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Sample records for organic solvent nanofiltration

  1. Morin-based nanofiltration membranes for organic solvent separation processes

    KAUST Repository

    Perez Manriquez, Liliana; Neelakanda, Pradeep; Peinemann, Klaus-Viktor

    2018-01-01

    In this work we demonstrate the successful optimization of the interfacial polymerization reaction for the manufacture of organic solvent nanofiltration membranes by replacing the toxic amines commonly used for this method with the natural occurring

  2. New Polymeric Membranes for Organic Solvent Nanofiltration

    KAUST Repository

    Aburabie, Jamaliah

    2017-05-01

    The focus of this dissertation was the development, synthesis and modification of polymers for the preparation of membranes for organic solvent nanofiltration. High chemical stability in a wide range of solvents was a key requirement. Membranes prepared from synthesized polymers as well as from commercial polymers were designed and chemically modified to reach OSN requirements. A solvent stable thin-film composite (TFC) membrane is reported, which is fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate. The membranes exhibited high fluxes towards solvents like THF, DMF and DMSO ranging around 20 L/m2 h at 5 bar with a MWCO of around 1000 g/mol. Ultrafiltration PTSC membranes were prepared by non-solvent induced phase separation and crosslinked with GPTMS. The crosslinking reaction was responsible for the formation of an inorganic-type-network that tuned the membrane pore size. The crosslinked membranes acquired high solvent stability in DMSO, DMF and THF with a MWCO above 1300 g/mol. Reaction Induced Phase Separation (RIPS) was introduced as a new method for the preparation of skinned asymmetric membranes. These membranes have two distinctive layers with different morphologies both from the same polymer. The top dense layer is composed of chemically crosslinked polymer chains while the bottom layer is a porous structure formed by non-crosslinked polymer chains. Such membranes were tested for vitamin B12 in solvents after either crosslinking the support or dissolving the support and fixing the freestanding membrane on alumina. Pebax® 1657 was utilized for the preparation of composite membranes by simple coating. Porous PAN membranes were coated with Pebax® 1657 which was then crosslinked using TDI. Crosslinked Pebax® membranes show high stability towards ethanol, propanol and acetone. The membranes were also stable in DMF once crosslinked PAN supports were used. Sodium alginate polymer was investigated for the preparation of thin film composite

  3. Morin-based nanofiltration membranes for organic solvent separation processes

    KAUST Repository

    Perez Manriquez, Liliana

    2018-02-26

    In this work we demonstrate the successful optimization of the interfacial polymerization reaction for the manufacture of organic solvent nanofiltration membranes by replacing the toxic amines commonly used for this method with the natural occurring bio-polyphenol morin. For the manufacture of this type of OSN membrane a crosslinked PAN support was coated by interfacial polymerization using morin as the monomer of the aqueous phase and terephtaloyl chloride as the monomer of the organic phase. These membranes showed an exceptional performance and resistance to NMP by having a a permeance of 0.3L/m2 h bar in NMP with a rejection of 96% of Brilliant Blue dye which has a molecular weight of 825.97g/mol, making these membranes attractive for harsh industrial separation processes due to their ease of manufacture, low cost, and excellent performance.

  4. Surface modification of PTMSP membranes by plasma treatment: Asymmetry of transport in organic solvent nanofiltration.

    Science.gov (United States)

    Volkov, A V; Tsarkov, S E; Gilman, A B; Khotimsky, V S; Roldughin, V I; Volkov, V V

    2015-08-01

    For the first time, the effect of asymmetry of the membrane transport was studied for organic solvents and solutes upon their nanofiltration through the plasma-modified membranes based on poly(1-trimethylsilyl-1-propyne) (PTMSP). Plasma treatment is shown to provide a marked hydrophilization of the hydrophobic PTMSP surface (the contact angle of water decreases from 88 down to 20°) and leads to the development of a negative charge of -5.2 nC/cm(2). The XPS measurements prove the formation of the oxygen-containing groups (Si-O and C-O) due to the surface modification. The AFM images show that the small-scale surface roughness of the plasma-treated PTMSP sample is reduced but the large-scale surface heterogeneities become more pronounced. The modified membranes retain their hydrophilic surface properties even after the nanofiltration tests and 30-day storage under ambient conditions. The results of the filtration tests show that when the membrane is oriented so that its modified layer contacts the feed solution, the membrane permeability for linear alcohols (methanol-propanol) and acetone decreases nearly two times. When the modified membrane surface faces the permeate, the membrane is seen to regain its transport characteristics: the flux becomes equal to that of the unmodified PTMSP. The well-pronounced effect of the transport asymmetry is observed for the solution of the neutral dye Solvent Blue 35 in methanol, ethanol, and acetone. For example, the initial membrane shows the negative retention for the Solvent Blue 35 dye (-16%) upon its filtration from the ethanol solution whereas, for the modified PTMSP membrane, the retention increases up to 17%. Various effects contributing to the asymmetry of the membrane transport characteristics are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Crosslinked poly(ether block amide) composite membranes for organic solvent nanofiltration applications

    KAUST Repository

    Aburabie, Jamaliah; Peinemann, Klaus-Viktor.

    2016-01-01

    Poly(ether block amide) – Pebax® – based membranes are well described for gas separation applications. But only a few publications exist for their application in pressure driven liquid applications like ultrafiltration and nanofiltration. Here we use the commercially available Pebax® 1657 for the preparation of membranes for the filtration of organic solvents. Porous polyacrylonitrile membranes were coated with Pebax® 1657 which was then crosslinked. Toluene diisocyanate (TDI) was used as a crosslinker agent for the coating. Reaction time and crosslinker concentration were optimized for the aimed application. The Pebax® coating and the impact of the TDI on the resulting crosslinked membranes were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). SEM analysis shows a uniform thin coating of the PEBAX that covers the pores of the PAN membranes. FTIR and DSC analysis confirm the crosslinking reaction. Crosslinked Pebax® membranes show high stability toward ethanol propanol, acetone and even dimethylformamide (DMF). In the case of DMF applications, the standard PAN was replaced by crosslinked PAN developed in our laboratory. In order to increase the membranes permeances, graphene oxide (GO) nanosheets were incorporated in the Pebax® coating. These GO containing membranes showed strongly increased permeances for selected solvents. © 2016 Elsevier B.V.

  6. Crosslinked poly(ether block amide) composite membranes for organic solvent nanofiltration applications

    KAUST Repository

    Aburabie, Jamaliah

    2016-10-01

    Poly(ether block amide) – Pebax® – based membranes are well described for gas separation applications. But only a few publications exist for their application in pressure driven liquid applications like ultrafiltration and nanofiltration. Here we use the commercially available Pebax® 1657 for the preparation of membranes for the filtration of organic solvents. Porous polyacrylonitrile membranes were coated with Pebax® 1657 which was then crosslinked. Toluene diisocyanate (TDI) was used as a crosslinker agent for the coating. Reaction time and crosslinker concentration were optimized for the aimed application. The Pebax® coating and the impact of the TDI on the resulting crosslinked membranes were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). SEM analysis shows a uniform thin coating of the PEBAX that covers the pores of the PAN membranes. FTIR and DSC analysis confirm the crosslinking reaction. Crosslinked Pebax® membranes show high stability toward ethanol propanol, acetone and even dimethylformamide (DMF). In the case of DMF applications, the standard PAN was replaced by crosslinked PAN developed in our laboratory. In order to increase the membranes permeances, graphene oxide (GO) nanosheets were incorporated in the Pebax® coating. These GO containing membranes showed strongly increased permeances for selected solvents. © 2016 Elsevier B.V.

  7. Thin-film composite crosslinked polythiosemicarbazide membranes for organic solvent nanofiltration (OSN)

    KAUST Repository

    Aburabie, Jamaliah; Neelakanda, Pradeep; Karunakaran, Madhavan; Peinemann, Klaus-Viktor

    2015-01-01

    In this work we report a new class of solvent stable thin-film composite (TFC) membrane fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate that exhibits superior stability compared with other solvent stable polymeric membranes

  8. Optimization of preparation conditions of polyamide thin film composite membrane for organic solvent nanofiltration

    International Nuclear Information System (INIS)

    Namvar-Mahboub, Mahdieh; Pakizeh, Majid

    2014-01-01

    Separation performance of polyamide composite membranes is affected by several parameters during formation of thin upper layer via interfacial polymerization. We investigated the effect of various polyamide synthesis conditions on the performance of organic solvent resistant polyamide composite membranes through the model equations designed by 2-level fractional factorial design. The dewaxing solvent recovery was selected as separation process. Five factors were changed in two level includin; TMC concentration (0.05-0.1%), MPD concentration (1-2%), support immersion time in organic solution (2-4 min), support immersion time in aqueous solution (1-2 min), and curing temperature (70-80 .deg. C). The resultant equations showed 93.48% and 94.82% of the variability (R 2 adj ) in data used to fit oil rejection and permeate flux models, respectively. The analysis of variance revealed that both models were high significant. It was also observed that TMC concentration, MPD concentration and immersion time in TMC have more pronounced effect on the oil rejection and permeate flux than other factors and interactions. Optimal polyamide preparation conditions were obtained using multiple response method for 94% oil rejection as target value. According to the results, the best value of permeate flux (8.86 l/(m 2 ·h)) was found at TMC concentration of 0.1%, MPD concentration of 1.94%, immersion time in TMC of 3.88 min, immersion time in MPD of 1.95 min and curing temperature of 71.96 .deg. C with desirability factor of 1

  9. Sub-6 nm Thin Cross-Linked Dopamine Films with High Pressure Stability for Organic Solvent Nanofiltration

    KAUST Repository

    Perez Manriquez, Liliana

    2016-07-11

    Interfacial polymerization of dopamine and terephtaloyl chloride is performed on a porous crosslinked polyacrylonitrile support membrane. The resulting polymer layer has a smooth surface and is ultrathin (about 5 nm). The chemical nature of the interfacially polymerized layer is characterized by Fourier transform infrared spectroscopy and by X-ray photoelectron spectroscopy. The thin-film composite membrane is stable in aggressive solvents like dimethylformamide (DMF) and the membrane shows high solvent permeances combined with a molecular weight cut-off below 800 g mol-1. The remarkable stability in DMF, the ease of preparation as well as the extremely thin and smooth selective layer make this new type of bioinspired membrane attractive for solvent resistant nanofiltration. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Thin-film composite crosslinked polythiosemicarbazide membranes for organic solvent nanofiltration (OSN)

    KAUST Repository

    Aburabie, Jamaliah

    2015-01-01

    In this work we report a new class of solvent stable thin-film composite (TFC) membrane fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate that exhibits superior stability compared with other solvent stable polymeric membranes reported up to now. Integrally skinned asymmetric PTSC membranes were prepared by the phase inversion process and crosslinked with an aromatic bifunctional crosslinker to improve the solvent stability. TFC membranes were obtained via interfacial polymerization using trimesoyl chloride (TMC) and diaminopiperazine (DAP) monomers. The membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and contact angle measurement.The membranes exhibited high fluxes toward solvents like tetrahydrofuran (THF), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) ranging around 20L/m2 h at 5bar with a molecular weight cut off (MWCO) of around 1000g/mol. The PTSC-based thin-film composite membranes are very stable toward polar aprotic solvents and they have potential applications in the petrochemical and pharmaceutical industry.

  11. Effective Interfacially Polymerized Polyester Solvent Resistant Nanofiltration Membrane from Bioderived Materials

    KAUST Repository

    Abdellah, Mohamed H.; Perez Manriquez, Liliana; Puspasari, Tiara; Scholes, Colin A.; Kentish, Sandra E.; Peinemann, Klaus-Viktor

    2018-01-01

    Utilization of sustainable and environmentally friendly solvents for the preparation of membranes has attracted growing interest in recent years. In this work, a polyester thin film composite solvent resistant nanofiltration (SRNF) membrane

  12. Tannin-based thin-film composite membranes for solvent nanofiltration

    KAUST Repository

    Perez Manriquez, Liliana

    2017-06-28

    The natural oligomer tannic acid was used as a reactant for an interfacial polymerisation on top of a crosslinked polyacrylonitrile (PAN) membrane. The PAN membrane was soaked with the aqueous tannic acid solution and contacted with a dilute solution of teraphtaloylchloride in hexane. Since both layers, the PAN support and the thin tannin-based layer, are highly crosslinked, the resulting thin film composite membrane is stable in harsh solvent environments such as N-Methyl-2-pyrrolidone (NMP). NMP permeances of up to 0.09L/m2 h bar with a molecular weight cut-off of approximately 800g/mol were obtained. The exceptional stability in NMP and the incorporation of natural compounds like tannic acid for the manufacture of organic solvent nanofiltration membranes provides a cost-effective alternative for industrial separations due to the simplicity of the interfacial reaction and the replacement of the commonly applied toxic aromatic amines. The scale up of the manufacturing process is not difficult; the low price of the natural tannic acid is another advantage.

  13. Nanofiltration-Enabled In Situ Solvent and Reagent Recycle for Sustainable Continuous-Flow Synthesis.

    Science.gov (United States)

    Fodi, Tamas; Didaskalou, Christos; Kupai, Jozsef; Balogh, Gyorgy T; Huszthy, Peter; Szekely, Gyorgy

    2017-09-11

    Solvent usage in the pharmaceutical sector accounts for as much as 90 % of the overall mass during manufacturing processes. Consequently, solvent consumption poses significant costs and environmental burdens. Continuous processing, in particular continuous-flow reactors, have great potential for the sustainable production of pharmaceuticals but subsequent downstream processing remains challenging. Separation processes for concentrating and purifying chemicals can account for as much as 80 % of the total manufacturing costs. In this work, a nanofiltration unit was coupled to a continuous-flow rector for in situ solvent and reagent recycling. The nanofiltration unit is straightforward to implement and simple to control during continuous operation. The hybrid process operated continuously over six weeks, recycling about 90 % of the solvent and reagent. Consequently, the E-factor and the carbon footprint were reduced by 91 % and 19 %, respectively. Moreover, the nanofiltration unit led to a solution of the product eleven times more concentrated than the reaction mixture and increased the purity from 52.4 % to 91.5 %. The boundaries for process conditions were investigated to facilitate implementation of the methodology by the pharmaceutical sector. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Solvent-resistant nanofiltration for product purification and catalyst recovery in click chemistry reactions.

    Science.gov (United States)

    Cano-Odena, Angels; Vandezande, Pieter; Fournier, David; Van Camp, Wim; Du Prez, Filip E; Vankelecom, Ivo F J

    2010-01-18

    The quickly developing field of "click" chemistry would undoubtedly benefit from the availability of an easy and efficient technology for product purification to reduce the potential health risks associated with the presence of copper in the final product. Therefore, solvent-resistant nanofiltration (SRNF) membranes have been developed to selectively separate "clicked" polymers from the copper catalyst and solvent. By using these solvent-stable cross-linked polyimide membranes in diafiltration, up to 98 % of the initially present copper could be removed through the membrane together with the DMF solvent, the polymer product being almost completely retained. This paper also presents the first SRNF application in which the catalyst permeates through the membrane and the reaction product is retained.

  15. Organic Solvent Tropical Report

    International Nuclear Information System (INIS)

    COWLEY, W.L.

    2000-01-01

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines

  16. Effective Interfacially Polymerized Polyester Solvent Resistant Nanofiltration Membrane from Bioderived Materials

    KAUST Repository

    Abdellah, Mohamed H.

    2018-05-18

    Utilization of sustainable and environmentally friendly solvents for the preparation of membranes has attracted growing interest in recent years. In this work, a polyester thin film composite solvent resistant nanofiltration (SRNF) membrane is prepared by interfacial polymerization on a cellulose support. The cellulose support is prepared by nonsolvent‐induced phase separation from a dope solution containing an ionic liquid as an environmentally friendly solvent (negligible vapor pressure). The polyester film is formed via the interfacial reaction between quercetin, a plant‐derived polyphenol, and terephthaloyl chloride. Alpha‐pinene is used as a green alternative solvent to dissolve terephthaloyl chloride (TPC) while quercetin is dissolved in a 0.2 m NaOH solution. The interfacial polymerization reaction is successfully confirmed by Fourier transform infrared and X‐ray photoelectron spectroscopy while scanning electron and atomic force microscopy are used to characterize the membrane structure. The composite membrane shows an outstanding performance with a molecular weight cut‐off around 330 Da combined with a dimethylformamide (DMF) permeance up to 2.8 L m−2 bar−1 h−1. The membrane is stable in strong aprotic solvents such as DMF offering potential application in the pharmaceutical and petrochemical industries.

  17. Rejection of Organic Micropollutants by Clean and Fouled Nanofiltration Membranes

    Directory of Open Access Journals (Sweden)

    Lifang Zhu

    2015-01-01

    Full Text Available The rejection of organic micropollutants, including three polycyclic aromatic hydrocarbons (PAHs and three phthalic acid esters (PAEs, by clean and fouled nanofiltration membranes was investigated in the present study. The rejection of organic micropollutants by clean NF90 membranes varied from 87.9 to more than 99.9%, while that of NF270 membranes ranged from 32.1 to 92.3%. Clear time-dependence was observed for the rejection of hydrophobic micropollutants, which was attributed to the adsorption of micropollutants on the membrane. Fouling with humic acid had a negligible influence on the rejection of organic micropollutants by NF90 membranes, while considerable effects were observed with NF270 membranes, which are significantly looser than NF90 membranes. The observed enhancement in the rejection of organic micropollutants by fouled NF270 membranes was attributed to pore blocking, which was a dominating fouling mechanism for loose NF membranes. Changes in the ionic strength (from 10 to 20 mM reduced micropollutant rejection by both fouled NF membranes, especially for the rejection of dimethyl phthalate and diethyl phthalate by NF270 membranes (from 65.8 to 25.0% for dimethyl phthalate and 75.6 to 33.3% for diethyl phthalate.

  18. CHEMICAL CLEANING OF NANOFILTRATION MEMBRANES FOULED BY ORGANIC MATTERS

    Directory of Open Access Journals (Sweden)

    CHARLENE C. H. KOO

    2016-07-01

    Full Text Available Membrane fouling is a term to describe non-integral substance on membrane surface which results in rapid decline of permeation flux and deteriorate the performance of membrane. Chemical cleaning agents especially like alkaline cleaners are most widely employed to restore the membrane performance. This research mainly investigated the potential use of sodium hydroxide (NaOH and sodium hypochlorite (NaOCl as the chemical cleaning agents to restore the permeate flux of organically fouled nanofiltration (NF membranes under varying applied pressure and flow condition. The performances of the cleaning protocols were quantified using flux recovery and resistance removal. The results demonstrated that NaOCl is more effective than NaOH. This observation is also in line with FTIR analysis in which the transmittance intensity showed by FTIR spectra of NaOCl is higher than that of NaOH. The results also reported that higher flux recovery and resistance removal were achieved when the fouled NF membranes were cleaned with higher concentration of chemical agents and applied pressure. However, the improvements of flux recovery and resistance removal by increasing the applied pressure were found insignificant at higher applied pressure range (16 to 18 bar than the lower applied pressure range (i.e. 12 to 14 bar. This research plays an important role by identifying the key parameters that could restore the flux of organically fouled NF membranes significantly.

  19. Organic Removal Efficiency of the Nanofiltration and Adsorption Hybrid System in High Strength Wastewater

    Directory of Open Access Journals (Sweden)

    Amir Hessam Hassani

    2011-03-01

    Full Text Available Surface and groundwater resources are increasingly jeopardized by discharges from pharmaceutical, chemical, and detergent plants. The high pollutant load of the effluents from these industries requires specific treatments. The objective of this research was to study and compare the nanofiltration and adsorption hybrid system with the plain nanofiltration system in wastewater treatment.For this purpose, a pilot nanofiltration system with a capacity of 7.6 m3/d using 1 and 5 micron filters and a FILMTEC NF90-4040 membrane was used in the first phase of the study. In the second phase, granular activated carbon cartridges were used. Inluent and effluent discharges as well as the COD removal were measured in both systems under variable times and organic load conditions. The results showed that COD removal efficiency was higher in the hybrid system than in the plain naonofiltration one. In the hybrid system, the Maximum in the hybrid system, the COD removal efficiencies achieved for organic loads of 1000, 2000, and 3000 mg/L were 99%, 95.86%, and 92.93%, respectively. The same values for the plain nanofiltration system were 87.34%, 50%, and 29.41%, respectively. It was found that polarization and membrane fouling decreased both the effluent flow and the COD removal efficiency with time. Fouling of the membrane was, however, lower in the hybrid system compared to the plain nanofiltration; thus, the hybrid system was associated with higher values of COD removal and delayed membrane fouling.

  20. Organic solvent topical report

    Energy Technology Data Exchange (ETDEWEB)

    Cowley, W.L.

    1998-04-30

    This report is the technical basis for the accident and consequence analyses used in the Hanford Tank Farms Basis for Interim Operation. The report also contains the scientific and engineering information and reference material needed to understand the organic solvent safety issue. This report includes comments received from the Chemical Reactions Subcommittee of the Tank Advisory Panel.

  1. Organic solvent topical report

    International Nuclear Information System (INIS)

    Cowley, W.L.

    1998-01-01

    This report is the technical basis for the accident and consequence analyses used in the Hanford Tank Farms Basis for Interim Operation. The report also contains the scientific and engineering information and reference material needed to understand the organic solvent safety issue. This report includes comments received from the Chemical Reactions Subcommittee of the Tank Advisory Panel

  2. Organic solvent topical report

    Energy Technology Data Exchange (ETDEWEB)

    COWLEY, W.L.

    1999-05-13

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed.

  3. Organic solvent topical report

    International Nuclear Information System (INIS)

    COWLEY, W.L.

    1999-01-01

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed

  4. Tannin-based thin-film composite membranes for solvent nanofiltration

    KAUST Repository

    Perez Manriquez, Liliana; Neelakanda, Pradeep; Peinemann, Klaus-Viktor

    2017-01-01

    ). NMP permeances of up to 0.09L/m2 h bar with a molecular weight cut-off of approximately 800g/mol were obtained. The exceptional stability in NMP and the incorporation of natural compounds like tannic acid for the manufacture of organic solvent

  5. Solvents and solvent effects in organic chemistry

    National Research Council Canada - National Science Library

    Reichardt, C; Welton, T

    2011-01-01

    .../guest complexation equilibria and reactions in biphasic solvent systems and neoteric solvents, respectively. More than 900 new references have been added, giving preference to review articles, and many older ones have been deleted. New references either replace older ones or are added to the end of the respective reference list of each chapter. Th...

  6. Priority organic micropollutants in water sources in Flanders and the Netherlands and assessment of removal possibilities with nanofiltration

    International Nuclear Information System (INIS)

    Verliefde, Arne; Cornelissen, Emile; Amy, Gary; Bruggen, Bart van der; Dijk, Hans van

    2007-01-01

    The occurrence of organic micropollutants in ground- and surface waters has become an important concern for the drinking water industry, mainly because of possible related health effects. Due to the polar nature of some of these pollutants, they are not completely removed by traditional water treatment barriers. This paper offers an overview of priority organic micropollutants and their occurrence in Flemish and Dutch water sources. Furthermore, rejection by nanofiltration is qualitatively predicted for the selected priority micropollutants. The qualitative prediction is based on the values of key solute and membrane parameters in nanofiltration. Predicted values are then compared with experimental values obtained from literature. Overall, the qualitative predictions are roughly in agreement with literature values. Prediction based on key parameters may thus prove to be a very quick and useful technique to assess the implementation of nanofiltration as a treatment step for organic micropollutants in drinking water plant design. - The article provides a quick and powerful prediction tool for the removal of organic micropollutants by nanofiltration, based on readily available parameter values

  7. Multiple sclerosis and organic solvents

    DEFF Research Database (Denmark)

    Mortensen, J T; Brønnum-Hansen, Henrik; Rasmussen, K

    1998-01-01

    We investigated a possible causal relation between exposure to organic solvents in Danish workers (housepainters, typographers/printers, carpenters/cabinetmakers) and onset of multiple sclerosis. Data on men included in the Danish Multiple Sclerosis Register (3,241 men) were linked with data from......, and butchers. Over a follow-up period of 20 years, we observed no increase in the incidence of multiple sclerosis among men presumed to be exposed to organic solvents. It was not possible to obtain data on potential confounders, and the study design has some potential for selection bias. Nevertheless......, the study does not support existing hypotheses regarding an association between occupational exposure to organic solvents and multiple sclerosis....

  8. Optimizing Hollow Fibre Nanofiltration for Organic Matter Rich Lake Water

    Directory of Open Access Journals (Sweden)

    Alexander Keucken

    2016-09-01

    Full Text Available Over the years, various technologies have been utilized for Natural Organic Matter (NOM removal with varying degrees of success. Conventional treatment methods comprising of coagulation, flocculation, sedimentation, or filtration are widely used to remove NOM. An alternative to these conventional methods is to use spiral wound membranes. These membranes tend to remove too much hardness whilst being ineffective in disinfection. They also have a low tolerance to chlorine and thus, have limited chemical cleaning options. In this study, we investigated how an alternative and new innovative filtration concept, based on capillary NF membranes from modified polyethersulfone (PES, may be used to treat soft but humus-rich surface waters. Comprehensive performance tests, with a fully automated membrane pilot equipped with a full-scale sized test module (40 m2 membrane surface, were conducted at WTP Görvälnverket, which is operated by the water utility Norrvatten, providing drinking water from Mälaren (SUVA = 2.7–3.3, TOC = 7.0–10.0 mg·L−1 for about 500,000 people in the northern part of the Swedish capital of Stockholm. The removal of both UV and DOC was modeled using a solution diffusion approach. The optimized parameters allow deducing optimal operation conditions with respect to energy, water consumption, and permeate water quality. Optimal cross flow velocity was determined to be 0.75 m·s−1 at 80% recovery and a flux of 12–18 L·m−2·h−1. Under these conditions, 80% of the UV, 75% of the Humic Substances (MW = 600 and 70% of TOC were removed (from 8 to below 2 mg·L−1. A higher cross flow velocity led to marginal improvement (+2% while both higher and lower membrane fluxes degraded permeate water quality. Apparent optimized diffusion coefficients for UV and TOC were around 1.2–2.4 × 10−10·m2·s−1 and were similar to values found in the literature. Due to their higher diffusion coefficients and higher permeability

  9. Effect of fouling on removal of trace organic compounds by nanofiltration

    Directory of Open Access Journals (Sweden)

    S. Hajibabania

    2011-12-01

    Full Text Available The fate of chemical of concern is not yet fully understood during treatment of impaired waters. The aim of this paper is to assess the impact of different organic-based fouling layers on the removal of a large range of trace organics. Both model and real water samples (mixed with trace organic contaminants at environmental concentration of 2 μg l−1 were used to simulate fouling in nanofiltration under controlled environment. The new and fouled membranes were systematically characterised for surface charge, hydrophobicity and roughness. It was observed that fouling generally reduced the membrane surface charge; however, the alterations of the membrane hydrophobicity and surface roughness were dependent on the foulants composition. The rejection of charged trace organics was observed to be improved due to the increased electrostatic repulsion by fouled membranes and the adsorption of the trace organic chemicals onto organic matters. On the other hand, the removal of nonionic compounds decreased when fouling occurred, due to the presence of cake enhanced concentration polarization. The fouling layer structure was found to play an important role in the rejection of the trace organic compounds.

  10. Thin porphyrin composite membranes with enhanced organic solvent transport

    KAUST Repository

    Phuoc, Duong

    2018-05-01

    Extending the stability of polymeric membranes in organic solvents is important for applications in chemical and pharmaceutical industry. Thin-film composite membranes with enhanced solvent permeance are proposed, using porphyrin as a building block. Hybrid polyamide films are formed by interfacial polymerization of 5,10,15,20-(tetra-4-aminophenyl)porphyrin/m-phenylene diamine (MPD) mixtures with trimesoyl chloride. Porphyrin is a non-planar molecule, containing a heterocyclic tetrapyrrole unit. Its incorporation into a polyamide film leads to higher free volume than that of a standard polyamide film. Polyamide films derived from porphyrin and MPD amines with a fixed total amine concentration of 1wt% and various porphyrin/MPD ratios were fabricated and characterized. The porphyrin/MPD polyamide film was complexed with Cu(II), due to the binding capacity of porphyrin to metal ions. By coupling scanning transmission electron microscopy (STEM) with electron energy-loss spectroscopy (EELS), Cu mapping was obtained, revealing the distribution of porphyrin in the interfacial polymerized layer. By using porphyrin as amine-functionalized monomer a membrane with thin selective skin and enhanced solvent transport is obtained, with good dye selectivity in the nanofiltration range. For instance, an ultra-fast hexane permeance, 40-fold increased, was confirmed when using 0.5/0.5 porphyrin/MPD mixtures, instead of only MPD as amine monomer. A rejection of 94.2% Brilliant Blue R (826g/mol) in methanol was measured.

  11. Proposing nanofiltration as acceptable barrier for organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2010-10-01

    For water reuse applications, " tight" nanofiltration (NF) membranes (of polyamide) as an alternative to reverse osmosis (RO) can be an effective barrier against pharmaceuticals, pesticides, endocrine disruptors and other organic contaminants. The use of RO in existing water reuse facilities is addressed and questioned, taking into consideration that tight NF can be a more cost-effective and efficient technology to target the problem of organic contaminants. It was concluded that tight NF is an acceptable barrier for organic contaminants because its removal performance approaches that of RO, and because of reduced operation and maintenance (O&M) costs in long-term project implementation. Average removal of neutral compounds (including 1,4-dioxane) was about 82% and 85% for NF and RO, respectively, and average removal of ionic compounds was about 97% and 99% for NF and RO, respectively. In addition, " loose" NF after aquifer recharge and recovery (ARR) can be an effective barrier against micropollutants with removals over 90%. When there is the presence of difficult to remove organic contaminants such as NDMA and 1,4-dioxane; for 1,4-dioxane, source control or implementation of treatment processes in wastewater treatment plants will be an option; for NDMA, a good strategy is to limit its formation during wastewater treatment, but there is evidence that biodegradation of NDMA can be achieved during ARR. © 2010 Elsevier B.V.

  12. Iodine removing method in organic solvent

    International Nuclear Information System (INIS)

    Suzuki, Takeo; Sakurai, Manabu

    1988-01-01

    Purpose: To effectively remove iodine in an organic solvent to thereby remove iodine in the solvent that can be re-used or put to purning treatment. Method: Organic solvent formed from wastes of nuclear facilities is mixed with basic lead acetate, or silica gel or activated carbon incorporated with such a compound to adsorb iodine in the organic solvent to the basic lead acetate. Then, iodine in the organic solvent is removed by separating to eliminate the basic lead acetate adsorbing iodine from the organic solvent or by passing the organic solvent through a tower or column charged or pre-coated with silica gel or activated carbon incorporated with lead acetate. By using basic lead acetate as the adsorbents, iodine can effective by adsorbed and eliminated. Thus, the possibility of circumstantial release of iodine can be reduced upon reusing or burning treatment of the organic solvent. (Kamimura, M.)

  13. Concept of Compound Retention Time for Organic Micro Pollutants in Anaerobic Membrane Bioreactor with Nanofiltration

    KAUST Repository

    Pan, Jiangjiang

    2011-01-01

    to control OMPs wastage. An innovative hybrid process, anaerobic membrane bioreactor with nanofiltration (AnMBR-NF), in which enhanced OMPs removal is possible based on the concept of compound retention time (CRT) through coupling anaerobic biodegradation

  14. Organic micro-pollutants’ removal via anaerobic membrane bioreactor with ultrafiltration and nanofiltration

    KAUST Repository

    Wei, Chunhai

    2015-12-15

    The removal of 15 organic micro-pollutants (OMPs) in synthetic municipal wastewater was investigated in a laboratory-scale mesophilic anaerobic membrane bioreactor (AnMBR) using ultrafiltration and AnMBR followed by nanofiltration (NF), where powdered activated carbon (PAC) was added to enhance OMPs removal. No significant effects of OMPs spiking and NF connection on bulk organics removal and biogas production were observed. Amitriptyline, diphenhydramine, fluoxetine, sulfamethoxazole, TDCPP and trimethoprim showed readily biodegradable characteristics with consistent biological removal over 80%. Atrazine, carbamazepine, DEET, Dilantin, primidone and TCEP showed refractory characteristics with biological removal below 40%. Acetaminophen, atenolol and caffeine showed a prolonged adaption time of around 45 d, with initial biological removal below 40% and up to 50-80% after this period. Most readily biodegradable OMPs contained a strong electron donating group. Most refractory OMPs contained a strong electron withdrawing group or a halogen substitute. NF showed consistent high rejection of 80-92% with an average of 87% for all OMPs, which resulted in higher OMPs removal in AnMBR-NF than in AnMBR alone, especially for refractory OMPs. Limited sorption performance of PAC for OMPs removal was mainly due to low and batch dosage (100 mg/L) as well as the competitive sorption caused by bulk organics.

  15. Organic solvents in electromembrane extraction: recent insights

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2016-01-01

    the introduction. Under the influence of an electrical field, EME is based on electrokinetic migration of the analytes through a supported liquid membrane (SLM), which is an organic solvent immobilized in the pores of the polymeric membrane, and into the acceptor solution. Up to date, close to 150 research...... articles with focus on EME have been published. The current review summarizes the performance of EME with different organic solvents and discusses several criteria for efficient solvents in EME. In addition, the authors highlight their personal perspective about the most promising organic solvents for EME...... and have indicated that more fundamental work is required to investigate and discover new organic solvents for EME....

  16. Method of decomposing radioactive organic solvent wastes

    International Nuclear Information System (INIS)

    Uki, Kazuo; Ichihashi, Toshio; Hasegawa, Akira; Sato, Tatsuaki

    1986-01-01

    Purpose: To decompose radioactive organic solvent wastes or radioactive hydrocarbon solvents separated therefrom into organic materials under moderate conditions, as well as greatly decrease the amount of secondary wastes generated. Method: Radioactive organic solvent wastes comprising an organic phosphoric acid ester ingredient and a hydrocarbon ingredient as a diluent therefor, or radioactive hydrocarbon solvents separated therefrom are oxidatively decomposed by hydrogen peroxide in an aqueous phosphoric acid solution of phosphoric acid metal salts finally into organic materials to perform decomposing treatment for the radioactive organic solvent wastes. The decomposing reaction is carried out under relatively moderate conditions and cause less burden to facilities or the likes. Further, since the decomposed liquid after the treatment can be reused for the decomposing reaction as a catalyst solution secondary wastes can significantly be decreased. (Yoshihara, H.)

  17. Handbook of organic solvent properties

    CERN Document Server

    Smallwood, Ian

    2012-01-01

    The properties of 72 of the most commonly used solvents are given, tabulated in the most convenient way, making this book a joy for industrial chemists to use as a desk reference. The properties covered are those which answer the basic questions of: Will it do the job? Will it harm the user? Will it pollute the air? Is it easy to handle? Will it pollute the water? Can it be recovered or incinerated? These are all factors that need to be considered at the early stages of choosing a solvent for a new product or process.A collection of the physical properties of most commonly used solvents, their

  18. Concept of Compound Retention Time for Organic Micro Pollutants in Anaerobic Membrane Bioreactor with Nanofiltration

    KAUST Repository

    Pan, Jiangjiang

    2011-12-01

    Organic micropollutants (OMPs) have received more and more attention in recent years due to their potential harmful effects on public health and aquatic ecosystems, and eliminating OMPs in wastewater treatment systems is an important solution to control OMPs wastage. An innovative hybrid process, anaerobic membrane bioreactor with nanofiltration (AnMBR-NF), in which enhanced OMPs removal is possible based on the concept of compound retention time (CRT) through coupling anaerobic biodegradation and NF rejection, is proposed and examined in terms of preliminary feasibility in this study. First, NF membrane screening through sludge water dead-end filtration tests demonstrated that KOCH NF200 (molecular weight cut-off (MWCO) 200 Da, acid/base stable) performed best in organic matter rejection. Then, selected OMPs (ketobrofen and naproxen) in MQ water and a biologically treated wastewater matrix were filtered through NF200 under constant-pressure dead-end mode, with and without stirring, and several methods (contact angle, scanning electronic microscopy, Zeta potential, Fourier transform infra-red spectroscopy) were used to characterize membranes. Results show selected OMPs in MQ could be rejected (about 40%) by a clean NF200 membrane. The main rejection mechanism was initial absorption by the membrane followed by size exclusion (electric charge interaction plays a less important role). The wastewater matrix could enhance the rejection significantly (up to 90%) because effluent organic matter (EfOM) enhanced size exclusion and electric charge interaction through blocking membrane pores and forming a gel layer as well as binding some OMPs through partitioning followed by retention by NF. Third, an anaerobic bioreactor was set up to evaluate the anaerobic biodegradability of selected OMPs. Results showed selected OMPs could be absorbed by sludge and reached equilibrium within one day, and then were consumed by anaerobic microorganism with a half life 9.4 days for

  19. Organic Solvent Tolerant Lipases and Applications

    Directory of Open Access Journals (Sweden)

    Shivika Sharma

    2014-01-01

    Full Text Available Lipases are a group of enzymes naturally endowed with the property of performing reactions in aqueous as well as organic solvents. The esterification reactions using lipase(s could be performed in water-restricted organic media as organic solvent(s not only improve(s the solubility of substrate and reactant in reaction mixture but also permit(s the reaction in the reverse direction, and often it is easy to recover the product in organic phase in two-phase equilibrium systems. The use of organic solvent tolerant lipase in organic media has exhibited many advantages: increased activity and stability, regiospecificity and stereoselectivity, higher solubility of substrate, ease of products recovery, and ability to shift the reaction equilibrium toward synthetic direction. Therefore the search for organic solvent tolerant enzymes has been an extensive area of research. A variety of fatty acid esters are now being produced commercially using immobilized lipase in nonaqueous solvents. This review describes the organic tolerance and industrial application of lipases. The main emphasis is to study the nature of organic solvent tolerant lipases. Also, the potential industrial applications that make lipases the biocatalysts of choice for the present and future have been presented.

  20. Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

    International Nuclear Information System (INIS)

    Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi

    2015-01-01

    The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity

  1. Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

    Energy Technology Data Exchange (ETDEWEB)

    Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi [Universiti Teknologi Malaysia, Skudai (Malaysia)

    2015-04-15

    The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity.

  2. Organic solvents from sugar cane molasses

    Energy Technology Data Exchange (ETDEWEB)

    Oeser, H

    1970-01-01

    The production of organic solvents by fermentation of low priced cane molasses is discussed. Processes described and illustrated in detail include the production of acetone, butanol, ethanol, acetic acid, ethyl acetate and butyl acetate.

  3. Rejection of Emerging Organic Contaminants by Nanofiltration and Reverse Osmosis Membranes : Effects of Fouling, Modelling and Water Reuse

    NARCIS (Netherlands)

    Yangali Quintanilla, V.

    2010-01-01

    The book contains a description of the presence of micropollutants (medicines, hormones, pesticides) in surface water and shows that conventional water treatment poorly removes micropollutants. Nanofiltration and reverse osmosis are more appropriate technologies; however removals can vary depending

  4. Prediction of the rejection of organic compounds (neutral and ionic) by nanofiltration and reverse osmosis membranes using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Ammi, Yamina; Khaouane, Latifa; Hanini, Salah [University of Medea, Medea (Algeria)

    2015-11-15

    This work investigates the use of neural networks in modeling the rejection processes of organic compounds (neutral and ionic) by nanofiltration and reverse osmosis membranes. Three feed-forward neural network (NN) models, characterized by a similar structure (eleven neurons for NN1 and NN2 and twelve neurons for NN3 in the input layer, one hidden layer and one neuron in the output layer), are constructed with the aim of predicting the rejection of organic compounds (neutral and ionic). A set of 956 data points for NN1 and 701 data points for NN2 and NN3 were used to test the neural networks. 80%, 10%, and 10% of the total data were used, respectively, for the training, the validation, and the test of the three models. For the most promising neural network models, the predicted rejection values of the test dataset were compared to measured rejections values; good correlations were found (R= 0.9128 for NN1, R=0.9419 for NN2, and R=0.9527 for NN3). The root mean squared errors for the total dataset were 11.2430% for NN1, 9.0742% for NN2, and 8.2047% for NN3. Furthermore, the comparison between the predicted results and QSAR models shows that the neural network models gave far better.

  5. Prediction of the rejection of organic compounds (neutral and ionic) by nanofiltration and reverse osmosis membranes using neural networks

    International Nuclear Information System (INIS)

    Ammi, Yamina; Khaouane, Latifa; Hanini, Salah

    2015-01-01

    This work investigates the use of neural networks in modeling the rejection processes of organic compounds (neutral and ionic) by nanofiltration and reverse osmosis membranes. Three feed-forward neural network (NN) models, characterized by a similar structure (eleven neurons for NN1 and NN2 and twelve neurons for NN3 in the input layer, one hidden layer and one neuron in the output layer), are constructed with the aim of predicting the rejection of organic compounds (neutral and ionic). A set of 956 data points for NN1 and 701 data points for NN2 and NN3 were used to test the neural networks. 80%, 10%, and 10% of the total data were used, respectively, for the training, the validation, and the test of the three models. For the most promising neural network models, the predicted rejection values of the test dataset were compared to measured rejections values; good correlations were found (R= 0.9128 for NN1, R=0.9419 for NN2, and R=0.9527 for NN3). The root mean squared errors for the total dataset were 11.2430% for NN1, 9.0742% for NN2, and 8.2047% for NN3. Furthermore, the comparison between the predicted results and QSAR models shows that the neural network models gave far better.

  6. Ultrafiltration and nanofiltration membrane fouling by natural organic matter: Mechanisms and mitigation by pre-ozonation and pH.

    Science.gov (United States)

    Yu, Wenzheng; Liu, Teng; Crawshaw, John; Liu, Ting; Graham, Nigel

    2018-08-01

    The fouling of ultrafiltration (UF) and nanofiltration (NF) membranes during the treatment of surface waters continues to be of concern and the particular role of natural organic matter (NOM) requires further investigation. In this study the effect of pH and surface charge on membrane fouling during the treatment of samples of a representative surface water (Hyde Park recreational lake) were evaluated, together with the impact of pre-ozonation. While biopolymers in the surface water could be removed by the UF membrane, smaller molecular weight (MW) fractions of NOM were poorly removed, confirming the importance of membrane pore size. For NF membranes the removal of smaller MW fractions (800 Da-10 kDa) was less than expected from their pore size; however, nearly all of the hydrophobic, humic-type substances could be removed by the hydrophilic NF membranes for all MW distributions (greater than 90%). The results indicated the importance of the charge and hydrophilic nature of the NOM. Thus, the hydrophilic NF membrane could remove the hydrophobic organic matter, but not the hydrophilic substances. Increasing charge effects (more negative zeta potentials) with increasing solution pH were found to enhance organics removal and reduce fouling (flux decline), most likely through greater membrane surface repulsion. Pre-ozonation of the surface water increased the hydrophilic fraction and anionic charge of NOM and altered their size distributions. This resulted in a decreased fouling (less flux decline) for the UF and smaller pore NF, but a slight increase in fouling for the larger pore NF. The differences in the NF behavior are believed to relate to the relative sizes of ozonated organic fractions and the NF pores; a similar size of ozonated organic fractions and the NF pores causes significant membrane fouling. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Nanofiltration and Tight Ultrafiltration Membranes for Natural Organic Matter Removal-Contribution of Fouling and Concentration Polarization to Filtration Resistance.

    Science.gov (United States)

    Winter, Joerg; Barbeau, Benoit; Bérubé, Pierre

    2017-07-02

    Nanofiltration (NF) and tight ultrafiltration (tight UF) membranes are a viable treatment option for high quality drinking water production from sources with high concentrations of contaminants. To date, there is limited knowledge regarding the contribution of concentration polarization (CP) and fouling to the increase in resistance during filtration of natural organic matter (NOM) with NF and tight UF. Filtration tests were conducted with NF and tight UF membranes with molecular weight cut offs (MWCOs) of 300, 2000 and 8000 Da, and model raw waters containing different constituents of NOM. When filtering model raw waters containing high concentrations of polysaccharides (i.e., higher molecular weight NOM), the increase in resistance was dominated by fouling. When filtering model raw waters containing humic substances (i.e., lower molecular weight NOM), the increase in filtration resistance was dominated by CP. The results indicate that low MWCO membranes are better suited for NOM removal, because most of the NOM in surface waters consist mainly of humic substances, which were only effectively rejected by the lower MWCO membranes. However, when humic substances are effectively rejected, CP can become extensive, leading to a significant increase in filtration resistance by the formation of a cake/gel layer at the membrane surface. For this reason, cross-flow operation, which reduces CP, is recommended.

  8. Nanofiltration and Tight Ultrafiltration Membranes for Natural Organic Matter Removal—Contribution of Fouling and Concentration Polarization to Filtration Resistance

    Directory of Open Access Journals (Sweden)

    Joerg Winter

    2017-07-01

    Full Text Available Nanofiltration (NF and tight ultrafiltration (tight UF membranes are a viable treatment option for high quality drinking water production from sources with high concentrations of contaminants. To date, there is limited knowledge regarding the contribution of concentration polarization (CP and fouling to the increase in resistance during filtration of natural organic matter (NOM with NF and tight UF. Filtration tests were conducted with NF and tight UF membranes with molecular weight cut offs (MWCOs of 300, 2000 and 8000 Da, and model raw waters containing different constituents of NOM. When filtering model raw waters containing high concentrations of polysaccharides (i.e., higher molecular weight NOM, the increase in resistance was dominated by fouling. When filtering model raw waters containing humic substances (i.e., lower molecular weight NOM, the increase in filtration resistance was dominated by CP. The results indicate that low MWCO membranes are better suited for NOM removal, because most of the NOM in surface waters consist mainly of humic substances, which were only effectively rejected by the lower MWCO membranes. However, when humic substances are effectively rejected, CP can become extensive, leading to a significant increase in filtration resistance by the formation of a cake/gel layer at the membrane surface. For this reason, cross-flow operation, which reduces CP, is recommended.

  9. Organic Solvent Tropical Report [SEC 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    COWLEY, W.L.

    2000-06-21

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines.

  10. Factors affecting fluoride and natural organic matter (NOM) removal from natural waters in Tanzania by nanofiltration/reverse osmosis.

    Science.gov (United States)

    Shen, Junjie; Schäfer, Andrea I

    2015-09-15

    This study examined the feasibility of nanofiltration (NF) and reverse osmosis (RO) in treating challenging natural tropical waters containing high fluoride and natural organic matter (NOM). A total of 166 water samples were collected from 120 sources within northern Tanzania over a period of 16 months. Chemical analysis showed that 81% of the samples have fluoride levels exceeding the WHO drinking guideline of 1.5mg/L. The highest fluoride levels were detected in waters characterized by high ionic strength, high inorganic carbon and on some occasions high total organic carbon (TOC) concentrations. Bench-scale experiments with 22 representative waters (selected based on fluoride concentration, salinity, origin and in some instances organic matter) and 6 NF/RO membranes revealed that ionic strength and recovery affected fluoride retention and permeate flux. This is predominantly due to osmotic pressure and hence the variation of diffusion/convection contributes to fluoride transport. Different membranes had distinct fluoride removal capacities, showing different raw water concentration treatability limits regarding the WHO guideline compliance. BW30, BW30-LE and NF90 membranes had a feed concentration limit of 30-40 mg/L at 50% recovery. NOM retention was independent of water matrices but is governed predominantly by size exclusion. NOM was observed to have a positive impact on fluoride removal. Several mechanisms could contribute but further studies are required before a conclusion could be drawn. In summary, NF/RO membranes were proved to remove both fluoride and NOM reliably even from the most challenging Tanzanian waters, increasing the available drinking water sources. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. 40 CFR 52.254 - Organic solvent usage.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Organic solvent usage. 52.254 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.254 Organic solvent usage. (a) This... (d) of this section and the architectural coatings and solvent disposal emission limitations...

