate of cervical dilatation with hyoscine butyl bromide and drotaverine hydrochloride in active stage of labour. MATERIALS AND METHODOLOGY: This prospective study was conducted in the department of Obstetrics and Gynaecology. Inclusion Criteria: 1. All women with initial cervical dilatation of 3 cms. 2. When there is a slow rate of cervical dilatation of less than 1.5 cms per hour or decent of less than 1 cm per hour for nulliparous and if dilatation was less than 2cms per hour for a multigravida. 3. And all singleton and cephalic pregnancies were included in this study. Exclusion Criteria included complications like Antepartum haemorrhage, Breech, C.P.D. In this study 400 women were allocated into two groups to receive either Hyoscine butyl bromide or Drotaverine hydrochloride. Two hours after admission in the active stage of labour, progress of labour was reassessed. If the progress of labour was satisfactory, then the wait and watch policy was adopted. If there was no progress they were administered one of the two drugs. 200 patients were administered 10mg of hyoscine butyl bromide suppositories rectally, (GROUP-1 AND THE OTHER 200 WITH 40mg of drotaverine hydrochloride intravenously (GROUP-2. The progress of labour was monitored by the partogram. Not more than 3 doses of hyoscine butyl bromide were administered. RESULTS: The rate of cervical dilatation was 2 cms per hour in group 1 (Hyoscine butyl bromide as compared to 1cm per hour in group 2 (Drotaverine hydrochloride. The difference in rate of cervical dilatation in both the groups was statistically significant. CONCLUSION: There was significant improvement in the rate of cervical dilatation with Hyoscine butyl bromide group of patients. There was a significant reduction in the duration of active stage of labour, and there was no significant second and third stage complication when these drugs were used. No untoward side effects were noted when

  20. Study of glue extrusion after endoscopic N-butyl-2-cyanoacrylate injection on gastric variceal bleeding

    Institute of Scientific and Technical Information of China (English)

    Yan-Mei Wang; Liu-Fang Cheng; Nan Li; Kai Wu; Jun-Shan Zhai; Ya-Wen Wang

    2009-01-01

    AIM: To investigate glue extrusion after endoscopic N-butyl-2-cyanoacrylate injection on gastric variceal bleeding and to evaluate the long-term efficacy and safety of this therapy.METHODS: A total of 148 cirrhotic patients in our hospital with esophagogastric variceal bleeding (EGVB) were included in this study. N-butyl-2-cyanoacrylate was mixed with lipiodol in a 1:1 ratio and injected as a bolus of 1-3 mL according to variceal size. Patients underwent endoscopic follow-up the next week, fourth week, second month, fourth month, and seventh month after injection and then every 6 mo to determine the cast shape. An abdominal X-ray film and ultrasound or computed tomographic scan were also carried out in order to evaluate the time of variceal disappearance and complete extrusion of the cast. The average follow-up time was 13.1 mo.RESULTS: The instantaneous hemostatic rate was 96.2%. Early re-bleeding after injection in 9 cases (6.2%) was estimated from rejection of adhesive. Late re-bleeding occurred in 12 patients (8.1%) at 2-18 mo. The glue cast was extruded into the lumen within one month in 86.1% of patients and eliminated within one year. Light erosion was seen at the injection position and mucosa edema in the second week. The glue casts were extruded in 18 patients (12.1%) after one week and in 64 patients (42.8%) after two weeks. All kinds of glue clumping shapes and colors on endoscopic examination were observed in 127 patients (86.1%) within one month, including punctiform, globular, pillar and variform. Forty one patients (27.9%) had glue extrusion after 3 mo and 28 patients (28.9%) after six months. The extrusion time was not related to the injection volume of histoacryl. Obliteration was seen in 70.2% (104 cases) endoscopically. The main complication was re-bleeding resulting from extrusion. The prognosis of the patients depended on the severity of the underlying liver disease.CONCLUSION: Endoscopic injection of cyanoacrylate is highly effective for

  1. Carboxylesterase-involved metabolism of di-n-butyl phthalate in pumpkin (Cucurbita moschata) seedlings.

    Science.gov (United States)

    Lin, Qingqi; Chen, Siyuan; Chao, Yuanqing; Huang, Xiongfei; Wang, Shizhong; Qiu, Rongliang

    2017-01-01

    Uptake and accumulation by plants is a significant pathway in the migration and transformation of phthalate esters (PAEs) in the environment. However, limited information is available on the mechanisms of PAE metabolism in plants. Here, we investigated the metabolism of di-n-butyl phthalate (DnBP), one of the most frequently detected PAEs, in pumpkin (Cucurbita moschata) seedlings via a series of hydroponic experiments with an initial concentration of 10 mg L(-1). DnBP hydrolysis occurred primarily in the root, and two of its metabolites, mono-n-butyl phthalate (MnBP) and phthalic acid (PA), were detected in all plant tissues. The MnBP concentration was an order of magnitude higher than that of PA in shoots, which indicated MnBP was more readily transported to the shoot than was PA because of the former's dual hydrophilic and lipophilic characteristics. More than 80% of MnBP and PA were located in the cell water-soluble component except that 96% of MnBP was distributed into the two solid cellular fractions (i.e., cell wall and organelles) at 96 h. A 13-20% and 29-54% increase of carboxylesterase (CXE) activity shown in time-dependent and concentration-dependent experiments, respectively, indicated the involvement of CXEs in plant metabolism of DnBP. The level of CXE activity in root subcellular fractions was in the order: the cell water-soluble component (88-94%) > cell wall (3-7%) > cell organelles (3-4%), suggesting that the cell water-soluble component is the dominant locus of CXE activity and also the domain of CXE-catalyzed hydrolysis of DnBP. The addition of triphenyl phosphate, a CXE inhibitor, led to 43-56% inhibition of CXE activity and 16-25% increase of DnBP content, which demonstrated the involvement of CXEs in plant metabolism of DnBP. This study contributes to our understanding of enzymitic mechanisms of PAE transformation in plants.

  2. Effect of Mixed Solvent on Fabrication, Morphology and Monodispersity of Microspheres with Hydrophobic Poly(butyl methacrylate) Shells

    Institute of Scientific and Technical Information of China (English)

    XIAO Xincai; LU Cheng

    2012-01-01

    Monodisperse microspheres (mean diameter 200-300 nm) with polystyrene cores and poly(acrylamide-co-buty1 methacrylate) shells were prepared by using a free radical polymerization method.Moreover,the effect of mixed solvent on the preparation,morphology and monodispersity was investigated.The experimental results showed that solubility parameter of butyl methacrylate and solvent affected mainly the molding of monodisperse core-shell microspheres.When the microspheres were fabricated in a sequential synthesis process,addition of hydrophilic and organic solvent including butyl methacrylate led to spherical degree of the particles becoming worse,and the mean diameter of the microspheres decreased and the monodispersity became better with increasing the crosslinker methylenebisacrylamide dosage.

  3. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetramethoxycalix[4]arene dichloromethane hemisolvate

    Directory of Open Access Journals (Sweden)

    Edwin Weber

    2008-04-01

    Full Text Available In the title compound, C48H64O4·0.5CH2Cl2, both crystallographically independent calixarene molecules display a partial cone conformation. Their crystal packing is stabilized by C—H...π contacts involving the methoxy groups. The solvent molecule is located interstitially between two calixarene units with C—H...Cl contacts to methoxy and tert-butyl groups. One tert-butyl residue of each calixarene molecule is disordered over two positions (occupancies 0.60/0.40 and 0.63/0.37, resulting in bond distances that deviate from ideal values. The tetramer calixarene molecules present models with approximate non-crystallographic Cs symmetry.

  4. Synthesis of 1-/sup 11/C-labelled ethyl, propyl, butyl and isobutyl iodides and examples of alkylation reactions

    Energy Technology Data Exchange (ETDEWEB)

    Laangstroem, B.; Antoni, G.; Gullberg, P.; Halldin, C.; Naagren, K.; Rimland, A.; Svaerd, H.

    1986-01-01

    New /sup 11/C-labelled precursors (1-/sup 11/C)ethyl,(1-/sup 11/C)propyl, (1-/sup 11/C)butyl, and (1-/sup 11/C)isobutyl iodides have been prepared by a 3-step reaction route using a one-pot system. The labelled iodides were obtained in 20-55% radiochemical yields and 65-95% radiochemical purities, with a total time for synthesis of the order of 10-14 min. The labelled iodides have been used in alkylation reactions with nitrogen, oxygen and carbon nucleophiles. The nitrogen alkylation reactions are exemplified by the synthesis of the analgetics N-(1-/sup 11/C-ethyl)iodocaine and N-(1-/sup 11/C-butyl) bupivacaine. The synthesis of 3-nitrophenyl(1-/sup 11/C)propyl ether is also presented in this paper as an example of an oxygen alkylation.

  5. Optimizing the Synthesis of Ethyl tert-Butyl Ether in Continuous Catalytic Distillation Column Using New Ion Exchange Resin Catalyst

    Institute of Scientific and Technical Information of China (English)

    Muhammad Umar; Yahia Abubakar Al-Hamed; Abdulraheem Al-Zahrani; Hisham Saeed Bamufleh

    2013-01-01

    Liquid phase synthesis of one of the important fuel oxygenate, ethyl tert-butyl ether (ETBE), from etha-nol and tert-butyl alcohol (TBA) has been studied in catalytic distillation column (CDC) using ion exchange resin catalyst CT-145H. A packed CDC of 1.2 m height and 50 mm diameter with indigenously developed reactive sec-tion packing was used to generate experimental data. Effect of different key variables on product purity in distillate, was investigated to find the optimum operating conditions for ETBE synthesis. The optimum conditions for 0.2 kg·s-1 of ethanol feed were found:reboiler duty of 375 W, molar feed ratio of 1︰1.3 of reactants, and reflux ratio of 7. Concentration profiles for each component along each column section at optimum conditions were also drawn. Neither output nor input multiplicity was observed at experimental conditions.

  6. Preparation and application of acidified/calcined red mud catalyst for catalytic degradation of butyl xanthate in Fenton-like process.

    Science.gov (United States)

    Shao, Luhua; Wei, Guangtao; Wang, Yizhi; Li, Zhongmin; Zhang, Linye; Zhao, Shukai; Zhou, Ming

    2016-08-01

    Acidified/calcined red mud (ACRM), a novel catalyst used in Fenton-like process, was prepared by acidification and calcination of red mud (RM). Catalyst characterization showed that iron phase of ACRM was mainly α-Fe2O3 and ACRM was a porous material with rough surface and loose structure. Degradation of butyl xanthate in Fenton-like process catalyzed by ACRM was investigated. Butyl xanthate was effectively degraded, and the degradation of butyl xanthate was well fitted by second order kinetic model. ACRM had an excellent long-term stability in a Fenton-like process. The possible mechanisms of hydroxyl radical production and butyl xanthate degradation in a Fenton-like process catalyzed by ACRM were presented.

  7. Experimental Measurements and Correlations Isobaric Vapor-Liquid Equilibria for Water + Acetic Acid + Sec-butyl Acetate at 101.3 kPa

    Institute of Scientific and Technical Information of China (English)

    LI Ling; HE Yong; WU Yanxiang; ZOU Wenhu

    2013-01-01

    Isobaric vapor-liquid equilibrium(VLE) data for acetic acid + sec-butyl acetate and water + acetic acid + sec-butyl acetate systems were determined at 101.3 kPa using a modified Rose type.The nonideality of the vapor phase caused by the association of the acetic acid was corrected by the chemical theory and Hayden-O'Connell method.Thermodynamic consistency was tested for the binary VLE data.The experimental data were correlated successfully with the Non-Random Two Liquids (NRTL) model.The Root Mean Square Deviation (RMSD) of the ternary system was 0.0038.The saturation vapor pressure of sec-butyl acetate at 329 to 385 K was measured by means of two connected equilibrium cells.The vapor pressures of water and sec-butyl acetate were correlated with the Antoine equation.The binary interaction parameters and the ternary VLE data were obtained from this work.

  8. Epoxidation and oxidation reactions using 1,4-butanediol dimethacrylate crosslinked polystyrene-supported tertiary butyl hydroperoxide

    Indian Academy of Sciences (India)

    M S Sheela; K Sreekumar

    2004-11-01

    1,4-Butanediol dimethacrylate (1,4-BDDMA) crosslinked polystyrene-supported -butyl hydroperoxide was employed in the epoxidation of olefins and oxidation of alcohols to carbonyl compounds. The reagent proved to be successful as a recyclable solid phase organic reagent with as much or more efficiency when compared to its monomeric counterpart. The extent of reaction was found to be dependent on various reaction parameters like solvent, temperature, molar concentration and presence of catalyst.

  9. Novel synthesis of 2-butyl-5chloro-3H-imidazole-4-carbaldehyde:A key intermediate of Losartan

    Institute of Scientific and Technical Information of China (English)

    Hai Bo Sun; Guo Jun Zheng; Ya Ping Wang; Xiang Jing Wang; Wen Sheng Xiang

    2009-01-01

    A novel method for synthesis of 2-butyl-5-chloro-3H-imidazole-4-carbaldehyde 2, a key intermediate of Losartan was reported. The compound 2 was synthesized from starting material dimethyl malonate 6 and n-valeronitrile 8 by six steps with an overall yield of 40%.The key step including the reaction of compound $ with POCI3/DMF followed by hydrolysis to give compound 2 with the yield of 68%.

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

    OpenAIRE

    Gholam H.S. Bonjar

    2005-01-01

    Fuel oxygenates are added to gasoline to enhance combustion efficiency of automobiles and reduce air pollution. Methyl tert-butyl ether (MTBE) is the most commonly used oxygenate because of its low cost, high-octane level and ease of blending with gasoline. However, due to its water solubility, high mobility and low biodegradability it leaches in soil subsurface at the speed of groundwater. Amending gasoline with MTBE has made a widespread contamination of groundwater, surface waters in coast...

  11. The synergic extraction of uranium (Ⅵ) with tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO)/benzene

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The synergistic extraction of uranium (Ⅵ) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum synergistic extraction effect occurs where the molar ratio of PSO to TBP is one to two. The composition of the complex of synergistic extraction is UO2(NO3)2.TB P.PSO. The formation constant of the complex KTp=57.44.

  12. 1-Butyl-3-methylimidazolium Salts as New Catalysts to Produce Epoxy-anhydride Polymers with Improved Properties

    OpenAIRE

    Mikhail S. Fedoseev; Gruzdev, Matvey S.; Lubov F. Derzhavinskaya

    2014-01-01

    We report the curing process of epoxy oligomers by using isomethyltetrahydrophthalic anhydride catalyzed with 1-butyl-3-methylimidazolium salts. Catalytic action has been ascertained to be dependent on the nature of anion. Salts with (Br-) and (PO4-) anions appeared to be most active. Formation of salt adducts with epoxy resin and anhydride is shown. Polymers having higher values of strength and glass transition temperature—as compared with similar epoxy systems cured in the presence of terti...

  13. Biodegradation of methyl tert-butyl ether and other fuel oxygenates by a new strain, Mycobacterium austroafricanum IFP 2012.

    Science.gov (United States)

    François, Alan; Mathis, Hugues; Godefroy, Davy; Piveteau, Pascal; Fayolle, Françoise; Monot, Frédéric

    2002-06-01

    A strain that efficiently degraded methyl tert-butyl ether (MTBE) was obtained by initial selection on the recalcitrant compound tert-butyl alcohol (TBA). This strain, a gram-positive methylotrophic bacterium identified as Mycobacterium austroafricanum IFP 2012, was also able to degrade tert-amyl methyl ether and tert-amyl alcohol. Ethyl tert-butyl ether was weakly degraded. tert-Butyl formate and 2-hydroxy isobutyrate (HIBA), two intermediates in the MTBE catabolism pathway, were detected during growth on MTBE. A positive effect of Co2+ during growth of M. austroafricanum IFP 2012 on HIBA was demonstrated. The specific rate of MTBE degradation was 0.6 mmol/h/g (dry weight) of cells, and the biomass yield on MTBE was 0.44 g (dry weight) per g of MTBE. MTBE, TBA, and HIBA degradation activities were induced by MTBE and TBA, and TBA was a good inducer. Involvement of at least one monooxygenase during degradation of MTBE and TBA was shown by (i) the requirement for oxygen, (ii) the production of propylene epoxide from propylene by MTBE- or TBA- grown cells, and (iii) the inhibition of MTBE or TBA degradation and of propylene epoxide production by acetylene. No cytochrome P-450 was detected in MTBE- or TBA-grown cells. Similar protein profiles were obtained after sodium dodecyl sulfate-polyacrylamide gel electrophoresis of crude extracts from MTBE- and TBA-grown cells. Among the polypeptides induced by these substrates, two polypeptides (66 and 27 kDa) exhibited strong similarities with known oxidoreductases.

  14. Silica-Supported Arsine Palladium(0) Complex: a Highly Active and Stereoselective Catalyst for Arylation of Butyl Acrylate and Acrylamide

    Institute of Scientific and Technical Information of China (English)

    蔡明中; 赵红; 胡文英

    2005-01-01

    A silica-supported arsine palladium(O) complex has been prepared from y-chloropropyltriethoxysilane via immobilization on fumed silica, followed by reaction with potassium diphenylarsenide and palladium chloride, and then reduction with hydrazine hydrate. The complex has been characterized by X-ray photoelectron spectroscopy (XPS) and it is a highly active and stereoselective catalyst for arylation of butyl acrylate and acrylamide with aryl halides, affording a variety of tram-butyl cinnamates and trans-cinnamamides in high yields.

  15. Is the tert-butyl group bulky enough to end-cap a pseudorotaxane with a 24-crown-8-ether wheel?

    Science.gov (United States)

    Tachibana, Yuya; Kihara, Nobuhiro; Furusho, Yoshio; Takata, Toshikazu

    2004-11-25

    Although rotaxane chemists have long believed that the tert-butyl group is bulkier than the cavity of dibenzo-24-crown-8-ether (DB24C8), it is essentially smaller than the cavity of DB24C8. The tert-butyl (or 4-tert-butylphenyl) group can actually function as an end-cap of DB24C8-based rotaxanes when the intercomponent interaction is effectively operative. When such attractive interaction is removed, deslippage occurs. [structure: see text

  16. Molecular structure and spectral investigations of 3,5-Di-tert-butyl-o-benzoquinone

    Science.gov (United States)

    Yilmaz, M.; Aydin, B.; Dogan, O.; Dereli, O.

    2017-01-01

    Conformational analysis of 3,5-Di-tert-butyl-o-benzoquinone molecule was performed and two stable conformers were determined by B3LYP/6-311++G(d,p). Using the most stable one, molecular structural parameters, vibrational frequencies were calculated by B3LYP/6-311++G(d,p), B3LYP/6-31G(d) and BLYP/6-31G(d,p) levels of theory. The FT-IR spectrum of the compound was recorded in the region 4000-550 cm-1. The Raman spectrum was also recorded in the region 3500-100 cm-1. Calculated results were compared with experimental counterparts. The best results were obtained from B3LYP/6-311++G(d,p) calculations. Experimental 13C and 1H NMR data of tittle compound were taken from literature and the calculated results compared with these data. Vibrational and NMR band assignments were performed. HOMO-LUMO energies, molecular electrostatic potentials and thermodynamic properties were also given for further investigations of our structure.

  17. Polymerization rate and mechanism of ultrasonically initiated emulsion polymerization of n-butyl acrylate.

    Science.gov (United States)

    Xia, Hesheng; Wang, Qi; Liao, Yongqin; Xu, Xi; Baxter, Steven M; Slone, Robert V; Wu, Shuguang; Swift, Graham; Westmoreland, David G

    2002-07-01

    The factors affecting the induction period and polymerization rate in ultrasonically initiated emulsion polymerization of n-butyl acrylate (BA) were investigated. The induction period takes only an instant in ultrasonically initiated emulsion polymerization of BA without any added initiator by enhancing the N2 flow rate. Increasing temperature, power output and SDS concentration, decreasing the monomer concentration results in further decreasing induction period and enhanced polymerization rate. Under optimized reaction conditions the conversion of BA reaches 92% in 11 min. The polymerization rate can be controlled by varying reaction parameters. The apparatus of ultrasonically initiated semi-continuous and continuous emulsion polymerization were set up and the feasibility was first studied. Based on the experimental results, a free radical polymerization mechanism for ultrasonically initiated emulsion polymerization was proposed, including the sources of the radicals, the process of radical formation, the locus of polymerization and the polymerization process. Compared with conventional emulsion polymerization, where the radicals come from thermal decomposition of a chemical initiator, ultrasonically initiated emulsion polymerization has attractive features such as no need for a chemical initiator, lower reaction temperature, faster polymerization rate, and higher molecular weight of the polymer prepared.

  18. N-Butyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide-PVdF(HFP) gel electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki-Sub; Park, Seung-Yeob; Yeon, Sun-Hwa; Lee, Huen [Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea)

    2005-09-30

    Ionic liquid-polymer gels were prepared by incorporating N-butyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide (Mor{sub 1,4}TFSI) and poly(vinylidene fluoride)-hexafluoropropylene copolymer (PVdF(HFP)) using three different methods in order to observe the variation of ionic conductivities according to the presence of propylene carbonate (PC) and various weight ratios between Mor{sub 1,4}TFSI and gel polymer electrolyte (GPE). Ionic conductivities for each gel polymer electrolyte were measured with increasing temperature. Ionic conductivities of the GPEs increased with increasing temperature and weight ratio of Mor{sub 1,4}TFSI. In addition, the addition of PC into GPE led to the improvement of ionic conductivities. Thermogravimetric analysis (TGA) showed the suggested gel polymer electrolytes composed of only ionic liquid and polymer were stable up to approximately 400 C. TGA and infrared spectroscopy data indicated that residual PC remains after evaporating PC in a vacuum oven, which did not affect the ionic conductivities. The GPEs containing PC displayed high conductivity (ca. 10{sup -2} S cm{sup -1}) at 60 C. (author)

  19. Transcatheter Arterial Embolization of Nonvariceal Upper Gastrointestinal Bleeding with N-Butyl Cyanoacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Jae, Hwan Jun; Chung, Jin Wook; Jung, Ah Young; Lee, Whal; Park, Jae Hyung [Seoul National University Hospital, Institute of Radiation Medicine, Seoul (Korea, Republic of)

    2007-02-15

    To evaluate the clinical efficacy and safety of transcatheter arterial embolization (TAE) with N-Butyl Cyanoacrylate (NBCA) for nonvariceal upper gastrointestinal bleeding. Between March 1999 and December 2002, TAE for nonvariceal upper gastrointestinal bleeding was performed in 93 patients. The endoscopic approach had failed or was discarded as an approach for control of bleeding in all study patients. Among the 93 patients NBCA was used as the primary embolic material for TAE in 32 patients (28 men, four women; mean age, 59.1 years). The indications for choosing NBCA as the embolic material were: inability to advance the microcatheter to the bleeding site and effective wedging of the microcatheter into the bleeding artery. TAE was performed using 1:1 1:3 mixtures of NBCA and iodized oil. The angiographic and clinical success rate, recurrent bleeding rate, procedure related complications and clinical outcomes were evaluated. The angiographic and clinical success rates were 100% and 91% (29/32), respectively. There were no serious ischemic complications. Recurrent bleeding occurred in three patients (9%) and they were managed with emergency surgery (n = 1) and with a successful second TAE (n = 2). Eighteen patients (56%) had a coagulopathy at the time of TAE and the clinical success rate in this group of patients was 83% (15/18). TAE with NBCA is a highly effective and safe treatment modality for nonvariceal upper gastrointestinal bleeding, especially when it is not possible to advance the microcatheter to the bleeding site and when the patient has a coagulopathy.

  20. Effects of Assistant Solvents and Mixing Intensity on the Bromination Process of Butyl Rubber

    Institute of Scientific and Technical Information of China (English)

    王伟; 邹海魁; 初广文; 向阳; 彭晗; 陈建峰

    2014-01-01

    A slow bromination process of butyl rubber (IIR) suffers from low efficiency and low selectivity (S) of target-product. To obtain suitable approach to intensify the process, effects of assistant solvents and mixing inten-sity on the bromination process were systemically studied in this paper. The reaction process was found constantly accelerated with the increasing dosage and polarity of assistant solvent. Hexane with 30%(by volume) dichloro-methane was found as the suitable solvent component, where the stable conversion of 1,4-isoprene transferring to target product (xA1s) of 80.2%and the corresponding S of 91.2%were obtained in 5 min. The accelerated reaction process was demonstrated being remarkably affected by mixing intensity until the optimal stirring rate of 1100 r·min-1 in a stirred tank reactor. With better mixing condition, a further intensification of the process was achieved in a ro-tating packed bed (RPB) reactor, where xA1s of 82.6% and S of 91.9% were obtained in 2 min. The usage of the suitable solvent component and RPB has potential application in the industrial bromination process intensification.

  1. THERMOPHYSICAL PROPERTIES OF 1-BUTYL-3-METHYLIMIDAZOLIUM BIS(TRIFLUOROMETHYLSULFONYLIMIDE AT HIGH TEMPERATURES AND PRESSURES

    Directory of Open Access Journals (Sweden)

    R. Hamidova

    2015-03-01

    Full Text Available Abstract Pressure-density-temperature (p, ρ ,T data of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonylimide [BMIM][NTF2] at T = (273.15 to 413.15 K and pressures up to p =140 MPa are reported with an estimated experimental relative combined standard uncertainty of Δ ρ / ρ = ±(0.01 to 0.08% in density. The measurements were carried out with a newly constructed Anton-Paar DMA HPM vibration-tube densimeter. The system was calibrated using double-distilled water, aqueous NaCl solution, methanol, toluene and acetone. An empirical equation of state for fitting the (p, ρ ,T data of [BMIM][NTF2] has been developed as a function of pressure and temperature. This equation is used for the calculation of the thermophysical properties of the ionic liquid, such as isothermal compressibility, isobaric thermal expansibility, thermal pressure coefficient, internal pressure, isobaric and isochoric heat capacities, speed of sound and isentropic expansibility.

  2. Effect of nisin and butylated hydroxy anisole on storage stability of buffalo meat sausage.

    Science.gov (United States)

    Sureshkumar, S; Kalaikannan, A; Dushyanthan, K; Venkataramanujam, V

    2010-06-01

    The water activity of buffalo meat sausage was adjusted to 0.88 using humectants and by heat treatment. Nisin and butylated hydroxyanisole (BHA) were added to study the shelf life of sausage. The treatments were nisin 100 ppm + BHA 100 ppm (T3); nisin 100 ppm (T2); BHA 100 ppm (T1) and control (T0) without nisin and BHA. The sausages were vacuum packaged in polyethylene terephthalate (PET-poly) pouch and stored for 7 days at ambient conditions (35 ± 2°C, 70-80% RH). The pH of sausage increased during storage whereas the moisture content was higher in treatment T1. Tyrosine value was lowest (18.1 mg%) in T3. There was no significant difference among T0 and T1. The thiobarbituric acid reactive substances (TBARS) number of T1 and T3 were lower than that of T0 and T2. Nisin and BHA together exhibited a significant inhibitory effect on total viable count, staphylococcal, streptococcal and anaerobic counts. There was no significant difference in the yeast and mould counts among T1-T3. T3 had a better appearance, flavour, texture and overall acceptability scores up to 5 days. The product (T3) was acceptable up to 5(th) day of storage at 35 ± 2°C and 70-80% RH.

  3. Synthesis, characterization and application of 1-butyl-3-methylimidazolium tetrafluoroborate for extractive desulfurization of liquid fuel

    Directory of Open Access Journals (Sweden)

    Swapnil A. Dharaskar

    2016-07-01

    Full Text Available In the present paper the experimental data of extractive desulfurization of liquid fuel using 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM]BF4 have been presented. The data of FTIR, 1H NMR and 13C NMR have been discussed for the molecular confirmation of synthesized [BMIM]BF4. Further, the thermal properties, conductivity, solubility, and viscosity analysis of the [BMIM]BF4 were carried out. The effects of reaction time, reaction temperature, sulfur compounds, and recycling of ionic liquid without regeneration on dibenzothiophene removal of liquid fuel were presented. In extractive desulfurization process, the removal of dibenzothiophene in n-dodecane was 73.02% for mass ratio of 1:1 in 30 min at 30 °C under the mild reaction conditions. The ionic liquids could be reused four times without a significant decrease in activity. Also, the desulfurizations of real fuels, multistage extraction were presented. The data and results provided in the present paper explore the significant insights of imidazoled ILs for extractive desulfurization of liquid fuels.

  4. Synthesis, characterization, and application of 1-butyl-3-methylimidazolium thiocyanate for extractive desulfurization of liquid fuel.

    Science.gov (United States)

    Dharaskar, Swapnil A; Wasewar, Kailas L; Varma, Mahesh N; Shende, Diwakar Z

    2016-05-01

    1-Butyl-3-methylimidazolium thiocyanate [BMIM]SCN has been presented on extractive desulfurization of liquid fuel. The FTIR, (1)H-NMR, and C-NMR have been discussed for the molecular confirmation of synthesized [BMIM]SCN. Further, thermal, conductivity, moisture content, viscosity, and solubility analyses of [BMIM]SCN were carried out. The effects of time, temperature, sulfur compounds, ultrasonication, and recycling of [BMIM]SCN on removal of dibenzothiophene from liquid fuel were also investigated. In extractive desulfurization, removal of dibenzothiophene in n-dodecane was 86.5 % for mass ratio of 1:1 in 30 min at 30 °C under the mild process conditions. [BMIM]SCN could be reused five times without a significant decrease in activity. Also, in the desulfurization of real fuels, multistage extraction was examined. The data and results provided in the present paper explore the significant insights of imidazolium-based ionic liquids as novel extractant for extractive desulfurization of liquid fuels.

  5. Biomarkers of exposure to aromatic hydrocarbons and methyl tert-butyl ether in petrol station workers.

    Science.gov (United States)

    De Palma, Giuseppe; Poli, Diana; Manini, Paola; Andreoli, Roberta; Mozzoni, Paola; Apostoli, Pietro; Mutti, Antonio

    2012-06-01

    This cross-sectional study was aimed at reconstructing the exposure to gasoline in 102 petrol station attendants by environmental and biological monitoring of benzene, toluene, ethylbenzene and xylene (BTEX) and biomonitoring of methyl tert-butyl ether (MTBE). Airborne BTEX were higher for manual refuelers than self-service assistants and were highly correlated with each other. Significant relationships were found between airborne BTX and the corresponding urinary solvents (U-BTX) and beween airborne B and urinary MTBE (U-MTBE). Smokers eliminated higher values of U-B, trans,trans-muconic (t,t-MA) and S-phenylmercapturic (S-PMA) acids but not U-MTBE. All these biomarkers were, however, significantly raised during the shift, independently from smoking. Linear regression confirmed that occupational exposure was a main predictor of U-MTBE, U-B and S-PMA values, both the latter confounded by smoking habits. The study supports the usefulness of biomonitoring even at low exposure levels.

  6. Nonfoaming Bubble Separation for Recovery of Butyl Acetate from Discharged Wastewater During Penicillin Production

    Institute of Scientific and Technical Information of China (English)

    孙兴华; 常志东; 胡欣; 申淑锋; 刘会洲

    2005-01-01

    Two nonfoaming bubble separation techniques, air stripping and solvent sublation, are presented and discussed in order to recover butyl acetate (BA) from discharged wastewater after solvent extraction of penicillin. Results show air stripping is not suitable for the recovery of BA from the wastewater. Axial concentration of BA had a noted maximum point along the column. In contrast, solvent sublation is very effective to recover BA from the wastewater. In solvent sublation experiments, axial concentration of BA along the column first increased and then decreased from the bottom to the top because of two primary mass transport processes. One is the transport by adsorption or attachment to ascending bubbles, and the other is by dispersion at water-solvent interface and by water film in organic solvent layer. In order to elucidate the high removal efficiency in solvent sublation, the microstructure of the wastewater was studied with optic microscope, which was showed to be an emulsion of BA in water at large concentration of BA. Solvent sublation can be successfully used in the removal of BA from its emulsion in the wastewater. The surface tension of simulated solution composed of lysozyme and BA was studied to understand mutual effect of biological materials and BA. Results show that lysozyme affects the adsorption of BA at air-water interface and they may form a complex between BA and lysozyme molecules.

  7. Study of the PVA hydrogel behaviour in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

    Directory of Open Access Journals (Sweden)

    2011-02-01

    Full Text Available The present paper aims at studying the behaviour of the poly(vinyl alcohol [PVA] cryogel in the presence of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]+[BF4]– aqueous solutions with various concentrations. The gravimetric method showed that the swollen PVA cryogels exhibit mechanically active behaviour. PVA cryogels showed shrinking in the presence of ionic liquid, (IL, and re-swelling in the presence of distilled water. The re-swelling is not completely reversible, due to the influence of the IL ions on the gel morphology. The Fourier transform infrared (FTIR spectra have indicated no chemical interaction between the PVA and the studied IL, but highlighted the gel crystallinity change as a function of IL concentration, as well as changes in the bound water amount. Rheological analyses showed dominating plastifying effect of the cation at a lower IL concentration and dominating kosmotropic effect of the anion at a higher IL concentration. A phenomenological kinetic equation that takes into account both fluxes of matters, in and out of the gel, is proposed, explaining the alteration of the gel properties when it comes in contact with BMIMBF4 solutions.

  8. Impetigo herpetiformis occurring during N-butyl-scopolammonium bromide therapy in pregnancy: case report.

    Science.gov (United States)

    Guerriero, C; Lanza Silveri, S; Sisto, T; Rosati, D; De Simone, C; Fossati, B; Pomini, F; Rotoli, M; Amerio, P; Capizzi, R

    2008-01-01

    Impetigo herpetiformis (IH) is a rare dermatosis arising during the third trimester of pregnancy which is generally considered as a form of pustular psoriasis of unknown aetiology. Clinically it is characterized by erythematous plaques surrounded by sterile pustules associated with fever, diarrhea, sweating and increasing risk of stillbirth for placental insufficiency. We describe a case of developed erythematous plaques surrounded by pustules localised initially to the trunk of a 35-year-old woman at the 34th week of gestation after 5 days of treatment with N-Butyl-Scopolammonium, and which later involved the upper and lower limbs. Skin histology confirmed the diagnosis of generalised pregnancy pustular psoriasis (impetigo herpetiformis). IH is reported to be associated with hypocalcemia, hypoparathyroidism, use of oral contraceptives and bacterial infections. This is the first report suggesting the potential role of drugs other than oral contraceptives in the pathogenetic mechanism of this disease. In this case an adverse cutaneous reaction to BB could be the cause of the development of Koebner isomorphism.

  9. Experimental investigation of incremental reactivity of di-tert-butyl peroxide

    Institute of Scientific and Technical Information of China (English)

    DU Lin; XU YongFu; GE MaoFa; JIA Long; YAO Li

    2007-01-01

    Large quantities of di-tert-butyl peroxide(DTBP)have been emitted into the troposphere due to human activities.Its role in the atmospheric photochemical reaction has not been understood.This study presents the results of the photochemical reactions of DTBP and NOx,which have been simulated in a self-made smog chamber under the temperature of(29±1)℃.Both the wall decays of ozone and NO2 could be neglected,compared to the results in simulative experiments.The effective intensity of UV light used in the experiments was 1.28x10-3s-1,which was expressed by the rate constant of NO2 photolysis in purified air.The reaction mechanism was proposed according to our results and reports of other researchers.The maximum values of incremental reactivity(IR)in the three simulative experiments were 9.53x10-2,5.23x10-2 and 3.78x10-2,respectively.The incremental reactivity decreased with the increase of initial concentrations of DTBP.The IR value of DTBP obtained in this study was comparable to that of acetylene reported in our previous research.

  10. The Effect of Tertiary Butyl Hydroquinone on the Biodegradability of Palm Olein

    Directory of Open Access Journals (Sweden)

    Emmanuel ALUYOR

    2009-07-01

    Full Text Available Poor oxidative stability is demonstrated by most vegetable oils especially in industrial situations. Antioxidants are widely used for overcoming poor oxidative stability in vegetable oils. The adverse effect of additives on the overall biodegradability of vegetable oil based industrial fluids could however be a concern. Biodegradability provides an indication of the persistence of any particular substance in the environment. The superior biodegradation of vegetable oils in comparison with mineral based oils has been demonstrated severally, leaving scientists with the lone challenge of finding economic and safe means to improve their working efficiency in terms of their poor oxidative stability. This study investigated the extent to which the use of the antioxidant Tertiary butyl hydroquinone (TBHQ in palm olein impaired biodegradability, and described the relationship between antioxidant loading and biodegradability. Increased antioxidant loading resulted in a matching decrease in biodegradability. Using the total cumulative oxygen depletion value of pure refined palm olein at the end of the 28 day period as a standard of comparison, a 0.02% concentration of TBHQ in palm olein resulted in a 25% loss in biodegradability; a 2% concentration of TBHQ resulted in a 56.5% loss in biodegradability. At 6% TBHQ concentration, no biodegradation was observed in the palm olein sample studied.

  11. Venting Design for Di-tert-butyl Peroxide Runaway Reaction Based on Accelerating Rate Calorimeter Test

    Institute of Scientific and Technical Information of China (English)

    魏彤彤; 蒋慧灵

    2012-01-01

    In order to design the relief system size of di-tert-butyl peroxide(DTBP) storage tanks,the runaway re-action of DTBP was simulated by accelerating rate calorimeter(ARC).The results indicated that under adiabatic conditions the initial exothermic temperature was 102.6 ℃,the maximum self-heating rate was 3.095×107 ℃·min-1,the maximum self-heating temperature was 375.9 ℃,and the pressure produced by unit mass was 4.512 MPa·g-1.Judged by ARC test,the emergency relief system for DTBP was a hybrid system.Based on Design Institute for Emergency Relief System(DIERS) method,the releasing mass flow rate W was determined by Leung methods,and the mass velocity G was calculated by two modified Omega methods.The two relief sizes calculated by monograph Omega method and arithmetic Omega method are close,with only 0.63% relative error.The monograph Omega method is more convenient to apply.

  12. Understanding the chemistry behind the antioxidant activities of butylated hydroxytoluene (BHT): a review.

    Science.gov (United States)

    Yehye, Wageeh A; Rahman, Noorsaadah Abdul; Ariffin, Azhar; Abd Hamid, Sharifah Bee; Alhadi, Abeer A; Kadir, Farkaad A; Yaeghoobi, Marzieh

    2015-08-28

    Hindered phenols find a wide variety of applications across many different industry sectors. Butylated hydroxytoluene (BHT) is a most commonly used antioxidant recognized as safe for use in foods containing fats, pharmaceuticals, petroleum products, rubber and oil industries. In the past two decades, there has been growing interest in finding novel antioxidants to meet the requirements of these industries. To accelerate the antioxidant discovery process, researchers have designed and synthesized a series of BHT derivatives targeting to improve its antioxidant properties to be having a wide range of antioxidant activities markedly enhanced radical scavenging ability and other physical properties. Accordingly, some structure-activity relationships and rational design strategies for antioxidants based on BHT structure have been suggested and applied in practice. We have identified 14 very sensitive parameters, which may play a major role on the antioxidant performance of BHT. In this review, we attempt to summarize the current knowledge on this topic, which is of significance in selecting and designing novel antioxidants using a well-known antioxidant BHT as a building-block molecule. Our strategy involved investigation on understanding the chemistry behind the antioxidant activities of BHT, whether through hydrogen or electron transfer mechanism to enable promising anti-oxidant candidates to be synthesized.

  13. Crystal structure of 5-tert-butyl-10,15,20-triphenylporphyrin

    Directory of Open Access Journals (Sweden)

    Keith J. Flanagan

    2016-02-01

    Full Text Available In the title free base porphyrin, C42H34N4, the neighbouring N...N distances in the center of the ring vary from 2.818 (8 to 2.998 (8 Å and the phenyl rings are tilted from the 24-atom mean plane at angles varying between 62.42 (2–71.63 (2°. The NH groups are involved in intramolecular bifurcated N—H...(N,N hydrogen bonds. The Ca—Cm—Ca angles vary slightly for the phenyl rings, between 124.19 (18–126.17 (18°. The largest deviation from the mean plane of the 24-atom macrocycle is associated with the meso carbon at the substituted tert-butyl position, which is displaced from the mean plane by 0.44 (2 Å. The free base porphyrin is characterized by a significant degree of ruffled (B1u distortion with contributions from domed (A2u and wave [Eg(y and Eg(x] modes. In the crystal, molecules are linked by a number of weak C—H...π interactions, forming a three-dimensional framework. The structure was refined as a two-component inversion twin.

  14. Long-term effects of in utero and lactational exposure to butyl paraben in female rats.

    Science.gov (United States)

    Guerra, Marina Trevizan; Sanabria, Marciana; Cagliarani, Stephannie Vieira; Leite, Gabriel Adan Araújo; Borges, Cibele Dos Santos; De Grava Kempinas, Wilma

    2017-03-01

    Parabens are used as preservatives in cosmetic, pharmaceutical, and food industries, and are frequently detected as contaminants in human fluids and tissues. The endocrine disrupting effects of parabens in female rodents include uterotrophic response, steroidogenesis impairment, and ovarian disturbances. The objective of this study was to determine the effects of maternal butyl paraben (BP) exposure on female sexual development. Pregnant Wistar rats were treated subcutaneously with either corn oil or BP at doses of 10, 100, or 200 mg/kg, from gestational day (GD) 12 until GD 20 for female foetal gonad evaluation, and from GD 12 until the end of lactation to evaluate sexual parameters on the female offspring. Immature female rats were also used in the uterotrophic assay to evaluate the possible estrogenic action of parabens. Our results revealed that, in this experimental protocol, BP did not show estrogenic activity at the doses used and did not impair sexual development and fertility capacity in the female rats, but impaired sexual behavior. We conclude that brain sexual development may be more sensitive to BP effects and we speculate that doses higher than 100 mg/kg (the male lowest observed adverse effect level (LOAEL) for rodent reproductive parameters) would be necessary to promote damages in the female reproduction, regarding the same protocol of exposure. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 776-788, 2017.

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

    Directory of Open Access Journals (Sweden)

    Obie Farobie

    2016-05-01

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

  16. Transcatheter Arterial Embolization of Arterial Esophageal Bleeding with the Use of N-Butyl Cyanoacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Hoon; Kim, Hyo Cheol; Chung, Jin Wook; Jae, Hwan Jun; Park, Jae Hyung [Seoul National University Hospita, Seoul (Korea, Republic of)

    2009-08-15

    To evaluate the clinical efficacy and safety of a transcatheter arterial embolization (TAE) with N-butyl cyanoacrylate (NBCA) for the treatment of arterial esophageal bleeding. Between August 2000 and April 2008, five patients diagnosed with arterial esophageal bleeding by conventional angiography, CT angiography or endoscopy, underwent a TAE with NBCA. We mixed NBCA with iodized oil at ratios of 1:1 to 1:4 to supply radiopacity and achieve a proper polymerization time. After embolization, we evaluated the angiographic and clinical success, recurrent bleeding, and procedure-related complications. The bleeding esophageal artery directly originated from the aorta in four patients and from the left inferior phrenic artery in one patient. Although four patients had an underlying coagulopathy at the time of the TAE, angiographic and clinical success was achieved in all five patients. In addition, no procedurerelated complications such as esophageal infarction were observed during this study. NBCA can be an effective and feasible embolic agent in patients with active arterial esophageal bleeding, even with pre-existing coagulopathy.

  17. Effect of tert-butyl hydroperoxide addition on spontaneous chemiluminescence in brain.

    Science.gov (United States)

    Azorin, I; Bella, M C; Iborra, F J; Fornas, E; Renau-Piqueras, J

    1995-12-01

    It is well known that light emission is related to lipid peroxidation in biological material, and that this process occurs spontaneously in the brain. tert-Butyl hydroperoxide (tBHP) is an organic peroxide widely used as initiator of free radical production in several biological systems. However, the prooxidant capacity of this compound remins unclear. To clarify its role in brain spontaneous autooxidation, rat brain homogenates were incubated with and without tBHP. Light emission and lipid peroxidation were measured by luminometry and the TBARs test, respectively. Several inhibitors of free radical-induced lipid peroxidation were also used. These inhibitors included ascorbate, EDTA, and desferrioxamine. Our results indicate that the pattern of light emission spontaneously produced in brain was different from that observed after the addition of tBHP to the homogenates, and that these differences depended on the tBHP concentration. The main difference was that tBHP caused a rapid light emission that reached its maximum more quickly than in the case of spontaneous emission. Addition of ascorbate resulted in an increase in chemiluminescence in presence of tBHP. In contrast, EDTA and desferrioxamine inhibited light emission in homogenates both with and without tBHP. The results of MDA determination were similar to those described, including the effect of inhibitors. A common feature in MDA and luminometric determinations was the dispersion of data. In conclusion, these results suggest that tBHP, under specific conditions, modify the kinetic pattern of brain spontaneous autooxidation.

  18. Biodegradation Characteristics of Environmental Endocrine Disruptor Di-n-butyl Phthalate

    Institute of Scientific and Technical Information of China (English)

    LIN WANG; QI-FANG LUO

    2005-01-01

    Objective The biodegradation characteristics of di-n-butyl phthalate (DBP), an environmental endocrine disruptor, were studied by the method of dominant bacteria and immobilized microorganisms. Methods Taking DBP as the only carbon source to acclimatize the collected activated sludge, the concentration of DBP increased progressively in the process of acclimatization. Plate streaking was used to separate 1 strain of the degradation dominant bacteria after acclimatization. Better conditions to degrade DBP by the bacterium could be obtained through orthogonal experiments and the bacterium was identified. Then the acclimated activated sludge was made to immobilize the microorganism using polyvinyl alcohol as entrapment agent. The immobilized microorganism degraded DBP at different conditions. Results The appropriate conditions to degrade DBP by the dominant bacteria were: degradation time, 32 h; DBP concentration, 200 mg/L; rate of shaking incubator, 100 r/min; pH, 7 and temperature, 30℃. DBP could be degraded by more than 95% under such conditions. The bacteria were identified as pseudomonas. The proliferated immobilized microorganisms degraded DBP more effectively and more adapted to temperature and pH than the free acclimated activated sludge. Conclusion One strain of DBP degradation dominant bacteria was separated from the acclimatized activated sludge. It could grow with DBP as the only carbon source and energy, and degraded DBP effectively. After having been immobilized and proliferated, the dominant bacteria could keep a higher biological activity and degrade DBP more effectively than activated sludge.