  12. Thin porphyrin composite membranes with enhanced organic solvent transport

    KAUST Repository

    Phuoc, Duong; Anjum, Dalaver H.; Peinemann, Klaus-Viktor; Nunes, Suzana Pereira

    2018-01-01

    Extending the stability of polymeric membranes in organic solvents is important for applications in chemical and pharmaceutical industry. Thin-film composite membranes with enhanced solvent permeance are proposed, using porphyrin as a building block

  13. NOVEL POLYMERIC MEMBRANE FOR DEHYDRATION OF ORGANIC SOLVENTS

    Science.gov (United States)

    Pervaporation has emerged as an economically viable alternative technology for dehydration of organic solvents, removal of organic compounds and organic/organic separations. Development of a membrane system with suitable flux and selectivity characteristics plays a critical role...

  14. Enhanced performance of dicationic ionic liquid electrolytes by organic solvents

    International Nuclear Information System (INIS)

    Li, Song; Feng, Guang; Cummings Peter, T; Zhang, Pengfei; Fulvio Pasquale, F; Hillesheim Patrick, C; Dai, Sheng

    2014-01-01

    The use of dicationic ionic liquid (DIL) electrolytes in supercapacitors is impeded by the slow dynamics of DILs, whereas the addition of organic solvents into DIL electrolytes improves ion transport and then enhances the power density of supercapacitors. In this work, the influences of organic solvents on the conductivity of DILs and the electrical double layer (EDL) of DIL-based supercapacitors are investigated using classical molecular dynamics simulation. Two types of organic solvents, acetonitrile (ACN) and propylene carbonate (PC), were used to explore the effects of different organic solvents on the EDL structure and capacitance of DIL/organic solvent-based supercapacitors. Firstly, it was found that the conductivity of DIL electrolytes was greatly enhanced in the presence of the organic solvent ACN. Secondly, a stronger adsorption of PC on graphite results in different EDL structures formed by DIL/ACN and DIL/PC electrolytes. The expulsion of co-ions from EDLs was observed in DIL/organic solvent electrolytes rather than neat DILs and this feature is more evident in DIL/PC. Furthermore, the bell-shaped differential capacitance–electric potential curve was not essentially changed by the presence of organic solvents. Comparing DIL/organic solvent electrolytes with neat DILs, the capacitance is slightly increased by organic solvents, which is in agreement with experimental observation. (paper)

  15. Adsorbents for radioactive organic solvent wastes

    International Nuclear Information System (INIS)

    Ichinose, Shigeo; Kiribayashi, Takehiko.

    1986-01-01

    Purpose: To enable to settle radioactive solvents such as tributyl phosphate (TBP) and n-dodecane as they are without using hydrophobicizing agent such as quaternary ammonium salts. Constitution: The adsorbents are prepared by replacing interlaminer ions of swelling-type synthetic mica with alkaline earth metals or metal ions. For instance, synthetic micas introduced with Zr 4+ or Ca 2+ between the layers provide quite different functions from those of starting materials due to the properties of ions introduced between the layers. That is, they provide an intense affinity to organic phosphates such as TBP and transform into material showing a property of adsorbing and absorbing them. Particularly, the fixing nature to the phosphor content constituting TBP is significantly increased. (Horiuchi, T.)

  16. Rejection of Emerging Organic Contaminants by Nanofiltration and Reverse Osmosis Membranes: Effects of Fouling, Modelling and Water Reuse

    OpenAIRE

    Yangali Quintanilla, V.

    2010-01-01

    The book contains a description of the presence of micropollutants (medicines, hormones, pesticides) in surface water and shows that conventional water treatment poorly removes micropollutants. Nanofiltration and reverse osmosis are more appropriate technologies; however removals can vary depending on the properties of compounds and types of membranes. Thus, quantification of removals is studied by means of multivariate data analysis techniques and more understanding of the separation of micr...

  17. Proposing nanofiltration as acceptable barrier for organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor; Maeng, Sungkyu; Fujioka, Takahiro; Kennedy, Maria Dolores; Amy, Gary L.

    2010-01-01

    . The use of RO in existing water reuse facilities is addressed and questioned, taking into consideration that tight NF can be a more cost-effective and efficient technology to target the problem of organic contaminants. It was concluded that tight NF

  18. Measurement of oxygen transfer from air into organic solvents

    DEFF Research Database (Denmark)

    Ramesh, Hemalata; Mayr, Torsten; Hobisch, Mathias

    2016-01-01

    biological reactions require the supply of oxygen, most normally from air. However, reliable on-line measurements of oxygen concentration in organic solvents (and hence oxygen transfer rates from air to the solvent) has to date proven impossible due limitations in the current analytical methods. Results...... applications). Subsequently, we measured the oxygen transfer rates from air into these organic solvents. Conclusion The measurement of oxygen transfer rates from air into organic solvents using the dynamic method was established using the solvent resistant optical sensor. The feasibility of online oxygen...... For the first time, we demonstrate on-line oxygen measurements in non-aqueous media using a novel optical sensor. The sensor was used to measure oxygen concentration in various organic solvents including toluene, THF, isooctane, DMF, heptane and hexane (which have all been shown suitable for several biological...

  19. 40 CFR Table 5 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the.... Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic HAP, percent by mass 1...

  20. 40 CFR Table 3 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent by mass 1...

  1. 40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction... formulation data. Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent...

  2. Nanofiltration vs. reverse osmosis for the removal of emerging organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2011-10-01

    Reverse osmosis (RO) in existing water reuse facilities is a water industry standard. However, that approach may be questioned taking into consideration that "tight" NF can be equal or "better" than RO. NF can achieve the same removals of RO membranes when dealing with emerging organic contaminants (pharmaceuticals, pesticides, endocrine disruptors and others). Experiments using 18 emerging contaminants were performed using membranes NF200 and NF90 at bench-scale units, and for a more complete study, results of NF and RO pilot and full-scale experiments where compared to our experimental results. The removal results showed that NF can remove many emerging contaminants. The average removal by tight NF was 82% for neutral contaminants and 97% for ionic contaminants. The average removal by RO was 85% for neutral contaminants and 99% for ionic contaminants. Aquifer recharge and recovery (ARR) followed by NF can effectively remove emerging contaminants with removals over 90% when loose NF membranes are used.

  3. Nanofiltration vs. reverse osmosis for the removal of emerging organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2011-01-01

    Reverse osmosis (RO) in existing water reuse facilities is a water industry standard. However, that approach may be questioned taking into consideration that "tight" NF can be equal or "better" than RO. NF can achieve the same removals of RO membranes when dealing with emerging organic contaminants (pharmaceuticals, pesticides, endocrine disruptors and others). Experiments using 18 emerging contaminants were performed using membranes NF200 and NF90 at bench-scale units, and for a more complete study, results of NF and RO pilot and fullscale experiments where compared to our experimental results. The removal results showed that NF can remove many emerging contaminants. The average removal by tight NF was 82% for neutral contaminants and 97% for ionic contaminants. The average removal by RO was 85% for neutral contaminants and 99% for ionic contaminants. Aquifer recharge and recovery (ARR) followed by NF can effectively remove emerging contaminants with removals over 90% when loose NF membranes are used. © 2011 2011 Desalination Publications. All rights reserved.

  4. Substitution of Organic Solvents in Selected Industrial Cleaning Processes

    DEFF Research Database (Denmark)

    Jacobsen, Thomas; Rasmussen, Pia Brunn

    1997-01-01

    Volatile organic solvents (VOC)are becoming increasingly unwanted in industrial processes. Substitution of VOC with non-volatile, low-toxic compounds is a possibility to reduce VOC-use. It has been successfully demonstrated, that organic solvents used in cleaning processes in sheet offset printing...

  5. Uranium extraction from colofanite via organic solvents

    International Nuclear Information System (INIS)

    Ribeiro, Valeria Aparecida Leitao

    2007-01-01

    This work describes the use of pure or combined extractants dissolved in organic solvents for quantitative uranium recovery from colofanite, a fluoroapatite ore, from Itataia, Santa Quiteria, Ceara, Brazil. This ore contains the highest brazilian uranium reserve. The metal is associated to phosphate species. The ore is digested with sulfuric acid (wet process), producing phosphoric acid, which is used for manufacturing of fertilizers and animal food. >From the acid leaching, some systems for uranium recovery were tested. Among them, PC88A (2-ethyl-hexyl phosphonic acid, mono-2-ethyl-hexyl ester) 40% vol. and DEHPA (di(2-ethyl-hexyl)phosphoric acid) 40% vol. in kerosene presented the highest values for the distribution coefficient (D) for uranium. When synergistic systems were employed, the best results were obtained for DEHPA 40%vol. + PC88A 40%vol. and DEHPA 40% vol. + TOPO (trioctylphosphine oxide) 5% vol. in kerosene. 15% wt/v sodium carbonate was the best medium for uranium stripping and separation from iron, the main interfering element. Uranium was precipitated as sodium diuranate by adding sodium hydroxide (5,0 mol L -1 ). Thorium in the raffinate was extracted by TOPO (0,1% vol.) in cyclohexane. The radioactivity level of the final aqueous waste is similar to natural background, according to CNEN-NE 6.05 Norm. After neutralization, the solid can be co-processed, according to the Directory 264 from the National Brazilian Environmental Council (CONAMA), whereas the treated effluent can be discarded according to the Directory 357 from CONAMA. (author)

  6. [Analyze nanofiltration separation rule of chlorogenic acid from low concentration ethanol by Donnan effect and solution-diffusion effect].

    Science.gov (United States)

    Li, Cun-Yu; Liu, Li-Cheng; Jin, Li-Yang; Li, Hong-Yang; Peng, Guo-Ping

    2017-07-01

    To separate chlorogenic acid from low concentration ethanol and explore the influence of Donnan effect and solution-diffusion effect on the nanofiltration separation rule. The experiment showed that solution pH and ethanol volume percent had influences on the separation of chlorogenic acid. Within the pH values from 3 to 7 for chlorogenic acid in 30% ethanol, the rejection rate of chlorogenic acid was changed by 70.27%. Through the response surface method for quadratic regression model, an interaction had been found in molecule weight cut-off, pH and ethanol volume percent. In fixed nanofiltration apparatus, the existence states of chlorogenic acid determinedits separation rules. With the increase of ethanol concentration, the free form chlorogenic acid was easily adsorbed, dissolved on membrane surface and then caused high transmittance due to the solution-diffusion effect. However, at the same time, due to the double effects of Donnan effect and solution-diffusion effect, the ionic state of chlorogenic acid was hard to be adsorbed in membrane surface and thus caused high rejection rate. The combination of Box-Behnken design and response surface analysis can well optimize the concentrate process by nanofiltration, and the results showed that nanofiltration had several big advantages over the traditional vacuum concentrate technology, meanwhile, and solved the problems of low efficiency and serious component lossesin the Chinese medicines separation process for low concentration organic solvent-water solution. Copyright© by the Chinese Pharmaceutical Association.

  7. The Solvent Selection framework: solvents for organic synthesis, separation processes and ionic-organic synthesis

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Sansonetti, Sascha; Abildskov, Jens

    2012-01-01

    This paper presents a systematic integrated framework for solvent selection and solvent design. The framework is divided into several modules, which can tackle specific problems in various solvent-based applications. In particular, three modules corresponding to the following solvent selection pr...

  8. Psychomotor Effects of Mixed Organic Solvents on Rubber Workers

    Directory of Open Access Journals (Sweden)

    O Aminian

    2014-04-01

    Full Text Available Background: Exposure to organic solvents is common among workers. Objective: To assess neurobehavioral effects of long-term exposure to organic solvents among rubber workers in Tehran, Iran. Methods: Across-sectional study was conducted on 223 employees of a rubber industry. The participants completed a data collection sheet on their occupational and medical history, and demographic characteristics including age, work experience, education level; they performed 6 psychiatric tests on the neurobehavioral core test battery (NCTB that measure simple reaction time, short-term memory (digit span, Benton, eye-hand coordination (Purdue pegboard, pursuit aiming, and perceptual speed (digit symbol. Results: Workers exposed and not exposed to organic solvents had similar age and education distribution. The mean work experience of the exposed and non-exposed workers was 5.9 and 4.4 years, respectively. The exposed workers had a lower performance compared to non-exposed workers in all psychomotor tests. After controlling for the confounders by logistic regression analysis, it was found that exposure to organic solvents had a significant effect on the results of digit symbols, digit span, Benton, aiming, and simple reaction time tests. No significant effect was observed in pegboard test. Conclusion: Occupational exposure to organic solvent can induce subtle neurobehavioral changes among workers exposed to organic solvents; therefore, periodical evaluation of the central nervous system by objective psychomotor tests is recommended among those who are chronically exposed to organic solvents.

  9. Occupational exposure to organic solvents and sleep-disordered breathing.

    Science.gov (United States)

    Ulfberg, J; Carter, N; Talbäck, M; Edling, C

    1997-01-01

    To investigate whether people with occupational exposure to organic solvents have a higher prevalence of obstructive sleep apnea syndrome (OSAS) than the general population and to examine the relationship between snoring and exposure to organic solvents. Consecutive patients, aged 30-64 years, referred during a 3-year period to the sleep laboratory at Avesta Hospital, Sweden, because of suspected OSAS made up the patient groups. Following admission, patients underwent a simplified sleep apnea investigation and were divided into two groups, OSAS (n = 320) and snorers (n = 443). A random sample of 296 men and 289 women aged 30-64 years obtained from a register of all country residents maintained by the county tax authority served as referents (controls). Both patients and referents responded to two questionnaires, including questions about occupation, exposure to organic solvents, and other chemical and physical agents. Men with OSAS or snoring and women with snoring had more often been occupationally exposed to organic solvents than the referents, showing an almost twofold increase in risk for those exposed during whole workdays. For men, the risk of OSAS or snoring increased with increasing exposure. The result indicates that occupational exposure to organic solvents might cause sleep apnea. A new observation is that even snoring could be caused by exposure to organic solvents. It is important to elucidate whether exposure to organic solvents is a cause of OSAS, because such a finding may have important implications for prevention and treatment of sleep disturbances.

  10. Method for Selection of Solvents for Promotion of Organic Reactions

    DEFF Research Database (Denmark)

    Gani, Rafiqul; Jiménez-González, Concepción; Constable, David J.C.

    2005-01-01

    is to produce, for a given reaction, a short list of chemicals that could be considered as potential solvents, to evaluate their performance in the reacting system, and, based on this, to rank them according to a scoring system. Several examples of application are given to illustrate the main features and steps......A method to select appropriate green solvents for the promotion of a class of organic reactions has been developed. The method combines knowledge from industrial practice and physical insights with computer-aided property estimation tools for selection/design of solvents. In particular, it employs...... estimates of thermodynamic properties to generate a knowledge base of reaction, solvent and environment related properties that directly or indirectly influence the rate and/or conversion of a given reaction. Solvents are selected using a rules-based procedure where the estimated reaction-solvent properties...

  11. 40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass fraction...

  12. 40 CFR Table 3 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction.... If a solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass...

  13. Investigations of the Effects of Biocide Dosing and Chemical Cleaning on the Organic Carbon Removal in an Integrated Ultrafiltration - Nanofiltration Desalination Pilot Plant

    KAUST Repository

    Khojah, Bayan A.

    2017-12-01

    Membrane desalination has become one of the most important desalination technologies used in the world. It provides high water quality for numerous applications and it demonstrates excellent desalination efficiency. One of the most troubling drawbacks of membrane desalination is membrane fouling. It decreases the performance of the membranes and increases the energy requirement. Two of the most important causes of fouling are microbes and organic matter. Hence, to maintain an optimized desalination performance, routine inspection of microbial and organic contents of water is crucial for desalination plants. In this study, water samples were obtained from different treatment points in an ultrafiltration (UF)/nanofiltration (NF) seawater desalination pilot plant. This was performed to better understand how the water quality changes along the desalination scheme. The effect of fouling control techniques, including Chemically Enhanced Backwash (CEB), Cleaning in Place (CIP), and the addition of a biocide (DBNPA) was studied. Different analytical tools were applied, including Bactiquant, Total Organic Carbon (TOC), Assimilable Organic Carbon (AOC), and Liquid Chromatography for Organic Carbon Detection (LC-OCD). Out results showed that UF did not decrease TOC but it was sufficient in removing up to 99.7% of bacteria. Nanofiltration, removed up to 95% of TOC. However, NF permeate had a high increase in AOC as compared to the raw seawater sample. The LC-OCD results suggested that this might be due to the increased low molecular weight neutrals which were the most common organic species in the NF permeate. The fouling control techniques showed various effects on the desalination efficiency. Daily CEB did not cause a reduction in TOC or bacteria but decreased AOC in the UF filtrate. The biocide addition resulted in an adequate membranes protection from fouling and it did not affect the investigated water parameters. When the dosing of biocide was stopped, the water quality

  14. Background Noise Contributes to Organic Solvent Induced Brain Dysfunction

    Directory of Open Access Journals (Sweden)

    O’neil W. Guthrie

    2016-01-01

    Full Text Available Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures.

  15. Background Noise Contributes to Organic Solvent Induced Brain Dysfunction

    Science.gov (United States)

    Guthrie, O'neil W.; Wong, Brian A.; McInturf, Shawn M.; Reboulet, James E.; Ortiz, Pedro A.; Mattie, David R.

    2016-01-01

    Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures. PMID:26885406

  16. Background Noise Contributes to Organic Solvent Induced Brain Dysfunction.

    Science.gov (United States)

    Guthrie, O'neil W; Wong, Brian A; McInturf, Shawn M; Reboulet, James E; Ortiz, Pedro A; Mattie, David R

    2016-01-01

    Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures.

  17. Solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents

    International Nuclear Information System (INIS)

    Fan, Jie-Ping; Yang, Dan; Xu, Xiao-Kang; Guo, Xiao-Jie; Zhang, Xue-Hong

    2015-01-01

    Highlights: • The solubilities of daidzin were measured in various solvents. • The solubility data were correlated by three models. • The thermodynamic properties of the dissolution process were also determined. - Abstract: The solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents was measured by high performance liquid chromatography (HPLC) analysis method from T = (283.2 to 323.2) K at atmosphere pressure. The results show that at higher temperature more daidzin dissolves, and moreover, the solubility increases with the ethyl alcohol mole fraction increase in the (ethyl alcohol + water) mixed solvents. The experimental solubility values were correlated by a simplified thermodynamic equation, λh equation and modified Apelblat equation. Based on the solubility of daidzin, the enthalpy and entropy of solution were also evaluated by van’t Hoff equation. The results illustrated that the dissolution process of daidzin is endothermic and entropy driven

  18. Removal of dissolved organic matter in municipal effluent with ozonation, slow sand filtration and nanofiltration as high quality pre-treatment option for artificial groundwater recharge.

    Science.gov (United States)

    Linlin, Wu; Xuan, Zhao; Meng, Zhang

    2011-04-01

    In the paper the combination process of ozonation, slow sand filtration (SSF) and nanofiltration (NF) was investigated with respect to dissolved organic matter (DOM) removal as high quality pre-treatment option for artificial groundwater recharge. With the help of ozonation leading to breakdown of the large organic molecules, SSF preferentially removes soluble microbial by-product-like substances and DOM with molecular weight (MW) less than 1.0 kDa. NF, however, removes aromatic, humic acid-like and fulvic acid-like substances efficiently and specially removes DOM with MW above 1.0 kDa. The residual DOM of the membrane permeate is dominated by small organics with MW 500 Da, which can be further reduced by the aquifer treatment, despite of the very low concentration. Consequently, the O(3)/SSF/NF system offers a complementary process in DOM removal. Dissolved organic carbon (DOC) and trihalomethane formation potential (THMFP) can be reduced from 6.5±1.1 to 0.7±0.3 mg L(-1) and from 267±24 to 52±6 μg L(-1), respectively. The very low DOC concentration of 0.6±0.2 mg L(-1) and THMFP of 44±4 μg L(-1) can be reached after the aquifer treatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Removal of refractory organics in nanofiltration concentrates of municipal solid waste leachate treatment plants by combined Fenton oxidative-coagulation with photo--Fenton processes.

    Science.gov (United States)

    Li, Jiuyi; Zhao, Lei; Qin, Lele; Tian, Xiujun; Wang, Aimin; Zhou, Yanmei; Meng, Liao; Chen, Yong

    2016-03-01

    Removal of the refractory organic matters in leachate brines generated from nanofiltration unit in two full-scale municipal solid waste landfill leachate treatment plants was investigated by Fenton oxidative-coagulation and ultraviolet photo - Fenton processes in this study. Fenton oxidative-coagulation was performed under the condition of an initial pH of 5.0 and low H2O2/Fe(2+) ratios. After precipitate separation, the remaining organic constituents were further oxidized by photo - Fenton process. For both leachate brines with varying pollution strength, more than 90% COD and TOC reductions were achieved at H2O2/Fe(2+) dosages of 35 mM/8 mM and 90 mM/10 mM, respectively. The effluent COD ranged 120-160 mg/L under the optimal operating conditions, and the biodegradability was increased significantly. Fenton oxidative-coagulation was demonstrated to contribute nearly 70% overall removal of organic matters. In the combined processes, the efficiency of hydrogen peroxide varied from 216 to 228%, which may significantly reduce the operating cost of conventional Fenton method. Six phthalic acid esters and thirteen polycyclic aromatic hydrocarbons were found in leachate brines, and, on the average, around 80% phthalic acid esters and 90% polycyclic aromatic hydrocarbons were removed by the combined treatments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Alternatives to Organic Solvents in Industrial Cleaning Processes

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    1998-01-01

    To control chemical hazards in work places, substitution of harmful substances with less harmful or non-toxic products is now a method used in many countries and in many companies. It has previously been demonstrated that it is desirable and possible to use non-volatile, low-toxic vegetable...... cleaning agents in offset printing companies instead of volatile, toxic organic solvents. The present study is based on a project with the aim of defining other industrial processes, where organic solvents used for cleaning or degreasing can be replaced by non-volatile, low-toxic products, which are based...... on esters from fatty acids of vegetable origin (vegetable esters - VE).The study indicates that industrial cleaning/degreasing with organic solvents may be substituted with VEs on metal surfaces and on some coated surfaces, in manufacture of paints and inks, use of paints, use of inks (printing), metal...

  1. Phase Behavior of Mixtures of Ionic Liquids and Organic Solvents

    DEFF Research Database (Denmark)

    Abildskov, Jens; Ellegaard, Martin Dela; O’Connell, J.P.

    2010-01-01

    A corresponding-states form of the generalized van der Waals equation, previously developed for mixtures of an ionic liquid and a supercritical solute, is here extended to mixtures including an ionic liquid and a solvent (water or organic). Group contributions to characteristic parameters...... are implemented, leading to an entirely predictive method for densities of mixed compressed ionic liquids. Quantitative agreement with experimental data is obtained over wide ranges of conditions. Previously, the method has been applied to solubilities of sparingly soluble gases in ionic liquids and in organic...... solvents. Here we show results for heavier and more-than-sparingly solutes such as carbon dioxide and propane in ionic liquids....

  2. Linear correlation of interfacial tension at water-solvent interface, solubility of water in organic solvents, and SE* scale parameters

    International Nuclear Information System (INIS)

    Mezhov, E.A.; Khananashvili, N.L.; Shmidt, V.S.

    1988-01-01

    A linear correlation has been established between the solubility of water in water-immiscible organic solvents and the interfacial tension at the water-solvent interface on the one hand and the parameters of the SE* and π* scales for these solvents on the other hand. This allows us, using the known tabulated SE* or π* parameters for each solvent, to predict the values of the interfacial tension and the solubility of water for the corresponding systems. We have shown that the SE* scale allows us to predict these values more accurately than other known solvent scales, since in contrast to other scales it characterizes solvents found in equilibrium with water

  3. 40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Contents of... Manufacturing Pt. 63, Subpt. VVVV, Table 5 Table 5 to Subpart VVVV of Part 63—Default Organic HAP Contents of Solvents and Solvent Blends As specified in § 63.5758(a)(6), when detailed organic HAP content data for...

  4. Dissolution of covalent adaptable network polymers in organic solvent

    Science.gov (United States)

    Yu, Kai; Yang, Hua; Dao, Binh H.; Shi, Qian; Yakacki, Christopher M.

    2017-12-01

    It was recently reported that thermosetting polymers can be fully dissolved in a proper organic solvent utilizing a bond-exchange reaction (BER), where small molecules diffuse into the polymer, break the long polymer chains into short segments, and eventually dissolve the network when sufficient solvent is provided. The solvent-assisted dissolution approach was applied to fully recycle thermosets and their fiber composites. This paper presents the first multi-scale modeling framework to predict the dissolution kinetics and mechanics of thermosets in organic solvent. The model connects the micro-scale network dynamics with macro-scale material properties: in the micro-scale, a model is developed based on the kinetics of BERs to describe the cleavage rate of polymer chains and evolution of chain segment length during the dissolution. The micro-scale model is then fed into a continuum-level model with considerations of the transportation of solvent molecules and chain segments in the system. The model shows good prediction on conversion rate of functional groups, degradation of network mechanical properties, and dissolution rate of thermosets during the dissolution. It identifies the underlying kinetic factors governing the dissolution process, and reveals the influence of different material and processing variables on the dissolution process, such as time, temperature, catalyst concentration, and chain length between cross-links.

  5. Production of thermostable and organic solvent-tolerant alkaline ...

    African Journals Online (AJOL)

    An alkaliphilic bacterium producing organic solvent-tolerant and thermostable alkaline protease was isolated from poultry litter site and identified as Bacillus coagulans PSB-07. Protease production under different submerged fermentation conditions were investigated with the aim of optimizing yield of enzyme. B. coagulans ...

  6. Characteristics of peaks of inhalation exposure to organic solvents

    NARCIS (Netherlands)

    Preller, L.; Burstyn, I.; Pater, N. de; Kromhout, H.

    2004-01-01

    Objectives: To determine which exposure metrics are sufficient to characterize 'peak' inhalation exposure to organic solvents (OS) during spraying operations. Methods: Personal exposure measurements (n = 27; duration 5-159 min) were collected during application of paints, primers, resins and glues

  7. Organic Synthesis under Solvent-free Condition. An Environmentally ...

    Indian Academy of Sciences (India)

    Though it is a common practice to run the organic reactions in solvent media, the ... this concept is simple. That is, the ... to vigorous research activity and reinvestigation of known reac- tions to achieve ... experimental procedure, work up technique and saving in labour. These would be ... This is true not only of the crystals of ...

  8. Molecular transport behaviour of organic solvents through halloysite ...

    Indian Academy of Sciences (India)

    Micro and Nano Materials Laboratory, Department of Chemistry, Institute of Technical ... The transport behaviour of three organic solvents (benzene, toluene and xylene) through halloysite nan- ... ena play important roles in different areas of engineering and ... their blends by an equilibrium swelling method has been.

  9. Antifeedant Activty Of Different Organic Solvent Crude Extracts Of ...

    African Journals Online (AJOL)

    The antifeedant activity of different organic solvents (acetone, carbon tetrachloride, chloroform, diethyl ether and ethyl alcohol) crude extracts of latex of Euphorbia hirta (family Euphobiaceae) against Limicolaria aurora was investigated, and compared with a control, using pawpaw, (Carica papaya) as bait, at a concentration ...

  10. Solvent extraction of thorium(IV) with dibutyldithiophosphoric acid in various organic solvents

    International Nuclear Information System (INIS)

    Curtui, M.; Haiduc, I.

    1994-01-01

    The extraction of thorium(IV) from perchlorate solutions with di-n-butyldithiophosphoric acid (HBudtp) in various organic solvents occurs through an ion exchange mechanism. The extracted species in the organic phase is an eight-coordinate complex Th(Budtp) 4 . The higher values of the distribution ratio obtained in HBudtp-benzene-water system than in HBudtp-n-butanol-water system are explained by higher solubility of the complex species in nonpolar solvents. The position of the extraction curves in the pH-range lower than 0.7 reduces the complexation of thorium(IV) with Budtp - in the aqueous phase and also the hydrolysis process. (author) 8 refs.; 4 figs.; 1 tab

  11. A solvent/non-solvent system for achieving solution-processed multilayer organic light-emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yue; Wu, Zhaoxin, E-mail: zhaoxinwu@mail.xjtu.edu.cn; He, Lin; Jiao, Bo; Hou, Xun

    2015-08-31

    We developed a solvent/non-solvent system to fabricate the multilayer organic light-emitting devices (OLEDs) based on poly(N-vinylcarbazole) (PVK) by solution-process. This solvent system consists of both the solvent and non-solvent of PVK, in which fluorescent small molecules could be fully dissolved and directly spin-coated on top of the PVK layer; it could effectively avoid the redissolution of PVK during the spin-coating process of small molecules emitting layer. In the further investigation of this system, we also demonstrated the three-component solvent system, and found out that the third component, a less volatile solvent of PVK, was crucial for preparing a smoother interface between PVK and emitting layer. Compared with OLEDs through the vacuum deposition, the devices fabricated by solution-process from the solvent/non-solvent system showed comparable efficiency, which indicate that the solvent/non-solvent system can be used as an alternative process to prepare the polymer and small molecule multilayer devices through all-solution-process. - Highlights: • We fabricate the multilayer OLEDs by solution-process using a novel system. • We develop a solvent/non-solvent system of polymer (PVK) to avoid redissolution. • Small molecules could be fully dissolved and directly spin-coated on PVK layer. • The devices fabricated by the system and vacuum deposition show comparable efficiency.

  12. Impact of solvent extraction organics on bioleaching by Acidithiobacillus ferrooxidans

    Science.gov (United States)

    Yu, Hualong; Liu, Xiaorong; Shen, Junhui; Chi, Daojie

    2017-03-01

    Solvent extraction organics (SX organics) entrained and dissoluted in the raffinate during copper SX operation, can impact bioleaching in case of raffinate recycling. The influence of SX organics on bioleaching process by Acidithiobacillus ferrooxidans (At. ferrooxidans) has been investigated. The results showed that, cells of At. ferrooxidans grew slower with contaminated low-grade chalcopyrite ores in shaken flasks bioleaching, the copper bioleaching efficiency reached 15%, lower than that of 24% for uncontaminated minerals. Obviously, the SX organics could adsorb on mineral surface and hinder its contact with bacterials, finanlly lead to the low bioleaching efficiency.

  13. Improving the organic and biological fouling resistance and removal of pharmaceutical and personal care products through nanofiltration by using in situ radical graft polymerization.

    Science.gov (United States)

    Lin, Yi-Li; Tsai, Chia-Cheng; Zheng, Nai-Yun

    2018-09-01

    In this study, an insitu radical graft polarization technique using monomers of 3-sulfopropyl methacrylate potassium salt (SPM) and 2-hydroxyethyl methacrylate (HEMA) was applied to a commercial nanofiltration membrane (NF90) to improve its removal of six commonly detected pharmaceutical and personal care products (PPCPs) and mitigate organic and biological fouling by humic acid (HA) and sodium alginate (SA). Compared with the virgin membrane, the modified NF90 membrane exhibited considerably improved fouling resistance and an increased reversible fouling percentage, especially for SA+HA composite fouling Moreover, the PPCP removal of the modified NF90 membrane was higher than that of the virgin membrane after SA and SA+HA fouling, respectively. Triclosan and carbamazepine, which are poorly rejected, could be effectively removed by modified membrane after SA or SA+HA fouling. Both monomers modified the membrane surface by increasing the hydrophilicity and decreasing the contact angle. The degree of grafting was quantified using attenuated total reflection Fourier-transform infrared spectroscopy. The mitigation in the fouling was evident from the low quantity of deposit formed on the modified membrane, as observed using scanning electron microscopy. A considerable amount of highly hydrophobic triclosan was adsorbed on the SA-fouled virgin membrane and penetrated through it. By contrast, the adsorption of triclosan was substantially lower in the SPM-modified membrane. After membrane modification, the fouling mechanism changed from solely intermediate blocking to both intermediate blocking and complete blocking after membrane modification. Thus, the in situ radical graft polymerization method effectively reduces organic and biological fouling and provides high PPCP removal, which is beneficial for fouling control and produces permeate of satisfactory quality for application in the field of membrane technology. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Sub-6 nm Thin Cross-Linked Dopamine Films with High Pressure Stability for Organic Solvent Nanofiltration

    KAUST Repository

    Perez Manriquez, Liliana; Behzad, Ali Reza; Peinemann, Klaus-Viktor

    2016-01-01

    Interfacial polymerization of dopamine and terephtaloyl chloride is performed on a porous crosslinked polyacrylonitrile support membrane. The resulting polymer layer has a smooth surface and is ultrathin (about 5 nm). The chemical nature

  15. Gold recovery from organic solvents using galvanic stripping

    Energy Technology Data Exchange (ETDEWEB)

    Flores, C.; O`Keefe, T.J. [Univ. of Missouri, Rolla, MO (United States). Dept. of Metallurgical Engineering

    1995-08-01

    A novel process using solid metals for the direct reduction of more noble metal ions from solvent extraction organics has been developed. Base metals recovery has been the principal focus of investigations to date but feasibility tests have now also been made on galvanically stripping selected precious metals. In this study gold (III) was loaded from an aqueous HAuCl{sub 4}{center_dot}3H{sub 2}O solution into a mixed organic 40 vol.% TBP, 10 vol.% D2EHPA in kerosene. The direct precipitation of metallic gold from the loaded organic phase using zinc powder and iron, aluminum and copper slabs at 70 C was successfully demonstrated. The gold reduction rates were relatively fast even though the conductivity of the organic solutions is very low. The reaction rates were studied as a function of the variables zinc particulate size, oxygen and nitrogen atmosphere, water content in the organic phase, organic ratios and temperature. The gold morphology was usually powdery or dendritic in nature but continuous films were obtained in some instances. Activation energies were calculated and possible reaction mechanisms are discussed. In general, the results obtained were very promising and showed that gold can be successfully cemented from selected organic solvents by galvanic stripping using less noble solid metal reductants.

  16. The use of organic solvents in mutagenicity testing.

    Science.gov (United States)

    Abbondandolo, A; Bonatti, S; Corsi, C; Corti, G; Fiorio, R; Leporini, C; Mazzaccaro, A; Nieri, R; Barale, R; Loprieno, N

    1980-10-01

    13 organic substances (dimethylsulfoxide, methanol, ethanol, n-propyl alcohol, sec-butyl alcohol, tert-butyl alcohol, dl-sec-amyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, 1,4-diethylene dioxide, acetone, methyl acetate and formamide) were considered from the standpoint of their use as solvents for water-insoluble chemicals to be tested for mutagenicity. First, the effect of these solvents on cell survival was studied in the yeast Schizosaccharomyces pombe and in V79 Chinese hamster cells. 8 solvents showing relatively low toxicity on either cell system (dimethylsulfoxide, ethanol, ethylene glycol, ethylene glycol monomethyl ether, 1,4-diethylene dioxide, acetone, methyl acetate and formamide) were tested for their effect on aminopyrine demethylase. 4 solvents (ethanol, 1,4-diethylene dioxide, methyl acetate and formamide) showed a more or less pronounced adverse effect on the microsomal enzymic activity. The remaining 4 and methanol (whose effect on aminopyrine demethylase was not testable) were assayed for mutagenicity in S. pombe. They all gave negative results both with and without the post-mitochondrial fraction from mouse liver.

  17. Solvent-resistant organic transistors and thermally stable organic photovoltaics based on cross-linkable conjugated polymers

    KAUST Repository

    Kim, Hyeongjun; Han, A. Reum; Cho, Chulhee; Kang, Hyunbum; Cho, Hanhee; Lee, Mooyeol; Frechet, Jean; Oh, Joonhak; Kim, Bumjoon

    2012-01-01

    organic electronics with air stability, solvent resistance, and thermal stability. Herein, we have developed a simple but powerful approach to achieve solvent-resistant and thermally stable organic electronic devices with a remarkably improved air

  18. P300 brain potential among workers exposed to organic solvents

    Directory of Open Access Journals (Sweden)

    Bente E. Moen

    2009-10-01

    Full Text Available  SUMMARYThe P300 component of the auditory event-related brain potential was examined in a group of 11workers exposed to low levels of organic solvents in a paint factory and 11 unexposed controls beforeand after 3 weeks of summer vacation. The P300 latency time was found to be prolonged among theexposed workers compared to the reference group before the summer vacation, and to be significantlylonger before the vacation than after in the exposed group.The P300 component was also examined in a group of 85 seamen from chemical tankers, experiencingpeak exposures to organic solvents. They were compared to a reference group of unexposedseamen. Comparing these two groups, no difference was found in the P300 latency time. No relationshipbetween the P300 latency time and exposure was found in a multiple regression analysis, includingthe variables age, alcohol consumption, smoking and cerebral concussions.The study indicates the occurrence of an acute biological effect in the nervous system related toorganic solvent exposure, expressed by prolonged P300 latency time. This was found at very lowexposure levels and should be studied further.

  19. Falling film evaporators: organic solvent regeneration in nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    Garcin, I.

    1989-01-01

    The aim of this work was to improve knowledge about working of falling film evaporators used in nuclear fuel reprocessing plants for organic solvent regeneration. The first part deals with a non evaporation film. An original film thickness measuring technique was used; infrared thermography. It gave indications on hydrodynamics and wave amplitude and pointed out thermocapillary forces to be the cause of bad wetting of the heated wall. By another way we showed that a small slit spacing on the film distributor, an enhanced surface roughness and an important liquid flow rate favour a better wetting. The second part deals with evaporation of a binary solvent mixture. Experiments in an industrial evaporator corroborated the fact that it is essential for the efficiency of the apparatus to work at high flow rates. We propose an over-simple model which can be used to estimate performances of co-current falling film evaporators of the process [fr

  20. 40 CFR Table 3 to Subpart Nnnn of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Large Appliances Pt. 63, Subpt. NNNN, Table 3 Table 3 to Subpart NNNN of Part 63—Default Organic HAP.../solvent blend CAS. No. Average organic HAP mass fraction Typical organic HAP, percent by mass 1. Toluene...

  1. Effect of Organic Solvents on Microalgae Growth, Metabolism and Industrial Bioproduct Extraction: A Review.

    Science.gov (United States)

    Miazek, Krystian; Kratky, Lukas; Sulc, Radek; Jirout, Tomas; Aguedo, Mario; Richel, Aurore; Goffin, Dorothee

    2017-07-04

    In this review, the effect of organic solvents on microalgae cultures from molecular to industrial scale is presented. Traditional organic solvents and solvents of new generation-ionic liquids (ILs), are considered. Alterations in microalgal cell metabolism and synthesis of target products (pigments, proteins, lipids), as a result of exposure to organic solvents, are summarized. Applications of organic solvents as a carbon source for microalgal growth and production of target molecules are discussed. Possible implementation of various industrial effluents containing organic solvents into microalgal cultivation media, is evaluated. The effect of organic solvents on extraction of target compounds from microalgae is also considered. Techniques for lipid and carotenoid extraction from viable microalgal biomass (milking methods) and dead microalgal biomass (classical methods) are depicted. Moreover, the economic survey of lipid and carotenoid extraction from microalgae biomass, by means of different techniques and solvents, is conducted.

  2. Dissolution of organic solvents from painted surfaces into water

    International Nuclear Information System (INIS)

    Wren, J.C.; Jobe, D.J.; Sanipelli, G.G.; Ball, J.M.

    2000-01-01

    The presence of volatile iodine in containment buildings is one of the major safety concerns in the potential event of nuclear reactor accidents. Organic impurities in containment water, originating from various painted structural surfaces and organic materials, could have a significant impact on iodine volatility following an accident. To determine the source and magnitude of organic impurities and their effects on time-dependent iodine volatility, the dissolution for organic constituents from paints used in reactor buildings has been studied under postulated accident conditions. The studies of the organic dissolution from carbon steel coupons coated with zinc-primed vinyl, epoxy-primed polyurethane or epoxy paints over the temperature range 25-90 deg C are reported. Relatively large activation energies were measured for the release of the principal organic compounds from painted surfaces, suggesting it is the release of the solvents from the paint matrix rather than their diffusion through the solution that is the rate determining step for the dissolution mechanism. The similarities in the values of activation energies for the dissolution of different organic compounds from the paints suggest the release rate is independent of the nature of the painted surface or the type of organic being released from the surface. These two observations indicate that it may be possible to write a generalized rate expression for the release of organic compounds from painted surfaces in containment following an accident. The possible implications of these results for predicting iodine volatility in containment are also discussed. (author)

  3. On linear correlation between interfacial tension of water-solvent interface solubility of water in organic solvents and parameters of diluent effect scale

    International Nuclear Information System (INIS)

    Mezhov, Eh.A.; Khananashvili, N.L.; Shmidt, V.S.

    1988-01-01

    Presence of linear correlation between water solubility in nonmiscible with it organic solvents, interfacial tension of water-solvent interface, on the one hand, and solvent effect scale parameters and these solvents π* - on the other hand, is established. It allows, using certain tabular parameters of solvent effect or each solvent π*, to predict values of interfacial tension and water solubility for corresponding systems. It is shown, that solvent effect scale allows to predict values more accurately, than other known solvent scales, as it in contrast to other scales characterizes solvents, which are in equilibrium with water

  4. Mixed organic solvents induce renal injury in rats.

    Directory of Open Access Journals (Sweden)

    Weisong Qin

    Full Text Available To investigate the injury effects of organic solvents on kidney, an animal model of Sprague-Dawley (SD rats treated with mixed organic solvents via inhalation was generated and characterized. The mixed organic solvents consisted of gasoline, dimethylbenzene and formaldehyde (GDF in the ratio of 2:2:1, and were used at 12,000 PPM to treat the rats twice a day, each for 3 hours. Proteinuria appeared in the rats after exposure for 5-6 weeks. The incidences of proteinuria in male and female rats after exposure for 12 weeks were 43.8% (7/16 and 25% (4/16, respectively. Urinary N-Acetyl-β-(D-Glucosaminidase (NAG activity was increased significantly after exposure for 4 weeks. Histological examination revealed remarkable injuries in the proximal renal tubules, including tubular epithelial cell detachment, cloud swelling and vacuole formation in the proximal tubular cells, as well as proliferation of parietal epithelium and tubular reflux in glomeruli. Ultrastructural examination found that brush border and cytoplasm of tubular epithelial cell were dropped, that tubular epithelial cells were partially disintegrated, and that the mitochondria of tubular epithelial cells were degenerated and lost. In addition to tubular lesions, glomerular damages were also observed, including segmental foot process fusion and loss of foot process covering on glomerular basement membrane (GBM. Immunofluorescence staining indicated that the expression of nephrin and podocin were both decreased after exposure of GDF. In contrast, increased expression of desmin, a marker of podocyte injury, was found in some areas of a glomerulus. TUNEL staining showed that GDF induced apoptosis in tubular cells and glomerular cells. These studies demonstrate that GDF can induce both severe proximal tubular damage and podocyte injury in rats, and the tubular lesions appear earlier than that of glomeruli.

  5. Mixed organic solvents induce renal injury in rats.

    Science.gov (United States)

    Qin, Weisong; Xu, Zhongxiu; Lu, Yizhou; Zeng, Caihong; Zheng, Chunxia; Wang, Shengyu; Liu, Zhihong

    2012-01-01

    To investigate the injury effects of organic solvents on kidney, an animal model of Sprague-Dawley (SD) rats treated with mixed organic solvents via inhalation was generated and characterized. The mixed organic solvents consisted of gasoline, dimethylbenzene and formaldehyde (GDF) in the ratio of 2:2:1, and were used at 12,000 PPM to treat the rats twice a day, each for 3 hours. Proteinuria appeared in the rats after exposure for 5-6 weeks. The incidences of proteinuria in male and female rats after exposure for 12 weeks were 43.8% (7/16) and 25% (4/16), respectively. Urinary N-Acetyl-β-(D)-Glucosaminidase (NAG) activity was increased significantly after exposure for 4 weeks. Histological examination revealed remarkable injuries in the proximal renal tubules, including tubular epithelial cell detachment, cloud swelling and vacuole formation in the proximal tubular cells, as well as proliferation of parietal epithelium and tubular reflux in glomeruli. Ultrastructural examination found that brush border and cytoplasm of tubular epithelial cell were dropped, that tubular epithelial cells were partially disintegrated, and that the mitochondria of tubular epithelial cells were degenerated and lost. In addition to tubular lesions, glomerular damages were also observed, including segmental foot process fusion and loss of foot process covering on glomerular basement membrane (GBM). Immunofluorescence staining indicated that the expression of nephrin and podocin were both decreased after exposure of GDF. In contrast, increased expression of desmin, a marker of podocyte injury, was found in some areas of a glomerulus. TUNEL staining showed that GDF induced apoptosis in tubular cells and glomerular cells. These studies demonstrate that GDF can induce both severe proximal tubular damage and podocyte injury in rats, and the tubular lesions appear earlier than that of glomeruli.

  6. Psychiatric symptomatology in persons with organic solvent exposure.

    Science.gov (United States)

    Morrow, L A; Kamis, H; Hodgson, M J

    1993-02-01

    This study investigated psychiatric symptomatology, self-concept, locus of control, and daily events in persons with a history of exposure to mixtures of organic solvents. Exposed subjects were more likely than controls to report depression, anxiety, fatigue, confusion, and somatic concerns, which in turn were associated with certain exposure-related variables (e.g., cacosmia). There were no differences between the groups in self-concept, locus of control, or ratings of daily hassles and uplifts. Exposed persons may be able to accurately identify what they perceive as changes that are due to the exposure (e.g., anxiety) without attributing these specific adverse outcomes to dispositional variables.

  7. Synthesis of Sub-10 nm Two-Dimensional Covalent Organic Thin Film with Sharp Molecular Sieving Nanofiltration

    KAUST Repository

    Gadwal, Ikhlas; Sheng, Guan; Thankamony, Roshni Lilly; Liu, Yang; Li, Huifang; Lai, Zhiping

    2018-01-01

    We demonstrated here a novel and facile synthesis of two-dimensional (2D) covalent organic thin film with pore size around 1.5 nm using a planar, amphiphilic and substituted heptacyclic truxene based triamine and a simple dialdehyde as building

  8. Synthesis of Sub-10 nm Two-Dimensional Covalent Organic Thin Film with Sharp Molecular Sieving Nanofiltration

    KAUST Repository

    Gadwal, Ikhlas

    2018-04-06

    We demonstrated here a novel and facile synthesis of two-dimensional (2D) covalent organic thin film with pore size around 1.5 nm using a planar, amphiphilic and substituted heptacyclic truxene based triamine and a simple dialdehyde as building blocks by dynamic imine bond formation at the air/water interface using Langmuir–Blodgett (LB) method. Optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM), all unanimously showed the formation of large, molecularly thin and free-standing membrane that can be easily transferred on different substrate surfaces. The 2D membrane supported on a porous polysulfone showed a rejection rate of 64 and 71% for NaCl and MgSO4, respectively, and a clear molecular sieving at molecular size around 1.3 nm, which demonstrated a great potential in the application of pretreatment of seawater desalination and separation of organic molecules.

  9. Characterizing DNA condensation and conformational changes in organic solvents.

    Directory of Open Access Journals (Sweden)

    Fuyou Ke

    Full Text Available Organic solvents offer a new approach to formulate DNA into novel structures suitable for gene delivery. In this study, we examined the in situ behavior of DNA in N, N-dimethylformamide (DMF at low concentration via laser light scattering (LLS, TEM, UV absorbance and Zeta potential analysis. Results revealed that, in DMF, a 21bp oligonucleotide remained intact, while calf thymus DNA and supercoiled plasmid DNA were condensed and denatured. During condensation and denaturation, the size was decreased by a factor of 8-10, with calf thymus DNA forming spherical globules while plasmid DNA exhibited a toroid-like conformation. In the condensed state, DNA molecules were still able to release the counterions to be negatively charged, indicating that the condensation was mainly driven by the excluded volume interactions. The condensation induced by DMF was reversible for plasmid DNA but not for calf thymus DNA. When plasmid DNA was removed from DMF and resuspended in an aqueous solution, the DNA was quickly regained a double stranded configuration. These findings provide further insight into the behavior and condensation mechanism of DNA in an organic solvent and may aid in developing more efficient non-viral gene delivery systems.

  10. Evaluation of the Process of Solvent Vapor Annealing on Organic Thin Films

    KAUST Repository

    Ren, Yi

    2011-01-01

    Solvent vapor annealing has recently emerged as an intriguing, room-temperature, and highly versatile alternative to thermal annealing. The chemically selective interaction between solvents and organic semiconductors opens new opportunities

  11. Recent Advances in Anhydrous Solvents for CO{sub 2} Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

    Energy Technology Data Exchange (ETDEWEB)

    Park, Youngjune [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju (Korea, Republic of); Lin, Kun-Yi Andrew [Department of Environmental Engineering, National Chung Hsing University, Taichung City (China); Park, Ah-Hyung Alissa, E-mail: ap2622@columbia.edu [Department of Earth and Environmental Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Department of Chemical Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Petit, Camille, E-mail: ap2622@columbia.edu [Department of Chemical Engineering, Imperial College London, London (United Kingdom)

    2015-10-01

    CO{sub 2} capture by amine scrubbing, which has a high CO{sub 2} capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO{sub 2} capture from flue gases. The findings from these demonstrations will significantly advance the field of CO{sub 2} capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO{sub 2} capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO{sub 2} capture solvents, which are often anhydrous, have been developed as the third-generation CO{sub 2} capture solvents. These novel classes of liquid materials include ionic liquids, CO{sub 2}-triggered switchable solvents (i.e., CO{sub 2}-binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO{sub 2} capture. Particular attention is given to the mechanisms of CO{sub 2} absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO{sub 2} capture media.

  12. Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

    Directory of Open Access Journals (Sweden)

    YOUNGJUNE ePARK

    2015-10-01

    Full Text Available CO2 capture by amine scrubbing, which has a high CO2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO2 capture solvents including high volatility and corrosiveness of the amine solutions, as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO2 capture solvents, which are often anhydrous, have been developed as the third-generation CO2 capture solvents. These novel classes of liquid materials include: Ionic Liquids (ILs, CO2-triggered switchable solvents (i.e., CO2 Binding Organic Liquids (CO2BOLs, Reversible Ionic Liquids (RevILs, and Nanoparticle Organic Hybrid Materials (NOHMs. This paper provides a review of these various anhydrous solvents and their potential for CO2 capture. Particular attention is given to the mechanisms of CO2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO2 capture media.

  13. Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

    International Nuclear Information System (INIS)

    Park, Youngjune; Lin, Kun-Yi Andrew; Park, Ah-Hyung Alissa; Petit, Camille

    2015-01-01

    CO 2 capture by amine scrubbing, which has a high CO 2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO 2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO 2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO 2 capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO 2 capture solvents, which are often anhydrous, have been developed as the third-generation CO 2 capture solvents. These novel classes of liquid materials include ionic liquids, CO 2 -triggered switchable solvents (i.e., CO 2 -binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO 2 capture. Particular attention is given to the mechanisms of CO 2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO 2 capture media.

  14. Neurobehavioral evaluation of Venezuelan workers exposed to organic solvent mixtures.

    Science.gov (United States)

    Escalona, E; Yanes, L; Feo, O; Maizlish, N

    1995-01-01

    To assess the applicability of the World Health Organization (WHO) Neurobehavioral Core Test Battery (NCTB), we evaluated 53 male and 29 female Venezuelan workers exposed to mixtures of organic solvents in an adhesive factory, and 56 male and 11 female workers unexposed to any type of neurotoxic chemical. The average age of unexposed workers was 30 years and 33 years for those exposed, average schooling for both groups was 8 years, and the mean duration of exposure was 7 years. The NCTB, which assesses central nervous system functions, is composed of seven tests that measure simple motor function, short-term memory, eye-hand coordination, affective behavior, and psychomotor perception and speed. The battery includes: profile of mood states (POMS); Simple Reaction Time for attention and response speed; Digit Span for auditory memory; Santa Ana manual dexterity; Digit-Symbol for perceptual motor speed; the Benton visual retention for visual perception and memory; and Pursuit Aiming II for motor steadiness. In each of 13 subtests, the exposed group had a poorer performance than the nonexposed group. The range of differences in mean performance was between 5% and 89%, particularly in POMS (tension-anxiety, anger-hostility, depression-rejection, fatigue-inertia, confusion-bewilderment), Simple Reaction Time, Digit-Symbol, and Santa Ana Pegboard (p memory, confusion, paresthesias in upper and lower extremities, and sleep disturbances. We conclude that the methodology is applicable to the population studied. The tests of the NCTB were accepted by the subjects and were administered satisfactorily, except for occasional difficulties in verbal comprehension in subtests of POMS, which is the only test that requires more demanding verbal skills. The magnitude of the behavioral deficits is consistent with the probable high level of exposure and with the range of deficits previously reported in workers with long-term solvent exposures.

  15. Ultrafiltration and Nanofiltration Multilayer Membranes Based on Cellulose

    KAUST Repository

    Livazovic, Sara

    2016-06-09

    Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose, has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. In the search for less harsh, greener membrane manufacture, the combination of cellulose and ionic liquid is of high interest. Due to the abundance of OH groups and hydrophilicity, cellulose-based membranes have high permeability and low fouling tendency. Membrane fouling is one of the biggest challenges in membrane industry and technology. Accumulation and deposition of foulants onto the surface reduce membrane efficiency and requires harsh chemical cleaning, therefore increasing the cost of maintenance and replacement. In this work the resistance of cellulose 5 membranes towards model organic foulants such as Suwanee River Humic Acid (SRHA) and crude oil have been investigated. Cellulose membrane was tested in this work for oil-water (o/w) separation and exhibited practically 100 % oil rejection with good flux recovery ratio and membrane resistivity. The influence of anionic, cationic and ionic surfactant as well as pH and crude oil concentration on oil separation was investigated, giving a valuable insight in experimental and operational planning.

  16. 40 CFR Table 6 to Subpart Vvvv of... - Default Organic HAP Contents of Petroleum Solvent Groups

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Contents of... Manufacturing Pt. 63, Subpt. VVVV, Table 6 Table 6 to Subpart VVVV of Part 63—Default Organic HAP Contents of Petroleum Solvent Groups As specified in § 63.5758(a)(6), when detailed organic HAP content data for solvent...

  17. Organic solvent exposure and contrast sensitivity: comparing men and women

    Science.gov (United States)

    Oliveira, A.R.; Campos, A.A.; de Andrade, M.J.O.; de Medeiros, P.C.B.; dos Santos, N.A.

    2018-01-01

    The goal of this study was to compare the visual contrast sensitivity (CS) of men and women exposed and not exposed to organic solvents. Forty-six volunteers of both genders aged between 18 and 41 years (mean±SD=27.72±6.28) participated. Gas station attendants were exposed to gas containing 46.30 ppm of solvents at a temperature of 304±274.39 K, humidity of 62.25±7.59% and ventilation of 0.69±0.46 m/s (a passive gas chromatography-based sampling method was used considering the microclimate variables). Visual CS was measured via the psychophysical method of two-alternative forced choice using vertical sinusoidal gratings with spatial frequencies of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0, and 16.0 cpd (cycles per degree) and an average luminance of 34.4 cd/m2. The results showed that visual CS was significantly lower (P<0.05) in the following groups: i) exposed men compared to unexposed men at frequencies of 0.2, 0.5, 1.0, and 2.0 cpd; ii) exposed women compared to unexposed women at a frequency of 5.0 cpd; and iii) exposed women compared to exposed men at a frequency of 0.5 cpd, even at exposures below the tolerance limit (300 ppm). These results suggest that the visual CS of exposed men was impaired over a wider range of spatial frequencies than that of exposed women. This difference may have been due to the higher body fat content of women compared to that of men, suggesting that body fat in women can serve as a protective factor against neurotoxic effects. PMID:29340521

  18. Characterisation of aggregation of tributylphosphate molecules in organic solvent

    International Nuclear Information System (INIS)

    Mandin, C.; Martinet, L.; Zemb, Th.; Berthon, L.; Madic, Ch.

    2000-01-01

    This report presents a structural study of the aggregates formed with the organic phases of the extractant tri-n-butyl phosphate, used in the industrial PUREX process (Plutonium and Uranium Extraction; liquid-liquid solvent extraction) for the treatment of high radioactive waste. Combined Small Angle X-ray Scattering and Small Angle Neutron Scattering show that organic TBP solutions (in equilibrium with acid solutions) are organised in oligomeric aggregates. The influence of various parameters such as HNO 3 or TBP concentrations, diluent or acid natures, does not seem to modify the aggregate shape and size, whereas the interactions are modified. Moreover the aggregates disappear under high temperatures, whereas the attractive interactions between them increase at low temperatures. The 'drop weight' method gives the critical micellar concentration values of TBP in case of H 2 O or HNO 3 extractions (H 2 O: 0.48 M; HNO 3 2M: 0.65 M; at 21 deg C). Furthermore, the measures at different acid concentrations show that the c.m.c. varies with the acidity. The more acid the aqueous phase is, the smaller is the entropy in the system because of the numerous negative charges, i.e. the harder the micellization occurs, so the higher the c.m.c. value is. The sticky sphere model proposed by Baxter, can be used to model successfully small reverse micelles of the organic TBP phases. The aggregation number would be 4±1 (water extraction) and 5±1(HNO 3 2M extraction). These values are also given by vapor pressure measurements. (authors)

  19. On the solubility of nicotinic acid and isonicotinic acid in water and organic solvents

    International Nuclear Information System (INIS)

    Abraham, Michael H.; Acree, William E.

    2013-01-01

    Highlights: ► Solubilities of nicotinic acid and isonicotinic acids in organicsolvents have been determined. ► Solubilities are used to calculate Abraham descriptors for the two acids. ► These descriptors then yield water-solvent and gas-solvent partitions into numerous solvents. ► The solubility of the neutral acids in water is obtained. ► The method is straightforward and can be applied to any set of compound solubilities. -- Abstract: We have determined the solubility of nicotinic acid in four solvents and the solubility of isonicotinic acid in another four solvents. These results, together with literature data on the solubility of nicotinic acid in five other organic solvents and isonicotinic acid in four other organic solvents, have been analyzed through two linear Gibbs energy relationships in order to extract compound properties, or descriptors, that encode various solute–solvent interactions. The descriptors for nicotinic acid and isonicotinic acid can then be used in known equations for partition of solutes between water and organic solvents to predict partition coefficients and then further solubility in a host of organic solvents, as well as to predict a number of other physicochemical properties

  20. Silica Gel-Mediated Organic Reactions under Organic Solvent-Free Conditions

    Directory of Open Access Journals (Sweden)

    Satoaki Onitsuka

    2012-09-01

    Full Text Available Silica gel was found to be an excellent medium for some useful organic transformations under organic solvent-free conditions, such as (1 the Friedel-Crafts-type nitration of arenes using commercial aqueous 69% nitric acid alone at room temperature, (2 one-pot Wittig-type olefination of aldehydes with activated organic halides in the presence of tributyl- or triphenylphosphine and Hunig’s base, and (3 the Morita-Baylis-Hillman reaction of aldehydes with methyl acrylate. After the reactions, the desired products were easily obtained in good to excellent yields through simple manipulation.

  1. Solvents, Ethanol, Car Crashes and Tolerance: How Risky is Inhalation of Organic Solvents?

    Science.gov (United States)

    A research program in the National Health and Environmental Effects Research Laboratory of the U.S. EPA has led to some surprising considerations regarding the potential hazard of exposure to low concentrations of solvent vapors. This program involved conducting experiments to ch...

  2. Study on electrohydrodynamic jetting performance of organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo Hong; Nguyen, Xuan Hung; Gim, Yeong Hyeon; Ko, Han Seo [Sungkyunkwan University, Suwon (Korea, Republic of)

    2015-11-15

    The electrohydrodynamic (EHD) inkjet method is a printing technology using electricity. This technique allows for the printing of EML (Emission layer) materials, usually used for OLED devices, on a substrate. In this study, ejection experiments were performed with various solvents to verify which of them is properly ejected in the EHD method. The solvents employed were dielectric liquids with low viscosity and it was confirmed that among them two solvents, 1,2-Dichlorobenzene (DCB) and 1,2-Dichloroethane (DCE), produced the pulsating cone-Jet mode and stable cone-jet mode well. In addition, experiments were conducted to find out how the voltage and applied flux influence the ejection mode, in order to apply the result to the ejection control. It was found that the selected solvent was easily ejected and printed, due to the free surface charge and charge density determined by the dielectric constant. Finally, a patterning experiment was performed to verify proper printing.

  3. On-line removal of volatile fatty acids from CELSS anaerobic bioreactor via nanofiltration.

    Science.gov (United States)

    Colon, G; Sager, J C

    2001-01-01

    The CELSS resource recovery system, which is a waste-processing system, uses aerobic and anaerobic bioreactors to recover plants nutrients and secondary foods from the inedible biomass. The anaerobic degradation of the inedible biomass, by means of culture of rumen bacteria, generates organic compounds such as volatile fatty acids (VFA) (acetic, propionic, butyric) and ammonia. The presence of VFA in the bioreactor medium at fairly low concentrations decreases the microbial population's metabolic reactions due to end-product inhibition. Technologies to remove VFA continuously from the bioreactor are of high interest. Several candidate technologies were analyzed, such as organic solvent liquid-liquid extraction, adsorption and/or ion exchange, dialysis, electrodialysis, and pressure-driven membrane separation processes. The proposed technique for the on-line removal of VFA from the anaerobic bioreactor was a nanofiltration membrane recycle bioreactor. In order to establish the nanofiltration process performance variables before coupling it to the bioreactor, a series of experiments was carried out using a 10,000 molecular weight cutoff (MWCO) tubular ceramic membrane module. The variables studied were the bioreactor slurry permeation characteristics, such as: the permeate flux, VFA and nutrient removal rates as a function of applied transmembrane pressure, fluid recirculation velocity, suspended matter concentration, and process operating time. Results indicated that the permeate flux, VFA, and nutrients removal rates are directly proportional to the fluid recirculation velocity in the range between 0.6 and 1.0 m/s, applied pressure when these are lower than 1.5 bar, and inversely proportional to the total suspended solids concentration in the range between 23,466 and 34,880 mg/L. At applied pressure higher than 1.5 bar the flux is not more linearly dependent due to concentration polarization and fouling effects over the membrane surface. It was also found that the

  4. On-line removal of volatile fatty acids from CELSS anaerobic bioreactor via nanofiltration

    Science.gov (United States)

    Colon, Guillermo

    1995-01-01

    The CELSS (controlled ecological life support system) resource recovery system, which is a waste processing system, uses aerobic and anaerobic bioreactors to recover plants nutrients and secondary foods from the inedible biomass. The anaerobic degradation of the inedible biomass by means of culture of rumen bacteria,generates organic compounds such as volatile fatty acids (acetic, propionic, butyric, VFA) and ammonia. The presence of VFA in the bioreactor medium at fairly low concentrations decreases the microbial population's metabolic reactions due to end-product inhibition. Technologies to remove VFA continuously from the bioreactor are of high interest. Several candidate technologies were analyzed, such as organic solvent liquid-liquid extraction, adsorption and/or ion exchange, dialysis, electrodialysis, and pressure driven membrane separation processes. The proposed technique for the on-line removal of VFA from the anaerobic bioreactor was a nanofiltration membrane recycle bioreactor. In order to establish the nanofiltration process performance variables before coupling it to the bioreactor, a series of experiments were carried out using a 10,000 MWCO tubular ceramic membrane module. The variables studied were the bioreactor slurry permeation characteristics, such as, the permeate flux, VFA and the nutrient removal rates as a function of applied transmembrane pressure, fluid recirculation velocity, suspended matter concentration, and process operating time. Results indicate that the permeate flux, VFA and nutrients removal rates are directly proportional to the fluid recirculation velocity in the range between 0.6 to 1.0 m/s, applied pressure when these are low than 1.5 bar, and inversely proportional to the total suspended solids concentration in the range between 23,466 to 34,880. At applied pressure higher than 1.5 bar the flux is not more linearly dependent due to concentration polarization and fouling effects over the membrange surface. It was also found

  5. Measurement of dielectric constant of organic solvents by indigenously developed dielectric probe

    Science.gov (United States)

    Keshari, Ajay Kumar; Rao, J. Prabhakar; Rao, C. V. S. Brahmmananda; Ramakrishnan, R.; Ramanarayanan, R. R.

    2018-04-01

    The extraction, separation and purification of actinides (uranium and plutonium) from various matrices are an important step in nuclear fuel cycle. One of the separation process adopted in an industrial scale is the liquid-liquid extraction or solvent extraction. Liquid-liquid extraction uses a specific ligand/extractant in conjunction with suitable diluent. Solvent extraction or liquid-liquid extraction, involves the partitioning of the solute between two immiscible phases. In most cases, one of the phases is aqueous, and the other one is an organic solvent. The solvent used in solvent extraction should be selective for the metal of interest, it should have optimum distribution ratio, and the loaded metal from the organic phase should be easily stripped under suitable experimental conditions. Some of the important physical properties which are important for the solvent are density, viscosity, phase separation time, interfacial surface tension and the polarity of the extractant.

  6. Validation of a UV Spectrometric Method for the Assay of Tolfenamic Acid in Organic Solvents

    Directory of Open Access Journals (Sweden)

    Sofia Ahmed

    2015-01-01

    Full Text Available The present study has been carried out to validate a UV spectrometric method for the assay of tolfenamic acid (TA in organic solvents. TA is insoluble in water; therefore, a total of thirteen commonly used organic solvents have been selected in which the drug is soluble. Fresh stock solutions of TA in each solvent in a concentration of 1 × 10−4 M (2.62 mg% were prepared for the assay. The method has been validated according to the guideline of International Conference on Harmonization and parameters like linearity, range, accuracy, precision, sensitivity, and robustness have been studied. Although the method was found to be efficient for the determination of TA in all solvents on the basis of statistical data 1-octanol, followed by ethanol and methanol, was found to be comparatively better than the other studied solvents. No change in the stock solution stability of TA has been observed in each solvent for 24 hours stored either at room (25±1°C or at refrigerated temperature (2–8°C. A shift in the absorption maxima has been observed for TA in various solvents indicating drug-solvent interactions. The studied method is simple, rapid, economical, accurate, and precise for the assay of TA in different organic solvents.

  7. Cooling crystallization of Indomethacin from different organic solvents

    DEFF Research Database (Denmark)

    Malwade, Chandrakant Ramkrishna; Qu, Haiyan

    , 25, 35, and 45 °C. The solvents with varying polarities (ethanol, methanol, ethyl acetate, acetone, acetonitrile, and dichloromethane) were used for solubility measurement. Maximum solubility of IMC was observed in acetone, while acetonitrile showed the lowest solubility. Solid phase analysis...... of excess solute with XRPD and Raman spectroscopy confirmed formation of IMC solvate in acetone, methanol and dichloromethane at 15 °C. Based on solubility of IMC, the solvents ethanol, ethyl acetate, acetone, and dichloromethane were selected for crystallization experiments. Nucleation kinetics of IMC...... in selected solvents was investigated through the measurement of induction time at 5 °C and 15 °C. Longer induction times were observed for IMC in ethanol at both temperatures compared to the one in acetone. Metastable α form of IMC was obtained from ethanol, while solvate of IMC was produced from acetone....

  8. Assessment of Relationship between Spontaneous Abortion and Occupational Exposure to Organic Solvents

    Directory of Open Access Journals (Sweden)

    S Mohammadi

    2011-04-01

    Full Text Available Introduction & Objective: Nowadays, some studies indicate the adverse effects of exposure to chemicals, especially organic solvents on the reproductive system of females. This study aimed to assess the relationship between spontaneous abortion with occupational exposure to organic solvents in pharmaceutical industry. Materials & Methods: This is a cross-sectional and descriptive-analytical study which was carried out in 2010 in one of the pharmaceutical factories located in the suburbs of Tehran. During the study, married women who were working in the factory laboratory units and were exposed to mixed organic solvents were compared with married women who were working in the packing units of the factory without occupational exposure to organic solvents. Frequency of spontaneous abortion and duration of pregnancy were assessed in both two groups. Collected data were analyzed with the SPSS software using t-test, logistic regression, and chi-square test. Results: In the present study, the frequency of spontaneous abortion in employees with exposure to organic solvents mixture was 10.7%. This study showed that even after adjustment for confounding factors, there was a significant correlation between spontaneous abortion and occupational exposure to organic solvents mixture and this correlation increased with increasing levels of exposure to organic solvents. Moreover, a significant correlation was observed between occupational exposure to mixed organic solvents and waiting time to become pregnant (TTP. Furthermore, this study showed that even after adjustment for confounding variables, shift workers were significantly more affected by spontaneous abortion compared to daytime workers (P < 0.001. Conclusion: According to the results of this study, since there is probability of spontaneous abortion resulting from occupational exposure to various chemicals including organic solvents, review of the status of occupational exposure of workers can be helpful

  9. Organic solvent pretreatment of lignocellulosic biomass for biofuels and biochemicals: A review.

    Science.gov (United States)

    Zhang, Ke; Pei, Zhijian; Wang, Donghai

    2016-01-01

    Lignocellulosic biomass represents the largest potential volume and lowest cost for biofuel and biochemical production. Pretreatment is an essential component of biomass conversion process, affecting a majority of downstream processes, including enzymatic hydrolysis, fermentation, and final product separation. Organic solvent pretreatment is recognized as an emerging way ahead because of its inherent advantages, such as the ability to fractionate lignocellulosic biomass into cellulose, lignin, and hemicellulose components with high purity, as well as easy solvent recovery and solvent reuse. Objectives of this review were to update and extend previous works on pretreatment of lignocellulosic biomass for biofuels and biochemicals using organic solvents, especially on ethanol, methanol, ethylene glycol, glycerol, acetic acid, and formic acid. Perspectives and recommendations were given to fully describe implementation of proper organic solvent pretreatment for future research. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Exploring orange peel treatment with deep eutectic solvents and diluted organic acids

    NARCIS (Netherlands)

    van den Bruinhorst, A.; Kouris, P.; Timmer, J.M.K.; de Croon, M.H.J.M.; Kroon, M.C.

    2016-01-01

    The disintegration of orange peel waste in deep eutectic solvents and diluted organic acids is presented in this work. The albedo and flavedo layers of the peel were studied separately, showing faster disintegration of the latter. Addition of water to the deep eutectic solvents lowered the amount of

  11. Photostability of solutions of rare earth chelates in organic solvents and polymers

    International Nuclear Information System (INIS)

    Karasev, V.E.; Mirochnik, A.G.; Lysun, T.V.; Vovna, V.I.

    1990-01-01

    Consideration is given to results of comparative study of photochemical properties of rare erath chelate complexes (adducts of rare earth β-diketonates with triphenylphosphine oxide, hexamethylphosphotriamide, phenanthroline) in organic solvents and polymers. Effect of excitation conditions, composition, solvent, nature of ligand and rare earth ion on photolysis rate was investigated. 9 refs.; 2 figs.; 4 tabs

  12. A comparison of the activities of three beta-galactosidases in aqueous-organic solvent mixtures

    NARCIS (Netherlands)

    Yoon, JH; Mckenzie, D

    2005-01-01

    The hydrolytic activities of beta-galactosidases from three different sources have been determined in various 50% (v/v) organic solvent-buffer mixtures with a view to finding solvent systems of reduced water content suitable for the synthesis of glycosides and oligosaccharides. K. fragilis

  13. Synthesis of silver nanocubes in a hydrophobic binary organic solvent.

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S.; Sun, Y. (Center for Nanoscale Materials)

    2010-01-01

    Synthesis of metal nanoparticles with controlled shapes in hydrophobic solvents is challenging because homogeneous nucleation with high rate in these solvents is favorable for the formation of multiply twinned (MT) nanoparticles with spherical morphology. In this work, we report an inhomogeneous nucleation strategy in a binary hydrophobic solvent mediated by dimethyldistearylammonium chloride (DDAC), resulting in the coexistence of single-crystalline Ag polyhedrons and MT Ag quasi-spheres at the beginning of the reaction. In the consequent step, the MT Ag nanoparticles are selectively etched and dissolved through oxidation by NO{sub 3}{sup -} ions (from the Ag precursor, AgNO{sub 3}) with the assistance of Cl{sup -} ions (from DDAC). The dissolved Ag species are then reduced and deposited on the more stable single-crystalline polyhedrons to form Ag nanocubes. Synergy of the oxidative etching of MT particles and growth of single-crystalline particles leads to Ag nanocubes with high purity when the ripening time is long enough. For example, refluxing a mixing solvent of octyl ether and oleylamine containing AgNO{sub 3} (0.02 M) and DDAC (0.03 M) at 260 C for 1 h results in Ag nanocubes with an average edge length of 34 nm and a purity higher than 95%.

  14. Photonic crystal based sensor for organic solvents and for solvent-water mixtures.

    Science.gov (United States)

    Fenzl, Christoph; Hirsch, Thomas; Wolfbeis, Otto S

    2012-12-12

    Monodisperse polystyrene nanoparticles with a diameter of 173 nm were incorporated into a polydimethylsiloxane matrix where they display an iridescent color that can be attributed to the photonic crystal effect. The film is of violet color if placed in plain water, but turns to red in the presence of the non-polar solvent n-hexane. Several solvents were studied in some detail. We show that such films are capable of monitoring the water content of ethanol/water mixtures, where only 1% (v/v) of water leads to a shift of the peak wavelength of reflected light by 5 nm. The method also can be applied to determine, both visually and instrumentally, the fraction of methanol in ethanol/methanol mixtures. Here, a fraction of 1% of methanol (v/v) results in a wavelength shift of 2 nm. The reflected wavelength is not influenced by temperature changes nor impeded by photobleaching. The signal changes are fully reversible and response times are <1 s.

  15. Photonic Crystal Based Sensor for Organic Solvents and for Solvent-Water Mixtures

    Directory of Open Access Journals (Sweden)

    Otto S. Wolfbeis

    2012-12-01

    Full Text Available Monodisperse polystyrene nanoparticles with a diameter of 173 nm were incorporated into a polydimethylsiloxane matrix where they display an iridescent color that can be attributed to the photonic crystal effect. The film is of violet color if placed in plain water, but turns to red in the presence of the non-polar solvent n-hexane. Several solvents were studied in some detail. We show that such films are capable of monitoring the water content of ethanol/water mixtures, where only 1% (v/v of water leads to a shift of the peak wavelength of reflected light by 5 nm. The method also can be applied to determine, both visually and instrumentally, the fraction of methanol in ethanol/methanol mixtures. Here, a fraction of 1% of methanol (v/v results in a wavelength shift of 2 nm. The reflected wavelength is not influenced by temperature changes nor impeded by photobleaching. The signal changes are fully reversible and response times are <1 s.

  16. Screening for organic solvents in Hanford waste tanks using organic vapor concentrations

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Sklarew, D.S.

    1997-09-01

    The potential ignition of organic liquids stored in the Hanford Site high-level radioactive waste tanks has been identified as a safety issue because expanding gases could potentially affect tank dome integrity. Organic liquid waste has been found in some of the waste tanks, but most are thought to contain only trace amounts. Due to the inhomogeneity of the waste, direct sampling of the tank waste to locate organic liquids may not conclusively demonstrate that a given tank is free of risk. However, organic vapors present above the organic liquid waste can be detected with a high degree of confidence and can be used to identify problem tanks. This report presents the results of a screening test that has been applied to 82 passively ventilated high-level radioactive waste tanks at the Hanford Site to identify those that might contain a significant amount of organic liquid waste. It includes seven tanks not addressed in the previous version of this report, Screening for Organic Solvents in Hanford Waste Tanks Using Total Non-Methane Organic Compound Vapor Concentrations. The screening test is based on a simple model of the tank headspace that estimates the effective surface area of semivolatile organic liquid waste in a tank. Analyses indicate that damage to the tank dome is credible only if the organic liquid burn rate is above a threshold value, and this can occur only if the surface area of organic liquid in a tank is above a corresponding threshold value of about one square meter. Thirteen tanks were identified as potentially containing at least that amount of semivolatile organic liquid based on conservative estimates. Most of the tanks identified as containing potentially significant quantities of organic liquid waste are in the 241-BY and 241-C tank farms, which agrees qualitatively with the fact that these tank farms received the majority of the PUREX process organic wash waste and waste organic liquids

  17. Application and results of whole-body autoradiography in distribution studies of organic solvents.

    Science.gov (United States)

    Bergman, K

    1983-01-01

    With the growing concern for the health hazards of occupational exposure to toxic substances attention has been focused on the organic solvents, which are associated with both deleterious nervous system effects and specific tissue injuries. Relatively little is known about the distribution of organic solvents and their metabolites in the living organism. Knowledge of the specific tissue localizations and retention of solvents and solvent metabolites is of great value in revealing and understanding the sites and mechanisms of organic solvent toxicity. Whole-body autoradiography has been modified and applied to distribution studies of benzene, toluene, m-xylene, styrene, methylene chloride, chloroform, carbon tetrachloride, trichloroethylene and carbon disulfide. The high volatility of these substances has led to the development of cryo-techniques. Whole-body autoradiographic techniques applicable to the study of volatile substances are reviewed. The localizations of nonvolatile solvent metabolites and firmly bound metabolites have also been examined. The obtained results are discussed in relation to toxic effects and evaluated by comparison with other techniques used in distribution studies of organic solvents and their metabolites.

  18. Organic solvent exposure and depressive symptoms among licensed pesticide applicators in the Agricultural Health Study.

    Science.gov (United States)

    Siegel, Miriam; Starks, Sarah E; Sanderson, Wayne T; Kamel, Freya; Hoppin, Jane A; Gerr, Fred

    2017-11-01

    Although organic solvents are often used in agricultural operations, neurotoxic effects of solvent exposure have not been extensively studied among farmers. The current analysis examined associations between questionnaire-based metrics of organic solvent exposure and depressive symptoms among farmers. Results from 692 male Agricultural Health Study participants were analyzed. Solvent type and exposure duration were assessed by questionnaire. An "ever-use" variable and years of use categories were constructed for exposure to gasoline, paint/lacquer thinner, petroleum distillates, and any solvent. Depressive symptoms were ascertained with the Center for Epidemiologic Studies Depression Scale (CES-D); scores were analyzed separately as continuous (0-60) and dichotomous (distillates, and short duration of petroleum distillate exposure and continuous CES-D score (p < 0.05). Although nearly all associations were positive, fewer statistically significant associations were observed between metrics of solvent exposure and the dichotomized CES-D variable. Solvent exposures were associated with depressive symptoms among farmers. Efforts to limit exposure to organic solvents may reduce the risk of depressive symptoms among farmers.

  19. Wastewater treatment by nanofiltration membranes

    Science.gov (United States)

    Mulyanti, R.; Susanto, H.

    2018-03-01

    Lower energy consumption compared to reverse osmosis (RO) and higher rejection compared to ultrafiltration make nanofiltration (NF) membrane get more and more attention for wastewater treatment. NF has become a promising technology not only for treating wastewater but also for reusing water from wastewater. This paper presents various application of NF for wastewater treatments. The factors affecting the performance of NF membranes including operating conditions, feed characteristics and membrane characteristics were discussed. In addition, fouling as a severe problem during NF application is also presented. Further, future prospects and challenges of NF for wastewater treatments are explained.

  20. A NOVEL HYDROPHILIC POLYMER MEMBRANE FOR THE DEHYDRATION OF ORGANIC SOLVENTS

    Science.gov (United States)

    Novel hydrophilic polymer membranes based on polyallylamine ydrochloride- polyvinylalcohol are developed. The high selectivity and flux characteristics of these membranes for the dehydration of organic solvents are evaluated using pervaporation technology and are found to be ver...

  1. Nanoencapsulation of OPAA With Mesoporous Materials for Chemical Agent Decontamination in Organic Solvents

    National Research Council Canada - National Science Library

    Ong, K. K; Dong, H; Wei, Y; Cheng, T-c; Yin, R

    2003-01-01

    .... The enzyme activity in different matrices was evaluated in various organic solvents. Significant activities were retained in most of these matrices, particularly in the presence of acetone and dimethyl formamide...

  2. Bulk heterojunction organic photovoltaic cell fabricated by the electrospray deposition method using mixed organic solvent

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Takeshi; Takagi, Kenji; Asano, Takashi [Department of Functional Materials Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); RIKEN, 2-1 Hirosawa, Wakou-shi, Saitama 351-0198 (Japan); Honda, Zentaro; Kamata, Norihiko; Ueno, Keiji; Shirai, Hajime [Department of Functional Materials Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Ju, Jungmyoung; Yamagata, Yutaka; Tajima, Yusuke [RIKEN, 2-1 Hirosawa, Wakou-shi, Saitama 351-0198 (Japan)

    2011-07-15

    A high-efficiency bulk heterojunction organic photovoltaic cell (OPV) was achieved by the electrospray deposition method. The surface roughness of the P3HT:PCBM thin film can be reduced using the mixed solvent consisting of o-dichlorobenzene (o-DCB) and acetone. The effect of acetone concentration is related to its dielectric constant. Under an optimized concentration of acetone in o-DCB (20 vol%), the P3HT/PCBM active layer with a smooth surface can be formed, and the power conversion efficiency of the OPV was 1.9%. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. DNA damage and cytotoxicity in pathology laboratory technicians exposed to organic solvents

    Directory of Open Access Journals (Sweden)

    TATIANE DE AQUINO

    2016-03-01

    Full Text Available The aim of this study was to evaluate potential DNA damage and cytotoxicity in pathology laboratory technicians exposed to organic solvents, mainly xylene. Peripheral blood and buccal cells samples were collected from 18 technicians occupationally exposed to organic solvents and 11 non-exposed individuals. The technicians were sampled at two moments: Monday and Friday. DNA damage and cytotoxicity were evaluated using the Comet Assay and the Buccal Micronucleus Cytome assay. Fifteen subjects (83.5% of the exposed group to solvents complained about some symptom probably related to contact with vapours of organic solvents. DNA damage in the exposed group to solvents was nearly 2-fold higher on Friday than on Monday, and in both moments the individuals of this group showed higher levels of DNA damage in relation to controls. No statistical difference was detected in buccal cell micronucleus frequency between the laboratory technicians and the control group. However, in the analysis performed on Friday, technicians presented higher frequency (about 3-fold of karyolytic and apoptotic-like cells (karyorrhectic and pyknotic in relation to control group. Considering the damage frequency and the working time, a positive correlation was found in the exposed group to solvents (r=0.468; p=0.05. The results suggest that pathology laboratory workers inappropriately exposed to organic solvents have increased levels of DNA damage.

  4. Understanding Solvent Manipulation of Morphology in Bulk-Heterojunction Organic Solar Cells.

    Science.gov (United States)

    Chen, Yuxia; Zhan, Chuanlang; Yao, Jiannian

    2016-10-06

    Film morphology greatly influences the performance of bulk-heterojunction (BHJ)-structure-based solar cells. It is known that an interpenetrating bicontinuous network with nanoscale-separated donor and acceptor phases for charge transfer, an ordered molecular packing for exciton diffusion and charge transport, and a vertical compositionally graded structure for charge collection are prerequisites for achieving highly efficient BHJ organic solar cells (OSCs). Therefore, control of the morphology to obtain an ideal structure is a key problem. For this solution-processing BHJ system, the solvent participates fully in film processing. Its involvement is critical in modifying the nanostructure of BHJ films. In this review, we discuss the effects of solvent-related methods on the morphology of BHJ films, including selection of the casting solvent, solvent mixture, solvent vapor annealing, and solvent soaking. On the basis of a discussion on interaction strength and time between solvent and active materials, we believe that the solvent-morphology-performance relationship will be clearer and that solvent selection as a means to manipulate the morphology of BHJ films will be more rational. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Cerebrospinal fluid cells and proteins in patients occupationally exposed to organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Juntunen, J; Taskinen, E; Luisto, M; Iivanainen, M; Nurminen, M

    1982-06-01

    Cerebrospinal fluid (CSF) cells and proteins were determined for 33 patients exposed to industrial organic solvents. A lymphoid reaction, i.e., a pathologically elevated number or percentage of enlarged lymphoid cells was observed in one-third of the patients, more often in patients with chronic intoxication (40%) than in those currently exposed to organic solvents (32%). An almost significant decrease of small lymphocytes in the CSF was observed among patients who had a past history of chronic solvent intoxication but no recent exposure. No cytological evidence of tissue destruction was found. Signs of slight blood--CSF barrier damage occurred in 5 (23%) of the currently exposed patients, but intrathecal IgG synthesis was not observed. Increased cellular activity in the CSF was also accentuated in principal component analysis. The results suggest slight nonspecific immunoactivation in the central nervous system of subjects exposed to organic solvents.

  6. The effects of crown ethers on the activity of enzymes in organic solvents

    NARCIS (Netherlands)

    van Unen, D.J.; Engbersen, Johannes F.J.; Reinhoudt, David; Vulfson, Evgeny N.; Halling, Peter J.; Holland, Herbert L.

    2001-01-01

    Currently, the applicability of enzymes in synthetic organic chemistry is well recognized. The field of enzyme-catalyzed organic synthesis has been further boosted by the recognition that enzymes can operate in organic solvents. The use of nonaqueous media for enzymatic conversions offers a number

  7. Revisiting the effects of organic solvents on the thermal reduction of graphite oxide

    International Nuclear Information System (INIS)

    Barroso-Bujans, Fabienne; Fierro, José Luis G.; Alegría, Angel; Colmenero, Juan

    2011-01-01

    Highlights: ► Retention of organic solvent on graphite oxide interlayer space. ► Decreasing exfoliation temperature. ► Close link between structure and thermal behavior of solvent treated graphite oxide. ► Restacking inhibition of thermally reduced graphite oxide sheets. ► Changes in kinetic mechanisms of thermal reduction. - Abstract: Treatment of graphite oxide (GO) with organic solvents via sorption from either liquid or gas phase, and subsequent desorption, induces profound changes in the layered GO structure: loss of stacking order, retention of trace amounts of solvents and decreasing decomposition temperature. This study presents new evidences of the effect of organic solvents on the thermal reduction of GO by means of thermogravimetric analysis, X-ray diffraction and X-ray photoelectron spectroscopy. The results reveal a relative higher decrease of the oxygen amounts in solvent-treated GO as compared to untreated GO and the restacking inhibition of the thermally reduced GO sheets upon slow heating. The kinetic experiments evidence changes occurring in the reduction mechanisms of the solvent-treated GO, which support the close link between GO structure and thermal properties.

  8. Exposure Characteristics of Construction Painters to Organic Solvents

    Directory of Open Access Journals (Sweden)

    Hyunhee Park

    2016-03-01

    Conclusion: From this study, we recognized that construction painters are exposed to various solvents, including carcinogens and reproductive toxins, and the levels of TVOC concentration in many of the painting tasks exceeded the exposure limits. Construction workers need to be protected from chemical agents during their painting works by using personal protective devices and/or work practice measures. Additional studies should focus on the exposure assessment of other hazards for construction workers, in order to identify high-risk tasks and to improve hazardous work environments.

  9. An organic solvent-, detergent-, and thermo-stable alkaline protease from the mesophilic, organic solvent-tolerant Bacillus licheniformis 3C5.

    Science.gov (United States)

    Rachadech, W; Navacharoen, A; Ruangsit, W; Pongtharangkul, T; Vangnai, A S

    2010-01-01

    Bacillus licheniformis 3C5, isolated as mesophilic bacterium, exhibited tolerance towards a wide range of non-polar and polar organic solvents at 45 degrees C. It produced an extracellular organic solvent-stable protease with an apparent molecular mass of approximately 32 kDa. The inhibitory effect of PMSF and EDTA suggested it is likely to be an alkaline serine protease. The protease was active over abroad range of temperatures (45-70 degrees C) and pH (8-10) range with an optimum activity at pH 10 and 65 degrees C. It was comparatively stable in the presence ofa relatively high concentration (35% (v/v)) of organic solvents and various types of detergents even at a relatively high temperature (45 degrees C). The protease production by B. licheniformis 3C5 was growth-dependent. The optimization of carbon and nitrogen sources for cell growth and protease production revealed that yeast extract was an important medium component to support both cell growth and the protease production. The overall properties of the protease produced by B. licheniformis 3C5 suggested that this thermo-stable, solvent-stable, detergent-stable alkaline protease is a promising potential biocatalyst for industrial and environmental applications.

  10. Interaction of organic solvent with a subbituminous coal below pyrolysis temperature

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, D.; Grens, E.A.

    1978-06-01

    The interactions of a subbituminous coal with certain binary organic solvent mixtures have been studied at 250/sup 0/C. Mixtures of pyridine, quinoline, piperidine, tetrahydroquinoline, and ethylenediamine with either toluene or tetralin were contacted with coal in a successive batch, stirred reactor, the extractions being carried to near completion. Two distinct behaviors of extraction yield as a function of composition have been identified. In the majority of the solvent mixtures the extraction yield increases linearly with increasing concentration of the more active solvent. When the active solvent is ethylenediamine, however, the extraction yield increases rapidly when small concentrations of ethylenediamine are used but then levels out close to its maximum value in a 50 to 50 mix. This behavior is an indication that, except in the case of ethylenediamine, the activity of solvent mixtures is a function of bulk solution properties.

  11. Measurement and prediction of aromatic solute distribution coefficients for aqueous-organic solvent systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.R.; Luthy, R.G.

    1984-06-01

    Experimental and modeling activities were performed to assess techniques for measurement and prediction of distribution coefficients for aromatic solutes between water and immiscible organic solvents. Experiments were performed to measure distribution coefficients in both clean water and wastewater systems, and to assess treatment of a wastewater by solvent extraction. The theoretical portions of this investigation were directed towards development of techniques for prediction of solute-solvent/water distribution coefficients. Experiments were performed to assess treatment of a phenolic-laden coal conversion wastewater by solvent extraction. The results showed that solvent extraction for recovery of phenolic material offered several wastewater processing advantages. Distribution coefficients were measured in clean water and wastewater systems for aromatic solutes of varying functionality with different solvent types. It was found that distribution coefficients for these compounds in clean water systems were not statistically different from distribution coefficients determined in a complex coal conversion process wastewater. These and other aromatic solute distribution coefficient data were employed for evaluation of modeling techniques for prediction of solute-solvent/water distribution coefficients. Eight solvents were selected in order to represent various chemical classes: toluene and benzene (aromatics), hexane and heptane (alkanes), n-octanol (alcohols), n-butyl acetate (esters), diisopropyl ether (ethers), and methylisobutyl ketone (ketones). The aromatic solutes included: nonpolar compounds such as benzene, toluene and naphthalene, phenolic compounds such as phenol, cresol and catechol, nitrogenous aromatics such as aniline, pyridine and aminonaphthalene, and other aromatic solutes such as naphthol, quinolinol and halogenated compounds. 100 references, 20 figures, 34 tables.

  12. Mapping the surface of Escherichia coli peptide deformylase by NMR with organic solvents.

    Science.gov (United States)

    Byerly, Douglas W; McElroy, Craig A; Foster, Mark P

    2002-07-01

    Identifying potential ligand binding sites on a protein surface is an important first step for targeted structure-based drug discovery. While performing control experiments with Escherichia coli peptide deformylase (PDF), we noted that the organic solvents used to solubilize some ligands perturbed many of the same resonances in PDF as the small molecule inhibitors. To further explore this observation, we recorded (15)N HSQC spectra of E. coli peptide deformylase (PDF) in the presence of trace quantities of several simple organic solvents (acetone, DMSO, ethanol, isopropanol) and identified their sites of interaction from local perturbation of amide chemical shifts. Analysis of the protein surface structure revealed that the ligand-induced shift perturbations map to the active site and one additional surface pocket. The correlation between sites of solvent and inhibitor binding highlights the utility of organic solvents to rapidly and effectively validate and characterize binding sites on proteins prior to designing a drug discovery screen. Further, the solvent-induced perturbations have implications for the use of organic solvents to dissolve candidate ligands in NMR-based screens.

  13. Quality Improvement of a Small Water Supply. A Practical Application of a Full System of Nanofiltration

    Directory of Open Access Journals (Sweden)

    R. Marin Galvin

    2013-04-01

    Full Text Available The THM level in the Spanish drinking water is limited to less than 0.100 mg/L, due to its potential toxicological effect on humans. This paper investigates the comparison of the results obtained in a small supply of water that historically presented THM contents out of the Spanish normative, versus the results there obtained when the treatment was modified with the inclusion of a nanofiltration system. So, the conventional treatment first applied was that of pre-oxidation with chlorine and/or KMnO4, followed by coagulation with aluminum salts directly on closed sand filter, and disinfection final by chlorination: with this system, THM levels lower than 0.100 mg/L were not always secured. Thus, to improve the water quality, a full system of nanofiltration was implemented, after the above treatment, consisting in: pre-filtration through cartridges, filtration over activated carbon, post-filtration for retaining impurities, and finally, nanofiltration and chlorination of water after nanofiltration. In this order, the new treatment scheme has usually produced water with maximum THM levels of 0.058 mg/L, and average values of 0.013 mg/L, 0.30 mg/L for organic matter concentrations, and water always microbiologically pure. Also, the contents of Fe, Mn and Al in the treated water were significantly reduced with respect to the previous situation without nanofiltration.

  14. Effect of Exposure to a Mixture of Organic Solvents on Hearing Thresholds in Petrochemical Industry Workers

    Directory of Open Access Journals (Sweden)

    Ziba Loukzadeh

    2014-10-01

    Full Text Available Introduction: Hearing loss is one of the most common occupational diseases. In most workplaces, workers are exposed to noise and solvents simultaneously, so the potential risk of hearing loss due to solvents may be attributed to noise.  In this study we aimed to assess the effect of exposure to mixed aromatic solvents on hearing in the absence of exposure to hazardous noise.   Materials and Methods: In a cross-sectional study, 99 workers from the petrochemical industry with exposure to a mixture of organic solvents whose noise exposure was lower than 85 dBA were compared with 100 un-exposed controls. After measuring sound pressure level and mean concentration of each solvent in the workplace, pure-tone-audiometry was performed and the two groups were compared in terms of high-frequency and low-frequency hearing loss. T-tests and Chi-square tests were used to compare the two groups.   Results: The mean hearing threshold at all frequencies among petrochemical workers was normal (below 25 dB. We did not observe any significant association between solvent exposure and high-frequency or low-frequency hearing loss.   Conclusion:  This study showed that temporary exposure (less than 4 years to a mixture of organic solvents, without exposure to noise, does not affect workers’ hearing threshold in audiometry tests.

  15. Non-Hodgkin's lymphoma risk derived from exposure to organic solvents: a review of epidemiologic studies

    Directory of Open Access Journals (Sweden)

    Rêgo Marco Antônio V.

    1998-01-01

    Full Text Available The rate of non-Hodgkin's lymphomas (NHL has increased around the world during the last decades. Apart from the role of the human immunodeficiency virus (HIV infection in the development of NHL, exposure to chemical agents like phenoxyacetic pesticides, hair dyes, metal fumes and organic solvents are suspected to be involved. The present review evaluates the results of studies that directly or indirectly searched for an association between solvent exposure and NHL. The selected studies comprised those published from 1979 to 1997, designed to investigate risk factors for NHL, whether specifically looking for solvent exposure or for general risks in which solvent exposure could be included. In 25 of the 45 reviewed studies (55.5%, fifty-four statistically significant associations between NHL and solvent exposure related occupations or industries were reported. Statistical significance was more frequently shown in studies where solvent exposure was more accurately defined. In eighteen of such studies, 13 (72.2% defined or suggested organic solvents as possible risk factors for NHL.