  19. Removal of a type of endocrine disruptors-di-n-butyl phthalate from water by ozonation

    Institute of Scientific and Technical Information of China (English)

    LI Hai-yan; QU Jiu-hui; LIU Hui-juan

    2006-01-01

    Ozonation of synthetic water containing a type of endocrine disruptor-di-n-butyl phthalate (DBP) was examined. Key impact factors such as pH, temperature, ionic strength, ozone dosage and initial DBP concentration were investigated. In addition, the activities of radicals on uncatalysed and catalysed ozonation were studied. The degradation intermediate products were followed and the kinetic of the ozonation were assessed as well. Results revealed that ozonation of DBP followed two mechanisms. Firstly, the reaction rate of direct ozonation was slower at lower pH, temperature, and ionic strength. Secondly, when these factors were increased for indirect radical reaction, higher percentage of DBP was removed with the increase of the initial ozone dosage and the decrease of the initial DBP concentration. In addition, tert-butanol, humic substances and Fe(Ⅱ) affected DBP ozonation through the radical pathway. It was determined that ozonation was restrained by adding tert-butanol for its radical inhibition effect. Furthermore, humic substances enhanced the reaction to some extent, but a slight negative effect would be encountered if the optimum dosage was exceeded. As a matter of fact, Mn(Ⅱ) affected the ozonation by "active sites" mechanism. In the experiment, three different kinds of intermediate products were produced during ozonation, but the amount of products for each one of them decreased as pH, temperature,ionic strength and initial ozone dosage increased. A kinetic equation of the reaction between ozone and DBP was obtained.

  20. Highly ordered cellulose II crystalline regenerated from cellulose hydrolyzed by 1-butyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Ahn, Yongjun; Song, Younghan; Kwak, Seung-Yeop; Kim, Hyungsup

    2016-02-10

    This research focused on the preparation of highly ordered cellulose II crystalline by cellulose hydrolysis in ionic liquid, and the influence of molecular mobility on recrystallization of cellulose. The molar mass of cellulose was controlled by hydrolysis using 1-butyl-3-methylimidazolium chloride (BmimCl). The molecular mobility of cellulose dissolved in BmimCl was characterized by rheological properties. After characterization of cellulose solution and regeneration, change of molar mass and conversion to crystalline were monitored using gel-permeation chromatography and powder X-ray diffraction, respectively. The molar mass of the cellulose in BmimCl was remarkably decreased with an increase in duration time, resulting in better mobility and a lower conformational constraint below critical molar mass. The decrease in molar mass surprisingly increased the crystallinity up to ∼ 85%, suggesting a recrystallization rate dependence of the mobility. The correlation between the mobility and recrystallization rate represented quit different behavior above and below a critical molar mass, which strongly demonstrated to the effect of mobility on the conversion of amorphous state to crystalline structure.

  1. Photosonochemical degradation of butyl-paraben: optimization, toxicity and kinetic studies.

    Science.gov (United States)

    Daghrir, R; Dimboukou-Mpira, A; Seyhi, B; Drogui, P

    2014-08-15

    The objective of the present work is to evaluate the potential of a photosonolysis process for the degradation of butyl-paraben (BPB). After 120 min of treatment time, high removal of BPB was achieved by the photosonolysis (US/UV) process (88.0±0.65%) compared to the photochemical (UV) and the conventional ultrasonication (US) processes. Several factors such as calorimetric power, treatment time, pH and initial concentration of BPB were investigated. Using a 2(4) factorial matrix, the treatment time and the calorimetric power are the main parameters influencing the degradation rate of BPB. Subsequently, a central composite design methodology has been investigated to determine the optimal experimental parameters for BPB degradation. The US/UV process applied under optimal operating conditions (at a calorimetric power of 40 W during 120 min and under pH7) is able to oxidize around 99.2±1.4% of BPB and to record 43.3% of mineralization. During the US/UV process, BPB was mainly transformed into 1 hydroxy BPB, dihydroxy BPB, hydroquinone and 4-hydroxybenzoic acid. Microtox biotests (Vibrio fisheri) showed that the treated effluent was not toxic. The pseudo-first order kinetic model (k=0.0367 min(-1)) described very well the oxidation of BPB.

  2. Studying the Kinetics of n-Butyl-Cyanoacrylate Tissue Adhesive and Its Oily Mixtures

    Science.gov (United States)

    Nedvedova, Marie; Kresalek, Vojtech; Vaskova, Hana; Provaznik, Ivo

    2016-10-01

    This study deals with the measurement of the kinetics of tissue adhesives used for supporting the hemostasis and wound closure during surgical intervention. There are available several types of adhesives of different composition which is closely related with their application. When selecting an appropriate adhesive, the time of curing could play an important role because some applications may require very fast polymerization for prompt vessel or wound closure; conversely, some situations need slower solidification because of longer manipulation with the glue during surgery. The terahertz time-domain spectroscopy is used for studying the kinetics of the n-butyl-cyanoacrylate glue in this study. An oily substance is added to the glue samples to slow the reaction rate. The technique of attenuated total reflection is used in this application; the defined amount of glue sample or its mixture is applied on the silicon crystal and the terahertz response is measured in time. This time dependences are analyzed to find time constants for mathematical description of the glue kinetics. Further, the investigated samples were analyzed using light microscopy and Raman spectroscopy for description of the structures and compositions.

  3. Subchronic, reproductive, and maternal toxicity studies with tertiary butyl acetate (TBAC).

    Science.gov (United States)

    Faber, Willem; Kirkpatrick, Daniel; Coder, Pragati; Li, Abby; Borghoff, Susan; Banton, Marcy

    2014-04-01

    Tertiary-butyl acetate (TBAC) was tested for subchronic toxicity in rats and mice and reproductive toxicity in rats at inhalation concentrations of 0, 100, 400 or 1600ppm. An oral maternal toxicity study was conducted in rats at dose levels of 0, 400, 800, 1000 and 1600mgkg(-1)d(-1). In the inhalation studies, hematology, clinical chemistry, urinalysis, gross pathology and the majority of body weight and feed consumption values were unaffected. Exposure to TBAC at concentrations of 400ppm and higher caused transient hyperactivity in mice and some evidence of increased motor activity counts in male rats at the 1600ppm exposure level. TBAC caused α2u-globulin accumulation in male rat kidneys from all exposure groups and increased liver weights in 1600ppm rats and mice. Levels of thyroxin were decreased in male mice exposed to 1600ppm TBAC for 4weeks but otherwise thyroid endpoints were unaffected in rats and mice at either the 4 or 13weeks time points. There was no evidence or immunotoxicity or reproductive toxicity in rats. Pregnant rats receiving 1000mgkg(-1)d(-1) TBAC exhibited severe signs of acute neurotoxicity and decreased feed consumption and body weight gain. Fetal viability and growth were unaffected.

  4. Coverage dependent isomerisation behaviour of tetra-tert-butyl-imine on Au(111)

    Energy Technology Data Exchange (ETDEWEB)

    Leyssner, Felix; Koch, Matthias; Meyer, Stephan; Tegeder, Petra [Freie Universitaet Berlin, Fachbereich Physik, Arnimallee 14, D-14195 Berlin (Germany)

    2011-07-01

    High resolution electron energy loss spectroscopy (HREELS) is employed to analyze thermally activated changes in the geometrical structure of the photochromic molecular switch 3,3',5,5'-tetra-tert-butyl-imine (TBI) adsorbed on Au(111). Measurements have been performed for two coverage regimes: The monolayer and the bilayer regime. For both coverages all molecules are found in the trans state after deposition at sample temperatures of T=210 K, but conformational changes upon heating are observed, which are assigned to a trans to cis-isomerization. When heating the sample to T=440 K two different conformations are observed depending on the initial coverage. Annealing of a monolayer leads to an increasing number of cis isomers, pointing towards an inverted thermal isomerisation behaviour of TBI, since the trans-isomer is the more stable compound in solution. Whereas for a bilayer the temperature induced isomerization of the TBI can be monitored as well, but desorption of the second layer at T=440 K leads to the formation of a trans-monolayer. The fact that different molecular configurations are found for equal coverages annealed at the same temperature is highly surprising and shows that collective effects may govern the switching properties of molecular switches on surfaces.

  5. Antioxidant effect of mango seed extract and butylated hydroxytoluene in bologna-type mortadella during storage

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Fernandes Pereira

    2011-03-01

    Full Text Available The effects of mango seed extract (MSE and butylated hydroxytoluene (BHT on pH, lipid oxidation, and color of Bologna-type mortadella during refrigerated storage for 21 days were studied. Bologna-type mortadella samples were formulated to contain 0.1% MSE, 0.2% MSE, or 0.01% BHT. After 14 days of storage, the products containing MSE 0.1 or 0.2% had higher pH values than those containing BHT 0.01%. Lipid oxidation values increased with storage time but were not affected by the type of antioxidant. The highest values for color parameter L* were observed for mortadella containing BHT 0.01% after 7, 14, and 21 days of storage. Values for the color parameters a* and b* tended to decrease during mortadella storage. Products containing 0.1 or 0.2% MSE showed higher values for color parameter a* and lower values for color parameter b* compared to those containing 0.01% BHT. It can be concluded that MSE can be used in 0.1 or 0.2% levels in Bologna-type mortadella with similar or better antioxidant effects than those of BHT 0.01%.

  6. Oral subchronic immunotoxicity study of ethyl tertiary butyl ether in the rat.

    Science.gov (United States)

    Banton, Marcy I; Peachee, Vanessa L; White, Kimber L; Padgett, Eric L

    2011-01-01

    The potential for immunotoxicological effects of ethyl tertiary butyl ether (ETBE, CAS RN 637-92-3) was studied in young adult female Crl:CD(SD) rats following subchronic oral exposures. Rats were exposed by gavage once daily for 28 consecutive days to 0, 250, 500, or 1000 mg ETBE/kg body weight (BW)/day; a concurrent positive control group received four intraperitoneal injections of at 50 mg cyclophosphamide monohydrate (CPS)/kg/day on study Days 24-27. Immunotoxicity was evaluated using a splenic antibody-forming cell (AFC) assay to assess T-cell-dependent antibody responses in rats sensitized with sheep red blood cells (SRBC). All rats survived to the scheduled necropsy. There were no effects on clinical observations, body weights, feed or water consumption, or macroscopic pathology findings in the ETBE-treated rats. No ETBE-related effects were observed on absolute or relative (to final body weight) spleen or thymus weights, spleen cellularity, or on the specific (AFC/10(6) spleen cells) or total activity (AFC/spleen) of splenic IgM AFC to the T-cell-dependent antigen SRBC. CPS produced expected effects consistent with its known immunosuppressive properties and validated the appropriateness of the AFC assay. Based on the results of this study, ETBE did not suppress the humoral component of the immune system in female rats. The no-observed-effect level for immunotoxicity was the highest dosage tested at 1000 mg/kg/day.

  7. Hepatotumorigenicity of ethyl tertiary-butyl ether with 2-year inhalation exposure in F344 rats.

    Science.gov (United States)

    Saito, Arata; Sasaki, Toshiaki; Kasai, Tatuya; Katagiri, Taku; Nishizawa, Tomoshi; Noguchi, Tadashi; Aiso, Shigetoshi; Nagano, Kasuke; Fukushima, Shoji

    2013-05-01

    Carcinogenicity of ethyl tertiary-butyl ether (ETBE) was examined with inhalation exposure using F344/DuCrlCrlj rats. Groups of 50 male and 50 female rats, 6 week old at commencement, were exposed to ETBE at 0, 500, 1,500 or 5,000 ppm (v/v) in whole-body inhalation chambers for 6 h/day, 5 days/week for 104 weeks. A significant increase in the incidence of hepatocellular adenomas was indicated in males exposed at 5,000 ppm, but not in females at any concentration. In addition, significantly increased incidences of eosinophilic and basophilic cell foci were observed in male rats at 5,000 ppm. Regarding non-neoplastic lesions, rat-specific changes were observed in kidney, with an increase in the severity of chronic progressive nephropathy in both sexes at 5,000 ppm. Increased incidences of urothelial hyperplasia of the pelvis were observed at 1,500 ppm and above, and mineral deposition was apparent in the renal papilla at 5,000 ppm in males. There were no treatment-related histopathological changes observed in any other organs or tissues in either sex. The present 2-year inhalation study demonstrated hepatotumorigenicity of ETBE in male, but not in female rats.

  8. Prenatal developmental toxicity study of ethyl tertiary-butyl ether in rabbits.

    Science.gov (United States)

    Asano, Yuzo; Ishikura, Toshikazu; Kudoh, Kayoko; Haneda, Ryo; Endoh, Takako

    2011-07-01

    Ethyl tertiary-butyl ether (ETBE) is commonly used as an oxygenated gasoline additive. In this study, the prenatal developmental toxicity of ETBE was determined in rabbits. New Zealand white rabbits were given ETBE by gavage at 100, 300, or 1,000 mg/kg/day on gestational days (GDs) 6-27, and the pregnancy outcome was determined on GD 28. Neither death nor abortion occurred in the pregnant rabbits at any dose. Slightly and significantly suppressed maternal body-weight gain and transiently decreased maternal food consumption were found at 1,000 mg/kg/day during the administration period. At this dose, no changes in clinical or macroscopic finding were noted in dams. No treatment-related changes were observed in any dam treated at 300 mg/kg/day or less. There was no significant effect of ETBE on the numbers of corpora lutea, implantations, live fetuses, resorptions and dead fetuses, incidences of pre- and postimplantation loss, viability of fetuses, fetal body weight, sex ratio of fetuses, or weights of gravid uteri. No significant difference was detected in the incidences of fetuses with malformations or variations between the ETBE-treated and control groups. Also, no adverse effects on the progress of ossification were noted in fetuses of dams given ETBE. Based on these findings, it is concluded that the no observed adverse effect levels of ETBE were 300 mg/kg/day for dams and 1,000 mg/kg/day for fetuses in rabbits.

  9. Predicted and experimental crystal structures of ethyl-tert-butyl ether.

    Science.gov (United States)

    Hammer, Sonja M; Alig, Edith; Fink, Lothar; Schmidt, Martin U

    2011-04-01

    Possible crystal structures of ethyl-tert-butyl ether (ETBE) were predicted by global lattice-energy minimizations using the force-field approach. 33 structures were found within an energy range of 2 kJmol(-1) above the global minimum. Low-temperature crystallization experiments were carried out at 80-160 K. The crystal structure was determined from X-ray powder data. ETBE crystallizes in C2/m, Z = 4, with molecules on mirror planes. The ETBE molecule adopts a trans conformation with a (CH(3))(3)C-O-C-C torsion angle of 180°. The experimental structure corresponds with high accuracy to the predicted structure with energy rank 2, which has an energy of 0.54 kJmol(-1) above the global minimum and is the most dense low-energy structure. In some crystallization experiments a second polymorph was observed, but the quality of the powder data did not allow the determination of the crystal structure. Possibilities and limitations are discussed for solving crystal structures from powder diffraction data by real-space methods and lattice-energy minimizations.

  10. A one-generation reproductive toxicity study of ethyl tertiary butyl ether in rats.

    Science.gov (United States)

    Fujii, Sakiko; Yabe, Kaoru; Furukawa, Masatoshi; Matsuura, Masao; Aoyama, Hiroaki

    2010-11-01

    A one-generation reproductive toxicity study was conducted to evaluate the effects of ethyl tertiary butyl ether (ETBE), a bio-fuel, on reproduction of parental rats, as well as development and growth of their offspring at dose levels of 0, 100, 300 and 1000 mg/kg-d by gavage. No treatment-related changes were observed in either F0 parents or their F1 offspring in the 100 and 300 mg/kg groups in any parameters examined. Some parental animals in the 1000 mg/kg group exhibited transient salivation, possibly a reflex to a bitter taste of ETBE, immediately after dosing, although their body weights, food consumption, reproductive parameters, and gross pathological findings were not affected. Their absolute and relative liver weights increased significantly in the 1000 mg/kg group, suggesting enhanced activities of metabolic enzymes. Pup viability was slightly reduced during the early lactation period in the 1000 mg/kg group. These results lead to the conclusion that the no-observed-adverse-effect-level (NOAEL) of ETBE on both parental rats and their offspring is 300 mg/kg-d under the current study condition.

  11. Prenatal developmental toxicity study of ethyl tertiary-butyl ether in rats.

    Science.gov (United States)

    Aso, Sunao; Miyata, Katsumi; Takakura, Saori; Hoshuyama, Satsuki; Muroi, Takako; Kusune, Yuji; Ajimi, Shozo; Furukawa, Kotaro

    2014-01-01

    Ethyl tertiary-butyl ether (ETBE) is commonly used as an oxygenated gasoline additive. In this study, we evaluated its developmental toxicity in rats. ETBE was administered by gavage to 21 or 22 pregnant female Sprague-Dawley rats per group at dose levels of 0, 100, 300 and 1000 mg/kg/day from days 5 through 19 postcoitum to assess its effects on pregnant animals and their embryos and fetuses applied to the OECD testing guideline (no. 414) correspondingly. There were no toxicological effects attributable to ETBE regarding clinical signs, body weight, food intake, necropsy or examination at caesarean section in pregnant animals. There were also no toxicological effects on external, visceral and skeletal examinations of embryos and fetuses. These results indicate that, under the conditions of this study, ETBE had no toxicological effects on pregnant rats or their embryos and fetuses and that the no observed adverse effect level was 1000 mg/kg/day both for pregnant rats and their embryos and fetuses.

  12. No carcinogenicity of ethyl tertiary-butyl ether by 2-year oral administration in rats.

    Science.gov (United States)

    Suzuki, Masaaki; Yamazaki, Kazunori; Kano, Hirokazu; Aiso, Shigetoshi; Nagano, Kasuke; Fukushima, Shoji

    2012-01-01

    The carcinogenicity of ethyl tertiary-butyl ether (ETBE) was examined by oral administration using F344/DuCrlCrlj rats. Groups of 50 male and 50 female rats were given drinking water containing ETBE at doses of 0, 625, 2,500 or 10,000 ppm (w/w) for 104 weeks. No significant increase in the incidence of tumors was detected in any organ of either sex. Rat-specific non-neoplastic lesions were observed in the kidney: An increase in the severity of chronic progressive nephropathy was observed in the male and female 10,000 ppm groups, and increased incidences of urothelial hyperplasia of the pelvis and mineral deposition in the renal papilla were observed in the male 2,500 and 10,000 ppm groups. Besides these lesions, no treatment-related histopathological changes were observed in any organ or tissue in either sex. Thus, the present study demonstrated that a two year administration ETBE in the drinking water did not exert any carcinogenic effects in either male or female rats.

  13. Preparation and characterization of lignin based macromonomer and its copolymers with butyl methacrylate.

    Science.gov (United States)

    Liu, Xiaohuan; Wang, Jifu; Yu, Juan; Zhang, Mingming; Wang, Chunpeng; Xu, Yuzhi; Chu, Fuxiang

    2013-09-01

    Copolymerization of butyl methacrylate (BMA) with biobutanol lignin (BBL) was achieved by free-radical polymerization (FRP) using a lignin-based macromonomer. The lignin-based macromonomer containing acrylic groups was prepared by reacting acryloyl chloride with biobutanol lignin using triethylamine (TEA) as absorb acid agentin. From the results of elemental analysis and GPC, the average degree of polymerization (DP) of BBL was estimated to be five. A detailed molecular characterization has been performed, including techniques such as (1)H NMR, (13)C NMR and UV-vis spectroscopies, which provided quantitative information about the composition of the copolymers. The changes in the solubility of lignin-g-poly(BMA) copolymers in ethyl ether were dependent on the length of poly(BMA) side chain. TGA analysis indicated that the lignin-containing poly(BMA) graft copolymers exhibited high thermal stability. The bulky aromatic group of lignin increased the glass-transition temperature of poly(BMA). In order to confirm the main structure of copolymer, (AC-g-BBL)-co-BMA copolymer was also synthesized by atom transfer radical polymerization (ATRP), and the results revealed that the copolymer prepared by ATRP had the same solution behavior as that prepared by FRP, and the lignin-based macromonomer showed no homopolymerizability due to the steric hindrance. In addition, the lignin-co-BMA copolymer had a surprisingly higher molecular weight than poly(BMA) under the same reaction condition, suggesting that a branched lignin based polymer could be formed.

  14. Post-discharge treatment of air effluents polluted by butyl-mercaptan: the role of nitrate radical

    Science.gov (United States)

    Liu, Y. N.; Braci, L.; Cavadias, S.; Ognier, S.

    2011-03-01

    Dry air polluted by butyl-mercaptan was treated in a dielectric barrier discharge reactor at atmospheric pressure using air as plasmagene gas in discharge and post-discharge modes. The energy density was varied between 200 and 1300 J l-1. To assess the treatment efficiency, the concentrations of butyl-mercaptan, total volatile organic compounds (VOCs) and SO2 were determined in the exhaust gas. Whatever the energy density was, the treatment efficiency was better in the post-discharge mode. Butyl-mercaptan could be completely eliminated from 400 J l-1 and SO2 selectivity was always low, below 10%. Measurements of CO, CO2 and total VOCs indicated that 50-70% of the reaction products were condensed on the reactor wall in the form of micro-droplets, depending on the energy density. FTIR and XPS techniques were used to characterize the reaction products which were soluble in water. These analyses indicated that the reaction products contained oxygen, nitrogen and sulfur in an oxidized form. A reaction mechanism involving hydrogen abstraction from the -SH bond by the nitrate radical was proposed, pointing out the important role of nitrate radicals NO3 in the reactivity of air flowing post-discharge.

  15. Distribution Equilibrium of o-Phthalic Acid and trans-Butenedioic in Water and Di-n-butyl Phthalate

    Institute of Scientific and Technical Information of China (English)

    GAO Zhenghong; YANG Xiaorui; HU Chaoquan; LI Jiang

    2006-01-01

    The organic dissolvent(di-n-butyl phthalate)needs to be washed by water to recycle itself in the process of recovering maleic anhydride by organic dissolvent. The design and optimization of the extraction process require the distribution coefficients of the organic solutes, o-phthalic acid and trans-butenedioic in water and di-n-butyl phthalate, on which the extraction efficiency depends. In this study, the distribution coefficients of o-phthalic acid and trans-butenedioic in water and di-n-bu-tyl phthalate(DBP)at 298.15 K, 318.15 K and 333.15 K were determined respectively by acid-alkali titration. The dissociation constants of o-phthalic acid and trans-butenedioic at those temperatures were obtained by fitting the measured hydrogen-ion concentrations and the known solute concentrations in the aqueous solution containing the two organic solutes. Then the distribution constants were calculated. Both the distribution coefficients and the distribution constants increase along with the temperature increasing. And the distribution coefficients at 333.15 K are large enough to ensure the efficiency of extraction process. In addition, the mutual solubility of water and di-n-butyl phthalate at 298.15 K, 318.15 K and 333.15 K was also measured respectively by High Performance Liquid Chromatography and Karl Fischer Watertitration, which was not more than 0.5%(mass fraction).

  16. Aerobic degradation of methyl tert-butyl ether by a Proteobacteria strain in a closed culture system

    Institute of Scientific and Technical Information of China (English)

    ZHONG Wei-hong; CHEN Jian-meng; LU Zheng; CHEN Dong-zhi; CHEN Xiao

    2007-01-01

    The contamination of methyl tert-butyl ether (MTBE) in underground waters has become a widely concerned problem all over the world. In this study, a novel closed culture system with oxygen supplied by H2O2 was introduced for MTBE aerobic biodegradation. After 7 d, almost all MTBE was degraded by a pure culture, a member of β-Proteobacteria named as PM1, in a closed system with oxygen supply, while only 40% MTBE was degraded in one without oxygen supply. Dissolved oxygen (DO) levels of the broth in closed systems respectively with and without H2O2 were about 5-6 and 4 mg/L. Higher DO may improve the activity of monooxygemase, which is the key enzyme of metabolic pathway from MTBE to tert-butyl alcohol and finally to CO2, and may result in the increase of the degrading activity of PM1 cell. The purge and trap GC-MS result of the broth in closed systems showed that tert-butyl alcohol,isopronol and acetone were the main intermediate products.

  17. Urinary methyl tert-butyl ether and benzene as biomarkers of exposure to urban traffic.

    Science.gov (United States)

    Campo, Laura; Cattaneo, Andrea; Consonni, Dario; Scibetta, Licia; Costamagna, Paolo; Cavallo, Domenico M; Bertazzi, Pier Alberto; Fustinoni, Silvia

    2011-02-01

    Methyl tert-butyl ether (MTBE) and benzene are added to gasoline to improve the combustion process and are found in the urban environment as a consequence of vehicular traffic. Herein we evaluate urinary MTBE (MTBE-U) and benzene (BEN-U) as biomarkers of exposure to urban traffic. Milan urban policemen (130 total) were investigated in May, July, October, and December for a total of 171 work shifts. Personal exposure to airborne benzene and carbon monoxide (CO), and atmospheric data, were measured during the work shift, while personal characteristics were collected by a questionnaire. A time/activity diary was completed by each subject during the work shift. Spot urine samples were obtained for the determination of MTBE-U and BEN-U. Median personal exposure to CO and airborne benzene were 3.3 mg/m(3) and 9.6 μg/m(3), respectively; median urinary levels in end-of-shift (ES) samples were 147 ng/L (MTBE-U) and 207 ng/L (BEN-U). The time spent on traffic duty at crossing was about 40% of work time. Multiple linear regression models, taking into account within-subject correlations, were applied to investigate the role of urban pollution, atmospheric conditions, job variables and personal characteristics on the level of biomarkers. MTBE-U was influenced by the month of sampling and positively correlated to the time spent in traffic guarding, CO exposure and atmospheric pressure, while negatively correlated to wind speed (R(2) for total model 0.63, P<0.001). BEN-U was influenced by the month and smoking habit, and positively correlated to urinary creatinine; moreover, an interaction between CO and smoking was found (R(2)=0.62, P<0.001). These results suggest that MTBE-U is a reliable marker for assessing urban traffic exposure, while BEN-U is determined mainly by personal characteristics.

  18. Ameliorative effect of butylated hydroxyanisole against ferric nitrilotriacetate-induced hepatotoxicity and oxidative stress in rats.

    Science.gov (United States)

    Ansar, S; Iqbal, M

    2015-11-01

    Ferric nitrilotriacetate (Fe-NTA) is a known renal carcinogen and has been shown to adversely induce oxidative stress and tissue toxicity after both acute and chronic exposure. Present studies were designed to study the hepatoprotective and antioxidant potential of butylated hydroxyanisole (BHA), a phenolic antioxidant used in foods on ferric nitrilotriacetate (Fe-NTA) induced hepatotoxicity in rats. Male albino rats of Wistar strain (4-6 weeks old) weighing 125-150 g were used in this study. Animals were given a single dose of Fe-NTA (9 mg/kg body weight, intraperitoneal) after a week's treatment with BHA. BHA was administered orally once daily for 7 days at doses of 1 and 2 mg/animal/day. The hepatoprotective activity was assessed using various biochemical parameters as serum transaminases (alanine transaminase (ALT), aspartate transaminase (AST)) and lactate dehydrogenase (LDH). Fe-NTA treatment increased ALT, AST, and LDH levels significantly when compared to the corresponding saline-treated group (p < 0.001). Fe-NTA also depleted the levels of glutathione and the activities of antioxidant enzymes namely glutathione reductase and glutathione-S-tranferase (p < 0.05). Pretreatment with BHA significantly decreased ALT, AST and LDH levels in a dose-dependent manner (p < 0.05). BHA also increased antioxidant enzymes level and decreased lipid peroxidation and hydrogen peroxide generation to 1.3-1.5-fold as compared to Fe-NTA-treated group. The results show the strong hepatoprotective activity of BHA which could be due to its potent antioxidant effects.

  19. Spin probing of supramolecular structures in 1-butyl-3-methyl-imidazolium tetrafluoroborate/water mixtures

    Science.gov (United States)

    Kattnig, Daniel R.; Akdogan, Yasar; Lieberwirth, Ingo; Hinderberger, Dariush

    2013-10-01

    We have systematically studied micro-heterogeneous mixtures of the room temperature ionic liquid 1-butyl-3-methyl-imidazolium tetrafluoroborate ([bmim+][BF4-]) and water using continuous wave electron paramagnetic resonance (CW EPR) and the spin-probing methodology. Using cryo TEM, a mesoscopic picture of the micro-heterogeneous mixtures could be revealed. Six spin-probes differing in polarity, charge and Lewis basicity have been used to map the dependence of the micro-polarity and rotation motion of the probe on the ionic liquid (IL) concentration. The electron paramagnetic resonance (EPR) spectra of all probe molecules have been found to be unimodal. The critical aggregation concentration has been determined and the local water concentration sensed by the probes extracted from the Mukerjee hydrophilicity index. Surprisingly, four probes of the piperidinoxyl type were found to sense very similar local water concentrations irrespective of the substituent, monovalent ionic or H-bonding, at the 4-position. Using a simple geometrical model of the primary IL aggregates observed in the micro-heterogeneous concentration range, we show that these probes cannot be statically located within the aggregates on the EPR timescale. Instead, diffusive trajectories of the probe molecules extend into the aqueous phase, i.e. aqueous and [bmim+][BF4-]-rich phases are sampled by the probes in swift succession. No details of the internal structure of the [bmim+][BF4-] aggregates can in general be elucidated by the spin-probing methodology under these conditions. On the other hand, the dianionic Fremy's salt binds to the surface of the IL aggregates thereby sampling predominantly the aqueous phase. At large IL concentrations, a micro-viscosity drastically smaller than the macroscopic viscosity is typically observed. Supplementary Materials (Figures S1-S5) for this paper are available online on the journal website.

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

    Science.gov (United States)

    Stern, B R; Tardiff, R G

    1997-12-01

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

  1. Gene expression profiling of di-n-butyl phthalate in normal human mammary epithelial cells.

    Science.gov (United States)

    Gwinn, Maureen R; Whipkey, Diana L; Tennant, Lora B; Weston, Ainsley

    2007-01-01

    Studies show that female workers in the personal-care industry have an increased risk of developing cancer believed to be the result of increased exposure to toxic and/or carcinogenic chemicals found in cosmetics, hair dyes, and nail polish. One chemical found in multiple personal-care products, di-n-butyl phthalate (DBP), is a known endocrine disruptor and has been found in increased levels in women of childbearing age. The goal of this study was to elucidate mechanisms of phthalate toxicity in normal human cells to provide information concerning interindividual variation and gene-environment interactions. Normal human mammary epithelial cell strains were obtained from discarded tissues following reduction mammoplasty [Cooperative Human Tissue Network (sponsors: NCI/NDRI)]. Gene transcription in each cell strain was analyzed using high-density oligonucleotide DNA microarrays (U133A, Affymetrix) and changes in the expression of selected genes were verified by real-time polymerase chain reaction (PCR) (ABI). DNA microarrays were hybridized with total RNA that was collected after DBP treatment for 5 hr and 10 hr. RNA was harvested from the vehicle control (acetone) at 10 hr. Data Mining Tool software (Affymetrix) was used to separate genes in clusters based on their expression patterns over time. Only 57 genes were found to be altered in all four cell strains following exposure to DBP. These included genes involved in fertility (inhibin, placental growth factor), immune response (tumor necrosis factor induced protein), and antioxidant status (glutathione peroxidase). Data from this study will help clarify the role of DBP in reproductive toxicity, and yield biomarkers of exposure for future epidemiology studies.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-09-01

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

  3. Percutaneous Transportal Sclerotherapy with N-Butyl-2-Cyanoacrylate for Gastric Varices: Technique and Clinical Efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Hyo Sung; Han, Young Min [Chonbuk National University Medical School and Hospital, Jeonju (Korea, Republic of)

    2008-12-15

    This study was deigned to evaluate the technique and clinical efficacy of the use of percutaneous transportal sclerotherapy with N-butyl-2-cyanoacrylate (NBCA) for patients with gastric varices. Seven patients were treated by transportal sclerotherapy with the use of NBCA. For transportal sclerotherapy, portal vein catheterization was performed with a 6-Fr sheath by the transhepatic approach. A 5-Fr catheter was introduced into the afferent gastric vein and a microcatheter was advanced through the 5-Fr catheter into the varices. NBCA was injected through the microcatheter in the varices by use of the continuous single-column injection technique. After the procedure, postcontrast computed tomography (CT) was performed on the next day and then every six months. Gastroendoscopy was performed at one week, three months, and then every six months after the procedure. The technical success rate of the procedure was 88%. In six patients, gastric varices were successfully obliterated with 1-8 mL (mean, 5.4 mL) of a NBCA-Lipiodol mixture injected via a microcatheter. No complications related to the procedure were encountered. As seen on the follow-up endoscopy and CT imaging performed after six months, the presence of gastric varcies was not seen in any of the patients after treatment with the NBCA-Lipiodol mixture and the use of microcoils. Recurrence of gastric varices was not observed during the followup period. Worsening of esophageal varices occurred in four patients after transportal sclerotherapy. The serum albumin level increased, the ammonia level decreased and the prothrombin time increased at six months after the procedure (p < 0.05). Percutaneous transportal sclerotherapy with NBCA is useful to obliterate gastric varices if it is not possible to perform balloon-occluded retrograde transvenous obliteration.

  4. Effects of subchronic inhalation exposure to ethyl tertiary butyl ether on splenocytes in mice.

    Science.gov (United States)

    Li, Q; Kobayashi, M; Inagaki, H; Hirata, Y; Hirata, K; Shimizu, T; Wang, R-S; Suda, M; Kawamoto, T; Nakajima, T; Kawada, T

    2011-01-01

    Ethyl tertiary-butyl ether (ETBE) is a motor fuel oxygenate used in reformulated gasoline. The current use of ETBE in gasoline or petrol is modest but increasing. To investigate the effects of ETBE on splenocytes, mice were exposed to 0 (control), 500 ppm, 1750 ppm, or 5000 ppm of ETBE by inhalation for 6 h/day for 5 days/wk over a 6- or 13-week period. Splenocytes were harvested from the control and exposed mice, and the following cell phenotypes were quantified by flow cytometry: (1) B cells (PerCP-Cy5.5-CD45R/B220), (2) T cells (PerCP-Cy5-CD3e), (3) T cell subsets (FITC-CD4 and PE-CD8a), (4) natural killer (NK) cells (PE-NK1.1), and (5) macrophages (FITC-CD11b). Body weight and the weight of the spleen were also examined. ETBE-exposure did not affect the weight of the spleen or body weight, while it transiently increased the number of RBC and the Hb concentration. The numbers of splenic CD3+, CD4+, and CD8+ T cells, the percentage of CD4+ T cells and the CD4+/CD8+ T cell ratio in the ETBE-exposed groups were significantly decreased in a dose-dependent manner. However, ETBE exposure did not affect the numbers of splenic NK cells, B cells, or macrophages or the total number of splenocytes. The above findings indicate that ETBE selectively affects the number of splenic T cells in mice.

  5. Medium-term multi-organ carcinogenesis bioassay of ethyl tertiary-butyl ether in rats.

    Science.gov (United States)

    Hagiwara, Akihiro; Doi, Yuko; Imai, Norio; Nakashima, Hironao; Ono, Takahiro; Kawabe, Mayumi; Furukawa, Fumio; Tamano, Seiko; Nagano, Kasuke; Fukushima, Shoji

    2011-11-18

    The modifying potential of ethyl tertiary-butyl ether (ETBE) on tumor development was investigated in a medium-term multi-organ carcinogenesis bioassay using male F344 rats. Animals were sequentially given 5 carcinogens with different target sites in the first 4 weeks for multi-organ initiation. After one week they received ETBE by gavage at dose levels of 0 (control), 300 or 1000mg/kg/day until experimental week 28. Further groups were also given ETBE at doses of 0 or 1000mg/kg/day without prior carcinogen application. Incidences and multiplicities of follicular cell hyperplasias and neoplasms in the thyroid were significantly increased at dose levels of more than 300mg/kg/day. Combined incidences of squamous cell hyperplasias and papillomas of the forestomach were also significantly increased at 300 and 1000mg/kg/day. Incidences and multiplicities of adenocarcinomas in the colon were increased at 1000mg/kg/day. The numbers and areas of glutathione S-transferase placental form (GST-P) positive foci per unit area of the liver sections, and the incidence of hepatocellular adenomas were also significantly increased at 1000mg/kg/day, along with multiplicities of atypical hyperplasias of renal tubules of the kidney and the incidence of papillomatosis of the urinary bladder. This latter lesion was also seen at low incidence at 1000mg/kg/day without initiation. Thus, the current results indicate that ETBE has tumor promoting potential for the thyroid and forestomach at dose levels of 300mg/kg/day and more, and for the colon, liver, kidney and urinary bladder at 1000mg/kg/day, under the present experimental conditions.

  6. Free radical-derived quinone methide mediates skin tumor promotion by butylated hydroxytoluene hydroperoxide: expanded role for electrophiles in multistage carcinogenesis.

    Science.gov (United States)

    Guyton, K Z; Bhan, P; Kuppusamy, P; Zweier, J L; Trush, M A; Kensler, T W

    1991-01-01

    Free radical derivatives of peroxides, hydroperoxides, and anthrones are thought to mediate tumor promotion by these compounds. Further, the promoting activity of phorbol esters is attributed, in part, to their ability to stimulate the cellular generation of oxygen radicals. A hydroperoxide metabolite of butylated hydroxytoluene, 2,6-di-tert-butyl-4-hydroperoxyl-4-methyl-2,5-cyclohexadienone (BHTOOH), has previously been shown to be a tumor promoter in mouse skin. BHTOOH is extensively metabolized by murine keratinocytes to several radical species. The primary radical generated from BHTOOH is a phenoxyl radical that can disproportionate to form butylated hydroxytoluene quinone methide, a reactive electrophile. Since electrophilic species have not been previously postulated to mediate tumor promotion, the present study was undertaken to examine the role of this electrophile in the promoting activity of BHTOOH. The biological activities of two chemical analogs of BHTOOH, 4-trideuteromethyl-BHTOOH and 4-tert-butyl-BHTOOH, were compared with that of the parent compound. 4-Trideuteromethyl-BHTOOH and 4-tert-butyl-BHTOOH have a reduced ability or inability, respectively, to form a quinone methide; however, like the parent compound, they both generate a phenoxyl radical when incubated with keratinocyte cytosol. The potency of BHTOOH, 4-trideuteromethyl-BHTOOH, and 4-tert-butyl-BHTOOH as inducers of ornithine decarboxylase, a marker of tumor promotion, was commensurate with their capacity for generating butylated hydroxytoluene quinone methide. These initial results were confirmed in a two-stage tumor promotion protocol in female SENCAR mice. Together, these data indicate that a quinone methide is mediating tumor promotion by BHTOOH, providing direct evidence that an electrophilic intermediate can elicit this stage of carcinogenesis. PMID:1846971

  7. Physiologically based pharmacokinetic model for ethyl tertiary-butyl ether and tertiary-butyl alcohol in rats: Contribution of binding to α2u-globulin in male rats and high-exposure nonlinear kinetics to toxicity and cancer outcomes.

    Science.gov (United States)

    Borghoff, Susan J; Ring, Caroline; Banton, Marcy I; Leavens, Teresa L

    2017-05-01

    In cancer bioassays, inhalation, but not drinking water exposure to ethyl tertiary-butyl ether (ETBE), caused liver tumors in male rats, while tertiary-butyl alcohol (TBA), an ETBE metabolite, caused kidney tumors in male rats following exposure via drinking water. To understand the contribution of ETBE and TBA kinetics under varying exposure scenarios to these tumor responses, a physiologically based pharmacokinetic model was developed based on a previously published model for methyl tertiary-butyl ether, a structurally similar chemical, and verified against the literature and study report data. The model included ETBE and TBA binding to the male rat-specific protein α2u-globulin, which plays a role in the ETBE and TBA kidney response observed in male rats. Metabolism of ETBE and TBA was described as a single, saturable pathway in the liver. The model predicted similar kidney AUC0-∞ for TBA for various exposure scenarios from ETBE and TBA cancer bioassays, supporting a male-rat-specific mode of action for TBA-induced kidney tumors. The model also predicted nonlinear kinetics at ETBE inhalation exposure concentrations above ~2000 ppm, based on blood AUC0-∞ for ETBE and TBA. The shift from linear to nonlinear kinetics at exposure concentrations below the concentration associated with liver tumors in rats (5000 ppm) suggests the mode of action for liver tumors operates under nonlinear kinetics following chronic exposure and is not relevant for assessing human risk. Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd.

  8. Preparation and Catalytic Activity of SO42-/TiO-La2O3 in Synthesis of Butyl Butyrate

    Institute of Scientific and Technical Information of China (English)

    YANG Shui-jin; LUO Yi; BAI Ai-min; HU Zhen-zhu; CHEN Fang

    2004-01-01

    Butyl butyrate is a very important compound, which is transparent liquid and has the pear,apple flavor. Natural exist is in the fruit, such as apple, pear, banana, grape and strawberry, etc.Primarily used for to prepare the edible spice and is also widely used in industrial intermediate product, solvent and synthetic perfumery. Until now, there are many methods to synthesize it.Conventionally H2SO4 was reported, but it causes many problems, such as the erosion of equipment,easily causes the vice-reaction, difficulty for after-treatment, environment pollution etc. A new environmentally friendly catalyst, SO42-/TiO2-La2O3 was prepared. And catalytic activity of catalyst in esterification of n-butanoic acid and n-butyl alcohol with SO42-/TiO2-La2O3 as catalyst has been no report up to now. Therefore, studying on the synthetic catalyst has theoretical and practical significances. The catalytic activity of catalyst in esterification of n-butanoic acid and n-butyl alcohol was measured.In this paper, we fast reported the preparation of SO42-/riO2-La2O3 and discussed the factors influencing the synthesis catalyst. The catalyst rare earth solid superacid SO42-/TiO2-La2O3 was The precipitate was filtered and washed thoroughly with distilled water until chloride ions were free.furnace at 480 ℃ for 3 h, and finally stored in a desiccator until use.The factors influencing the synthesis were discussed and the best conditions were found out. The experiment indicated that this catalyst has the following advantage. The amount of catalyst was little and getting high yield, its product has a good quanlity and is favour of reducing erosion of equipment, avoiding environment pollution. The optimum conditions are: molar ratio of n-butanoic acid to n-butyl alcohol was 1:1.5, the quantity of catalyst was equal to 1.5% of feed stocks, the reaction temperature was 93-114 ℃, and the reaction time was 1.0 h. Rare earth solid superacid SO42-/TiO2-La2O3 is an excellent catalyst for

  9. Metabolism and elimination of methyl, iso- and n-butyl paraben in human urine after single oral dosage.

    Science.gov (United States)

    Moos, Rebecca K; Angerer, Jürgen; Dierkes, Georg; Brüning, Thomas; Koch, Holger M

    2016-11-01

    Parabens are used as preservatives in personal care and consumer products, food and pharmaceuticals. Their use is controversial because of possible endocrine disrupting properties. In this study, we investigated metabolism and urinary excretion of methyl paraben (MeP), iso-butyl paraben (iso-BuP) and n-butyl paraben (n-BuP) after oral dosage of deuterium-labeled analogs (10 mg). Each volunteer received one dosage per investigated paraben separately and at least 2 weeks apart. Consecutive urine samples were collected over 48 h. In addition to the parent parabens (free and conjugated) which are already used as biomarkers of internal exposure and the known but non-specific metabolites, p-hydroxybenzoic acid (PHBA) and p-hydroxyhippuric acid (PHHA), we identified new, oxidized metabolites with hydroxy groups on the alkyl side chain (3OH-n-BuP and 2OH-iso-BuP) and species with oxidative modifications on the aromatic ring. MeP represented 17.4 % of the dose excreted in urine, while iso-BuP represented only 6.8 % and n-BuP 5.6 %. Additionally, for iso-BuP, about 16 % was excreted as 2OH-iso-BuP and for n-BuP about 6 % as 3OH-n-BuP. Less than 1 % was excreted as ring-hydroxylated metabolites. In all cases, PHHA was identified as the major but non-specific metabolite (57.2-63.8 %). PHBA represented 3.0-7.2 %. For all parabens, the majority of the oral dose captured by the above metabolites was excreted in the first 24 h (80.5-85.3 %). Complementary to the parent parabens excreted in urine, alkyl-chain-oxidized metabolites of the butyl parabens are introduced as valuable and contamination-free biomarkers of exposure.

  10. Response of the antioxidant defense system to tert-butyl hydroperoxide and hydrogen peroxide in a human hepatoma cell line (HepG2).