  16. Non-Hodgkin's lymphoma risk derived from exposure to organic solvents: a review of epidemiologic studies

    Directory of Open Access Journals (Sweden)

    Marco Antônio V. Rêgo

    Full Text Available The rate of non-Hodgkin's lymphomas (NHL has increased around the world during the last decades. Apart from the role of the human immunodeficiency virus (HIV infection in the development of NHL, exposure to chemical agents like phenoxyacetic pesticides, hair dyes, metal fumes and organic solvents are suspected to be involved. The present review evaluates the results of studies that directly or indirectly searched for an association between solvent exposure and NHL. The selected studies comprised those published from 1979 to 1997, designed to investigate risk factors for NHL, whether specifically looking for solvent exposure or for general risks in which solvent exposure could be included. In 25 of the 45 reviewed studies (55.5%, fifty-four statistically significant associations between NHL and solvent exposure related occupations or industries were reported. Statistical significance was more frequently shown in studies where solvent exposure was more accurately defined. In eighteen of such studies, 13 (72.2% defined or suggested organic solvents as possible risk factors for NHL.

  17. Effect of exposure to a mixture of organic solvents on hearing thresholds in petrochemical industry workers.

    Science.gov (United States)

    Loukzadeh, Ziba; Shojaoddiny-Ardekani, Ahmad; Mehrparvar, Amir Houshang; Yazdi, Zohreh; Mollasadeghi, Abolfazl

    2014-10-01

    Hearing loss is one of the most common occupational diseases. In most workplaces, workers are exposed to noise and solvents simultaneously, so the potential risk of hearing loss due to solvents may be attributed to noise. In this study we aimed to assess the effect of exposure to mixed aromatic solvents on hearing in the absence of exposure to hazardous noise. In a cross-sectional study, 99 workers from the petrochemical industry with exposure to a mixture of organic solvents whose noise exposure was lower than 85 dBA were compared with 100 un-exposed controls. After measuring sound pressure level and mean concentration of each solvent in the workplace, pure-tone-audiometry was performed and the two groups were compared in terms of high-frequency and low-frequency hearing loss. T-tests and Chi-square tests were used to compare the two groups. The mean hearing threshold at all frequencies among petrochemical workers was normal (below 25 dB). We did not observe any significant association between solvent exposure and high-frequency or low-frequency hearing loss. This study showed that temporary exposure (less than 4 years) to a mixture of organic solvents, without exposure to noise, does not affect workers' hearing threshold in audiometry tests.

  18. Preparation of Some Novel Copper(I) Complexes and their Molar Conductances in Organic Solvents

    Science.gov (United States)

    Gill, Dip Singh; Rana, Dilbag

    2009-04-01

    Attempts have been made to prepare some novel copper(I) nitrate, sulfate, and perchlorate complexes. Molar conductances of these complexes have been measured in organic solvents like acetonitrile (AN), acetone (AC), methanol (MeOH), N,N-dimethylformamide (DMF), N,Ndimethylacetamide (DMA), and dimethylsulfoxide (DMSO) at 298 K. The molar conductance data have been analyzed to obtain limiting molar conductances (λ0) and ion association constants (KA) of the electrolytes. The results showed that all these complexes are strong electrolytes in all organic solvents. The limiting ionic molar conductances (λo± ) for various ions have been calculated using Bu4NBPh4 as reference electrolyte. The actual radii for copper(I) complex ions are very large and different in different solvents and indicate some solvation effects in each solvent system

  19. Structure of Solvent-Free Nanoparticle−Organic Hybrid Materials

    KAUST Repository

    Yu, Hsiu-Yu

    2010-11-16

    We derive the radial distribution function and the static structure factor for the particles in model nanoparticleorganic hybrid materials composed of nanoparticles and attached oligomeric chains in the absence of an intervening solvent. The assumption that the oligomers form an incompressible fluid of bead-chains attached to the particles that is at equilibrium for a given particle configuration allows us to apply a density functional theory for determining the equilibrium configuration of oligomers as well as the distribution function of the particles. A quasi-analytic solution is facilitated by a regular perturbation analysis valid when the oligomer radius of gyration R g is much greater than the particle radius a. The results show that the constraint that each particle carries its own share of the fluid attached to itself yields a static structure factor that approaches zero as the wavenumber approaches zero. This result indicates that each particle excludes exactly one other particle from its neighborhood. © 2010 American Chemical Society.

  20. Oxidative Desulfurization of Gasoline by Ionic Liquids Coupled with Extraction by Organic Solvents

    OpenAIRE

    Abro, Rashid; Gao, Shurong; Chen, Xiaochun; Yu, Guangren; Abdeltawab, Ahmed A.; Al-Deyab, Salem S.

    2016-01-01

    In this work, desulfurization of real fluidized catalytic cracking (FCC) gasoline was investigated in dual steps; first in oxidative desulfurization (ODS) using imidazolium and pyrrolidonium based Brønsted acidic ionic liquids (ILs) as solvent and catalyst and hydrogen peroxide as oxidant. In second step, extractive desulfurization took place using organic solvents of furfural, furfural alcohol and ethylene glycol. Variety of factors such as temperature, time, mass ratio of oil/ILs and regene...

  1. Green analytical chemistry - the use of surfactants as a replacement of organic solvents in spectroscopy

    Science.gov (United States)

    Pharr, Daniel Y.

    2017-07-01

    This chapter gives an introduction to the many practical uses of surfactants in analytical chemistry in replacing organic solvents to achieve greener chemistry. Taking a holistic approach, it covers some background of surfactants as chemical solvents, their properties and as green chemicals, including their environmental effects. The achievements of green analytical chemistry with micellar systems are reviewed in all the major areas of analytical chemistry where these reagents have been found to be useful.

  2. Measurements and correlation of viscosities and conductivities for the mixtures of ethylammonium nitrate with organic solvents

    International Nuclear Information System (INIS)

    Litaeim, Yousra; Zarrougi, Ramzi; Dhahbi, Mahmoud

    2009-01-01

    Room temperature ionic liquids (IL) as a new class of organic molten salts have been considered as an alternative of traditional organic solvents (OS). The physico-chemical transport properties of mixtures IL/OS were investigated and described by ion-ion, ion solvent and solvent-solvent interactions. Ethylammonium nitrate (EAN) was studied in presence of two types of organic solvents: the dimethyl carbonate (DMC) and the formamide (FA). The variation of the viscosity with salt concentration and temperature shows that EAN ions behave as a structure breaker for the DMC. However, no effect was recorded in the case of FA. Concentrated electrolyte solutions behave as very structured media and checked a theory of pseudo-lattice. The existence of a conductivity maximum indicates two competing effects; the increasing number of charge carriers and the higher viscosity of the electrolyte as the salt concentration was raised. The use of the Walden product to investigate ionic interactions of EAN with both solvents was discussed. A study of the effect of temperature on the conductivity and viscosity reveals that both systems (EAN/DMC and EAN/FA) obey an Arrhenius low. The activation energies for the tow transport process (Ea,L and Ea,h) as a function of the salt concentration were evaluated.

  3. Impaired colour vision in workers exposed to organic solvents: A systematic review.

    Science.gov (United States)

    Betancur-Sánchez, A M; Vásquez-Trespalacios, E M; Sardi-Correa, C

    2017-01-01

    To evaluate recent evidence concerning the relationship between the exposure to organic solvents and the impairment of colour vision. A bibliographic search was conducted for scientific papers published in the last 15 years, in the LILACS, PubMed, Science Direct, EBSCO, and Cochrane databases that included observational studies assessing the relationship between impairment in colour vision and exposure to organic solvents. Eleven studies were selected that were performed on an economically active population and used the Lanthony D-15 desaturated test (D-15d), measured the exposure to organic solvents, and included unexposed controls. It was found that there is a statistically significant relationship between the exposure to organic solvents and the presence of an impairment in colour vision. The results support the hypothesis that exposure to organic solvents could induce acquired dyschromatopsia. The evaluation of colour vision with the D-15d test is simple and sensitive for diagnosis. More studies need to be conducted on this subject in order to better understand the relationship between impaired colour vision and more severe side effects caused by this exposure. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. 40 CFR Table 4 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction... formulation data. Solvent type Average organic HAP mass fraction Typical organic HAP, percent by mass...

  5. Electroviscous Effects in Ceramic Nanofiltration Membranes.

    Science.gov (United States)

    Farsi, Ali; Boffa, Vittorio; Christensen, Morten Lykkegaard

    2015-11-16

    Membrane permeability and salt rejection of a γ-alumina nanofiltration membrane were studied and modeled for different salt solutions. Salt rejection was predicted by using the Donnan-steric pore model, in which the extended Nernst-Planck equation was applied to predict ion transport through the pores. The solvent flux was modeled by using the Hagen-Poiseuille equation by introducing electroviscosity instead of bulk viscosity. γ-Alumina particles were used for ζ-potential measurements. The ζ-potential measurements show that monovalent ions did not adsorb on the γ-alumina surface, whereas divalent ions were highly adsorbed. Thus, for divalent ions, the model was modified, owing to pore shrinkage caused by ion adsorption. The ζ-potential lowered the membrane permeability, especially for membranes with a pore radius lower than 3 nm, a ζ-potential higher than 20 mV, and an ionic strength lower than 0.01 m. The rejection model showed that, for a pore radius lower than 3 nm and for solutions with ionic strengths lower than 0.01 m, there is an optimum ζ-potential for rejection, because of the concurrent effects of electromigration and convection. Hence, the model can be used as a prediction tool to optimize membrane perm-selectivity by designing a specific pore size and surface charge for application at specific ionic strengths and pH levels. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Sugar-Based Polyamides: Self-Organization in Strong Polar Organic Solvents.

    Science.gov (United States)

    Rosu, Cornelia; Russo, Paul S; Daly, William H; Cueto, Rafael; Pople, John A; Laine, Roger A; Negulescu, Ioan I

    2015-09-14

    Periodic patterns resembling spirals were observed to form spontaneously upon unassisted cooling of d-glucaric acid- and d-galactaric acid-based polyamide solutions in N-methyl-N-morpholine oxide (NMMO) monohydrate. Similar observations were made in d-galactaric acid-based polyamide/ionic liquid (IL) solutions. The morphologies were investigated by optical, polarized light and confocal microscopy assays to reveal pattern details. Differential scanning calorimetry was used to monitor solution thermal behavior. Small- and wide-angle X-ray scattering data reflected the complex and heterogeneous nature of the self-organized patterns. Factors such as concentration and temperature were found to influence spiral dimensions and geometry. The distance between rings followed a first-order exponential decay as a function of polymer concentration. Fourier-Transform Infrared Microspectroscopy analysis of spirals pointed to H-bonding between the solvent and the pendant hydroxyl groups of the glucose units from the polymer backbone. Tests on self-organization into spirals of ketal-protected d-galactaric acid polyamides in NMMO monohydrate confirmed the importance of the monosaccharide's pendant free hydroxyl groups on the formation of these patterns. Rheology performed on d-galactaric-based polyamides at high concentration in NMMO monohydrate solution revealed the optimum conditions necessary to process these materials as fibers by spinning. The self-organization of these sugar-based polyamides mimics certain biological materials.

  7. Use of high-boiling point organic solvents for pulping oil palm empty fruit bunches.

    Science.gov (United States)

    Rodríguez, Alejandro; Serrano, Luis; Moral, Ana; Pérez, Antonio; Jiménez, Luis

    2008-04-01

    Oil palm empty fruit bunches were used as an alternative raw material to obtain cellulosic pulp. Pulping was done by using high-boiling point organic solvents of decreased polluting power relative to classical (Kraft, sulphite) solvents but affording operation at similar pressure levels. The holocellulose, alpha-cellulose and lignin contents of oil palm empty fruit bunches (viz. 66.97%, 47.91% and 24.45%, respectively) are similar to those of some woody raw materials such as pine and eucalyptus, and various non-wood materials including olive tree prunings, wheat straw and sunflower stalks. Pulping tests were conducted by using ethyleneglycol, diethyleneglycol, ethanolamine and diethanolamine under two different sets of operating conditions, namely: (a) a 70% solvent concentration, 170 degrees C and 90 min; and (b) 80% solvent, 180 degrees C and 150 min. The solid/liquid ratio was six in both cases. The amine solvents were found to provide pulp with better properties than did the glycol solvents. Ethanolamine pulp exhibited the best viscosity and drainage index (viz. 636 mL/g and 17 degrees SR, respectively), and paper made from it the best breaking length (1709 m), stretch (1.95%), burst index (0.98 kN/g) and tear index (0.33 mNm(2)/g). Operating costs can be reduced by using milder conditions, which provide similar results. In any case, the amines are to be preferred to the glycols as solvents for this purpose.

  8. Solvent-resistant organic transistors and thermally stable organic photovoltaics based on cross-linkable conjugated polymers

    KAUST Repository

    Kim, Hyeongjun

    2012-01-10

    Conjugated polymers, in general, are unstable when exposed to air, solvent, or thermal treatment, and these challenges limit their practical applications. Therefore, it is of great importance to develop new materials or methodologies that can enable organic electronics with air stability, solvent resistance, and thermal stability. Herein, we have developed a simple but powerful approach to achieve solvent-resistant and thermally stable organic electronic devices with a remarkably improved air stability, by introducing an azide cross-linkable group into a conjugated polymer. To demonstrate this concept, we have synthesized polythiophene with azide groups attached to end of the alkyl chain (P3HT-azide). Photo-cross-linking of P3HT-azide copolymers dramatically improves the solvent resistance of the active layer without disrupting the molecular ordering and charge transport. This is the first demonstration of solvent-resistant organic transistors. Furthermore, the bulk-heterojunction organic photovoltaics (BHJ OPVs) containing P3HT-azide copolymers show an average efficiency higher than 3.3% after 40 h annealing at an elevated temperature of 150 °C, which represents one of the most thermally stable OPV devices reported to date. This enhanced stability is due to an in situ compatibilizer that forms at the P3HT/PCBM interface and suppresses macrophase separation. Our approach paves a way toward organic electronics with robust and stable operations. © 2011 American Chemical Society.

  9. Effects of organic solvents on hyaluronic acid nanoparticles obtained by precipitation and chemical crosslinking.

    Science.gov (United States)

    Bicudo, Rafaela Costa Souza; Santana, Maria Helena Andrade

    2012-03-01

    Hyaluronic acid is a hydrophilic mucopolysaccharide composed of alternating units of D-glucuronic acid and N-acetylglucosamine. It is used in many medical, pharmaceutical, and cosmetic applications, as sponges, films, or particle formulations. Hyaluronic acid nanoparticles can be synthesized free of oil and surfactants by nanoprecipitation in organic solvents, followed by chemical crosslinking. The organic solvent plays an important role in particles size and structure. Therefore, this study aimed to investigate the influence of acetone, ethanol, and isopropyl alcohol on the synthesis and physico-chemical properties of hyaluronic acid nanoparticles. Particles were crosslinked with adipic hydrazide and chloride carbodiimide under controlled conditions. The nanoparticles obtained with all three studied solvents were moderately electrostatically stable. Experiments with acetone produced the smallest particle size (120.44 nm) and polydispersity (0.27). The size and polydispersity of hyaluronic acid nanoparticles correlated with the surface tension between water and the organic solvents, not with the thermodynamic affinity of water for the organic solvents.

  10. Crosslinked copolyazoles with a zwitterionic structure for organic solvent resistant membranes

    KAUST Repository

    Chisca, Stefan

    2015-01-01

    The preparation of crosslinked membranes with a zwitterionic structure based on a facile reaction between a newly synthesized copolyazole with free OH groups and (3-glycidyloxypropyl)trimethoxysilane (GPTMS) is reported. The new OH-functionalized copolyazole is soluble in common organic solvents, such as tetrahydrofuran (THF), dimethylsulfoxide (DMSO), N,N′-dimethylformamide (DMF) and N-methyl-2-pyrrolidone (NMP) and can be easily processed by phase inversion. After crosslinking with GPTMS, the membranes acquire high solvent resistance. We show the membrane performance and the influence of the crosslinking reaction conditions on the thermal stability, surface polarity, pore morphology, and solvent resistance. By using UV-spectroscopy we monitored the solvent resistance of the membranes in four aggressive solvents (THF, DMSO, DMF and NMP) for 30 days. After this time, only minor changes (less than 2%) were detected for membranes subjected to a crosslinking reaction for 6 hours or longer. Our data suggest that the novel crosslinked membranes can be used for industrial applications in wide harsh environments in the presence of organic solvents.

  11. Plasma-polymerized films providing selective affinity to the polarity of vaporized organic solvents

    International Nuclear Information System (INIS)

    Akimoto, Takuo; Ikeshita, Yusuke; Terashima, Ryo; Karube, Isao

    2009-01-01

    Plasma-polymerized films (PPFs) were fabricated as recognition membranes for a vapor-sensing device, and their affinity to vaporized organic solvents was evaluated with surface plasmon resonance. The affinity we intended to create is the selective sorption of the vaporized organic solvents depending on their polarity. For this purpose, acetonitrile, ethylenediamine (EDA), styrene, hexamethyldisiloxane (HMDSO), and hexamethyldisilazane were used to fabricate PPFs. Vaporized methanol, ethanol, and 1-propanol were used as high-polar solvents to be analyzed. Hexane, toluene, and p-xylene were used as low-polar solvents. As a result, the HMDSO-PPF with 97.3 o of contact angle was found to provide affinity to the low-polar solvents. In contrast, the EDA-PPF with 7.1 o of contact angle provided affinity to the high-polar solvents. Observations of the surface morphology of the HMDSO- and EDA-PPFs with a scanning electron microscope revealed that they are composed of nano-scale islands.

  12. Measurement and correlation of solubility of ciclesonide in seven pure organic solvents

    International Nuclear Information System (INIS)

    Zhou, Lina; Yin, Qiuxiang; Guo, Zhiqiang; Lu, Haijiao; Liu, Mingyan; Chen, Wei; Hou, Baohong

    2017-01-01

    Highlights: • The solubility of ciclesonide in seven pure organic solvents was determined by gravimetric method. • The solubility order was interpreted by virtue of density function theory (DFT). • The experimental solubility of ciclesonide was correlated by four thermodynamic models. • Mixing thermodynamic properties of ciclesonide were calculated and discussed. - Abstract: The solubility of ciclesonide in seven organic solvents (ethanol, 2-propanol, 1-propanol, 1-butanol, acetonitrile, toluene and ethyl acetate) in the temperature range from 278.15 K to 313.15 K was measured by gravimetrical method under atmospheric pressure. The results indicate that the solubility of ciclesonide increases with elevating temperature in all investigated solvents. The solubility order in different solvents was interpreted through comparing interaction force between solute and solvent molecules by virtue of density function theory (DFT). Thermodynamic equations including the modified Apelblat equation, λh equation, Wilson equation and NRTL equation are all suitable to correlate the solubility results. Based on the Wilson equation, the thermodynamic parameters from the mixing process are calculated, and the results indicate the mixing process of ciclesonide in the selected pure solvents is spontaneous and entropy-driven.

  13. Organic solvents, electrolytes, and lithium ion cells with good low temperature performance

    Science.gov (United States)

    Smart, Marshall C. (Inventor); Bugga, Ratnakumar V. (Inventor); Surampudi, Subbarao (Inventor); Huang, Chen-Kuo (Inventor)

    2002-01-01

    Multi-component organic solvent systems, electrolytes and electrochemical cells characterized by good low temperature performance are provided. In one embodiment, an improved organic solvent system contains a ternary mixture of ethylene carbonate, dimethyl carbonate and diethyl carbonate. In other embodiments, quaternary systems include a fourth component, i.e, an aliphatic ester, an asymmetric alkyl carbonate or a compound of the formula LiOX, where X is R, COOR, or COR, where R is alkyl or fluoroalkyl. Electrolytes based on such organic solvent systems are also provided and contain therein a lithium salt of high ionic mobility, such as LiPF.sub.6. Reversible electrochemical cells, particularly lithium ion cells, are constructed with the improved electrolytes, and preferably include a carbonaceous anode, an insertion type cathode, and an electrolyte interspersed therebetween.

  14. Renal effects of chronic exposure to organic solvents. A clinical controlled trial

    Energy Technology Data Exchange (ETDEWEB)

    Krusell, L.; Nielsen, H.K.; Baelum, J.; Lundqvist, G.; Omland, O.; Vaeth, M.; Husted, S.E.; Mogensen, C.E.; Geday, E.

    1985-01-01

    Chronic effects of organic solvents on renal function were measured by creatinine clearances and urinary excretion rates of beta 2-microglobulin and albumin. Forty-three male printing trade workers occupationally exposed to different organic solvents for 9-25 years were compared with 43 age-matched male controls. No differences were found either in creatinine clearances or average basal levels of beta 2-microglobulin and albumin excretion rates, whereas a positive relation could be demonstrated between alcohol consumption on the day before the trial and urinary excretion rate of albumin. This investigation did not reveal any adverse renal effects of moderate chronic exposure to organic solvents in a group of active trade workers.

  15. Renal effects of chronic exposure to organic solvents. A clinical controlled trial

    DEFF Research Database (Denmark)

    Krusell, Lars Romer; Nielsen, H K; Bælum, Jesper

    1985-01-01

    Chronic effects of organic solvents on renal function were measured by creatinine clearances and urinary excretion rates of beta 2-microglobulin and albumin. Forty-three male printing trade workers occupationally exposed to different organic solvents for 9-25 years were compared with 43 age......-matched male controls. No differences were found either in creatinine clearances or average basal levels of beta 2-microglobulin and albumin excretion rates, whereas a positive relation could be demonstrated between alcohol consumption on the day before the trial and urinary excretion rate of albumin....... This investigation did not reveal any adverse renal effects of moderate chronic exposure to organic solvents in a group of active trade workers....

  16. Effect of Contemporary Exposure to Mixed Organic Solvents and Occupational Noise on Hearing Thresholds of Workers

    Directory of Open Access Journals (Sweden)

    Attarchi Mir Saeid

    2010-03-01

    Full Text Available Background: Mixed organic solvent exposure, as well as noise, has a wide spread in different industries. In recent years it has been propounded that simultaneous exposure to mixed organic solvents and occupational noise can establish a hearing loss that is more severe than hearing loss due to exposure to each of them separately.Materials & Methods: A descriptive- analytic study was conducted during 2008 in an automobile industry on 441 employees in three different groups. First group were assembly workers that only exposed to noise. The second group included employees in new painting saloon that exposed not only to noise but also to permissible levels of mixed organic solvents and the third group were employees in old painting saloon that exposed to noise and mixed organic solvents in more than threshold limit value (TLV level. The prevalence of hearing loss was compared between three groups on the basis of model 1 (mean hearing threshold in frequencies 0.5, 1 and 2 KHz more than 25dB and model 2 (mean hearing threshold in frequencies 3, 4, 6 and 8 KHz more than 25dB. Results: According to model 2, in workers exposed to noise in addition to mixed organic solvents, the rate of hearing loss, was significantly higher than workers exposed to noise alone (P<0.05, even after adjusting for confounding variables using logistic regression analysis (OR= 4.12 , P<0.001.Conclusion: In workers with simultaneous exposure to mixed organic solvents and noise, special attention must be paid to accurate accomplishment of hearing conservation programs including doing audiometric exams in shorter periods and take advantage of hearing protection devices with higher noise reduction rate (NRR.

  17. High-Throughput Synthetic Chemistry Enabled by Organic Solvent Disintegrating Tablet.

    Science.gov (United States)

    Li, Tingting; Xu, Lei; Xing, Yanjun; Xu, Bo

    2017-01-17

    Synthetic chemistry remains a time- and labor-intensive process of inherent hazardous nature. Our organic solvent disintegrating tablet (O-Tab) technology has shown potential to make industrial/synthetic chemistry more efficient. As is the case with pharmaceutical tablets, our reagent-containing O-Tabs are mechanically strong, but disintegrate rapidly when in contact with reaction media (organic solvents). For O-Tabs containing sensitive chemicals, they can be further coated to insulate them from air and moisture. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Diffusion and solubility coefficients determined by permeation and immersion experiments for organic solvents in HDPE geomembrane.

    Science.gov (United States)

    Chao, Keh-Ping; Wang, Ping; Wang, Ya-Ting

    2007-04-02

    The chemical resistance of eight organic solvents in high density polyethylene (HDPE) geomembrane has been investigated using the ASTM F739 permeation method and the immersion test at different temperatures. The diffusion of the experimental organic solvents in HDPE geomembrane was non-Fickian kinetic, and the solubility coefficients can be consistent with the solubility parameter theory. The diffusion coefficients and solubility coefficients determined by the ASTM F739 method were significantly correlated to the immersion tests (pHDPE as barriers in the field.

  19. Enzymatic Synthesis of Esculin Ester in Ionic Liquids Buffered with Organic Solvents

    DEFF Research Database (Denmark)

    Hu, Yifan; Guo, Zheng; Lue, Bena-Marie

    2009-01-01

    The enzymatic esterification of esculin catalyzed by Candida antarctica lipase B (Novozym 435) was carried out in ionic liquid (IL)-organic solvent mixed systems in comparison with individual systems. The reaction behaviors in IL-organic solvents were systemically evaluated using acetone as a model...... in IL-acetone mixtures made it possible to improve the solubility of esculin while the effects of ILs on lipase activity were minimized. Following the benignity of ILs to lipase activity, the anions of ILs were ranked in the order as [Tf2N](-) > [PF6](-) > [BF4](-) > [CF3SO3](-) > [C4F9SO3](-) > [TAF...

  20. Azeotropic binary solvent mixtures for preparation of organic single crystals

    NARCIS (Netherlands)

    Li, X.; Kjellander, B.K.C.; Anthony, J.E.; Bastiaansen, C.W.M.; Broer, D.J.; Gelinck, G.H.

    2009-01-01

    Here, a new approach is introduced to prepare large single crystals of π-conjugated organic molecules from solution. Utilizing the concept of azeotropism, single crystals of tri-isopropylsilylethynyl pentacene (TIPS-PEN) with dimensions up to millimeters are facilely self-assembled from homogeneous

  1. Azeotropic binary solvent mixtures for preparation of organic single crystals

    NARCIS (Netherlands)

    Li, X.; Kjellander, B.K.C.; Anthony, J.E.; Bastiaansen, C.W.M.; Broer, D.J.; Gelinck, G.H.

    2009-01-01

    Here, a new approach is introduced to prepare large single crystals of p-conjugated organic molecules from solution. Utilizing the concept of azeotropism, single crystals of tri-isopropylsilylethynyl pentacene (TIPS-PEN) with dimensions up to millimeters are facilely self-assembled from homogeneous

  2. Prioritizing substitution of organic solvents in industrial cleaning processes

    DEFF Research Database (Denmark)

    Rasmussen, Pia Brunn; Jacobsen, Thomas

    1997-01-01

    A method for prioritizing the substitution of volatile organic compounds (VOC) used in industrial cleaning processes is developed. The result is a matrix, which, if all information can be obtained, gives a comprehensive description of the effects, exposure and emission of VOC, as well as the pros...

  3. Nanofiltration Membranes for Removal of Color and Pathogens in Small Public Drinking Water Sources

    Science.gov (United States)

    Small public water supplies that use surface water as a source for drinking water are frequently faced with elevated levels of color and natural organic matter (NOM) that are precursors for chlorinated disinfection byproduct (DBP) formation. Nanofiltration (NF) systems can preve...

  4. 40 CFR Table 4 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in the... Solvent type Averageorganic HAP mass fraction Typical organic HAP, percent by mass Aliphatic b 0.03 1...

  5. 40 CFR Table 5 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction... formulation data: Solvent type Averageorganic HAP mass fraction Typical organic HAP, percent by mass Aliphatic...

  6. 40 CFR Table 4 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in the.... Solvent type Averageorganic HAP mass fraction Typical organic HAP, percent by mass Aliphatic b 0.03 1...

  7. Mn(II)-coordinated Fluorescent Carbon Dots: Preparation and Discrimination of Organic Solvents

    Science.gov (United States)

    Wang, Yuru; Wang, Tianren; Chen, Xi; Xu, Yang; Li, Huanrong

    2018-04-01

    Herein, we prepared a Mn(II)-coordinated carbon dots (CDs) with fluorescence and MRI (magnetic resonance imaging) bimodal properties by a one-pot solvothermal method and separated via silica column chromatography. The quantum yield of the CDs increased greatly from 2.27% to 6.75% with increase of Mn(II) doping, meanwhile the CDs exhibited a higher MR activity (7.28 mM-1s-1) than that of commercial Gd-DTPA (4.63 mM-1s-1). In addition, white light emitting CDs were obtained by mixing the different types of CDs. Notably, these CDs exhibited different fluorescence emissions in different organic solvents and could be used to discriminate organic solvents based on the polarity and protonation of the solvents.

  8. Psychophysical Evaluation of Achromatic and Chromatic Vision of Workers Chronically Exposed to Organic Solvents

    International Nuclear Information System (INIS)

    Lacerda, E.M.D.B.; Lima, M.G.; Silveira, L.C.D.S.; Rodrigues, A.R.; Teixeira, C.E.C.; De Lima, L.J.B.; Silveira, L.C.D.S.; Ventura, D.F.; Ventura, D.F.

    2012-01-01

    The purpose of this paper was to evaluate achromatic and chromatic vision of workers chronically exposed to organic solvents through psychophysical methods. Thirty-one gas station workers (31.5 ± 8.4 years old) were evaluated. Psychophysical tests were achromatic tests (Snellen chart, spatial and temporal contrast sensitivity, and visual perimetry) and chromatic tests (Ishihara's test, color discrimination ellipses, and Farnsworth-Munsell 100 hue test FM100). Spatial contrast sensitivities of exposed workers were lower than the control at spatial frequencies of 20 and 30 cpd whilst the temporal contrast sensitivity was preserved. Visual field losses were found in 10-30 degrees of eccentricity in the solvent exposed workers. The exposed workers group had higher error values of FM100 and wider color discrimination ellipses area compared to the controls. Workers occupationally exposed to organic solvents had abnormal visual functions, mainly color vision losses and visual field constriction

  9. Lipophilic polyelectrolyte gel derived from phosphonium borate can absorb a wide range of organic solvents.

    Science.gov (United States)

    Sunaga, Sokuro; Kokado, Kenta; Sada, Kazuki

    2018-01-24

    Herein, we demonstrate a polyelectrolyte gel which can absorb a wide range of organic solvents from dimethylsulfoxide (DMSO, permittivity: ε = 47.0) to tetrahydrofuran (ε = 5.6). The gel consists of polystyrene chains with small amounts (∼5 mol%) of lipophilic electrolytes derived from triphenylphosphonium tetraaryl borate. The swelling ability of the polyelectrolyte gel was higher than that of the alkyl ammonium tetraaryl borate previously reported by us, and this is attributed to the higher compatibility with organic solvents, as well as the higher dissociating ability, of the triphenyl phosphonium salt. The role of the ionic moieties was additionally confirmed by post modification of the polyelectrolyte gel via a conventional Wittig reaction, resulting in a nonionic gel. Our findings introduced here will lead to a clear-cut molecular design for polyelectrolyte gels which absorb all solvents.

  10. Thermal decomposition of organic solvent with nitric acid in nuclear fuel reprocessing plants

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Tadao; Nishio, Gunji; Takada, Junichi; Tukamoto, Michio; Watanabe, Kouji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Miyata, Sadaichirou

    1995-02-01

    Since a thermal decomposition of organic solvent containing TBP (tributyl phosphate) with nitric acid and heavy metal nitrates is an exothermic reaction, it is possible to cause an explosive decomposition of TBP-complex materials formed by a nitration between the solvent and nitric acid, if the solvent involving TBP-complex is heated upto a thermal limit in an evaporator to concentrate a fuel liquid solution from the extraction process in the reprocessing plant. In JAERI, the demonstration test for explosive decomposition of TBP-complex by the nitration was performed to elucidate the safety margin of the evaporator in the event of hypothetical explosion under auspices of the Science and Technology Agency. The demonstration test was carried out by heating TBP/n-dodecane solvent mixed with nitric acid and uranium nitrate. In the test, the thermal decomposition behavior of the solvent was examined, and also a kinematic reaction constant and a heat formation of the TBP-complex decomposition were measured by the test. In the paper, a safety analysis of a model evaporator was conducted during accidental conditions under the explosive decomposition of the solvent. (author).

  11. Determination of water traces in various organic solvents using Karl Fischer method under FIA conditions.

    Science.gov (United States)

    Dantan, N; Frenzel, W; Küppers, S

    2000-05-31

    Flow injection methods utilising the Karl Fischer (KF) reaction with spectrophotometric and potentiometric detection are described for the determination of the trace water content in various organic solvents. Optimisation of the methods resulted in an accessible (linear) working range of 0.01-0.2% water for many solvents studied with a typical precision of 1-2% R.S.D. Only 50 mul of organic solvent was injected and the sampling frequency was about 120 samples per h. Since the slopes of the calibration curves were different for different solvents appropriate calibration was required. Problems associated with spectrophotometric detection and caused by refractive index changes were pointed out and a nested-loop configuration was proposed to overcome this kind of interference. The potentiometric method with a novel flow-through detector cell was shown to surpass the performance of spectrophotometric detection in any respect. The characteristics of the procedures developed made them well applicable for on-line monitoring of technical solvent distillations in an industrial plant.

  12. Remediation of soils, sediments and sludges by extraction with organic solvents

    NARCIS (Netherlands)

    Noordkamp, E.R.

    1999-01-01

    Remediation of contaminated soils, sediments and sludges by extraction with organic solvents is still in the initial stages of development. So far hardly any scientific research has been carried out into this approach. Therefore, the main objective of the present investigation was to study

  13. "Chemistry in a spinneret" to fabricate hollow fibers for organic solvent filtration

    NARCIS (Netherlands)

    Dutczak, S.M.; Tanardi, Cheryl; Kopec, K.K.; Wessling, Matthias; Stamatialis, Dimitrios

    2012-01-01

    Organic solvent filtration (OSF) is a very efficient separation technique with high potential in many branches of industry. Currently the choice of the commercial membranes is limited only to a few flat sheet membranes and spiral wound modules. It is generally known that a membrane in hollow fiber

  14. Response Mechanisms in Serratia marcescens IBBPo15 During Organic Solvents Exposure.

    Science.gov (United States)

    Stancu, Mihaela Marilena

    2016-12-01

    Serratia marcescens strain IBB Po15 (KT315653) which possesses serratiopeptidase (ser) gene (KT894207) exhibited good solvent tolerance. During the exposure of S. marcescens IBB Po15 cells to 5 % organic solvents, n-decane was less toxic for this bacterium, compared with n-hexane, cyclohexane, ethylbenzene, toluene, and styrene. The exposure of the S. marcescens IBB Po15 cells to n-hexane, cyclohexane, ethylbenzene, toluene, and styrene induced the formation of large clusters, while in control and n-decane-exposed cells, only organization into small clusters was observed. The data obtained suggested that S. marcescens IBB Po15 cells produced some secondary metabolites (i.e., surfactant serrawettin, red pigment prodigiosin) which are well known as valuable molecules due to their large applications. The exposure of the bacterial cells to organic solvents induced secondary metabolites profile modifications. However, S. marcescens IBB Po15 possesses only alkB1, todM, rhlAB, pswP, mpr, and ser genes, the unspecific amplification of other fragments being acquired also when the primers for alkM1, xylM, ndoM, and C23DO genes were used. Modifications of DNA patterns were not depicted in S. marcescens IBB Po15 cells exposed to organic solvents.

  15. Aggregation behavior of cholic acid derivatives in organic solvents and in water

    NARCIS (Netherlands)

    Willemen, H.M.

    2002-01-01

    In this thesis various cholic acid derivatives are reported that display aggregation in water or in organic solvents. Spontaneous aggregation of single molecules into larger, ordered structures occurs at the borderline of solubility. Amphiphilic compounds, or surfactants, which possess a

  16. Subcritical wet air oxidation of organic solvents and chelating agents of the nuclear fuel

    International Nuclear Information System (INIS)

    Bachir, Souley

    1999-01-01

    This document deals with the environment control, more specially organic solvents and chelating agents destruction, employed in the nuclear industry. This work details the subcritical wet air oxidation process. Another part of the document deals with the possible coupling between this process and the biodegradation technic in the framework of the sewage sludges treatment. (A.L.B.)

  17. Solvent-Free Wittig Reaction: A Green Organic Chemistry Laboratory Experiment

    Science.gov (United States)

    Leung, Sam H.; Angel, Stephen A.

    2004-01-01

    Some Wittig reactions can be carried out by grinding the reactants in a mortar with a pestle for about 20 minutes, as per investigation. A laboratory experiment involving a solvent-free Wittig reaction that can be completed in a three-hour sophomore organic chemistry laboratory class period, are developed.

  18. Cochlear condition and olivocochlear system of gas station attendants exposed to organic solvents

    Directory of Open Access Journals (Sweden)

    Tochetto, Tania Maria

    2012-01-01

    Full Text Available Introduction: Organic solvents have been increasingly studied due to its ototoxic action. Objective: Evaluate the conditions of outer hair cells and olivocochlear system in individuals exposed to organic solvents. Method: This is a prospective study. 78 gas station attendants exposed to organic solvents had been evaluated from three gas stations from Santa Maria city, Rio Grande do Sul (RS. After applying the inclusion criteria, the sample was constituted by 24 individuals. The procedures used on the evaluation were audiological anamnesis, Transient otoacoustic emissions (TEOAES and research for the suppressive effect of TEOAES. A group control (GC compounded by 23 individuals was compared to individuals exposed and non-exposed individuals. The data collection has been done in the room of Speech Therapy of Workers Health Reference Center of Santa Maria. Results: The TEOAES presence was major in the left ear in both groups; the average relation of TEOAES signal/noise in both ears was greater in GE; the TEOAES suppressive effect in the right ear was higher in the individual of GE (62,5% and in the left ear was superior in GC (86,96%, with statistically significant difference. The median sign/noise ratio of TEOAES, according to the frequency range, it was higher in GC in three frequencies ranges in the right ear and one in the left ear. Conclusion: It was not found signs of alteration on the outer hair cells neither on the olivocochlear medial system in the individuals exposed to organic solvents.

  19. Large-scale enzymatic production of natural flavour esters in organic solvent with continuous water removal.

    Science.gov (United States)

    Gubicza, L; Kabiri-Badr, A; Keoves, E; Belafi-Bako, K

    2001-11-30

    A new, large-scale process was developed for the enzymatic production of low molecular weight flavour esters in organic solvent. Solutions for the elimination of substrate and product inhibitions are presented. The excess water produced during the process was continuously removed by hetero-azeotropic distillation and esters were produced at yields of over 90%.

  20. Conformational isomerism of phenolic procyanidins: preferred conformations in organic solvents and water

    Science.gov (United States)

    Tsutomu Hatano; Richard W. Hemingway

    1997-01-01

    NMR studies of catechin-{4α→8)-epicatechin (I) and catechin-{4α→8)-catechin (2) provided complete assignment of the proton and carbon resonances for both the more extended and compact conformers in the free phenolic form. When 1 is in organic solvents, the more extended rotamer is preferred over the more compact rotamer (10:7), but...

  1. Morphology versus Vertical Phase Segregation in Solvent Annealed Small Molecule Bulk Heterojunction Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Alexander Kovalenko

    2015-01-01

    Full Text Available The deep study of solvent annealed small molecules bulk heterojunction organic solar cells based on DPP(TBFu2 : PC60BM blend is carried out. To reveal the reason of the solvent annealing advantage over the thermal one, capacitance-voltage measurements were applied. It was found that controlling the vertical phase segregation in the solar cells a high fullerene population in the vicinity of the cathode could be achieved. This results in increase of the shunt resistance of the cell, thus improving the light harvesting efficiency.

  2. Substitution of Organic Solvents - a Way to improve Working Environment and reduce Emissions to the Atmosphere

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    1996-01-01

    solvents as cleaning agents has been reached. However, some barriers to this substitution process, are found outside the printing companies. In designing of machines and auxiliary equipment, the manufacturers must take into account, that cleaning with non-volatile agents should be possible. Even a rather...... the process in order to omit the solvents or to use water-based products. In cases, where a change to water-based is not evident, improvements can be reached by using non-volatile, low-toxic products, typically esters of fatty acids from vegetable oils. In offset printing a drastic reduction of use of organic...

  3. Mass transfer coefficient of slug flow for organic solvent-aqueous system in a microreactor

    Energy Technology Data Exchange (ETDEWEB)

    Tuek, Ana Jurinjak; Anic, Iva; Kurtanjek, Zelimir; Zelic, Bruno [University of Zagreb, Zagreb (Croatia)

    2015-06-15

    Application of microreactor systems could be the next break-through in the intensification of chemical and biochemical processes. The common flow regime for organic solvent-aqueous phase two-phase systems is a segmented flow. Internal circulations in segments cause high mass transfer and conversion. We analyzed slug flow in seven systems of organic solvents and aqueous phase. To analyze how slug lengths in tested systems depend on linear velocity and physical and chemical properties of used organic solvents, regression models were proposed. It was shown that models based on linearization of approximation by potentials give low correlation for slug length prediction; however, application of an essential nonlinear model of multiple layer perception (MLP) neural network gives high correlation with R{sup 2}=0.9. General sensitivity analysis was applied for the MLP neural network model, which showed that 80% of variance in slug length for the both phases is accounted for the viscosity and density of the organic phases; 10% is accounted by surface tension of the organic phase, while molecular masses and flow rates each account for 5%. For defined geometry of microreactor, mass transfer has been determined by carrying out the neutralization experiment with NaOH where acetic acid diffuses from organic phase (hexane) into aqueous phase. Estimated mass transfer coefficients were in the range k{sub L}a=4,652-1,9807 h{sup -1}.

  4. Mass transfer coefficient of slug flow for organic solvent-aqueous system in a microreactor

    International Nuclear Information System (INIS)

    Tuek, Ana Jurinjak; Anic, Iva; Kurtanjek, Zelimir; Zelic, Bruno

    2015-01-01

    Application of microreactor systems could be the next break-through in the intensification of chemical and biochemical processes. The common flow regime for organic solvent-aqueous phase two-phase systems is a segmented flow. Internal circulations in segments cause high mass transfer and conversion. We analyzed slug flow in seven systems of organic solvents and aqueous phase. To analyze how slug lengths in tested systems depend on linear velocity and physical and chemical properties of used organic solvents, regression models were proposed. It was shown that models based on linearization of approximation by potentials give low correlation for slug length prediction; however, application of an essential nonlinear model of multiple layer perception (MLP) neural network gives high correlation with R 2 =0.9. General sensitivity analysis was applied for the MLP neural network model, which showed that 80% of variance in slug length for the both phases is accounted for the viscosity and density of the organic phases; 10% is accounted by surface tension of the organic phase, while molecular masses and flow rates each account for 5%. For defined geometry of microreactor, mass transfer has been determined by carrying out the neutralization experiment with NaOH where acetic acid diffuses from organic phase (hexane) into aqueous phase. Estimated mass transfer coefficients were in the range k L a=4,652-1,9807 h -1

  5. Haematological and biochemical pattern in occupational organic solvent poisoning and exposure

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, L M; Rasmussen, J M

    1982-12-01

    A haematological and biochemical investigation was undertaken in 122 consecutive male patients with suspected organic solvent poisoning due to exposure to a mixture of organic solvents such as turpentine, toluene and xylene. Sixty-four healthy solvent exposed and 91 healthy non-exposed male volunteers were used as controls. The only statistically significant differences were that in the patients (B)-leucocytes and S-creatinine were lower than in the controls. (B)-monocytes were higher in all exposed groups than in the controls. S-creatine kinase was higher in patients actually exposed at the examination time, than in all other groups. It is concluded that there was no characteristic haematological and biochemical pattern that could be of value in the individual diagnosis of organic solvent poisoning. The patients and the controls were seen as out-patients. In all groups studied, more than 10% of the results of reticulocytes, leucocytes, sedimentaition rate, orosomucoid and creatine kinase exceeded the upper level of the reference interval, which is based on in-patients. New reference intervals for these 5 analyses, valid for ambulantly examined subjects, should be worked out.

  6. Extraction of Betulin, Trimyristin, Eugenol and Carnosic Acid Using Water-Organic Solvent Mixtures

    Directory of Open Access Journals (Sweden)

    Fulgentius N. Lugemwa

    2012-08-01

    Full Text Available A solvent system consisting of ethyl acetate, ethyl alcohol and water, in the volume ratio of 4.5:4.5:1, was developed and used to extract, at room temperature, betulin from white birch bark and antioxidants from spices (rosemary, thyme, sage, and oregano and white oak chips. In addition, under reflux conditions, trimyristin was extracted from nutmeg using the same solvent system, and eugenol from olives was extracted using a mixture of salt water and ethyl acetate. The protocol demonstrates the use of water in organic solvents to extract natural products from plants. Measurement of the free-radical scavenging activity using by 2,2-diphenyl-1-picrylhydrazyl (DPPH indicated that the extraction of plant material using ethyl acetate, ethyl alcohol and water (4.5:4.5:1, v/v/v was exhaustive when carried out at room temperature for 96 h.

  7. Anomalous Capacitance Maximum of the Glassy Carbon-Ionic Liquid Interface through Dilution with Organic Solvents.

    Science.gov (United States)

    Bozym, David J; Uralcan, Betül; Limmer, David T; Pope, Michael A; Szamreta, Nicholas J; Debenedetti, Pablo G; Aksay, Ilhan A

    2015-07-02

    We use electrochemical impedance spectroscopy to measure the effect of diluting a hydrophobic room temperature ionic liquid with miscible organic solvents on the differential capacitance of the glassy carbon-electrolyte interface. We show that the minimum differential capacitance increases with dilution and reaches a maximum value at ionic liquid contents near 5-10 mol% (i.e., ∼1 M). We provide evidence that mixtures with 1,2-dichloroethane, a low-dielectric constant solvent, yield the largest gains in capacitance near the open circuit potential when compared against two traditional solvents, acetonitrile and propylene carbonate. To provide a fundamental basis for these observations, we use a coarse-grained model to relate structural variations at the double layer to the occurrence of the maximum. Our results reveal the potential for the enhancement of double-layer capacitance through dilution.

  8. Investigations of the Effects of Biocide Dosing and Chemical Cleaning on the Organic Carbon Removal in an Integrated Ultrafiltration - Nanofiltration Desalination Pilot Plant

    KAUST Repository

    Khojah, Bayan A.

    2017-01-01

    drawbacks of membrane desalination is membrane fouling. It decreases the performance of the membranes and increases the energy requirement. Two of the most important causes of fouling are microbes and organic matter. Hence, to maintain an optimized

  9. Nitrate removal through combination of nanofiltration and electrocatalysis; Nitratentfernung durch Kombination von Nanofiltration und Elektrokatalyse

    Energy Technology Data Exchange (ETDEWEB)

    Roehricht, M.; Stadlbauer, E.A.; Happel, H. [Fachhochschule Giessen (Germany). Zentrum fuer Umwelttechnik

    1999-07-01

    In a new process combination, nitrate-containing ground water is first of all separated by nanofiltration into a concentrate stream (some 25 %) and a largely nitrate-free permeate (75 %). Then the enriched nitrate in the concentrate is converted into nitrogen by means of electrocatalytic nitrate reduction. Whereas, in nanofiltration, a concentration takes place, electrocatalytic nitrate reduction is a process by which nitrate is converted into elemental nitrogen and, thus, removed. Nanofiltration is a membrane separating process making use of 'open' reverse osmosis membranes, which are characterized by high flow but also reduced retention. (orig.) [German] In einer neuen Verfahrenskombination wird das nitrathaltige Grundwasser zuerst durch Nanofiltration in einen Konzentratstrom (ca. 25%) und ein weitgehend nitratfreies Permeat (75%) aufgeteilt. Im Konzentrat wird dann mittels Elektrokatalytischer Nitratreduktion (EKN) das angereicherte Nitrat zu Stickstoff umgewandelt. Waehrend bei der Nanofiltration eine Aufkonzentrierung erfolgt, wird durch die Elektrokatalytische Nitratreduktion das Nitrat in elementaren Stickstoff umgewandelt und so entfernt. Die Nanofiltration ist ein Membrantrennverfahren, bei dem 'offene' Umkehrosmosemembranen eingesetzt werden, die einen hohen Fluss aber auch eine verminderte Rueckhaltung aufweisen. (orig.)

  10. High-yield exfoliation of graphene using ternary-solvent strategy for detecting volatile organic compounds

    Science.gov (United States)

    Zhang, Shao-Lin; Zhang, Zhijun; Yang, Woo-Chul

    2016-01-01

    Despite the great progress in the theory and experimental verification we made in past decade, the practical application of graphene is still hindered by the lack of efficient, economical, scalable, ease-processing exfoliation method. Herein, we propose a facile, low-cost, and efficient liquid-phase exfoliation process using low boiling-temperature solvent mixture to fabricate few-layer graphene in large scale. The Hansen solubility parameter theory was applied to help optimize the composition of solvent mixture. Aqueous-based ternary-solvent mixture, for the first time, was adapted to exfoliate graphene. We demonstrate that the exfoliation efficiency using ternary-solvent mixture surpasses that from binary-solvent approach. The final product concentration after optimization was over 260 μg/ml. The concentrated graphene dispersion was used to fabricate gas sensor for detecting volatile organic gases. Taking advantage of large surface area, large number of adsorption sites, and well-preserved basal plane, the mass-produced graphene nanosheets exhibited promising sensing potential toward ethanol and methanol vapors.

  11. [Analysis of organic solvent poisonings occurring in Japan from 1995 to 2006].

    Science.gov (United States)

    Maki, Syou; Nawata, Hideki; Ogawa, Yasutaka

    2011-01-01

    Statistical analyses based on incidence rate were carried out for organic solvent poisonings occurring in Japan. We used the published data of "Typical cases of occupational diseases" and "Current situation of occupational disease occurrence" in the "Industrial Hygiene Guidebook (Roudoueisei no Shiori)". The number of workers as a population of occupational solvent handlers was obtained from the Ministry of Health, Labour and Welfare, Japan. The annual incidences of solvent poisoning from 1995 to 2006, poisoning, death-by-poisoning, and secondary poisoning were 3.3-5.4, 0.0-0.83, and 0.0-0.34 cases/(100,000 solvent handlers × yr), respectively. Annual incidence classified by manufacturing, construction, and other services were 2.5, 52.0, and 6.1, respectively. Manufacturing showed a small increase from 1999 to 2003, and stopped increasing after 2004. Construction had a peak in 2000. Other services notably decreased from 14.4 in 1999 to 2.5 in 2006. The monthly distribution of the number of poisoning cases was prominent in January. Annual incidences of poisoning, death-by-poisoning, and secondary poisoning were 3.9, 0.5, 0.2 for toluene, 3.5, 0.5, 0.3 for xylene, and 16.4, 4.7, 2.3 for trichloroethylene, respectively. The annual incidences classified by industry and solvents showed no change for manufacturing, whereas that for construction notably decreased from 88.6 in 2000 to 12.0 in 2006.

  12. Relation between the interfacial tension in an organic solvent-water system and the parameters of the solvating capacity of the solvent

    International Nuclear Information System (INIS)

    Nikitin, S.D.; Shmidt, V.S.

    1987-01-01

    It was shown that there is a linear relation between the empirical DE (diluent effect) and E/sub T/ parameters, which characterize the solvating capacity of the solvent, and the interfacial tension in an organic solvent-water two-phase system. Analysis of the sample correlation coefficients shows that the relation between the interfacial tension and the DE parameters of the solvents is closer to linear than the corresponding relation for the E/sub T/ parameters. During analysis of the data for 31 solvents it was established that the largest inverse correlation coefficient r = -0.98 is obtained with an equation of the DE = a + bσ/rho 1/3, type, were a and b are constants, and rho is the density of the solvent. The regression equation has the following form: DE = 7.586 - 0.147 σ/rho 1/3. Since the interfacial activity of hydrophobic surfactants decreases linearly with increase in the DE values, it follows from the obtained equation that decrease of the interfacial tension at the water-organic solvent interface must lead to a decrease in the interfacial activity of hydrophobic surfactants present in the system

  13. Insights into the effects of solvent properties in graphene based electric double-layer capacitors with organic electrolytes

    Science.gov (United States)

    Zhang, Shuo; Bo, Zheng; Yang, Huachao; Yang, Jinyuan; Duan, Liangping; Yan, Jianhua; Cen, Kefa

    2016-12-01

    Organic electrolytes are widely used in electric double-layer capacitors (EDLCs). In this work, the microstructure of planar graphene-based EDLCs with different organic solvents are investigated with molecular dynamics simulations. Results show that an increase of solvent polarity could weaken the accumulation of counter-ions nearby the electrode surface, due to the screen of electrode charges and relatively lower ionic desolvation. It thus suggests that solvents with low polarity could be preferable to yield high EDL capacitance. Meanwhile, the significant effects of the size and structure of solvent molecules are reflected by non-electrostatic molecule-electrode interactions, further influencing the adsorption of solvent molecules on electrode surface. Compared with dimethyl carbonate, γ-butyrolactone, and propylene carbonate, acetonitrile with relatively small-size and linear structure owns weak non-electrostatic interactions, which favors the easy re-orientation of solvent molecules. Moreover, the shift of solvent orientation in surface layer, from parallel orientation to perpendicular orientation relative to the electrode surface, deciphers the solvent twin-peak behavior near negative electrode. The as-obtained insights into the roles of solvent properties on the interplays among particles and electrodes elucidate the solvent influences on the microstructure and capacitive behavior of EDLCs using organic electrolytes.

  14. MOLECULAR DYNAMICS SIMULATION OF KINETIC RESOLUTION OF RACEMIC ALCOHOL USING BURKHOLDERIA CEPACIA LIPASE IN ORGANIC SOLVENTS

    Directory of Open Access Journals (Sweden)

    A. C. Mathpati

    2018-03-01

    Full Text Available Lipases, a subclass of hydrolases, have gained a lot of importance as they can catalyze esterification, transesterification and hydrolysis reaction in non-aqueous media. Lipases are also widely used for kinetic resolution of racemic alcohols into enantiopure compounds. The lipase activity is affected by organic solvents due to changes in the conformational rigidity of enzymes, the active site, or altering the solvation of the transition state. The activity of lipases strongly depends on the logP value of solvents. Molecular dynamics (MD can help to understand the effect of solvents on lipase conformation as well as protein-ligand complex. In this work, MD simulations of Burkholderia cepacia lipase (BCL and complex between R and S conformation of acetylated form of 1-phenylethanol with BCL using gromacs have been carried in various organic solvents. The RMSD values were within the range of 0.15 to 0.20 nm and radius of gyration was found to be with 1.65 to 1.9 nm. Major changes in the B factor compared to reference structure were observed between residues 60 to 80, 120 to 150 and 240 to 260. Higher unfolding was observed in toluene and diethyl ether compared to hexane and acetonitrile. R acetylated complex was found to favorably bind BCL compared to S form. The predicted enantioselectivity were in good agreement with the experimental data.

  15. Role of α-Helical Structure in Organic Solvent-Activated Homodimer of Elastase Strain K

    Directory of Open Access Journals (Sweden)

    Chee Fah Wong

    2011-09-01

    Full Text Available Recombinant elastase strain K overexpressed from E. coli KRX/pCon2(3 was purified to homogeneity by a combination of hydrophobic interaction chromatography and ion exchange chromatography, with a final yield of 48% and a 25-fold increase in specific activity. The purified protein had exhibited a first ever reported homodimer size of 65 kDa by SDS-PAGE and MALDI-TOF, a size which is totally distinct from that of typically reported 33 kDa monomer from P. aeruginosa. The organic solvent stability experiment had demonstrated a stability pattern which completely opposed the rules laid out in previous reports in which activity stability and enhancement were observed in hydrophilic organic solvents such as DMSO, methanol, ethanol and 1-propanol. The high stability and enhancement of the enzyme in hydrophilic solvents were explained from the view of alteration in secondary structures. Elastinolytic activation and stability were observed in 25 and 50% of methanol, respectively, despite slight reduction in α-helical structure caused upon the addition of the solvent. Further characterization experiments had postulated great stability and enhancement of elastase strain K in broad range of temperatures, pHs, metal ions, surfactants, denaturing agents and substrate specificity, indicating its potential application in detergent formulation.

  16. Effect of organic solvents on desorption and atomic absorption determination of heavy metal ions after ion exchange concentration

    International Nuclear Information System (INIS)

    Pilipenko, A.T.; Safronova, V.G.; Zakrevskaya, L.V.

    1986-01-01

    The effect of organic solvents (acetone, methylethylketone, dioxane, ethanol) on desorption of Cu, Mn, Co, Cd, Zn, Pb, Ni from cationite KU-23 ion exchange resin and on the detection limits of their atomic absorption determination has been examined. Cobalt and cadmium can be separated quantitatively using desorption by a mixture of HCl and acetone. Addition of an organic solvent results in a higher absorbance, mainly due to a high rate and efficiency of atomization. Acetone has proved to be the best solvent: addition of 60 vol. % of this solvent to the concentrate provides 2 times lower detection limits for the heavy metas in water

  17. Isolation, identification and characterization of organic solvent tolerant protease from Bacillus sp. DAF-01

    Directory of Open Access Journals (Sweden)

    Arastoo Badoei-Dalfard

    2012-01-01

    Full Text Available Introduction: Organic solvent-tolerant bacteria are relatively novel extermophilic microorganisms, which can produce organic tolerant protease with capacity of being used in industrial biotechnology for producing high-value compounds. Therefore, finding of these bacteria has drawn much researchers attention nowadays. Materials and Methods: In this project, samples were collected from a hot spring, located in Jiroft. Samples were incubated in medium supplemented with cyclohexane and toluene for 3 days. Screening of protease producing bacteria was performed on the specific media, SKM (Skim milk agar, based on clear area diameter. The best bacterium was identified based on 16s rDNA gene. Protease activity was considered in different temperatures, pH and organic solvents.Results: Sequence alignment and phylogenetic tree results showed that this bacteria was closely related to Bacillus niacini, with 97% homology. Enzymatic studies showed that, this enzyme was active at a wide range of temperatures, 20-90 °C and it,s optimal activity was in 60 °C. In addition, maximum protease activity was obtained in the 8-9 range of pH, and optimal stability was also at pH 9.0. Protease activity in the presence of methanol, toluene, isopropanol, cyclohexane and DMF ‏showed that, remaining activity was at least 80% compared to the control (without organic solvent Discussion and Conclusion: Thermopilic capacity, being active in alkaline protease and high protease stability in the presence of organic solvents all herald a remarkable application for using in different industries.

  18. Bioproduction of vanillin using an organic solvent-tolerant Brevibacillus agri 13.

    Science.gov (United States)

    Wangrangsimagul, Nuttawat; Klinsakul, Kunticha; Vangnai, Alisa S; Wongkongkatep, Jirarut; Inprakhon, Pranee; Honda, Kohsuke; Ohtake, Hisao; Kato, Junichi; Pongtharangkul, Thunyarat

    2012-01-01

    Nowadays, majority of vanillin supplied to the world market is chemically synthesized from a petroleum-based raw material, raising a concern among the consumers regarding the product safety. In this study, an organic solvent-tolerant Brevibacillus agri 13 previously reported for a strong predilectic property was utilized as a whole-cell biocatalyst for bioproduction of vanillin from isoeugenol (IG). B. agri 13 is the first biocatalyst reported for bioproduction of vanillin at a temperature as high as 45°C. Both pH and temperature were found to affect vanillin production significantly. An extreme level of organic solvent tolerance of B. agri 13 allowed us to utilize it in a biphasic system using organic solvents generally considered as highly toxic to most bacteria. With an addition of butyl acetate at 30% (v/v) as an organic second phase, toxicity of IG exerted onto the biocatalyst was reduced dramatically while faster and more efficient vanillin production was obtained (1.7 g/L after 48 h with 27.8% molar conversion).

  19. Method of estimating changes in vapor concentrations continuously generated from two-component organic solvents.

    Science.gov (United States)

    Hori, Hajime; Ishidao, Toru; Ishimatsu, Sumiyo

    2010-12-01

    We measured vapor concentrations continuously evaporated from two-component organic solvents in a reservoir and proposed a method to estimate and predict the evaporation rate or generated vapor concentrations. Two kinds of organic solvents were put into a small reservoir made of glass (3 cm in diameter and 3 cm high) that was installed in a cylindrical glass vessel (10 cm in diameter and 15 cm high). Air was introduced into the glass vessel at a flow rate of 150 ml/min, and the generated vapor concentrations were intermittently monitored for up to 5 hours with a gas chromatograph equipped with a flame ionization detector. The solvent systems tested in this study were the methanoltoluene system and the ethyl acetate-toluene system. The vapor concentrations of the more volatile component, that is, methanol in the methanol-toluene system and ethyl acetate in the ethyl acetate-toluene system, were high at first, and then decreased with time. On the other hand, the concentrations of the less volatile component were low at first, and then increased with time. A model for estimating multicomponent organic vapor concentrations was developed, based on a theory of vapor-liquid equilibria and a theory of the mass transfer rate, and estimated values were compared with experimental ones. The estimated vapor concentrations were in relatively good agreement with the experimental ones. The results suggest that changes in concentrations of two-component organic vapors continuously evaporating from a liquid reservoir can be estimated by the proposed model.

  20. Influence of organic solvent treatment on elasticoluminescent property of europium-doped strontium aluminates

    International Nuclear Information System (INIS)

    Fujio, Yuki; Xu, Chao-Nan; Terasaki, Nao; Ueno, Naohiro

    2014-01-01

    The influence of an organic solvent treatment on elasticoluminescent (ELS) characteristics of mechanoluminescent (ML) sensor using the composite film consisting of an ELS material and epoxy resin was investigated. We used strontium aluminate doped with a small amount of europium (SrAl 2 O 4 :Eu, SAOE) as an ELS material in this study. After evaluating the ELS characteristics of the fabricated ML sensors using SAOE treated with/without various organic solvents, SAOE treated with methanol and ethanol showed lower ELS intensities than that of untreated SAOE. In contrast, the ELS response curves against strain for the ML sensors using SAOE treated with acetone and toluene, overlapped with that of untreated SAOE. From the characterization of SAOE treated with alcohols, such as methanol and ethanol, we can hypothesize that poor ELS characteristics is due to the degradation of the SAOE grain surfaces by the hydrolyze reaction of SAOE with hydroxyl group of alcohol. Thus, on the basis of the obtained results, we can conclude that the selection of organic solvent used in the preparation of SAOE film is of considerable importance in the development of ML sensor with a highly-reliable ELS characteristic. -- Highlights: • Influence of organic solution treatment on the sensing characteristics of a mechanoluminescent (ML) sensor using SrAl 2 O 4 :Eu has been investigated. • An alcohol treatment of SAOE powder has considerable effect on its ML characteristic. • There is almost no influence of acetone and toluene treatments on ML characteristics

  1. Improving the industrial production of 6-APA: enzymatic hydrolysis of penicillin G in the presence of organic solvents.

    Science.gov (United States)

    Abian, Olga; Mateo, César; Fernández-Lorente, Gloria; Guisán, José M; Fernández-Lafuente, Roberto

    2003-01-01

    The hydrolysis of penicillin G in the presence of an organic solvent, used with the purpose of extracting it from the culture medium, may greatly simplify the industrial preparation of 6-APA. However, under these conditions, PGA immobilized onto Eupergit displays very low stability (half-life of 5 h in butanone-saturated water) and a significant degree of inhibition by the organic solvent (30%). The negative effect of the organic solvent strongly depended on the type of solvent utilized: water saturated with butanone (around 28% v/v) had a much more pronounced negative effect than that of methylisobutyl ketone (MIBK) (solubility in water was only 2%). These problems were sorted out by using a new penicillin G acylase derivative designed to work in the presence of organic solvents (with each enzyme molecule surrounded by an hydrophilic artificial environment) and a suitable organic solvent (MIBK). Using such solvent, this derivative kept its activity unaltered for 1 week at 32 degrees C. Moreover, the enzyme activity was hardly inhibited by the presence of the organic solvent. In this way, the new enzyme derivative thus prepared enables simplification of the industrial hydrolysis of penicillin G.

  2. Direct measurement for organic solvents diffusion using ultra-sensitive optical resonator

    Science.gov (United States)

    Ali, Amir R.; Elias, Catherine M.

    2017-06-01

    In this paper, novel techniques using ultra-sensitive chemical optical sensor based on whispering gallery modes (WGM) are proposed through two different configurations. The first one will use a composite micro-sphere, when the solvent interacts with the polymeric optical sensors through diffusion the sphere start to swallow that solvent. In turn, that leads to change the morphology and mechanical properties of the polymeric spheres. Also, these changes could be measured by tracking the WGM shifts. Several experiments were carried out to study the solvent induced WGM shift using microsphere immersed in a solvent atmosphere. It can be potentially used for sensing the trace organic solvents like ethanol and methanol. The second configuration will use a composite beam nitrocellulose composite (NC) structure that acts as a sensing element. In this configuration, a beam is anchored to a substrate in one end, and the other end is compressing the polymeric sphere causing a shift in its WGM. When a chemical molecule is attached to the beam, the resonant frequency of the cantilever will be changed for a certain amount. By sensing this certain resonant frequency change, the existence of a single chemical molecule can be detected. A preliminary experimental model is developed to describe the vibration of the beam structure. The resonant frequency change of the cantilever due to attached mass is examined imperially using acetone as an example. Breath diagnosis can use this configuration in diabetic's diagnosis. Since, solvent like acetone concentration in human breath leads to a quick, convenient, accurate and painless breath diagnosis of diabetics. These micro-optical sensors have been examined using preliminary experiments to fully investigate its response. The proposed chemical sensor can achieve extremely high sensitivity in molecular level.

  3. Volumetric Properties of the Ionic Liquid, 1-Butyl-3-methylimidazolium Tetrafluoroborate, in Organic Solvents at T = 298.15K

    Science.gov (United States)

    Shekaari, Hemayat; Zafarani-Moattar, Mohammed Taghi

    2008-04-01

    Apparent molar volumes, V_φ , and compressibilities, kappa _φ , of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]) have been determined from precise density and speed-of-sound measurements in organic solvents, methanol (MeOH), acetonitrile (MeCN), tetrahydrofuran (THF), N, N-dimethylacetamide (DMA), and dimethylsulfoxide (DMSO) in the dilute region of the ionic liquid. Corresponding values at infinite dilution are estimated by the Redlich-Mayer and Pitzer equations. The results have been interpreted by the interaction of the [BMIm][BF4] in the organic solvents. Results show that the structure and dielectric constant of the organic solvents play an important role for the ion-solvent interactions in these mixtures. It was found that the strength of interaction between [BMIm][BF4] with the studied organic solvents has the order DMSO > DMA > MeOH > MeCN > THF.

  4. Mesoporous silica nanotubes hybrid membranes for functional nanofiltration

    International Nuclear Information System (INIS)

    El-Safty, Sherif A; Shahat, Ahmed; Mekawy, Moataz; Nguyen, Hoa; Warkocki, Wojciech; Ohnuma, Masato

    2010-01-01

    The development of nanofiltration systems would greatly assist in the production of well-defined particles and biomolecules with unique properties. We report a direct, simple synthesis of hexagonal silica nanotubes (NTs), which vertically aligned inside anodic alumina membranes (AAM) by means of a direct templating method of microemulsion phases with cationic surfactants. The direct approach was used as soft templates for predicting ordered assemblies of surfactant/silica composites through strong interactions within AAM pockets. Thus, densely packed NTs were successfully formed in the entirety of the AAM channels. These silica NTs were coated with layers of organic moieties to create a powerful technique for the ultrafine filtration. The resulting modified-silica NTs were chemically robust and showed affinity toward the transport of small molecular particles. The rigid silica NTs inside AAM channels had a pore diameter of ≤ 4 nm and were used as ultrafine filtration systems for noble metal nanoparticles (NM NPs) and semiconductor nanocrystals (SC NCs) fabricated with a wide range of sizes (1.0-50 nm) and spherical/pyramidal morphologies. Moreover, the silica NTs hybrid membranes were also found to be suitable for separation of biomolecules such as cytochrome c (CytC). Importantly, this nanofilter design retains high nanofiltration efficiency of NM NPs, SC NCs and biomolecules after a number of reuse cycles. Such retention is crucial in industrial applications.

  5. Dimethoate and atrazine retention from aqueous solution by nanofiltration membranes.

    Science.gov (United States)

    Ahmad, A L; Tan, L S; Shukor, S R Abd

    2008-02-28

    In order to produce sufficient food supply for the ever-increasing human population, pesticides usage is indispensable in the agriculture sector to control crop losses. However, the effect of pesticides on the environment is very complex as undesirable transfers occur continually among different environmental sections. This eventually leads to contamination of drinking water source especially for rivers located near active agriculture practices. This paper studied the application of nanofiltration membrane in the removal of dimethoate and atrazine in aqueous solution. Dimethoate was selected as the subject of study since it is being listed as one of the pesticides in guidelines for drinking water by World Health Organization. Nevertheless, data on effectiveness of dimethoate rejection using membranes has not been found so far. Meanwhile, atrazine is classified as one of the most commonly used pesticides in Malaysia. Separation was done using a small batch-type membrane separation cell with integrated magnetic stirrer while concentration of dimethoate and atrazine in aqueous solution was analyzed using high performance liquid chromatography (HPLC). Four nanofiltration membranes NF90, NF200, NF270 and DK were tested for their respective performance to separate dimethoate and atrazine. Of all four membranes, NF90 showed the best performance in retention of dimethoate and atrazine in water.

  6. Thermal reduction of graphene-oxide-coated cotton for oil and organic solvent removal

    International Nuclear Information System (INIS)

    Hoai, Nguyen To; Sang, Nguyen Nhat; Hoang, Tran Dinh

    2017-01-01

    Highlights: • A new method for preparation of reduced-graphene-oxide (RGO) coated cotton is proposed. • The RGO-Cotton composites were carefully characterized using many modern techniques. • RGO-Cotton exhibited superhydrophobicity and superolephilicity. • RGO-Cotton sponges can absorb many types of oils and organic solvents and can be recycled. - Abstract: The reduced-graphene-oxide (RGO)-coated cotton sponge (RGO-Cot) was prepared by simply heating a graphene-oxide (GO)-coated cotton sponge, which was fabricated by dipping a commercial cotton sponge into a GO dispersion, under vacuum at 200 °C for 2 h. The thus prepared RGO-Cot sponges exhibited superhydrophobicity and superoleophilicity, with a water contact angle of 151°. These RGO-Cot sponges could be used for removal of many types of oils and organic solvents as they exhibit absorption capacities in the range of 22–45 times their weight and good absorption recyclability.

  7. Thermal reduction of graphene-oxide-coated cotton for oil and organic solvent removal

    Energy Technology Data Exchange (ETDEWEB)

    Hoai, Nguyen To, E-mail: hoaito@pvu.edu.vn; Sang, Nguyen Nhat; Hoang, Tran Dinh

    2017-02-15

    Highlights: • A new method for preparation of reduced-graphene-oxide (RGO) coated cotton is proposed. • The RGO-Cotton composites were carefully characterized using many modern techniques. • RGO-Cotton exhibited superhydrophobicity and superolephilicity. • RGO-Cotton sponges can absorb many types of oils and organic solvents and can be recycled. - Abstract: The reduced-graphene-oxide (RGO)-coated cotton sponge (RGO-Cot) was prepared by simply heating a graphene-oxide (GO)-coated cotton sponge, which was fabricated by dipping a commercial cotton sponge into a GO dispersion, under vacuum at 200 °C for 2 h. The thus prepared RGO-Cot sponges exhibited superhydrophobicity and superoleophilicity, with a water contact angle of 151°. These RGO-Cot sponges could be used for removal of many types of oils and organic solvents as they exhibit absorption capacities in the range of 22–45 times their weight and good absorption recyclability.

  8. Electroenzymatic Reactions With Oxygen on Laccase-Modified Electrodes in Anhydrous (Pure) Organic Solvent

    DEFF Research Database (Denmark)

    Yarapolov, A.; Shleev, S.; Zaitseva, E.

    2007-01-01

    in two different ways: (i) by studying the electroreduction of oxygen in anhydrous DMSO via a direct electron transfer mechanism without proton donors and (ii) by doing the same experiments in the presence of laccase substrates, which display in pure organic solvents both the properties of electron......The electroenzymatic reactions of Trametes hirsuta laccase in the pure organic solvent dimethyl sulfoxide (DMSO) have been investigated within the framework for potential use as a catalytic reaction scheme for oxygen reduction. The bioelectrochemical characteristics of laccase were investigated...... donors as well as the properties of weak acids. The results obtained with laccase in anhydrous DMSO were compared with those obtained previously in aqueous buffer. It was shown that in the absence of proton donors under oxygenated conditions, formation of superoxide anion radicals is prevented at bare...

  9. Effect of some organic solvents on oxidative phosphorylation in rat liver mitochondria

    DEFF Research Database (Denmark)

    Syed, Muzeeb; Skonberg, Christian; Hansen, Steen Honoré

    2013-01-01

    The effect of acetone, acetonitrile, dimethyl sulfoxide (DMSO), ethanol and methanol on oxidative phosphorylation (ATP synthesis) in rat liver mitochondria has been studied. All the organic solvents inhibited the oxidative phosphorylation in a concentration dependent manner, but with differences...... in potencies. Among the tested organic solvents, acetonitrile and acetone were more potent than ethanol, methanol, and DMSO. There was no significant difference in oxidative phosphorylation, compared to controls, when the concentrations of acetone was below 1% (v/v), of acetonitrile below 2% (v/v), of DMSO...... below 10% (v/v), of ethanol below 5% or of methanol below 2%, respectively. There was complete inhibition of oxidative phosphorylation at 50% (v/v) of acetone, acetonitrile and ethanol. But in the case of DMSO and methanol there were some residual activities observed at the 50% concentration level. DMSO...

  10. Ultrathin graphene-based membrane with precise molecular sieving and ultrafast solvent permeation

    Science.gov (United States)

    Yang, Q.; Su, Y.; Chi, C.; Cherian, C. T.; Huang, K.; Kravets, V. G.; Wang, F. C.; Zhang, J. C.; Pratt, A.; Grigorenko, A. N.; Guinea, F.; Geim, A. K.; Nair, R. R.

    2017-12-01

    Graphene oxide (GO) membranes continue to attract intense interest due to their unique molecular sieving properties combined with fast permeation. However, their use is limited to aqueous solutions because GO membranes appear impermeable to organic solvents, a phenomenon not yet fully understood. Here, we report efficient and fast filtration of organic solutions through GO laminates containing smooth two-dimensional (2D) capillaries made from large (10-20 μm) flakes. Without modification of sieving characteristics, these membranes can be made exceptionally thin, down to ~10 nm, which translates into fast water and organic solvent permeation. We attribute organic solvent permeation and sieving properties to randomly distributed pinholes interconnected by short graphene channels with a width of 1 nm. With increasing membrane thickness, organic solvent permeation rates decay exponentially but water continues to permeate quickly, in agreement with previous reports. The potential of ultrathin GO laminates for organic solvent nanofiltration is demonstrated by showing >99.9% rejection of small molecular weight organic dyes dissolved in methanol. Our work significantly expands possibilities for the use of GO membranes in purification and filtration technologies.

  11. SOLUTION THERMODYNAMICS OF TRICLOSAN AND TRICLOCARBAN IN SOME VOLATILE ORGANIC SOLVENTS

    OpenAIRE

    DELGADO, Daniel R.; R. HOLGUIN, Andres; MARTÍNEZ, Fleming

    2012-01-01

    Thermodynamic functions of Gibbs energy, enthalpy, and entropy for the solution processes of the antimicrobial drugs Triclosan and Triclocarban in five volatile organic solvents were calculated from solubility values at temperatures from 293.15 to 313.15 K. Triclosan and Triclocarban solubility was determined in acetone, acetonitrile (AcCN), ethyl acetate (AcOEt), methanol (MetOH), and cyclohexane (CH). The excess of Gibbs energy and the activity coefficients of the solutes were also calculat...

  12. Process for plutonium rextraction in aqueous solution from an organic solvent, especially for uranium plutonium partition

    International Nuclear Information System (INIS)

    Germain, M.; Gillet, B.; Pasquiou, J.Y.

    1989-01-01

    The organic solvent containing plutonium is contacted with an aqueous solution of a uranous salt, for instance uranous nitrate, and a hydroxylamine salt, for instance the nitrate. In these conditions uranous nitrate is a reducing agent of Pu III and hydroxylamine nitrate stabilizes Pu III and U IV in the aqueous phase. Performances are similar to these of the U IV-hydrazine nitrate without interference of hydrazine nitrate degradation products [fr

  13. Effect of reduced use of organic solvents on disability pension in painters.

    Science.gov (United States)

    Järvholm, Bengt; Burdorf, Alex

    2017-11-01

    To investigate whether the decreased use of paints based on organic solvents has caused a decreased risk for neuropsychiatric disorders in painters by studying their incidence in disability pensions. The incidence of disability pension in Swedish painters who had participated in health examinations between 1971 and 1993 was studied through linkage with Swedish registers of disability pension over 1971-2010 and compared with the incidence in other construction workers as woodworkers, concrete workers and platers. When phasing out began in the 1970s, about 40% of paints were based on organic solvents and it had decreased to 4% in 1990s. The analysis was adjusted for age, time period, body mass index and smoking. The painters (n=23 065) had an increased risk of disability pension due to neurological diagnosis (n=285, relative risk (RR) 1.92, 95% CI 1.67 to 2.20) and psychiatric diagnosis (n=632, RR=1.61, 95 % CI 1.42 to 1.82). For neurological disorders there was a time trend with a continuously decreasing risk from 1980 onwards, but there was no such trend for psychiatric disorders. High exposure to organic solvents increased the risk for disability pension in neurological disorders, and the risk decreased when the use of organic solvents decreased. The painters also had an increased risk of disability pension due to psychiatric disorders, but the causes have to be further investigated. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  14. Reduction of organic solvent emission by industrial use of electron-beam curable coatings

    International Nuclear Information System (INIS)

    Haering, E.

    1982-01-01

    Most industrial finishing processes operate by the use of liquid organic coating materials drying by solvent evaporation and subsequent chemical crosslinking reactions, in many cases also releasing cleavage products. These organic emissions contribute to air pollution and therefore many countries have issued restrictions in order to protect the environment. Complementary to other modern methods for reducing this problem, radiation chemistry enables an approach by radical chain polymerization which can be induced by exposure to electron radiation. This procedure is known as electron-beam curing of coatings or the EBC process. It utilizes well-developed accelerator equipment with voltages of 150 to 400kV at a minimum energy consumption. There is no necessity to use irradiation facilities based on the decay of radioisotopes. Free radical polymerization requires unsaturated resins as pain binders and polymerizable liquid compounds (monomers) as reactive diluents. Their crosslinking yields a high molecular network, the coating, without any emission of organic solvents or cleavage products. Moreover, the radiochemical formation of the paint film occurs extremely rapidly. The technical application of EBC coatings began by coating automotive plastic parts; a little later the finishing of wood products gained more industrial use as a non-polluting and energy-saving coating technology. Application methods in coating plastic foils in combination with vacuum metallizing and the production of decorative laminating papers for furniture followed. In 1981 new EBC pilot lines were installed for curing top coats on PVC foil and also for the coating of prefinished steel wheels for automobiles. In comparison with conventional solvent-based methods the industrial EBC process results in a nearly complete reduction of organic solvent emission avoiding air pollution and saving valuable petrochemical raw materials. This paper reviews the development of EBC during the last decade. (author)

  15. Real-time ESI-MS of enzymatic conversion: impact of organic solvents and multiplexing.

    Science.gov (United States)

    Scheerle, Romy K; Grassmann, Johanna; Letzel, Thomas

    2012-01-01

    Different enzymatic assays were characterized systematically by real-time electrospray ionization mass spectrometry (ESI-MS) in the presence of organic solvents as well as in multiplex approaches and in a combination of both. Typically, biological enzymatic reactions are studied in aqueous solutions, since most enzymes show their full activity solely in aqueous solutions. However, in recent years, the use of organic solvents in combination with enzymatic reactions has gained increasing interest due to biotechnological advantages in chemical synthesis, development of online coupled setups screening for enzyme regulatory compounds, advantages regarding mass spectrometric detection and others. In the current study, the influence of several common organic solvents (methanol, ethanol, isopropanol, acetone, acetonitrile) on enzymatic activity (hen egg white lysozyme, chitinase, α-chymotrypsin, elastase from human neutrophils and porcine pancreas, acetylcholinesterase) was tested. Moreover, multiplexing is a promising approach enabling fast and cost-efficient screening methods, e.g. for determination of inhibitors in complex mixtures or in the field of biomedical research. Although in multiplexed setups the enzymatic activity may be affected by the presence of other substrates and/or enzymes, the expected advantages possibly will predominate. To investigate those effects, we measured multiple enzymatic assays simultaneously. For all conducted measurements, the conversion rate of the substrate(s) was calculated, which reflects the enzymatic activity. The results provide an overview about the susceptibility of the selected enzymes towards diverse factors and a reference point for many applications in analytical chemistry and biotechnology.

  16. Purification and Characterization of Organic Solvent and Detergent Tolerant Lipase from Thermotolerant Bacillus sp. RN2

    Directory of Open Access Journals (Sweden)

    Tadahiko Kajiwara

    2010-09-01

    Full Text Available The aim of this study was to characterize the organic solvent and detergent tolerant properties of recombinant lipase isolated from thermotolerant Bacillus sp. RN2 (Lip-SBRN2. The isolation of the lipase-coding gene was achieved by the use of inverse and direct PCR. The complete DNA sequencing of the gene revealed that the lip-SBRN2 gene contains 576 nucleotides which corresponded to 192 deduced amino acids. The purified enzyme was homogeneous with the estimated molecular mass of 19 kDa as determined by SDS-PAGE and gel filtration. The Lip-SBRN2 was stable in a pH range of 9–11 and temperature range of 45–60 °C. The enzyme was a non metallo-monomeric protein and was active against pNP-caprylate (C8 and pNP-laurate (C12 and coconut oil. The Lip-SBRN2 exhibited a high level of activity in the presence of 108% benzene, 102.4% diethylether and 112% SDS. It is anticipated that the organic solvent and detergent tolerant enzyme secreted by Bacillus sp. RN2 will be applicable as catalysts for reaction in the presence of organic solvents and detergents.

  17. Understanding dissolution behavior of 193nm photoresists in organic solvent developers

    Science.gov (United States)

    Lee, Seung-Hyun; Park, Jong Keun; Cardolaccia, Thomas; Sun, Jibin; Andes, Cecily; O'Connell, Kathleen; Barclay, George G.

    2012-03-01

    Herein, we investigate the dissolution behavior of 193-nm chemically amplified resist in different organic solvents at a mechanistic level. We previously reported the effect of solvent developers on the negative tone development (NTD) process in both dry and immersion lithography, and demonstrated various resist performance parameters such as photospeed, critical dimension uniformity, and dissolution rate contrast are strongly affected by chemical nature of the organic developer. We further pursued the investigation by examining the dependence of resist dissolution behavior on their solubility properties using Hansen Solubility Parameter (HSP). The effects of monomer structure, and resist composition, and the effects of different developer chemistry on dissolution behaviors were evaluated by using laser interferometry and quartz crystal microbalance. We have found that dissolution behaviors of methacrylate based resists are significantly different in different organic solvent developers such as OSDTM-1000 Developer* and n-butyl acetate (nBA), affecting their resist performance. This study reveals that understanding the resist dissolution behavior helps to design robust NTD materials for higher resolution imaging.

  18. The salting-out of molibdoferrats(II from aqueous solutions by the organic solvents

    Directory of Open Access Journals (Sweden)

    Mykola V. Nikolenko

    2016-12-01

    Full Text Available The aim of this work was to develop a method for producing of molybdoferrate(II precipitates by salting-out them from aqueous solutions by means of organic solvents. Dependence of the composition of molybdoferrate(II precipitates on the pH of the reaction solutions was studied. Experiments on salting-out of molybdoferrate(II with various organic solvents were carried out. As a result it was found that the best reagent for the molybdoferrate(II salting-out is acetone. By its use, lowest quantity of the ammonium sulfate impurities was obtained. It is also of importance that by using of acetone the process of regeneration by distillation of the reaction solutions is characterized by the lowest energy consumption. A functional relationship between the solubility of molybdoferrates(II and dielectric constant of the medium was established. By increasing the dielectric constant of the solvent solubility of molybdoferrates(II rapidly increases. The linearized dependence ln(lnS–ln(1/e was proposed to predict the solubility of molybdoferrates(II in various aqueous-organic solutions.

  19. The secondary drying and the fate of organic solvents for spray dried dispersion drug product.

    Science.gov (United States)

    Hsieh, Daniel S; Yue, Hongfei; Nicholson, Sarah J; Roberts, Daniel; Schild, Richard; Gamble, John F; Lindrud, Mark

    2015-05-01

    To understand the mechanisms of secondary drying of spray-dried dispersion (SDD) drug product and establish a model to describe the fate of organic solvents in such a product. The experimental approach includes characterization of the SDD particles, drying studies of SDD using an integrated weighing balance and mass spectrometer, and the subsequent generation of the drying curve. The theoretical approach includes the establishment of a Fickian diffusion model. The kinetics of solvent removal during secondary drying from the lab scale to a bench scale follows Fickian diffusion model. Excellent agreement is obtained between the experimental data and the prediction from the modeling. The diffusion process is dependent upon temperature. The key to a successful scale up of the secondary drying is to control the drying temperature. The fate of primary solvents including methanol and acetone, and their potential impurity such as benzene can be described by the Fickian diffusion model. A mathematical relationship based upon the ratio of diffusion coefficient was established to predict the benzene concentration from the fate of the primary solvent during the secondary drying process.

  20. Effects of organic solvents on the enzyme activity of Trypanosoma cruzi glyceraldehyde-3-phosphate dehydrogenase in calorimetric assays

    DEFF Research Database (Denmark)

    Wiggers, Henrik; Cheleski, J; Zottis, A

    2007-01-01

    .0% for MeOH and up to 7.5% for DMSO. The results show that when GAPDH is assayed in the presence of DMSO (5%, v/v) using the ITC experiment, the enzyme exhibits approximately twofold higher activity than that of GAPDH with no cosolvent added. When MeOH (5%, v/v) is the cosolvent, the GAPDH activity......In drug discovery programs, dimethyl sulfoxide (DMSO) is a standard solvent widely used in biochemical assays. Despite the extensive use and study of enzymes in the presence of organic solvents, for some enzymes the effect of organic solvent is unknown. Macromolecular targets may be affected...... by the presence of different solvents in such a way that conformational changes perturb their active site structure accompanied by dramatic variations in activity when performing biochemical screenings. To address this issue, in this work we studied the effects of two organic solvents, DMSO and methanol (Me...

  1. Vapour permeation for the recovery of organic solvents from waste air streams: separation capacities and process optimization

    NARCIS (Netherlands)

    Leemann, M.; Leemann, M.; Eigenberger, G.; Strathmann, H.

    1996-01-01

    Vapour permeation is a potentially suitable technology for the recovery of organic solvents from waste air streams. New solvent stable capillary membrane modules that are currently emerging on the market provide large membrane areas for an acceptable price and enhance the competitiveness of this

  2. Nickel-Catalyzed Suzuki-Miyaura Cross-Coupling in a Green Alcohol Solvent for an Undergraduate Organic Chemistry Laboratory

    Science.gov (United States)

    Hie, Liana; Chang, Jonah J.; Garg, Neil K.

    2015-01-01

    A modern undergraduate organic chemistry laboratory experiment involving the Suzuki-Miyaura coupling is reported. Although Suzuki-Miyaura couplings typically employ palladium catalysts in environmentally harmful solvents, this experiment features the use of inexpensive nickel catalysis, in addition to a "green" alcohol solvent. The…

  3. Effect of organic solvents on dissolution process of mechano-chemically activated molybdenum by inorganic acid solutions

    International Nuclear Information System (INIS)

    Shevtsova, I.Ya.; Chernyak, A.S.; Khal'zov, A.A.

    1992-01-01

    The process of chemical dissolution of mechanochemically activated and nonactivated molybdenite by inorganic acid solutions in certain organic solvents of different nature was considered. It is shown that the highest extraction of molybdenum in solution is achieved in the presence of nitric acid. The dissociation constant of the acid used in the given organic solvent does not affect molybdenite solubility. When dissolving molybdenite by solutions of nitric acid in carbonic acids, alcohols and esters, the solubility of the concentrate depends on the length of hydrocarbon chain of the organic solvent and dispersion degree of mineral source material

  4. Chronic Organic Solvent Exposure Changes Visual Tracking in Men and Women

    Directory of Open Access Journals (Sweden)

    Ana R. de Oliveira

    2017-11-01

    Full Text Available Organic solvents can change CNS sensory and motor function. Eye-movement analyses can be important tools when investigating the neurotoxic changes that result from chronic organic solvent exposure. The current research measured the eye-movement patterns of men and women with and without histories of chronic organic solvent exposure. A total of 44 volunteers between 18 and 41 years old participated in this study; 22 were men (11 exposed and 11 controls, and 22 were women (11 exposed and 11 controls. Eye movement was evaluated using a 250-Hz High-Speed Video Eye Tracker Toolbox (Cambridge Research Systems via an image of a maze. Specific body indices of exposed and non-exposed men and women were measured with an Inbody 720 to determine whether the differences in eye-movement patterns were associated with body composition. The data were analyzed using IBM SPSS Statistics version 20.0.0. The results indicated that exposed adults showed significantly more fixations (t = 3.82; p = 0.001; r = 0.51 and longer fixations (t = 4.27; p = 0.001, r = 0.54 than their non-exposed counterparts. Comparisons within men (e.g., exposed and non-exposed showed significant differences in the number of fixations (t = 2.21; p = 0.04; r = 0.20 and duration of fixations (t = 3.29; p = 0.001; r = 0.35. The same was true for exposed vs. non-exposed women, who showed significant differences in the number of fixations (t = 3.10; p = 0.001; r = 0.32 and fixation durations (t = 2.76; p = 0.01; r = 0.28. However, the results did not show significant differences between exposed women and men in the number and duration of fixations. No correlations were found between eye-movement pattern and body composition measures (p > 0.05. These results suggest that chronic organic solvent exposure affects eye movements, regardless of sex and body composition, and that eye tracking contributes to the investigation of the visual information processing disorders acquired by workers exposed to

  5. Chronic Organic Solvent Exposure Changes Visual Tracking in Men and Women.

    Science.gov (United States)

    de Oliveira, Ana R; Campos Neto, Armindo de Arruda; Bezerra de Medeiros, Paloma C; de Andrade, Michael J O; Dos Santos, Natanael A

    2017-01-01

    Organic solvents can change CNS sensory and motor function. Eye-movement analyses can be important tools when investigating the neurotoxic changes that result from chronic organic solvent exposure. The current research measured the eye-movement patterns of men and women with and without histories of chronic organic solvent exposure. A total of 44 volunteers between 18 and 41 years old participated in this study; 22 were men (11 exposed and 11 controls), and 22 were women (11 exposed and 11 controls). Eye movement was evaluated using a 250-Hz High-Speed Video Eye Tracker Toolbox (Cambridge Research Systems) via an image of a maze. Specific body indices of exposed and non-exposed men and women were measured with an Inbody 720 to determine whether the differences in eye-movement patterns were associated with body composition. The data were analyzed using IBM SPSS Statistics version 20.0.0. The results indicated that exposed adults showed significantly more fixations ( t = 3.82; p = 0.001; r = 0.51) and longer fixations ( t = 4.27; p = 0.001, r = 0.54) than their non-exposed counterparts. Comparisons within men (e.g., exposed and non-exposed) showed significant differences in the number of fixations ( t = 2.21; p = 0.04; r = 0.20) and duration of fixations ( t = 3.29; p = 0.001; r = 0.35). The same was true for exposed vs. non-exposed women, who showed significant differences in the number of fixations ( t = 3.10; p = 0.001; r = 0.32) and fixation durations ( t = 2.76; p = 0.01; r = 0.28). However, the results did not show significant differences between exposed women and men in the number and duration of fixations. No correlations were found between eye-movement pattern and body composition measures ( p > 0.05). These results suggest that chronic organic solvent exposure affects eye movements, regardless of sex and body composition, and that eye tracking contributes to the investigation of the visual information processing disorders acquired by workers exposed to

  6. Impact of solvent extraction organics on adsorption and bioleaching of A. ferrooxidans and L. ferriphilum

    Science.gov (United States)

    Hualong, Yu; Xiaorong, Liu

    2017-04-01

    Copper solvent extraction entrained and dissoluted organics (SX organics) in the raffinate during SX operation can contaminated chalcopyrite ores and influence bioleaching efficiency by raffinate recycling. The adsorption and bioleaching of A. ferrooxidans and L. ferriphilum with contaminated ores were investigated. The results showed that, A. ferrooxidans and L. ferriphilum cells could adsorb quickly on minerals, the adsorption rate on contaminated ores were 83% and 60%, respectively, larger than on uncontaminated ores. However, in the bioleaching by the two kinds of acid bacterias, contaminated ores presented a lower bioleaching efficiency.

  7. Thermodynamics of solvent interaction with the metal-organic framework MOF-5.

    Science.gov (United States)

    Akimbekov, Zamirbek; Wu, Di; Brozek, Carl K; Dincă, Mircea; Navrotsky, Alexandra

    2016-01-14

    The inclusion of solvent in metal-organic framework (MOF) materials is a highly specific form of guest-host interaction. In this work, the energetics of solvent MOF-5 interactions has been investigated by solution calorimetry in 5 M sodium hydroxide (NaOH) at room temperature. Solution calorimetric measurement of enthalpy of formation (ΔH(f)) of Zn4O(C8H4O4)3·C3H7NO (MOF-5·DMF) and Zn4O(C8H4O4)3·0.60C5H11NO (MOF-5·0.60DEF) from the dense components zinc oxide (ZnO), 1,4-benzenedicarboxylic acid (H2BDC), N,N-dimethylformamide (DMF) and N,N-diethylformamide (DEF) gives values of 16.69 ± 1.21 and 45.90 ± 1.46 kJ (mol Zn4O)(-1), respectively. The enthalpies of interaction (ΔH(int)) for DMF and DEF with MOF-5 are -82.78 ± 4.84 kJ (mol DMF)(-1) and -89.28 ± 3.05 kJ (mol DEF)(-1), respectively. These exothermic interaction energies suggest that, at low guest loading, Lewis base solvents interact more strongly with electron accepting Zn4O clusters in the MOF than at high solvent loading. These data provide a quantitative thermodynamic basis to investigate transmetallation and solvent assisted linker exchange (SALE) methods and to synthesize new MOFs.

  8. Natural deep eutectic solvents as the major mobile phase components in high-performance liquid chromatography-searching for alternatives to organic solvents.

    Science.gov (United States)

    Sutton, Adam T; Fraige, Karina; Leme, Gabriel Mazzi; da Silva Bolzani, Vanderlan; Hilder, Emily F; Cavalheiro, Alberto J; Arrua, R Dario; Funari, Cristiano Soleo

    2018-06-01

    Over the past six decades, acetonitrile (ACN) has been the most employed organic modifier in reversed-phase high-performance liquid chromatography (RP-HPLC), followed by methanol (MeOH). However, from the growing environmental awareness that leads to the emergence of "green analytical chemistry," new research has emerged that includes finding replacements to problematic ACN because of its low sustainability. Deep eutectic solvents (DES) can be produced from an almost infinite possible combinations of compounds, while being a "greener" alternative to organic solvents in HPLC, especially those prepared from natural compounds called natural DES (NADES). In this work, the use of three NADES as the main organic component in RP-HPLC, rather than simply an additive, was explored and compared to the common organic solvents ACN and MeOH but additionally to the greener ethanol for separating two different mixtures of compounds, one demonstrating the elution of compounds with increasing hydrophobicity and the other comparing molecules of different functionality and molar mass. To utilize NADES as an organic modifier and overcome their high viscosity monolithic columns, temperatures at 50 °C and 5% ethanol in the mobile phase were used. NADES are shown to give chromatographic performances in between those observed for ACN and MeOH when eluotropic strength, resolution, and peak capacity were taken into consideration, while being less environmentally impactful as shown by the HPLC-Environmental Assessment Tool (HPLC-EAT) metric. With the development of proper technologies, DES could open a new class of mobile phases increasing the possibilities of new separation selectivities while reducing the environmental impact of HPLC analyses. Graphical abstract Natural deep eutectic solvents versus traditional solvents in HPLC.