    Science.gov (United States)

    Alía, Mario; Ramos, Sonia; Mateos, Raquel; Bravo, Laura; Goya, Luis

    2005-01-01

    The aim of this work was to investigate the response of the antioxidant defense system to two oxidative stressors, hydrogen peroxide and tert-butyl hydroperoxide, in HepG2 cells in culture. The parameters evaluated included enzyme activity and gene expression of superoxide dismutase, catalase, glutathione peroxidase, and activity of glutathione reductase. Besides, markers of the cell damage and oxidative stress evoked by the stressors such as cell viability, intracellular reactive oxygen species generation, malondialdehyde levels, and reduced glutathione concentration were evaluated. Both stressors, hydrogen peroxide and tert-butyl hydroperoxide, enhanced cell damage and reactive oxygen species generation at doses above 50 microM. The concentration of reduced glutathione decreased, and levels of malondialdehyde and activity of the antioxidant enzymes consistently increased only when HepG2 cells were treated with tert-butyl hydroperoxide but not when hydrogen peroxide was used. A slight increase in the gene expression of Cu/Zn superoxide dismutase and catalase with 500 microM tert-butyl hydroperoxide and of catalase with 200 microM hydrogen peroxide was observed. The response of the components of the antioxidant defense system evaluated in this study indicates that tert-butyl hydroperoxide evokes a consistent cellular stress in HepG2.

  11. Synthesis, characterization and investigation of catalytic activity of Cu1−CoFe2O4 nanocatalysts in -butylation of -cresol

    Indian Academy of Sciences (India)

    Reza Fareghi Alamdari; Zahra Hosseinabadi; Masoud Farhadi Khouzani

    2012-07-01

    In this work, tertiary butylation of -cresol was carried out in the presence of Cu1−CoFe2O4 (x = 0 to 1) nanocatalysts by employing methyl-tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) as alkylation agents. Effects of temperature, mole ratio, type and catalyst composition, time and solvent in reaction conditions were investigated. These nanocatalysts were synthesized using hydrothermal method. The characterization of these catalysts was investigated by means of X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FT-IR). These nanocatalysts can be recovered and recycled. A good correlation was found between the activity, in terms of -cresol conversion and various product selectivities for this reaction, and also the acid-base properties of the catalysts. Nano-sized Cu0.5Co0.5Fe2O4, in comparison to the other nanocatalysts discussed in this report is the most active nanocatalyst. The only product of this reaction is 2--butyl -cresol with selectivity of 100% and -cresol conversion is 70%. The possible mechanism for this reaction system was discussed based on the reaction results. The reaction mechanism proposed involves the interaction of phenoxide from phenol and the tert-butyl cation from isobutene on Cu1−CoFe2O4.

  12. Generation of free radicals from organic hydroperoxide tumor promoters in isolated mouse keratinocytes. Formation of alkyl and alkoxyl radicals from tert-butyl hydroperoxide and cumene hydroperoxide.

    Science.gov (United States)

    Taffe, B G; Takahashi, N; Kensler, T W; Mason, R P

    1987-09-05

    The organic hydroperoxides tert-butyl hydroperoxide and cumene hydroperoxide are tumor promoters in the skin of SENCAR mice, and this activity is presumed to be mediated through the activation of the hydroperoxides to free radical species. In this study we have assessed the generation of free radicals from organic hydroperoxides in the target cell (the murine basal keratinocyte) using electron spin resonance. Incubation of primary isolates of keratinocytes from SENCAR mice in the presence of spin traps (5,5-dimethyl-1-pyrroline N-oxide or 2-methyl-2-nitrosopropane) and either tert-butyl hydroperoxide or cumene hydroperoxide resulted in the generation and detection of radical adducts of these spin traps. tert-Butyl alkoxyl and alkyl radical adducts of 5,5-dimethyl-1-pyrroline N-oxide were detected shortly after addition of tert-butyl hydroperoxide, whereas only alkyl radical adducts were observed with cumene hydroperoxide. Spin trapping of the alkyl radicals with 2-methyl-2-nitrosopropane led to the identification of methyl and ethyl radical adducts following both tert-butyl hydroperoxide and cumene hydroperoxide exposures. Prior heating of the cells to 100 degrees C for 30 min prevented radical formation. The radical generating capacity of subcellular fractions of these epidermal cells was examined using 5,5-dimethyl-1-pyrroline N-oxide and cumene hydroperoxide, and this activity was confined to the 105,000 X g supernatant fraction.

  13. tert-Butyl N-[6-(N,N-dipropylcarbamoyl-1,3-benzothiazol-2-yl]carbamate

    Directory of Open Access Journals (Sweden)

    Xin Fang

    2010-05-01

    Full Text Available The title compound C19H27N3O3S, crystallizes with two unique molecules in the asymmetric unit. The benzene ring of each benzothiazole unit carries a dipropylcarbamoyl substituent in the 6-position and a tert-butyl carbamate unit on each thiazole ring. In the crystal structure, intermolecular N—H...N and weak C—H...O hydrogen bonds form centrosymmetric dimers. Additional C—H...O contacts construct a three-dimensional network. A very weak C—H...π contact is also present.

  14. HYDROLYSIS TRANSFORMATION OF A POLYSTYRENE-b-POLY(tert-BUTYL ACRYLATE)COPOLYMER AND MICELLIZATION PROPERTIES OF THE HYDROLYZED COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A very mild and extremely efficient hydrolysis method for transformation of polystyrene-b-poly(tert-butyl acrylate) (PS-b-PtBA) to polystyrene-b-poly(acrylic acid) (PS-b-PAA)was designed and carried out using more convenient and inexpensive chlorotrimethylsilane/sodium iodide as reagents. The hydrolysis product can self-assemble in aqueous media to give regular micelles with PS block forming the core and PAL4 block forming the corona, or in tetrahydrofuran (THF) to give reverse micelles with the hydrophilic block in the core.

  15. Role of intravenously administered hyoscine butyl bromide in retrograde terminal ileoscopy: A randomized, double-blinded, placebo-controlled trial

    Institute of Scientific and Technical Information of China (English)

    SP Misra; M Dwivedi

    2007-01-01

    AIM:To evaluated the role of hyoscine butyl bromide in facilitating retrograde ileoscopy.METHODS:Retrograde terminal ileoscopy was attempted in 200 consecutive patients undergoing colonoscopy. After intubation of the cecum and visualization of the ileocecal valve,butyl bromide injection or normal saline was given intravenously to the patients in a double blind random fashion. The pulse rate and oxygen saturation were measured continuously. After completion of the procedure,endoscopists were then asked to score the ease of intubation and the ease of visualization of the terminal ileum on a visual scale of 1 to 10. The patients were also asked to score the pain after receiving hyoscine butyl bromide injection on a score of 1 to 10.RESULTS:Terminal ileoscopy could be performed in 188 patients. The mean (SD) visual analogue score for the ease of intubation of the cecum was 7.4 (0.65) in the injection group and 5.9 (0.8) in the placebo group (P<0.001). The mean (SD) length of ileum visualized in the injection group was 14.4 (3.3) cm and 10.4 (2.7) cm in the placebo group (P<0.001). The mean (SD) visual analogue score for ease of visualization of the terminal ileum was 7.5 (0.69) in the injection group and 5.9 (0.7) in the placebo group (P<0.001). The pain score experienced by the patients was 6.5 (0.7) in the injection group and 6.7 (0.69) in the placebo group (P<0.008). Although the pulse rate increased significantly in patients receiving the drug,no statistically significant difference was noted in the oxygen saturation between the two groups either before or after administration of the drug. No complications were observed in either of the groups.CONCLUSION:Hyoscine butyl bromide injection is a useful adjunct in helping the intubation and visualizationof terminal ileum during colonoscopy.

  16. Effect of antioxidant tertiary butyl hydroquinone on the thermal and oxidative stability of sesame oil (sesamum indicum) by ultrasonic studies

    OpenAIRE

    Prasad, N; Siddaramaiah, Basavarajaiah; Banu, Mujeeda

    2014-01-01

    The aim of the current investigation is to evaluate the efficiency of tertiary butyl hydroquinone (TBHQ) as an antioxidant in sesame oil (sesamum indicum) by density, viscosity and ultrasonic velocity. The effects of varying amounts of TBHQ on the oxidation stability of sesame oil have been investigated. The antioxidant incorporated sesame oil system and control edible oil were subjected to heating at 180 ± 5 °C continuously for a period of 4 h per day for consecutive 4 days. The parameters u...

  17. Effect of antioxidant butylated hydroxyl anisole on the thermal or oxidative stability of sunflower oil (Helianthus Annuus) by ultrasonic

    OpenAIRE

    Murari, Satish Kumar; Shwetha, M. V.

    2015-01-01

    The aim of the current investigation was to evaluate the efficiency of butylated hydroxyl anisole (BHA) as an antioxidant in sunflower oil (Helianthus Annuus). The oxidation stability of sunflower oil have been investigated by the effects of varying amounts of BHA. The antioxidant incorporated sunflower oil system and control edible oil were subjected to heating at 180 ± 5 °C continuously for a period of 4 h per day for consecutive 4 days. The parameters used to assess the thermal degradation...

  18. Synthesis and chemical behaviour of 17a-butyl-3b,17b-dihydroxy-16-oximino-5-androstene (NOTE

    Directory of Open Access Journals (Sweden)

    KATARINA PENOV GASI

    2001-01-01

    Full Text Available Starting from 3b-hydroxy-16-oximino-5-androsten-17-one (1, the recently synthesized 16-oximino-17b-hydroxy-17a-butyl derivative 2 gave by the Beckmann fragmentation reaction with titanium(III chloride or p-toluenesulphonyl chloride the corresponding D-seco derivative 3. However, using acetic anhydride, in addition to the 3b-acetoxy D-seco derivative 4, the 17-aza D-homo derivative 5 was obtained. The structure of compound was proposed on the basis of NMR-spectroscopy.

  19. HYDROLYSIS TRANSFORMATION OF A POLYSTYRENE—b—POLY(tert—BUTYL ACRYLATE) COPOLYMER AND MICELLIZATION PROPERTIES OF THE HYDROLYZED COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    SIZhihuai; LIHexian; 等

    2001-01-01

    A very mild and extremely efficient hydrolysis method for transformation of polystyrene-b-poly(tert-butyl acrylate)(PS-b-PtBA)to polystyrene-b-poly(acrylic acid)(PS-b-PAA) was designed and carried out using more convenient and inexpensive chlorotrimethylsilane/sodium iodide as reagents.The hydrolysis product can self-assemble in aqueous media to give regular micelles with PS block forming the core and PAA block forming the corona,or in tetrahydrofuran (THF) to give reverse micelles with the hydrophilic block in the core.

  20. 1-Butyl-3-methylimidazolium Salts as New Catalysts to Produce Epoxy-anhydride Polymers with Improved Properties

    Directory of Open Access Journals (Sweden)

    Mikhail S. Fedoseev

    2014-01-01

    Full Text Available We report the curing process of epoxy oligomers by using isomethyltetrahydrophthalic anhydride catalyzed with 1-butyl-3-methylimidazolium salts. Catalytic action has been ascertained to be dependent on the nature of anion. Salts with (Br- and (PO4- anions appeared to be most active. Formation of salt adducts with epoxy resin and anhydride is shown. Polymers having higher values of strength and glass transition temperature—as compared with similar epoxy systems cured in the presence of tertiary amines as catalysts—are prepared.

  1. STABILITY OF EMULSIFIER-FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE/ BUTYL ACRYLATE/SODIUM MONO(ETHYL POLYOXYETHYLENE) MALEATE

    Institute of Scientific and Technical Information of China (English)

    Mao-gen Zhang; Zhi-xue Weng; Zhi-ming Huang; Zu-ren Pan

    1999-01-01

    A series of new water-soluble bifunctional comonomers having both carboxyl and alkyl polyoxyethylene groups, such as sodium mono(ethyl polyoxyethylene) maleate (ZE series) with various molecular weights of polyoxyethylene ethyl ether, were synthesized and characterized. The effects of the structural factor, the amount and feeding mode of the comonomers, the initiator concentration and polymerization temperature on the stability of emulsifier-free emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate (BA) in the presence of a small amount of ZE with potassium persulfate as initiator were investigated. Stable, almost monodispersed MMA/BA/ZE emulsifier-free latex particles were prepared.

  2. Di-n-butyl phthalate causes estrogenic effects in adult male Murray rainbowfish (Melanotaenia fluviatilis).

    Science.gov (United States)

    Bhatia, Harpreet; Kumar, Anupama; Ogino, Yukiko; Gregg, Adrienne; Chapman, John; McLaughlin, Mike J; Iguchi, Taisen

    2014-04-01

    Phthalic acid esters (PAEs) are a class of synthetic industrial chemicals commonly found in the aquatic environment worldwide. PAEs have been recognised as anti-androgens in male mammals but little is known about their endocrine disrupting effects in fish. This study investigated the effects of 7-day exposures to nominal (measured) concentrations of 125 (62), 250 (140), 500 (230) and 1,000 (383) μg/L of di-n-butyl phthalate (DnBP) on the biomarkers of reproduction in adult male Murray River rainbowfish (Melanotaenia fluviatilis) using molecular, biochemical and histological endpoints. None of the tested concentrations of DnBP had any effect on survival or the vital body indices of the fish. The sizes of spermatogonia, Type A and B spermatocytes and spermatids were significantly smaller relative to the controls after treatment with DnBP. This was accompanied by a significant increase in the proportion of spermatogonia in fish treated with 250-1,000 μg/L of DnBP in comparison to the unexposed fish. At the end of the exposure period, the expressions of the transcripts for the androgen receptors α and β were significantly elevated in the livers of the fish treated with 500 and 1,000 μg/L of DnBP. In addition, there was also an increase in the circulating concentrations of vitellogenin in the plasma in the higher treatment groups. An induction in the activity of aromatase was noted in the brains of 1,000 μg/L DnBP-treated fish. This was accompanied by an increase in the hepatic expression of the genes (here and later, whenever the phrase gene expression is used as a synonym for gene transcription although it is acknowledged that it is also regulated, e.g., by translation, mRNA stability and protein stability) encoding for the oestrogen receptors α and β and choriogenin L. Collectively, an increase in the proportion of spermatogonia in the testes, the upregulation of the genes for the oestrogen receptors and choriogenin in the liver, an induction in the brain

  3. Preparation of Seeding Type Immobilized Microorganisms and Their Degradation Characteristics on Di-n-Butyl Phthalate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To study the preparation of seeding type immobilized microorganisms and their degradation characteristics on di-n-butyl phthalate (DBP). Methods Diatomite, clinoptilolite, silk zeolite, and coal fly ash were chosen as reserved materials and modified. Their adsorption capacity and intensity in the bacteria were determined and the best carrier was picked out. The seeding type immobilized microorganisms were prepared by the best carrier and then it degraded DBP under different primary concentration, vibration rate, pH, temperature in the presence of metal compounds. Results The adsorption capacity of the modified coal fly ash, silk zeolite, clinoptilolite and zeolite was 44.2%, 71.6%, 84.0%, and 94.4%, respectively, which was 1.66, 1.49, 1.37, and 1.16 times as high as that of their natural state. Their adsorption intensity was 72.1%, 90.5%, 90.1%,and 91.1% in turn. The modified diatomite was selected to prepare the seeding type immobilized microorganisms. When the primary DBP concentration was 100 to 500 mg/L, the DBP-degraded rate of the immobilized microorganisms could be above 80%. The degradation activity of both the dissociative and immobilized microorganisms was higher in vibration than in stillness.When pH was 6.0 to 9.0, the DBP-degraded rate of the immobilized microorganisms was above 82%, which was higher than the dissociative microorganisms. When the temperature was between 20℃ and 40℃, the DBP-degraded rate could reach 84.5% in 24 h. The metal compounds could inhibit the degradation activity of both the dissociative and immobilized microorganisms. The degradation process of the immobilized microorganisms could be described by the first-order model.Conclusion The adsorption capacity of the diatomite, clinoptilolite, silk zeolite and coal fly ash on DBP-degrading bacteria can be improved obviously after they are modified. The modified diatomite is best in terms of its adsorption capacity and intensity. Its seeding type immobilized microorganisms could

  4. 甲苯与叔丁醇在补铝HM沸石催化剂上的烷基化反应%Tert-butylation of toluene with tert-butyl alcohol over realuminated H-mordenite zeolite

    Institute of Scientific and Technical Information of China (English)

    周志伟; 武文良; 王军; 曾崇余

    2009-01-01

    The realuminated H-mordenite catalysts(HM1-4)treated with difirerent concentrations of NaOH and NaAlO2 aqueous solutions were prepared,and characterized by inductively coupled plasma(ICP),X-ray diffraction (XRD),Fourier transform-infrared spectroscopy(FT-I R)and temperature-programmed desorption of ammonia,They are of lower Si/Al ratio and higher acid amount while keeping a high relative crystallinity.Their catalytic performances were evaluated with the liquid-phase tert-butylation of toluene with tert-butyl alcohol in a 100 ml stainless steel batch reactor equipped with a stirrer.HM2 zeolite catalyst,obtained by treating HM in 0.1 mol.L-1 NaOH followed bv 0.05 mol.L-1 NaAIO2 aqueous solution,shows a higher catalytic activity because of its highest acid amount.For HM2 catalyst the influcnces of reaction conditions on catalytic perfclrmance were investigated.The conversion of toluene iS 50.3%and the selectivity of p-tert-butyrltoluene is 74.7%at a temperature of 180°C,2 of molar ratio of tert-butyI alcohol to toluene.4h of reaction time and 0.2 of M(catalyst)/M(toluene).

  5. Vapor intrusion risk of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME) and ethyl tert-butyl ether (ETBE): A modeling study.

    Science.gov (United States)

    Ma, Jie; Xiong, Desen; Li, Haiyan; Ding, Yi; Xia, Xiangcheng; Yang, Yongqi

    2017-06-15

    Vapor intrusion of synthetic fuel additives represents a critical yet still neglected problem at sites contaminated by petroleum fuel releases. This study used an advanced numerical model to investigate the vapor intrusion potential of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), and ethyl tert-butyl ether (ETBE). Simulated indoor air concentration of these compounds can exceed USEPA indoor air screening level for MTBE (110μg/m(3)). Our results also reveal that MTBE has much higher chance to cause vapor intrusion problems than TAME and ETBE. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the vertical screening criteria for petroleum hydrocarbons may not provide sufficient protectiveness for fuel additives, and ether oxygenates in particular. In addition to adverse impacts on human health, ether oxygenate vapor intrusion may also cause aesthetic problems (i.e., odour and flavour). Overall, this study points out that ether oxygenates can cause vapor intrusion problems. We recommend that USEPA consider including the field measurement data of synthetic fuel additives in the existing PVI database and possibly revising the PVI Guidance as necessary.

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

    Science.gov (United States)

    Scibetta, Licia; Campo, Laura; Mercadante, Rosa; Foà, Vito; Fustinoni, Silvia

    2007-01-02

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

  7. Single-walled carbon nanotubes as an effective adsorbent in solid-phase microextraction of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether from human urine.

    Science.gov (United States)

    Rastkari, Noushin; Ahmadkhaniha, Reza; Yunesian, Masud

    2009-05-15

    Carbon nanotubes (CNTs) are a kind of new carbon-based nano-materials which have drawn great attention in many application fields. The potential single-walled carbon nanotubes (SWCNTs) as solid-phase microextraction (SPME) adsorbents for the preconcentration of environmental pollutants have been investigated in recent years. The goal of this work was to investigate the feasibility of SWCNTs used as adsorbents for solid-phase microextraction of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) in human urine. SWCNTs were attached onto a stainless steel wire through organic binder. Potential factors affecting the extraction efficiency were optimized, including extraction time, extraction temperature, desorption time, desorption temperature, and salinity. The developed method showed good performance according to the ICH performance criteria for bioanalytical methods. The calibration curves of the ethers were linear (r(2)>or=0.992) in the range from 10 to 5000 ng L(-1). The limits of detection at a signal-to-noise (S/N) ratio of 3 were 10 ng L(-1) for all the analytes. In addition, compared with the commercial carboxen/polydimethylsiloxane (CAR/PDMS) fiber, the SWCNT fiber showed better thermal stability (over 350 degrees C) and longer life span (over 150 times). The developed method was applied successfully to determine trace level of the ethers in urine of 10 healthy male volunteers.

  8. Catalytic Synthesis of Tert-Butyl Acetate by Nd2O3/Al2O3-Nd2O3/ZnO

    Institute of Scientific and Technical Information of China (English)

    Wang Yajun; Han Limin; A Shan

    2007-01-01

    Nd2O3 was used to support Al2O3 and ZnO to prepare a supported solid base catalyst and investigate the effect of catalyst and reaction conditions on the synthesis of tert-butyl acetate. The composited oxide of Nd2O3/Al2O3-Nd2O3/ZnO exhibited excellent catalytic activity for the synthsis of tert-butyl acetate. The molar ratio of tert-butanol to acetic anhydride is 3:1, the catalyst in total amount of reactant nearly 0.5%, and reaction time 6 h. With the above conditions, yield of the reaction could reach to 65%. The structure of product were verified by the FT-IR, Element analysis, and MS, which proved that the product was tert-butyl acetate.

  9. The Emulsion Polymerization of Each of Vinyl Acetate and Butyl Acrylate Monomers Using bis (2-ethylhexyl Maleate for Improving the Physicomechanical Properties of Paints and Adhesive Films

    Directory of Open Access Journals (Sweden)

    K. A. Shaffei

    2009-01-01

    Full Text Available Improving the water sensitivity of polyvinyl acetate PVAc films as well as pressure sensitivity, adhesion and washability of polybutyl acrylate were achieved by using bis (2-ethylhexyl maleate (BEHM. The emulsion polymerization kinetics of vinyl acetate and butyl acrylate in presence of BEHM was studied. The order of the polymerization reaction with respect to the BEHM in presence of each of vinyl acetate and butyl acrylate was studied. The physicomechanical properties of the polyvinyl acetate films and vinyl acetate-butyl acrylate copolymer films were studied in presence of BEHM and the obtained results were matched with those prepared in the presence of pluronic F 108 and showed superior values. The obtained mean average molecular weights were found to be smaller in presence of BEHM assuring the presence of chain transfer reaction.

  10. Thermolytic 4-methylthio-1-butyl group for phosphate/thiophosphate protection in solid-phase synthesis of DNA oligonucleotides.

    Science.gov (United States)

    Cieślak, Jacek; Grajkowski, Andrzej; Livengood, Victor; Beaucage, Serge L

    2004-04-02

    The thermolabile 4-methylthio-1-butyl phosphate/thiophosphate protecting group for DNA oligonucleotides has been investigated for its potential application to a "heat-driven" process for either oligonucleotide synthesis on diagnostic microarrays or, oppositely, to the large-scale preparation of therapeutic oligonucleotides. The preparation of phosphoramidites 10a-d is straightforward, and the incorporation of these amidites into oligonucleotides via solid-phase techniques proceeds as efficiently as that achieved with 2-cyanoethyl deoxyribonucleoside phosphoramidites. The versatility of the 4-methylthio-1-butyl phosphate/thiophosphate protecting group is exemplified by its facile removal from oligonucleotides upon heating for 30 min at 55 degrees C in an aqueous buffer under neutral conditions or within 2 h at 55 degrees C in concentrated NH(4)OH. The deprotection reaction occurs through an intramolecular cyclodeesterification mechanism leading to the formation of sulfonium salt 18. When mixed with deoxyribonucleosides and N-protected 2'-deoxyribonucleosides or with a model phosphorothioate diester under conditions approximating those of large-scale (>50 mmol) oligonucleotide deprotection reactions, the salt 18 did not significantly alter DNA nucleobases or desulfurize the phosphorothioate diester model to an appreciable extent.

  11. Experimental determination and prediction of phase behavior for 1-butyl-3-methylimidazolium nonafluorobutyl sulfonate and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Soon Kang; Park, YoonKook [Hongik University, Sejong (Korea, Republic of); Pore, Dattaprasad Marutrao [Shivaji University, Kolhapur (India)

    2014-09-15

    The vapor-liquid equilibrium of the binary system CO{sub 2}+1-butyl-3-methylimidazolium nonafluorobutyl sulfonate ([BMIM][NfO]) was measured over a temperature range of 298.2-323.2 K at intervals of 5.0 K for CO{sub 2} mole fraction ranging from 0.137 to 0.900 using a high-pressure variable-volume view cell. The Peng-Robinson equation of state was then applied with two-parameter mixing rules over the same range and the results compared with the experimentally obtained data. Increasing the alkyl chain length in perfluorinated sulfonate from methyl to butyl markedly increased the CO{sub 2} solubility. To investigate the effect of the number of fluorine atoms in the anion on the phase behavior of imidazolium based ionic liquid, these experimental results were then compared with those reported in previous experimental studies of 1-alkyl-3-methylimidazolium cations and with modeling data. It looks likely that both the number of fluorine atoms in the anion and the presence of S=O groups play an important role in designing CO{sub 2}-philic molecules.

  12. Butylated Hydroxyanisole Blocks the Occurrence of Tumor Associated Macrophages in Tobacco Smoke Carcinogen-Induced Lung Tumorigenesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan; Choksi, Swati; Liu, Zheng-Gang, E-mail: zgliu@helix.nih.gov [Cell and Cancer Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States)

    2013-12-04

    Tumor-associated macrophages (TAMs) promote tumorigenesis because of their proangiogenic and immune-suppressive functions. Here, we report that butylated hydroxyanisole (BHA) blocks occurrence of tumor associated macrophages (TAMs) in tobacco smoke carcinogen-induced lung tumorigenesis. Continuous administration of butylated hydroxyanisole (BHA), a ROS inhibitor, before or after NNK treatment significantly blocked tumor development, although less effectively when BHA is administered after NNK treatment. Strikingly, BHA abolished the occurrence of F4/80{sup +} macrophages with similar efficiency no matter whether it was administered before or after NNK treatment. Detection of cells from bronchioalveolar lavage fluid (BALF) confirmed that BHA markedly inhibited the accumulation of macrophages while slightly reducing the number of lymphocytes that were induced by NNK. Immunohistological staining showed that BHA specifically abolished the occurrence of CD206{sup +} TAMs when it was administered before or after NNK treatment. Western blot analysis of TAMs markers, arginase I and Ym-1, showed that BHA blocked NNK-induced TAMs accumulation. Our study clearly demonstrated that inhibiting the occurrence of TAMs by BHA contributes to the inhibition of tobacco smoke carcinogen-induced tumorigenesis, suggesting ROS inhibitors may serve as a therapeutic target for treating smoke-induced lung cancer.

  13. Biodegradation of methyl tert-butyl ether by cometabolism with hexane in biofilters inoculated with Pseudomonas aeruginosa.

    Science.gov (United States)

    Salazar, Margarita; Morales, Marcia; Revah, Sergio

    2012-01-01

    Biodegradation of methyl tert-butyl ether (MTBE) vapors by cometabolism with gaseous hexane (n-hexane > 95%) was investigated using Pseudomonas aeruginosa utilizing short chain aliphatic hydrocarbon (C(5)-C(8)). Kinetic batch experiments showed that MTBE was degraded even when hexane was completely exhausted with a cometabolic coefficient of 1.06 ± 0.16 mg MTBE mg hexane(-1). Intermediate tert-butyl alcohol (TBA) accumulation was observed followed by its gradual consumption. A maximum MTBE elimination capacity (EC(MAX)) of 35 g m(-3) h(-1) and removal efficiency (RE) of 70% were attained in mineral medium amended biofilters having an empty bed residence time (EBRT) of 1 min. For these experimental conditions, a maximum hexane EC of approximately 60 g m(-3) h(-1) was obtained at a load of 75 g m(-3) h(-1). Experiments under transient conditions revealed a competitive substrate interaction between MTBE and hexane. Biomass densities between 5.8 and 12.6 g L(biofilter) (-1) were obtained. Nevertheless, production of biopolymers caused non-uniform distribution flow rates that reduced the performance. Residence time distribution profiles showed an intermediate dispersion flow rate with a dispersion coefficient of 0.8 cm(2) s(-1).

  14. Investigation of emissions characteristics of secondary butyl alcohol-gasoline blends in a port fuel injection spark ignition engine

    Directory of Open Access Journals (Sweden)

    Yusri I.M.

    2017-01-01

    Full Text Available Exhaust emissions especially from light duty gasoline engine are a major contributor to air pollution due to the large number of vehicles on the road. The purpose of this study is to experimentally analyse the exhaust pollutant emissions of a four-stroke port fuel spark ignition engines operating using secondary butyl alcohol–gasoline blends by percentage volume of 5% (GBu5, 10% (GBu10 and 15% (GBu15 of secondary butyl- alcohol (2-butanol additives in gasoline fuels at 50% of wide throttle open. The exhaust emissions characteristics of the engine using blended fuels was compared to the exhaust emissions of the engine with gasoline fuels (G100 as a reference fuels. Exhaust emissions analysis results show that all of the blended fuels produced lower CO by 8.6%, 11.6% and 24.8% for GBu5, GBu10 and GBu15 respectively from 2500 to 4000 RPM, while for HC, both GBu10 and GBu15 were lower than that G100 fuels at all engine speeds. In general, when the engine was operated using blended fuels, the engine produced lower CO and HC, but higher CO2.

  15. Study of interaction of butyl p-hydroxybenzoate with human serum albumin by molecular modeling and multi-spectroscopic method

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qin, E-mail: wqing07@lzu.c [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Zhang Yaheng, E-mail: zhangyah04@lzu.c [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Sun Huijun, E-mail: sun.hui.jun-04@163.co [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen Hongli, E-mail: hlchen@lzu.edu.c [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen Xingguo, E-mail: chenxg@lzu.edu.c [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China)

    2011-02-15

    Study of the interaction between butyl p-hydroxybenzoate (butoben) and human serum albumin (HSA) has been performed by molecular modeling and multi-spectroscopic method. The interaction mechanism was predicted through molecular modeling first, then the binding parameters were confirmed using a series of spectroscopic methods, including fluorescence spectroscopy, UV-visible absorbance spectroscopy, circular dichroism (CD) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. The thermodynamic parameters of the reaction, standard enthalpy {Delta}H{sup 0} and entropy {Delta}S{sup 0}, have been calculated to be -29.52 kJ mol{sup -1} and -24.23 J mol{sup -1} K{sup -1}, respectively, according to the Van't Hoff equation, which suggests the van der Waals force and hydrogen bonds are the predominant intermolecular forces in stabilizing the butoben-HSA complex. Results obtained by spectroscopic methods are consistent with that of the molecular modeling study. In addition, alteration of secondary structure of HSA in the presence of butoben was evaluated using the data obtained from UV-visible absorbance, CD and FT-IR spectroscopies. - Research highlights: The interaction between butyl p-hydroxybenzoate with HSA has been investigated for the first time. Molecular modeling study can provide theoretical direction for experimental design. Multi-spectroscopic method can provide the binding parameters and thermodynamic parameters. These results are important for food safety and human health when using parabens as a preservative.

  16. Healing of periodontal flaps when closed with silk sutures and N-butyl cyanoacrylate: A clinical and histological study

    Directory of Open Access Journals (Sweden)

    Kulkarni Sudhindra

    2007-01-01

    Full Text Available Background: The closure of the periodontal flaps post-surgery is a necessity for attainment of a primary union between the flap margins and the establishment of a healthy dentogingival junction. N-butyl cyanoacrylate is a tissue adhesive, which can be used for the closure of the incised wounds to overcome the problems associated with conventional suture materials like silk. Objective: The present study was carried out to assess the healing of the periodontal flaps when closed with the conventional silk sutures and N-butyl cyanoacrylate. Materials and Methods: The study was carried out on 24 patients who needed flap surgical procedure for pocket therapy. Results: It was found that healing with the cyanoacrylate is associated with less amount of inflammation during the first week when compared with silk. However, over a period of 21 days to 6 weeks, the sites treated with both the materials showed similar healing patterns. Conclusion: It can be concluded that cyanoacrylate aids in early initial healing.

  17. Enhanced cometabolic degradation of methyl tert-butyl ether by a Pseudomonas sp. strain grown on n-pentane

    Science.gov (United States)

    Li, S. S.; Wang, S.; Yan, W.

    2016-08-01

    When methyl tert-butyl ether (MTBE) is added as oxygenates it increases the octane number and decreases the release of nitric oxide from the incomplete combustion of reformulated gasoline. The extensive use of MTBE allowed it to be detectable as a pollutant in both ground-level and underground water worldwide. The present study focuses on the isolation and characterization of MTB-degrading microorganisms by cometabolism based on the results of growth on different carbon sources. It also focuses on the kinetic analysis and the continuous degradation of MTBE. A bacterial strain WL1 that can grow on both n-alkanes (C5-C8) and aromatics was isolated and named Pseudomonas sp. WL1 according to the 16S rDNA sequencing analysis. Strain WL1 could cometabolically degrade MTBE in the presence of n-alkanes with a desirable degradation rate. Diverse n-alkanes with different lengths of carbon chains showed significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA). When strain WL1 cometabolically degraded MTBE in the presence of n-pentane, higher MTBE-degrading rate and lower TBA-accumulation were observed (Vmax = 38.1 nmol/min/mgprotei, Ks = 6.8 mmol/L). In the continuous degrading experiment, the removal efficiency of MTBE by Pseudomonas sp. WL1 did not show any obvious decrease after five subsequent additions.

  18. SYNTHESIS OF POLYACRYLAMIDE WITH PENDANT POLY(BUTYL ACRYLATE) CHAINS USING THE MACROMER TECHNIQUE AND STUDIES ON THEIR PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Hong-quan Xie; Gui-ying Liao; Yu Gao

    2004-01-01

    An amphiphilic graft polymer, (PAM-g-PBA), polyacrylamide (PAM) having poly(n-butyl acrylate) (PBA) side chains, was obtained by radical copolymerization of acrylamide with PBA macromer in solution. The macromer was synthesized by free radical polymerization of butyl acrylate in the presence of different amounts of thioglycolic acid as the chain transfer agent, followed by termination with glycidyl methacrylate. The reactivity ratio and effects of copolymerization conditions on the conversion of macromer or grafting efficiency were studied. The crude products were purified by extraction with toluene and water successively. Thc purified graft copolymer was characterized by IR, DSC and TEM. PAM-g-PBA can bring about microphase separation and exhibits good emulsifying properties and water absorbency. PAM-g-PBA exhibits a very good compatibilizing effect on the acrylic rubber/poly(vinyl chloride) blends. 2%-3% of the graft copolymer is enough for enhancing the tensile strength of the blends. The tensile strength of the blends is more than twice that without the compatibilizer. DSC and SEM demonstrated the enhancement of compatibility in the presence of the graft copolymer.

  19. Preparation of l-butyl-3-methylimidazolium dodecatungstophosphate and its. catalytic performance for esterification of ethanol and acetic acid

    Institute of Scientific and Technical Information of China (English)

    Jiehua SHI; Gao PAN

    2009-01-01

    l-Butyl-3-methylimidazolium dodecatungstophosphate catalyst ([bmim]3PW12040) with high water tolerance was prepared from l-butyl-3-methylimidazolium bromide ([bmim]Br) and phosphotungstic acid (H3PW12O40). The catalyst was characterized by means of Fourier transform infrared spectroscopy, thermogravi-metry-differential scanning calorimetry, n-BuNH2 poten-tiometric titration, elemental analysis and so on. Its catalytic activity for esterification of ethanol and acetic acid to ethyl acetate was measured. The results show that there were three crystal-water molecules in the [bmim]3PW12040 catalyst, and it preserved the primary Keggin structure and acid strength of H3PW12O40. The acid amount of [bmim]3PW12O40 catalyst was less than that of H3PW12O40. The [bmim]3PW12O40 catalyst exhibited higher catalytic activity and reusability in the esterification of ethanol and acetic acid to ethyl acetate.

  20. Synthesis and pharmacological evaluation of 1-alkyl-N-[2-ethyl-2-(4-fluorophenyl)butyl]piperidine-4-carboxamide derivatives as novel antihypertensive agents.

    Science.gov (United States)

    Watanuki, Susumu; Matsuura, Keisuke; Tomura, Yuichi; Okada, Minoru; Okazaki, Toshio; Ohta, Mitsuaki; Tsukamoto, Shin-Ichi

    2011-09-15

    We synthesized and evaluated inhibitory activity against T-type Ca(2+) channels for a series of 1-alkyl-N-[2-ethyl-2-(4-fluorophenyl)butyl]piperidine-4-carboxamide derivatives. Structure-activity relationship studies have revealed that dialkyl substituents at the benzylic position play an important role in increasing inhibitory activity. Oral administration of N-[2-ethyl-2-(4-fluorophenyl)butyl]-1-(2-phenylethyl)piperidine-4-carboxamide (20d) lowered blood pressure in spontaneously hypertensive rats without inducing reflex tachycardia, which is often caused by traditional L-type Ca(2+) channel blockers.

  1. Dosimetric measurements of an n-butyl cyanoacrylate embolization material for arteriovenous malformations

    Energy Technology Data Exchange (ETDEWEB)

    Labby, Zacariah E., E-mail: zelabby@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin–Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Chaudhary, Neeraj [Division of Neurointerventional Radiology, Departments of Radiology and Neurosurgery, University of Michigan Hospital and Health Systems, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109 (United States); Gemmete, Joseph J. [Division of Neurointerventional Radiology, Departments of Radiology, Neurosurgery, and Otolaryngology, University of Michigan Hospital and Health Systems, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109 (United States); Pandey, Aditya S. [Department of Neurosurgery, University of Michigan Hospital and Health Systems, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109 (United States); Roberts, Donald A. [Radiation Physics Division, Department of Radiation Oncology, University of Michigan Hospital and Health Systems, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109 (United States)

    2015-04-15

    Purpose: The therapeutic regimen for cranial arteriovenous malformations often involves both stereotactic radiosurgery and endovascular embolization. Embolization agents may contain tantalum or other contrast agents to assist the neurointerventionalists, leading to concerns regarding the dosimetric effects of these agents. This study investigated dosimetric properties of n-butyl cyanoacrylate (n-BCA) plus lipiodol with and without tantalum powder. Methods: The embolization agents were provided cured from the manufacturer with and without added tantalum. Attenuation measurements were made for the samples and compared to the attenuation of a solid water substitute using a 6 MV photon beam. Effective linear attenuation coefficients (ELAC) were derived from attenuation measurements made using a portal imager and derived sample thickness maps projected in an identical geometry. Probable dosimetric errors for calculations in which the embolized regions are overridden with the properties of water were calculated using the ELAC values. Interface effects were investigated using a parallel plate ion chamber placed at set distances below fixed samples. Finally, Hounsfield units (HU) were measured using a stereotactic radiosurgery CT protocol, and more appropriate HU values were derived from the ELAC results and the CT scanner’s HU calibration curve. Results: The ELAC was 0.0516 ± 0.0063 cm{sup −1} and 0.0580 ± 0.0091 cm{sup −1} for n-BCA without and with tantalum, respectively, compared to 0.0487 ± 0.0009 cm{sup −1} for the water substitute. Dose calculations with the embolized region set to be water equivalent in the treatment planning system would result in errors of −0.29% and −0.93% per cm thickness of n-BCA without and with tantalum, respectively. Interface effects compared to water were small in magnitude and limited in distance for both embolization materials. CT values at 120 kVp were 2082 and 2358 HU for n-BCA without and with tantalum, respectively

  2. Structure and Vibrational Spectra of Tert-butyl N-(2- bromocyclohex-2-enyl)-N-(2-furylmethyl)carbamate%Tert-butyl(N-(2-bromocyclohex-2-enyl)-N-(2-furylmethyl)carbamate的结构和振动光谱

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The molecular structure, conformational stability, and vibrational frequencies of tert-butyl N-(2-bromocyclohex-2-enyl)-N-(2-furylmethyl)carbamate (TBBFC) were investigated by utilizing the Hartree-Fock (HF) and density functional theory (DFT) ab initio calculations with 6-31G* and 6-31G* * basis sets. The optimized bond length and angle values obtained by HF method showed the best agreement with the experimental values. Comparison of the observed and calculated fundamental vibrational frequencies indicated that B3LYP was superior to the scaled HF approach for molecular problems. Optimal uniform scaling factors calculated for the title compound are 0.899/0.904,0.958/0.961, and 0.988/0.989 for HF, B3LYP, and BLYP (6-31G */6-31G* *), respectively.

  3. Microbial degradation and fate in the environment of methyl tert-butyl ether and related fuel oxygenates.

    Science.gov (United States)

    Fayolle, F; Vandecasteele, J P; Monot, F

    2001-08-01

    Oxygenates, mainly methyl tert-butyl ether (MTBE), are commonly added to gasoline to enhance octane index and improve combustion efficiency. Other oxygenates used as gasoline additives are ethers such as ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and alcohols such as tert-butyl alcohol (TBA). As a result of its wide use, MTBE has been detected, mainly in the USA, in groundwater and surface waters, and is a cause of concern because of its possible health effects and other undesirable consequences. MTBE is a water-soluble and mobile compound that generates long pollution plumes in aquifers impacted by gasoline releases from leaking tanks. Field observations concur in estimating that, because of recalcitrance to biodegradation, natural attenuation is slow (half-life of at least 2 years). However, quite significant advances have been made in recent years concerning the microbiology of the degradation of MTBE and other oxygenated gasoline additives. The recalcitrance of these compounds results from the presence in their structure of an ether bond and of a tertiary carbon structure. For the most part, only aerobic microbial degradation systems have been reported so far. Consortia capable of mineralizing MTBE have been selected. Multiple instances of the cometabolism of MTBE with pure strains or with microflorae, growing on n-alkanes, isoalkanes, cyclohexane or ethers (diethyl ether, ETBE), have been described. MTBE was converted into TBA in all cases and was sometimes further degraded, but it was not used as a carbon source by the pure strains. However, mineralization of MTBE and TBA by several pure bacterial strains using these compounds as sole carbon and energy source has recently been reported. The pathways of metabolism of MTBE involve the initial attack by a monooxygenase. In several cases, the enzyme was characterized as a cytochrome P-450. After oxygenation, the release of a C -unit as formaldehyde or formate leads to the production of TBA

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-01-02

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

  5. Solubilities of carbon dioxide and oxygen in the ionic liquids methyl trioctyl ammonium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)imide, and 1-butyl-3-methyl imidazolium methyl sulfate.

    Science.gov (United States)

    Bahadur, Indra; Osman, Khalid; Coquelet, Christophe; Naidoo, Paramespri; Ramjugernath, Deresh

    2015-01-29

    Ionic liquids (ILs) are being considered as solvents for gas absorption processes as they have the potential, in general, for improved efficiency of gas separations, as well as lower capital and operating costs compared to current commercial processes. In this study the solvent properties of ILs are investigated for use in the absorption of carbon dioxide (CO2) and oxygen (O2). The absorption of these gases in ILs was measured in the temperature range 303.15-333.15 K and at pressures up to 1.5 MPa by gravimetric analysis. The ILs used were methyl trioctyl ammonium bis (trifluoromethylsulfonyl) imide ([MOA][Tf2N]), 1-butyl-3-methyl imidazolium bis (trifluoromethylsulfonyl) imide ([BMIM][Tf2N]), and 1-butyl-3-methyl imidazolium methyl sulfate ([BMIM][MeSO4]). The measurement technique employed in this study is fast and accurate, and requires small quantities of solvent. The results indicated that absorption of both gases increased with a decrease in operating temperature and an increase in pressure. [MOA][Tf2N] had the highest CO2 and O2 solubility. [BMIM][Tf2N] was determined to have the highest selectivity for CO2 absorption. [BMIM][MeSO4] achieved the lowest CO2 absorption with a moderate O2 absorption, revealing this IL to be the least desirable for CO2 and O2 absorption. Calculation of Henry's law constants for all systems confirmed the deductions made from absorption data analysis. Calculation of enthalpy and entropy of absorption for each system revealed CO2 absorption in [MOA][Tf2N] to be the least sensitive to temperature increases. The absorption data was modeled using the generic Redlich-Kwong cubic equation of state (RK-EOS) coupled with a group contribution method.

  6. Separation of Ephedrines Using 1-Butyl-3-methylimidazolium-tetrafluoroborate Ionic Liquids as Eluent in High-performance Liquid Chromatography (HPLC)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A simple, effective HPLC method for separation of ephedrines was achieved by using1-butyl-3-methylimidazolium-tetrafluoroborate ionic liquid solution (0.1% v/v) as eluent at pH 3.0.The involved mechanism may be due to that the imidazolium cations can effectively shield thesilanol groups of alkylsilica surface, thereby decreasing band tailing and increasing the separationefficiency.

  7. 1-Butyl-3-methylimidazolium Hydrogen Sulfate [bmim]HSO4: An Efficient Reusable Acidic Ionic Liquid for the Formylation of Alcohols

    Institute of Scientific and Technical Information of China (English)

    NIKNAM Khodabakhsh; ZOLFIGOL Mohammad Ali; SABERI Dariush; KHONBAZI Mahdi

    2009-01-01

    1-Butyl-3-methylimidazolium hydrogen sulfate [bmim]HSO4 as an acidic ionic liquid was prepared and used as a catalyst for the formylation of alcohols with ethyl formate at room temperature with good to excellent yields.A good selectivity was observed for the formylation of primary alcohols in the presence of tertiary alcohols.

  8. Ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br: a green and neutral reaction media for the efficient, catalyst-free synthesis of quinoxaline derivatives

    Directory of Open Access Journals (Sweden)

    MAASOOMEH KHEDRI

    2010-10-01

    Full Text Available Quinoxaline derivatives were produced in excellent yields and short reaction times via the condensation of 1,2-diamines with 1,2-diketones in the neutral ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br under catalyst-free and microwave irradiation conditions.

  9. Intra-arterial tert-Butyl-hydroperoxide infusion induces an exacerbated sensory response in the rat hind limb and is associated with an impaired tissue oxygen uptake.

    NARCIS (Netherlands)

    Tan, E.C.T.H.; Goor, H. van; Bahrami, S.; Kozlov, A.V.; Leixnering, M.; Redl, H.; Goris, R.J.A.