  9. Transfers of Colloidal Silica from Water into Organic Solvents of Intermediate Polarities

    Science.gov (United States)

    Kasseh; Keh

    1998-01-15

    Dispersions of discrete metal-oxide submicroparticles in organic solvents of medium polarities are uneasy to generate and weakly documented. We address this topic along two general methods focusing on silica. Successive transfers of colloidal particles from water into n-propanol and then into 1,2-dichloroethane by azeotropic distillation yield a stable organosol. The particles are found to be propanol-coated by surface esterification to the extent of 0.40 nm2 per molecule. Alternatively, centrifugation-redispersion cycles make it possible to obtain stable suspensions of unaltered silica in methanol and acetonitrile starting from an aqueous silicasol. Particles are characterized by various methods including nitrogen adsorption, transmission electron microscopy, dynamic light scattering, and electrophoresis. The stabilities of these suspensions in various organic solvents are investigated with special concern for the role of residual water. Stabilization of silica in methanol is inconspicuously related to solvent permittivity and prominently dependent on the presence of adsorbed water. In contrast, the acetonitrile silicasol, which is unaffected by residual water, displays electrophoretic behavior compatible with electrostatic stabilization. Copyright 1998 Academic Press. Copyright 1998Academic Press

  10. Reversible brain damage following acute organic solvents' poisoning determined by magnetic resonance

    Directory of Open Access Journals (Sweden)

    Dujmović Irena

    2005-01-01

    Full Text Available Introduction. Acute exposure to the effects of volatile solvents is characterized by the abrupt onset of symptoms and signs of poisoning, and relatively fast recovery in the majority of cases. Case report. We report a 24-year-old patient with an acute, accidental poisoning with a mixture of volatile organic solvents (most probably toluene, styrene and xylene, which led to the development of upward gaze paresis, diplopia, hemiparesis, ataxic gate, and the late onset truncal ataxia episodes. After 6 weeks, he recovered completely, while his extensive brain MRI lesions in the caudate nuclei, laterobasal putaminal regions, bilateral anterior insular cortex, central midbrain tegmental area withdrew completely after 4 months. Conclusion. Acute toxic encephalopathy should be a part of the differential diagnosis in any patient with acute neurobehavioral and neurological deficit.

  11. Ionic Liquids Beyond Simple Solvents: Glimpses at the State of the Art in Organic Chemistry.

    Science.gov (United States)

    Kuchenbuch, Andrea; Giernoth, Ralf

    2015-12-01

    Within the last 25 years ionic liquids have written a tremendous success story, which is documented in a nearly uncountable amount of original research papers, reviews, and numerous applications in research and industry. These days, ionic liquids can be considered as a mature class of compounds for many different applications. Frequently, they are used as neoteric solvents for chemical tansformations, and the number of reviews on this field of research is huge. In this focused review, though, we are trying to evaluate the state of the art of ionic liquid chemistry beyond using them simply as solvents for chemical transformations. It is not meant to be a comprehensive overview on the topic; the choice of emphasis and examples rather refects the authors' personal view on the field. We are especially highlighting fields in which we believe the most fundamental developments within the next five years will take place: biomass processing, (chiral) ionic liquids from natural sources, biotransformations, and organic synthesis.

  12. Solvent polarity and nanoscale morphology in bulk heterojunction organic solar cells: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Ajith [Centre for Nano-Bio-Polymer Science and Technology, Department of Physics, St. Thomas College, Pala, Kerala 686574 (India); Research and Development Centre, Bharathiar University, Coimbatore, Tamilnadu 641046 (India); Elsa Tom, Anju; Ison, V. V., E-mail: isonvv@yahoo.in, E-mail: praveen@materials.iisc.ernet.in [Centre for Nano-Bio-Polymer Science and Technology, Department of Physics, St. Thomas College, Pala, Kerala 686574 (India); Rao, Arun D.; Varman, K. Arul; Ranjith, K.; Ramamurthy, Praveen C., E-mail: isonvv@yahoo.in, E-mail: praveen@materials.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science Bangalore, Karnataka 560012 (India); Vinayakan, R. [Department of Chemistry, SVR NSS College Vazhoor, Kerala 686505 (India)

    2014-03-14

    Organic bulk heterojunction solar cells were fabricated under identical experimental conditions, except by varying the solvent polarity used for spin coating the active layer components and their performance was evaluated systematically. Results showed that presence of nitrobenzene-chlorobenzene composition governs the morphology of active layer formed, which is due to the tuning of solvent polarity as well as the resulting solubility of the P3HT:PCBM blend. Trace amount of nitrobenzene favoured the formation of better organised P3HT domains, as evident from conductive AFM, tapping mode AFM and surface, and cross-sectional SEM analysis. The higher interfacial surface area thus generated produced cells with high efficiency. But, an increase in the nitrobenzene composition leads to a decrease in cell performance, which is due to the formation of an active layer with larger size polymer domain networks with poor charge separation possibility.

  13. Solvent polarity and nanoscale morphology in bulk heterojunction organic solar cells: A case study

    International Nuclear Information System (INIS)

    Thomas, Ajith; Elsa Tom, Anju; Ison, V. V.; Rao, Arun D.; Varman, K. Arul; Ranjith, K.; Ramamurthy, Praveen C.; Vinayakan, R.

    2014-01-01

    Organic bulk heterojunction solar cells were fabricated under identical experimental conditions, except by varying the solvent polarity used for spin coating the active layer components and their performance was evaluated systematically. Results showed that presence of nitrobenzene-chlorobenzene composition governs the morphology of active layer formed, which is due to the tuning of solvent polarity as well as the resulting solubility of the P3HT:PCBM blend. Trace amount of nitrobenzene favoured the formation of better organised P3HT domains, as evident from conductive AFM, tapping mode AFM and surface, and cross-sectional SEM analysis. The higher interfacial surface area thus generated produced cells with high efficiency. But, an increase in the nitrobenzene composition leads to a decrease in cell performance, which is due to the formation of an active layer with larger size polymer domain networks with poor charge separation possibility

  14. Comparison of the Behaviour of Polymers in Supercritical Fluids and Organic Solvents Via Small Angle Neutron Scattering

    International Nuclear Information System (INIS)

    Melnichenko, Y.B.; Kiran, E.; Heath, K.D.; Salaniwal, S.; Cochran, H.D.; Stamm, M.; Van Hook, W.A.; Wignall, G.D.

    1999-01-01

    Small-angle neutron scattering has been used to study the effect of temperature and pressure on the phase behavior of semidilute solutions of polymers dissolved in organic and supercritical solvents. Above the theta temperature (To), these systems exhibit a ''good solvent'' domain, where the molecules expand beyond the unperturbed dimensions in both organic solvents and in COZ. However, this transition can be made to occur at a critical ''theta pressure'' (PO) in CO2 and this represents a new concept in the physics of polymer-solvent systems. For T < To, and P < Po, the system enters the ''poor solvent'' domain where diverging concentration fluctuations prevent the chains from collapsing and allow them to maintain their unperturbed dimensions

  15. 40 CFR 63.5749 - How do I calculate the organic HAP content of aluminum wipedown solvents?

    Science.gov (United States)

    2010-07-01

    ... Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5749 How do I calculate... fraction of organic HAP in aluminum wipedown solvent j. m = number of different aluminum surface coatings...

  16. Part I: the effect of long-term exposure to organic solvents on memory: a cross sectional study.

    Science.gov (United States)

    Ratzon, N Z; Vakil, E; Derazne, E; Sculsky, M

    1998-01-01

    This study focuses on a wide range of different aspects of memory functions trying to ascertain a possible profile of memory changes, which take place following long-term exposure to organic solvents. The research design was cross-sectional. Study population included 31 industrial painters who were exposed at work to organic solvents and 31 unexposed workers. Workers after long-term exposure to organic solvents showed significant decline in memory as indicated in all three standard memory tests (i.e. Wechsler Memory Scale - Revised, Benton Revised Visual Retention Test, and Rey Auditory Verbal Learning Test). The results of Rey Auditory Verbal Learning Test showed a negative correlation with exposure index indicating that the more intensive and longer the time of exposure was, the more impaired is the verbal memory. It was also found that the affect of age on memory was stronger among workers after long-term exposure to organic solvents compared to the unexposed workers.

  17. Comparative responses of river biofilms at the community level to common organic solvent and herbicide exposure.

    Science.gov (United States)

    Paule, A; Roubeix, V; Swerhone, G D W; Roy, J; Lauga, B; Duran, R; Delmas, F; Paul, E; Rols, J L; Lawrence, J R

    2016-03-01

    Residual pesticides applied to crops migrate from agricultural lands to surface and ground waters. River biofilms are the first aquatic non-target organisms which interact with pesticides. Therefore, ecotoxicological experiments were performed at laboratory scale under controlled conditions to investigate the community-level responses of river biofilms to a chloroacetanilide herbicide (alachlor) and organic solvent (methanol) exposure through the development referenced to control. Triplicate rotating annular bioreactors, inoculated with river water, were used to cultivate river biofilms under the influence of 1 and 10 μg L(-1) of alachlor and 25 mg L(-1) of methanol. For this purpose, functional (thymidine incorporation and carbon utilization spectra) and structural responses of microbial communities were assessed after 5 weeks of development. Structural aspects included biomass (chlorophyll a, confocal laser scanning microscopy) and composition (fluor-conjugated lectin binding, molecular fingerprinting, and diatom species composition). The addition of alachlor resulted in a significant reduction of bacterial biomass at 1 μg L(-1), whereas at 10 μg L(-1), it induced a significant reduction of exopolymer lectin binding, algal, bacterial, and cyanobacterial biomass. However, there were no changes in biofilm thickness or thymidine incorporation. No significant difference between the bacterial community structures of control and alachlor-treated biofilms was revealed by terminal restriction fragment length polymorphism (T-RFLP) analyses. However, the methanol-treated bacterial communities appeared different from control and alachlor-treated communities. Moreover, methanol treatment resulted in an increase of bacterial biomass and thymidine incorporation as well. Changes in dominant lectin binding suggested changes in the exopolymeric substances and community composition. Chlorophyll a and cyanobacterial biomass were also altered by methanol. This study suggested

  18. Exposure to organic solvents used in dry cleaning reduces low and high level visual function.

    Directory of Open Access Journals (Sweden)

    Ingrid Astrid Jiménez Barbosa

    Full Text Available To investigate whether exposure to occupational levels of organic solvents in the dry cleaning industry is associated with neurotoxic symptoms and visual deficits in the perception of basic visual features such as luminance contrast and colour, higher level processing of global motion and form (Experiment 1, and cognitive function as measured in a visual search task (Experiment 2.The Q16 neurotoxic questionnaire, a commonly used measure of neurotoxicity (by the World Health Organization, was administered to assess the neurotoxic status of a group of 33 dry cleaners exposed to occupational levels of organic solvents (OS and 35 age-matched non dry-cleaners who had never worked in the dry cleaning industry. In Experiment 1, to assess visual function, contrast sensitivity, colour/hue discrimination (Munsell Hue 100 test, global motion and form thresholds were assessed using computerised psychophysical tests. Sensitivity to global motion or form structure was quantified by varying the pattern coherence of global dot motion (GDM and Glass pattern (oriented dot pairs respectively (i.e., the percentage of dots/dot pairs that contribute to the perception of global structure. In Experiment 2, a letter visual-search task was used to measure reaction times (as a function of the number of elements: 4, 8, 16, 32, 64 and 100 in both parallel and serial search conditions.Dry cleaners exposed to organic solvents had significantly higher scores on the Q16 compared to non dry-cleaners indicating that dry cleaners experienced more neurotoxic symptoms on average. The contrast sensitivity function for dry cleaners was significantly lower at all spatial frequencies relative to non dry-cleaners, which is consistent with previous studies. Poorer colour discrimination performance was also noted in dry cleaners than non dry-cleaners, particularly along the blue/yellow axis. In a new finding, we report that global form and motion thresholds for dry cleaners were also

  19. Solubility and solution thermodynamics of 2-methyl-6-nitroaniline in ten organic solvents at elevated temperatures

    International Nuclear Information System (INIS)

    Cong, Yang; Wang, Jian; Du, Cunbin; Han, Shuo; Zhao, Hongkun

    2016-01-01

    Highlights: • Solubility of 2-methyl-6-nitroaniline in ten solvents were determined. • The solubility were correlated with four thermodynamic models. • Standard dissolution enthalpy and excess enthalpy of the solutions were computed. - Abstract: Knowledge of solubility for 2-methyl-6-nitroaniline in different solvents is essential for its purification and further theoretical studies. In this paper, the solid-liquid equilibrium for 2-methyl-6-nitroaniline in ten pure organic solvents (methanol, ethanol, n-propanol, isopropanol, toluene, ethyl acetate, acetonitrile, acetone, cyclohexane and 1,4-dioxane) was established using the isothermal saturation method at temperatures T = (278.15–313.15) K under pressure of 101.2 kPa, and the solubility of 2-methyl-6-nitroaniline in these solvents were determined by a high-performance liquid chromatography (HPLC). In general, the mole fraction solubility followed the following order from high to low in different solvents: 1,4-dioxane (0.1799–0.3390) > acetone (0.1128–0.3010) > ethyl acetate (0.08414–0.2654) > acetonitrile (0.04179–0.2027) > toluene (0.02367–0.1104) > n-propanol (0.01080–0.04514) > ethanol (0.01020–0.04202) > isopropanol (0.008595–0.03763) > methanol (0.007391–0.03198) > cyclohexane (0.001027–0.005617). The modified Apelblat equation, λh equation, Wilson model and NRTL model were employed to correlate the measured solubility data of 2-methyl-6-nitroaniline in the selected solvents. Results indicated that the largest values of RAD and RMSD acquired by the four models were less than 0.76% and 9.13 × 10"−"4, respectively. The modified Apelblat equation provided better results than the other three models. Furthermore, the standard dissolution enthalpy and excess enthalpy of the solutions were computed from the solubility values. The standard dissolution enthalpies vary within the range from (14.88 to 45.57) kJ·mol"−"1 and are all positive, the dissolution process of 2-methyl-6

  20. Mycobacterial Response to Organic Solvents and Possible Implications on Cross-Resistance With Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Cátia Pacífico

    2018-05-01

    Full Text Available Mycobacterium vaccae, a bacterium found in soil, has been receiving attention as adjuvant to antituberculosis treatment, vaccines and immunotherapies and even as antidepressant. This bacterium is also able to degrade several pollutants, including aromatic compounds. The increasing presence of organic solvents in the environment may lead to M. vaccae adapted populations. A possible relationship between solvent tolerance and decreased susceptibility to other types of chemicals, including antibiotics, may pose a problem during opportunistic infections. The present study thus aimed at assessing if solvent adapted cells presented higher tolerance to antibiotics and efflux pump inhibitors (EPIs. M. vaccae cells were able to thrive and grow in the presence of up 20% (v/v glycerol, 5% (v/v ethanol, 1% (v/v methyl tert-butyl ether (MTBE and 0.1% (v/v toluene. During adaptation to increasing concentration of ethanol and MTBE, the cells changed their fatty acid profile, zeta potential and morphology. Adapted cells acquired an improved tolerance toward the EPIs thioridazine and omeprazole, but became more susceptible to the antibiotics levofloxacin and teicoplanin when compared with non-adapted cells.

  1. Photo-dynamics of roseoflavin and riboflavin in aqueous and organic solvents

    International Nuclear Information System (INIS)

    Zirak, P.; Penzkofer, A.; Mathes, T.; Hegemann, P.

    2009-01-01

    Roseoflavin (8-dimethylamino-8-demethyl-D-riboflavin) and riboflavin in aqueous and organic solvents are studied by optical absorption spectroscopy, fluorescence spectroscopy, and fluorescence decay kinetics. Solvent polarity dependent absorption shifts are observed. The fluorescence quantum yields are solvent dependent. For roseoflavin the fluorescence decay shows a bi-exponential dependence (ps to sub-ps time constant, and 100 ps to a few ns time constant). The roseoflavin photo-dynamics is explained in terms of fast intra-molecular charge transfer (diabatic electron transfer) from the dimethylamino electron donor group to the pteridin carbonyl electron acceptor followed by intra-molecular charge recombination. The fast fluorescence component is due to direct locally-excited-state emission, and the slow fluorescence component is due to delayed locally-excited-state emission and charge transfer state emission. The fluorescence decay of riboflavin is mono-exponential. The S 1 -state potential energy surface is determined by vibronic relaxation and solvation dynamics due to excited-state dipole moment changes (adiabatic optical electron transfer).

  2. Photo-dynamics of roseoflavin and riboflavin in aqueous and organic solvents

    Science.gov (United States)

    Zirak, P.; Penzkofer, A.; Mathes, T.; Hegemann, P.

    2009-03-01

    Roseoflavin (8-dimethylamino-8-demethyl- D-riboflavin) and riboflavin in aqueous and organic solvents are studied by optical absorption spectroscopy, fluorescence spectroscopy, and fluorescence decay kinetics. Solvent polarity dependent absorption shifts are observed. The fluorescence quantum yields are solvent dependent. For roseoflavin the fluorescence decay shows a bi-exponential dependence (ps to sub-ps time constant, and 100 ps to a few ns time constant). The roseoflavin photo-dynamics is explained in terms of fast intra-molecular charge transfer (diabatic electron transfer) from the dimethylamino electron donor group to the pteridin carbonyl electron acceptor followed by intra-molecular charge recombination. The fast fluorescence component is due to direct locally-excited-state emission, and the slow fluorescence component is due to delayed locally-excited-state emission and charge transfer state emission. The fluorescence decay of riboflavin is mono-exponential. The S 1-state potential energy surface is determined by vibronic relaxation and solvation dynamics due to excited-state dipole moment changes (adiabatic optical electron transfer).

  3. Photo-dynamics of roseoflavin and riboflavin in aqueous and organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Zirak, P. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany); Penzkofer, A., E-mail: alfons.penzkofer@physik.uni-regensburg.de [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany); Mathes, T.; Hegemann, P. [Institut fuer Biologie/Experimentelle Biophysik, Humboldt Universitaet zu Berlin, Invalidenstrasse 42, D-10115 Berlin (Germany)

    2009-03-30

    Roseoflavin (8-dimethylamino-8-demethyl-D-riboflavin) and riboflavin in aqueous and organic solvents are studied by optical absorption spectroscopy, fluorescence spectroscopy, and fluorescence decay kinetics. Solvent polarity dependent absorption shifts are observed. The fluorescence quantum yields are solvent dependent. For roseoflavin the fluorescence decay shows a bi-exponential dependence (ps to sub-ps time constant, and 100 ps to a few ns time constant). The roseoflavin photo-dynamics is explained in terms of fast intra-molecular charge transfer (diabatic electron transfer) from the dimethylamino electron donor group to the pteridin carbonyl electron acceptor followed by intra-molecular charge recombination. The fast fluorescence component is due to direct locally-excited-state emission, and the slow fluorescence component is due to delayed locally-excited-state emission and charge transfer state emission. The fluorescence decay of riboflavin is mono-exponential. The S{sub 1}-state potential energy surface is determined by vibronic relaxation and solvation dynamics due to excited-state dipole moment changes (adiabatic optical electron transfer).

  4. Measuring the relative hydrogen-bonding strengths of alcohols in aprotic organic solvents.

    Science.gov (United States)

    Tessensohn, Malcolm E; Lee, Melvyn; Hirao, Hajime; Webster, Richard D

    2015-01-12

    Voltammetric experiments with 9,10-anthraquinone and 1,4-benzoquinone performed under controlled moisture conditions indicate that the hydrogen-bond strengths of alcohols in aprotic organic solvents can be differentiated by the electrochemical parameter ΔEp (red) =|Ep (red(1)) -Ep (red(2)) |, which is the potential separation between the two one-electron reduction processes. This electrochemical parameter is inversely related to the strength of the interactions and can be used to differentiate between primary, secondary, tertiary alcohols, and even diols, as it is sensitive to both their steric and electronic properties. The results are highly reproducible across two solvents with substantially different hydrogen-bonding properties (CH3 CN and CH2 Cl2 ) and are supported by density functional theory calculations. This indicates that the numerous solvent-alcohol interactions are less significant than the quinone-alcohol hydrogen-bonding interactions. The utility of ΔEp (red) was illustrated by comparisons between 1) 3,3,3-trifluoro-n-propanol and 1,3-difluoroisopropanol and 2) ethylene glycol and 2,2,2-trifluoroethanol. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Radiation induced polymerization of MMA in imidazolium ionic liquids and their mixed solutions with organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Qi Mingying [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, P.O. Box 800-204, Shanghai 201800 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu Guozhong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, P.O. Box 800-204, Shanghai 201800 (China)], E-mail: wuguozhong@sinap.ac.cn; Sha Maolin; Liu Yusheng [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, P.O. Box 800-204, Shanghai 201800 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China)

    2008-10-15

    Considerably higher molecular weight (M{sub w}) and multi-modal molecular weight distribution (MWD) of poly(methyl methacrylate) (PMMA) were observed in neat ionic liquids ([bmim][PF{sub 6}] and [bmim][BF{sub 4}]), as well as their mixed solutions with organic solvents, probably due to the high viscosity and inhomogeneity of ionic liquids. FTIR spectra for PMMA showed that a slight amount of ionic liquid remained in the resulting polymer, and DSC measurement indicated the increase of glass transition point of PMMA with increasing of ionic liquid fraction in mixed solutions.

  6. Application of germination inhibitors in organic solvents to conifer seeds. Information report No. 0-X-371

    Energy Technology Data Exchange (ETDEWEB)

    Groot, A.

    1985-12-31

    Study to determine whether the germination inhibitors abscisic acid and coumarin could be applied to black spruce and jack pine seed with organic solvents to delay germination. If successful, the treatment would delay field germination of seeds sown in mid to late summer until the following spring, thus reducing the risk of immature plants being affected by late fall frosts. Results were expressed in germination value, peak day, and germination capacity on the basis of a 28-day germination period. Effects of treatment on the variables were examined by means of one-way or two-way analysis of variance with completely randomized designs.

  7. In-Vitro Characterization and Oral Bioavailability of Organic Solvent-free Solid Dispersions Containing Telmisartan

    DEFF Research Database (Denmark)

    Cao, Yue; Shi, Li-Li; Cao, Qing-Ri

    2016-01-01

    Poorly water-soluble drugs often suffer from limited or irreproducible clinical response due to their low solubility and dissolution rate. In this study, organic solvent-free solid dispersions (OSF-SDs) containing telmisartan (TEL) were prepared using polyvinylpyrrolidone K30 (PVP K30....... The results from DSC, XRD showed that TEL was molecularly dispersed in the OSF-SDs as an amorphous form. The FT-IR results suggested that intermolecular hydrogen bonding had formed between TEL and its carriers. The OSF-SDs exhibited significantly higher AUC0-24 h and Cmax, but similar Tmax as compared...

  8. SYNTHESIS AND CHARACTERIZATION OF CdSe COLLOIDAL QUANTUM DOTS IN ORGANIC SOLVENT

    Directory of Open Access Journals (Sweden)

    Ion Geru

    2014-06-01

    Full Text Available In this paper we present experimental results on preparation and characterization of colloidal CdSe quantum dots in organic solvent. CdSe QDs were synthesized following a modified literature method. CdSe QDs were isolated by adding acetone to the cooled solution followed by centrifugation. CdSe QDs have been characterized by UV-Vis absorption and photoluminescent (PL spectroscopy. The average CdSe particles size estimated from the UV-Vis absorption spectra was found to be in the range 2.28-2.92 nm which is in good agreement with PL measurements.

  9. The effect of organic water-miscible solvents on the extraction of uranium by TOA

    International Nuclear Information System (INIS)

    Shi Xiukun; Shen Xinghai; Pen Qixiu; Gao Hongchen

    1989-01-01

    The effect of organic water-miscible solvents, such as methanol, ethanol, acetone, dioxane, glycol, dimethylsulfoxide (DMSO), dimethylformamide (DMF), tetrahydrofurance (THF) in aqueous phase on the extraction of uranyl sulphate by tri-n-octylamine (TOA) has been investigated. All data obtained showed that the addition of alcohols, ketones etc. into aqueous phase brings about an increase of distribution ratio of uranium, whereas the addition of DMSO, DMF etc. brings about a decrease of distribution ratio of uranium. In the present study, the regularity and mechanism of extraction with TOA are further studied and discussed from the measurements of some physical properties, such as dielectric constant, interface tension etc

  10. Analysis of organic solvents and liquid mixtures using a fiber-tip evaporation sensor

    Science.gov (United States)

    Preter, Eyal; Donlagic, Denis; Artel, Vlada; Katims, Rachel A.; Sukenik, Chaim N.; Zadok, Avi

    2014-05-01

    The instantaneous size and rate of evaporation of pendant liquid droplets placed on the cleaved facet of a standard fiber are reconstructed based on reflected optical power. Using the evaporation dynamics, the relative contents of ethanol in ethanol-water binary mixtures are assessed with 1% precision and different blends of methanol in gasoline are properly recognized. The latter application, in particular, is significant for the use of alternative fuels in the automotive sector. Also, ten organic solvents are identified based on their evaporation from a fiber facet coated with a hydrophobic, selfassembled monolayer.

  11. Study of N-cinnamoylphenylhydroxylaminate solubility in water and organic solvents

    International Nuclear Information System (INIS)

    Pilipenko, A.T.; Shpak, Eh.A.; Samchuk, A.I.

    1975-01-01

    The composition of complexes of N-cinnamoylphenylhydroxylamine with copper, cadmium, lead, indium, iron, gallium, titanium, zirconium, hafnium, niobium, tantalum, tungsten, molybdenum and vanadium was determined. The solubility products of the N-cinnamoylphenylhydroxylaminates of copper, cadmium, indium, gallium and iron were determined by the method of measuring the solubility of precipitates in acid. The solubility of N-cinnamoylphenylhydroxalaminates of cadmium, indium, iron, titanium, zirconium, hafnium, niobium, tantalum, vanadium, molybdenum and tungsten in organic solvents was studied. Two-phase constants for the stability of the complexes were calculated. (author)

  12. Ion chromatographic determination of Di-n-butyl phosphate in degraded organic solvent

    International Nuclear Information System (INIS)

    Velavendan, P.; Pandey, N.K.; Kamachi Mudali, U.; Natarajan, R.

    2011-01-01

    In the present work a method for the determination of Di-n-butyl phosphate in organic streams using Ion Chromatography technique is developed and described here. The method involves the separation of Di-n-butyl phosphate (DBP) from 30% TBP-NPH (Tri-n-butylphosphate diluted in Normal Paraffin Hydrocarbon) and uranium/nitric acid matrix by an extraction of DBP in alkaline medium and subsequent ion-exchange separation in ion chromatography column followed by suppressed conductivity detection. Direct determination of DBP in lean/loaded organic solvent will lead to in accurate determination of DBP due to organic interference. DBP is quantified to lower limit of 1 ppm with 3% RSD. The results obtained with ion chromatographic technique are compared with those obtained by standard gas chromatographic technique. The developed method is much faster and total analysis can be completed within two hours. (author)

  13. 40 CFR Table 6 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in the following... type Average organic HAP mass fraction Typical organic HAP, percent by mass Aliphatic b 0.03 1% xylene...

  14. Low Operational Stability of Enzymes in Dry Organic Solvents: Changes in the Active Site Might Affect Catalysis

    Directory of Open Access Journals (Sweden)

    Gabriel Barletta

    2012-02-01

    Full Text Available The potential of enzyme catalysis in organic solvents for synthetic applications has been overshadowed by the fact that their catalytic properties are affected by organic solvents. In addition, it has recently been shown that an enzyme’s initial activity diminishes considerably after prolonged exposure to organic media. Studies geared towards understanding this last drawback have yielded unclear results. In the present work we decided to use electron paramagnetic resonance spectroscopy (EPR to study the motion of an active site spin label (a nitroxide free radical during 96 h of exposure of the serine protease subtilisin Carlsberg to four different organic solvents. Our EPR data shows a typical two component spectra that was quantified by the ratio of the anisotropic and isotropic signals. The isotropic component, associated with a mobile nitroxide free radical, increases during prolonged exposure to all solvents used in the study. The maximum increase (of 43% was observed in 1,4-dioxane. Based on these and previous studies we suggest that prolonged exposure of the enzyme to these solvents provokes a cascade of events that could induce substrates to adopt different binding conformations. This is the first EPR study of the motion of an active-site spin label during prolonged exposure of an enzyme to organic solvents ever reported.

  15. Preferential solvation and solvation shell composition of free base and protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin in aqueous organic mixed solvents

    Science.gov (United States)

    Farajtabar, Ali; Jaberi, Fatemeh; Gharib, Farrokh

    2011-12-01

    The solvatochromic properties of the free base and the protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) were studied in pure water, methanol, ethanol (protic solvents), dimethylsulfoxide, DMSO, (non-protic solvent), and their corresponding aqueous-organic binary mixed solvents. The correlation of the empirical solvent polarity scale ( ET) values of TPPS with composition of the solvents was analyzed by the solvent exchange model of Bosch and Roses to clarify the preferential solvation of the probe dyes in the binary mixed solvents. The solvation shell composition and the synergistic effects in preferential solvation of the solute dyes were investigated in terms of both solvent-solvent and solute-solvent interactions and also, the local mole fraction of each solvent composition was calculated in cybotactic region of the probe. The effective mole fraction variation may provide significant physico-chemical insights in the microscopic and molecular level of interactions between TPPS species and the solvent components and therefore, can be used to interpret the solvent effect on kinetics and thermodynamics of TPPS. The obtained results from the preferential solvation and solvent-solvent interactions have been successfully applied to explain the variation of equilibrium behavior of protonation of TPPS occurring in aqueous organic mixed solvents of methanol, ethanol and DMSO.

  16. Evaluation of the Process of Solvent Vapor Annealing on Organic Thin Films

    KAUST Repository

    Ren, Yi

    2011-07-01

    Solvent vapor annealing has recently emerged as an intriguing, room-temperature, and highly versatile alternative to thermal annealing. The chemically selective interaction between solvents and organic semiconductors opens new opportunities to selectively anneal certain components of the device, while leaving others intact. On the downside, these interactions are complex and rather unpredictable, requiring further investigation. We propose a novel methodology to investigate solvent-film interactions, based on use of an in situ quartz crystal microbalance with dissipation (QCM-D) capability and in situ grazing incidence wide angle X-ray scattering (GIWAXS). These methods make it possible to investigate both qualitatively and quantitatively the solvent vapor uptake, the resulting softening and changes (reversible and/or irreversible) in crystallinity. Using this strategy, we have investigated the solvent vapor annealing of traditional donor and acceptor materials, namely poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-Phenyl-C61-butyric acid methyl ester (PCBM). We find these materials retain their rigid structure during toluene vapor annealing and do not dewet. We also investigated the toluene vapor annealing of several newly proposed acceptor molecules (pentacene-based) modified with various silyl groups and electron withdrawing groups to tune the packing structure of the acceptor domains and energy levels at the donor-acceptor interface. We found a dramatic effect of the electron-withdrawing group on vapor uptake and whether the film remains rigid, softens, or dissolves completely. In the case of trifluoromethyl electron-withdrawing group, we found the film dissolves, resulting in complete and irreversible loss of long range order. By contrast, the cyano group prevented loss of long range order, instead promoting crystallization in some cases. The silyl groups had a secondary effect in comparison to these. In the last part of the thesis, we investigated the

  17. The effect of organic solvents on one-bottle adhesives' bond strength to enamel and dentin.

    Science.gov (United States)

    Reis, André Figueiredo; Oliveira, Marcelo Tavares; Giannini, Marcelo; De Goes, Mário Fernando; Rueggeberg, Frederick A

    2003-01-01

    This study evaluated the microtensile bond strength (pTBS) of ethanol/water- and acetone-based, one-bottle adhesive systems to enamel (E) and dentin (D) in the presence (P) or absence (A) of their respective solvents. Thirty-two freshly extracted third molars were flattened with 600-grit SiC paper and restored with Single Bond (SB) or Prime&Bond 2.1 (PB) according to the manufacturers' instructions and after full solvent elimination. The molars were divided into eight test groups (n = 4): G1-SB-E-P, G2-SB-E-A, G3-PBE-P, G4-PB-E-A, G5-SB-D-P, G6-SB-D-A, G7-PB-D-P and G8-PB-D-A. After applying the adhesive resins, composite crowns of approximately 8 mm were built up with TPH Spectrum composite. After 24-hour water storage, the specimens were serially sectioned bucco-lingually to obtain 0.8 mm slabs that were trimmed to an hourglass shape, approximately 0.8 mm2 at the bonded interface. The specimens were tested in tension using a universal testing machine (0.5 mm/minute). The results were statistically analyzed by ANOVA and Tukey test. The frequency of fracture mode was compared using the Kruskal-Wallis test. There were no statistically significant differences in mean bond strength among the groups restored with or without solvent for enamel. However, the results were significantly different for the dentin groups (MPa): G5-26.2 +/- 8.6a; G7-23.6 +/- 11.3ab; G6-12.8 +/- 2.1bc; G8-6.2 +/- 3.1c. SEM examination indicated that the dentin group failure modes were significantly different from the enamel groups. The results suggest that the presence of organic solvents does not influence microTBS to enamel. However, microTBS to dentin was significantly affected by the absence of solvents in the adhesive system.

  18. 40 CFR Table 3 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Metal Furniture Pt. 63, Subpt. RRRR, Table 3 Table 3 to Subpart RRRR of Part 63—Default Organic HAP Mass... blend CAS. No. Average organic HAP mass fraction Typical organic HAP, percent by mass 1. Toluene 108-88...

  19. Enhanced Enzymatic Synthesis of a Cephalosporin, Cefadroclor, in the Presence of Organic Co-solvents.

    Science.gov (United States)

    Liu, Kun; Li, Sha; Pang, Xiao; Xu, Zheng; Li, Dengchao; Xu, Hong

    2017-05-01

    In this study, we investigated the enzymatic synthesis of a semi-synthetic cephalosporin, cefadroclor, from 7-aminodesacetoxymethyl-3-chlorocephalosporanic acid (7-ACCA) and p-OH-phenylglycine methyl ester (D-HPGM) using immobilized penicillin G acylase (IPA) in organic co-solvents. Ethylene glycol (EG) was employed as a component of the reaction mixture to improve the yield of cefadroclor. EG was found to increase the yield of cefadroclor by 15-45%. An investigation of altered reaction parameters including type and concentration of organic solvents, pH of reaction media, reaction temperature, molar ratio of substrates, enzyme loading, and IPA recycling was carried out in the buffer mixture. The best result was a 76.5% conversion of 7-ACCA, which was obtained from the reaction containing 20% EG (v/v), D-HPGM to 7-ACCA molar ratio of 4:1 and pH 6.2, catalyzed by 16 IU mL -1 IPA at 20 °C for 10 h. Under the optimum conditions, no significant loss of IPA activity was found after seven repeated reaction cycles. In addition, cefadroclor exhibited strong inhibitory activity against yeast, Bacillus subtilis NX-2, and Escherichia coli and weaker activity against Staphylococcus aureus and Pseudomonas aeruginosa. Cefadroclor is a potential antibiotic with activity against common pathogenic microorganisms.

  20. Removal of polycyclic aromatic hydrocarbons from organic solvents by ashes wastes

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Gregorio, M.R.; Garcia-Falcon, M.S.; Martinez-Carballo, E. [Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, E32004 Ourense (Spain); Simal-Gandara, J., E-mail: jsimal@uvigo.es [Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, E32004 Ourense (Spain)

    2010-06-15

    Polycyclic aromatic hydrocarbons (PAHs) can be formed during the refinery processes of crude petroleum. Their removal is of great importance. The same happens with other organic solvents used for the extraction of PAHs (hexane, acetonitrile...), which can be polluted with PAHs. Kinetic and equilibrium batch sorption tests were used to investigate the effect of wood ashes wastes as compared to activated carbon on the sorption of three representative PAHs from n-hexane and acetonitrile. Mussel shell ashes were discarded for batch sorption experiments because they were the only ashes containing PAHs. The equilibrium time was reached at 16 h. Physical sorption caused by the aromatic nature of the compounds was the main mechanism that governed the PAHs removal process. Our investigation revealed that wood ashes obtained at lower temperature (300 deg. C) did not show any PAHs sorption, while ashes obtained at higher temperature (>500 deg. C) have adsorbent sites readily available for the PAH molecules. An increase in the molecular weight of PAHs has a strong effect on sorption wood ashes wastes. As low the wood ashes particle size as high the sorption of PAHs, as a result of differences in adsorbent sites. The performance of wood ash wastes vs. activated carbon to remove 10 PAHs from organic solvents is competitive in price, and a good way for waste disposal.

  1. Purification and Characterization of Haloalkaline, Organic Solvent Stable Xylanase from Newly Isolated Halophilic Bacterium-OKH

    Science.gov (United States)

    Sanghvi, Gaurav; Jivrajani, Mehul; Patel, Nirav; Jivrajani, Heta; Bhaskara, Govinal Badiger; Patel, Shivani

    2014-01-01

    A novel, alkali-tolerant halophilic bacterium-OKH with an ability to produce extracellular halophilic, alkali-tolerant, organic solvent stable, and moderately thermostable xylanase was isolated from salt salterns of Mithapur region, Gujarat, India. Identification of the bacterium was done based upon biochemical tests and 16S rRNA sequence. Maximum xylanase production was achieved at pH 9.0 and 37°C temperature in the medium containing 15% NaCl and 1% (w/v) corn cobs. Sugarcane bagasse and wheat straw also induce xylanase production when used as carbon source. The enzyme was active over a range of 0–25% sodium chloride examined in culture broth. The optimum xylanase activity was observed at 5% sodium chloride. Xylanase was purified with 25.81%-fold purification and 17.1% yield. Kinetic properties such as Km and Vmax were 4.2 mg/mL and 0.31 μmol/min/mL, respectively. The enzyme was stable at pH 6.0 and 50°C with 60% activity after 8 hours of incubation. Enzyme activity was enhanced by Ca2+, Mn2+, and Mg2+ but strongly inhibited by heavy metals such as Hg2+, Fe3+, Ni2+, and Zn2+. Xylanase was found to be stable in organic solvents like glutaraldehyde and isopropanol. The purified enzyme hydrolysed lignocellulosic substrates. Xylanase, purified from the halophilic bacterium-OKH, has potential biotechnological applications. PMID:27350996

  2. Removal of endotoxins from bacteriophage preparations by extraction with organic solvents.

    Directory of Open Access Journals (Sweden)

    Bożena Szermer-Olearnik

    Full Text Available Lipopolysaccharide (LPS, endotoxin, pyrogen constitutes a very troubling contaminant of crude phage lysates produced in Gram-negative bacteria. Toxicity of LPS depends on the strong innate immunity response including the cytokines. Therefore, its removal is important for bacteriophage applications. In this paper, we present a procedure for extractive removal of endotoxin from bacteriophage preparations with water immiscible solvents (1-octanol or 1-butanol. During extraction most of the phage lytic activity is retained in the aqueous phase, while endotoxin accumulates in the organic solvent. The levels of endotoxin (expressed as endotoxin units, EU in the aqueous bacteriophage-containing fraction determined by limulus amebocyte lysate or EndoLISA assay were exceptionally low. While the initial endotoxin levels in the crude phage lysates ranged between 10(3 and 10(5 EU/ml the average level after organic extraction remaining in the aqueous fraction was 5.3 EU/ml. These values when related to phage titers decreased from 10(3-10(5 EU/10(9 PFU (plaque forming units down to an average of 2.8 EU/10(9 PFU. The purification procedure is scalable, efficient and applicable to all the bacteriophages tested: T4, HAP1 (E. coli and F8 (P. aeruginosa.

  3. Scalable organic solvent free supercritical fluid spray drying process for producing dry protein formulations.

    Science.gov (United States)

    Nuchuchua, O; Every, H A; Hofland, G W; Jiskoot, W

    2014-11-01

    In this study, we evaluated the influence of supercritical carbon dioxide (scCO2) spray drying conditions, in the absence of organic solvent, on the ability to produce dry protein/trehalose formulations at 1:10 and 1:4 (w/w) ratios. When using a 4L drying vessel, we found that decreasing the solution flow rate and solution volume, or increasing the scCO2 flow rate resulted in a significant reduction in the residual water content in dried products (Karl Fischer titration). The best conditions were then used to evaluate the ability to scale the scCO2 spray drying process from 4L to 10L chamber. The ratio of scCO2 and solution flow rate was kept constant. The products on both scales exhibited similar residual moisture contents, particle morphologies (SEM), and glass transition temperatures (DSC). After reconstitution, the lysozyme activity (enzymatic assay) and structure (circular dichroism, HP-SEC) were fully preserved, but the sub-visible particle content was slightly increased (flow imaging microscopy, nanoparticle tracking analysis). Furthermore, the drying condition was applicable to other proteins resulting in products of similar quality as the lysozyme formulations. In conclusion, we established scCO2 spray drying processing conditions for protein formulations without an organic solvent that holds promise for the industrial production of dry protein formulations. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Preparation of silver colloid and enhancement of dispersion stability in organic solvent

    International Nuclear Information System (INIS)

    Kim, Ki Young; Choi, Young Tai; Seo, Dae Jong; Park, Seung Bin

    2004-01-01

    Silver colloid of nanometer size was prepared in liquid phase by a reduction method. AgNO 3 , FeSO 4 .7H 2 O, and Na 3 C 6 H 5 O 7 .2H 2 O were used as silver precursor, reducing agent and dispersing agent, respectively. As precursor concentration was decreased or the concentration of dispersing agent was increased, the prepared particle size was decreased from 180 nm to 20 nm. Apparently, the particle size seemed to be decreased with the increase of stirring rate, but it was confirmed by TEM that the size of primary particle remained the same. This result indicates that the uniformity of precursor concentration in the reactor affects the particle size and the stirring rate should be kept higher than the critical value to prevent the agglomeration of particles. In order to make the dispersion stability of the prepared silver colloid maintained even in non-polar organic solvent, electrodialysis technique was applied. As ionic species in colloidal solution were removed by electrodialysis, the dispersability of the colloid in the organic solvent of long carbon chain was confirmed to be increased

  5. Micellization behaviour and thermodynamic parameters of 12-2-12 gemini surfactant in (water + organic solvent) mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Batigoec, Cigdem [Department of Chemistry, Faculty of Sciences, Trakya University, 22030 Edirne (Turkey); Akbas, Halide, E-mail: hakbas34@yahoo.com [Department of Chemistry, Faculty of Sciences, Trakya University, 22030 Edirne (Turkey); Boz, Mesut [Department of Chemistry, Faculty of Sciences, Trakya University, 22030 Edirne (Turkey)

    2011-09-15

    Highlights: > The cmc and {alpha} values of surfactant increased with increasing solvent content and temperature. > The values of ({Delta}G{sub m}{sup 0}) are negative in all cases for the micelle formation becomes less favourable. > The values of negative enthalpy indicate importance of the London dispersion forces for the micellization. > The positive entropy is due to a contribution supplied from the solvent. - Abstract: The effect of organic solvents on micellization behaviour and thermodynamic parameters of a cationic gemini (dimeric) surfactant, C{sub 12}H{sub 25}(CH{sub 3}){sub 2}N{sup +}-(CH{sub 2}){sub 2}-N{sup +}(CH{sub 3}){sub 2}C{sub 12}H{sub 25}.2Br{sup -}, (12-2-12) was studied in aqueous solutions over the range of T = (293.15 to 323.15) K using the conductometric technique. Ethylene glycol (EG), dimethylsulfoxide (DMSO) and 1,4-dioxan (DO) were used as organic solvents with three different contents. The critical micelle concentration (cmc) and the degree of counter ion dissociation ({alpha}) of micelles in the water and in the (water + organic solvent) mixtures including 10%, 20%, and 30% solvent contents were determined. The standard Gibbs free energy ({Delta}G{sub m}{sup 0}), enthalpy ({Delta}H{sub m}{sup 0}) and entropy ({Delta}S{sub m}{sup 0}) of micellization were estimated from the temperature dependence of the cmc values. It was observed that the critical micelle concentration of the gemini surfactant and the degree of counter ion dissociation of the micelle increased as the volume percentage of organic solvent, and temperature increased. The standard Gibbs free energy of micellization was found to be less negative with the increase in the organic solvent content and temperature.

  6. Efficient production of fatty acid methyl ester from waste activated bleaching earth using diesel oil as organic solvent.

    Science.gov (United States)

    Kojima, Seiji; Du, Dongning; Sato, Masayasu; Park, Enoch Y

    2004-01-01

    Fatty acid methyl ester (FAME) production from waste activated bleaching earth (ABE) discarded by the crude oil refining industry was investigated using fossil fuel as a solvent in the esterification of triglycerides. Lipase from Candida cylindracea showed the highest stability in diesel oil. Using diesel oil as a solvent, 3 h was sufficient to obtain a yield of approximately 100% of FAME in the presence of 10% lipase from waste ABE. Kerosene was also a good solvent in the esterification of triglycerides embedded in the waste ABE. Fuel analysis showed that the FAME produced using diesel oil as a solvent complied with the Japanese diesel standard and the 10% residual carbon amount was lower than that of FAME produced using other solvents. Use of diesel oil as solvent in the FAME production from the waste ABE simplified the process, because there was no need to separate the organic solvent from the FAME-solvent mixture. These results demonstrate a promising reutilization method for the production of FAME, for use as a biodiesel, from industrial waste resources containing waste vegetable oils.

  7. Screening for organic solvents in Hanford waste tanks using total non- methane organic compound vapor concentrations

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Glissmeyer, J.A.; Sklarew, D.S.

    1997-02-01

    The potential ignition of organic liquids stored in the Hanford high-level radioactive waste tanks is a safety issue because expanding gases could affect tank dome integrity. This report presents results of a screening test that was applied to 75 passively ventilated waste tanks at Hanford to determine those that might contain a significant amount of organic liquid waste. The screening test is based on a simple model of tank headspace, headspace organic vapor concentrations, and certain tank physical parameters. Analyses indicate that damage to the tank dome is credible only if the organic liquid burn rate is above a threshold value, and this can occur only if the surface area of organic liquid in a tank is above a corresponding threshold value of about one square meter. Twelve tanks were identified as potentially containing at least that amount of semivolatile organic liquid based on conservative estimates. Tank head space organic vapor concentrations and physical parameters required by the screening test have been compiled and are presented for each of the tanks studied. Estimates of the ventilation rates of the waste tanks were revised to reflect recent information obtained from hydrogen monitoring data. A simple analysis of the uncertainty in the test results suggests that the largest current uncertainty in the estimation of organic liquid surface area is that associated with knowledge of the tank ventilation rate. The uncertainty analysis is applied to determine 95% confidence limits for the estimated organic waste surface area in each tank

  8. Radiation-Induced Polymerization of Butyl Acrylate for Recovery of Organic Solvents

    International Nuclear Information System (INIS)

    Kattan, M.; Al-Kassiri, H.

    2011-01-01

    Radiation-induced polymerization of butyl acrylate using 60 Co gamma rays has been investigated under different conditions, such as irradiation dose (0-130 kGy), dose rate (10 kGy/h), and temperature (25-70 degree C). A linear relationship between conversion and temperature of irradiation was found. The activation energy (E) of 9.37 kJ/mol was obtained from kinetic analysis of the result from the polymerization at 10 kGy/h. Thermal properties were examined using differential scanning calorimetry and thermal gravimetric analysis. Efficient extraction of organic solvents including chloroform, chlorobenzene, carbon tetrachloride, benzene, styrene was revealed by the swelling and releasing measurements. These results indicate the feasibility of applying this polymer, which was prepared by radiation-induced polymerization, to management of organic wastes in the field of environment. (author)

  9. Radiation-Induced Polymerization of Butyl Acrylate for Recovery of Organic Solvents

    International Nuclear Information System (INIS)

    Kattan, M.; Al-kassiri, H.

    2010-01-01

    Radiation-induced polymerization of butyl acrylate (BAc) using 60 Co gamma rays has been investigated under different conditions such as irradiation dose (0-130 kGy), dose rate (10 kGy/h) and temperature (25-70 C). A linear relationship between conversion and temperature of irradiation was found. The activation energy (E) of 9.37 kJ/mol was obtained from kinetic analysis of the result from the polymerization at 10 kGy/h. Thermal properties. were examined using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Efficient extraction of organic solvents including chloroform, chlorobenzene, carbon tetrachloride, benzene, styrene was revealed by the swelling and releasing measurements. These results indicate the feasibility of applying this polymer, which was prepared by radiation-induced polymerization, to management of organic wastes in the field of environment. (author)

  10. Solvent extraction of hafnium(IV) by dinonylnaphthalene sulfonic acid from mixed aqueous-organic media

    International Nuclear Information System (INIS)

    Hala, J.; Piperkovova, H.

    1979-01-01

    The extraction of hafnium(IV) by heptane and toluene solutions of dinonylnaphthalene sulfonic acid (HD) from mixed aqueous-organic solutions has been studied. Alcohols, ketones, carboxylic acids, cyclic ethers, dimethylsulfoxide and dimethylformamide were used as the organic component of the mixed phase. Methanol, ethanol, formic acid and dioxane increased the extractability of Hf(IV) whereas other solvents showed only an antagonistic effect. The results were discussed from the point of view of the changes in micellar structure of HD, and compared with the uptake of Hf(IV) by resinous cation exchangers. The solubilization by HD of alcohols, carboxylic acids and dimethylsulfoxide was demonstrated by using the corresponding 14 C and 35 S labelled compounds. (author)

  11. Modeling the Dispersibility of Single Walled Carbon Nanotubes in Organic Solvents by Quantitative Structure-Activity Relationship Approach

    Science.gov (United States)

    Yilmaz, Hayriye; Rasulev, Bakhtiyor; Leszczynski, Jerzy

    2015-01-01

    The knowledge of physico-chemical properties of carbon nanotubes, including behavior in organic solvents is very important for design, manufacturing and utilizing of their counterparts with improved properties. In the present study a quantitative structure-activity/property relationship (QSAR/QSPR) approach was applied to predict the dispersibility of single walled carbon nanotubes (SWNTs) in various organic solvents. A number of additive descriptors and quantum-chemical descriptors were calculated and utilized to build QSAR models. The best predictability is shown by a 4-variable model. The model showed statistically good results (R2training = 0.797, Q2 = 0.665, R2test = 0.807), with high internal and external correlation coefficients. Presence of the X0Av descriptor and its negative term suggest that small size solvents have better SWCNTs solubility. Mass weighted descriptor ATS6m also indicates that heavier solvents (and small in size) most probably are better solvents for SWCNTs. The presence of the Dipole Z descriptor indicates that higher polarizability of the solvent molecule increases the solubility. The developed model and contributed descriptors can help to understand the mechanism of the dispersion process and predictorganic solvents that improve the dispersibility of SWNTs. PMID:28347035

  12. Modeling the Dispersibility of Single Walled Carbon Nanotubes in Organic Solvents by Quantitative Structure-Activity Relationship Approach

    Directory of Open Access Journals (Sweden)

    Hayriye Yilmaz

    2015-05-01

    Full Text Available The knowledge of physico-chemical properties of carbon nanotubes, including behavior in organic solvents is very important for design, manufacturing and utilizing of their counterparts with improved properties. In the present study a quantitative structure-activity/property relationship (QSAR/QSPR approach was applied to predict the dispersibility of single walled carbon nanotubes (SWNTs in various organic solvents. A number of additive descriptors and quantum-chemical descriptors were calculated and utilized to build QSAR models. The best predictability is shown by a 4-variable model. The model showed statistically good results (R2training = 0.797, Q2 = 0.665, R2test = 0.807, with high internal and external correlation coefficients. Presence of the X0Av descriptor and its negative term suggest that small size solvents have better SWCNTs solubility. Mass weighted descriptor ATS6m also indicates that heavier solvents (and small in size most probably are better solvents for SWCNTs. The presence of the Dipole Z descriptor indicates that higher polarizability of the solvent molecule increases the solubility. The developed model and contributed descriptors can help to understand the mechanism of the dispersion process and predictorganic solvents that improve the dispersibility of SWNTs.

  13. 40 CFR Table 6 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Metal Cans Pt. 63, Subpt. KKKK, Table 6 Table 6 to Subpart KKKK of Part 63—Default Organic HAP Mass... blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent by mass 1. Toluene 108-88-3...

  14. Solvent extraction of organic acids from stillage for its re-use in ethanol production process.

    Science.gov (United States)

    Castro, G A; Caicedo, L A; Alméciga-Díaz, C J; Sanchez, O F

    2010-06-01

    Stillage re-use in the fermentation stage in ethanol production is a technique used for the reduction of water and fermentation nutrients consumption. However, the inhibitory effect on yeast growth of the by-products and feed components that remains in stillage increases with re-use and reduces the number of possible recycles. Several methods such as ultrafiltration, electrodialysis and advanced oxidation processes have been used in stillage treatment prior its re-use in the fermentation stage. Nevertheless, few studies evaluating the effect of solvent extraction as a stillage treatment option have been performed. In this work, the inhibitory effect of serial stillage recycling over ethanol and biomass production was determined, using acetic acid as a monitoring compound during the fermentation and solvent extraction process. Raw palm oil methyl ester showed the highest acetic acid extraction from the aqueous phase, presenting a distribution coefficient of 3.10 for a 1:1 aqueous phase mixture:solvent ratio. Re-using stillage without treatment allowed up to three recycles with an ethanol production of 53.7 +/- 2.0 g L(-1), which was reduced 25% in the fifth recycle. Alternatively, treated stillage allowed up to five recycles with an ethanol final concentration of 54.7 +/- 1.3 g L(- 1). These results show that reduction of acetic acid concentration by an extraction process with raw palm oil methyl ester before re-using stillage improves the number of recycles without a major effect on ethanol production. The proposed process generates a palm oil methyl ester that contains organic acids, among other by-products, that could be used for product recovery and as an alternative fuel.

  15. Physico-chemical properties of Pd nanoparticles produced by Pulsed Laser Ablation in different organic solvents

    International Nuclear Information System (INIS)

    Cristoforetti, Gabriele; Pitzalis, Emanuela; Spiniello, Roberto; Ishak, Randa; Giammanco, Francesco; Muniz-Miranda, Maurizio; Caporali, Stefano

    2012-01-01

    Palladium nanoparticles are arousing an increasing interest because of their strong activity in heterogeneous catalysis in a wide range of reactions. Driven by the interest of producing Pd nanoparticles to be deposited for catalysis over hydrophobic supports, we investigated their synthesis via Pulsed Laser Ablation in Liquid in several organic solvents, as acetone, ethanol, 2-propanol, toluene, n-hexane. The colloids were produced by using a Nd:YAG ns laser and without the addition of surfactant agents. The morphology, composition, stability and oxidation state of the obtained nanoparticles were investigated by TEM-EDS analysis, UV-vis spectroscopy, X-ray Photoelectron Spectroscopy and micro-Raman spectroscopy. The results evidence that the nature of the solvent influences both the yield and the physico-chemical properties of the produced nanoparticles. While in acetone and alcohols spheroidal, non aggregated and stable particles are obtained, in case of toluene and n-hexane few unstable particles surrounded by a gel-like material are produced. Raman/XPS measurements suggest the presence of amorphous or graphitic carbon onto crystalline Pd nanoparticles, which could have hindered their growth and determined the observed smaller sizes if compared to nanoparticles produced in water. The stability of Pd colloids obtained in acetone and alcohols was attributed to adsorbed anions like enolates or alcoholates; non polar solvents like toluene and n-hexane, unable to give rise to adsorbed anionic species, cannot provide any stabilization to the palladium nanoparticles. XPS analyses also evidenced a partial oxidation of particles surface, with a ratio Pd 2+ :Pd 0 of 1:2.5 and 1:4 in acetone and ethanol, respectively.

  16. Thermodynamic Stability Analysis of Tolbutamide Polymorphs and Solubility in Organic Solvents.

    Science.gov (United States)

    Svärd, Michael; Valavi, Masood; Khamar, Dikshitkumar; Kuhs, Manuel; Rasmuson, Åke C

    2016-06-01

    Melting temperatures and enthalpies of fusion have been determined by differential scanning calorimetry (DSC) for 2 polymorphs of the drug tolbutamide: FI(H) and FV. Heat capacities have been determined by temperature-modulated DSC for 4 polymorphs: FI(L), FI(H), FII, FV, and for the supercooled melt. The enthalpy of fusion of FII at its melting point has been estimated from the enthalpy of transition of FII into FI(H) through a thermodynamic cycle. Calorimetric data have been used to derive a quantitative polymorphic stability relationship between these 4 polymorphs, showing that FII is the stable polymorph below approximately 333 K, above which temperature FI(H) is the stable form up to its melting point. The relative stability of FV is well below the other polymorphs. The previously reported kinetic reversibility of the transformation between FI(L) and FI(H) has been verified using in situ Raman spectroscopy. The solid-liquid solubility of FII has been gravimetrically determined in 5 pure organic solvents (methanol, 1-propanol, ethyl acetate, acetonitrile, and toluene) over the temperature range 278 to 323 K. The ideal solubility has been estimated from calorimetric data, and solution activity coefficients at saturation in the 5 solvents determined. All solutions show positive deviation from Raoult's law, and all van't Hoff plots of solubility data are nonlinear. The solubility in toluene is well below that observed in the other investigated solvents. Solubility data have been correlated and extrapolated to the melting point using a semiempirical regression model. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  17. Stabilization of Rocky Flats combustible residues contaminated with plutonium metal and organic solvents

    International Nuclear Information System (INIS)

    Bowen, S.M.; Cisneros, M.R.; Jacobson, L.L.; Schroeder, N.C.; Ames, R.L.

    1998-01-01

    This report describes tests on a proposed flowsheet designed to stabilize combustible residues that were generated at the Rocky Flats Environmental Technology Site (RFETS) during the machining of plutonium metal. Combustible residues are essentially laboratory trash contaminated with halogenated organic solvents and plutonium metal. The proposed flowsheet, designed by RFETS, follows a glovebox procedure that includes (1) the sorting and shredding of materials, (2) a low temperature thermal desorption of solvents from the combustible materials, (3) an oxidation of plutonium metal with steam, and (4) packaging of the stabilized residues. The role of Los Alamos National Laboratory (LANL) in this study was to determine parameters for the low temperature thermal desorption and steam oxidation steps. Thermal desorption of carbon tetrachloride (CCl 4 ) was examined using a heated air stream on a Rocky Flats combustible residue surrogate contaminated with CCl 4 . Three types of plutonium metal were oxidized with steam in a LANL glovebox to determine the effectiveness of this procedure for residue stabilization. The results from these LANL experiments are used to recommend parameters for the proposed RFETS stabilization flowsheet

  18. Engymatic synthesis of aspartame precursor in organic solvent; Yuki yobaichu deno asuparutemu zenkutai no koso gosei

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, K. [Okayama Univ., Okayama (Japan). Faculty of Engineering

    1996-11-05

    Taking up the synthetic reaction of the precursor of artificial sweetener aspartame for which thermolysin is used as the catalyst, the features and problems of enzymatic reaction in organic solvent are discussed. It is found that immobilized enzyme which has high activity and stability can be prepared by adsorbing high concentration thermolysin in Amberlite XAD7 followed by bridge immobilization. The initial rate of the synthesis and the stability of immobilized enzyme depend on the types of solvents. Continuous reaction is attempted using a columnar ferment reactor (PFR) in ethyl acetate at the beginning, but the yield decreases in a short period because the immobilized enzyme lose its activity gradually from the upper area of the column where Z-Asp concentration is high. When CSTR (complete mixed type reactor) is used, deactivation of immobilized enzyme can be restricted because low Z-Asp concentration in the reactor can be maintained. It is demonstrated that continuous reaction of longer than 200 hours is possible although the reaction rate is as low as 90%. 4 refs., 3 figs., 1 tab.

  19. Parameters Affecting the Synthesis of (Z)-3-hexen-1-yl acetate by Transesterifacation in Organic Solvent

    International Nuclear Information System (INIS)

    Liaquat, M.; Mehmood, T.; Khan, S. U.; Ahmed, Z.; Saeed, M.; Aslam, S.; Khan, J.; Ali, N.; Jahangir, M.; Nawaz, M.

    2015-01-01

    (Z)-3-hexen-1-yl esters are important green top-note components of food flavors and fragrances. Crude acetone powders extracted lipases from five plant seedlings of rapeseed, wheat, barley, linseed and maize were investigated for their use in the synthesis of flavor esters with vinyl acetate by transesterification in organic solvents. Rape seedlings showed the highest degree of (Z)-3-hexen-1-yl acetate synthesis with a yield of 76 percentage in 72 h. Rape seedling was chosen as promising biocatalyst to evaluate the effects of some of reaction parameters on (Z)-3-hexen-1-yl acetate synthesis using vinyl acetate and (Z)-3-hexen-1-ol at 40 Degree C in n-hexane with 50 g/L enzyme as catalyst. Acetonitrile proved distinctly superior solvent. The percent remaining activity relative to fresh seedlings powders was highest in wheat and barley. Highest ester yield of 80 percentage was obtained with 0.8 M of substrate concentrations within 48 h. Crude rapeseed lipase afforded a conversion 93 percentage of ethyl alcohol. Higher ester yield was achieved within first 24 h with added molecular. The crude rape seedlings lipase is low cost yet effective, showed potential for the production of green note esters industrially. (author)

  20. Generalized syntheses of nanocrystal-graphene hybrids in high-boiling-point organic solvents.

    Science.gov (United States)

    Pang, Danny Wei-Ping; Yuan, Fang-Wei; Chang, Yan-Cheng; Li, Guo-An; Tuan, Hsing-Yu

    2012-08-07

    Nanocrystal-graphene have been proposed as a new kind of promising hybrid for a wide range of application areas including catalysts, electronics, sensors, biomedicine, and energy storage, etc. Although a variety of methods have been developed for the preparation of hybrids, a facile and general synthetic approach is still highly required. In this study, nanocrystal-graphene hybrids were successfully synthesized in high-boiling-point organic solvents. Graphene oxide (GO) nanosheets were modified by oleylamine (OLA) to form a OLA-GO complex in order to be readily incorporated into hydrophobic synthesis. A rich library of highly crystalline nanocrystals, with types including noble metal, metal oxide, magnetic material and semiconductor were successfully grown on chemically converted graphene (CCG), which is simultaneously reduced from GO during the synthesis. High boiling-point solvents afford sufficient thermal energy to assure the high-quality crystalline nature of NCs, therefore the post-annealing process is obviated. Controlled experiments revealed that OLA-GO triggers heterogeneous nucleation and serves as excellent nuclei anchorage media. The protocol developed here brings one step closer to achieve "unity in diversity" on the preparation of nanocrystal-graphene hybrids.

  1. Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization

    Science.gov (United States)

    Zhang, Yu-Qing; Shen, Wei-De; Xiang, Ru-Li; Zhuge, Lan-Jian; Gao, Wei-Jian; Wang, Wen-Bao

    2007-10-01

    When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl2, the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35-125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the ɛ-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and α-helix form (Silk I) into anti-parallel β-sheet form (Silk II) are investigated in detail by using infrared, fluorescence and Raman spectroscopy, DSC, 13C CP-MAS NMR and electron diffraction. X-ray diffraction of the silk nanoparticles shows that the nanoparticles crystallinity is about four fifths of the native fiber. Our results indicate that the degraded peptide chains of the regenerated silk is gathered homogeneously or heterogeneously to form a looser globular structure in aqueous solution. When introduced into excessive organic solvent, the looser globules of the liquid silk are rapidly dispersed and simultaneously dehydrated internally and externally, resulting in the further chain-chain contact, arrangement of those hydrophobic domains inside the globules and final formation of crystalline silk nanoparticles with β-sheet configuration. The morphology and size of the nanoparticles are relative to the kinds, properties and even molecular structures of organic solvents, and more significantly to the looser globular substructure of the degraded silk

  2. Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization

    International Nuclear Information System (INIS)

    Zhang Yuqing; Shen Weide; Xiang Ruli; Zhuge Lanjian; Gao Weijian; Wang Wenbao

    2007-01-01

    When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl 2 , the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35-125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the ε-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and α-helix form (Silk I) into anti-parallel β-sheet form (Silk II) are investigated in detail by using infrared, fluorescence and Raman spectroscopy, DSC, 13 C CP-MAS NMR and electron diffraction. X-ray diffraction of the silk nanoparticles shows that the nanoparticles crystallinity is about four fifths of the native fiber. Our results indicate that the degraded peptide chains of the regenerated silk is gathered homogeneously or heterogeneously to form a looser globular structure in aqueous solution. When introduced into excessive organic solvent, the looser globules of the liquid silk are rapidly dispersed and simultaneously dehydrated internally and externally, resulting in the further chain-chain contact, arrangement of those hydrophobic domains inside the globules and final formation of crystalline silk nanoparticles with β-sheet configuration. The morphology and size of the nanoparticles are relative to the kinds, properties and even molecular structures of organic solvents, and more significantly to the looser globular substructure of the degraded silk

  3. Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yuqing, E-mail: yqzhang@public1.sz.js.cn; Shen Weide; Xiang Ruli [Soochow University, Silk Biotechnol. Lab., School of Life Science (China); Zhuge Lanjian; Gao Weijian; Wang Wenbao [Soochow University, Analytical Center (China)

    2007-10-15

    When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl{sub 2}, the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35-125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the {epsilon}-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and {alpha}-helix form (Silk I) into anti-parallel {beta}-sheet form (Silk II) are investigated in detail by using infrared, fluorescence and Raman spectroscopy, DSC, {sup 13}C CP-MAS NMR and electron diffraction. X-ray diffraction of the silk nanoparticles shows that the nanoparticles crystallinity is about four fifths of the native fiber. Our results indicate that the degraded peptide chains of the regenerated silk is gathered homogeneously or heterogeneously to form a looser globular structure in aqueous solution. When introduced into excessive organic solvent, the looser globules of the liquid silk are rapidly dispersed and simultaneously dehydrated internally and externally, resulting in the further chain-chain contact, arrangement of those hydrophobic domains inside the globules and final formation of crystalline silk nanoparticles with {beta}-sheet configuration. The morphology and size of the nanoparticles are relative to the kinds, properties and even molecular structures of organic solvents, and more significantly to the looser globular

  4. On the Evaporation Kinetics of [60] Fullerene in Aromatic Organic Solvents

    KAUST Repository

    Amer, Maher S.; Wang, Wenhu; Kollins, Kaitlin N; Altalebi, Hasanain; Schwingenschlö gl, Udo

    2018-01-01

    We investigate the effect of C60 fullerene nanospheres on the evaporation kinetics of a number of aromatic solvents with different levels of molecular association, namely, benzene, toluene, and chlorobenzene. The dependence of the evaporation rate on the fullerene concentration is not monotonic but rather exhibits maxima and minima. The results strongly support the notion of molecular structuring within the liquid solvent controlled by the nature of fullerene/solvent interaction and the level of molecular association within the solvent itself.

  5. On the Evaporation Kinetics of [60] Fullerene in Aromatic Organic Solvents

    KAUST Repository

    Amer, Maher S.

    2018-04-03

    We investigate the effect of C60 fullerene nanospheres on the evaporation kinetics of a number of aromatic solvents with different levels of molecular association, namely, benzene, toluene, and chlorobenzene. The dependence of the evaporation rate on the fullerene concentration is not monotonic but rather exhibits maxima and minima. The results strongly support the notion of molecular structuring within the liquid solvent controlled by the nature of fullerene/solvent interaction and the level of molecular association within the solvent itself.

  6. Controlled release of beta-estradiol from PLAGA microparticles: the effect of organic phase solvent on encapsulation and release.

    Science.gov (United States)

    Birnbaum, D T; Kosmala, J D; Henthorn, D B; Brannon-Peppas, L

    2000-04-03

    To determine the effect of the organic solvent used during microparticle preparation on the in vitro release of beta-estradiol, a number of formulations were evaluated in terms of size, shape and drug delivery performance. Biodegradable microparticles of poly(lactide-co-glycolide) were prepared containing beta-estradiol that utilized dichloromethane, ethyl acetate or a mixture of dichloromethane and methanol as the organic phase solvent during the particle preparation. The drug delivery behavior from the microparticles was studied and comparisons were made of their physical properties for different formulations. The varying solubilities of beta-estradiol and poly(lactide-co-glycolide) in the solvents studied resulted in biodegradable microparticles with very different physical characteristics. Microparticles prepared from solid suspensions of beta-estradiol using dichloromethane as the organic phase solvent were similar in appearance to microparticles prepared without drug. Microparticles prepared from dichloromethane/methanol solutions appeared transparent to translucent depending on the initial amount of drug used in the formulation. Microparticles prepared using ethyl acetate appeared to have the most homogeneous encapsulation of beta-estradiol, appearing as solid white spheres regardless of initial drug content. Studies showed that microparticles prepared from either ethyl acetate or a mixture of dichloromethane and methanol gave a more constant release profile of beta-estradiol than particles prepared using dichloromethane alone. For all formulations, an initial burst of release increased with increasing drug loading, regardless of the organic solvent used.

  7. Kinetic Model of Resin-Catalyzed Decomposition of Acetone Cyanohydrin in Organic Solvent

    Institute of Scientific and Technical Information of China (English)

    章亭洲; 杨立荣; 朱自强; 吴坚平

    2003-01-01

    Decomposition of acetone cyanohydrin is the first-step reaction for preparing (S)-α-cyano-3-phenoxybenzyl alcohol (CPBA) by the one-pot method in organic media. Considering the compatibility of biocatalysts with chemical catalysts and the successive operation in the bioreactor, anion exchange resin (D301) was used as catalyst for this reaction. External diffusion limitation was excluded by raising rotational speed to higher than 190r·min-1 in both solvents. Internal diffusion limitation was verified to be insignificant in this reaction system. The effect of acetone cyanohydrin concentration on the reaction was also investigated. An intrinsic kinetic model was proposed when the mass transfer limitation was excluded, and the average deviation of the model is 10.5%.

  8. Pregnancy outcome after risk assessment of occupational exposure to organic solvents: a prospective cohort study.

    Science.gov (United States)

    Testud, François; D'Amico, Andrea; Lambert-Chhum, Rachel; Garayt, Christelle; Descotes, Jacques

    2010-11-01

    A rational medical, occupational and toxicological approach is instrumental to select objectively among pregnant women exposed to chemicals at the workplace those who should be withdrawn or benefit from improvements of working conditions. Risk assessment is based on a comprehensive review of compounds' hazards and a thorough evaluation of the actual exposure including biomonitoring whenever as possible. Since 1996, the Lyon Poison Center has been conducting a prospective follow-up of pregnant women exposed to chemicals at the workplace. Of these, 206 exposed to organic solvents since conception were selected and matched with 206 exposed to a non-embryotoxic agent. Total withdrawal from the workplace was recommended in 22% of cases, but exposure was not considered to be hazardous to pregnancy in 51%. Overall, no increase in adverse outcomes was found. Maintaining pregnant women at their workplace, particularly most of the laboratory technicians, is reasonably possible after careful toxicological risk assessment. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. [13N]ammonia in organic solvents; a potent synthetic precursor for 13N-labeling

    International Nuclear Information System (INIS)

    Tominaga, Toshiyoshi; Hirobe, Masaaki

    1987-01-01

    13 NH 3 in an organic solvent was prepared and its utility as a labeling precursor was studied. [ 13 N]adenine ([ 13 N]ADN), [ 13 N]nicotinamide ([ 13 N]NAM), [ 13 N]p-nitrophenyl carbamate ([ 13 N]NPC), and [ 13 N]L-glutamine ([ 13 N]Gln) were labeled utilizing this precursor. [ 13 N]ADN and [ 13 N]NAM were labeled in much better yields than from an aqueous solution of 13 NH 3 . [ 13 N]NPC and [ 13 N]Gln, which could not be labeled in an aqueous solution, were labeled in high radiochemical yields. Thus, the advantages of this precursor are the improvement of the labeling yield and the feasibility of labeling compounds unstable in aqueous conditions. (author)

  10. Thermodynamic study of the transfer of acetanilide and phenacetin from water to different organic solvents.

    Science.gov (United States)

    Baena, Yolima; Pinzón, Jorge A; Barbosa, Helber J; Martínez, Fleming

    2005-06-01

    The molar (K(C)(o/w)) and rational (K(X)(o/w)) partition coefficients in the octanol/buffer, i-propyl myristate/buffer, chloroform/buffer, and cyclohexane/buffer systems were determined for acetanilide and phenacetin at 25.0, 30.0, 35.0, and 40.0 degrees C. In all cases except for cyclohexane, the K(C)(o/w) and K(X)(o/w) values were greater than unity. This demonstrates that these two drugs have predominantly lipophilic behavior. Gibbs and van't Hoff thermodynamic analyses have revealed that the transfer of these drugs from water to organic solvents is spontaneous and that it is mainly driven enthalpically for i-propyl myristate and chloroform, and entropy-driven for octanol and cyclohexane.

  11. Fabrication of 3D photonic crystals from chitosan that are responsive to organic solvents.

    Science.gov (United States)

    Huang, Guanbo; Yin, Yibing; Pan, Zeng; Chen, Mingxi; Zhang, Lei; Liu, Yu; Zhang, Yongli; Gao, Jianping

    2014-12-08

    Inspired by photonic nanostructures in nature, such as the hair-like chaetae on the body of sea mice, inverse opal photonic crystals films were fabricated with chitosan, a kind of biomacromolecule found in nature. First, monodispersed polystyrene (PS) colloidal crystal templates with different particle sizes were prepared. The inverse opal films (IOFs) were fabricated through in situ cross-linking of the PS templates. The IOFs contain periodically ordered interconnecting pores that endow the films with photonic stop bands and structural colors, which are visible to the naked eye. The IOFs exhibit rapid reversible changes in their structural colors and reflectance peaks in response to alcohols and phenols. Possible mechanisms for the shifts in the IOF's reflectance peaks are proposed. The changes in the IOFs in response to alcohols and phenols provide a potential way to visually detect these organic solvents.

  12. Solvent effects of a dimethyldicyanoquinonediimine buffer layer as N-type material on the performance of organic photovoltaic cells.

    Science.gov (United States)

    Yang, Eui Yeol; Oh, Se Young

    2014-08-01

    In the present work, we have fabricated organic photovoltaic cells consisting of ITO/PEDOT:PSS/P3HT:PCBM/DMDCNQI/Al using a dip-coating method with various solvent systems. We have investigated solvent effects (such as solubility, viscosity and vapor pressure) in deposition of a thin DMDCNQI buffer layer on the performance of organic photovoltaic cells. The solvent system which had low viscosity and good solubility properties, made a dense and uniform DMDCNQI ultra thin film, resulting in a high performance device. In particular, a prepared organic photovoltaic cell was fabricated using a cosolvent system (methanol:methylenechloride = 3:1) and showed a maximum power conversion efficiency of 4.53%.

  13. Staining of proteins in gels with Coomassie G-250 without organic solvent and acetic acid.

    Science.gov (United States)

    Lawrence, Ann-Marie; Besir, H Uuml Seyin

    2009-08-14

    In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents (Methanol, Ethanol or 2-Propanol) and acetic acid are used for fixation, staining and destaining of proteins in a gel after SDS-PAGE. To speed up the procedure, heating the staining solution in the microwave oven for a short time is frequently used. This usually results in evaporation of toxic or hazardous Methanol, Ethanol or 2-Propanol and a strong smell of acetic acid in the lab which should be avoided due to safety considerations. In a protocol originally published in two patent applications by E.M. Wondrak (US2001046709 (A1), US6319720 (B1)), an alternative composition of the staining solution is described in which no organic solvent or acid is used. The CBB is dissolved in bidistilled water (60-80 mg of CBB G-250 per liter) and 35 mM HCl is added as the only other compound in the staining solution. The CBB staining of the gel is done after SDS-PAGE and thorough washing of the gel in bidistilled water. By heating the gel during the washing and staining steps, the process can be finished faster and no toxic or hazardous compounds are evaporating. The staining of proteins occurs already within 1 minute after heating the gel in staining solution and is fully developed after 15-30 min with a slightly blue background that is destained completely by prolonged washing of the stained gel in bidistilled water, without affecting the stained protein bands.

  14. Occupational exposure to organic solvents: a risk factor for pulmonary veno-occlusive disease.

    Science.gov (United States)

    Montani, David; Lau, Edmund M; Descatha, Alexis; Jaïs, Xavier; Savale, Laurent; Andujar, Pascal; Bensefa-Colas, Lynda; Girerd, Barbara; Zendah, Inès; Le Pavec, Jerome; Seferian, Andrei; Perros, Frédéric; Dorfmüller, Peter; Fadel, Elie; Soubrier, Florent; Sitbon, Oliver; Simonneau, Gérald; Humbert, Marc

    2015-12-01

    Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary hypertension characterised by predominant remodelling of pulmonary venules. Bi-allelic mutations in the eukaryotic translation initiation factor 2α kinase 4 (EIF2AK4) gene were recently described as the major cause of heritable PVOD, but risk factors associated with PVOD remain poorly understood. Occupational exposures have been proposed as a potential risk factor for PVOD, but epidemiological studies are lacking.A case-control study was conducted in consecutive PVOD (cases, n=33) and pulmonary arterial hypertension patients (controls, n=65). Occupational exposure was evaluated via questionnaire interview with blinded assessments using an expert consensus approach and a job exposure matrix (JEM).Using the expert consensus approach, PVOD was significantly associated with occupational exposure to organic solvents (adjusted OR 12.8, 95% CI 2.7-60.8), with trichloroethylene being the main agent implicated (adjusted OR 8.2, 95% CI 1.4-49.4). JEM analysis independently confirmed the association between PVOD and trichloroethylene exposure. Absence of significant trichloroethylene exposure was associated with a younger age of disease (54.8±21.4 years, p=0.037) and a high prevalence of harbouring bi-allelic EIF2AK4 mutations (41.7% versus 0%, p=0.015).Occupational exposure to organic solvents may represent a novel risk factor for PVOD. Genetic background and environmental exposure appear to influence the phenotypic expression of the disease. Copyright ©ERS 2015.

  15. Photochemical reactions of brominated diphenylethers in organic solvents and adsorbed on silicon dioxide in aqueous suspension

    Energy Technology Data Exchange (ETDEWEB)

    Palm, W.U.; Kopetzky, R.; Sossinka, W.; Ruck, W. [Univ. of Lueneburg, Environmental Chemistry, Lueneburg (Germany); Zetzsch, C. [Univ. of Bayreuth, Atmos. Chem. Research, Bayreuth, and Fraunhofer-Inst. of Toxicology and Experimental Medicine, Hannover (Germany)

    2004-09-15

    Polybrominated diphenylethers (BDEs) are in use as flame retardants worldwide and are found as xenobiotics in environmental samples. Photolysis by sunlight, one of the potential abiotic degradation pathways, is found to be rapid in laboratory experiments, especially for deca-BDE, the most prominent BDE as compared to commercial penta- and octa-BDEs. Due to the extremely low water solubility of BDEs, these experiments were mostly performed in organic solvents so far, and a few in environmental matrices (sand and soil) and on dry and hydrated quartz glass. However, detailed UV absorption spectra of deca-BDE and debrominated BDEs in the relevant wavelength range above 300 nm have become available only recently, besides the UV maxima of a number of synthesized congeners at shorter wavelengths and an exploratory study from our laboratory. Other important parameters to assess the abiotic degradation in the environment, such as OH-rate constants and photolytic quantum yields of BDEs are not available. Furthermore, analysis of BDEs was mostly performed by GC-MS, and the capability of HPLC with a diode array detector (DAD) has not yet been exploited. This study presents kinetic results on the photolysis of BDEs in tetrahydrofuran (THF) with detailed photolytic pathways for a tetra-BDE (2,2'4,4'-BDE), a hexa-BDE (2,2'4,4',5,5'-BDE) and deca-BDE. Employing HPLC with a diode array detector (DAD) as analytical tool, quantum yields of BDEs with N{sub Br} = 1-10 are determined. Furthermore, the formation of brominated dibenzofurans (BDFs) was investigated. Since the environmental relevance of photolysis experiments in organic solvents is questionable, first results on photolysis of deca-BDE adsorbed on silicon dioxide particles, suspended in water, are presented.

  16. Noise-induced hearing loss in Korean workers: co-exposure to organic solvents and heavy metals in nationwide industries.

    Directory of Open Access Journals (Sweden)

    Yoon-Hyeong Choi

    Full Text Available BACKGROUND: Noise exposure is a well-known contributor to work-related hearing loss. Recent biological evidence suggests that exposure to ototoxic chemicals such as organic solvents and heavy metals may be additional contributors to hearing loss. However, in industrial settings, it is difficult to determine the risks of hearing loss due to these chemicals in workplaces accompanied by excessive noise exposure. A few studies suggest that the effect of noise may be enhanced by ototoxic chemicals. Therefore, this study investigated whether co-exposure to organic solvents and/or heavy metals in the workplace modifies the risk of noise exposure on hearing loss in a background of excessive noise. METHODS: We examined 30,072 workers nationwide in a wide range of industries from the Korea National Occupational Health Surveillance 2009. Data on industry-based exposure (e.g., occupational noise, heavy metals, and organic solvents and subject-specific health outcomes (e.g., audiometric examination were collected. Noise was measured as the daily 8-h time-weighted average level. Air conduction hearing thresholds were measured from 0.5 to 6 kHz, and pure-tone averages (PTA (i.e., means of 2, 3, and 4 kHz were computed. RESULTS: In the multivariate linear model, PTA increment with occupational noise were 1.64-fold and 2.15-fold higher in individuals exposed to heavy metals and organic solvents than in unexposed individuals, respectively. CONCLUSION: This study provides nationwide evidence that co-exposure to heavy metals and/or organic solvents may exacerbate the effect of noise exposure on hearing loss in workplaces. These findings suggest that workers in industries dealing with heavy metals or organic solvents are susceptible to such risks.

  17. Noise-induced hearing loss in Korean workers: co-exposure to organic solvents and heavy metals in nationwide industries.

    Science.gov (United States)

    Choi, Yoon-Hyeong; Kim, KyooSang

    2014-01-01

    Noise exposure is a well-known contributor to work-related hearing loss. Recent biological evidence suggests that exposure to ototoxic chemicals such as organic solvents and heavy metals may be additional contributors to hearing loss. However, in industrial settings, it is difficult to determine the risks of hearing loss due to these chemicals in workplaces accompanied by excessive noise exposure. A few studies suggest that the effect of noise may be enhanced by ototoxic chemicals. Therefore, this study investigated whether co-exposure to organic solvents and/or heavy metals in the workplace modifies the risk of noise exposure on hearing loss in a background of excessive noise. We examined 30,072 workers nationwide in a wide range of industries from the Korea National Occupational Health Surveillance 2009. Data on industry-based exposure (e.g., occupational noise, heavy metals, and organic solvents) and subject-specific health outcomes (e.g., audiometric examination) were collected. Noise was measured as the daily 8-h time-weighted average level. Air conduction hearing thresholds were measured from 0.5 to 6 kHz, and pure-tone averages (PTA) (i.e., means of 2, 3, and 4 kHz) were computed. In the multivariate linear model, PTA increment with occupational noise were 1.64-fold and 2.15-fold higher in individuals exposed to heavy metals and organic solvents than in unexposed individuals, respectively. This study provides nationwide evidence that co-exposure to heavy metals and/or organic solvents may exacerbate the effect of noise exposure on hearing loss in workplaces. These findings suggest that workers in industries dealing with heavy metals or organic solvents are susceptible to such risks.

  18. Noise-Induced Hearing Loss in Korean Workers: Co-Exposure to Organic Solvents and Heavy Metals in Nationwide Industries

    Science.gov (United States)

    Choi, Yoon-Hyeong; Kim, KyooSang

    2014-01-01

    Background Noise exposure is a well-known contributor to work-related hearing loss. Recent biological evidence suggests that exposure to ototoxic chemicals such as organic solvents and heavy metals may be additional contributors to hearing loss. However, in industrial settings, it is difficult to determine the risks of hearing loss due to these chemicals in workplaces accompanied by excessive noise exposure. A few studies suggest that the effect of noise may be enhanced by ototoxic chemicals. Therefore, this study investigated whether co-exposure to organic solvents and/or heavy metals in the workplace modifies the risk of noise exposure on hearing loss in a background of excessive noise. Methods We examined 30,072 workers nationwide in a wide range of industries from the Korea National Occupational Health Surveillance 2009. Data on industry-based exposure (e.g., occupational noise, heavy metals, and organic solvents) and subject-specific health outcomes (e.g., audiometric examination) were collected. Noise was measured as the daily 8-h time-weighted average level. Air conduction hearing thresholds were measured from 0.5 to 6 kHz, and pure-tone averages (PTA) (i.e., means of 2, 3, and 4 kHz) were computed. Results In the multivariate linear model, PTA increment with occupational noise were 1.64-fold and 2.15-fold higher in individuals exposed to heavy metals and organic solvents than in unexposed individuals, respectively. Conclusion This study provides nationwide evidence that co-exposure to heavy metals and/or organic solvents may exacerbate the effect of noise exposure on hearing loss in workplaces. These findings suggest that workers in industries dealing with heavy metals or organic solvents are susceptible to such risks. PMID:24870407

  19. Room-temperature solid phase ionic liquid (RTSPIL) coated Ω-transaminases: Development and application in organic solvents

    DEFF Research Database (Denmark)

    Grabner, B.; Nazario, M. A.; Gundersen, M. T.

    2018-01-01

    ω-Transaminases ATA-40, ATA-47 and ATA-82P were coated with room-temperature solid phase ionic liquids (RTSPILs) by means of three methods, melt coating, precipitation coating, and co‐lyophilization, and showed increased stability in all of the five tested organic solvents. Co‐lyophilization and ......ω-Transaminases ATA-40, ATA-47 and ATA-82P were coated with room-temperature solid phase ionic liquids (RTSPILs) by means of three methods, melt coating, precipitation coating, and co‐lyophilization, and showed increased stability in all of the five tested organic solvents. Co...

  20. Zero-Energy Ultrafast Water Nanofiltration System in Microgravity

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this program is to develop a water nanofiltration system that functions in microgravity for use during a long-duration human space exploration. The...

  1. Optimization of the solvent-based dissolution method to sample volatile organic compound vapors for compound-specific isotope analysis.

    Science.gov (United States)

    Bouchard, Daniel; Wanner, Philipp; Luo, Hong; McLoughlin, Patrick W; Henderson, James K; Pirkle, Robert J; Hunkeler, Daniel

    2017-10-20

    The methodology of the solvent-based dissolution method used to sample gas phase volatile organic compounds (VOC) for compound-specific isotope analysis (CSIA) was optimized to lower the method detection limits for TCE and benzene. The sampling methodology previously evaluated by [1] consists in pulling the air through a solvent to dissolve and accumulate the gaseous VOC. After the sampling process, the solvent can then be treated similarly as groundwater samples to perform routine CSIA by diluting an aliquot of the solvent into water to reach the required concentration of the targeted contaminant. Among solvents tested, tetraethylene glycol dimethyl ether (TGDE) showed the best aptitude for the method. TGDE has a great affinity with TCE and benzene, hence efficiently dissolving the compounds during their transition through the solvent. The method detection limit for TCE (5±1μg/m 3 ) and benzene (1.7±0.5μg/m 3 ) is lower when using TGDE compared to methanol, which was previously used (385μg/m 3 for TCE and 130μg/m 3 for benzene) [2]. The method detection limit refers to the minimal gas phase concentration in ambient air required to load sufficient VOC mass into TGDE to perform δ 13 C analysis. Due to a different analytical procedure, the method detection limit associated with δ 37 Cl analysis was found to be 156±6μg/m 3 for TCE. Furthermore, the experimental results validated the relationship between the gas phase TCE and the progressive accumulation of dissolved TCE in the solvent during the sampling process. Accordingly, based on the air-solvent partitioning coefficient, the sampling methodology (e.g. sampling rate, sampling duration, amount of solvent) and the final TCE concentration in the solvent, the concentration of TCE in the gas phase prevailing during the sampling event can be determined. Moreover, the possibility to analyse for TCE concentration in the solvent after sampling (or other targeted VOCs) allows the field deployment of the sampling

  2. Organic solvents improve hydrocarbon desorption and biodegradation in highly contaminated weathered soils

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Rivero, M. [Tecnologico de Estudios Superiores de Ecatepec, Mexico City (Mexico); Saucedo-Casteneda, G.; Gutierrez-Rojas, M. [Autonoma Metropolitan Univ., Mexico City (Mexico). Dept. of Biotechnology

    2007-07-15

    A toluene-based microbial slurry phase system was used to remediate hydrocarbons (HC) in highly contaminated soil samples collected from a site next to a working refinery in Mexico. Initial HC concentrations of the samples were 237.2 {+-} 16,6 g kg{sup -1} in dry soil. The microbial consortium consisted of 10 different strains in a mineral solution. Non-polar solvents used in the phase system included hexane, benzene, and toluene. Polar solvents included n-butanol, acetone, and methanol. The bioavailability of the HCs was increased using both polar and nonpolar solvents in order to promote desorption from the soil and to enhance overall HC biodegradation. HC desorption was analyzed in an abiotic system. Respiration and residual HCs were examined after a period of 30 days in order to compare the effects of the 2 solvents. The biodegradation extracts were then fractionated in a silica gel column to determine if the solvents actually enhanced the biodegradation of specific HC fractions. The study showed that induced dipole interactions forces resulted when nonpolar molecules were dissolved into a nonpolar solvent. Results for desorption and solubility varied among the 6 solvents. Higher dielectric constants resulted in higher solubility and desorption of HCs for nonpolar solvents, while the opposite effect was observed for polar solvents. It was concluded that toluene produced better biodegradation results than any of the milder solvents. 34 refs., 4 tabs., 1 fig.

  3. Urinary metabolite levels and symptoms in Filipino workers using organic solvents.

    Science.gov (United States)

    Cucueco, M T; Espinosa, N C; Villanueva, M B; Castro, F T; Sison, S Y; Ortega, V S; Hisanaga, N

    1993-01-01

    To compare symptoms with urinary metabolite levels, 900 workers from 7 organic solvent-using industries were studied. Urinary metabolites were determined using a high performance liquid chromatograph. Urinary hippuric acid concentrations exceeding the reference value (2.5 g/g creatinine) were found in 78 (8.7%) workers. However, only 3 (0.3%) and 1 (0.1%) of the participants exceeded the reference value for mandelic (0.8 g/g creatinine) and total methylhippuric acid (1.5 g/g creatinine), respectively. The sum of the values of the ratio of measured urinary metabolite concentration to the corresponding ACGIH's biological exposure indices (BEI) [(HA/BEI of HA + MHA/BEI of MHA + MA/BEI of MA)] exceeded 1.0 in 166 (18.4%) workers. Majority of them were from the footwear manufacturing industry (63/129 or 49.2%). Questionnaire interviews were also administered to determine the prevalence of symptoms while at work (acute symptoms) or within the past 6 months (chronic symptoms). Urinary metabolite levels of individual and mixed solvents were compared with the symptoms of all workers. Analysis using Spearman's rank correlation showed in workers whose urinary hippuric acid exceeded 3.75 g/g creatine (1.5 x BEI), significant correlation between their hippuric acid levels and subjective complaints. Workers whose sum of the values of the ratio of measured urinary metabolite concentration to corresponding BEI exceeded 1.5 were selected and comparing this level with their symptoms, significant correlation was also noted in some complaints.

  4. (Liquid + liquid) equilibria for ternary mixtures of (water + propionic acid + organic solvent) at T = 303.2 K

    International Nuclear Information System (INIS)

    Ghanadzadeh, H.; Ghanadzadeh Gilani, A.; Bahrpaima, Kh.; Sariri, R.

    2010-01-01

    Experimental tie-line results and phase diagrams were obtained for the ternary systems of {water + propionic acid + organic solvent (cyclohexane, toluene, and methylcyclohexane)} at T = 303.2 K and atmospheric pressure. The organic solvents were two cycloaliphatic hydrocarbons (i.e., cyclohexane and methylcyclohexane) and an aromatic hydrocarbon (toluene). The experimental tie-lines values were also compared with those calculated by the UNIQUAC and NRTL models. The consistency of the values of the experimental tie-lines was determined through the Othmer-Tobias and Hands plots. Distribution coefficients and separation factors were evaluated over the immiscibility regions and a comparison of the extracting capabilities of the solvents was made with respect to distribution coefficients and separation factors. The Kamlet LSER model was applied to correlate distribution coefficients and separation factors in these ternary systems. The LSER model values showed a good regression to the experimental results.

  5. Alginate Adsorbent Immobilization Technique Promotes Biobutanol Production by Clostridium acetobutylicum Under Extreme Condition of High Concentration of Organic Solvent

    Directory of Open Access Journals (Sweden)

    Zhuoliang Ye

    2018-05-01

    Full Text Available In Acetone-Butanol-Ethanol fermentation, bacteria should tolerate high concentrations of solvent products, which inhibit bacteria growth and limit further increase of solvents to more than 20 g/L. Moreover, this limited solvent concentration significantly increases the cost of solvent separation through traditional approaches. In this study, alginate adsorbent immobilization technique was successfully developed to assist in situ extraction using octanol which is effective in extracting butanol but presents strong toxic effect to bacteria. The adsorbent improved solvent tolerance of Clostridium acetobutylicum under extreme condition of high concentration of organic solvent. Using the developed technique, more than 42% of added bacteria can be adsorbed to the adsorbent. Surface area of the adsorbent was more than 10 times greater than sodium alginate. Scanning electron microscope image shows that an abundant amount of pore structure was successfully developed on adsorbents, promoting bacteria adsorption. In adsorbent assisted ABE fermentation, there was 21.64 g/L butanol in extracting layer compared to negligible butanol produced with only the extractant but without the adsorbent, for the reason that adsorbent can reduce damaging exposure of C. acetobutylicum to octanol. The strategy can improve total butanol production with respect to traditional culture approach by more than 2.5 fold and save energy for subsequent butanol recovery, which effects can potentially make the biobutanol production more economically practical.

  6. The properties of anion-exchange resines in mixtures of organic solvents and water

    International Nuclear Information System (INIS)

    Naveh, J.

    1978-02-01

    The behaviour of anion-exchange resins in water and mixtures of organic solvents and water was studied with special reference to the swelling of the polymer and to the density and enthalpy changes accompanying the swelling. A linear dependence was found between the swelling of dry resin and 1/X (X being the nominal cross-linking percent of the polymer). This dependence is interpreted theoretically. The nominal cross-linking percent,defined by the quantity ratio of the components, is corrected for real cross-linking percent. For the swelling of the resin in dilute aqueous alcohols, a preference for the alcohol was found which is enhanced as the molecular weight of the alcohol increases. Moreover, for certain mole fractions, the preference of the perchlorate form of the resin is greater than that of the chloride form. The temperature dependence of the swelling was measured and the invasion of an electrolyte (LiCl), dissolved in the aqueous-organic phase, into the resine phase was determined. Contrary to what usually happens in pure aqueous phase, where the electrolyte is rejected in accordance with the Donnan law, an almost total invasion of the electrolyte into the resin phase occurs. (author)

  7. Cross-linked poly(tetrahydrofuran) as promising sorbent for organic solvent/oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Yati, Ilker; Ozan Aydin, Gulsah; Bulbul Sonmez, Hayal, E-mail: hayalsonmez@gtu.edu.tr

    2016-05-15

    Highlights: • Poly(tetrahydrofuran) based sorbents were prepared. • PTHF sorbents demonstrate reusability at least for ten times. • PTHF based sorbents show fast and quick absorption-desorption process. • 19 g of oil can be absorbed by 1 g of PTHF based sorbent. - Abstract: In this study, a series of different molecular weights of poly(tetrahydrofuran) (PTHF), which is one of the most important commercial polymers around the world, was condensed with tris[3-(trimethoxysilyl)propyl]isocyanurate (ICS) to generate a cross-linked 3-dimensional network in order to obtain organic solvent/oil sorbents having high swelling capacity. The prepared sorbents show high and fast swelling capacity in oils such as dichloromethane (DCM), tetrahydrofuran (THF), acetone, t-butyl methyl ether (MTBE), gasoline, euro diesel, and crude oil. The recovery of the absorbed oils from contaminated surfaces, especially from water, and the regeneration of the sorbents after several applications are effective. The characterization and thermal properties of the sorbents are identified by Fourier transform infrared spectroscopy (FTIR), solid-state {sup 13}C and {sup 29}Si cross-polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and thermal gravimetric analyses (TGA), respectively. The new usage area of PTHF is emerged by the preparation of PTHF-based network structure with high oil absorption capacity and having excellent reusability as an oil absorbent for the removal of organic liquids from the spill site.