    2011-01-01

    The objective of this study was to investigate oxidative stress and oxygen extraction mechanisms in an animal model of continuous intra-arterial infusion of a free radical donor and in an in vitro model using isolated mitochondria. tert-Butyl-hydroperoxide (tert-BuOOH, 25 mM) was infused for 24 h in

  10. Isomerization of 4-Amino-6-tert-butyl-3-methylthio-1, 2,4-triazin-5 (4H)-one with Base

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Isomerizaton of 4-amino-6-tert-butyl-3-methylthio-1, 2, 4-triazin-5 (4H)-one in the presence of base is described. Mechanism of this rearrangement reaction involving four-member ring intermediate formation has been proposed.

  11. X-Ray Structure of 8-Quinolinolato Lanthanide Complex:(8-Quinolinolato) bis (2,6-di-tert-butyl-4-methylphenoxo) samarium

    Institute of Scientific and Technical Information of China (English)

    YUAN,Fu-Gen(袁福根); LIU,Qing-Sheng(刘青生); WENG,Lin-Hong(翁林红)

    2002-01-01

    The heteroleptic (8-quinolinolato)bis(2,6-di-tert-butyl-4-methylphenoxo) samarium complex was synthesized and characterized by elemental analysis, IR spectrun and X-ray diffraction analysis. The complex is a five-coordinate dimer. Each 8-quinolinolato oxygen atom links two samarium atoms as a bridge and the Sm-N bond is a typical donor bond.

  12. Systemic uptake of diethyl phthalate, dibutyl phthalate, and butyl paraben following whole-body topical application and reproductive and thyroid hormone levels in humans

    DEFF Research Database (Denmark)

    Janjua, Nadeem Rezaq; Mortensen, Gerda Krogh; Andersson, Anna-Maria

    2007-01-01

    In vitro and animal studies have reported endocrine-disrupting activity of chemicals used commonly as additives in cosmetics and skin care products. We investigated whether diethyl phthalate (DEP), dibutyl phthalate (DBP), and butyl paraben (BP) were systemically absorbed and influenced endogenous...

  13. 40 CFR 721.1730 - Poly(oxy-1,2-ethanediyl), α-butyl-ω-hydroxy, ester with boric acid (H3BO3).

    Science.gov (United States)

    2010-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1730 Section 721.1730 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-butyl-ω-hydroxy, ester with...

  14. URINARY AND AMNIOTIC FLUID LEVELS OF PHTHALATE MONOESTERS IN RATS AFTER THE ORAL ADMINISTRATION OF DI(2-ETHYLHEXYL) PHTHALATE AND DI-N-BUTYL PHTHALATE

    Science.gov (United States)

    Two studies were designed to examine amniotic fluid and maternal urine concentrations of the di(2-ethylhexyl) phthalate (DEHP) metabolite mono(2-ethylhexyl) phthalate (MEHP) and the di-n-butyl phthalate (DBP) metabolite monobutyl phthalate (MBP) after administration of DEHP and D...

  15. Second harmonic generation at the interface of copper tetra-tert-butyl phthalocyanine Langmuir-Blodgett film/metal

    Institute of Scientific and Technical Information of China (English)

    程晓曼; 姚素薇; 李成全; 间中孝彰; 岩本光正

    2003-01-01

    Optical second harmonic generation (SHG) from the copper tetra-tert-butyl phthalocyanine (CuttbPc) Langmuir-Blodgett (LB) film deposited on a metal-coated glass slide substrate has been investigated. It is considered that the symmetry of the CuttbPc molecule may be broken by the space charge-induced electric field (SCIEF) due to the exchanged charges at the CuttbPc LB film/metal interface. A four-layer model is used to explain the nonlinear optical process in the CuttbPc LB film. The thickness dependence, polarized and incident angle dependence of SHG signal from CuttbPc LB films are calculated. The results of calculation show a good agreement with the experimental data. It is shown that electrostatic phenomena at the interface is correlated closely with SHG signal, and the SHG measurement is also a helpful tool for the detection of the space charge field at the interface.

  16. Production and market analysis of butyl rubber%丁基橡胶生产及市场分析

    Institute of Scientific and Technical Information of China (English)

    刘隽姝; 王东巍; 吴玉峰; 王启弘

    2012-01-01

    Butyl rubber(IIR) is an unreplacbale rubber of the tyre with or without inner tube due to its excellent airtightness, watertightness, weathering resistance and chemical anticorrosivity. This paper inroduces production actuality of IIR, summarizes production capacity, import/export and appearance consumption of IRR,and analyzes and predicts market trend. Furthermore, this paper gives some advices on domestic IIR industry development.%介绍了国内外丁基橡胶(IIR)的生产现状,总结了IIR的产能、进出口量和表观消费量,并对国内IIR的市场发展趋势进行了分析及预测.此外,还对国内IIR行业的发展提出了几点建议.

  17. When does the fluazifop-P-butyl degradate, TFMP, leach through an agricultural loamy soil to groundwater?

    DEFF Research Database (Denmark)

    Vendelboe, Anders Lindblad; Norgaard, Trine; Olsen, Preben;

    2016-01-01

    that pesticide degradates like TFMP, often being more soluble than the pesticide, have a relatively high leaching potential especially associated with heavy precipitation events shortly after the application. Hence, such pesticide degradates should like in Denmark be considered “relevant” meaning that the EU...... value for drinking water applies to them, having its leaching potential regulatory assessed based on high quality estimations of their persistence, and be exposed to an assessment of the risk to consumers of drinking contaminated groundwater.......In intensely cultivated regions, it is crucial to have knowledge of the leaching potential related to pesticides in agricultural production. This is especially true in countries, like Denmark, that base its drinking water supply on untreated groundwater. Since fluazifop-P-butyl (FPB) is applied...

  18. A comparative study of biodiesel production using methanol, ethanol, and tert-butyl methyl ether (MTBE) under supercritical conditions.

    Science.gov (United States)

    Farobie, Obie; Matsumura, Yukihiko

    2015-09-01

    In this study, biodiesel production under supercritical conditions among methanol, ethanol, and tert-butyl methyl ether (MTBE) was compared in order to elucidate the differences in their reaction behavior. A continuous reactor was employed, and experiments were conducted at various reaction temperatures (270-400 °C) and reaction times (3-30 min) and at a fixed pressure of 20 MPa and an oil-to-reactant molar ratio of 1:40. The results showed that under the same reaction conditions, the supercritical methanol method provided the highest yield of biodiesel. At 350 °C and 20 MPa, canola oil was completely converted to biodiesel after 10, 30, and 30 min in the case of - supercritical methanol, ethanol, and MTBE, respectively. The reaction kinetics of biodiesel production was also compared for supercritical methanol, ethanol, and MTBE.

  19. Energy analysis for the production of biodiesel in a spiral reactor using supercritical tert-butyl methyl ether (MTBE).

    Science.gov (United States)

    Farobie, Obie; Matsumura, Yukihiko

    2015-11-01

    In this study, energy analysis was conducted for the production of biodiesel in a spiral reactor using supercritical tert-butyl methyl ether (MTBE). This study aims to determine the net energy ratio (NER) and energy efficiency for the production of biodiesel using supercritical MTBE and to verify the effectiveness of the spiral reactor in terms of heat recovery efficiency. The analysis results revealed that the NER for this process was 0.92. Meanwhile, the energy efficiency was 0.98, indicating that the production of biodiesel in a spiral reactor using supercritical MTBE is an energy-efficient process. By comparing the energy supply required for biodiesel production between spiral and conventional reactors, the spiral reactor was more efficient than the conventional reactor.

  20. EFFECT OF 2—HYDROXYETHYL METHACRYLATE ON SEMIBATCH EMULSIFIER—FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE AND BUTYL ACRYLATE

    Institute of Scientific and Technical Information of China (English)

    GUOTianying; SONGMoudao; 等

    1999-01-01

    The semibatch emulsifier-free emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate(BA) in the presence of 2-hydroxyethyl methacrylate(HEMA) initiated by K2S2O8(PSP) was studied.The latex particles can maintain an appreciable stability during the emulsifier-free emulsion copolymerization of MMA and BA in the presence of HEMA.The average particle diameter increase with an increase of total solids content,HEMA content,PSP content,ionic strength of the system and monomer feed rate,and decrease with the monomer feed ration from 3/1 (MMA/BA:molar ration).to 1/3.The stability of this reaction system is improved by adding HEMA as nonionic comonomer,High solids content (50%) latex with monodisperse particle can be obtained using this process.

  1. Polymerization behaviour of butyl bis(hydroxymethyl)phosphine oxide: Phosphorus containing polyethers for Li-ion conductivity

    Indian Academy of Sciences (India)

    Heeralal Vignesh Babu; Billakanti Srinivas; Khevath Praveen Kumar Naik; Krishnamurthi Muralidharan

    2015-04-01

    Synthesis of phosphorus containing polyethers and their lithium-ion conductivities for the potential use as solid polymer electrolyte (SPE) in high-energy density lithium-ion batteries have been described. Co-polymerization of butyl bis(hydroxymethyl)phosphine oxide with three different dibromo monomers were carried out to produce three novel phosphorous containing polyethers (P1–P3). These polymers were obtained via nucleophilic substitution reactions and were characterized by 1H, 31P NMR spectral data and gel permeation chromatography. SPEs were prepared using polyethers (P1 and P2) with various amounts of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The lithium-ion conductivity of SPE2 containing 40 wt% of LiTFSI was 2.1 × 10−5 S cm−1 at room temperature and 3.7 × 10−4 S cm−1 at 80°C.

  2. (2E-4-tert-Butyl-2-(4-methoxybenzylidene-3,4-dihydronaphthalen-1(2H-one

    Directory of Open Access Journals (Sweden)

    Mohamed Akhazzane

    2011-07-01

    Full Text Available In the title compound C22H24O2, the exocyclic C=C double bond is in an E configuration and the tert-butyl group is in an axial position on the cyclohexanone ring. The cyclohexanone ring in the dihydronaphthalene fused-ring system adopts a half-chair conformation in both independent two molecules in the asymetric unit. The benzene ring system is oriented angles of 43.97 (12 and 39.24 (12° with respect to the naphthyl ring system in the two independent molecules. In the crystal, molecules are linked via C—H...O hydrogen bonds and C—H...π interactions.

  3. Stereochemical dependence of 3JCH coupling constants in 2-substituted 4-t-butyl-cyclohexanone and their alcohol derivatives.

    Science.gov (United States)

    Favaro, Denize C; Ducati, Lucas C; dos Santos, Francisco P; Contreras, Rubén H; Tormena, Cláudio F

    2011-12-22

    Theoretical and experimental studies on (3)J(C2H6eq) NMR spin-spin coupling constants in both the 2-X-4-t-butyl-cyclohexanone (X = H, CH(3), F, Cl, and Br) and in their alcohol derivatives series are reported. Results thus found are rationalized in terms of the transmission of the Fermi contact contribution to such couplings. To this end, dependencies of (3)J(C2H6eq) couplings versus the C(2)-C(1)-C(6) angle are compared in both series for equatorial and axial X orientations. The main trend is described in terms of the rear lobes interaction. Besides, for X = halogen atom in equatorial orientation a rather strong interaction between oxygen and halogen lone pairs is observed, and its influence on (3)J(C2H6eq) couplings is discussed and rationalized in terms of different Fermi contact transmission pathways.

  4. Conformational analysis of cyclic sulphites. 2-Oxo 1,3,2-dioxathiane-4-spiro-4- tert-butyl-cyclohexanes

    Science.gov (United States)

    Cazaux, Louis; Koudsi, Yahia; Maroni, Pierre

    Three series of 4-spirosulphites, a new class of cyclic sulphites, were synthesized and five couples of diastereoisomers isolated. Their structural analysis, using 1H NMR coupling constants and SO stretching vibration as conformational probes, shows a large variety of ananchomeric chair forms and multicomponent equilibria for the cyclic sulphite moiety, the cyclohexane part of the molecule remaining in the chair form. Related to the occurrence of severe interactions involving the 5-methyl or 6- tert. butyl substituent, several twist forms were encountered, with 2,5-axis and isoclinal SO or 1,4-axis and axial or equatorial SO as a consequence of the weak free energy difference between chair and twist conformations in the cyclic sulphite series.

  5. Solubilities of benzene, toluene and diphenyl in the t-butyl alcohol + water mixtures and hydrophobic interaction

    Institute of Scientific and Technical Information of China (English)

    邹立壮; 杨冠英; 韩布兴; 刘瑞麟; 阎海科

    1999-01-01

    The solubilitices of benzene, toluene and diphenyl in mixed solvents of t-butyl alcohol (TBA) and water at 283.15, 288.15, 293.15 and 298.15 K have been determined by spectrophotometry. The mole fraction of TBA [x (TBA)] in the mixed solvent are 0.000, 0.010, 0.020, 0.030, 0.040, 0.045, 0.050, 0.060, 0.080 and 0.100, respectively. The standard Gibbs energies of solution of benzene, toluene and diphenyl in the mixed solvent have also been calculated based on the solubility data. The hydrophobic interactions (HI) for the pairs of benzene-benzene, methane-benzene and methane-methane in the mixed solvent were calculated and discussed.

  6. An ellagitannin, n-butyl gallate, two aryltetralin lignans, and an unprecedented diterpene ester from Pelargonium reniforme.

    Science.gov (United States)

    Latté, Klaus Peter; Kaloga, Maki; Schäfer, Andreas; Kolodziej, Herbert

    2008-02-01

    The structural diversity of the metabolic pool of Pelargonium reniforme was extended by the characterization of the 1C4-glucose based ellagitannin pelargoniin E, gallic acid n-butyl ester, (-)-4,4',9'-trihydroxy-3',5'-dimethoxy-2,7'-cyclolignan 9-O-beta-glucopyranoside and reniformin, a diterpene ester comprised of a diterpene acid with an uncommon -(CH2)(2)- bridging element linked to 2-(4-hydroxyphenyl)ethansulfonic acid. These metabolites were associated with the known (alpha,beta)-3,4-di-O-galloyl-glucopyranoside, 4,6-dihydroxy-2beta-glucopyranosyloxyacetophenone, 1-O-galloylglycerol, 6'-O-galloylsalidroside and (+)-isolariciresinol-9'-O-beta-glucopyranoside. All structures were established on the basis of spectroscopic methods.

  7. PREAPARATION OF CATIONIC LATEXES OF POLY(STYRENE-CO-BUTYL ACRYLATE) AND THEIR PROPERTIES EVOLUTION IN LATEX DILUTION

    Institute of Scientific and Technical Information of China (English)

    Dong Zou; Xiu-fen Li; Xiao-li Zhu; Xiang-zheng Kong

    2012-01-01

    Cationic latexes were prepared through emulsion copolymerization of styrene (St) and butyl acrylate (BA) with a cationic surfactant,cetyl trimethyl ammonium bromide (CTAB).Latex properties,including particle size,size distribution,ζ potential,surface tension and monomer conversion,were determined for latexes prepared with different CTAB amounts.Evolution of these properties during emulsion polymerization was followed in order to understand the mechanism of the particles formation.Results showed that both particle size and ζpotential were function of polymerization time and latex solids.Parallel emulsion polymerizations with cationic,anionic charged initiator and charge-free initiators were also carried out,the latex properties were determined at different polymerization time.All these results were attentively interpreted based on the mechanisms of emulsion polymerization,surfactant adsorption and latex particle stabilization.

  8. Kinetics of adsorption of di-n-butyl phthalate (DBP) by four different granule-activated carbons

    Institute of Scientific and Technical Information of China (English)

    Po keung TSANG; Zhanqiang FANG; Hui LIU; Xiaolei CHEN

    2008-01-01

    The kinetics of the adsorption of an endocrine disruptor,di,n,butyl phthalate (DBP),by four different granulated,activated carbons (GACs) is presented in this paper. Results showed that adsorption of DBP by the four GACs followed first,order kinetics and the adsorption constant of the four GAC was found to follow the order:nut shell>coconut shell>Coaly carbon 1.0>Coaly carbon 1.5. Batch adsorption studies were also conducted to investigate the effect of pH on the adsorption process. The optimum pH for the removal of DBP from aqueous solutions under the experimental conditions used in this work was found to be 5.0. The characterization of the carbon surfaces was conducted by using scanning electron microscopy (SEM). Furthermore,results from infrared spectroscopic (IR) studies showed that physical adsorption plays an important role in the adsorption of DBP by the four selected GACs.

  9. CO2 capture from binary mixture via forming hydrate with the help of tetra-n-butyl ammonium bromide

    Institute of Scientific and Technical Information of China (English)

    Shifeng Li; Shuanshi Fan; Jingqu Wang; Xuemei Lang; Deqing Liang

    2009-01-01

    Hydrate formation rate and separation effect on the capture of CO2 from binary mixture v/a forming hydrate with 5 wt% tetra-n-butyl ammonium bromide (TBAB) solution were studied.The results showed that the induction time was 5 min,and the hydrate formation process pressure of 7.30 MPa.The CO2 recovery was about 45% in the feed pressure range from 4.30 to 7.30 MPa.Under the feed pressure of 4.30 MPa,the maximum separation factor and CO2 concentration in hydrate phase were 7.3 and 38.2 tool%,respectively.The results demonstrated that TBAB accelerated hydrate formation and enriched CO2 in hydrate phase under the gentle condition.

  10. Effect of Oxygen on Surface Properties and Drug Release Behavior of Plasma Polymer of n-Butyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    Yuan YUAN; Chang Sheng LIU; Yuan ZHANG; Min YIN; Jie XU

    2005-01-01

    The effects of oxygen on the chemical structure, morphology, hydrophilicity and drug release behavior of radio-frequency plasma poly n- butyl methacrylate (PPBMA) thin film were carried out for the first time. ATR-FTIR and XPS showed that oxygen had little influence on the chemical structure and composition of PPBMAs, which did not agree with the thought that the presence of oxygen gas would increase the oxidized carbon functionalities in the plasma polymer.SEM and static contact angle measurement indicated that in case of deposition with oxygen, the smoothness and hydrophilicity of PPBMA were dramatically improved. The drug release behavior showed that drug release from the PPBMA coating without oxygen was biphasic patterns,while from PPBMA coating with oxygen was Higuchi release. These results were helpful for the design and tailoring of the PPBMA polymer film and other of plasma polymers film, but could provide a new idea for the drug release controlled form.

  11. UV absorption spectra, kinetics and mechanism for alkyl and alkyl peroxy radicals originating from t-butyl alcohol

    DEFF Research Database (Denmark)

    Langer, S.; Ljungström, E.; Sehested, J.

    1994-01-01

    Alkyl and alkyl peroxy radicals from 1-butyl alcohol (TBA), HOC (CH3)2CH2. and HOC(CH3)2CH2O2. have been studied in the ps phase at 298 K. Two techniques were used: pulse radiolysis UV absorption to measure the spectra and kinetics, and long path-length Fourier transform infrared spectroscopy (FTIR......) to identify and quantify the reaction products. Absorption cross sections were quantified over the wavelength range 220-320 nm. At 240 nm, sigma(HOC(CH3)2CH2) = (2.4 +/- 0.3) x 10(-18) and sigma(HOC(CH3)2CH2O2) = (3.4 +/- 0.5) X 10(-18) cm2 molecule-1 have been obtained. Observed rate constants for the self...

  12. Polymer electrolyte based on crosslinked poly(glycidyl methacrylate) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Beatrice Wong Chui; Hanifah, Sharina Abu; Ahmad, Azizan; Hassan, Nur Hasyareeda [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43000 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    Polymer electrolytes based on crosslinked poly(glycidyl methacrylate) as polymer host and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BmimTFSI) as incorporated salt were prepared by in-situ photopolymerization technique. The complexes with different mass ratio of glycidyl methacrylate (GMA) monomer to BmimTFSI were investigated. The ionic conductivity of the polymer electrolyte was increased and reach the highest value of 7.50 × 10{sup −4} S cm{sup −1} at the ratio of 3:7 (GMA: BmimTFSI). The interaction between the polymer host and ionic liquid was proved by Attenuated Total Reflectance-Fourier Transformation Infra-Red Spectroscopy (ATR-FTIR). Meanwhile, the X-ray diffraction analysis shows the amorphousity of the polymer electrolyte film increase with the ionic liquid ratio.

  13. Chitosan-graft-poly(n-butyl acrylate) copolymer: Synthesis and characterization of a natural/synthetic hybrid material.

    Science.gov (United States)

    Anbinder, Pablo; Macchi, Carlos; Amalvy, Javier; Somoza, Alberto

    2016-07-10

    Two chitosan polymers with different deacetylation degree and molecular weight were subjected to grafting reactions with the aim to enhance the properties of these bio-based materials. Specifically, n-butyl acrylate in different proportions was grafted onto two different deacetylation degree (DD%) chitosan using radical initiation in a surfactant free emulsion system. Infrared spectroscopy was used to confirm grafting and products grafting percentage and efficiency were evaluated against acrylate/chitosan ratio and DD%. Thermal and structural properties and the behavior against water of the raw and grafted biopolymers were studied using several experimental techniques: differential scanning calorimetry, transmission electron microscopy, dynamic light scattering, water swelling, contact angle and positron annihilation lifetime spectroscopy. The influence of the grafting process on the morphological and physicochemical properties of the prepared natural/synthetic hybrid materials is discussed.

  14. Comparison and Characterisation of Regenerated Chitosan from 1-Butyl-3-methylimidazolium Chloride and Chitosan from Crab Shells

    Directory of Open Access Journals (Sweden)

    Saniyat Islam

    2015-01-01

    Full Text Available Chitosan is a biopolymer derived from chitin which is naturally occurring in the exoskeleton of crustaceans. This paper reports dissolution and regeneration of chitosan by directly dissolving in an ionic liquid solvent, 1-butyl-3-methylimidazolium chloride (BMIMCl. This will provide an ideal platform to solubilise these kinds of polymers to achieve the dissolution. The current study dissolved chitosan from crab shell utilising BMIMCl as a solvent and characterised the resultant regenerated polymer. The regenerated chitosan showed increased hydrogen bonding when characterised by Fourier transform infrared (FTIR spectral analysis. In addition, the study also compared the characteristics of regenerated and generic chitosan. The regenerated chitosan was also evaluated for antimicrobial properties and showed to possess antibacterial features similar to the commercial grade. This method can be utilised in future for blending of polymers with chitosan in a dissolved phase.

  15. Comparison and Characterisation of Regenerated Chitosan from 1-Butyl-3-methylimidazolium Chloride and Chitosan from Crab Shells.

    Science.gov (United States)

    Islam, Saniyat; Arnold, Lyndon; Padhye, Rajiv

    2015-01-01

    Chitosan is a biopolymer derived from chitin which is naturally occurring in the exoskeleton of crustaceans. This paper reports dissolution and regeneration of chitosan by directly dissolving in an ionic liquid solvent, 1-butyl-3-methylimidazolium chloride (BMIMCl). This will provide an ideal platform to solubilise these kinds of polymers to achieve the dissolution. The current study dissolved chitosan from crab shell utilising BMIMCl as a solvent and characterised the resultant regenerated polymer. The regenerated chitosan showed increased hydrogen bonding when characterised by Fourier transform infrared (FTIR) spectral analysis. In addition, the study also compared the characteristics of regenerated and generic chitosan. The regenerated chitosan was also evaluated for antimicrobial properties and showed to possess antibacterial features similar to the commercial grade. This method can be utilised in future for blending of polymers with chitosan in a dissolved phase.

  16. Understanding the large solubility of lidocaine in 1-n-butyl-3-methylimidazolium based ionic liquids using molecular simulation

    Science.gov (United States)

    Ley, Ryan T.; Paluch, Andrew S.

    2016-02-01

    Room temperature ionic liquids have been proposed as replacement solvents in a wide range of industrial separation processes. Here, we focus on the use of ionic liquids as solvents for the pharmaceutical compound lidocaine. We show that the solubility of lidocaine in seven common 1-n-butyl-3-methylimidazolium based ionic liquids is greatly enhanced relative to water. The predicted solubility is greatest in [BMIM]+[CH3CO2]-, which we find results from favorable hydrogen bonding between the lidocaine amine hydrogen and the [CH3CO2]- oxygen, favorable electrostatic interactions between the lidocaine amide oxygen with the [BMIM]+ aromatic ring hydrogens, while lidocaine does not interfere with the association of [BMIM]+ with [CH3CO2]-. Additionally, by removing functional groups from the lidocaine scaffold while maintaining the important amide group, we found that as the van der Waals volume increases, solubility in [BMIM]+[CH3CO2]- relative to water increases.

  17. Structure-Dependent 4-Tert-Butyl Pyridine-Induced Band Bending at TiO2 Surfaces

    Directory of Open Access Journals (Sweden)

    Mats Göthelid

    2011-01-01

    Full Text Available The role of 4-tert butyl pyridine (4TBP adsorption on TiO2 surface band bending has been studied using photoelectron spectroscopy. Surface oxygen vacancies pin the Fermi level near the conduction band edge on rutile (110. 4TBP preferentially adsorbs in those vacancies and shift the Fermi level to lower binding energy in the band gap. This is done by transferring vacancy excess charge into the empty π∗ orbital in the pyridine ring. The anatase (100 surface contains much less oxygen vacancies although the surface is much rougher than the rutile (110. 4TBP adsorption does not have any significant effect on the surface band bending. Thus the positive role associated with 4TBP addition to solar cell electrolytes is suggested to protection against adsorption of other electrolyte components such as Li and I.

  18. Vibrational Spectroscopic Studies and Computational Study of 1,2-Diphenyl-4-n-Butyl-3,5-Pyrazolidinedione

    Directory of Open Access Journals (Sweden)

    C. Yohannan Panicker

    2011-01-01

    Full Text Available FT-IR and FT-Raman spectra of 1,2-diphenyl-4-n-Butyl-3,5-pyrazolidinedione (Phenylbutazone were recorded and analyzed. The vibrational wavenumbers were computed using HF/6-31G(d and B3LYP/6-31G(d basis sets and compared with experimental data. The first hyperpolarizability, infrared intensities and Raman activities are also reported. The geometrical parameters of the title compound obtained from theoretical calculations are in agreement with that of reported similar derivatives. The first hyperpolarizability is comparable with reported values of similar derivatives and is an attractive molecule for future applications in non-linear optics. The variation in C-N bond lengths suggests an extended π-electron delocalization over the pyrazolidinedione moiety which is responsible for the nonlinearity of the molecule.

  19. HALONICKEL 2,4-DI-t-BUTYL-6-(QUINOLIN-8-YLIMINOMETHYL)PHENOLATES:SYNTHESIS, CHARACTERIZATION AND ETHYLENE REACTIVITY

    Institute of Scientific and Technical Information of China (English)

    Qi-song Shi; Xiang Hao; Carl Redshaw; Wen-hua Sun

    2013-01-01

    A series of nickel halides bearing 2,4-di-t-butyl-6-(quinolin-8-yliminomethyl) phenolate ligands was synthesized and characterized by IR spectroscopy and elemental analysis.Molecular structures of C1 (R =H,X =Br) and C2 (R =H,X =Cl) were further confirmed by single-crystal X-ray crystallographic studies,and revealed a distorted square planar geometry at nickel.Upon activation with diethylaluminum chloride (Et2AlCl),all nickel pre-catalysts displayed good catalytic activity [up to 9.3 × 105 g mol-1(Ni) h-1] for ethylene oligomerization with major dimerization.In the presence of methylaluminoxane (MAO),the nickel complex C1 was capable of ethylene polymerization under 3 MPa,and produced polyethylene products with narrow polydispersity (1.16-1.73) and molecular weights in the range of 2.6-4.95 kg/mol.

  20. 7-[(3,5-Di-tert-butyl-2-hydroxybenzylideneamino]-4-methyl-2H-chromen-2-one

    Directory of Open Access Journals (Sweden)

    Orhan Büyükgüngör

    2010-10-01

    Full Text Available The title compound, C25H29NO3, is a Schiff base derivative of coumarin 120. There are two structurally similar but crystallographically independent molecules in the asymmetric unit. Both molecules exist in E configurations with respect to the C=N double bonds. The dihedral angles between the coumarin and 3,5-di-tert-butyl-2-hydroxybenzylidene ring planes are 4.62 (7 and 14.62 (7° for the two molecules. Intramolecular O—H...N hydrogen bonding involving the O—H groups and the azomethine N atoms generate S(6 rings. In the crystal structure, independent molecules are linked by C—H...π interactions, with groups of four molecules stacked along the c axis.

  1. A subchronic (180-day) oral toxicity study of ethyl tertiary-butyl ether, a bioethanol, in rats.

    Science.gov (United States)

    Miyata, Katsumi; Koga, Takayuki; Aso, Sunao; Hoshuyama, Satsuki; Ajimi, Syozo; Furukawa, Kotaro

    2014-07-01

    A subchronic (180-day) toxicity study was conducted to evaluate the effects of ethyl tertiary-butyl ether (ETBE), a biomass fuel, in male and female rats. ETBE was administered at dose levels of 0, 5, 25, 100 and 400 mg/kg/body weight (b.w.)/day by gavage. No treatment-related adverse effects were observed at 5, 25 or 100 mg/kg. Centrilobular hypertrophy of hepatocytes was observed in males and females and their relative liver weights were increased, suggesting enhanced metabolic activity. From these results, we concluded that the no observed adverse effect level of ETBE was 100 mg/kg b.w./day under the conditions tested.

  2. ETBE (ethyl tert butyl ether) and TAME (tert amyl methyl ether) affect microbial community structure and function in soils.

    Science.gov (United States)

    Bartling, Johanna; Esperschütz, Jürgen; Wilke, Berndt-Michael; Schloter, Michael

    2011-03-15

    Ethyl tert butyl ether (ETBE) and tert amyl methyl ether (TAME) are oxygenates used in gasoline in order to reduce emissions from vehicles. The present study investigated their impact on a soil microflora that never was exposed to any contamination before. Therefore, soil was artificially contaminated and incubated over 6 weeks. Substrate induced respiration (SIR) measurements and phospholipid fatty acid (PLFA) analysis indicated shifts in both, microbial function and structure during incubation. The results showed an activation of microbial respiration in the presence of ETBE and TAME, suggesting biodegradation by the microflora. Furthermore, PLFA concentrations decreased in the presence of ETBE and TAME and Gram-positive bacteria became more dominant in the microbial community.

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

    Directory of Open Access Journals (Sweden)

    Gholam H.S. Bonjar

    2005-01-01

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

  4. Simultaneous Determination of Tert-Butyl Hydroquinone and Butylated Hydroxyanisole in Foods by High Performance Liquid Chromatography with Fluorimetric Detection%反相高效液相色谱-荧光法同时测定食品中叔丁基对苯二酚和叔丁基羟基茴香醚的含量

    Institute of Scientific and Technical Information of China (English)

    徐琴; 汤志旭; 林洪; 江志刚; 牟志春

    2008-01-01

    油溶性抗氧化剂叔丁基对苯二酚(tert-butyl hydroquinone,TBHQ)、叔丁基羟基茴香醚(butylated hydroxyanisole,BHA)和2,6-二叔丁基对甲酚(butylated hydroxytoluene,BHT)是目前最常用的化学合成抗氧化剂,能够有效阻止或延迟油脂氧化变质。然而TBHQ、BHA和BHT均具有一定的急性毒性和慢性致癌作用,过量添加会损害人体健康,

  5. Solid state {sup 1}H spin-lattice relaxation and isolated-molecule and cluster electronic structure calculations in organic molecular solids: The relationship between structure and methyl group and t-butyl group rotation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianlong, E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, 4 North Jianshe Rd., 2nd Section, Chengdu 610054 (China); Mallory, Frank B. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Mallory, Clelia W. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323 (United States); Odhner, Hosanna R.; Beckmann, Peter A., E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Department of Physics, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States)

    2014-05-21

    We report ab initio density functional theory electronic structure calculations of rotational barriers for t-butyl groups and their constituent methyl groups both in the isolated molecules and in central molecules in clusters built from the X-ray structure in four t-butyl aromatic compounds. The X-ray structures have been reported previously. We also report and interpret the temperature dependence of the solid state {sup 1}H nuclear magnetic resonance spin-lattice relaxation rate at 8.50, 22.5, and 53.0 MHz in one of the four compounds. Such experiments for the other three have been reported previously. We compare the computed barriers for methyl group and t-butyl group rotation in a central target molecule in the cluster with the activation energies determined from fitting the {sup 1}H NMR spin-lattice relaxation data. We formulate a dynamical model for the superposition of t-butyl group rotation and the rotation of the t-butyl group's constituent methyl groups. The four compounds are 2,7-di-t-butylpyrene, 1,4-di-t-butylbenzene, 2,6-di-t-butylnaphthalene, and 3-t-butylchrysene. We comment on the unusual ground state orientation of the t-butyl groups in the crystal of the pyrene and we comment on the unusually high rotational barrier of these t-butyl groups.

  6. Photosynthetic characteristics of cassava cultivars treated with fluazifop-p-butyl and fomesafen = Características fotossintéticas de cultivares de mandioca tratadas com fluazifop-p-butyl e fomesafen

    Directory of Open Access Journals (Sweden)

    Hellen Martins da Silveira

    2012-12-01

    Full Text Available The spending on weed control is an important component of production cost of cassava. It may be due to a limited availability of registered herbicides for use on this culture. To select new selective herbicides for cultures, it may be used the evaluation of plant photosynthetic characteristics after application. Thus, with this work, it was aimed to evaluate the effects of fluazifop-p-butyl and fomesafen herbicides, applied separately and in mixture, on the photosynthetic variables of five cassava cultivars (Cacau-UFV, Platina, Coqueiro, Coimbra and IAC-12. The treatments were applied 30 days after planting, when the cassava plants had approximately 30 centimeters of height. 30 days after application of treatments, it was evaluated substomatic CO2 concentration, photosynthetic rate and CO2 consumption by culture. The mixture of the herbicides fluazifopp - butyl + fomesafen caused increases in the quantity of CO2 consumed, CO2 concentration in the substomatal chambers and photosynthetic rate of the cultivars evaluated. However, the application of herbicides separately did not alter the characteristics evaluated with potential for use in post-emergence of cassava.= Um dos mais importantes componentes do custo de produção da mandioca refere-se aos gastos com o controle de plantas daninhas. Isto pode ser atribuído a pouca disponibilidade de herbicidas registrados para uso nessa cultura. Uma das maneiras para selecionar novos agrotóxicos seletivos para culturas pode ser através da avaliação de características fotossintéticas de plantas após aplicação de herbicidas. Objetivou-se com este trabalho avaliar os efeitos dos herbicidas fluazifop-p-butyl e fomesafen, aplicados isoladamente e em mistura, sobre as variáveis fotossintéticas de cinco cultivares de mandioca (Cacau- UFV, Platina, Coqueiro, Coimbra e IAC-12. Os tratamentos foram aplicados aos 30 dias após o plantio, quando as plantas de mandioca apresentavam aproximadamente 30 cm de

  7. Nodulação e crescimento de variedades de soja RR sob aplicação de glyphosate, fluazifop-p-butyl e fomesafen GR glycine max nodulation and growth under glyphosate, fluazifop-p-butyl and fomesafen aplication

    Directory of Open Access Journals (Sweden)

    E.C. Dvoranen

    2008-01-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos causados por aplicações dos herbicidas glyphosate, fluazifop-p-butyl e fomesafen, em diferentes formas de aplicação, sobre a nodulação e o crescimento inicial de duas variedades de soja RR. Os tratamentos foram organizados em arranjo fatorial 6 x 2, no qual foram avaliadas seis formas de aplicação de herbicida (testemunha sem herbicida, aplicação seqüencial de fomesafen/fomesafen, aplicação seqüencial de fomesafen/[fomesafen+fluazifop-p-butyl], fluazifop-p-butyl em aplicação única, aplicação seqüencial de glyphosate/glyphosate e glyphosate em aplicação única e duas variedades de soja (BRS 245 RR e BRS 247 RR. Com relação à nodulação, a aplicação seqüencial de fomesafen/fomesafen foi a forma mais seletiva. A variedade BRS 245 RR mostrou-se mais tolerante do que a variedade BRS 247 RR às aplicações dos herbicidas. Número e matéria seca de nódulos da variedade BRS 247 RR são reduzidos por aplicações em dose única de fluazifop-p-butyl e glyphosate.The objective of this work was to evaluate the effects of the herbicides glyphosate, fluazifop-p-butyl and fomesafen, applied by different methods, on nodulation and initial growth of two glyphosate-resistant (GR soybean varieties. Treatments were arranged in a 6 x 2 factorial, with six herbicide application methods (no-herbicide check, fomesafen/fomesafen sequential application, fomesafen/[fomesafen+fluazifop-p-butyl sequential application], fluazifop-p-butyl single application, glyphosate/glyphosate sequential application and glyphosate single application and two soybean varieties (BRS 245 RR and BRS 247 RR. Regarding soybean nodulation, fomesafen/fomesafen sequential application was the most selective herbicide application method. Variety BRS 245 RR was more tolerant than BRS 247 RR to the herbicides evaluated. Number and dry weight of nodules decreased after single applications of fluazifop-p-butyl and glyphosate.

  8. Distribution of methyl tert-butyl ether (MTBE) and selected water-quality constituents in the surficial aquifer at the Dover National Test Site, Dover Air Force Base, Delaware, 2001

    Science.gov (United States)

    Stewart, Marie; Guertal, William R.; Barbaro, Jeffrey R.; McHale, Timothy J.

    2004-01-01

    A joint study by the Dover National Test Site, Dover Air Force Base, Delaware, and the U.S. Geological Survey was conducted from June 27 through July 18, 2001, to determine the spatial distribution of the gasoline oxygenate additive methyl tert-butyl ether and selected water-quality constituents in the surficial aquifer underlying the Dover National Test Site. This report provides a summary assessment of the distribution of methyl tert-butyl ether and a preliminary screening of selected constituents that may affect natural attenuation and remediation demonstrations at the Dover National Test Site. The information gathered during this study is designed to assist potential remedial investigators who are considering conducting a methyl tert-butyl ether remedial demonstration at the test site. In addition, the study supported a planned enhanced bioremediation demonstration and assisted the Dover National Test Site in identifying possible locations for future methyl tert-butyl ether remediation demonstrations. A direct-push drill rig was used to collect a total of 147 ground-water samples (115 VOC samples and 32 quality-assurance samples) at varying depths. Volatile organic compounds were above the method reporting limits in 59 of the 115 ground-water samples. The concentrations ranged from below detection limits to maximum values of 12.4 micrograms per liter of cis-1,2-dichloro-ethene, 1.14 micrograms per liter of trichloro-ethene, 2.65 micrograms per liter of tetrachloro-ethene, 1,070 micrograms per liter of methyl tert-butyl ether, 4.36 micrograms per liter of benzene, and 1.8 micrograms per liter of toluene. Vinyl chloride, ethylbenzene, p,m-xylene, and o-xylene were not detected in any of the samples collected during this investigation. Methyl tert-butyl ether was detected in 47 of the 115 ground-water samples. The highest concentrations of methyl tert-butyl ether were detected in the surficial aquifer from ?4.6 to 6.4 feet mean sea level; however, methyl tert-butyl

  9. Study of an aquifer contaminated by ethyl tert-butyl ether (ETBE): Site characterization and on-site bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Fayolle-Guichard, Francoise, E-mail: francoise.fayolle@ifpen.fr [IFP Energies nouvelles, 1 et 4 avenue de Bois-Preau, 92852 Rueil-Malmaison (France); Durand, Jonathan [Institut EGID Bordeaux 3, 1 Allee Daguin 33607 Pessac Cedex (France); SERPOL, 2 chemin du Genie, BP 80, 69633 Venissieux Cedex (France); Cheucle, Mathilde [SERPOL, 2 chemin du Genie, BP 80, 69633 Venissieux Cedex (France); Rosell, Monica [Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig (Germany); Michelland, Rory Julien [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1, Villeurbanne (France); CNRS, UMR5557, Ecologie Microbienne (France); Tracol, Jean-Philippe [SERPOL, 2 chemin du Genie, BP 80, 69633 Venissieux Cedex (France); Le Roux, Francoise [IFP Energies nouvelles, 1 et 4 avenue de Bois-Preau, 92852 Rueil-Malmaison (France); Grundman, Genevieve [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1, Villeurbanne (France); CNRS, UMR5557, Ecologie Microbienne (France); Atteia, Olivier [Institut EGID Bordeaux 3, 1 Allee Daguin 33607 Pessac Cedex (France); Richnow, Hans H. [Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig (Germany); Dumestre, Alain [SERPOL, 2 chemin du Genie, BP 80, 69633 Venissieux Cedex (France); and others

    2012-01-30

    Highlights: Black-Right-Pointing-Pointer Ethyl tert-butyl ether (ETBE) (>300 mg L{sup -1}) found in a groundwater (gas-station). Black-Right-Pointing-Pointer No significant carbon or hydrogen isotopic fractionation of ETBE along the plume. Black-Right-Pointing-Pointer MC-IFP culture degraded ETBE (0.91 mg L{sup -1} h{sup -1}) and BTEX (0.64 mg L{sup -1} h{sup -1}). Black-Right-Pointing-Pointer A pilot plant (2 m{sup 3}) inoculated with MC-IFP degraded ETBE in groundwater (15 Degree-Sign C). Black-Right-Pointing-Pointer ethB gene (ETBE biodegradation) amplified during bioaugmentation (5 Multiplication-Sign 10{sup 6}ethB gene copies L{sup -1}). - Abstract: Ethyl tert-butyl ether (ETBE) was detected at high concentration (300 mg L{sup -1}) in the groundwater below a gas-station. No significant carbon neither hydrogen isotopic fractionation of ETBE was detected along the plume. ETBE and BTEX biodegradation capacities of the indigenous microflora Pz1-ETBE and of a culture (MC-IFP) composed of Rhodococcus wratislaviensis IFP 2016, Rhodococcus aetherivorans IFP 2017 and Aquincola tertiaricarbonis IFP 2003 showed that ETBE and BTEX degradation rates were in the same range (ETBE: 0.91 and 0.83 mg L{sup -1} h{sup -1} and BTEX: 0.64 and 0.82 mg L{sup -1} h{sup -1}, respectively) but tert-butanol (TBA) accumulated transiently at a high level using Pz1-ETBE (74 mg L{sup -1}). An on-site pilot plant (2 m{sup 3}) filled with polluted groundwater and inoculated by MC-IFP, successfully degraded four successive additions of ETBE and gasoline. However, an insignificant ETBE isotopic fractionation was also accompanying this decrease which suggested the involvement of low fractionating-strains using EthB enzymes, but required of additional proofs. The ethB gene encoding a cytochrome P450 involved in ETBE biodegradation (present in R. aetherivorans IFP 2017) was monitored by quantitative real-time polymerase chain reaction (q-PCR) on DNA extracted from water sampled in the pilot plant

  10. Phase equilibria study of the binary systems (1-butyl-3-methylimidazolium thiocyanate ionic liquid + organic solvent or water).

    Science.gov (United States)

    Domańska, Urszula; Laskowska, M; Pobudkowska, Aneta

    2009-05-07

    (Solid + liquid) phase equilibria (SLE) for the binary systems, ionic liquid (IL) 1-butyl-3-methylimidazolium thiocyanate [BMIM][SCN] with an alcohol (1-octanol, 1-nonanol, 1-decanol, 1-undecanol, or 1-dodecanol) or water, and (liquid + liquid) phase equilibria (LLE) for the binary systems of [BMIM][SCN] with an alkane (n-hexane, n-heptane, n-octane, n-nonane, or n-decane), benzene, an alkylbenzenes (toluene or ethylbenzene), tetrahydrofuran (THF), cycloalkanes (cyclohexane or cycloheptane), or ethers (di-n-propyl ether, di-n-butyl ether, di-n-pentyl ether, n-butylmethyl ether, tert-butylmethyl ether (MTBE), or tert-butylethyl ether (ETBE)) have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from 250 to 430 K. In the case of systems IL + alkane, cycloalkane, or ether, the mutual immiscibility with an upper critical solution temperature (UCST) was detected, and in the systems of IL + benzene, alkylbenzene, or THF, the mutual immiscibility with a lower critical solution temperature (LCST) was observed. UV-vis spectroscopy was used to determine the very small compositions of the IL in the n-hexane (about 2 x 10(-5) IL mole fraction), benzene (about 2 x 10(-3) IL mole fraction), cyclohexane (about 2 x 10(-5) IL mole fraction), and THF (about 1.2 x 10(-2) IL mole fraction). For the binary systems containing alcohol, it was noticed that with increasing chain length of an alcohol, the solubility decreases. The basic thermal properties of the pure IL, that is, the glass-transition temperature as well as the heat capacity at the glass-transition temperature, have been measured using a differential scanning microcalorimetry technique (DSC). Decomposition of the IL was detected by the simultaneous TG/DTA experiments. Well-known UNIQUAC, Wilson, and NRTL equations have been used to correlate the experimental SLE data sets for alcohols and water. For the systems containing immiscibility gaps {IL + alkane

  11. Comparison of scaffold-enhanced albumin and n-butyl-cyanoacrylate adhesives for joining of tissue in a porcine model

    Science.gov (United States)

    McNally-Heintzelman, Karen M.; Riley, Jill N.; Heintzelman, Douglas L.

    2003-06-01

    An ex vivo study was conducted to compare the tensile strength of tissue samples repaired using three different techniques: (i) application of a scaffold-enhanced light-activated albumin protein solder, (ii) application of a scaffold-enhanced n-butyl-cyanoacrylate adhesive, and (iii) repair via conventional suture technique. Biodegradable polymer scaffolds of controlled porosity were fabricated with poly(L-lactic-co-glycolic acid) and salt particles using a solvent-casting and particulate-leaching technique. Group I porous scaffolds were doped with protein solder composed of 50%(w/v) bovine serum albumin solder and 0.5mg/ml indocyanine green dye mixed in deionized water, and activated with an 808-nm diode laser. Group II scaffolds were doped with n-butyl-cyanoacrylate, and required no light-activation. No stay sutures were required for Group I or II experiments. Group III repairs were performed using a single 4-0 suture. Thirteen organs were tested ranging from skin to liver to the small intestine, as well as the coronary, pulmonary, carotid, femoral and splenic arteries. Acute breaking strengths were measured and the data were analyzed by Student"s T-test. Using the protein solder of Group I, repairs formed on the ureter were most successful followed by small intestine, sciatic nerve, spleen, atrium, kidney, muscle, skin and ventricle. The strongest vascular repairs were achieved in the carotid artery and femoral artery. Overall, the tensile strength of Group III repairs performed via suture techniques were equivalent in magnitude to that of Group I repairs, however, a larger variance was observed in the suture repair group. Group II repairs utilizing the cyanoacrylate-doped scaffold all performed extremely well. Bonds formed using the Group II adhesive were approximately 30% stronger than Group I and III organ repairs and approximately 20% stronger than Group I and III vascular repairs. Application of the polymer scaffold assists in tissue alignment and reduces

  12. Solid-Liquid Equilibria of Musk Ketone, Musk Xylene and 1,3-Dimethyl-2,4-Dinitro-5-Tert-Butyl Benzene

    Institute of Scientific and Technical Information of China (English)

    曲红梅; 白鹏; 杨志才; 余国琮

    2004-01-01

    The solid-liquid equilibria of musk ketone + musk xylene, musk xylene+1,3-dimethyl-2,4-dinitro-5-tert-butyl benzene are measured by differential scanning calorimeter (DSC), these systems are proved to be simple eutectics. Moreover the melting points and the fusion enthalpies of musk ketone, musk xylene and 1,3-dimethyl-2,4-dinitro-5-tert-butyl benzene are also measured by the DSC. These solid-liquid equilibrium data and the heats of fusion are reported for the first time. Then UNIFAC model is used to correlate the solid-liquid equilibrium data.It is shown that the solid-liquid equilibria of musk systems can be predicted bv the UNIFAC model.

  13. SYNTHESIS AND CHARACTERISTICS OF GRAFT COPOLYMERS OF POLY (BUTYL ACRYLATE AND CELLULOSE WITH ULTRASONIC PROCESSING AS A MATERIAL FOR OIL ABSORPTION

    Directory of Open Access Journals (Sweden)

    Ping Qu

    2011-11-01

    Full Text Available A series of materials used for oil absorption based on cellulose fiber grafted with butyl acrylate (BuAc have been prepared by radical polymerization under ultrasonic waves processing. Effects of ultrasonic dose for the maximum graft yield were considered. The dependency of optimum conditions for oil absorption rate on parameters such as ultrasonic processing time and ultrasonic power were also determined. Fourier infrared (FT-IR analysis was used to confirm the chemical reaction taking place between cellulose and butyl acrylate. The thermogravimetric behavior of the graft copolymer was characterized by thermogravimetric analysis (TGA. Scanning electron microscope (SEM analysis was used to determine the surface structure of the grafted material. With the increase of the ultrasonic treatment dose, the surface of the ultrasonic processed material became more regular, and the material was transformed into a homogeneous network polymer having a good structure and good adsorbing ability.

  14. N-Substituted-2-butyl-5-chloro-3H-imidazole-4-carbaldehyde derivatives as anti-tumor agents against Ehrlich ascites tumor cells in vivo.

    Science.gov (United States)

    Kumar, C Anil; Swamy, S Nanjunda; Gaonkar, S L; Basappa; Salimath, Bharathi P; Rangappa, Kanchugarakoppal S

    2007-05-01

    A new series of N-substituted 2-butyl-5-chloro-3H-imidazole-4-carbaldehyde derivatives were synthesized by using the different bioactive heteroaralkyl halides with 2-butyl-4-chloro-1H-imidazole-5-carbaldehyde in presence of powdered potassium carbonate in DMF medium. These compounds were screened for their antitumor activity. Our results show that treatment of imidazole derivatives inhibit proliferation EAT cells, decreases the ascites volume and increases the survivability of the animals in vivo. These compounds also inhibited the cellular proliferation of HUVEC cells in vitro by MTT assay. Further, these compounds could induce apoptosis, which is evident by the nuclear condensation of imidazole derivatives treated EAT cells in vivo by the cytological analysis. We have identified that pyrrolidine substituted imidazole derivative as potent anti-tumor compound. These inhibitors could represent as promising candidates for anticancer therapies, where the formation of peritoneal malignant ascites is a major cause of morbidity and mortality.

  15. The study on grafting comonomer of n-butyl acrylate and styrene onto poly(ethylene terephthalate) film by gamma-ray induced graft copolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Ping Xiang; Wang Mozhen [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Ge Xuewu, E-mail: xwge@ustc.edu.c [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2010-09-15

    Poly(ethylene terephthalate) (PET) film was successfully grafted with n-butyl acrylate and styrene comonomer through gamma-ray induced graft copolymerization. The degree of grafting (DG) and the composition of grafted side chain were characterized by {sup 1}H NMR. It was found that St can inhibit the homopolymerization of BA effectively and increase the DG when the concentration of comonomer mixture is kept constant. The proportion of St to BA in grafted side chain has a positive dependence on the feed ratio of St, which ultimately approaches the feed ratio. The thermal properties of poly(ethylene terephthalate)-graft-poly(n-butyl acrylate-co-styrene) (PET-g-P(BA-co-St)) films were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The T{sub g} of PET decreases with the DG, indicating that the grafted P(BA-co-St) copolymer has good compatibility with PET backbone.

  16. SYNTHESIS AND FREE RADICAL RING-OPENING POLYMERIZATION OF 2 - METHYL-AND 2- METHYL- 9- n- BUTYL- (- 7- METHYLENE- 1,4,6 - TRIOXASPIRO (4, 4 )NONANE )

    Institute of Scientific and Technical Information of China (English)

    PAN Caiyuan; WANG Yin

    1989-01-01

    This paper describes the synthesis and free radical ring- opening polymerization of 2 - methyl-and2 - methyl - 9 - n - butyl ( - 7 - methylene - 1,4, 6 - trioxaspiro (4, 4 ) nonane ). The structures of the two polymers were verified by IR, 1H and 13C NMR spectra. The substituent on 9-position of 7-methylene- trioxaspiro (4, 4 ) nona ne affects the structure of polymer and polymerization activity. The polymerization mechanism is discussed .

  17. Effects of the Ionic Liquid 1-Butyl-3-methylimidazolium Chloride on the Growth and Ethanol Fermentation of Saccharomyces cerevisiae AY92022

    OpenAIRE

    Zhu, S.; Yu, P.; Tong, Y; Chen, R.; Lv, Y.; Zhang, R.; Lei,M.; Ji, J; Chen, Q; Y Wu

    2012-01-01

    Use of ionic liquids has provided a potential effective alternative in the conversion of carbohydrates in lignocellulosic materials into fermentable sugars for ethanol production. To evaluate how the remained ionic liquids in the fermentable sugars affect the subsequent ethanol fermentation process, the effects of ionic liquid 1- butyl-3-methylimidazolium chloride ([Bmim]Cl) in the medium at different concentrations from 10–3 to 1 g L–1 on the morphological structure, growth and ethanol ferme...

  18. 2-(4-Bromobenzyl-5,11,17,23-tetra-tert-butyl-25,26,27,28-tetramethoxycalix[4]arene

    Directory of Open Access Journals (Sweden)

    Conrad Fischer

    2009-07-01

    Full Text Available In the title compound, C55H69BrO4, the calixarene molecule displays a `partial cone' conformation bearing the lateral substituent in a sterically favorable equatorial arrangement between two syn-orientated arene units. The crystal packing is stabilized by weak C—H...π contacts, involving one tert-butyl group, and π–stacking interactions of the lateral bromobenzene units [centroid–centroid distance = 3.706 (1 Å].

  19. Optical and charge transport properties of N-butyl-1,8-naphthalimide derivatives as organic light-emitting materials: A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Fuyu [College of Physical and Electronic and Information Engineering, Chifeng University, Chifeng 024000 (China); Jin, Ruifa, E-mail: Ruifajin@163.com [College of Chemistry and Chemical Engineering, Chifeng University, Chifeng 024000 (China)

    2014-05-01

    A series of N-butyl-1,8-naphthalimide derivatives have been designed to explore their optical, electronic, and charge transport properties as charge transport and/or luminescent materials for organic light-emitting diodes (OLEDs). The frontier molecular orbitals (FMOs) analysis has turned out that the vertical electronic transitions of absorption and emission are characterized as intramolecular charge transfer (ICT). The calculated results show that the optical and electronic properties of N-butyl-1,8-naphthalimide derivatives are affected by the substituent groups in 4-position of 1,8-naphthalimide ring. Our results suggest that N-butyl-1,8-naphthalimide derivatives with biphenyl (1), 2-phenylthiophene (2), 2-(thiophen-2-yl)thiophene (3), 2,3-dihydrothieno[3,4-b][1,4]dioxine (4), 2-phenyl-1,3,4-oxadiazole (5), benzo[c][1,2,5]thiadiazole (6), benzo[c]thiophene (7), and benzo[d]thieno[3,2-b]thiophene (8) fragments are expected to be promising candidates for luminescent materials for OLEDs, particularly for 1–3 and 5. In addition, 7 and 8 can be used as promising hole transport materials for OLEDs. - Highlights: • A series of N-butyl-1,8-naphthalimide derivatives is investigated. • Optical and electronic properties are affected by their substituent groups. • The vertical electronic transitions are characterized as intramolecular charge transfer. • All derivatives are promising luminescent materials for OLEDs. • Some derivatives can be used as promising hole transport materials for OLEDs.

  20. R-(+)-ABP a novel derivative of 3-n-butyl-phthalide possesses anti-convulsant and neuroprotective properties in rodents

    Institute of Scientific and Technical Information of China (English)

    ELESTAGE; A.ROGER; L.DANOBER; ERENARD; X-Q.PENG; Z.GUO; J.T.ZHANG

    2004-01-01

    ABP is a novel phthalide derivative of 3-n-butyl-phthalide (NBP) synthesized at the Beijing Institute of Materia Medica.NBP was isolated from several plants including Apium graveolens Linn. The juice squeezed from fresh celery leaves has long been used in Southeastern China for the treatment of epilepsy, and NBP has been reported to possess anti-convulsant properties (Drugs Future 2000; 25: 16-23). The present study

  1. Folate-decorated chitosan/doxorubicin poly(butyl)cyanoacrylate nanoparticles for tumor-targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Duan Jinghua [Xiangya Hospital, Central South University, Hepatobiliary and Enteric Surgery Research Center (China); Liu Mujun [Central South University, School of Biological Science and Technology (China); Zhang Yangde; Zhao Jinfeng; Pan Yifeng [Xiangya Hospital, Central South University, Hepatobiliary and Enteric Surgery Research Center (China); Yang Xiyun, E-mail: bax_2007@126.com [Central South University, School of Metallurgical Science and Engineering (China)

    2012-03-15

    A novel chitosan coated poly(butyl cyanoacrylate) (PBCA) nanoparticles loaded doxorubicin (DOX) were synthesized and then conjugated with folic acid to produce a folate-targeted drug carrier for tumor-specific drug delivery. Prepared nanoparticles were surface modified by folate for targeting cancer cells, which is confirmed by FTIR spectroscopy and characterized for shape, size, and zeta potential measurements. The size and zeta potential of prepared DOX-PBCA nanoparticles (DOX-PBCA NPs) were almost 174 {+-} 8.23 nm and +23.14 {+-} 4.25 mV, respectively with 46.8 {+-} 3.32% encapsulation capacity. The transmission electron microscopy study revealed that preparation allowed the formation of spherical nanometric and homogeneous. Fluorescent microscopy imaging and flow cytometry analysis revealed that DOX-PBCA NPs were endocytosed into MCF-7 cells through the interaction with overexpressed folate receptors on the surface of the cancer cells. The results demonstrate that folate-conjugated DOX-PBCA NPs drug delivery system could provide increased therapeutic benefit by delivering the encapsulated drug to the folate receptor positive cancer cells.

  2. A Study of the Catalysts for the Complete Oxidation of Low Concentration Ethyl Acetate and n-Butyl Acetate

    Institute of Scientific and Technical Information of China (English)

    DUAN; ZhiYing

    2001-01-01

    In this work, we have synthesized mixed oxides catalysts supported on γ-Al2O3,using some base metals such as La、 Sr、 Ce、 Ni、 Cu. At the space velocity of 56,000h-1 and at some range of concentration, the complete conversion temperatures( ≥ 98% )of Ethyl acetate and n-butyl acetate are 260℃ and 250℃ respectively. The work has an excellent prospect of industrial application.  I will introduce the experiment and results from the following tluee aspects. According to Figure 1, X-ray diffraction pattern of the catalyst have shown not only perovskite structure but also much independent CeO2 phase. During the preparation, the CeO2 was coated over support γ-A12O3 for the better Oxygen storage capacity .By co1mparison, we found that the activity of the catalyst with CeO2 was higher than the activity of the catalyst without CeO2.……

  3. Solvent Extraction of Tellurium from Chloride Solutions Using Tri-n-butyl Phosphate: Conditions and Thermodynamic Data

    Directory of Open Access Journals (Sweden)

    Dongchan Li

    2014-01-01

    Full Text Available The extractive separation of tellurium (IV from hydrochloric acid media with tri-n-butyl phosphate (TBP in kerosene was investigated. The dependence on the extraction of tellurium species, concentrations of tellurium and TBP, extraction time and stage, organic/aqueous ratio, and interferences from coexist metallic ions were examined and are discussed. Besides, the stripping agent and stripping time were also studied. It was found that the extraction reaction corresponds to the neutral complex formation mechanism and the extracted species is TeCl4·3TBP and that the extraction process is exothermic. The thermodynamic parameters of enthalpy ΔH, entropy ΔS, and free energy ΔG of the extraction process were evaluated at −26.2 kJ·mol−1, −65.6 J·mol−1·K−1, and −7.0 kJ·mol−1, respectively at 293 K.

  4. Calorimetric determination of the enthalpy of 1-butyl-3-methylimidazolium bromide synthesis: a key quantity in thermodynamics of ionic liquids.

    Science.gov (United States)

    Paulechka, Yauheni U; Kabo, Andrey G; Blokhin, Andrey V

    2009-11-05

    The enthalpy of the 1-butyl-3-methylimidazolium bromide [C(4)mim]Br ionic liquid synthesis reaction 1-methylimidazole (liq) + 1-bromobutane (liq) --> [C(4)mim]Br (liq) was determined in a homemade small-volume isoperibol calorimeter to be Delta(r)H degrees (298) = -87.7 +/- 1.6 kJ x mol(-1). The activation energy for this reaction in a homogeneous system E(A) = 73 +/- 4 kJ x mol(-1) was found from the results of calorimetric measurements. The formation enthalpies for the crystalline and liquid [C(4)mim]Br were determined from the calorimetric data: Delta(f)H degrees (298)(cr) = -178 +/- 5 kJ x mol(-1) and Delta(f)H degrees (298)(liq) = -158 +/- 5 kJ x mol(-1). The ideal-gas formation enthalpy of this compound Delta(f)H degrees (298)(g) = 16 +/- 7 kJ x mol(-1) was calculated using the methods of quantum chemistry and statistical thermodynamics. The vaporization enthalpy of [C(4)mim]Br, Delta(vap)H degrees (298) = 174 +/- 9 kJ x mol(-1), was estimated from the experimental and calculated formation enthalpies. It was demonstrated that vapor pressure of this ionic liquid cannot be experimentally determined.

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

    Science.gov (United States)

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

    2016-02-06

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

  6. Determination of the solubility parameter of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate by inverse gas chromatography.

    Science.gov (United States)

    Ma, Xiaohong; Wang, Qiang; Li, Xiaoping; Tang, Jun; Zhang, Zhengfang

    2015-11-01

    Thermodynamic properties of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] BF4) were determined via inverse gas chromatography (IGC). Two groups of solvents with different chemical natures and polarities were used to obtain information about [BMIM] BF4-solvent interactions. The specific retention volume, molar heat of sorption, weight fraction activity coefficient, Flory-Huggins interaction parameter as well as solubility parameter were also determined in a temperature range of 333 - 373 K. The results showed that the selected solvents n-C10 to n-C12, carbon tetrachloride, cyclohexane and toluene were poor solvents for [BMIM] BF4, while dichloromethane, acetone, chloroform, methyl acetate, ethanol and methanol were favorite solvents for [BMIM] BF4. In addition, the solubility parameter of [ BMIM] BF4 was determined as 23.39 (J/cm3)0.5 by the extrapolation at 298 K. The experiment proved that IGC was a simple and accurate method to obtain the thermodynamic properties of ionic liquids. This study could be used as a reference to the application and research of the ionic liquids.

  7. A Study of the Catalysts for the Complete Oxidation of Low Concentration Ethyl Acetate and n-Butyl Acetate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ In this work, we have synthesized mixed oxides catalysts supported on γ-Al2O3,using some base metals such as La、 Sr、 Ce、 Ni、 Cu. At the space velocity of 56,000h-1 and at some range of concentration, the complete conversion temperatures( ≥ 98% )of Ethyl acetate and n-butyl acetate are 260℃ and 250℃ respectively. The work has an excellent prospect of industrial application. I will introduce the experiment and results from the following tluee aspects. According to Figure 1, X-ray diffraction pattern of the catalyst have shown not only perovskite structure but also much independent CeO2 phase. During the preparation, the CeO2 was coated over support γ-A12O3 for the better Oxygen storage capacity .By co1mparison, we found that the activity of the catalyst with CeO2 was higher than the activity of the catalyst without CeO2.

  8. Measurement and Modeling of Vapor-Liquid Equilibrium for Ternary System Water+2-Propanol+1-Butyl-3-methylimidazolium Chloride

    Institute of Scientific and Technical Information of China (English)

    邓东顺; 乔玉珍; 姬登祥; 葛筠; 章连众

    2014-01-01

    Vapor-liquid equilibrium (VLE) data for water+2-propanol+1-butyl-3-methylimidazolium chloride ([bmim]Cl) were measured. Six sets of complete T, x, y data are reported, in which the 2-propanol mole fraction on IL-free basis is fixed separately at 0.1, 0.2, 0.4, 0.6, 0.8, and approximate 0.98, while the IL mass fraction is varied from 0.1 to 0.8, in an interval of 0.1. The non-random-two-liquid (NRTL) and electrolyte non-random-two-liquid (eNRTL) equations are used to correlate the experimental data with satisfactory results. The ternary VLE behavior is also modeled with the parameters obtained by correlating two data sets, in which the mole fraction of 2-propanol on IL-free basis is approximately 0.1 and 0.98. In this way, the six sets of data are reproduced satisfactorily. With the eNRTL model, the root-mean-square deviation for temperature is 0.82 K and that for vapor-phase mole fraction is 0.0078. The influences of IL on activity coefficients and relative volatility of the volatile components are also graphically illustrated.

  9. Selenium methylselenocysteine protects human hepatoma HepG2 cells against oxidative stress induced by tert-butyl hydroperoxide.

    Science.gov (United States)

    Cuello, Susana; Ramos, Sonia; Mateos, Raquel; Martín, M Angeles; Madrid, Yolanda; Cámara, Carmen; Bravo, Laura; Goya, Luis

    2007-12-01

    Selenium methylselenocysteine (Se-MeSeCys) is a common selenocompound in the diet with a tested chemopreventive effect. This study investigated the potential protective effect of Se-MeSeCys against a chemical oxidative stress induced by tert-butyl hydroperoxide (t-BOOH) on human hepatoma HepG2 cells. Speciation of selenium derivatives by liquid chromatography-inductively coupled plasma mass spectrometry depicts Se-MeSeCys as the only selenocompound in the cell culture. Cell viability (lactate dehydrogenase) and markers of oxidative status--concentration of reduced glutathione (GSH) and malondialdehyde (MDA), generation of reactive oxygen species (ROS) and activity of the antioxidant enzymes glutathione peroxidase (GPx) and glutathione reductase (GR)--were evaluated. Pretreatment of cells with Se-MeSeCys for 20 h completely prevented the enhanced cell damage, MDA concentration and GR and GPx activity and the decreased GSH induced by t-BOOH but did not prevent increased ROS generation. The results show that treatment of HepG2 cells with concentrations of Se-MeSeCys in the nanomolar to micromolar range confers a significant protection against an oxidative insult.

  10. Efficient hydrolysis of cellulose over a magnetic lignin-derived solid acid catalyst in 1-butyl-3-methylimidazolium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Lei; Wu, Zhen; Xu, Jiaxing; Zhou, Shouyong; Tang, Guodong [Huaiyin Normal University, Huaian (China)

    2016-04-15

    A green and efficient strategy for the hydrolysis of cellulose was developed by using a magnetic lignin-derived solid acid catalyst (MLC-SO{sub 3}H) in the presence of ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl). The results indicated that reaction temperature, reaction time, catalyst loading and water content have a big influence on the yield of total reducing sugars (TRS). By optimizing these reaction parameters, 69.3% TRS yield was observed at 140 .deg. C for 150 min with the addition of 40 wt% MLC-SO{sub 3}H and 1 wt% water. More importantly, MLC-SO{sub 3}H could be easily separated from the reaction mixture with an external magnet and could be repeatedly used five times without an obvious loss of catalytic activity, demonstrating that it possessed excellent recyclability. Furthermore, a plausible mechanism involving three consecutive processes of dissolution, adsorption and catalysis for the hydrolysis of cellulose in [BMIM]Cl over a catalyst of MLC-SO{sub 3}H was also proposed.

  11. Molecular dynamics simulations of n-hexane at 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide interface

    Science.gov (United States)

    Lísal, Martin; Izák, Pavel

    2013-07-01

    Molecular dynamics simulations of n-hexane adsorbed onto the interface of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([bmim][Tf2N]) are performed at three n-hexane surface densities, ranged from 0.7 to 2.3 μmol/m2 at 300 K. For [bmim][Tf2N] room-temperature ionic liquid, we use a non-polarizable all-atom force field with the partial atomic charges based on ab initio calculations for the isolated ion pair. The net charges of the ions are ±0.89e, which mimics the anion to cation charge transfer and polarization effects. The OPLS-AA force field is employed for modeling of n-hexane. The surface tension is computed using the mechanical route and its value decreases with increase of the n-hexane surface density. The [bmim][Tf2N]/n-hexane interface is analyzed using the intrinsic method, and the structural and dynamic properties of the interfacial, sub-interfacial, and central layers are computed. We determine the surface roughness, global and intrinsic density profiles, and orientation ordering of the molecules to describe the structure of the interface. We further compute the survival probability, normal and lateral self-diffusion coefficients, and re-orientation correlation functions to elucidate the effects of n-hexane on dynamics of the cations and anions in the layers.

  12. Cellulose nanocrystals' production in near theoretical yields by 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO4)-mediated hydrolysis.

    Science.gov (United States)

    Mao, Jia; Heck, Barbara; Reiter, Günter; Laborie, Marie-Pierre

    2015-03-06

    We report on near theoretical yield production of cellulose I nanocrystals (CNCs) using a two-step hydrolysis with the mildly acidic ionic liquid (IL) 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO4) in aqueous solution from common cellulosic sources. Two successive Taguchi experimental plans were performed to evaluate the impact of selected reaction parameters (T, t, H2O:IL ratio) and their interactions on the CNCs' yield from bleached softwood kraft pulp (SWP), bleached hardwood kraft pulp (HWP) and microcrystalline cellulose (MCC). With these experimental plans, the molar yield for extraction of nanocrystals was optimized to near theoretical levels, reaching 57.7±3.0%, 57.0±2.0%, and 75.6±3.0%, for SWP, HWP and MCC, respectively. The reaction yields corresponded to a relative crystalline region recovery of 84.1±5.3%, 71.7±1.3%, 76.0±2.0% from SWP, HWP and MCC, respectively. The collected nanocrystals exhibited high aspect ratios (36-43), negligible sulfur content (0.02-0.21%) and high solvent dispersibility in comparison to those obtained with the traditional sulfuric acid method. Additionally these near theoretical yields were achieved for mild reaction conditions with the combined severity factor of 2 and 3 for MCC and pulp, respectively. Overall this two-stage IL-mediated preparation of nanocrystals combines the advantages of achieving high product quality, high reaction yields and mild conditions.

  13. Molecular dynamics simulations of n-hexane at 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide interface

    Energy Technology Data Exchange (ETDEWEB)

    Lisal, Martin [Institute of Chemical Process Fundamentals of the ASCR, v. v. i., 165 02 Prague 6-Suchdol (Czech Republic); Department of Physics, Faculty of Science, J. E. Purkinje University, 400 96 Usti n. Lab. (Czech Republic); Izak, Pavel [Institute of Chemical Process Fundamentals of the ASCR, v. v. i., 165 02 Prague 6-Suchdol (Czech Republic)

    2013-07-07

    Molecular dynamics simulations of n-hexane adsorbed onto the interface of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([bmim][Tf{sub 2}N]) are performed at three n-hexane surface densities, ranged from 0.7 to 2.3 {mu}mol/m{sup 2} at 300 K. For [bmim][Tf{sub 2}N] room-temperature ionic liquid, we use a non-polarizable all-atom force field with the partial atomic charges based on ab initio calculations for the isolated ion pair. The net charges of the ions are {+-}0.89e, which mimics the anion to cation charge transfer and polarization effects. The OPLS-AA force field is employed for modeling of n-hexane. The surface tension is computed using the mechanical route and its value decreases with increase of the n-hexane surface density. The [bmim][Tf{sub 2}N]/n-hexane interface is analyzed using the intrinsic method, and the structural and dynamic properties of the interfacial, sub-interfacial, and central layers are computed. We determine the surface roughness, global and intrinsic density profiles, and orientation ordering of the molecules to describe the structure of the interface. We further compute the survival probability, normal and lateral self-diffusion coefficients, and re-orientation correlation functions to elucidate the effects of n-hexane on dynamics of the cations and anions in the layers.

  14. Electrodeposition and magnetic characterization of iron and iron-silicon alloys from the ionic liquid 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate.

    Science.gov (United States)

    Giridhar, Pulletikurthi; Weidenfeller, Bernd; El Abedin, Sherif Zein; Endres, Frank

    2014-11-10

    The electrodeposition of soft magnetic iron and iron-silicon alloys for magnetic measurements is presented. The preparation of these materials in 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate, [Py1,4]TfO, at 100 °C with FeCl2 and FeCl2 +SiCl4 was studied by using cyclic voltammetry. Constant-potential electrolysis was carried out to deposit either Fe or FeSi, and deposits of approximately 10 μm thicknesses were obtained. By using scanning electron microscopy and X-ray diffraction, the microstructure and crystallinity of the deposits were investigated. Grain sizes in the nanometer regime (50-80 nm) were found and the presence of iron-silicon alloys was verified. Frequency-dependent magnetic polarizations, coercive forces, and power losses of some deposits were determined by using a digital hysteresis recorder. Corresponding to the small grain sizes, the coercive forces are around 950-1150 A m(-1) and the power losses were at 6000 J m(-3), which is much higher than in commercial Fe(3.2 wt %)Si electrical steel. Below a polarization of 1.8 T, the power losses are mainly caused by domain wall movements and, above 1.8 T, by rotation of magnetic moments as well as domain wall annihilation and recreation.

  15. Synthesis, Characterization and Application of 1-Butyl-3 Methylimidazolium Chloride as Green Material for Extractive Desulfurization of Liquid Fuel

    Directory of Open Access Journals (Sweden)

    Swapnil A. Dharaskar

    2013-01-01

    Full Text Available The possible application of imidazolium ionic liquids as energy-efficient green material for extractive deep desulfurization of liquid fuel has been investigated. 1-Butyl-3-methylimidazolium chloride [BMIM]Cl was synthesized by nucleophilic substitution reaction of n-methylimidazolium and 1-chlorobutane. Molecular structures of the ILs were confirmed by FTIR, 1H-NMR, and 13C-NMR. The thermal properties, conductivity, solubility, water content and viscosity analysis of [BMIM]Cl were carried out. The effects of reaction time, reaction temperature, sulfur compounds, and recycling of IL without regeneration on dibenzothiophene removal of liquid fuel were presented. In the extractive desulfurization process, the removal of dibenzothiophene in n-dodecane using [BMIM]Cl was 81% with mass ratio of 1 : 1, in 30 min at 30°C under the mild reaction conditions. Also, desulfurization of real fuels with IL and multistage extraction were studied. The results of this work might offer significant insights in the perceptive use of imidazoled ILs as energy-efficient green material for extractive deep desulfurization of liquid fuels as it can be reused without regeneration with considerable extraction efficiency.

  16. Synthesis, characterization and application of 1-butyl-3 methylimidazolium chloride as green material for extractive desulfurization of liquid fuel.

    Science.gov (United States)

    Dharaskar, Swapnil A; Varma, Mahesh N; Shende, Diwakar Z; Yoo, Chang Kyoo; Wasewar, Kailas L

    2013-01-01

    The possible application of imidazolium ionic liquids as energy-efficient green material for extractive deep desulfurization of liquid fuel has been investigated. 1-Butyl-3-methylimidazolium chloride [BMIM]Cl was synthesized by nucleophilic substitution reaction of n-methylimidazolium and 1-chlorobutane. Molecular structures of the ILs were confirmed by FTIR, (1)H-NMR, and (13)C-NMR. The thermal properties, conductivity, solubility, water content and viscosity analysis of [BMIM]Cl were carried out. The effects of reaction time, reaction temperature, sulfur compounds, and recycling of IL without regeneration on dibenzothiophene removal of liquid fuel were presented. In the extractive desulfurization process, the removal of dibenzothiophene in n-dodecane using [BMIM]Cl was 81% with mass ratio of 1 : 1, in 30 min at 30°C under the mild reaction conditions. Also, desulfurization of real fuels with IL and multistage extraction were studied. The results of this work might offer significant insights in the perceptive use of imidazoled ILs as energy-efficient green material for extractive deep desulfurization of liquid fuels as it can be reused without regeneration with considerable extraction efficiency.

  17. The role of CT in evaluation of the effectiveness of embolisation of spinal dural arteriovenous fistulae with N -butyl cyanoacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Cognard, C. [Service de Neuroradiologie Charcot, Hopital de la Salpetriere, Paris (France); Miaux, Y. [Service de Neuroradiologie Charcot, Hopital de la Salpetriere, Paris (France); Pierot, L. [Service de Neuroradiologie Charcot, Hopital de la Salpetriere, Paris (France); Weill, A. [Service de Neuroradiologie Charcot, Hopital de la Salpetriere, Paris (France); Martin, N. [Service de Neuroradiologie Charcot, Hopital de la Salpetriere, Paris (France); Chiras, J. [Service de Neuroradiologie Charcot, Hopital de la Salpetriere, Paris (France)

    1996-10-01

    A failed embolisation of a spinal dural arteriovenous fistula (AVF), because a pedicular injection has not reached the initial venous compartment, must be identified immediately, to allow prompt surgery and thus avoid clinical deterioration. The purpose of our study was to determine the role of CT in confirming a complete cure just after embolisation with N -butyl cyanoacrylate (NBCA). Seven patients embolised for spinal dural AVFs with perimedullary venous drainage had an immediate postembolisation CT scan. In six patients a complete cure was achieved, with a normal postembolisation angiogram in five cases. Just after injection of NBCA, we were unable to determine on plain films whether or not the glue had reached the draining vein in six of seven cases. The postembolisation CT showed various patterns: in two cured patients, the glue was visible in the inner surface of the dura mater and therefore on the venous side. In five cases, the glue was approaching the dura mater around the cord or seemed to reach its surface: in the four patients cured, the glue column was 7-18 mm high, whereas it was less than 2 mm high in the patient with angiographic proof of recurrent fistula. The follow-up angiogram remains the only way to confirm a durable cure. We suggest that immediate postembolisation CT may help in assessing endovascular treatment of spinal dural AVFs. (orig.). With 4 figs., 2 tabs.

  18. Crystal structure of trans-N,N′-bis(3,5-di-tert-butyl-2-hydroxyphenyloxamide methanol monosolvate

    Directory of Open Access Journals (Sweden)

    Miguel-Ángel Velázquez-Carmona

    2016-07-01

    Full Text Available The here crystallized oxamide was previously characterized as an unsolvated species [Jímenez-Pérez et al. (2000. J. Organomet. Chem. 614–615, 283–293], and is now reported with methanol as a solvent of crystallization, C30H44N2O4·CH3OH, in a different space group. The introduction of the solvent influences neither the molecular symmetry of the oxamide, which remains centrosymmetric, nor the molecular conformation. However, the unsolvated molecule crystallized as an ordered system, while many parts of the solvated crystal are disordered. The hydroxy group in the oxamide is disordered over two chemically equivalent positions, with occupancies 0.696 (4:0.304 (4; one tert-butyl group is disordered by rotation about the C—C bond, and was modelled with three sites for each methyl group, each one with occupancy 1/3. Finally, the methanol solvent, which lies on a twofold axis, is disordered by symmetry. The disorder affecting hydroxy groups and the solvent of crystallization allows the formation of numerous supramolecular motifs using four hydrogen bonds, with N—H and O—H groups as donors and the oxamide and methanol molecule as acceptors.

  19. Molecular dynamics simulations of n-hexane at 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide interface.

    Science.gov (United States)

    Lísal, Martin; Izák, Pavel

    2013-07-07

    Molecular dynamics simulations of n-hexane adsorbed onto the interface of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([bmim][Tf2N]) are performed at three n-hexane surface densities, ranged from 0.7 to 2.3 μmol/m(2) at 300 K. For [bmim][Tf2N] room-temperature ionic liquid, we use a non-polarizable all-atom force field with the partial atomic charges based on ab initio calculations for the isolated ion pair. The net charges of the ions are ±0.89e, which mimics the anion to cation charge transfer and polarization effects. The OPLS-AA force field is employed for modeling of n-hexane. The surface tension is computed using the mechanical route and its value decreases with increase of the n-hexane surface density. The [bmim][Tf2N]/n-hexane interface is analyzed using the intrinsic method, and the structural and dynamic properties of the interfacial, sub-interfacial, and central layers are computed. We determine the surface roughness, global and intrinsic density profiles, and orientation ordering of the molecules to describe the structure of the interface. We further compute the survival probability, normal and lateral self-diffusion coefficients, and re-orientation correlation functions to elucidate the effects of n-hexane on dynamics of the cations and anions in the layers.

  20. Individual or synchronous biodegradation of di-n-butyl phthalate and phenol by Rhodococcus ruber strain DP-2

    Energy Technology Data Exchange (ETDEWEB)

    He, Zhixing; Niu, Chengzhen; Lu, Zhenmei, E-mail: lzhenmei@zju.edu.cn

    2014-05-01

    Highlights: • A Rhodococcus ruber strain degraded DBP and phenol. • Degradation kinetics of DBP or phenol fit modified first-order models. • Degradation interaction between DBP and phenol was studied by strain DP-2. • The degradation genes transcriptional were quantified by RT-qPCR. - Abstract: The bacterial strain DP-2, identified as Rhodococcus ruber, is able to effectively degrade di-n-butyl phthalate (DBP) and phenol. Degradation kinetics of DBP and phenol at different initial concentrations revealed DBP and phenol degradation to fit modified first-order models. The half-life of DBP degradation ranged from 15.81 to 27.75 h and phenol degradation from 14.52 to 45.52 h under the initial concentrations of 600–1200 mg/L. When strain DP-2 was cultured with a mixture of DBP (800 mg/L) and phenol (700 mg/L), DBP degradation rate was found to be only slightly influenced; however, phthalic acid (PA) accumulated, and phenol degradation was clearly inhibited during synchronous degradation. Transcriptional levels of degradation genes, phenol hydroxylase (pheu) and phthalate 3,4-dioxygenase (pht), decreased significantly more during synchronous degradation than during individual degradation. Quantitative estimation of individual or synchronous degradation kinetics is essential to manage mixed hazardous compounds through biodegradation in industrial waste disposal.

  1. Effects of N-n-butyl Haloperidol Iodide on Myocardial Ischemia/Reperfusion Injury and Egr-1 Expression in Rat

    Institute of Scientific and Technical Information of China (English)

    Yan-Mei ZHANG; Gang-Gang SHI; Zhao TANG; Jin-Hong ZHENG; Wei-Qiu LI; Fu-Xiao GUO; Qiang-Yong JIA

    2006-01-01

    We have previously shown that N-n-butyl haloperidol iodide (F2) derived from haloperidol reduces ischemia/reperfusion-induced myocardial injury by blocking intracellular Ca2+ overload. This study tested the hypothesis that cardio-protection with F2 is associated with an attenuation in the expression of early growth response gene 1 (Egr-1). In an in vivo rat model of 60 min coronary occlusion followed by 180 min of reperfusion, treatment with F2 significantly reduced myocardial injury evidenced by the reduction in release of plasma creatine kinase, myocardial creatine kinase isoenzyme and lactate dehydrogenase. In cultured neonatal rat cardiomyocytes of hypoxia for 3 h and reoxygenation for 1 h, F2 treatment attenuated necrotic and apoptotic cell death, as demonstrated by electron microscopy. Concomitant with cardio-protection by F2, the increased expression levels of Egr-1 mRNA and proteinwere significantly reduced in myocardial tissue and cultured cardiomyocytes as detected by reverse transcription-polymerase chain reaction, immunohistochemistry and immunocytochemistry. In conclusion, these results suggest that the protective effect of F2 on ischemia/reperfusion- or hypoxia/reoxygenation-induced myocardial injury might be partly mediated by downregulating Egr-1 expression.

  2. Methyl tert-butyl ether (MTBE) in public and private wells in New Hampshire: Occurrence, factors, and possible implications

    Science.gov (United States)

    Ayotte, J.D.; Argue, D.M.; McGarry, F.J.; Degnan, J.R.; Hayes, L.; Flanagan, S.M.; Helsel, D.R.

    2008-01-01

    Methyl tert-butyl ether (MTBE) concentrations ???0.2 ??g/L were found in samples of untreated water in 18% of public-supply wells (n = 284) and 9.1% of private domestic wells (n = 264) sampled in 2005 and 2006 in New Hampshire. In counties that used reformulated gasoline (RFG), MTBE occurred at or above 0.2 ??g/L in 30% of public- and 17% of private-supply wells. Additionally, 52% of public-supply wells collocated with fuel storage and 71% of mobile home park wells had MTBE. MTBE occurrence in public-supply wells was predicted by factors such as proximity to sources of fuel, land use, and population density, as well as low pH and distance from mapped lineaments. RFG use, land-use variables, and pH were important predictors of private-well MTBE occurrence. Variables representing sources of MTBE, such as the distance to known fuel sources, were not significant predictors of MTBE occurrence in private-supply wells. It is hypothesized that private wells may become contaminated from the collective effects of sources in high population areas and from undocumented incidental releases from onsite or proximal gasoline use. From 2003 to 2005, MTBE occurrence decreased in 63 public-supply wells and increased in 60 private-supply wells, but neither trend was statistically significant. ?? 2008 American Chemical Society.

  3. n-Butyl benzyl phthalate promotes breast cancer progression by inducing expression of lymphoid enhancer factor 1.

    Directory of Open Access Journals (Sweden)

    Tsung-Hua Hsieh

    Full Text Available Environmental hormones play important roles in regulating the expression of genes involved in cell proliferation, drug resistance, and breast cancer risk; however, their precise role in human breast cancer cells during cancer progression remains unclear. To elucidate the effect of the most widely used industrial phthalate, n-butyl benzyl phthalate (BBP, on cancer progression, we evaluated the results of BBP treatment using a whole human genome cDNA microarray and MetaCore software and selected candidate genes whose expression was changed by more than ten-fold by BBP compared with controls to analyze the signaling pathways in human breast cancer initiating cells (R2d. A total of 473 genes were upregulated, and 468 were downregulated. Most of these genes are involved in proliferation, epithelial-mesenchymal transition, and angiogenesis signaling. BBP induced the viability, invasion and migration, and tube formation in vitro, and Matrigel plug angiogenesis in vivo of R2d and MCF-7. Furthermore, the viability and invasion and migration of these cell lines following BBP treatment was reduced by transfection with a small interfering RNA targeting the mRNA for lymphoid enhancer-binding factor 1; notably, the altered expression of this gene consistently differentiated tumors expressing genes involved in proliferation, epithelial-mesenchymal transition, and angiogenesis. These findings contribute to our understanding of the molecular impact of the environmental hormone BBP and suggest possible strategies for preventing and treating human breast cancer.

  4. Vapor-Liquid Equilibrium Measurements and Modeling for Ternary System Water + Ethanol + 1-Butyl-3-methylimidazolium Acetate

    Institute of Scientific and Technical Information of China (English)

    D.ENG Dongshun; WANG Rufa; ZHANG Lianzhong; GE Yun; JI Jianbing

    2011-01-01

    Vapor-liquid equilibrium(VLE) data were measured for ternary system water + ethanol + 1-butyl-3methylimidazolium acetate([bmim][OAc]),in a relatively wide range of ionic liquid(IL) mass fractions up to 0.8.Six sets of complete T-x-y data were obtained,in which the mole fraction of ethanol on IL-free basis was fixed separately at 0.1,0.2,0.4,0.6,0.8,and approximate 0.98.The non-random-two-liquid(NRTL) and electrolyte non-random-two-liquid(eNRTL) equations were used for correlation,showing similar deviations.The ternary VLE was also modeled with the correlation from two data sets,with the mole fractions of ethanol on IL-free basis being 0.1 and approximate 0.98.The VLE data were also reproduced satisfactorily.With the eNRTL model,the root-mean-square deviation for temperature is 0.79K and that for vapor-phase mole fraction is 0.0094.The calculations are in good agreement with experimental data.The effect of the IL on the VLE behavior of the volatile components is also illustrated.

  5. Hexa-μ2-acetato-hexa-n-butyl-hexa-μ3-oxido-tin(IV) toluene monosolvate.

    Science.gov (United States)

    Reichelt, Martin; Reuter, Hans

    2013-01-01

    The title compound, [Sn6(C4H9)6(CH3COO)6O6]·C7H8, has one half-toluene mol-ecule and one half-organotin mol-ecule in the asymmetric unit. The latter is situated about an inversion centre and belongs to the class of hexa-meric monoorganooxo-tin carboxyl-ates with a hexa-gonal prismatic or 'drum-like' motif of the central tin-oxygen core. Two Sn3O3 rings in a flat-chair conformation are linked via six Sn-O bonds and six bridging acetate groups. All Sn atoms have approximate octa-hedral coordination geometry. The Sn-O bonds which are trans to the alkyl group are significantly shorter than the others. One butyl group is disordered over two different sites, with occupancies of 0.9:0.1. Very large atomic displacement parameters of the toluene mol-ecule indicate an unresolvable disorder about the twofold axis.

  6. Protective role of metabolism by intestinal microflora in butyl paraben-induced toxicity in HepG2 cell cultures.

    Science.gov (United States)

    Khanal, Tilak; Kim, Hyung Gyun; Jin, Sun Woo; Shim, Eol; Han, Hwa Jeong; Noh, Keumhan; Park, Sunkyoung; Lee, Dae Hun; Kang, Wonku; Yeo, Hee Kyung; Kim, Dong Hyun; Jeong, Tae Cheon; Jeong, Hye Gwang

    2012-09-03

    Parabens are alkyl esters of p-hydroxybenzoic acid (BA), including methyl paraben (MP), ethyl paraben, propyl paraben (PP), and butyl paraben (BP). In the present study, possible role of metabolism by fecalase in BP-induced cytotoxicity was investigated in HepG2 cell cultures. As an intestinal bacterial metabolic system, a human fecalase prepared from human fecal specimen was employed. Among the parabens tested, cytotoxicity of BP was most severe. BA, the de-esterified metabolite, did not induce cytotoxicity when compared to other parabens. When BP was incubated with fecalase, it rapidly disappeared, in association with reduced cytotoxicity in HepG2 cells. In addition, BP incubated with fecalase significantly caused an increase in Bcl-2 expression together with a decrease in Bax expression and cleaved caspase-3. Moreover, anti-apoptotic effect by the incubation of BP with fecalase was also confirmed by the TUNEL assay. Furthermore, BP induced a sustained activation of the phosphorylation of JNK only when it was treated alone. Meanwhile, BP-induced cell death was reversed by the pre-incubation of BP with either fecalase or SP600125. Taken together, the findings suggested that metabolism of BP by human fecalase might have protective effects against BP-induced toxicity in HepG2 cells.

  7. Benzyl butyl phthalate promotes adipogenesis in 3T3-L1 preadipocytes: A High Content Cellomics and metabolomic analysis.

    Science.gov (United States)

    Yin, Lei; Yu, Kevin Shengyang; Lu, Kun; Yu, Xiaozhong

    2016-04-01

    Benzyl butyl phthalate (BBP) has been known to induce developmental and reproductive toxicity. However, its association with dysregulation of adipogenesis has been poorly investigated. The present study aimed to examine the effect of BBP on the adipogenesis, and to elucidate the underlying mechanisms using the 3T3-L1 cells. The capacity of BBP to promote adipogenesis was evaluated by multiple staining approaches combined with a High Content Cellomics analysis. The dynamic changes of adipogenic regulatory genes and proteins were examined, and the metabolite profile was identified using GC/MC based metabolomic analysis. The High Content analysis showed BBP in contrast with Bisphenol A (BPA), a known environmental obesogen, increased lipid droplet accumulation in a similar dose-dependent manner. However, the size of the lipid droplets in BBP-treated cells was significantly larger than those in cells treated with BPA. BBP significantly induced mRNA expression of transcriptional factors C/EBPα and PPARγ, their downstream genes, and numerous adipogenic proteins in a dose and time-dependent manner. Furthermore, GC/MC metabolomic analysis revealed that BBP exposure perturbed the metabolic profiles that are associated with glyceroneogenesis and fatty acid synthesis. Altogether, our current study clearly demonstrates that BBP promoted the differentiation of 3T3-L1 through the activation of the adipogenic pathway and metabolic disturbance.

  8. Design of reactive distillation processes for the production of butyl acrylate:Impact of bio-based raw materials☆

    Institute of Scientific and Technical Information of China (English)

    Alexander Niesbach⁎; Natalia Fink; Philip Lutze; Andrzej Górak

    2015-01-01

    The chemical industry is nowadays predominantly using fossil raw materials, but the alternative use of bio-based resources is investigated to account for the foreseeable scarcity of fossil feedstocks. A main challenge of using bio-based feedstocks is the complexity of the impurity profile. For an economic production of bio-based chemicals, the use of intensified processes is inevitable and approaches are needed for the various process intensification techniques to identify their applicability to be used for the production of bio-based components. In the presented study, an approach is shown for the reactive distil ation (RD) technology to identify the most critical bio-based impurities and their impact on the reactive distillation process. The investigated case-study is the production of n-butyl acrylate from acrylic acid and n-butanol. Among al initially identified impurities, the key impurities, having the biggest impact on the product purity in the reactive distil ation process, are found. These impurities are then studied in more detail and an operating window depending on the impurity concentration is identified for the reactive distil ation column. Furthermore, an integrated design of upstream and downstream processes is facilitated, as the presented results can be used in the development of the fermentation processes for the produc-tion of the bio-based reactants by decreasing the concentration of the critical impurities.

  9. The efficient photocatalytic degradation of methyl tert-butyl ether under Pd/ZnO and visible light irradiation.

    Science.gov (United States)

    Seddigi, Zaki S; Ahmed, Saleh A; Bumajdad, Ali; Danish, Ekram Y; Shawky, Ahmed M; Gondal, Mohammed A; Soylak, Mustafa

    2015-01-01

    Methyl tert-butyl ether is a commonly used fuel oxygenate that is present in gasoline. It was introduced to eliminate the use of leaded gasoline and to improve the octane quality because it aids in the complete combustion of fuel by supplying oxygen during the combustion process. Over the past decade, the use of MTBE has increased tremendously worldwide. For obvious reasons relating to accidental spillage, MTBE started to appear as an environmental and human health threat because of its nonbiodegradable nature and carcinogenic potential, respectively. In this work, MTBE was degraded with the help of an advanced oxidation process through the use of zinc oxide as a photocatalyst in the presence of visible light. A mixture of 200 mg of zinc oxide in 350 mL of 50 ppm MTBE aqueous solution was irradiated with visible light for a given time. The complete degradation of MTBE was recorded, and approximately 99% photocatalytic degradation of 100 ppm MTBE solution was observed. Additionally, the photoactivity of 1% Pd-doped ZnO was tested under similar conditions to understand the effect of Pd doping on ZnO. Our results obtained under visible light irradiation are very promising, and they could be further explored for the degradation of several nondegradable environmental pollutants.

  10. Subcellular distribution and uptake mechanism of di-n-butyl phthalate in roots of pumpkin (Cucurbita moschata) seedlings.

    Science.gov (United States)

    Lin, Qingqi; Yang, Xiuhong; Huang, Xiongfei; Wang, Shizhong; Chao, Yuanqing; Qiu, Rongliang

    2016-01-01

    Phthalate acid esters (PAEs) are of particular concern due to their potential environmental risk to human and nonhuman organisms. Although uptake of PAEs by plants has been reported by several researchers, information about the intracellular distribution and uptake mechanisms of PAEs is still lacking. In this study, a series of hydroponic experiments using intact pumpkin (Cucurbita moschata) seedlings was conducted to investigate how di-n-butyl phthalate (DnBP), one of the most frequently identified PAEs in the environment, enters and is distributed in roots. DnBP was transported into subcellular tissues rapidly in the initial uptake period (<12 h). More than 80% of DnBP was detected in the cell walls and organelles, which suggests that DnBP is primarily accumulated in these two fractions due to their high affinity to DnBP. The kinetics of DnBP uptake were fitted well with the Michaelis-Menten equation, suggesting that a carrier-mediated process was involved. The application of 2,4-dinitrophenol and sodium vanadate reduced the uptake of DnBP by 37 and 26%, respectively, while aquaporin inhibitors, silver and glycerol, had no effect on DnBP uptake. These data demonstrated that the uptake of DnBP included a carrier-mediated and energy-dependent process without the participation of aquaporins.

  11. DFT Studies on the Isomerization of Butene Double Bond Catalyzed by 1-Butyl-3-methyl-imidazolium in Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    LI Ying-Xia; PU Min; CHEN Biao-Hua; LI Hui-Ying; LIU Kun-Hui; WANG Wen-Xing

    2005-01-01

    The geometries of reactant, product and transition state of the title reaction have been optimized by using density functional theory (DFT) at the B3LYP/6-31G(d,p) and B3LYP/6- 311++G(d,p) levels.The variations of the bond parameters in the course of reaction were analyzed.The zero point energy corrections were performed by vibrational analysis.The equilibrium states and the transition state were verified according to the number of virtue frequency of geometry.The intrinsic reaction coordinates (IRC) were calculated from the transition state.The calculated results show that the double bond rearrangement of butene catalyzed by 1-butyl-3-methyl-imidazolium cation is a one-step reaction.The forward energy barrier of isomerization from 1-butene to 2- butene is about 193 kJmol-1 and the reverse energy barrier about 209 kJmol-1 at the B3LYP/6- 31G(d,p) level, which means that the reaction is easy to proceed at or above room temperature.

  12. Continuous on-line determination of methyl tert-butyl ether in water samples using ion mobility spectrometry.

    Science.gov (United States)

    Borsdorf, H; Rämmler, A

    2005-04-22

    A rapid analytical procedure for the on-line determination of methyl tert-butyl ether (MTBE) in water samples was developed. A new membrane extraction unit was used to extract the MTBE from water samples. The concentration of MTBE was determined using ion mobility spectrometry with 63Ni ionization and corona discharge ionization without chromatographic separation. Both ionization methods permit the sensitive determination of MTBE. A detection limit of 100 microg/L was established for the on-line procedure. Neither the inorganic compounds, humic substances nor gasoline were found to exert a significant influence on the peak intensity of the MTBE. The screening procedure can be used for concentrations of monoaromatic compounds (benzene, toluene, xylene) up to 600 microg/L. No sample preparation is required and the analysis results are available within 5 min. In order to determine concentrations between 10 microg/L and 100 microg/L, a discontinuous procedure was developed on the basis of the same experimental set-up.

  13. Vibrio fischeri and Escherichia coli adhesion tendencies towards photolithographically modified nanosmooth poly (tert-butyl methacrylate polymer surfaces

    Directory of Open Access Journals (Sweden)

    Elena P Ivanova

    2008-09-01

    Full Text Available Elena P Ivanova1, Natasa Mitik-Dineva1, Radu C Mocanasu1, Sarah Murphy1, James Wang2, Grant van Riessen3, Russell J Crawford11Faculty Life and Social Sciences; 2IRIS, Swinburne University of Technology, Hawthorn, Victoria, Australia; 3Centre for Materials and Surface Science, La Trobe University, Melbourne, Victoria, AustraliaAbstract: This study reports the adhesion behavior of two bacterial species, Vibrio fischeri and Escherichia coli, to the photoresistant poly(tert-butyl methacrylate (P(tBMA polymer surface. The data has demonstrated that ultraviolet irradiation of P(tBMA was able to provide control over bacterial adhesion tendencies. Following photolithography, several of the surface characteristics of P(tBMA were found to be altered. Atomic force microscopy analysis indicated that photolithographically modified P(tBMA (henceforth termed ‘modified polymer’ appeared as a ‘nanosmooth’ surface with an average surface roughness of 1.6 nm. Although confocal laser scanning microscopy and scanning electron microscopy analysis clearly demonstrated that V. fischeri and E. coli presented largely different patterns of attachment in order to adhere to the same surfaces, both species exhibited a greater adhesion propensity towards the ‘nanosmooth’ surface. The adhesion of both species to the modified polymer surface appeared to be facilitated by an elevated production of extracellular polymeric substances when in contact with the substrate.Keywords: poly(tert-butylmethacrylate polymeric surfaces, surface nanotopography, bacterial attachment, extracellular polymeric substances

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

    Directory of Open Access Journals (Sweden)

    Dalin Hu

    2016-02-01

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

  15. Investigation of extraction fraction in confined impinging jet reactors for tri-butyl-phosphate extracting butyric acid process☆

    Institute of Scientific and Technical Information of China (English)

    Zhengming Gao; Manting Zhao; Yun Yu; Zhipeng Li; Jing Han

    2016-01-01

    The extraction fraction E and overall volumetric mass transfer coefficient kLa of TBP extracting butyric acid pro-cess in confined impinging jet reactors (CIJR) with two jets were investigated. The main variables tested were the concentration of tri-butyl-phosphate (TBP) and butyric acid, the impinging velocity V, the impinging velocity ratio of two phases Vorg/Vaq, the nozzle inner diameter di and the distance L between the jet axes and the top wall of the impinging chamber. The results showed that E and kLa increase with an increase of the impinging ve-locity V, the concentration of TBP Corg, and the impinging velocity ratio Vorg/Vaq. However, E and kLa decrease with an increase of the inner diameter di from 1 to 2 mm, the concentration of butyric acid Caq from 0.5%(v/v) to 2%(v/v). The factor L ranging from 3 to 11 mm has a negligible effect on E and kLa. A correlation on these variables and kLa was proposed based on the experimental data. These results indicated good mass transfer performance of CIJR in the extraction operation.

  16. Computational Study of Molecular Structure and Self-Association of Tri-n-butyl Phosphates in n-Dodecane

    Energy Technology Data Exchange (ETDEWEB)

    Vo, Quynh N.; Hawkins, Cory; Dang, Liem X.; Nilsson, Mikael; Nguyen, Hung D.

    2015-01-29

    Tri-n-butyl phosphate is an important extractant used in solvent extraction process for the recovery of uranium and plutonium from spent nuclear fuel. To understand the fundamental molecular level behavior of extracting agents in solution, an atomistic parameterization study was carried out using the AMBER force field to model TBP molecule and n-dodecane molecule, a commonly used organic solvent, for molecular dynamics simulations. For validation of the optimized force field, various thermophysical properties of pure TBP and pure n-dodecane in the bulk liquid phase such as mass density, dipole moment, self-diffusion coefficient and heat of vaporization were calculated and compared favorably with experimental values. The molecular structure of TBPs in n-dodecane at various TBP concentrations was examined based on radial distribution functions and 2D potential mean force, which was used as criteria for identifying TBP aggregates. The dimerization constant of TBP in n-dodecane was also obtained and matches the experimental value. The U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences funded the work performed by LXD.

  17. Enhanced ozonation degradation of di-n-butyl phthalate by zero-valent zinc in aqueous solution: performance and mechanism.

    Science.gov (United States)

    Wen, Gang; Wang, Sheng-Jun; Ma, Jun; Huang, Ting-Lin; Liu, Zheng-Qian; Zhao, Lei; Su, Jun-Feng

    2014-01-30

    Enhanced ozonation degradation of di-n-butyl phthalate (DBP) by zero-valent zinc (ZVZ) has been investigated using a semi-continuous reactor in aqueous solution. The results indicated that the combination of ozone (O3) and ZVZ showed an obvious synergetic effect, i.e. an improvement of 54.8% on DBP degradation was obtained by the O3/ZVZ process after 10min reaction compared to the cumulative effect of O3 alone and O2/ZVZ. The degradation efficiency of DBP increased gradually with the increase of ZVZ dosage, enhanced as solution pH increasing from 2.0 to 10.0, and more amount of DBP was degraded with the initial concentration of DBP arising from 0.5 to 2.0mgL(-1). Recycling use of ZVZ resulted in the enhancement of DBP degradation, because the newly formed zinc oxide took part in the reaction. The mechanism investigation demonstrated that the enhancement effect was attributed to the introduction of ZVZ, which could promote the utilization of O3, enhance the formation of superoxide radical by reducing O2 via one-electron transfer, accelerate the production of hydrogen peroxide and the generation of hydroxyl radical. Additionally, the newly formed zinc oxide on ZVZ surface also contributed to the enhancement of DBP degradation in the recycling use of ZVZ. Most importantly, the O3/ZVZ process was also effective in enhanced ozonation degradation of DBP under the background of actual waters.

  18. Application of the Ozonation Pre-treatment for Biodegradation of Aqueous Solutions of Methyltert-Butyl Ether

    Directory of Open Access Journals (Sweden)

    M. Sadeghi

    2005-01-01

    Full Text Available The effectiveness of ozone treatment for improving the biodegradability of recalcitrant pollutants has been proved by investigating the ozonation reaction of Methyl tert-butyl ether (MTBE a bioresistant gasoline oxygenate. Laboratory scale experiments have been carried out, at room temperature, by bubbling, for 120 min, ozonated air (3.4 ppm min-1 into 3 liter of an alkaline (pH=11.5 aqueous solution (100 mg L-1 of MTBE. The experimental results indicated that during the ozonation, complete MTBE degradation occurs in 100 min and after this time, ozone consumption goes on very slowly. At the end of the ozonation, after 100 min, the initial value of COD (256 mg O2 L-1 is 98 and correspond to a relative removal of about 62%.As for MTBE solution biodegradability expressed as (BOD5/(COD ratio, during the first 90 min its value regularly increases from lowest (0.01 up to a maximum of 0.68 that corresponds to an ozone consumption of 1.25 mg per each mg of COD initially present in the solution.The experimental results for determining the rate of MTBE removal due to stripping showed that about 14% of MTBE strips out after an hour of sparging with oxygen gas. The fraction of MTBE oxidized and/or striped increases to about 28% (in pH=7 and 70% (in pH=11.5 with ozonation over the same time period.

  19. Structure and dynamics of 1-butyl-3-methylimidazolium hexafluorophosphate phases on silica and laponite clay: from liquid to solid behavior.

    Science.gov (United States)

    Castillo, M Rosa; Fraile, José M; Mayoral, José A

    2012-08-07

    Solid-state NMR experiments show that the behavior of supported 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid phases depends on the type of support and the phase thickness. A mobile nearly liquid phase is obtained on silica, on the basis of the line widths of the bands in (1)H, (31)P, and (13)C spectra. However, the mobility is somehow restricted, as shown by the possibility of using the cross-polarization technique, although with slow dynamics. On laponite clay, a layered material with a negatively charged surface, a truly solid phase is obtained at low coverage, whereas the increase in ionic liquid loading leads to a second liquid phase, as shown by the presence of two contributions with very different line widths. These two phases seem to coexist without exchange in the NMR time frame. Heteronuclear correlation experiments evidence different relative dispositions of the imidazolium-surface-PF(6) system, with only aromatic protons involved in all the interactions on silica but participation of the benzylic groups (N-CH(3) and/or N-CH(2)) in the case of laponite clay.

  20. Uranium extraction from TRISO-coated fuel particles using supercritical CO2 containing tri-n-butyl phosphate.

    Science.gov (United States)

    Zhu, Liyang; Duan, Wuhua; Xu, Jingming; Zhu, Yongjun

    2012-11-30

    High-temperature gas-cooled reactors (HTGRs) are advanced nuclear systems that will receive heavy use in the future. It is important to develop spent nuclear fuel reprocessing technologies for HTGR. A new method for recovering uranium from tristructural-isotropic (TRISO-) coated fuel particles with supercritical CO(2) containing tri-n-butyl phosphate (TBP) as a complexing agent was investigated. TRISO-coated fuel particles from HTGR fuel elements were first crushed to expose UO(2) pellet fuel kernels. The crushed TRISO-coated fuel particles were then treated under O(2) stream at 750°C, resulting in a mixture of U(3)O(8) powder and SiC shells. The conversion of U(3)O(8) into solid uranyl nitrate by its reaction with liquid N(2)O(4) in the presence of a small amount of water was carried out. Complete conversion was achieved after 60 min of reaction at 80°C, whereas the SiC shells were not converted by N(2)O(4). Uranyl nitrate in the converted mixture was extracted with supercritical CO(2) containing TBP. The cumulative extraction efficiency was above 98% after 20 min of online extraction at 50°C and 25 MPa, whereas the SiC shells were not extracted by TBP. The results suggest an attractive strategy for reprocessing spent nuclear fuel from HTGR to minimize the generation of secondary radioactive waste.

  1. Copolymers of N-cyclohexylacrylamide and n-butyl acrylate: synthesis, characterization, monomer reactivity ratios and mean sequence length

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available Copolymerization of N-cyclohexylacrylamide (NCHA and n-butyl acrylate (BA was carried out in dimethylformamide at 55±1°C using azobisisobutyronitrile as a free radical initiator. The copolymers were characterized by 1H-NMR spectroscopy and the copolymer compositions were determined by 1H-NMR analysis. The reactivity ratios of the monomers were determined by both linear and non-linear methods. The reactivity ratios of monomers determined using linear methods like Fineman-Ross (r1 = 0.37 and r2 = 1.77 , Kelen-Tudos (r1 = 0.38 and r2 = 1.77, ext. Kelen-Tudos (r1 = 0.37 and r2 = 1.75 Yezrieler-Brokhina-Roskin (r1 = 0.37 and r2 = 1.77 and non-linear methods like Tidwell-Mortimer (r1 = 0.37 and r2 = 1.76, ProCop (r1 = 0.36 and r2 = 1.82. The Q and e values for NCHA are 0.67 and 0.68 respectively. Mean sequence lengths of copolymers are estimated from r1 and r2 values. It shows that the BA units increases in a linear fashion in the polymer chain as the concentration of BA increases in the monomer feed.

  2. Growth and characterization of butyl 4-hydroxybenzoate single crystal by vertical Bridgman technique for third order nonlinear optical applications

    Science.gov (United States)

    Arivazhagan, T.; Siva Bala Solanki, S.; Rajesh, Narayana Perumal

    2017-02-01

    The butyl 4-hydroxybenzoate single crystal has been grown by vertical Bridgman technique using single wall ampoule. The cell parameters of the grown crystal are verified by single crystal X-ray diffraction analysis. The functional groups of the grown crystal were identified by Fourier transform infrared analysis. The melting, decomposition and crystallization point of the compound are determined by thermo gravimetric analysis and differential scanning calorimetric analysis. The mechanical properties of the grown crystal has been analyzed by Vickers microhardness method. The optical behavior of the grown crystal has been observed by UV-vis-NIR transmission spectroscopic analysis which shows that the lower cut-off wavelength lying at 293 nm and found that the energy band gap value is 4.05 eV. The blue light emission of the crystal was identified by photoluminescence studies. The positive third order nonlinear optical parameters like nonlinear refractive index (n2), nonlinear absorption co-efficient (β) and third order nonlinear susceptibility (χ3) of the grown crystal was calculated by Z-scan studies. The positive sign of nonlinear refractive index (n2) indicates that the crystal exhibits self focusing optical nonlinearity. The crystal exhibits good optical power limiting behavior.

  3. The influence of tertiary butyl hydrazine as a co-reactant on the atomic layer deposition of silver

    Science.gov (United States)

    Golrokhi, Zahra; Marshall, Paul A.; Romani, Simon; Rushworth, Simon; Chalker, Paul R.; Potter, Richard J.

    2017-03-01

    Ultra-thin conformal silver films are the focus of development for applications such as anti-microbial surfaces, optical components and electronic devices. In this study, metallic silver films have been deposited using direct liquid injection thermal atomic layer deposition (ALD) using (hfac)Ag(1,5-COD) ((hexafluoroacetylacetonato)silver(I)(1,5-cyclooctadiene)) as the metal source and tertiary butyl hydrazine (TBH) as a co-reactant. The process provides a 23 °C wide 'self-limiting' ALD temperature window between 105 and 128 °C, which is significantly wider than is achievable using alcohol as a co-reactant. A mass deposition rate of ∼20 ng/cm2/cycle (∼0.18 Å/cycle) is observed under self-limiting growth conditions. The resulting films are crystalline metallic silver with a near planar film-like morphology which are electrically conductive. By extending the temperature range of the ALD window by the use of TBH as a co-reactant, it is envisaged that the process will be exploitable in a range of new low temperature applications.

  4. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Ghim, Deoukchen; Kim, Jung Hyeun [University of Seoul, Seoul (Korea, Republic of)

    2016-02-15

    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T{sub g} of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  5. Molecular dynamics and partitioning of di-tert-butyl nitroxide in stratum corneum membranes: effect of terpenes.

    Science.gov (United States)

    Camargos, Heverton Silva; Silva, Adolfo Henrique Moraes; Anjos, Jorge Luiz Vieira; Alonso, Antonio

    2010-05-01

    In this work, we have used electron paramagnetic resonance (EPR) spectroscopy of the small spin label di-tert-butyl nitroxide (DTBN), which partitions the aqueous and hydrocarbon phases, to study the interaction of the terpenes alpha-terpineol, 1,8-cineole, L(-)-carvone and (+)-limonene with the uppermost skin layer, the stratum corneum, and the membrane models of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). The EPR spectra indicated that the terpenes increase both the partition coefficient and the rotational correlation time of the spin labels in the stratum corneum membranes, whereas similar effects were observed in the DMPC and DPPC bilayers only at temperatures below the liquid-crystalline phase. The EPR parameter associated to probe polarity inside the membranes showed thermotropically induced changes, suggesting relocations of spin probe, which were dependent on the membrane phases. While the DMPC and DPPC bilayers showed abrupt changes in the partitioning and rotational correlation time parameters in the phase transitions, the SC membranes were characterized by slight changes in the total range of measured temperatures, presenting the greatest changes or membranes reorganizations in the temperature range of approximately 50 to approximately 74 degrees C. The results suggest that terpenes act as spacers, weakening the hydrogen-bonded network at the polar interface and thus fluidizing the stratum corneum lipids.

  6. Dielectric relaxation and solvation dynamics in a prototypical ionic liquid + dipolar protic liquid mixture: 1-butyl-3-methylimidazolium tetrafluoroborate + water.

    Science.gov (United States)

    Zhang, Xin-Xing; Liang, Min; Hunger, Johannes; Buchner, Richard; Maroncelli, Mark

    2013-12-12

    Dielectric and solvation data on mixtures of 1-butyl-3-methylimidazilium tetrafluoroborate ([Im41][BF4]) + water are reported and used to examine the utility of dielectric solvation models. Dielectric permittivity and loss spectra (25 °C) were recorded over the frequency range 200 MHz to 89 GHz at 17 compositions and fit to a 4-Debye form. Dynamic Stokes shift measurements on the solute coumarin 153 (C153), made by combining fluorescence upconversion (80 fs resolution) and time-correlated single photon counting data (20 ns range), were used to determine the solvation response at 7 compositions (20.5 °C). All properties measured here were found to depend upon mixture composition in a simple continuous manner, especially when viewed in terms of volume fraction. Solvation response functions predicted by a simple dielectric continuum model are similar to but ∼7-fold faster than the spectral response functions measured with C153. The solvation data are in better agreement with the recently published predictions of a semimolecular model of Biswas and co-workers [J. Phys. Chem. B 2011, 115, 4011], but these latter predictions are systematically slow by a factor of ∼3.

  7. Co3(RL)2(hfac)6 ladder complex of 5-[4-(N-tert-butyl-N-aminoxyl)phenyl]pyrimidine.

    Science.gov (United States)

    Field, Lora M; Morón, M Carmen; Lahti, Paul M; Palacio, Fernando; Paduan-Filho, Armando; Oliveira, Nei F

    2006-03-20

    5-[4-(N-tert-butyl-N-aminoxyl)phenyl]pyridimine (4NITPhPyrim = RL) forms a 1-D ladder polymer complex with Co(hfac)2 of stoichiometry Co3(RL)2(hfac)6, having antiparallel [Co(II)RL]n linear chains (rails) that are cross-linked by Pyrim-Co(hfac)2-Pyrim rungs. The magnetic behavior above 100 K is consistent with contributions from one high-spin Co(II) ion (the cross-link, S = 3/2) plus two Co-ON units with strongly antiferromagnetic (AFM) metal-radical exchange (each S = 1). The chiT data show an AFM downturn as the temperature drops. Assuming weak exchange along chain portions of the polymer due to poor spin polarization across the phenyl-pyrimidine bond in RL, a linear three-spin (S = 1, 3/2, and 1) fit to the T > 18 K data yields an AFM cross-linker (rung) effective exchange of J(CL)/k = (-)5.3 K = (-)3.7 cm(-)(1). Superexchange (sigma-orbital overlap) is a likely mechanism for the effective AFM exchange between CoON and Co spin sites in the three-spin groupings.

  8. The plasticizer butyl benzyl phthalate induces genomic changes in rat mammary gland after neonatal/prepubertal exposure

    Directory of Open Access Journals (Sweden)

    Lamartiniere Coral A

    2007-12-01

    Full Text Available Abstract Background Phthalate esters like n-butyl benzyl phthalate (BBP are widely used plasticizers. BBP has shown endocrine-disrupting properties, thus having a potential effect on hormone-sensitive tissues. The aim of this study is to determine the effect of neonatal/prepubertal exposure (post-natal days 2–20 to BBP on maturation parameters and on the morphology, proliferative index and genomic signature of the rat mammary gland at different ages of development (21, 35, 50 and 100 days. Results Here we show that exposure to BBP increased the uterine weight/body weight ratio at 21 days and decreased the body weight at time of vaginal opening. BBP did not induce significant changes on the morphology of the mammary gland, but increased proliferative index in terminal end buds at 35 days and in lobules 1 at several ages. Moreover, BBP had an effect on the genomic profile of the mammary gland mainly at the end of the exposure (21 days, becoming less prominent thereafter. By this age a significant number of genes related to proliferation and differentiation, communication and signal transduction were up-regulated in the glands of the exposed animals. Conclusion These results suggest that BBP has an effect in the gene expression profile of the mammary gland.

  9. Study of an aquifer contaminated by ethyl tert-butyl ether (ETBE): site characterization and on-site bioremediation.

    Science.gov (United States)

    Fayolle-Guichard, Françoise; Durand, Jonathan; Cheucle, Mathilde; Rosell, Mònica; Michelland, Rory Julien; Tracol, Jean-Philippe; Le Roux, Françoise; Grundman, Geneviève; Atteia, Olivier; Richnow, Hans H; Dumestre, Alain; Benoit, Yves

    2012-01-30

    Ethyl tert-butyl ether (ETBE) was detected at high concentration (300mgL(-1)) in the groundwater below a gas-station. No significant carbon neither hydrogen isotopic fractionation of ETBE was detected along the plume. ETBE and BTEX biodegradation capacities of the indigenous microflora Pz1-ETBE and of a culture (MC-IFP) composed of Rhodococcus wratislaviensis IFP 2016, Rhodococcus aetherivorans IFP 2017 and Aquincola tertiaricarbonis IFP 2003 showed that ETBE and BTEX degradation rates were in the same range (ETBE: 0.91 and 0.83 mg L(-1)h(-1) and BTEX: 0.64 and 0.82 mg L(-1)h(-1), respectively) but tert-butanol (TBA) accumulated transiently at a high level using Pz1-ETBE (74 mg L(-1)). An on-site pilot plant (2m(3)) filled with polluted groundwater and inoculated by MC-IFP, successfully degraded four successive additions of ETBE and gasoline. However, an insignificant ETBE isotopic fractionation was also accompanying this decrease which suggested the involvement of low fractionating-strains using EthB enzymes, but required of additional proofs. The ethB gene encoding a cytochrome P450 involved in ETBE biodegradation (present in R. aetherivorans IFP 2017) was monitored by quantitative real-time polymerase chain reaction (q-PCR) on DNA extracted from water sampled in the pilot plant which yield up to 5×10(6) copies of ethB gene per L(-1).

  10. Aldh2 knockout mice were more sensitive to DNA damage in leukocytes due to ethyl tertiary butyl ether exposure.

    Science.gov (United States)

    Weng, Zuquan; Suda, Megumi; Ohtani, Katsumi; Mei, Nan; Kawamoto, Toshihiro; Nakajima, Tamie; Wang, Rui-Sheng

    2011-01-01

    To clarify the genotoxicity of ethyl tertiary butyl ether (ETBE), a gasoline additive, male and female C57BL/6 mice of Aldh2+/+ and Aldh2-/- genotypes, aged 8 wk, were exposed to 0, 500, 1,750, or 5,000 ppm ETBE for 6 h/day, 5 d per week for 13 wk. DNA damage in leukocytes was measured by the alkaline comet assay and expressed quantitatively as Tail Intensity (TI). For male mice, TI was significantly higher in all three groups exposed to ETBE than in those without exposure within Aldh2-/- mice, whereas within Aldh2+/+ mice, TI increased only in those exposed to 5,000 ppm of ETBE as compared with mice without exposure. For female mice, a significant increase in TI values was observed in the group exposed to 5,000 ppm of ETBE as compared with those without exposure within Aldh2-/- mice; TI in Aldh2-/- mice exposed to 1,750 and 5,000 ppm was significantly higher than in Aldh2+/+ mice without exposure. TI did not significantly increase in any of the groups exposed to ETBE within female Aldh2+/+ mice. Based on the results we suggest that Aldh2-/- mice are more sensitive to DNA damage caused by ETBE than Aldh2+/+ mice and that males seem more susceptible to this effect than females.

  11. Induction of cell proliferation in the rat liver by the short-term administration of ethyl tertiary-butyl ether.

    Science.gov (United States)

    Kakehashi, Anna; Hagiwara, Akihiro; Imai, Norio; Wei, Min; Fukushima, Shoji; Wanibuchi, Hideki

    2015-01-01

    In the present study, in continuation of our previous experiment in order to investigate the mode of action (MOA) of ethyl tertiary-butyl ether (ETBE) hepatotumorigenicity in rats, we aimed to examine alterations in cell proliferation, that are induced by short-term administration of ETBE. F344 rats were administered ETBE at doses of 0, and 1,000 mg/kg body weight twice a day by gavage for 3, 10, 17 and 28 days. It was found that the previously observed significant increase of P450 total content and hydroxyl radical levels after 7 days of ETBE administration, and 8-OHdG formation at day 14, accompanied by accumulation of CYP2B1/2B2, CYP3A1/3A2, CYP2C6, CYP2E1 and CYP1A1 and downregulation of DNA oxoguanine glycosylase 1, was preceded by induction of cell proliferation at day 3. Furthermore, we observed an increase in regenerative cell proliferation as a result of ETBE treatment at day 28, followed by induction of cell cycle arrest and apoptosis by day 14. These results indicated that short-term administration of ETBE led to a significant early increase in cell proliferation activity associated with induction of oxidative stress, and to a regenerative cell proliferation as an adaptive response, which could contribute to the hepatotumorigenicity of ETBE in rats.

  12. 2D-Cell Experiment on Methyl Tert-Butyl Ether Transport in Saturated Zone of Groundwater

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As an additive of gasoline, methyl tert-butyl ether (MTBE) has a higher solubility in water, which is about 20 times as high as that of benzene. This characteristic results in MTBE dissolving out of the gasoline into the soil and groundwater. Due to relative unique physicochemical behavior of MTBE it would be an ideal candidate for use in environmental forensic investigations. In order to study the transport and distribution of MTBE in saturated zone of ground water, a two-dimensional experimental cell was setup to simulate the real environment of the groundwater flow.The effects of soil and groundwater flow velocity on the MTBE transport were investigated. The results show that the mobile distance of MTBE in vertical direction was smaller than that in horizontal direction paralleling with the groundwater flow. Because the main dynamics of groundwater flow direction was convection and dispersion, the movement of MTBE is also diffusion in the vertical direction. In addition, the transport of MTBE was more quick in high permeability porous media, and the increase of groundwater flow velocity can accelerate the MTBE plume development, but the irregularity and randomness of the plume are enhanced synchronously. These research results can give some helps for the investigation of MTBE movement in the groundwater, also can make some references for other petroleum contamination behavior.

  13. Experimental and theoretical studies on new 7-(3,6-di-tert-butyl-9H-carbazol-9-yl)-10-alkyl-10H-phenothiazine-3-carbaldehydes

    Science.gov (United States)

    Stalindurai, Kesavan; Gokula Krishnan, Kannan; Nagarajan, Erumaipatty Rajagounder; Ramalingan, Chennan

    2017-02-01

    Synthesis of fused heterocyclic aldehydes with carbazole (CZ) structural motif linked at C-7 position on phenothiazines (PTZ), 7-(3,6-di-tert-butyl-9H-carbazol-9-yl)-10-butyl-10H-phenothiazine-3-carbaldehyde (1) and 7-(3,6-di-tert-butyl-9H-carbazol-9-yl)-10-hexyl-10H-phenothiazine-3-carbaldehyde (2) has been accomplished and are characterized through experimental and computational techniques. The optimized structure with their bonding aspects and vibrational frequencies of the same have been examined utilizing DFT-B3LYP technique with a basis set 6-311++G(d,p). In the optimized structures of 1 and 2, the bond lengths and bond angles are in accord with their corresponding reported analogous. The vibrational frequencies resulted from experimental as well as theoretical are in well accord with each other. Further, the results of polarizabilities, first order hyperpolarizabilities and dipole moment of 1 and 2 imply that these could be utilized for the preparation of NLO crystals which might generate second order harmonic waves.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-02-01

    Chemical structure and physical properties of materials, such as polymers, can be altered as aging progresses, which may result in a material that is ineffective for its envisioned intent. Butyl rubber formulations, starting material, and additives were aged under thermal-oxidative conditions for up to 413 total days at up to 124 ÀC. Samples included: two formulations developed at Kansas City Plant (KCP) (#6 and #10), one commercially available formulation (#21), Laxness bromobutyl 2030 starting material, and two additives (polyethylene AC-617 and Vanax MBM). The low-molecular weight volatile thermal-oxidative degradation products that collected in the headspace over the samples were preconcentrated, separated, and detected using cryofocusing gas chromatography mass spectrometry (cryo-GC/MS). The majority of identified degradation species were alkanes, alkenes, alcohols, ketones, and aldehydes. Observations for Butyl #10 aged in an oxygen-18 enriched atmosphere (18O2) were used to verify when the source of oxygen in the applicable degradation products was from the gaseous environment rather than the polymeric mixture. For comparison purposes, Butyl #10 was also aged under non-oxidative thermal conditions using an argon atmosphere.

  15. Isolation and structural elucidation of 4-(beta-D-glucopyranosyldisulfanyl)butyl glucosinolate from leaves of rocket salad (Eruca sativa L.) and its antioxidative activity.

    Science.gov (United States)

    Kim, Sun-Ju; Jin, Shigeki; Ishii, Gensho

    2004-12-01

    A structurally unique glucosinolate (GSL) was identified to be 4-(beta-D-glucopyranosyldisulfanyl)butyl GSL in rocket leaves. The positive-ion electrospray ionization mass spectrometry (ESI-MS) data indicated that the new GSL had a molecular weight of 521 (m/z 522, [M+H](+), as desulfo-GSL). The molecular formula of the substance was determined to be C(17)H(32)O(11)NS(3) (m/z 522.1143, [M+H](+)) based on its positive-ion high-resolution fast atom bombardment mass spectrometry (HR-FAB-MS) data. For the further confirmation, desulfated GSL of 4-(beta-D-glucopyranosyldisulfanyl)butyl GSL was prepared by commercial 1-thio-beta-D-glucose and dimeric 4-mercaptobutyl desulfo-GSL, which was also isolated from rocket leaves, and its chemical structure was then confirmed by MS data and nuclear magnetic resonance (NMR) spectroscopy. In addition, the antioxidative activity of 4-(beta-D-glucopyranosyldisulfanyl)butyl desulfo-GSL was measured by means of chemiluminescence (CL) for evaluating the functional properties. The antioxidative activity (2.089 unit/g) was relatively higher than that of dimeric 4-mercaptobutyl desulfo-GSL (1.227).

  16. Photocatalytic Degradation of Di-n-Butyl Phthalate by N-Doped Ti/13X/MCM-41 Molecular Sieve.

    Science.gov (United States)

    Tao, Hong; Nguyen, Nhat-Thien; Heil, Xiao-Hui; Liang, Xiao; Chang, Chang-Tang

    2015-07-01

    Di-n-butyl phthalate (DBP) is a type of phthalate ester, and has been classified as an environmental endocrine disruptor. It causes serious harm to the environment and humans and it is found widely in air, waste water, rivers and soil. In recent years, an increasing number of studies examined the removal of DBP. Photocatalytic degradation has been of particular interest because of its efficient and thorough advantages and is the focus of this study. Here we use a composite material of N-Ti/13X/MCM-41, synthesized, using 13X and tetraethyl orthosilicate as raw material, CTAB as structural template, tetrabutyl titanate and urea under hydrothermal conditions. The optimized experimental conditions, such as, Si/Al (molar ratio), pH value, crystallization time, calcination temperature and N/Ti (molar ratio), were tested using photodegradation experiments of DBP. The samples were characterized by XRD, TEM, FT-IR, N2 adsorption-desorption. Experimental results reveal the surface area of the N-Ti/13X/MCM-41 to be 664 m2 g(-1) and the average pore sizes to be 2.79 nm. TEM micrographs showed the N-Ti/13X/MCM-41 consists of aggregates of spherical particles, similar to the shapes associated with standard MCM-41 synthesized under basic conditions. Photocatalytic degradation experimental results revealed that optimal synthesis of the composite material occurs when Si/Al = 15, pH = 9.0, crystallization time is 48 hours, calcination temperature is 350 °C and the N/Ti ratios is 2.0. Under such conditions, the degradation efficiency of DBP more was found to be more than 90%.

  17. Neutral lipid biosynthesis in engineered Escherichia coli: jojoba oil-like wax esters and fatty acid butyl esters.

    Science.gov (United States)

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-02-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

  18. Prevalence of gastric varices and results of sclerotherapy with N-butyl 2 cyanoacrylate for controlling acute gastric variceal bleeding

    Institute of Scientific and Technical Information of China (English)

    Khalid Mumtaz; Shahid Majid; Hasnain A Shah; Kashif Hameed; Ashfaq Ahmed; Saeed Hamid; Wasim Jafri

    2007-01-01

    AIM: To study the prevalence, predictors and control of bleeding following N-butyl 2 cyanoacrylate (NBC)sclerotherapy of gastric varix (GV).METHODS: We analyzed case records of 1436 patients with portal hypertension, who underwent endoscopy during the past five years for variceal screening or upper gastrointestinal (GI) bleeding. Fifty patients with bleeding GV underwent sclerotherapy with a mean of 2 mL NBC for control of bleeding. Outcome parameters were primary hemostasis (bleeding control within the first 48 h), recurrent bleeding (after 48 h of esophagogastro-duodenoscopy) and in-hospital mortality were analyzed.RESULTS: The prevalence of GV in patients with portal hypertension was 15% (220/1436) and the incidence of bleeding was 22.7% (50/220). Out of the 50 bleeding GV patients, isolated gastric varices (IGV-Ⅰ) were seen in 22 (44%), gastro-oesophageal varices (GOV) on lesser curvature (GOV-Ⅰ ) in 16 (32%), and GOV on greater curvature (GOV-Ⅱ) in 15 (30%). IGV- Ⅰ was seen in 44% (22/50) patients who had bleeding as compared to 23% (39/170) who did not have bleeding (P <0.003). Primary hemostasis was achieved with NBC in all patients. Re-bleeding occurred in 7 (14%) patients after 48 h of initial sclerotherapy. Secondary hemostasis was achieved with repeat NBC sclerotherapy in 4/7(57%). Three patients died after repeat sclerotherapy,one during transjugular intrahepatic portosysternic stem shunt (TIPSS), one during surgery and one due to uncontrolled bleeding. Treatment failure-related mortality rate was 6% (3/50).CONCLUSION: GV can be seen in 15% of patients with portal hypertension and the incidence of bleeding is 22.7%. NBC is highly effective in controlling GV bleeding.In hospital mortality of patients with bleeding GV is 6%.

  19. Di(n-butyl phthalate has no effect on the rat prepubertal testis despite its estrogenic activity in vitro

    Directory of Open Access Journals (Sweden)

    Jerzy Długoński

    2012-01-01

    Full Text Available The aim of this study was to assess the impact of di(n-butyl phthalate (DBP on the rat’s prepubertal testis. Male Wistar rats were given daily subcutaneous injections with DBP (20 or 200 μg or a vehicle from the 5th to the 15th postnatal day (pd. On the 16th pd, the rats were euthanized, and the testes were dissected, weighed, and paraffin embedded. The blood was collected to determine the serum levels of testosterone (T, estradiol (E and FSH. The following parameters were assessed in the testis sections: diameter and length of seminiferous tubules (st, numbers of spermatogonia A + intermediate + B (A/In/B, preleptotene spermatocytes (PL, leptotene + zygotene + pachytene spermatocytes (L/Z/PA and Sertoli cells per testis, percentage of st containing gonocytes or pachytene spermatocytes or lumen. An estrogenicity in vitro test was performed by means of a transgenic yeast strain expressing human estrogen receptor alpha. At both doses, DBP had no influence on testis and seminal vesicle weight, st diameter and length, number of germ and Sertoli cells per testis, percentage of st containing gonocytes or pachytene spermatocytes or lumen. DBP did not change E, T or FSH serum levels. The in vitro yeast screen showed that DBP was a weak estrogenic compound, approximately six to seven orders of magnitude less potent than 17β-estradiol. In conclusion, exposure of a rat to DBP in doses 100 or 1,000-fold higher than a Tolerable Daily Intake for humans had no effect on its testicular development. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 685–689

  20. Solubility of Hydrogen Sulfide and Methane in Ionic Liquids: 1-Ethy-3-methylimidazolium Trifluoromethanesulfonate and 1-Butyl-1-methylpyrrolidinium Trifluoromethanesulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung-Chul [Hannam University, Seoul (Korea, Republic of)

    2016-04-15

    Solubility data of hydrogen sulfide (H{sub 2}S) and methane (CH{sub 4}) in two kinds of ionic liquids with the same anion: 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][TfO]) and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([bmpyr][TfO]) are presented at pressures up to about 30 MPa and at temperatures between 303 K and 343 K. The gas solubilities in ionic liquids were determined by measuring the bubble point pressures of the gas + ionic liquid mixtures with various compositions at different temperatures using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The H{sub 2}S solubilities in ionic liquid increased with the increase of pressure and decreased with the increase of temperature. On the other hand, the CH{sub 4} solubilities in ionic liquid increased significantly with the increase of pressure, but there was little effect of temperature on the CH{sub 4} solubility. For the ionic liquds [emim][TfO] and [bmpyr][TfO] with the same anion, the solubility of H{sub 2}S as a molality basis was substantially similar, regardless of the temperature and pressure conditions as a molar concentration basis. Comparing the solubilities of H{sub 2}S and CH{sub 4} in the ionic liquid [emim][TfO], the solubilities of H{sub 2}S were much greater than those of CH{sub 4}. For the same type of ionic liquid, the solubility data of H{sub 2}S and CH{sub 4} obtained in this study were compared to the solubility data of CO2 from the literature. When compared at the same pressure and temperature conditions, the CO{sub 2} solubility was in between the solubility of H{sub 2}S and CH{sub 4}.

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

    Science.gov (United States)

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

    2013-08-28

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  3. Effect of antioxidant tertiary butyl hydroquinone on the thermal and oxidative stability of sesame oil (sesamum indicum) by ultrasonic studies.

    Science.gov (United States)

    Prasad, N; Siddaramaiah, Basavarajaiah; Banu, Mujeeda

    2015-04-01

    The aim of the current investigation is to evaluate the efficiency of tertiary butyl hydroquinone (TBHQ) as an antioxidant in sesame oil (sesamum indicum) by density, viscosity and ultrasonic velocity. The effects of varying amounts of TBHQ on the oxidation stability of sesame oil have been investigated. The antioxidant incorporated sesame oil system and control edible oil were subjected to heating at 180 ± 5 °C continuously for a period of 4 h per day for consecutive 4 days. The parameters used to assess the thermal degradation and oxidation properties of the oils include ultrasonic velocity, viscosity, density and peroxide value. The fatty acid compositions of the oils were measured by gas chromatography. Adiabatic compressibility, intermolecular free length, relaxation time and acoustic impedance have been calculated from experimental data. Viscosity, density and ultrasonic velocity change in control oil is from 3.6553 × 10(-2) to 11.1729 × 10(-2) Nsm(-2), 912.59 to 940.31 kg/m(3) and 1,421 to 1,452 m/s respectively and in sesame oil with 200 ppm TBHQ is from 3.6793 × 10(-2) to 6.4842 × 10(-2) Nsm(-2), 913.78 to 922.45 kg/m(3) and 1,421 to 1,431 m/s respectively for 16 h of heat treated oil. The ultrasonic results obtained have shown reduction in thermal degradation and improvement in oxidation stability of antioxidant loaded oil in comparison to base oil. Hence, it can be recommended that sesame oil with 200 ppm TBHQ can be used for frying without adverse effect on physical properties. The ultrasonic velocity can be used for assessment of stability of frying oil.

  4. N-butyl-2-cyanoacrylate, iso-amyl-2-cyanoacrylate andhypertonic glucose with 72% chromated glycerin in gastricvarices

    Institute of Scientific and Technical Information of China (English)

    Reda Elwakil; Mohamed Fawzy Montasser; Sara M Abdelhakam; Wesam A Ibrahim

    2015-01-01

    cyanoacrylate and a mixture of 72% chromated glycerinwith hypertonic glucose solution in management ofgastric varices.METHODS: Ninety patients with gastric varicespresented to Endoscopy Unit of Ain Shams UniversityHospital were included. They were randomly allocatedinto three groups; each group included 30 patients treatedwith intravariceal sclerosant injections in biweeklysessions till complete obturation of gastric varices;Group I (n-butyl-2-cyanoacrylate; Histoacryl?), GroupII (iso-amyl-2-cyanoacrylate; Amcrylate?) and GroupIII (mixture of 72% chromated glycerin; Scleremo?with glucose solution 25%). All the procedures wereperformed electively without active bleeding. Recruitedpatients were followed up for 3 mo.RESULTS: 26% of Scleremo group had bleeding duringpuncture vs 3.3% in each of the other two groups withsignificant difference, (P 〈 0.05). None of Scleremogroup had needle obstruction vs 13.3% in each of theother two groups with no significant difference, (P 〉0.05). Rebleeding occurred in 13.3% of Histoacryl andAmcrylate groups vs 0% in Scleremo group with nosignificant difference. The in hospital mortality was 6.6%in both Histoacryl and Amcrylate groups, while it was0% in Scleremo group with no significant difference. Inthe first and second sessions, the amount of Scleremoneeded for obturation was significantly high, while the amount of Histoacryl was significantly low. Scleremo was the less costly of the two treatments. CONCLUSION: All used sclerosant substances showed efficacy and success in management of gastric varices with no significant differences except in total amount,cost and bleeding during puncture.

  5. Exposure to butyl paraben during gestation and lactation in Hsd:Sprague dawley SD rats via dosed feed

    Directory of Open Access Journals (Sweden)

    Georgia K. Roberts

    2016-01-01

    Full Text Available Butyl paraben (BPB is an antimicrobial used in a variety of consumer products. Due to widespread human exposure and reported estrogenic activity, the National Toxicology Program quantified internal exposure during critical periods of development. Time-mated female Hsd:Sprague Dawley SD rats were administered 0, 1500, 5000 or 15,000 ppm BPB via NIH-07 feed, ad libitum, from gestation day (GD 6 to postnatal day (PND 28. Dam plasma, amniotic fluid and fetuses were collected on GD18 and pup and dam plasma were collected on PNDs 4, 10, 14, 21 and 28 and analyzed for free (unconjugated and total (unconjugated and conjugated BPB using liquid chromatography-tandem mass spectrometry. Free BPB was below the limit of quantitation in fetuses (LOQ 1.91 ng BPB/g fetus and amniotic fluid (LOQ 0.17 ng BPB/mL amniotic fluid at 1500 ppm. Analyte levels in amniotic fluid were less than 1% of maternal plasma, suggesting limited placental transfer. Total BPB in PND4 pup plasma was less than 5% of dam plasma in all exposure groups, suggesting low lactational transfer. However, at nearly all time points and exposure groups, there were higher levels of free BPB in pup versus dam plasma, suggesting limited conjugation in pups. Pup conjugation of BPB was age-dependent, not reaching the percent-conjugation in dams (>99% until PNDs 21 to 28. These data illustrate low placental and lactational transfer of dietary BPB and that poor conjugation in pups during early lactation results in higher exposure to free BPB in pups compared to dams.

  6. Portal Vein Embolization before Right Hepatectomy: Improved Results Using n-Butyl-Cyanoacrylate Compared to Microparticles Plus Coils

    Energy Technology Data Exchange (ETDEWEB)

    Guiu, Boris, E-mail: boris.guiu@chu-dijon.fr; Bize, Pierre; Gunthern, Daniel [Centre Hospitalo-Univeristaire Vaudois, Digestive and Oncologic Imaging and Interventional Radiology Unit, Department of Radiology and Interventional Radiology (Switzerland); Demartines, Nicolas; Halkic, Nermin [Centre Hospitalo-Univeristaire Vaudois, Department of Visceral Surgery (Switzerland); Denys, Alban [Centre Hospitalo-Univeristaire Vaudois, Digestive and Oncologic Imaging and Interventional Radiology Unit, Department of Radiology and Interventional Radiology (Switzerland)

    2013-10-15

    Background: There is currently no consensus in the literature on which embolic agent induces the greatest degree of liver hypertrophy after portal vein embolization (PVE). Only experimental results in a pig model have demonstrated an advantage of n-butyl-cyanoacrylate (NBCA) over 3 other embolic materials (hydrophilic gel, small and large polyvinyl alcohol particles) for PVE. Therefore, the aim of this human study was to retrospectively compare the results of PVE using NBCA with those using spherical microparticles plus coils. Methods: A total of 34 patients underwent PVE using either NBCA (n = 20), or spherical microparticles plus coils (n = 14). PVE was decided according to preoperative volumetry on the basis of contrast-enhanced CT. Groups were compared for age, sex, volume of the left lobe before PVE and future remnant liver ratio (FRL) (volume of the left lobe/total liver volume - tumor volume). The primary end point was the increase in left lobe volume 1 month after PVE. Secondary end points were procedure complications and biological tolerance. Results: Both groups were similar in terms of age, sex ratio, left lobe volume, and FRL before PVE. NBCA induced a greater increase in volume after PVE than did microparticles plus coils (respectively, +74 {+-} 69 % and +23 {+-} 14 %, p < 0.05). The amount of contrast medium used for the procedure was significantly larger when microparticles and coils rather than NBCA were used (respectively, 264 {+-} 43 ml and 162 {+-} 34 ml, p < 0.01). The rate of PVE complications as well as the biological tolerance was similar in both groups. Conclusion: NBCA seems more effective than spherical microparticles plus coils to induce left-lobe hypertrophy.

  7. CO2 Capture and Separation Properties in the Ionic Liquid 1-n-Butyl-3-Methylimidazolium Nonafluorobutylsulfonate

    Directory of Open Access Journals (Sweden)

    Lingyun Zhou

    2014-05-01

    Full Text Available Recently, the use of ionic liquids (ILs for carbon capture and separation processes has gained great interest by many researchers due to the high solubility of CO2 in ILs. In the present work, solubility measurements of CO2 in the novel IL 1-n-butyl-3-methylimidazolium nonafluorobutylsulfonate [C4mim][CF3CF2CF2CF2SO3] were performed with a high-pressure view-cell technique in the temperature range from 293.15 to 343.15 K and pressures up to about 4.2 MPa. For comparison, solubilities of H2, N2, and O2 in the IL were also measured at 323.15 K via the same procedure. The Krichevsky-Kasarnovsky equation was employed to correlate the measured solubility data. Henry’s law constants, enthalpies, and entropies of absorption for CO2 in the IL were also determined and presented. The CO2 solubility in this IL was compared with other ILs sharing the same cation. It was shown that the solubility of CO2 in these ILs follows the sequence: [C4mim][CF3CF2CF2CF2SO3] ≈ [C4mim][Tf2N] > [C4mim][CF3CF2CF2COO] > [C4mim][BF4], and the solubility selectivity of CO2 relative to O2, N2, and H2 in [C4mim][CF3CF2CF2CF2SO3] was 8, 16, and 22, respectively. Furthermore, this IL is regenerable and exhibits good stability. Therefore, the IL reported here would be a promising sorbent for CO2.

  8. Oxidative Stress, Cytotoxicity and Genotoxicity in Earthworm Eisenia fetida at Different Di-n-Butyl Phthalate Exposure Levels.

    Directory of Open Access Journals (Sweden)

    Tingting Ma

    Full Text Available Recognized as ubiquitous contaminants in soil, the environmental risk of phthalic acid esters (PAEs is of great concern recently. Effects of di-n-butyl phthalate (DnBP, an extensively used PAE compound to Eisenia fetida have been investigated in spiked natural brown yellow soil (Alfisol for soil contact test. The toxicity of DnBP to E. fetida on the activity of superoxide dismutase (SOD activity, peroxidase (POD, reactive oxygen species (ROS content, and the apoptosis of coelomocytes and DNA damage at the 7th, 14th, 21st and 28th day of the incubation have been paid close attention to. In general, SOD activity and ROS content were significantly induced, opposite to total protein content and POD activity, during the toxicity test of 28 days especially under concentrations higher than 2.5 mg kg-1. The reduction in neutral red retention (NRR time along with the increase of dead coelomocytes as the increasing of DnBP concentrations, indicating severe damage to cell viability under varying pollutant stress during cultivation, which could also be proved by comet assay results for exerting evident DNA damage in coelomocytes. DnBP in spiked natural soil could indeed cause damage to tissues, coelomocytes and the nucleus of E. fetida. The key point of the apparent change in different indices presented around 2.5 mg DnBP kg-1 soil, which could be recommended as the threshold of DnBP soil contamination, so that further investigation on threshold values to other soil animals or microorganisms could be discussed.

  9. Preparation and Performance of Poly(butyl fumarate-Based Material for Potential Application in LED Encapsulation

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2017-02-01

    Full Text Available A UV-curable poly(butyl fumarate (PBF/poly(propylene fumarate-diacrylate (PPF-DA hybrid material with good performance for LED encapsulation is introduced in the paper. They have been prepared by radical polymerization using PBF and PPF-DA macromers with a UV curing system. PBF and PPF-DA were characterized by Fourier-transform infrared (FT-IR and H-nuclear magnetic resonance (1H NMR. The thermal behavior, optical and mechanical properties of the material were examined by thermogravimetric analysis (TGA, differential scanning calorimetry (DSC, ultraviolet-visible spectroscopy (UV–vis, and a material testing system mechanical testing machine, respectively. The results indicated that the hybrid material has a suitable refractive index (n = 1.537 and high transmittance (99.64% in visible range before/after thermal aging. With the increasing of the double bond ratio from 0.5 to 2, the water absorption ratios of the prepared encapsulation material were 1.22%, 1.87% and 2.88%, respectively. The mechanical property experiments showed that bonding strength was in the range of 1.86–3.40 MPa, tensile-shear strength ranged from 0.84 MPa to 1.57 MPa, and compression strength was in the range of 5.10–27.65 MPa. The cured PBF/PPF-DA hybrid material can be used as a light-emitting diode (LED encapsulant, owing to its suitable refractive index, high transparency, excellent thermal stability, lower water absorption, and good mechanical properties.

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

    Science.gov (United States)

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

    2011-01-01

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

  11. Effect of antioxidant butylated hydroxyl anisole on the thermal or oxidative stability of sunflower oil (Helianthus Annuus) by ultrasonic.

    Science.gov (United States)

    Murari, Satish Kumar; Shwetha, M V

    2016-01-01

    The aim of the current investigation was to evaluate the efficiency of butylated hydroxyl anisole (BHA) as an antioxidant in sunflower oil (Helianthus Annuus). The oxidation stability of sunflower oil have been investigated by the effects of varying amounts of BHA. The antioxidant incorporated sunflower oil system and control edible oil were subjected to heating at 180 ± 5 °C continuously for a period of 4 h per day for consecutive 4 days. The parameters used to assess the thermal degradation and oxidation properties of the oils include ultrasonic velocity, viscosity, density and peroxide value. The fatty acid compositions of the oils were measured by gas chromatography. Adiabatic compressibility, intermolecular free length, relaxation time and acoustic impedance have been calculated from experimental data. Viscosity, density and ultrasonic velocity change in control oil is from 3.72 × 10(-2) to 13.2 × 10(-2) Nsm - 2, 918 to 994 kg/m3 and 1412 to 1484 m/s respectively and in sunflower oil with 200 ppm BHA is from 3.88 × 10(-2) to 7.52 × 10(-2) Nsm - 2, 926 to 962 kg/m3 and 1418 to 1463 m/s respectively for 16 h of heat treated oil. The ultrasonic results obtained have shown reduction in thermal degradation and improvement in oxidation stability of antioxidant loaded oil in comparison to base oil. Hence, it can be recommended that sunflower oil with 200 ppm BHA can be used for frying without adverse effect on physical properties. The ultrasonic velocity can be used for assessment of stability of frying oil.

  12. Preparation and application of sustained release microcapsules of potassium ferrate(VI) for dinitro butyl phenol (DNBP) wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wang Huilong, E-mail: davidwang_71@yahoo.com.cn [Department of Chemistry, Dalian University of Technology, Dalian 116023 (China); Liu Shuqin [Department of Chemistry, Dalian University of Technology, Dalian 116023 (China); Zhang Xiuyan [Dalian Fishery Technical Extension Center, Dalian 116023 (China)

    2009-09-30

    The encapsulated potassium ferrate(VI) (K{sub 2}FeO{sub 4}) samples were successfully prepared by phase separation method in organic solvents. The ethyl cellulose and paraffin were selected for the microcapsule wall materials (WM). The as prepared microcapsules were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The stability can be enhanced greatly when ferrate(VI) was encapsulated in the microcapsules with a mass ratio of Fe(VI):WM in the range of 1:1-1:3 for the same conserved time in air compared for pure K{sub 2}FeO{sub 4}. The sustained release behavior of the microcapsules with different Fe(VI):WM mass ratios in 8.0 M KOH solution was also investigated. The results indicated that the Fe(VI) release was reduced with increase of Fe(VI):WM mass ratios from 1:1 to 1:3. The release kinetics of the microcapsules is found to obey Ritger-Peppas equation. The prepared Fe(VI) microcapsules has been used for the removal of a typical alkyl dinitro phenol compound, 2-sec-butyl-4,6-dinitrophenol (DNBP), from aqueous solution. The effect of pH, microcapsule concentration and reaction time was studied thoroughly. The optimal pH for DNBP degradation was 6.5, and at this pH and a microcapsule concentration of 1.2 g/L, approximately 93% of the DNBP was degraded after 80 min. The encapsulated ferrate(VI) samples were found to be very effective in the decolorization and COD reduction of real wastewater from DNBP manufacturing. Thus, this study showed the feasible and potential use of encapsulated Fe(VI) samples in degradation of various toxic organic contaminants and industrial effluents.

  13. Promotion of liver and kidney carcinogenesis by ethyl tertiary-butyl ether (ETBE) in male Wistar rats.

    Science.gov (United States)

    Hagiwara, Akihiro; Doi, Yuko; Imai, Norio; Suguro, Mayuko; Kawabe, Mayumi; Furukawa, Fumio; Tamano, Seiko; Nagano, Kasuke; Fukushima, Shoji

    2015-10-01

    Tumor-promoting effects of ethyl tertiary-butyl ether (ETBE) were investigated in a 2-stage carcinogenesis bioassay with regard to hepatic and renal carcinogenesis in rats. Male 6-week-old Wistar rats were given drinking water containing N-ethyl-N-(2-hydroxyethyl)nitrosamine (EHEN), as an initiator, at a dose of 500 ppm for 2 weeks. Starting one week thereafter, the animals were administered ETBE at dose levels of 0 (control), 100, 300, 500 or 1,000 mg/kg/day by gavage for 19 weeks from week 4 to 22. Necropsy of all rats was performed at week 23, and livers and kidneys were examined histopathologically. Incidences of hepatocellular adenomas, and those of combined hepatocellular adenomas and carcinomas were significantly elevated in rats given 1,000 mg/kg/day ETBE, but not 100‒500 mg/kg/day ETBE, and there was a significant increase in the average numbers of lesions. No significant differences in incidences and average numbers of renal tubule neoplasms were found in rats administered 100‒1,000 mg/kg/day ETBE. However, the average numbers of atypical tubule hyperplasias, considered to be preneoplastic lesions, were significantly increased in rats given ETBE at 1,000 mg/kg/day, but not in rats given 500 mg/kg/day or lower doses. Thus, these results imply that ETBE has hepatic and renal tumor-promoting activities that affect EHEN-induced carcinogenesis in male rats, and the no-observed-effect level is 500 mg/kg/day under the present experimental conditions.

  14. Sol-Gel固定磷钨酸催化合成乙酸丁酯%Synthesis of Butyl Acetate Catalyzed by Phosphotungstic Acid Immobilized on Sol-Gel

    Institute of Scientific and Technical Information of China (English)

    成凤桂; 欧知义

    2001-01-01

    制备了正硅酸乙酯凝胶(Sol-Gel)固定磷钨酸催化剂,催化合成乙酸丁酯.实验表明:Sol-Gel与磷钨酸的质量比为15∶1时催化性能最高,在催化剂用量为总反应物质量的5 %、酸醇比为1.5∶1、反应温度为105 °C、反应时间3.5 h的条件下,酯产率可达87 %以上.催化剂易与产物分离,重复使用8次催化效果仍然较好.%The phosphotungstic acid immobilized on Sol-Gel were prepared and used for synthesising butyl acetate from n-butyl alcohol and acetic acid.The catalysis activity was highest when mass ratio of tetraethoxysilane(TEOS) to phosphotungstic acid was 15∶1. The optimum condition of the reaction were determined: the moiar ratio of acetic acid to n-butyl alcohol was 1.3∶1, the amount of catalyst was about 5 % of the mass of reactants, reaction temperature is 105 °C for 3.5 h. Under the optimum condition the yieid of esters is above 87 %. The catalyst could be easily separated from the products. Reusing of its catalysis activity is still well used for 8 times.

  15. Research of the Regeneration of Waste Cross-linked Brominated Butyl-Rubber%交联溴化丁基橡胶的再生研究

    Institute of Scientific and Technical Information of China (English)

    刘旭

    2012-01-01

    采用天然再生剂大蒜汁并结合开炼、密炼等再生方法对废溴化丁基橡胶的再生情况进行探讨。结果表明:开炼温度、开炼时间、密炼温度、密炼时间及再生剂用量对再生效果均有影响,且在这些因素中,再生剂为主导因素。在开炼温度为55℃、开炼时间为10min、加入再生剂用量为6%时再生效果最佳;密炼温度为125℃、密炼时间10min、再生剂用为6%时取得最佳再生效果。%The waste cross-linked brominated butyl-rubber was regenerated with the garlic juice by mixing and banburying in this paper.The result showed that:The factors influence the regenerated rubber properties were discussed,such as the temperature and time of mixing and banburying,the dosage of the garlic juice and so on.Among these factors the dosage of garlic juice was the main factor.When the cross-linked brominated butyl-rubber was regenerated with garlic juice by mixing,the optimal temperature was 55℃,the time was 10 minutes,and the dosage of garlic juice was 6%.When the cross-linked brominated butyl-rubber was regenerated with garlic juice by banburying,the optimal temperature was 125℃,the time was 10 minutes,and the dosage of garlic juice was 6%.

  16. 固体超强酸催化合成己酸丁酯%Synthesization of Butyl Hexanoate Catalyzed by Solid Superacid

    Institute of Scientific and Technical Information of China (English)

    王赵志; 闫鹏; 陈志胜

    2011-01-01

    Butyl hexanoate was synthesized by the material of hexanoic acid and n-butyl alcohol,using solid superacid S2O82-/SnO2-SiO2 as catalyst.The effects of steep concentration,mole ratio of Sn to Si,calcination temperature,acid/alcohol ratio,reaction time,and catalyst amount on esterification reaction were studied and the appropriate reaction conditions were as follow: the mole ratio of n-butyl alcohol to hexanoic acid was 3:1,the amount of catalyst to hexanoic acid(0.1 mol) was 0.50 g,and reaction time was 2.0 h.Under the appropriate conditions,the esterification rate was up to 99.1%.%以固体超强酸S2O82-蛐SnO2-SiO2为催化剂,己酸和正丁醇为原料,合成酒用香料己酸丁酯.考察了浸渍液浓度、锡硅摩尔比、焙烧温度、酸醇摩尔比、反应时间、催化剂用量等条件对酯化率的影响,得出了适宜的催化剂制备条件和酯化反应条件.当取己酸用量为0.1 mol,n(正丁醇):n(己酸)=3:1,反应时间为2.0 h,催化剂用量为0.50 g时,酯化率可达99.1%.

  17. Oxidation of methyl tert-butyl ether by alkane hydroxylase in dicyclopropylketone-induced and n-octane-grown Pseudomonas putida GPo1.

    Science.gov (United States)

    Smith, Christy A; Hyman, Michael R

    2004-08-01

    The alkane hydroxylase enzyme system in Pseudomonas putida GPo1 has previously been reported to be unreactive toward the gasoline oxygenate methyl tert-butyl ether (MTBE). We have reexamined this finding by using cells of strain GPo1 grown in rich medium containing dicyclopropylketone (DCPK), a potent gratuitous inducer of alkane hydroxylase activity. Cells grown with DCPK oxidized MTBE and generated stoichiometric quantities of tert-butyl alcohol (TBA). Cells grown in the presence of DCPK also oxidized tert-amyl methyl ether but did not appear to oxidize either TBA, ethyl tert-butyl ether, or tert-amyl alcohol. Evidence linking MTBE oxidation to alkane hydroxylase activity was obtained through several approaches. First, no TBA production from MTBE was observed with cells of strain GPo1 grown on rich medium without DCPK. Second, no TBA production from MTBE was observed in DCPK-treated cells of P. putida GPo12, a strain that lacks the alkane-hydroxylase-encoding OCT plasmid. Third, all n-alkanes that support the growth of strain GPo1 inhibited MTBE oxidation by DCPK-treated cells. Fourth, two non-growth-supporting n-alkanes (propane and n-butane) inhibited MTBE oxidation in a saturable, concentration-dependent process. Fifth, 1,7-octadiyne, a putative mechanism-based inactivator of alkane hydroxylase, fully inhibited TBA production from MTBE. Sixth, MTBE-oxidizing activity was also observed in n-octane-grown cells. Kinetic studies with strain GPo1 grown on n-octane or rich medium with DCPK suggest that MTBE-oxidizing activity may have previously gone undetected in n-octane-grown cells because of the unusually high K(s) value (20 to 40 mM) for MTBE.

  18. Studies on the detoxification effects and acute toxicity of a mixture of cis-sec-butyl-1-propoenyl disulphide and trans-sec-butyl-1-propoenyl disulphide isolated from crude essential oil of Ferula sinkiangensis K.M. Shen, a Chinese traditional herbal medicine.

    Science.gov (United States)

    Ye, Bengui; Wang, Shu; Zhang, Li

    2011-07-01

    There have, so far, been no papers about the detoxification effects on morphine-dependent animals of a mixture of cis-sec-butyl-1-propoenyl disulphide and trans-sec-butyl-1-propoenyl disulphide (SBD), which is isolated from crude essential oil of Ferula sinkiangensis K.M. Shen, a Chinese traditional herbal medicine. Naloxone-precipitated abstinent morphine-dependent models and naturally abstinent morphine-dependent models were used to evaluate the detoxification effects of intraperitoneal injection of SBD. In addition, the writhing test for mice was used to assess the anti-nociceptive effects of SBD, and the spontaneous activity test was used to verify the sedative effects of SBD. Acute toxicity tests of the SBD in mice were performed and the LD₅₀ values were calculated. The results indicated that SBD can inhibit the abstinent syndromes, and that SBD had good anti-nociceptive and sedative effects.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-09-15

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

  20. A New Flow Control Technique Using Diluted Epinephrine in the N-butyl-2-cyanoacrylate Embolization of Visceral Artery Pseudoaneurysms Secondary to Chronic Pancreatitis

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Hiroyuki, E-mail: hmorif@koto.kpu-m.ac.jp [Japan Red Cross Kyoto Daiichi Hospital, Department of Diagnostic Radiology (Japan); Yamagami, Takuji [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science (Japan); Takeuchi, Yoshito [National Cancer Center, Division of Diagnostic Radiology (Japan); Matsumoto, Tomohiro; Asai, Shunsuke; Masui, Koji [Japan Red Cross Kyoto Daiichi Hospital, Department of Diagnostic Radiology (Japan); Sato, Hideki [Japan Red Cross Kyoto Daiichi Hospital, Department of Gastroenterology (Japan); Taniguchi, Fumihiro [Japan Red Cross Kyoto Daiichi Hospital, Department of Surgery (Japan); Sato, Osamu [Japan Red Cross Kyoto Daiichi Hospital, Department of Diagnostic Radiology (Japan); Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science (Japan)

    2012-08-15

    Although n-butyl-2-cyanoacrylate (NBCA) has been used as an effective liquid embolization material, its indication for pseudoaneurysms has seemingly been limited because of the technical difficulties of using NBCA, such as reflux to the parent artery and causing significant infarction. Thus, considerable skill in using NBCA or a device to control blood flow during its polymerization is required to achieve embolization without severe complications. We report our new technique for controlling blood flow using diluted epinephrine in transcatheter arterial NBCA embolization of five pseudoaneurysms in four cases secondary to hemosuccus pancreaticus.

  1. EFFECTS OF ω-ACRYLOYL POLY(ETHYLENE OXIDE) MACROMONOMER ON EMULSIFIER-FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE AND n-BUTYL ACRYLATE

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macromonomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxide with diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction terminating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emulsion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containing various concentrations of PEO-A was studied. In all cases stable emulsion coplymerizations of MMA and BA were obtained. The stabilizing effect was found to be dependent on the molecular weight and the feed amount of the macromonomer.

  2. N-butyl cyanoacrylate embolization with blood flow control of an arterioportal shunt that developed after radiofrequency ablation of hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Sonomura, Tetsuo; Kawai, Nobuyuki; Kishi, Kazushi [Wakayama Medical University, Wakayama (Japan); and others

    2014-04-15

    We present a case of a patient with rapid deterioration of esophageal varices caused by portal hypertension accompanied by a large arterioportal shunt that developed after radiofrequency ablation of hepatocellular carcinoma. We used n-butyl cyanoacrylate (NBCA) as an embolic material to achieve pinpoint embolization of the shunt, because the microcatheter tip was 2 cm away from the shunt site. Under hepatic arterial flow control using a balloon catheter, the arterioportal shunt was successfully embolized with NBCA, which caused an improvement in the esophageal varices.

  3. Delayed, life-threatening lower gastrointestinal hemorrhage in an infant after serial transverse enteroplasty: treatment with transcatheter n-butyl-2-cyanoacrylate embolization

    Energy Technology Data Exchange (ETDEWEB)

    Bogue, Conor O.; Alzahrani, Amin I.; John, Philip R.; Amaral, Joao G. [Hospital for Sick Children, Division of Image Guided Therapy, Department of Diagnostic Imaging, Toronto (Canada); Wales, Paul W. [Hospital for Sick Children, Department of Surgery and the Group for Improvement of Intestinal Function and Treatment (GIFT), Toronto (Canada)

    2009-10-15

    We report a case of n-butyl-2-cyanoacrylate glue embolization of life-threatening lower gastrointestinal (LGI) hemorrhage in a 10-month-old boy. The child had a history of gastroschisis and short-bowel syndrome. Six months prior to the LGI bleed, he had undergone a serial transverse enteroplasty (STEP) to lengthen his intestine. To the best of our knowledge this is both the first report of successful glue embolization for LGI bleeding in a child and also the first report of severe hemorrhage after the STEP procedure. (orig.)

  4. Dosimetric characteristics of a radiochromic polyvinyl butyral film containing 2,4-hexadiyn-1,6-bis(n-butyl urethane).

    Science.gov (United States)

    Abdel-Fattah, A A; Soliman, Y S; Bayomi, A M M; Abdel-Khalek, A A

    2014-04-01

    A radiation-sensitive compound 2,4-hexadiyn-1,6-bis(n-butyl urethane) (HDDBU) was synthesized, characterized by FTIR spectroscopy, and introduced into a thin polyvinyl butyral film to form a radiation dosimeter for industrial irradiation facilities. The monomer polymerizes under gamma radiation, inducing change in the film spectrum in the range of 200-400 nm. According to XRD spectroscopy, the film contains monomeric HDDBU in a non-crystalline state. The dose response function, radiation sensitivity, and dependences of the response on environmental factors were studied. Uncertainty of dose measurements with the proposed dosimetry system was analyzed in detail.

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  6. Intramolecular interactions between chalcogen atoms: organoseleniums derived from 1-bromo-4-tert-butyl-2,6-di(formyl)benzene.

    Science.gov (United States)

    Zade, Sanjio S; Panda, Snigdha; Singh, Harkesh B; Sunoj, Raghavan B; Butcher, Ray J

    2005-04-29

    [structure: see text] The synthesis and characterization of a series of low-valent organoselenium compounds derived from 1-bromo-4-tert-butyl-2,6-di(formyl)benzene (22) is described. The synthesis of diselenide 25 was achieved by the lithiation route whereas bis(4-tert-butyl-2,6-di(formyl)phenyl) diselenide (26) was synthesized by treating 22 with disodium diselenide. A series of monoselenides (27, 28, and 29) was obtained by facile nucleophilic substitution of bromine in 22, using the corresponding selenolates as nucleophiles. The halogenation reactions of bis(4-tert-butyl-2,6-di(formyl)phenyl) diselenide (26) did not afford the corresponding selenenyl halides but resulted in the isolation of an unexpected cyclic selenenate ester 34 as a product. The selenide 32 was synthesized by the treatment of dimethoxymethyl diselenide with trilithiated 2-bromo-5-tert-butyl-N,N'-di(phenyl)isophthalamide. The existence of potential Se...O intramolecular nonbonding interactions was examined by IR, (1)H, and (77)Se NMR spectroscopy, X-ray crystallography, and computational studies. The X-ray crystal structures of 26 and 27, having two ortho formyl groups, reveal the absence of any Se...O interactions. However, the Se...O interactions were observed in the selenenate ester 34 where one of the formyl groups has been utilized for the selenenate ring formation. The crystal structures of 26 and 27 exhibited intermolecular short-range C-H...Se interactions (hydrogen bonding). Although there are four heteroatoms in carbamoyl moieties ortho to selenium capable of forming a five-membered ring on intramolecular coordination, no such intramolecular Se...X (X = N, O) interaction was observed in the crystal structure of 32. The density functional theory calculations at the B3LYP/6-31G* level predicted that for all the diformyl systems (47a-c, 48a-c), the anti,anti conformer (when both formyl oxygen atoms point away from the selenium) is more stable. This preference was found to be reversed in

  7. New approach of solid-phase microextraction improving the extraction yield of butyl and phenyltin compounds by combining the effects of pressure and type of agitation.

    Science.gov (United States)

    Darrouzès, Jérôme; Bueno, Maïté; Pécheyran, Christophe; Holeman, Michel; Potin-Gautier, Martine

    2005-04-22

    A new methodology for the simultaneous and fast solid-phase microextraction (SPME) of butyl- and phenyltin compounds, as ethylated derivates, is proposed in this paper. The effects of pressure and type of agitation during headspace SPME sampling are evaluated and discussed on the basis of thermodynamic considerations. Quantitative structure-activity relationships were used to estimate analytes partition coefficients allowing to explain the different behaviours experimentally observed. SPME sampling conditions including mechanical stirring and reduced pressure result in simultaneous higher efficiency (detection limits especially lowered for phenyltins up to a eight-fold reduction) and shorter sampling time (two-fold reduction).

  8. Densities and Viscosities of the Ternary Mixtures Water + Butyl Acetate + Methanol and Water + Ethyl Propionate + Methanol at 303.15 K

    OpenAIRE

    Zoran P. Visak; Ferreira, Abel G. M.; Fonseca, Isabel M. A.

    2000-01-01

    The excess molar volumes, VE, and viscosity deviations, Δη, were calculated from the measured density and viscosity values over the whole miscibility composition ranges for the ternary systems water + butyl acetate + methanol and water + ethyl propionate + methanol and their constituent binaries, at 303.15 K and atmospheric pressure. A Redlich−Kister type equation was used to correlate binary VE and Δη data, as well as the ternary data. This equation was used to calculate the above referred p...

  9. Determination of Butyl Xanthate in Surface Water by Ion Chromatography%离子色谱法检测地表水中丁基黄原酸

    Institute of Scientific and Technical Information of China (English)

    方黎; 黄洪波; 吴杰; 苏宇亮

    2011-01-01

    Objective: The method for determination of butyl xanthate in surface water is studied by ion chromatography.Methods: Based on the stability of butyl xanthate in alkaline medium, regulate the pH to 9.2, IonPac AS20 column was used as separation column, eluted with 30mmol/L NaOH at flow rate of 1mL/min, 1ml sample injection volume and conductivity detection were used.Results: The better linear range for butyl xanthate was 5-200μg/L ,the method detection limit was 2.0μg/L,the recovery in the standard addition test was93.1%,and R.S.D.was 3.21%.Conclusion: The detection method has advantage of simplicity, sensitivity and repeatability, can satisfy the measurement of butyl xanthate in surface wate.%目的研究了离子色谱检测地表水中的丁基黄原酸的分析方法.方法利用丁基黄原酸在碱性介质中的稳定性,调节水样pH为9.2,以IonPac AS20柱分离,30mmol/L NaOH为淋洗液,1.OmL/min流速,1ML进样,电导检测.结果丁基黄原酸在5~200μg/L浓度范围呈良好的线性关系,方法检测限为2.0μg/L,水样平均加标回收率为93.1%,相时标准偏差为3.21%.结论该方法操作简便、灵敏度高、重现性好,适合于地表水的检测.

  10. Physicochemical properties of poly(lactic acid-co-glycolic acid film modified via blending with poly(butyl acrylate-co-methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Guoquan Zhu

    2013-01-01

    Full Text Available A series of poly(lactic acid-co-glycolic acid (PLGA/poly(butyl acrylate-co-methyl methacrylate (P(BA-co-MMA blend films with different P(BA-co-MMA mole contents were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLGAP(BA-co-MMA blend films were studied by scanning electron microscopy (SEM. Thermal, mechanical, and chemical properties of PLGAP(BA-co-MMA blend films were investigated by differential scanning calorimeter (DSC, thermogravimetric analysis (TGA, tensile tests, and surface contact angle tests. The introduction of P(BA-co-MMA could modify the properties of PLGA films.

  11. Bis({tris[2-(3,5-di-tert-butyl-2-oxido-benzylideneamino)ethyl]amine}cerium(III)) diethyl ether solvate.

    Science.gov (United States)

    Dröse, Peter; Hrib, Cristian G; Edelmann, Frank T

    2010-10-13

    The title compound, 2[Ce(C(51)H(75)N(4)O(3))]·C(4)H(10)O, was obtained in high yield (92%) by reduction of (TRENDSAL)Ce(IV)Cl [TRENDSAL is N,N',N''-tris-(3,5-di-tert-butyl-salicyl-ide-natoamino)-triethyl-amine] with potassium in THF. The bulky tripodal TRENDSAL ligand effectively encapsulates the central Ce(III) cation with a Ce-N(imine) distance of 2.860 (2) Å and an average C-N(amine) distance of 2.619 Å within a distorted monocapped octahedral coordination.

  12. Effect of O-4-ethoxyl-butyl-berbamine in combination with pegylated liposomal doxorubicin on advanced hepatoma in mice

    Institute of Scientific and Technical Information of China (English)

    Bai-Jun Fang; Mei-Li Yu; Shao-Guang Yang; Lian-Ming Liao; Jie-Wen Liu; Robert-C-H Zhao

    2004-01-01

    AIM:To study the synergistic effects of calmodulin (CaM) antagonist O-4-ethoxyl-butyl-berbamine (EBB) and pegylated liposomal doxorubicin (PLD) on hepatoma-22 (H22)in vivo.METHODS: Hepatoma model was established in 50 Balb/c mice by inoculating H22 cells (2.5x106) subcutaneously into the right backs of the mice. These mice were divided into 5 groups, and treated with saline only, PLD only, doxorubicin (Dox) only, PLD plus EBB and Dox plus EBB, respectively.In the treatment groups, mice were given 5 intravenous of PLD or Dox on days 0, 3, 6, 9 and 12. The first dosage of PLD or Dox was 4.5 mg/kg, the other 4 injections was 1 mg/kg.EBB (5 mg/kg)was coadministered with PLD or Dox in the corresponding groups. The effect of drugs on the life spans of hepatoma-bearing mice and tumor response to the drugs were recorded. Dox levels in the hepatoma cells were measured by a fluorescence assay. Light microscopy was performed to determine the histopathological changes in the major organs of these tumor-bearing mice. The MTT method was used to analyze the effect of Dox or PLD alone,Dox in combination with EBB, or PLD in combination with EBB on the growth of H22 cells in an in vitro experiment.RESULTS: EBB (5 mg/kg) significantly augmented the antitumor activity of Dox or PLD, remarkably prolonged the median survival time. The median survival time was 18.2 d for control group, but 89.2 d for PLD+EBB group and 70.1 d for Dox+EBB group, respectively. However,Dox alone did not show any remarkable antitumor activity,and the median survival time was just 29.7 d. Addition of EBB to Dox or PLD significantly increased the level of Dox in H22 cells in vivo. Moreover, EBB diminished liver toxicity of Dox and PLD.In vitro, EBB reduced the IC50 value of Dox or PLD on H22cells from 0.050±0.006 mg/L and 0.054±0.004 mg/L to 0.012±0.002 mg/L and 0.013±0.002 mg/L, respectively (P<0.01).CONCLUSION: EBB and liposomization could improve the therapeutic efficacy of Dox in liver cancer, while

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

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

  14. Inorganic arsenic in drinking water accelerates N-butyl-N-(4-hydroxybutyl)nitrosamine-induced bladder tissue damage in mice

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Paul-Yann [Department of Pathology, Chang Gung Memorial Hospital at Chiayi, Chang Gung University, Chiayi, Taiwan (China); Lin, Yung-Lun; Huang, Chin-Chin; Chen, Sin-Syu [Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan (China); Liu, Yi-Wen, E-mail: ywlss@mail.ncyu.edu.tw [Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan (China)

    2012-02-15

    Epidemiological studies have revealed that exposure to an arsenic-contaminated environment correlates with the incidence of bladder cancer. Bladder cancer is highly recurrent after intravesical therapy, and most of the deaths from this disease are due to invasive metastasis. In our present study, the role of inorganic arsenic in bladder carcinogenesis is characterized in a mouse model. This work provides the first evidence that inorganic arsenic in drinking water promotes N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced bladder tissue damage, including the urothelium and submucosal layer. This damage to the bladder epithelium induced by BBN includes thickening of the submucosal layer, the loss of the glycosaminoglycan layer and an increase in both the deoxyguanosine oxidation and cytosine methylation levels in the DNA. Further, when 10 ppm inorganic arsenic is combined with BBN, the number of bladder submucosal capillaries is increased. In addition, inorganic arsenic also increases the deoxyguanosine oxidation level, alters the cytosine methylation state, decreases the activities of glutathione reductase and glucose-6-phosphate dehydrogenase, decreases the protein expression of NAD(P)H quinone oxidoreductase-1 (NQO-1) and increases the protein expression of specific protein 1 (Sp1) in bladder tissues. In summary, our data reveal that inorganic arsenic in drinking water promotes the BBN-induced pre-neoplastic damage of bladder tissue in mice, and that the 8-hydroxy-2′-deoxyguanosine, 5-methylcytosine, NQO-1 protein and Sp1 protein levels may be pre-neoplastic markers of bladder tumors. -- Highlights: ► The role of inorganic arsenic in bladder carcinogenesis is characterized in mice. ► We examine the changes in the histology and biochemistry of bladder tissues. ► Inorganic arsenic enhances BBN-induced DNA oxidation while decreases BBN-induced DNA methylation in the mouse bladder. ► Inorganic arsenic alters the activities of the anti-oxidant enzymes in

  15. Spectroscopic study of the electrochemical behaviour of tantalum(V) chloride and oxochloride species in 1-butyl-1-methylpyrrolidinium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Babushkina, Olga B., E-mail: olga.babushkina@cest.a [Centre in Electrochemical Surface Technology (CEST), Viktor Kaplan street 2, A-2700, Wiener Neustadt (Austria); Ekres, Silvia [Centre in Electrochemical Surface Technology (CEST), Viktor Kaplan street 2, A-2700, Wiener Neustadt (Austria)

    2010-12-30

    FTIR spectroscopy was used to identify the oxochloride species of tantalum(V) in ionic liquids and to confirm the correlations between their presence in electrolytes and the changes in the route of electrochemical reduction of tantalum(V). Electrochemical behaviour of the mixtures (x)1-butyl-1-methyl-pyrrolidinium chloride-(1 - x)TaCl{sub 5} at x = 0.80, 0.65, and 0.40 was investigated over the temperature range 90-160 {sup o}C with respect to the electrochemical deposition of tantalum and was discussed in terms of spectroscopic data. The mechanism of electrochemical reduction of tantalum(V) in the basic and acidic electrolytes depends strongly on the structure and composition of the electro active species of tantalum(V) defined by the molar composition of ionic liquids and on the competition between tantalum(V) chloride and oxochloride species. In the basic mixture at x = 0.80, with octahedral [TaCl{sub 6}]{sup -} ions as the electrochemically active species only the first reduction step Ta{sup 5+} {yields} Ta{sup 4+} at -0.31 V was observed. The competitive reduction of tantalum(V) oxochloride species occurs at more anodic potential (-0.01 V) than the reduction of the chloride complexes and can restrict the further reduction of tantalum(IV). In the basic ionic liquid at x = 0.65, the cyclic voltammograms exhibit reduction peaks at -0.31 V and -0.51 V attributed to the diffusion controlled process as [TaCl{sub 6}]{sup -} + e{sup -} {yields} [TaCl{sub 6}]{sup 2-} and [TaCl{sub 6}]{sup 2-} + e{sup -} {yields} [TaCl{sub 6}]{sup 3-}. The further irreversible reduction of tantalum(III) to metallic state may occur at -2.1 V. In the acidic ionic liquids, at x = 0.40 the electrochemical reduction of two species occurs, TaCl{sub 6}{sup -} and Ta{sub 2}Cl{sub 11}{sup -} and it is limited by two electron transfer for both of them at -0.3 V and -1.5 V, respectively.

  16. Synthesis and Crystal Structure of 4,6-Di-tert-butyl-2-hydroxy-3-(N-1-phenylethyliminomethyl)phenyl bis(triphenylphosphine)palladium bromide

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The title compound (C59H60BrNOP2Pd, Mr=1047. 3) was synthesized in good yield from α-methylbenzylamine and 4,6-di-tert-butyl-3-formyl-2-hyd roxyphenyl bis( triphenylphosphine)palladium bromide. The latter was obtained from 3-bromo-4,6 -di -tert-butyl-2-hydroxybenzaldehyde and tetrakis(triphenylphosphine)palladium. It crystallizes in monoclinic space group P21/c with the cell dimensions a= 17.882(4 ), b=11.065(2), c=26.143(5)(A), β=90.55(3)°, V=5173(3)(A)3, Z=4, Dc=1.233g cm-3, F(00 0)=2160, μ=1.233 mm-1. The structure was solved by direct methods and r efined by full matrix least-square method, and the final crystallographic discrepancy fa c tor is 0.0647 for 5467 observed reflections. The crystal structure determination of the title compound shows that the coordination environment around the Pd cen tre is tetragonal with two Pd-P bonds of 2.333(2)(A)and 2.339(2)(A), respectively , a Pd-Br length of 2.536(1) and a Pd-C bond of 2.032(8).

  17. Vibrational sum-frequency generation spectroscopy of ionic liquid 1-butyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate at the air-water interface

    Science.gov (United States)

    Saha, Ankur; SenGupta, Sumana; Kumar, Awadhesh; Choudhury, Sipra; Naik, Prakash D.

    2016-08-01

    The structure and orientation of room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate [PF3(C2F5)3], commonly known as [bmim][fap], have been investigated at the air-[bmim][fap] and air-water interfaces, employing vibrational sum-frequency generation (VSFG) spectroscopy. The VSFG spectra in the CH stretch region suggest presence of the [bmim] cation at the interfaces. Studies reveal that the butyl chain protrudes out into air, and the imidazolium ring lies almost planar to the interface. The CH stretch intensities get enhanced at the air-water interface, mainly because of polar orientation of imidazolium cation induced by interfacial water molecules. The OH stretch intensities are also enhanced at the air-water interface due to polar orientation of interfacial water molecules induced by [bmim][fap]. The Brewster angle microscopy suggests self aggregation of [bmim][fap] in the presence of water, and the aggregation becomes extensive showing dense surface domains with time. However, the surface pressure is almost unaffected due to aggregation.

  18. 对叔丁基邻苯二酚混合物组成测定法%Detection Method of Tert-butyl Catechol Mixture Composition

    Institute of Scientific and Technical Information of China (English)

    高山

    2013-01-01

      文章对对叔丁基邻苯二酚混合物组成的测定法进行了充分的论证,并得出 SE-54、20 m 毛细管色谱柱可用于对叔丁基邻苯二酚产品组分分析。较佳操作条件为:载气压力:0.08 MPa;柱温:170℃;汽化室温度:300℃;检测器温度250℃;进样量:0.2μL。%Full demonstration of detection method of Tert-butyl catechol mixture composition was made in the paper. The Capillary Column of SE-54, 20 m can be used in Tert-butyl catechol product component analysis. The better operation conditions were the pressure of the carrier gas was 0.08 MPa, column temperature was 170 ℃, vaporizing chamber temperature was 300 ℃, detector temperature was 250 ℃, injection volume was 0.2 μL.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  20. Determination of arsenic species in solid matrices utilizing supercritical fluid extraction coupled with gas chromatography after derivatization with thioglycolic acid n-butyl ester.

    Science.gov (United States)

    Wang, Zhifeng; Cui, Zhaojie

    2016-12-01

    A method using derivatization and supercritical fluid extraction coupled with gas chromatography was developed for the analysis of dimethylarsinate, monomethylarsonate and inorganic arsenic simultaneously in solid matrices. Thioglycolic acid n-butyl ester was used as a novel derivatizing reagent. A systematic discussion was made to investigate the effects of pressure, temperature, flow rate of the supercritical CO2 , extraction time, concentration of the modifier, and microemulsion on extraction efficiency. The application for real environmental samples was also studied. Results showed that thioglycolic acid n-butyl ester was an effective derivatizing reagent that could be applied for arsenic speciation. Using methanol as modifier of the supercritical CO2 can raise the extraction efficiency, which can be further enhanced by adding a microemulsion that contains Triton X-405. The optimum extraction conditions were: 25 MPa, 90°C, static extraction for 10 min, dynamic extraction for 25 min with a flow rate of 2.0 mL/min of supercritical CO2 modified by 5% v/v methanol and microemulsion. The detection limits of dimethylarsinate, monomethylarsonate, and inorganic arsenic in solid matrices were 0.12, 0.26, and 1.1 mg/kg, respectively. The optimized method was sensitive, convenient, and reliable for the extraction and analysis of different arsenic species in solid samples.

  1. 叔丁醇细菌内毒素检查方法的建立%Establishment of Bacterial Endotoxins Test for Tertiary Butyl Alcohol

    Institute of Scientific and Technical Information of China (English)

    于海洲; 都婧; 于风平

    2015-01-01

    目的:建立叔丁醇细菌内毒素检查方法。方法:采用2个不同厂家的鲎试剂和3批样品,进行预干扰试验和干扰试验。结果:供试品溶液对鲎试剂与细菌内毒素之间的凝集反应无干扰;样品的细菌内毒素限值确定为0.25 EU·ml-1。结论:所建立的方法可行,可用于叔丁醇的细菌内毒素检查。%Objective:To establish a method for the detection of bacterial endotoxins in tertiary butyl alcohol. Methods:The in-terference experiment and bacterial endotoxins test for 3 batches of the products from 2 companies were carried out with tachypleus ame-bocyte lysate. Results:There was no interference in the bacterial endotoxins test. The limit of bacterial endotoxins was 0. 25 EU/ml. Conclusion:The established method of bacterial endotoxins test is feasible for tertiary butyl alcohol.

  2. Interplay between pro-inflammatory cytokines and brain oxidative stress biomarkers: evidence of parallels between butyl paraben intoxication and the valproic acid brain physiopathology in autism rat model.

    Science.gov (United States)

    Hegazy, Hoda G; Ali, Elham H A; Elgoly, Amany H Mahmoud

    2015-02-01

    Butyl paraben is a preservative used in food, drugs and cosmetics. Neurotoxic effect was reported recently beside the potential estrogenic activity of parabens. There is controversy as to the potential harmful effects of butyl parabens, which are suspected to contribute to autism and learning disabilities. The purpose of this study was to examine the similarities between paraben intoxication signs in the rat brain and brain markers in an autistic like rat model. This study provides evidence of many parallels between the two, including (1) oxidative stress, (2) decreased reduced glutathione levels and elevated oxidised glutathione, (3) mitochondrial dysfunction, and (4) neuroinflammation and increased pro-inflammatory cytokine levels in the brain (tumour necrosis factor-alpha, interleukin-1-beta, and interleukin-6). (5) Increased protein oxidation reported by a significant increase in 3-nitrotyrosine (3-NT)/tyrosine ratio. (6) A marked disturbance was found in the production of energy carriers (AMP, ATP and AMP/ATP ratio) in comparison with the control. The evidence suggests that paraben may, to some extent, either cause or contribute to the brain physiopathology in ASDs or pathogens that produce the brain pathology observed in the diagnosed rat model of ASD.

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

    DEFF Research Database (Denmark)

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

    1995-01-01

    UV spectra and kinetics for the reactions of alkyl and alkylperoxy radicals from methyl tert-butyl ether (MTBE) were studied in 1 atm of SF6 by the pulse radiolysis-UV absorption technique. UV spectra for the radical mixtures were quantified from 215 to 340 nm. At 240 nm, sigma(R) = (2.6 +/- 0.4) X...... 10(-18) cm(2) molecule(-1) and sigma(RO2) = (4.1 +/- 0.6) X 10(-18) cm(2) molecule(-1) (base e). The rate constant for the self-reaction of the alkyl radicals is (2.5 +/- 1.1) X 10(-11) cm(3) molecule(-1) s(-1). The rate constants for reaction of the alkyl radicals with molecular oxygen...... and the alkylperoxy radicals with NO and NO2 are (9.1 +/- 1.5) X 10(-13), (4.3 +/- 1.6) X 10(-12) and (1.2 +/- 0.3) X 10(-11) cm(3) molecule(-1) s(-1), respectively. The rate constants given above refer to reaction at the tert-butyl side of the molecule....

  4. 1,4-丁炔二醇汽提塔塔顶节能改造%Energy efficiency innovation of tower top of butyl alkynyl glycol stripper

    Institute of Scientific and Technical Information of China (English)

    张明辉; 刘静

    2011-01-01

    About 350 kPa saturated vapor is discharged from the tower top of butyl alkynyl glycol stripper to condenser,in which will be heated exchange with circulating water,this will consume lots of latent heat.Withal,added waste heat boiler to the top of butyl alkynyl glycol stripper,which can make use of latent heat contained in top vapour to get secondary steam and save the consume of energy,and achieve the win-win-win of economic benefit,environmental protection benfit,and safety benefit.%1,4-丁炔二醇汽提塔塔顶气相为350 kPa左右的饱和蒸汽,直接进入冷凝器与循环水进行热交换,浪费了其中大量的潜热。通过在1,4-丁炔二醇汽提塔塔顶增加废热锅炉,使塔顶蒸汽中所含有的潜热得到了充分的利用,生成了二次蒸汽,节约了能源,达到经济效益、环保效益、安全效益三赢的目的。

  5. Quantitative structure-property relationship modeling of water-to-wet butyl acetate partition coefficient of 76 organic solutes using multiple linear regression and artificial neural network.

    Science.gov (United States)

    Dashtbozorgi, Zahra; Golmohammadi, Hassan

    2010-12-01

    The main aim of this study was the development of a quantitative structure-property relationship method using an artificial neural network (ANN) for predicting the water-to-wet butyl acetate partition coefficients of organic solutes. As a first step, a genetic algorithm-multiple linear regression model was developed; the descriptors appearing in this model were considered as inputs for the ANN. These descriptors are principal moment of inertia C (I(C)), area-weighted surface charge of hydrogen-bonding donor atoms (HACA-2), Kier and Hall index (order 2) ((2)χ), Balaban index (J), minimum bond order of a C atom (P(C)) and relative negative-charged SA (RNCS). Then a 6-4-1 neural network was generated for the prediction of water-to-wet butyl acetate partition coefficients of 76 organic solutes. By comparing the results obtained from multiple linear regression and ANN models, it can be seen that statistical parameters (Fisher ratio, correlation coefficient and standard error) of the ANN model are better than that regression model, which indicates that nonlinear model can simulate the relationship between the structural descriptors and the partition coefficients of the investigated molecules more accurately.

  6. Theoretical Study on Gas—phase Pyrolytic Reactions of N—Ethyl,Isopropyl and N—t—Butyl Substituted 2—Aminopyrazine

    Institute of Scientific and Technical Information of China (English)

    洪三国; 陈丽萍

    2003-01-01

    Density functional theory(DFT)and ab initio methods were used to study gas-phase pyrolytic reaction mechanisms of N-ethyl,N-isopropyl and N-t-butyl substituted 2-aminopyrazine at B3LYP/6-31G* and MP2/6-31G*,respectively,Single-point energies of all optimized molecular geometries were calculated at B3LYP/6-311 G(2d,p)level.Results show that the pyrolytic reactions which were caused by the migration of atom H(17) via a six-member ring transiton state.The activation energies which were verified by vibrational analysis and correlated with zero-point energies along the reaction channel atB3LYP/6-3110 G(2d,p)level were 252.02kJ·mol-1(N-ethyl substituted),235.92kJ·mol-1(N-isopropyl substituted)and 234.27kJ·mol-1(N-t-butyl substituted),respectively.The results were in good agreement with available experimental data.

  7. Insights into the mechanism of extraction of uranium (VI) from nitric acid solution into an ionic liquid by using tri-n-butyl phosphate.

    Science.gov (United States)

    Gaillard, Dr Clotilde; Boltoeva, Maria; Billard, Isabelle; Georg, Sylvia; Mazan, Valérie; Ouadi, Ali; Ternova, Dariia; Hennig, Christoph

    2015-08-24

    We present new results on the liquid-liquid extraction of uranium (VI) from a nitric acid aqueous phase into a tri-n-butyl phosphate/1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (TBP/[C4 mim][Tf2 N]) phase. The individual solubilities of the ionic-liquid ions in the upper part of the biphasic system are measured over the whole acidic range and as a function of the TBP concentration. New insights into the extraction mechanism are obtained through the in situ characterization of the extracted uranyl complexes by coupling UV/Vis and extended X-ray absorption fine structure (EXAFS) spectroscopy. We propose a chemical model to explain uranium (VI) extraction that describes the data through a fit of the uranyl distribution ratio DU . In this model, at low acid concentrations uranium (VI) is extracted as the cationic complex [UO2 (TBP)2 ](2+) , by an exchange with one proton and one C4 mim(+) . At high acid concentrations, the extraction proceeds through a cationic exchange between [UO2 (NO3 )(HNO3 )(TBP)2 ](+) and one C4 mim(+) . As a consequence of this mechanism, the variation of DU as a function of TBP concentration depends on the C4 mim(+) concentration in the aqueous phase. This explains why noninteger values are often derived by analysis of DU versus [TBP] plots to determine the number of TBP molecules involved in the extraction of uranyl in an ionic-liquid phase.

  8. Synthesis of n-Butyl Salicylate Catalyzed by Sodium Bisulfate%硫酸氢钠催化合成水杨酸正丁酯

    Institute of Scientific and Technical Information of China (English)

    吴春燕

    2015-01-01

    Butyl salicylate was synthesized from salicylic acid and n-butanol catalyzed by sodium bisulfate.The effect of the molar ratio of n-butanol to salicylic acid,the reaction time,the amount of catalyst was discussed. Optimal conditions were obtained:the molar ratio of n-butanol to salicylic acid was 1.6:1, the reaction time was 4h and the mass ratio of catalyst to salicylic acid was 6%, the yield of butyl salicylate was 60.66%.%以水杨酸和正丁醇为原料,硫酸氢钠为催化剂,合成了水杨酸正丁酯。考察了正丁醇与水杨酸摩尔比、反应时间、催化剂用量对酯化收率的影响。通过实验得到最佳工艺条件为:正丁醇与水杨酸摩尔比为1.6∶1,反应时间为4h,催化剂用量为水杨酸用量的6%(质量分数),水杨酸正丁酯收率可达60.66%。

  9. Reaction of Ketene Dithioacetals with Pyrazolylcarbohydrazide:Synthesis and Biological Activities of Ethyl 5-Amino-1-(5'-methyl-1'-t-butyl-4'-pyrazolyl)carbonyl-3-methylthio-1H-pyrazole-4-carboxylate

    Institute of Scientific and Technical Information of China (English)

    LI Ming李明; WEN Li-Rong文丽荣; FU Wei-Jun付维军; ZHAO Gui-Long赵桂龙; HU Fang-Zhong胡方中; YANG Hua-Zheng杨华铮

    2004-01-01

    The title compound, C16-H23N5O3S, ethyl 5-amino-1-(5'-methyl-1'-t-butyl-4'-pyrazolyl)carbonyl-3-methylthio1H-pyrazole-4-carboxylate (5) has been synthesized by the treatment of ethyl 2-cyano-3,3-dimethylthioacrylate with 1-t-butyl-5-methyl-4-hydrazinocarbonylpyrazole (4) in refluxed ethanol. The possible mechanism of the above reaction was also discussed. The results of biological test show that the title compound has fungicidal and plant growth regulation activities.

  10. EXPERIMENTAL STUDY ON DEGRADATION OF BUTYL XANTHATE IN WATER BY UV/O3%UV/O3处理丁基黄药废水

    Institute of Scientific and Technical Information of China (English)

    张萌; 柳建设

    2011-01-01

    采用UV/O3氧化法处理丁基黄药溶液,考察了丁基黄药质量浓度、溶液pH对丁基黄药降解率的影响.研究结果表明,初始pH增大有利于丁基黄药的降解,在25℃,pH=1 1.36,光照强度为36W,臭氧浓度为7.32 mg·L-1,丁基黄药初始质量浓度为100 mg· L-1时,经10 min后丁基黄药去除率达到99%以上.在UV/O3联合作用下,丁基黄药的降解基本上满足准1级反应动力学规律,反应20 min后,COD与TOC去除率仅为33.9%与14.5%左右,这表明UV/O3不能使丁基黄药完全矿化,只能生成一系列中间产物.%The wastewater containing butyl xanthate was treated by UV/O3, and the effect of pH value and initial concentration were discussed." The experimental results showed that when initial concentration was 100 mg·L-1, pH value was 11.36 and ozone concentration was 7.32 mg·L-1, the removal efficiency could reach 99% within 10 min. The degradation of butyl xanthate by UV/O3 satisfied basically the rule of pseudo-first order reaction kinetics. The removal rate of COD and TOC were 33.9% and 14.5%. The results showed that UV/O3 could not mineralize butyl xanthate completely, and a series of intermediate products were produced.

  11. Preparation, Characterization of Dawson-type Heteropoly Acid Cerium (Ⅲ) Salt and Its Catalytic Performance on the Synthesis of n-Butyl Acetate

    Institute of Scientific and Technical Information of China (English)

    CAO Xiaohua; REN Jie; XU Changlong; ZHANG Kanghua; ZHAN Changchao; LAN Jian

    2013-01-01

    A novel cerium (Ⅲ) salt of Dawson type tungstophosphoric acid (Ce2P2W18O62·16H2O) was prepared by doping cerous nitrate in H6P2W18O62.13H2O powder and characterized by thermogravimetry and differential thermal analyses (TG/DTA),Fourier transform infrared spectroscopy (FT-IR),X-ray powder diffraction (XRD),pyridine infrared spectroscopy (Py-IR) and scanning electron microscopy (SEM).Its catalytic activity was evaluated by the probe reaction of synthesis of n-butyl acetate with acetic acid and n-butanol.The effects of various parameters such as molar ratio of n-butanol to acetic acid,reaction temperature,reaction time,and catalyst amount have been studied by single factor experiment.The results show that Ce2P2W18O62·16H2O behaved as an excellent heterogeneous catalyst in the synthesis of n-butyl acetate.The optimum synthetic conditions were determined as follows:molar ratio of n-butanol to acetic acid at 2.0 ∶ 1.0,mass of the catalyst being 1.44% of the total reaction mixture,reaction temperature of 120 ℃ and reaction time of 150 min.Under above conditions,the conversion of acetic acid was above 97.8 %.The selectivity of n-butyl acetate based on acetic acid was,in all cases,nearly 100%.The catalysts could be recycled and still exhibited high catalytic activity with 90.4% conversion after five cycles of reaction.It was found by means of TG-DTA and Py-IR that the catalyst deactivation was due to the adsorption of a complex of by-product on the active sites on catalysts surface or the catalyst loss in its separation from the products.Compared with using sulfuric acid as catalyst,the present procedure with Ce2P2W18O62· 16H2O is a green productive technology due to simple process,higher yield,catalyst recycling and no corrosion for the production facilities.

  12. Me-OMS-1s分子筛催化叔丁基过氧化氢分解制备叔丁醇%Catalytic decomposition oftert-butyl hydroperoxide intotert-butyl alcohol over Me-OMS-1s molecular sieves

    Institute of Scientific and Technical Information of China (English)

    冯利利; 卢书培; 齐兴义; 韩晓

    2015-01-01

    A series of Me-OMS-1s (Me=Mg, Co, Ni, Cu) molecular sieves wassynthesized by the static hydrothermal method. The as-synthesized Me-OMS-1s were characterized by means of XRD and AES-ICP. The effects of reaction temperature (318—338 K), reaction time (0.5—6 h) and formal catalyst concentration (1.67—8.33 mg·ml−1) were investigated in detail on catalytic decomposition of tert-butyl hydroperoxide intotert-butyl alcohol over the as-synthesized Me-OMS-1s. The results showed that the synthetic Me-OMS-1s belonged to todorokite-type manganese oxides. All the Me-OMS-1 catalysts bore the activity for the catalytic disproportionation decomposition oftert-butyl hydroperoxide under the selected heterogeneous catalytic reaction conditions. The conversion of the reactanttert-butyl hydroperoxide under various reaction conditions was found to be high and the selectivity towards the producttert-butyl alcohol was 100%. The activity of Me-OMS-1s followed the order of: Cu-OMS-1 > Mg-OMS-1 > Ni-OMS-1 > Co-OMS-1. The conversion level oftert-butyl hydroperoxide was markedly enhanced with increasing reaction temperature, contact time and formal Me-OMS-1 concentration.%采用静态水热法合成了Me-OMS-1s(Me=Mg,Co,Ni,Cu)分子筛催化剂,对合成的分子筛进行了X射线衍射和电感耦合等离子体发射光谱表征,并系统考察了反应温度(318~338 K)、反应时间(0.5~6 h)和催化剂用量(1.67~8.33 mg·ml−1)对Me-OMS-1s催化叔丁基过氧化氢分解制备叔丁醇反应性能的影响。研究结果表明,合成的分子筛均为钡镁锰矿型(todorokite)氧化锰;在选择的多相催化反应条件下,Me-OMS-1s均有催化叔丁基过氧化氢歧化分解的反应活性,反应物叔丁基过氧化氢具有较高的转化率,产物叔丁醇的选择性均为100%。Me-OMS-1s催化叔丁基过氧化氢歧化分解的反应活性顺序为:Cu-OMS-1> Mg-OMS-1> Ni-OMS-1> Co-OMS-1。叔丁基过氧化氢的转

  13. Exploration of the molecular architecture of the orthosteric binding site in the α4β2 nicotinic acetylcholine receptor with analogs of 3-(dimethylamino)butyl dimethylcarbamate (DMABC) and 1-(pyridin-3-yl)-1,4-diazepane

    DEFF Research Database (Denmark)

    Bach, Tinna Brøbech; Jensen, Anders A.; Petersen, Jette G.;

    2015-01-01

    and protrudes along the interfacial cleft between subunits. To probe these putative extensions in functional nicotinic acetylcholine receptors (nAChRs), elongated analogs of 3-(dimethylamino)butyl dimethylcarbamate (DMABC) and 1-(pyridine-3-yl)-1,4-diazepane were prepared and characterized pharmacologically...

  14. Living/controlled free radical copolymerization of chlorotrifluoroethene and butyl vinyl ether under 60Co γ-ray irradiation in the presence of S-benzyl O-ethyl dithiocarbonate.

    Science.gov (United States)

    Liu, Lei; Lu, Dan; Wang, Hu; Dong, Qibao; Wang, Pucheng; Bai, Ruke

    2011-07-21

    Living/controlled free radical copolymerization of chlorotrifluoroethene and butyl vinyl ether has been successfully achieved at room temperature under (60)Co γ-ray irradiation in the presence of S-benzyl O-ethyl dithiocarbonate. The alternating and block copolymers have been obtained with well-defined molecular weights and narrow molecular weight distributions.

  15. Structural characterisation of degradation products formed upon di-n-butyl phthalate radiolysis by high-performance liquid chromatography electro-spray tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tintaru, A.; Charles, L. [Univ Aix Marseille 1, CNRS, Lab Chim Provence Spectrometries Appl Chim Struct, UMR 6264, F-13397 Marseille (France); Univ Aix Marseille 2, CNRS, Lab Chim Provence Spectrometries Appl Chim Struct, UMR 6264, F-13397 Marseille (France); Labed, V. [CEA Marcoule, DTCD SPDE L2ED, F-30207 Bagnols Sur Ceze (France)

    2010-07-01

    Complete text of publication follows: Structural characterisation of 15 degradation products, formed upon di-n-butyl phthalate (DBP) radiolysis, has been achieved using a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) coupling. The dissociation behaviour of protonated DBP was first established to be further used to characterise structural deviation in the degradation products. Based on accurate mass measurements, compounds shown by HPLC-MS analysis were all found to be DBP oxidation products, amongst which various sets of isomers could be distinguished. Collision-induced dissociation experiments performed on each electro-sprayed molecule first allowed unambiguous definition of the location of the additional oxygen atoms; that is, in the alkyl branch or on the aromatic ring. Although location of the oxygen atom in the alkyl branches could not always be precisely determined, relative abundances of some product ions allowed oxygenated functions to be identified

  16. Evaluation of the toxicity of onyx compared with n-butyl 2-cyanoacrylate in the subarachnoid space of a rabbit model: an experimental research

    Energy Technology Data Exchange (ETDEWEB)

    Bakar, Bulent [Kirikkale University, School of Medicine, Department of Neurosurgery, Kirikkale (Turkey); Kirikkale University Faculty of Medicine, Department of Neurosurgery, Kirikkale (Turkey); Oruckaptan, Hakan H.; Hazer, Burcu D. [Hacettepe University, School of Medicine, Department of Neurosurgery, Ankara (Turkey); Saatci, Isil [Hacettepe University, School of Medicine, Department of Radiology, Ankara (Turkey); Atilla, Pergin; Muftuoglu, Sevda F. [Hacettepe University, School of Medicine, Department of Histology and Embriology, Ankara (Turkey); Kilic, Kamer [Hacettepe University, School of Medicine, Department of Biochemistry, Ankara (Turkey)

    2010-02-15

    The toxic effects of onyx, its solvent dimethyl sulphoxide (DMSO), and n-butyl 2-cyanoacrylate (NBCA) were evaluated after infusion into the subaracnoid space of a rabbit model. Each of the two various concentrations of onyx, pure DMSO, NBCA, and normal saline solution were percutaneously infused into the pontocerebellar cisternae of 39 domestic male albino rabbits, after which, the brain stems and medial cerebellar tissues were harvested for biochemical and histopathological studies. The specimens infused in various concentration of onyx, DMSO, and NBCA showed neural tissue necrosis and edema with inflammatory cell infiltration in the acute stage. Although the mean values of the lipid peroxidase in the control, saline, and NBCA groups were found to be almost similar, they were found to be low in the onyx and DMSO groups. This experimental study suggests that NBCA, and various concentrations of onyx and DMSO have toxic effects on the neural tissues of rabbits when infused into the subarachnoid space. (orig.)

  17. Measurement and modelization of VLE of binary mixtures of propyl acetate, butyl acetate or isobutyl acetate with methanol at pressure of 0.6 MPa

    Institute of Scientific and Technical Information of China (English)

    P Susial; D Garca; R Susial; YC Clavijo; A Martn

    2016-01-01

    The vapor–liquid equilibrium of binary mixtures of propyl acetate, butyl acetate and isobutyl acetate with meth-anol has been determined at a constant pressure of 0.6 MPa. Results have been modeled with the Peng–Robinson equation, a traditional cubic equation of state widely employed in chemical industries, as well as with the perturbed-chain statistical associating fluid PC-SAFT theory of Gross–Sadowski. By correlation of the binary inter-action parameters of these equations, the measured vapor–liquid equilibrium data can be accurately predicted. Thus, this work shows that these models are able to represent the experimental data for systems with associating compounds via hydrogen bonding.

  18. 6-Butyl-5-(4-methylphenoxy-3-phenyl-3H-1,2,3-triazolo[4,5-d]pyrimidin-7(6H-one

    Directory of Open Access Journals (Sweden)

    Hong-Mei Wang

    2010-11-01

    Full Text Available In the title compound, C21H21N5O2, the triazolopyrimidine ring system is essentially planar [maximum displacement = 0.021 (4 Å] and forms dihedral angles of 41.17 (9 and 67.99 (8° with the phenyl and benzene rings, respectively. The n-butyl side chains is disordered over two positions with an ccupancy ratio of 0.77:0.23. An intramolecular C—H...O hydrogen-bonding interaction stabilizes the molecular conformation. In the crystal, molecules are linked by intermolecular C—H...O and C—H...N hydrogen bonds into a three-dimensional network. In addition, π–π stacking interactions involving the triazole and pyrimidine rings of adjacent molecules are observed, with centroid–centroid distances of 3.545 (1 Å.

  19. Bis(N-sec-butyl-N-n-propyldithiocarbamato-κ2S,S′(1,10-phenanthroline-κ2N,N′zinc(II

    Directory of Open Access Journals (Sweden)

    Amna Salem Alzaalouk

    2010-09-01

    Full Text Available Two independent but very similar molecules comprise the asymmetric unit of the title compound, [Zn(C8H16NS22(C12H8N2]. The N2S4 donor set about Zn is defined by two symmetrically chelating dithiocarbamate ligands and a 1,10-phenanthroline ligand. Distortions from the ideal octahedral coordination geometry arise from the restricted bite angles of the ligands. The main feature of the crystal packing is the formation of tetrameric supramolecular aggregates mediated by C—H...S interactions. Disorder was found in each of the sec-butyl groups. This was resolved over two positions in each case with the major components of the disorder having site occupancies in the range 0.551 (6–0.725 (5.

  20. Molecular dynamics and residual entropy in the soft crystal, SmE phase, of 4-butyl-4'-isothiocyano-1,1'-biphenyl.

    Science.gov (United States)

    Ishimaru, Shin'ichi; Saito, Kazuya; Ikeuchi, Satoaki; Massalska-Arodz, Maria; Witko, Waclaw

    2005-05-26

    Molecular dynamics and resulting disorder in the soft crystal, smectic E (SmE) phase, were studied in detail for the title compound, 4-butyl-4'-isothiocyano-1,1'-biphenyl (4TCB), by (1)H NMR spectroscopy and adiabatic calorimetry. The ordered crystal phase of 4TCB was realized for the first time under ambient pressure after long two-step annealing and used as the reference state in the analysis of the experimental results. Four motional modes were identified in the SmE phase through the analysis of the (1)H NMR T(1). The residual entropy was determined as ca. 6 J K(-1) mol(-1). This magnitude implies that most of the disorder in the SmE phase at high temperatures is removed on cooling except for the head-to-tail disorder of the rod-shaped 4TCB molecule. Standard thermodynamic functions are tabulated below 375 K.

  1. Microwave-assisted synthesis of sec/tert-butyl 2-arylbenzimidazoles and their unexpected antiproliferative activity towards ER negative breast cancer cells.

    Science.gov (United States)

    Abdul Rahim, Aisyah Saad; Salhimi, Salizawati Muhamad; Arumugam, Natarajan; Pin, Lim Chung; Yee, Ng Shy; Muttiah, Nithya Niranjini; Keat, Wong Boon; Abd Hamid, Shafida; Osman, Hasnah; Mat, Ishak b

    2013-12-01

    A new series of N-sec/tert-butyl 2-arylbenzimidazole derivatives was synthesised in 85-96% yields within 2-3.5 min by condensing ethyl 3-amino-4-butylamino benzoate with various substituted metabisulfite adducts of benzaldehyde under focused microwave irradiation. The benzimidazole analogues were characterised using (1)H NMR, (13)C NMR, high resolution MS and melting points. Evaluation of antiproliferative activity of the benzimidazole analogues against MCF-7 and MDA-MB-231 revealed several compounds with unexpected selective inhibitions of MDA-MB-231 in micromolar range. All analogues were found inactive towards MCF-7. The most potent inhibition against MDA-MB-231 human breast cancer cell line came from the unsubstituted 2-phenylbenzimidazole 10a.

  2. 氨基磺酸催化合成脂肪酸丁酯的研究%Synthesis of fatty acid butyl ester catalyzed by amino sulfonic acid

    Institute of Scientific and Technical Information of China (English)

    程正载; 龚凯; 张卫星; 高松; 雷锐; 颜晓潮; 从野

    2014-01-01

    The fatty acid butyl ester was respectively synthesized by the esterification of oleic acid with bu-tanol and the transesterification of rapeseed oil with butanol catalyzed by amino sulfonic acid. The fatty acid butyl ester product was analyzed by GC and its structure was characterized by FT-IR. The effects of molar ratio of butanol to oil ( oleic acid or rapeseed oil) , catalyst dosage, reaction temperature and reac-tion time on the conversion rates of oleic acid and rapeseed oil were investigated. The results showed that the optimal esterification conditions were obtained as follows: molar ratio of butanol to oleic acid 3∶1 , catalyst dosage 0. 8% (based on the mass of oleic acid), reaction temperature 110℃and reaction time 1. 5 h. Under these conditions, the conversion rate of oleic acid and the yield of fatty acid butyl ester reached 88. 6% and 83. 5%, respectively. The optimal transesterification conditions were obtained as follows:molar ratio of butanol to rapeseed oil 10∶1, catalyst dosage 1. 0% (based on the mass of rapeseed oil), reaction temperature 115℃ and reaction time 2. 0 h. Under the optimal conditions, the conversion rate of rapeseed oil and the yield of fatty acid butyl ester achieved 85. 6% and 80. 1%, respectively.%以氨基磺酸为催化剂,油酸及菜籽油与正丁醇分别进行酯化反应与酯交换反应制备脂肪酸丁酯。并利用气相色谱及红外光谱对产物进行分析及结构表征。考察了醇(正丁醇)油(油酸及菜籽油)摩尔比、催化剂用量、反应温度和反应时间对油酸及菜籽油转化率的影响。结果表明,油酸酯化反应的最佳工艺条件为:醇油摩尔比3∶1,催化剂用量为油酸质量的0.8%,反应温度110℃,反应时间1.5 h,此时油酸转化率达到88.6%,产品收率为83.5%;菜籽油酯交换反应的最佳工艺条件为:醇油摩尔比10∶1,催化剂用量为菜籽油质量的1.0%,反应温度115℃,反应时间2.0 h,

  3. Isolation and identification of N-butyl-tetrahydro-5-oxofuran-2-carboxamide produced by Bacillus sp. L60 and its antifungal activity.

    Science.gov (United States)

    Lee, Yong-Seong; Cho, Jeong-Yong; Moon, Jae-Hak; Kim, Kil-Yong

    2017-03-01

    Rhizoctonia solani is the cause of substantial economic loss in many crops. The aim of this study is to investigate biocontrol potential of Bacillus sp. L60 against R. solani and to purify an antifungal compound. In this study, Bacillus sp. L60 demonstrated significant antagonism toward R. solani with the dual culture assay. The antifungal compound was extracted from Bacillus sp. L60 culture supernatant with n-butanol, and identified as N-butyl-tetrahydro-5-oxofuran-2-carboxamide (BT-5O-2C) having molecular weights of 185.1052 Da with the formula C9 H15 NO3 using NMR and HR-ESI-MS analysis. The minimum inhibitory concentration (MIC) value of the antifungal compound was 256 µg ml(-1) against R. solani. Therefore, our results clearly demonstrated BT-5O-2C as well as Bacillus sp. L60 as potential biological control agents for the management of R. solani.

  4. Interaction between amphiphilic ionic liquid 1-butyl-3-methylimidazolium octyl sulfate and anionic polymer of sodium polystyrene sulfonate in aqueous medium

    Science.gov (United States)

    Barhoumi, Z.; Saini, M.; Amdouni, N.; Pal, A.

    2016-09-01

    The micellization of an aqueous solution of the surface active ionic liquid (SAIL), 1-butyl-3-methylimidazolium octylsufate (C4mim)(C8OSO3) and its interaction with an anionic polymer sodium polystyrene sulfonate, (NaPSS) were studied using conductimetry, tensiometry and fluorimetry. Surface tension profile shows a more dramatic increase in the value of surface tension of aqueous (C4mim)(C8OSO3) before the critical micelle concentration (cmc) of IL. The critical micelle concentration (cmc) value of this surfactant was found out from conductance measurements. The thermodynamic parameters, i.e., Gibb's free energy, enthalpy, and entropy of micellization of the IL in aqueous solution have been calculated. Behavior of fluorescence probe confirms the binding interactions between SAIL and the polyelectrolyte.

  5. Environmental Fate of the Herbicide Fluazifop-P-butyl and Its Degradation Products in Two Loamy Agricultural Soils: A Combined Laboratory and Field Study

    DEFF Research Database (Denmark)

    Badawi, Nora; Rosenbom, Anette E.; Olsen, Preben;

    2015-01-01

    The herbicide fluazifop-P-butyl (FPB) is used against grasses in agricultural crops such as potato, oilseed rape and sugar beet. Limited information is available in Scientific literature on its environmental fate, therefore extensive monitoring at two agricultural test fields was combined...... with laboratory studies to determine leaching and the underlying degradation and sorption processes. Water samples from drains, suction cups, and groundwater wells showed leaching of the degradation products fluazifop-P (FP) and 2- hydroxy-5-trifluoromethyl-pyridin (TFMP) following FPB treatment. Laboratory...... experiments with soil from each field revealed a rapid degradation of FPB to FP. The degradation was almost exclusively microbial, and further biodegradation to TFMP occurred at a slower rate. Both degradation products were sorbed to the two soils to a small extent and were fairly persistent to degradation...

  6. Radiation-induced copolymerization of styrene/ n-butyl acrylate in the presence of ultra-fine powdered styrene-butadiene rubber

    Science.gov (United States)

    Yu, Haibo; Peng, Jing; Zhai, Maolin; Li, Jiuqiang; Wei, Genshuan; Qiao, Jinliang

    2007-11-01

    Styrene (St)/ n-butyl acrylate (BA) copolymers were prepared by two-stage polymerization: St/BA was pre-polymerized to a viscous state by bulk polymerization with initiation by benzoyl peroxide (BPO) followed by 60Co γ-ray radiation curing. The resultant copolymers had higher molecular weight and narrower molecular weight distribution than conventional methods. After incorporation of ultra-fine powdered styrene-butadiene rubber (UFSBR) with a particle size of 100 nm in the monomer, the glass transition temperature ( Tg) of St-BA copolymer increased at low rubber content. Both the St-BA copolymer and the St-BA copolymer/UFSBR composites had good transparency at BA content below 40%.

  7. Copolymerization of 1-hexene and 1-dodecene with 1,3-butadiene by a versatate/diisobutylaluminum hydride/t-butyl chloride catalyst system

    Directory of Open Access Journals (Sweden)

    Gustavo Monteiro da Silva

    2014-01-01

    Full Text Available The aim of this study was to incorporate an alpha-olefin (1-hexene or 1-dodecene in a high cis polybutadiene chain, using a neodymium versatate/diisobutylaluminum hydride/t-butyl chloride catalyst system. The influence of alpha-olefin on polymerization reaction and polymer characteristics, using different weight ratios of butadiene/α-olefin, was evaluated. The copolymers were characterized by SEC, FTIR, NMR, TGA and viscosimetric analysis. The thermal stability of the polymer tended to increase with incorporation of alpha-olefins, while its microstructure was not affected. The weight average molecular mass (Mw tended to increase and the polymerization conversion tended to decrease with increasing alpha-olefins content. The copolymers showed a lower intrinsic viscosity than for the homopolymer. The results indicated that the alpha-olefins were incorporated in the polybutadiene chain.

  8. Application of the Bahe's pseudolattice-theory to water-1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)) mixtures at 298.15K Part I. Autoprotolysis constants.

    Science.gov (United States)

    Bou Malham, I; Letellier, P; Turmine, M

    2007-04-15

    The autoprotolysis constants (K(s)) of water - 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)) mixtures were determined at 298K over the composition range of 0 to 77.43vol.% bmimBF(4) using potentiometric method with a glass electrode. A slight increase in the autoprotolysis constant was observed when the salt was added to the water. The value of the ionic product of the medium then decreases as the bmimBF(4) content increases from about 20vol.%. The acid-base properties of these media were perfectly described by Bahe's approaches that were completed by Varela et al. concerning structured electrolyte solutions with large short-range interactions.

  9. Molten solvent extraction behavior of trivalent La, Sm, Dy, and Yb withtri-n-butyl phosphate into molten paraffin wax at 60 ℃

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The extraction behavior of La3+, Sm3+, Dy3+, and Yb3+ in sodium acetate-acetic acid medium was studied with tri-n-butyl phosphate (TBP) at 60 ℃ using paraffin wax as a diluent. The extraction percentage is greater than 85% in the pH range of 6 to 8. The result of slope analysis method indicates that the compositions of the extracted species are different between the light and heavy rare earths. The formula of the extracted species is found to be La(TBP)(OH)(Ac)2for La3+ and Yb(TBP)(OH)3 for Yb3+. The effects of extracting time, the concentration of TBP in the organic phase and salts on the extraction efficiency were also discussed.

  10. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid

    Directory of Open Access Journals (Sweden)

    Hongzhu Liu

    2017-01-01

    Full Text Available Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE, vinyl acetate (VAc, n-butyl acrylate (BA, Veova 10, and acrylic acid (AA. The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  11. Poly[μ2-aqua-aqua[μ3-N-butyl-N-(2-hydroxyethyldithiocarbamato-κ3O,O′:S]sodium

    Directory of Open Access Journals (Sweden)

    Muzzaffar A. Bhat

    2016-02-01

    Full Text Available In the title compound, [Na(C7H14NOS2(H2O2]n, the NaI cation is coordinated by five O atoms [Na—O = 2.3142 (11–2.4677 (10 Å] from three aqua and two N-butyl-N-(2-hydroxyethyldithiocarbamate (L ligands and one S atom [Na—S = 3.0074 (6 Å] from a third L ligand in a highly distorted octahedral geometry. Two aqua ligands related by an inversion center bridge two NaI cations, and each L ligand coordinates three NaI cations, leading to a layered arrangement aligned parallel to the bc plane. Intermolecular O—H...S hydrogen bonds are observed in the inner part of each polymeric layer; these are packed along the a axis and held together by weak van der Waals forces.

  12. Poly[[[diisothiocyanatocobalt(II]-bis[μ-4-tert-butyl-2,6-bis(1,2,4-triazol-1-ylmethylphenol

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available In the title compound, {[Co(NCS2(C16H20N6O2]·2C3H7NO·2H2O}n, each CoII ion located on an inversion center is six-coordinated by four equatorial N atoms from four different 4-tert-butyl-2,6-bis(1,2,4-triazol-1-ylmethylphenol (L ligands, and by two N atoms from two axial thiocyanate anions [Co—N = 2.104 (3–2.144 (3 Å]. The metal centres are connected via the bidentate L ligands into two-dimensional polymeric layers parallel to bc plane. The dimethylformamide and solvent water molecules participate in intermolecular O—H...O and O—H...S hydrogen bonds, which consolidate the crystal packing.

  13. Encapsulated Ionic Liquids for CO2 Capture: Using 1-Butyl-methylimidazolium Acetate for Quick and Reversible CO2 Chemical Absorption.

    Science.gov (United States)

    Moya, Cristian; Alonso-Morales, Noelia; Gilarranz, Miguel A; Rodriguez, Juan J; Palomar, Jose

    2016-12-05

    The potential advantages of applying encapsulated ionic liquid (ENIL) to CO2 capture by chemical absorption with 1-butyl-3-methylimidazolium acetate [bmim][acetate] are evaluated. The [bmim][acetate]-ENIL is a particle material with solid appearance and 70 % w/w in ionic liquid (IL). The performance of this material as CO2 sorbent was evaluated by gravimetric and fixed-bed sorption experiments at different temperatures and CO2 partial pressures. ENIL maintains the favourable thermodynamic properties of the neat IL regarding CO2 absorption. Remarkably, a drastic increase of CO2 sorption rates was achieved using ENIL, related to much higher contact area after discretization. In addition, experiments demonstrate reversibility of the chemical reaction and the efficient ENIL regeneration, mainly hindered by the unfavourable transport properties. The common drawback of ILs as CO2 chemical absorbents (low absorption rate and difficulties in solvent regeneration) are overcome by using ENIL systems.

  14. Speciation of mercury in human whole blood by capillary gas chromatography with a microwave-induced plasma emission detector system following complexometric extraction and butylation.

    Science.gov (United States)

    Bulska, E; Emteborg, H; Baxter, D C; Frech, W; Ellingsen, D; Thomassen, Y

    1992-03-01

    Methyl- and inorganic mercury were extracted from human whole blood samples, as their diethyldithiocarbamate complexes, into toluene and butylated by using a Grignard reagent. The mercury species were then separated by gas chromatography (on a 12 m non-polar DB-1 capillary column) and detected by a microwave-induced plasma atomic emission spectrometric (GC-MPD) system. The accuracy and precision of the proposed method were established by the analysis of Seronorm lyophilized human whole blood standards for methyl- and inorganic mercury. No statistical difference (t-test) between the sum of these two species determined by the GC-MPD based method and the recommended total mercury concentrations in the Seronorm samples was observed. Results for the determination of methyl- and inorganic mercury in 60 controls and 90 previously occupationally exposed (to inorganic mercury) workers are presented to illustrate the practical utility of the proposed method. No significantly elevated inorganic mercury concentrations between the two groups were evident.

  15. MP2, CCSD(T), and Density Functional Theory Study of the 2-Butyl Cation: New Insight into the Methyl- and Hydrogen-Bridged Structures.

    Science.gov (United States)

    Rasul, Golam; Prakash, G K Surya; Olah, George A

    2015-06-04

    Using the MP2, CCSD(T), and DFT (B3LYP) methods, the structures and energies of the 2-butyl cation (C4H9(+)) were calculated. Energetically, the C-C hyperconjugated structure 1 and hydrogen-bridged structure 2 were found to be almost identical at all levels. The (13)C NMR chemical shifts of 1 and 2 were computed by the GIAO-CCSD(T) method using different geometries. On the basis of calculated relative energies and calculated (13)C NMR chemical shifts, an equilibrium involving 1 and 2 (in a 50:50 ratio) seemed likely responsible for the experimentally observed (13)C NMR chemical shifts in superacid solutions at -80 °C. However, on the basis of computed and experimental frequencies the hydrogen-bridged structure 2 is most likely responsible for the experimentally observed frequencies in the solid state at -125 °C.

  16. Densities, speeds of sound, and refractive indices of the ternary mixtures (toluene + methyl acetate + butyl acetate) and (toluene + methyl acetate + methyl heptanoate) at 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Mariano, Alejandra [Departamento de Quimica, Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires 1400 (8300) Neuquen (Argentina); Postigo, Miguel [Departamento de Quimica, Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires 1400 (8300) Neuquen (Argentina)]. E-mail: postigo@uncoma.edu.ar; Gonzalez-Salgado, Diego [Departamento de Fisica Aplicada, Universidad de Vigo, Facultad de Ciencias del Campus de Ourense, E 32004 Ourense (Spain); Romani, Luis [Departamento de Fisica Aplicada, Universidad de Vigo, Facultad de Ciencias del Campus de Ourense, E 32004 Ourense (Spain)

    2007-02-15

    Density, {rho}, speed of sound, u, and refractive index, n {sub D}, at 298.15 K and atmospheric pressure have been measured over the entire composition range for (toluene + methyl acetate + butyl acetate) and (toluene + methyl acetate + methyl heptanoate) systems. Excess molar volumes, V {sup E}, isentropic compressibility, {kappa} {sub s}, isentropic compressibility deviations, {delta}{kappa} {sub s}, and changes of refractive index on mixing, {delta}n {sub D}, for the above systems, have been calculated from experimental data and fitted to Cibulka, Singh et al., and Nagata and Sakura equations, standard deviations from the regression lines are shown. Geometrical solution models, Tsao and Smith, Kholer, Jacob and Fitzner, Rastogi et al. were also applied to predict ternary properties from binary contributions.

  17. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid.

    Science.gov (United States)

    Liu, Hongzhu; Bian, Jiming; Wang, Zhonggang; Hou, Chuan-Jin

    2017-01-22

    Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE), vinyl acetate (VAc), n-butyl acrylate (BA), Veova 10, and acrylic acid (AA). The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV) accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  18. Microwave-assisted synthesis and crystal structure of oxo(diperoxo)(4,4'-di-tert-butyl-2,2'-bipyridine)-molybdenum(VI).

    Science.gov (United States)

    Amarante, Tatiana R; Almeida Paz, Filipe A; Gago, Sandra; Gonçalves, Isabel S; Pillinger, Martyn; Rodrigues, Alírio E; Abrantes, Marta

    2009-09-16

    The oxodiperoxo complex MoO(O2)(2)(tbbpy) (tbbpy = 4,4'-di-tert-butyl-2,2'- bipyridine) was isolated from the reaction of MoO2Cl(2)(tbbpy) in water under microwaveassisted heating at 120 masculineC for 4 h. The structure of the oxodiperoxo complex was determined by single crystal X-ray diffraction. The Mo(VI) centre is seven-coordinated with a geometry which strongly resembles a highly distorted bipyramid. Individual MoO(O2)(2)(tbbpy) complexes are interdigitated along the [010] direction to form a column. The crystal structure is formed by the close packing of the columnar-stacked complexes. Interactions between neighbouring columns are essentially of van der Waals type mediated by the need to effectively fill the available space.

  19. Microwave-Assisted Synthesis and Crystal Structure of Oxo(diperoxo(4,4'-di-tert-butyl-2,2'-bipyridine-molybdenum(VI

    Directory of Open Access Journals (Sweden)

    Alírio E. Rodrigues

    2009-09-01

    Full Text Available The oxodiperoxo complex MoO(O22(tbbpy (tbbpy = 4,4'-di-tert-butyl-2,2'- bipyridine was isolated from the reaction of MoO2Cl2(tbbpy in water under microwaveassisted heating at 120 ºC for 4 h. The structure of the oxodiperoxo complex was determined by single crystal X-ray diffraction. The MoVI centre is seven-coordinated with a geometry which strongly resembles a highly distorted bipyramid. Individual MoO(O22(tbbpy complexes are interdigitated along the [010] direction to form a column. The crystal structure is formed by the close packing of the columnar-stacked complexes. Interactions between neighbouring columns are essentially of van der Waals type mediated by the need to effectively fill the available space.

  20. Corrosion of Ni in 1-butyl-1-methyl-pyrrolidinium bis (trifluoromethylsulfonyl) amide room-temperature ionic liquid: an in situ X-ray imaging and spectromicroscopy study.

    Science.gov (United States)

    Bozzini, Benedetto; Gianoncelli, Alessandra; Kaulich, Burkhard; Kiskinova, Maya; Mele, Claudio; Prasciolu, Mauro

    2011-05-01

    This paper reports a pioneering application of soft X-ray scanning transmission microscopy (STXM), combined with micro-spot X-ray absorption spectroscopy (XAS) and X-ray fluorescence spectroscopy (XRF), for the investigation of the corrosion of metal electrodes in contact with room-temperature ionic liquids (RTIL). Using an open electrochemical cell in vacuo we explore some fundamental aspects of the aggressiveness of the 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)amide ([BMP][TFSA]) RTIL towards Ni under in situ electrochemical polarisation. The possibility of imaging electrochemically-induced morphological features in conjunction with micro-XAS and XRF spectroscopies has provided unprecedented details regarding the space distribution and chemical state of corrosion products.