  8. Coordination conversion of cobalt(II) in binary aqueous-organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Khvostova, N.O.; Karapetyan, G.O.; Yanush, O.V.

    1985-11-01

    It has been shown that the thermochromic conversions of cobalt(II) in binary solvents are influenced by a number of factors: the nature of the solvent, the strength of the complexes of octahedral symmetry formed, the outer-sphere influence of the solvent on the complexes, the form of the anion, the solvation of the participants in the reaction, and the interaction of the components of the solvent with one another. A correlation between the strength and the spectral position of the absorption bands of the complexes of the activator has been established, and a spectroscopic criterion for selecting the solvents has been proposed. The expediency of using binary solvents to create effective thermochromic media with variable phototransmission has been substantiated.

  9. Validation of Alternatives to High Volatile Organic Compound Solvents Used in Aeronautical Antifriction Bearing Cleaning

    Science.gov (United States)

    2006-10-17

    982-4832 (fax) tom.torres@navy.mil Quality Assurance Officer Gene Griffin NFESC 1100 23rd Avenue Port Hueneme, CA 93043-4370 (805) 982-2267...solvent replenishment system. The waste solvent shall be captured in a sealed container that is easily acces· sible for periodic disposal. (2) HFE ...Co-Solvent Vapor Degreaser. This method features the use of a hydrocarbon (HC) solvating agent and a Hydrofluoroether ( HFE ) liquid rinse and vapor

  10. COMPARISON OF SORPTION ENERGTICS FOR HYDROPHOBIC ORGANIC CHEMICALS BY SYNTHETIC AND NATURAL SORBENTS FROM METHANOL/WATER SOLVENT MIXTURES

    Science.gov (United States)

    Reversed-phase liquid chromatography (RPLC) was used to investigate the thermodynamics and mechanisms of hydrophobic organic chemical (HOC) retention from methanol/water solvent mixtures. The enthalpy-entropy compensation model was used to infer that the hydro- phobic sorptive me...

  11. Homogeneous solutions of hydrophilic enzymes in nonpolar organic solvents. New systems for fundamental studies and biocatalytic transformations.

    Science.gov (United States)

    Mozhaev, V V; Poltevsky, K G; Slepnev, V I; Badun, G A; Levashov, A V

    1991-11-04

    A typical hydrophilic enzyme, CT, can be dissolved in nonpolar organic solvents (n-octane, cyclohexane and toluene) up to microM concentrations. In the homogeneous solution obtained, the enzyme possesses catalytic activity and enormously high thermostability. It does not lose this activity even after several hours refluxing in octane (126 degrees C) or cyclohexane (81 degrees C).

  12. 40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

    Science.gov (United States)

    2010-07-01

    ... HAP content of aluminum wipedown solvents and aluminum recreational boat surface coatings? 63.5753... Standards for Hazardous Air Pollutants for Boat Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5753 How do I calculate the combined organic HAP content of aluminum...

  13. The use of Nile Red to monitor the aggregation behavior in ternary surfactant-water-organic solvent systems

    NARCIS (Netherlands)

    Stuart, MCA; van de Pas, JC; Engberts, JBFN; Pas, John C. van de

    Ternary systems of surfactants, water and organic solvents were studied by monitoring the steady-state fluorescence of the versatile solvatochromic probe Nile Red. We found not only that Nile Red can be used throughout the whole isotropic regions in the phase diagram, but also that subtle changes in

  14. Nutritional Quality and Physicochemical Characteristics of Defatted Bovine Liver Treated by Supercritical Carbon Dioxide and Organic Solvent

    Science.gov (United States)

    Kang, Sung-Won; Kim, Hye-Min; Rahman, M. Shafiur; Kim, Ah-Na; Yang, Han-Sul

    2017-01-01

    Defatted bovine liver (DBL) is a potential source of protein and minerals. Supercritical carbon dioxide (SC-CO2) and a traditional organic solvent method were used to remove lipid from bovine liver, and the quality characteristics of a control bovine liver (CBL), bovine liver defatted by SC-CO2 (DBLSC-CO2) at different pressures, and bovine liver defatted by organic solvent (DBL-OS) were compared. The DBLSC-CO2 samples had significantly higher (pSC-CO2 than the organic solvent method. SDS-PAGE analysis demonstrated that the CBL and DBLSC-CO2 had protein bands of a similar intensity and area, whereas DBL-OS appeared extremely poor bands or no bands due to the degradation of proteins, particularly in the 50 to 75 kDa and 20 to 25 kDa molecular weight ranges. In addition, DBLSC-CO2 was shown to have superior functional properties in terms of total soluble content, water and oil absorption, and foaming and emulsification properties. Therefore, SC-CO2 treatment offers a nutritionally and environmentally friendly approach for the removal of lipid from high protein food sources. In addition, SC-CO2 may be a better substitute of traditional organic solvent extraction for producing more stable and high quality foods with high-protein, fat-free, and low calorie contents. PMID:28316468

  15. Solvent wash solution

    International Nuclear Information System (INIS)

    Neace, J.C.

    1986-01-01

    This patent describes a process for removing diluent degradation products from a solvent extraction solution comprising an admixture of an organic extractant for uranium and plutonium and a non-polar organic liquid diluent, which has been used to recover uranium and plutonium from spent nuclear fuel. Comprising combining a wash solution consisting of: (a) water; and (b) a positive amount up to about, an including, 50 volume percent of at least one highly-polar water-miscible organic solvent, based on the total volume of the water and the highly-polar organic solvent, with the solvent extraction solution after uranium and plutonium values have been stripped from the solvent extraction solution, the diluent degradation products dissolving in the highly-polar organic solvent and the extractant and diluent of the extraction solution not dissolving in the highly-polar organic solvent, and separating the highly-polar organic solvent and the extraction solution to obtain a purified extraction solution

  16. Organic solvent wetting properties of UV and plasma treated ZnO nanorods: printed electronics approach

    KAUST Repository

    Sliz, Rafal

    2012-09-13

    Due to low manufacturing costs, printed organic solar cells are on the short-list of renewable and environmentally- friendly energy production technologies of the future. However, electrode materials and each photoactive layer require different techniques and approaches. Printing technologies have attracted considerable attention for organic electronics due to their potentially high volume and low cost processing. A case in point is the interface between the substrate and solution (ink) drop, which is a particularly critical issue for printing quality. In addition, methods such as UV, oxygen and argon plasma treatments have proven suitable to increasing the hydrophilicity of treated surfaces. Among several methods of measuring the ink-substrate interface, the simplest and most reliable is the contact angle method. In terms of nanoscale device applications, zinc oxide (ZnO) has gained popularity, owing to its physical and chemical properties. In particular, there is a growing interest in exploiting the unique properties that the so-called nanorod structure exhibits for future 1-dimensional opto-electronic devices. Applications, such as photodiodes, thin-film transistors, sensors and photo anodes in photovoltaic cells have already been demonstrated. This paper presents the wettability properties of ZnO nanorods treated with UV illumination, oxygen and argon plasma for various periods of time. Since this work concentrates on solar cell applications, four of the most common solutions used in organic solar cell manufacture were tested: P3HT:PCBM DCB, P3HT:PCBM CHB, PEDOT:PSS and water. The achieved results prove that different treatments change the contact angle differently. Moreover, solvent behaviour varied uniquely with the applied treatment. © (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  17. The parametars of liver functional status in the wood industry workers exposed to organic solvent volatile compounds

    Directory of Open Access Journals (Sweden)

    S. Sivić

    2005-08-01

    Full Text Available A retrospective-prospective controlled research was conducted in order to determine changes of the liver functionsin the workers exposed to a mixture of organic solvents, whose concentrations did not exceed limits set for the working environment. One hundred and twenty five workers of the„Krivaja“wood factory were involved in this research, 66 of whom had been exposed during their working hours to a mixture of organic solvents for two years and even longer. Average age of workers was 40 +/-15. Another group comprised 59 workers of the same sex, similar age and anthropomorphic characteristics, but they had not been exposed to the mixture of organic solvents (controlled group. The mixture of acetone, xylene, toluene, butyl acetate and isobutanol was found in the air of the working environment. The workers with existing liver diseases, chronic alcoholics, diabetics and those who had recently been exposed to a trauma or surgery, were excluded from the research. The participants’ blood samples were tested for the concentration of aspartate aminotransferase, alanine aminotransferase, total bilirubin, direct bilirubin, total proteins and albumins. The Student’s t-test has shown that there was no significant difference between the controlled and exposed groups for albumin, aminotransferase and bilirubin values, but there was a highly significant difference in the total protein concentrations between thet wogroups.Since there is a correlation between blood concentration and duration of exposure to the mixture of organic solvents, it has been found that correlation coefficient of the bilirubin,aminotransferase and albumin was not significant,however,therewasa considerable positive correlation for total proteins of plasma. Based on the results of the research it could be concludedthat there was no indicative cumulative impact of the mixture of organic solvents to the liver functions.

  18. Elucidation of the structure of organic solutions in solvent extraction by combining molecular dynamics and X-ray scattering

    International Nuclear Information System (INIS)

    Ferru, G.; Gomes Rodrigues, D.; Berthon, L.; Guilbaud, P.; Diat, O.; Bauduin, P.

    2014-01-01

    Knowledge of the supramolecular structure of the organic phase containing amphiphilic ligand molecules is mandatory for full comprehension of ionic separation during solvent extraction. Existing structural models are based on simple geometric aggregates, but no consensus exists on the interaction potentials. Herein, we show that molecular dynamics crossed with scattering techniques offers key insight into the complex fluid involving weak interactions without any long range ordering. Two systems containing mono- or diamide extractants in heptane and contacted with an aqueous phase were selected as examples to demonstrate the advantages of coupling the two approaches for furthering fundamental studies on solvent extraction. (authors)

  19. Radiolytic degradation of octachlorodibenzo-p-dioxin and octachlorodibenzofuran in organic solvents and treatment of dioxin-containing liquid wastes

    International Nuclear Information System (INIS)

    Zhao Changli; Hirota, Koichi; Taguchi, Mitsumasa; Takigami, Machiko; Kojima, Takuji

    2007-01-01

    Degradations of octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) were studied by 60 Co γ-ray in organic solvents: ethanol, n-nonane, and toluene. Both OCDD and OCDF were degraded more efficiently in ethanol than in n-nonane or toluene. The degradation is mainly attributed to electrons and in part to solvent radicals. The addition of ethanol to dioxin-containing liquid wastes enhanced effectively the degradation of dioxins; the liquid wastes did not exhibit the dioxin toxicity at a dose of 100 kGy

  20. Ionization and thermodynamic constants of 6-methylquinoline by potentiometry in aqueous and mixed organic-water solvent systems

    International Nuclear Information System (INIS)

    Hafiz, A; Indhar, B.; Khanzada, A.W.K.

    2000-01-01

    The ionization constant pKa and Gibbs's free energy DG of 6-methylquinoline are determined in aqueous solution at different temperatures and in three mixed organic-water solvent systems at 25 deg. C. It is observed that dissociation constant of 6-methylquinoline in aqueous system decreases with the increase of temperature. The curve is a parabolic. It is noted that pKa values of this compound are higher than those of quinoline and 8-methylquinoline. In case of mixed organic-water solvent systems, the influence of these solvents on the ionization equilibria of NH/sub 2/ group has been observed. The pK M/A and pK T/A values versus percent composition decrease gradually with increase in percent of organic solvents The curve of the pK/sub a/ versus percent composition is a distorted parabola. The data have been obtained potentiometrically by titrating 6-methylquinoline solutions with HCl. The values of dissociation constant were obtained from these data by a computer program written in GW-BASIC. From pKa values Gibbs's free energies DG for the respective pKa values have also been calculated. (author)

  1. Viscosity of binary mixtures of 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid with four organic solvents

    International Nuclear Information System (INIS)

    Ciocirlan, Oana; Croitoru, Oana; Iulian, Olga

    2016-01-01

    Highlights: • Viscosities of four binary mixtures of [Emim][BF4] with organic solvents. • Viscosity models based on Eyring’s theory. • Excess functions calculated. • Data for binaries new in the literature, except for system with DMSO. - Abstract: This paper reports experimental values of dynamic viscosity for four binary systems of 1-ethyl-3-methylimidazolium tetrafluoroborate, [Emim][BF4], with dimethyl sulfoxide (DMSO), acetonitrile (ACN), ethylene glycol (EG) and 1,4-dioxane over the temperature ranges from 293.15 K to 353.15 K at p = 0.1 MPa. All binary mixtures were completely miscible over the entire range of mole fraction, except the system with 1,4-dioxane. The viscosity results have been correlated by the one parameter Grunberg–Nissan and Fang and He equations and the two-parameter McAllister, Eyring-UNIQUAC, Eyring-NRTL and Eyring-Wilson models and the results were compared. Additionally, the viscosity deviations, Δη, and the excess Gibbs energy of activation for viscous flow, G"∗"E, were calculated and fitted to the Redlich–Kister equation. The results show that all Δη values are negative over the whole composition range and the G"∗"E values are positive, except for the system with EG. The results of the excess functions are discussed in terms of molecular interactions.

  2. Monitoring of the aerobe biodegradation of chlorinated organic solvents by stable isotope analysis

    Science.gov (United States)

    Horváth, Anikó; Futó, István; Palcsu, László

    2014-05-01

    Our chemical-biological basic research aims to eliminate chlorinated environmental contaminants from aquifers around industrial areas in the frame of research program supported by the European Social Fund (TÁMOP-4.2.2.A-11/1/KONV-2012-0043). The most careful and simplest way includes the in situ biodegradation with the help of cultured and compound specific strains. Numerous members of Pseudomonas bacteria are famous about function of bioremediation. They can metabolism the environmental hazardous chemicals like gas oils, dyes, and organic solvents. Our research based on the Pseudomonas putida F1 strain, because its ability to degrade halogenated hydrocarbons such as trichloroethylene. Several methods were investigated to estimate the rate of biodegradation, such as the measurement of the concentration of the pollutant along the contamination pathway, the microcosm's studies or the compound specific stable isotope analysis. In this area in the Transcarpathian basin we are pioneers in the stable isotope monitoring of biodegradation. The main goal is to find stable isotope fractionation factors by stable isotope analysis, which can help us to estimate the rate and effectiveness of the biodegradation. The subsequent research period includes the investigation of the method, testing its feasibility and adaptation in the environment. Last but not least, the research gives an opportunity to identify the producer of the contaminant based on the stable isotope composition of the contaminant.

  3. Acute behavioral effects of exposure to some organic solvents -psychophysiological aspects

    Energy Technology Data Exchange (ETDEWEB)

    Winneke, G

    1982-01-01

    Acute low-level exposure to organic solvent vapours may result in prenarcotic states of CNS-depression, often characterized by behavioral dysfunction. Behavioral findings from experimental acute human exposures to toluene, trichloroethylene (TCE), and methylene chloride (MC) are covered in this review. Perceptual measures (e.g. critical flicker fusion . CFF), measures of sustained attention (vigilance), measures of psychomotor performance (as e.g. reaction time, motor speed, coordination) as well as EEG-measures (sensory evoked potentials) are used to illustrate the main effects from such studies. Progressive increase of reaction time was observed at toluene-exposures of only 300 ppm (30 minutes). No consistent behavioral deficit has been reported for trichloroethylene below 300 ppm; instead, visual and auditory evoked potentials were found to be affected at TCE vapour-concentrations between 50 and 100 ppm (3 1/2 - 7 1/2 hours of exposure). CFF-depression, vigilance-decrement and disruption of psychomotor performance has been observed during MC-exposure (200 - 800 ppm; 2-4 hours). Although such behavioral effects are usually considered reversible and of no demonstrated pathological impact, they may nevertheless contribute to accident-prone behavior in occupational settings.

  4. Source profiles of volatile organic compounds associated with solvent use in Beijing, China

    Science.gov (United States)

    Yuan, Bin; Shao, Min; Lu, Sihua; Wang, Bin

    2010-05-01

    Compositions of volatile organic compound (VOC) emissions from painting applications and printing processes were sampled and measured by gas chromatography-mass spectrometry/flame ionization detection (GC-MS/FID) in Beijing. Toluene and C8 aromatics were the most abundant species, accounting for 76% of the total VOCs emitted from paint applications. The major species in printing emissions included heavier alkanes and aromatics, such as n-nonane, n-decane, n-undecane, toluene, and m/p-xylene. Measurements of VOCs obtained from furniture paint emissions in 2003 and 2007 suggest a quick decline in benzene levels associated with formulation changes in furniture paints during these years. A comparison of VOC source profiles for painting and printing between Beijing and other parts of the world showed significant region-specific discrepancies, probably because of different market demands and environmental standards. We conducted the evaluation of the source reactivities for various VOC emission sources. The ozone formation potential (OFP) for unit mass of VOCs source emissions is the highest for paint applications. Substituting solvent-based paints by water-based in Beijing will lead to an OFP reduction of 152,000 tons per year, which is more than 1/4 of the OFPs for VOCs emissions from vehicle exhaust in the city.

  5. The detection of organic solvent vapor by using polymer coated chemocapacitor sensor

    Science.gov (United States)

    Rusdiarna Indrapraja, Apik; Rivai, Muhammad; Arifin, Achmad; Purwanto, Djoko

    2017-05-01

    A chemocapacitor consists of planar interdigital electrodes (IDE) made by two comb electrodes on a substrate. A dielectric film was applied on the electrodes in which the absorbed vapor will modify its permittivity. This study has fabricated chemocapacitor with the IDE distance of 0.5 mm, while the dielectric film was a sensitive layer consisting of a polymeric material. The deposition of the polymeric film was accomplished by drop casting. A sensor array consisting of four chemocapacitors coated with different polymers namely PEG-1540, PEG-20M, PEG-6000, and PVP was used to obtain the pattern of shift in the capacitance. The integrated circuit AD7746 was used as the capacitance to-digital converter (CDC). The organic solvents of ethanol, benzene, and aceton were used as the vapor samples in this experiment. The results showed that the change in the capacitance value increases proportionally to the concentration of vapour where sensors coated with PEG-1540 and PVP have higher sensitivity, i.e. 0.0028pF/part per thousand and 0.0027pF/part per thousand, respectively. Based on the capacitance to digital conversion capabilities, the system provides there solution of 0.4084ppm. The sensor array could produce a different pattern for each of the vapor sample. The Neural Network pattern recognition system could identify the type of vapor automatically with the root mean square error of 10-5

  6. Painting Supramolecular Polymers in Organic Solvents by Super-resolution Microscopy

    Science.gov (United States)

    2018-01-01

    Despite the rapid development of complex functional supramolecular systems, visualization of these architectures under native conditions at high resolution has remained a challenging endeavor. Super-resolution microscopy was recently proposed as an effective tool to unveil one-dimensional nanoscale structures in aqueous media upon chemical functionalization with suitable fluorescent probes. Building upon our previous work, which enabled photoactivation localization microscopy in organic solvents, herein, we present the imaging of one-dimensional supramolecular polymers in their native environment by interface point accumulation for imaging in nanoscale topography (iPAINT). The noncovalent staining, typical of iPAINT, allows the investigation of supramolecular polymers’ structure in situ without any chemical modification. The quasi-permanent adsorption of the dye to the polymer is exploited to identify block-like arrangements within supramolecular fibers, which were obtained upon mixing homopolymers that were prestained with different colors. The staining of the blocks, maintained by the lack of exchange of the dyes, permits the imaging of complex structures for multiple days. This study showcases the potential of PAINT-like strategies such as iPAINT to visualize multicomponent dynamic systems in their native environment with an easy, synthesis-free approach and high spatial resolution. PMID:29697958

  7. Food Simulating Organic Solvents for Evaluating Crosslink Density of Bulk Fill Composite Resin

    Directory of Open Access Journals (Sweden)

    Neveen M. Ayad

    2017-01-01

    Full Text Available Objectives. To evaluate crosslink densities of two bulk fill composite resins and determine if the used Food Simulating Organic Solvent (FSOS affected them. Methods. Forty specimens were prepared from SureFill and SonicFill bulk fill composite resins, 20 each. All specimens were stored dry for 24 h. Each group was divided into 2 subgroups: stored in ethanol (E 75% or in methyl ethyl ketone (MEK 100% for 24 h. Crosslink density was evaluated by calculating the difference between the Vickers hardness numbers of the specimens stored dry and after their storage in FSOS. The data were statistically analyzed using t-test. Results. The means of crosslink density in E and MEK were 6.99% and 9.44% for SureFill and 10.54% and 11.92% for SonicFill, respectively. t-test displayed significant differences between crosslink densities of SureFill and SonicFill: (P<0.0001 in E and (P=0.02 in MEK and between crosslink densities of SureFill in E and MEK (P=0.02. Conclusions. Crosslink density of bulk fill composite resin can be evaluated using E or MEK. SureFill has higher crosslink density than SonicFill in both E and MEK.

  8. Electrochemistry of Simple Organometallic Models of Iron-Iron Hydrogenases in Organic Solvent and Water.

    Science.gov (United States)

    Gloaguen, Frederic

    2016-01-19

    Synthetic models of the active site of iron-iron hydrogenases are currently the subjects of numerous studies aimed at developing H2-production catalysts based on cheap and abundant materials. In this context, the present report offers an electrochemist's view of the catalysis of proton reduction by simple binuclear iron(I) thiolate complexes. Although these complexes probably do not follow a biocatalytic pathway, we analyze and discuss the interplay between the reduction potential and basicity and how these antagonist properties impact the mechanisms of proton-coupled electron transfer to the metal centers. This question is central to any consideration of the activity at the molecular level of hydrogenases and related enzymes. In a second part, special attention is paid to iron thiolate complexes holding rigid and unsaturated bridging ligands. The complexes that enjoy mild reduction potentials and stabilized reduced forms are promising iron-based catalysts for the photodriven evolution of H2 in organic solvents and, more importantly, in water.

  9. Using mixed solvent and changing spin-coating parameters to increase the efficiency and lifetime of organic solar cells.

    Science.gov (United States)

    Tsai, Yu Sheng; Chu, Wei-Ping; Tang, Rong-Ming; Juang, Fuh-Shyang; Chang, Ming-Hua; Liu, Mark O; Hsieh, Tsung-Eong

    2008-10-01

    The derivative of C60, i.e., PCBM, and P3HT (3-hexylthiophene) were dissolved in chloroform:dichlorobenzene mixed solvent, then spin-coated as the active layer for organic solar cells (OSC). The experimental parameters were studied carefully to obtain the optimum power conversion efficiency (PCE), including the solvent mixing ratio, spin-coating speed, annealing conditions for the active layer, etc. The OSC devices were packaged with glass and a newly developed UV-glue to improve the lifetime and PCE. Dichlorobenzene solvent has great effect upon the PCE. Changing the spin-coating speed and increasing the number of steps increased the PCE apparently to 1.4%.

  10. Solvent dependence of organic exciplex fluorescence studied by magnetic effect on reaction yield (M.A.R.Y) spectroscopy

    International Nuclear Information System (INIS)

    Pal, K.

    2011-01-01

    This work aims at understanding the various facets of one of the elementary reactions in nature, the electron transfer reaction using MARY (Magnetic effect on Reaction Yield) spectroscopy as a tool. The prime focus of study by the use this technique was the solvent dependence of organic exciplex fluorescence. Apart from that temperature dependent measurements using MARY spectroscopy have been performed to extract the activation energy parameters of electron transfer reaction. The discovery of magnetic field effect on new system was also a part of our study. The study of solvent dependence of organic exciplex fluorescence using MARY spectroscopy was carried out on the system of 9,10-dimethylanthracene (as the fluorophore) and N,N'-dimethylaniline and 4,4'-Bis(dimethylamino) diphenylmethane (as quenchers) in binary solvent mixtures of toluene/dimethylsulfoxide, benzylacetate/dimethylsulfoxide, toluene/propylenecarbonate and propylacetate/butyronitrile. The work focuses on the use of solvent mixtures rather than pure solvents. The solvent mixtures, tailored to simulate different microenvironemets, were employed to find out the effect of preferential solvation on electron transfer reaction. The contrast in the absolute field effect and linewidth values of the MARY spectra obtained in the four system as a function of dielectric constant scan suggest the imperative effect of concentration fluctuation on the electron transfer reaction. Temperature dependent measurements were performed on the system of N,N,N',N'- tetramethylparaphenylendiamin, photo-ionizing in a mixture of toluene/dimethylsulfoxide. However the sluggish response of the system to temperature changes does not really permit us to extract fruitful results. The magnetic field effect on the much studied system of Perylene/ N.N'-dimethylaniline was discovered for the first time. (author) [de

  11. Long-term occupational exposure to organic solvents affects color vision, contrast sensitivity and visual fields.

    Directory of Open Access Journals (Sweden)

    Thiago Leiros Costa

    Full Text Available The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males and 25 controls with no history of chronic exposure to solvents (10 males. All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6 ± 6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT. Visual field assessment consisted of white-on-white 24-2 automatic perimetry (Humphrey II-750i. Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd. Results from both groups were compared using the Mann-Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01. Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01, and their ellipse area and ellipticity were higher (p<0.01. Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9°, 15° and 21° of eccentricity (p<0.01 and in MD and PSD indexes (p<0.01. Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01 except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05, indexes of the Lanthony D15d (rho=0.52; p<0.05, perimetry results in the fovea (rho= -0.51; p<0.05 and at 3, 9 and 15 degrees of eccentricity (rho= -0.46; p<0.05. Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.

  12. Production of graphene by exfoliation of graphite in a volatile organic solvent

    International Nuclear Information System (INIS)

    Choi, Eun-Young; Choi, Won San; Lee, Young Boo; Noh, Yong-Young

    2011-01-01

    The production of unfunctionalized and nonoxidized graphene by exfoliation of graphite in a volatile solvent, 1-propanol, is reported. A stable homogeneous dispersion of graphene was obtained by mild sonication of graphite powder and subsequent centrifugation. The presence of a graphene monolayer was observed by atomic force microscopy and transmission electron microscopy. The solvent, 1-propanol, from the deposited dispersion was simply and quickly removed by air drying at room temperature, without the help of high temperature annealing or vacuum drying, which shortens production time and does not leave any residue of the solvent in the graphene sheets.

  13. Absorption and emission behaviour of trans- p-coumaric acid in aqueous solutions and some organic solvents

    Science.gov (United States)

    Putschögl, M.; Zirak, P.; Penzkofer, A.

    2008-01-01

    The absorption and fluorescence behaviour of trans- p-coumaric acid ( trans-4-hydroxycinnamic acid) is investigated in buffered aqueous solution over a wide range from pH 1 to pH 12, in un-buffered water, and in some organic solvents. Absorption cross-section spectra, fluorescence quantum distributions, fluorescence quantum yields, and degrees of fluorescence polarisation are measured. p-Coumaric acid exists in different ionic forms in aqueous solution depending on the pH. There is an equilibrium between the neutral form ( p-CAH 2) and the single anionic form ( p-CAH -) at low pH (p Kna ≈ 4.9), and between the single anionic and the double anionic form ( p-CA 2-) at high pH (p Kaa ≈ 9.35). In the organic solvents studied trans- p-coumaric acid is dissolved in its neutral form. The fluorescence quantum yield of trans- p-coumaric acid in aqueous solution is ϕF ≈ 1.4 × 10 -4 for the neutral and the single anionic form, while it is ϕF ≈ 1.3 × 10 -3 for the double anionic form. For trans- p-coumaric acid in organic solvents fluorescence quantum yields in the range from 4.8 × 10 -5 (acetonitrile) to 1.5 × 10 -4 (glycerol) were measured. The fluorescence spectra are 7700-10,000 cm -1 Stokes shifted in aqueous solution, and 5400-8200 cm -1 Stokes shifted in the studied organic solvents. Decay paths responsible for the low fluorescence quantum yields are discussed (photo-isomerisation and internal conversion for p-CA 2-, solvent-assisted intra-molecular charge-transfer or ππ ∗ to nπ ∗ transfer and internal conversion for p-CAH 2 and p-CAH -). The solvent dependence of the first ππ ∗ electronic transition frequency and of the fluorescence Stokes shift of p-CAH 2 is discussed in terms of polar solute-solvent interaction effects. Thereby the ground-state and excite-state molecular dipole moments are extracted.

  14. Absorption and emission behaviour of trans-p-coumaric acid in aqueous solutions and some organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Putschoegl, M.; Zirak, P. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetsstrasse 31, D-93053 Regensburg (Germany); Penzkofer, A. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetsstrasse 31, D-93053 Regensburg (Germany)], E-mail: alfons.penzkofer@physik.uni-regensburg.de

    2008-01-22

    The absorption and fluorescence behaviour of trans-p-coumaric acid (trans-4-hydroxycinnamic acid) is investigated in buffered aqueous solution over a wide range from pH 1 to pH 12, in un-buffered water, and in some organic solvents. Absorption cross-section spectra, fluorescence quantum distributions, fluorescence quantum yields, and degrees of fluorescence polarisation are measured. p-Coumaric acid exists in different ionic forms in aqueous solution depending on the pH. There is an equilibrium between the neutral form (p-CAH{sub 2}) and the single anionic form (p-CAH{sup -}) at low pH (pK{sub na} {approx} 4.9), and between the single anionic and the double anionic form (p-CA{sup 2-}) at high pH (pK{sub aa} {approx} 9.35). In the organic solvents studied trans-p-coumaric acid is dissolved in its neutral form. The fluorescence quantum yield of trans-p-coumaric acid in aqueous solution is {phi}{sub F} {approx} 1.4 x 10{sup -4} for the neutral and the single anionic form, while it is {phi}{sub F} {approx} 1.3 x 10{sup -3} for the double anionic form. For trans-p-coumaric acid in organic solvents fluorescence quantum yields in the range from 4.8 x 10{sup -5} (acetonitrile) to 1.5 x 10{sup -4} (glycerol) were measured. The fluorescence spectra are 7700-10,000 cm{sup -1} Stokes shifted in aqueous solution, and 5400-8200 cm{sup -1} Stokes shifted in the studied organic solvents. Decay paths responsible for the low fluorescence quantum yields are discussed (photo-isomerisation and internal conversion for p-CA{sup 2-}, solvent-assisted intra-molecular charge-transfer or {pi}{pi}* to n{pi}* transfer and internal conversion for p-CAH{sub 2} and p-CAH{sup -}). The solvent dependence of the first {pi}{pi}* electronic transition frequency and of the fluorescence Stokes shift of p-CAH{sub 2} is discussed in terms of polar solute-solvent interaction effects. Thereby the ground-state and excite-state molecular dipole moments are extracted.

  15. Absorption and emission behaviour of trans-p-coumaric acid in aqueous solutions and some organic solvents

    International Nuclear Information System (INIS)

    Putschoegl, M.; Zirak, P.; Penzkofer, A.

    2008-01-01

    The absorption and fluorescence behaviour of trans-p-coumaric acid (trans-4-hydroxycinnamic acid) is investigated in buffered aqueous solution over a wide range from pH 1 to pH 12, in un-buffered water, and in some organic solvents. Absorption cross-section spectra, fluorescence quantum distributions, fluorescence quantum yields, and degrees of fluorescence polarisation are measured. p-Coumaric acid exists in different ionic forms in aqueous solution depending on the pH. There is an equilibrium between the neutral form (p-CAH 2 ) and the single anionic form (p-CAH - ) at low pH (pK na ∼ 4.9), and between the single anionic and the double anionic form (p-CA 2- ) at high pH (pK aa ∼ 9.35). In the organic solvents studied trans-p-coumaric acid is dissolved in its neutral form. The fluorescence quantum yield of trans-p-coumaric acid in aqueous solution is φ F ∼ 1.4 x 10 -4 for the neutral and the single anionic form, while it is φ F ∼ 1.3 x 10 -3 for the double anionic form. For trans-p-coumaric acid in organic solvents fluorescence quantum yields in the range from 4.8 x 10 -5 (acetonitrile) to 1.5 x 10 -4 (glycerol) were measured. The fluorescence spectra are 7700-10,000 cm -1 Stokes shifted in aqueous solution, and 5400-8200 cm -1 Stokes shifted in the studied organic solvents. Decay paths responsible for the low fluorescence quantum yields are discussed (photo-isomerisation and internal conversion for p-CA 2- , solvent-assisted intra-molecular charge-transfer or ππ* to nπ* transfer and internal conversion for p-CAH 2 and p-CAH - ). The solvent dependence of the first ππ* electronic transition frequency and of the fluorescence Stokes shift of p-CAH 2 is discussed in terms of polar solute-solvent interaction effects. Thereby the ground-state and excite-state molecular dipole moments are extracted

  16. Nanofiltration and granular activated carbon treatment of perfluoroalkyl acids.

    Science.gov (United States)

    Appleman, Timothy D; Dickenson, Eric R V; Bellona, Christopher; Higgins, Christopher P

    2013-09-15

    Perfluoroalkyl acids (PFAAs) are of concern because of their persistence in the environment and the potential toxicological effects on humans exposed to PFAAs through a variety of possible exposure routes, including contaminated drinking water. This study evaluated the efficacy of nanofiltration (NF) and granular activated carbon (GAC) adsorption in removing a suite of PFAAs from water. Virgin flat-sheet NF membranes (NF270, Dow/Filmtec) were tested at permeate fluxes of 17-75 Lm(-2)h(-1) using deionized (DI) water and artificial groundwater. The effects of membrane fouling by humic acid on PFAA rejection were also tested under constant permeate flux conditions. Both virgin and fouled NF270 membranes demonstrated >93% removal for all PFAAs under all conditions tested. GAC efficacy was tested using rapid small-scale columns packed with Calgon Filtrasorb300 (F300) carbon and DI water with and without dissolved organic matter (DOM). DOM effects were also evaluated with F600 and Siemens AquaCarb1240C. The F300 GAC had 20% breakthrough of all PFAAs by 10,000 BVs was observed for all carbons. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. The effect of wastewater pretreatment on nanofiltration membrane performance

    Directory of Open Access Journals (Sweden)

    Ali Hashlamon

    2017-03-01

    Full Text Available Membrane fouling is considered a serious obstacle for operation and cost efficiency in wastewater treatment using nanofiltration (NF. However, pretreatment is the most practical way to reduce this prior to NF. In this research, two types of wastewaters were pretreated with different methods prior to NF to examine the effect of pretreatment on membrane fouling in terms of turbidity, chemical oxygen demand (COD and permeate flux. Turbidity and COD were measured to assess solid foulants and organic species in the wastewater, respectively. The first sample was secondary treated sewage, which was pretreated using coagulation-flocculation-sedimentation (CFS only. Steady flux was increased from 24 L/m2h for wastewater without pretreatment to 32.1 L/m2h with pretreatment. COD was also eliminated after CFS/NF, and turbidity was reduced to 0.6 NTU. The second sample was diluted biodiesel wastewater, which was pretreated using a combination of powdered-activated carbon (PAC adsorption and CFS (PAC/CFS. Steady flux was increased from 22.3 L/m2h for wastewater without pretreatment to 28.7 L/m2h with pretreatment; biodiesel wastewater quality also improved. Turbidity was reduced from 12 to 0.6 NTU, and COD was reduced from 526 to 4 mg/L after NF with PAC/CFS pretreatment, while COD was reduced from 526 to 95 mg/L using NF without pretreatment.

  18. Nanofiltration technology in water treatment and reuse: applications and costs.

    Science.gov (United States)

    Shahmansouri, Arash; Bellona, Christopher

    2015-01-01

    Nanofiltration (NF) is a relatively recent development in membrane technology with characteristics that fall between ultrafiltration and reverse osmosis (RO). While RO membranes dominate the seawater desalination industry, NF is employed in a variety of water and wastewater treatment and industrial applications for the selective removal of ions and organic substances, as well as certain niche seawater desalination applications. The purpose of this study was to review the application of NF membranes in the water and wastewater industry including water softening and color removal, industrial wastewater treatment, water reuse, and desalination. Basic economic analyses were also performed to compare the profitability of using NF membranes over alternative processes. Although any detailed cost estimation is hampered by some uncertainty (e.g. applicability of estimation methods to large-scale systems, labor costs in different areas of the world), NF was found to be a cost-effective technology for certain investigated applications. The selection of NF over other treatment technologies, however, is dependent on several factors including pretreatment requirements, influent water quality, treatment facility capacity, and treatment goals.

  19. The effect of organic solvent, temperature and mixing time on the production of oil from Moringa oleifera seeds

    Science.gov (United States)

    Ghazali, Q.; Yasin, N. H. M.

    2016-06-01

    The effect of three different organic solvent, temperature and mixing time on the production of oil from M.oleifera seeds were studied to evaluate the effectiveness in obtaining the high oil yield based on the percentage of oil production. The modified version of Soxhlet extraction method was carried out to extract the oil from M.oleifera seeds by using hexane, heptane and ethanol as the organic solvent. Among the three solvents, it is found that heptane yield higher oil from M.oleifera seeds with maximum oil yield of 36.37% was obtained followed by hexane and ethanol with 33.89% and 18.46%, respectively. By using heptane as a solvent, the temperature (60oC, 70oC, 80oC) and mixing time (6 h, 7 h, and 8 h) were investigated to ensure the high oil yield over the experimental ranges employed and high oil yield was obtained at 600C for 6 h with percentage oil yield of 36.37%. The fatty acid compositions of M.oleifera seeds oil were analyzed using Gas Chromatography/Mass Spectrometry (GC-MS). The main components of fatty acid contained in the oil extracted from M.oleifera seeds was oleic acid, followed by palmitic acid and arachidic acid, and small amount of behenic acid and margaric acid.

  20. Biological treatment and nanofiltration of denim textile wastewater for reuse

    International Nuclear Information System (INIS)

    Sahinkaya, Erkan; Uzal, Nigmet; Yetis, Ulku; Dilek, Filiz B.

    2008-01-01

    This study aims at coupling of activated sludge treatment with nanofiltration to improve denim textile wastewater quality to reuse criteria. In the activated sludge reactor, the COD removal efficiency was quite high as it was 91 ± 2% and 84 ± 4% on the basis of total and soluble feed COD, respectively. The color removal efficiency was 75 ± 10%, and around 50-70% of removed color was adsorbed on biomass or precipitated within the reactor. The high conductivity of the wastewater, as high as 8 mS/cm, did not adversely affect system performance. Although biological treatment is quite efficient, the wastewater does not meet the reuse criteria. Hence, further treatment to improve treated water quality was investigated using nanofiltration. Dead-end microfiltration (MF) with 5 μm pore size was applied to remove coarse particles before nanofiltration. The color rejection of nanofiltration was almost complete and permeate color was always lower than 10 Pt-Co. Similarly, quite high rejections were observed for COD (80-100%). Permeate conductivity was between 1.98 and 2.67 mS/cm (65% conductivity rejection). Wastewater fluxes were between 31 and 37 L/m 2 /h at 5.07 bars corresponding to around 45% flux declines compared to clean water fluxes. In conclusion, for denim textile wastewaters nanofiltration after biological treatment can be applied to meet reuse criteria

  1. Self-Assembly of Block and Graft Copolymers in Organic Solvents: An Overview of Recent Advances

    Directory of Open Access Journals (Sweden)

    Leonard Ionut Atanase

    2018-01-01

    Full Text Available This review is an attempt to update the recent advances in the self-assembly of amphiphilic block and graft copolymers. Their micellization behavior is highlighted for linear AB, ABC triblock terpolymers, and graft structures in non-aqueous selective polar and non-polar solvents, including solvent mixtures and ionic liquids. The micellar characteristics, such as particle size, aggregation number, and morphology, are examined as a function of the copolymers’ architecture and molecular characteristics.

  2. Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

    International Nuclear Information System (INIS)

    Asim, Sadia; Mansha, Asim; Grampp, Günter; Landgraf, Stephan; Zahid, Muhammad; Bhatti, Ijaz Ahmad

    2014-01-01

    Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε s ≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv 0 / ), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν ν ) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G ET = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair or solvent separated

  3. Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Asim, Sadia [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Mansha, Asim [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry, Government College University, Faisalabad (Pakistan); Grampp, Günter, E-mail: grampp@tugraz.at [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Landgraf, Stephan [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Zahid, Muhammad [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Bhatti, Ijaz Ahmad [Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan)

    2014-09-15

    Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε{sub s}≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv{sub 0}{sup /}), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν{sub ν}) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G{sub ET} = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair

  4. Kerogen chemistry 5. Anhydride formation in, solvent swelling of, and loss of organics on demineralization of Kimmeridge shales

    International Nuclear Information System (INIS)

    Larsen, John W.; Flores, Carlos Islas

    2008-01-01

    The results of three short and related, but experimentally independent, studies of 4 Kimmeridge shales and their kerogens are reported. Differential scanning calorimeter (DSC) studies of the kerogens reveal that three of the four show evidence of anhydride formation when heated at 20 C/min between 50 C and 180 C. There is no regular rank dependence of anhydride formation. After solvent swelling in tetrahydrofuran (THF), extracted organics were isolated from the THF and the recovered kerogens were swollen a second time in fresh THF. The second solvent swelling ratios were slightly larger than the first because the presence of the extracts in the original THF lowers solvent activity thus reducing swelling. The shales were demineralized in the usual way except that methylene chloride was added to dissolve any organics that were liberated from the rock as a consequence of mineral dissolution. Small amounts of organics were found in the methylene chloride supporting Price and Clayton's conclusion that organics are expelled from the kerogen and are present in lacunae in the minerals. (author)

  5. Ozonation of nanofiltration permeate of whey before processing by reverse osmosis

    Directory of Open Access Journals (Sweden)

    Zmievskii Yurii G.

    2017-01-01

    Full Text Available During nanofiltration processing of whey a significant amount of permeate is generated. In some cases this permeate is treated by reverse osmosis to get purified water for technological needs. Dry substances are not used, because they contain practically the same amount of organic and inorganic components. Mineral substances can be used for the mineralization of drinking water purified by reverse osmosis. However, the presence of organic compounds complicates the process of separation, as well as reduces the specific productivity of reverse osmosis membranes at the concentration stage. Therefore, the search for methods of destruction and removal of organic components is grounded. In the presented work, experimental studies of ozonation and sorption of organic compounds by activated carbon were carried. It has been shown that ozonation improves the degree of sorption purification by six times. Sequential treatment with ozone and subsequent filtration through the layer of activated carbon improves the specific productivity of reverse osmosis membranes by 30% at the stage of treatment of the nanofiltration permeate, while their selectivity remains unchanged.

  6. Parental Occupational Exposure to Organic Solvents and Testicular Germ Cell Tumors in their Offspring: NORD-TEST Study.

    Science.gov (United States)

    Le Cornet, Charlotte; Fervers, Béatrice; Pukkala, Eero; Tynes, Tore; Feychting, Maria; Hansen, Johnni; Togawa, Kayo; Nordby, Karl-Christian; Oksbjerg Dalton, Susanne; Uuksulainen, Sanni; Wiebert, Pernilla; Woldbæk, Torill; Skakkebæk, Niels E; Olsson, Ann; Schüz, Joachim

    2017-06-30

    Testicular germ cell tumors (TGCT) were suggested to have a prenatal environmentally related origin. The potential endocrine disrupting properties of certain solvents may interfere with the male genital development in utero . We aimed to assess the association between maternal and paternal occupational exposures to organic solvents during the prenatal period and TGCT risk in their offspring. This registry-based case control study included TGCT cases aged 14–49 y ( n =8,112) diagnosed from 1978 to 2012 in Finland, Norway, and Sweden. Controls ( n =26,264) were randomly selected from the central population registries and were individually matched to cases on year and country of birth. Occupational histories of parents prior to the child’s birth were extracted from the national censuses. Job codes were converted into solvent exposure using the Nordic job-Nordic Occupational Cancer Study Job-Exposure Matrix. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). Overall, no association was found between prenatal maternal exposure to solvents and TGCT risk. In subset analyses using only mothers for whom occupational information was available in the year of or in the year prior to the child’s birth, there was an association with maternal exposure to aromatic hydrocarbon solvents (ARHC) (OR=1.53; CI: 1.08, 2.17), driven by exposure to toluene (OR=1.67; CI: 1.02, 2.73). No association was seen for any paternal occupational exposure to solvents with the exception of exposure to perchloroethylene in Finland (OR=2.42; CI: 1.32, 4.41). This study suggests a modest increase in TGCT risk associated with maternal prenatal exposure to ARHC. https://doi.org/10.1289/EHP864.

  7. PAHs concentration and toxicity in organic solvent extracts of atmospheric particulate matter and sea sediments.

    Science.gov (United States)

    Ozaki, Noriatsu; Takeuchi, Shin-ya; Kojima, Keisuke; Kindaichi, Tomonori; Komatsu, Toshiko; Fukushima, Takehiko

    2012-01-01

    The concentration of polycyclic aromatic hydrocarbons (PAHs) and the toxicity to marine bacteria (Vibrio fischeri) were measured for the organic solvent extracts of sea sediments collected from an urban watershed area (Hiroshima Bay) of Japan and compared with the concentrations and toxicity of atmospheric particulate matter (PM). In atmospheric PM, the PAHs concentration was highest in fine particulate matter (FPM) collected during cold seasons. The concentrations of sea sediments were 0.01-0.001 times those of atmospheric PM. 1/EC50 was 1-10 L g(-1) PM for atmospheric PM and 0.1-1 L g(-1) dry solids for sea sediments. These results imply that toxic substances from atmospheric PM are diluted several tens or hundreds of times in sea sediments. The ratio of the 1/EC50 to PAHs concentration ((1/EC50)/16PAHs) was stable for all sea sediments (0.1-1 L μg(-1) 16PAHs) and was the same order of magnitude as that of FPM and coarse particulate matter (CPM). The ratio of sediments collected from the west was more similar to that of CPM while that from the east was more similar to FPM, possibly because of hydraulic differences among water bodies. The PAHs concentration pattern analyses (principal component analysis and isomer ratio analysis) were conducted and the results showed that the PAHs pattern in sea sediments was quite different to that of FPM and CPM. Comparison with previously conducted PAHs analyses suggested that biomass burning residues comprised a major portion of these other sources.

  8. Solvent-free directed patterning of a highly ordered liquid crystalline organic semiconductor via template-assisted self-assembly for organic transistors.

    Science.gov (United States)

    Kim, Aryeon; Jang, Kwang-Suk; Kim, Jinsoo; Won, Jong Chan; Yi, Mi Hye; Kim, Hanim; Yoon, Dong Ki; Shin, Tae Joo; Lee, Myong-Hoon; Ka, Jae-Won; Kim, Yun Ho

    2013-11-20

    Highly ordered organic semiconductor micropatterns of the liquid-crystalline small molecule 2,7-didecylbenzothienobenzothiophene (C10 -BTBT) are fabricated using a simple method based on template-assisted self-assembly (TASA). The liquid crystallinity of C10 -BTBT allows solvent-free fabrication of high-performance printed organic field-effect transistors (OFETs). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Degradation of lipids in yeast (Saccharomyces cerevisiae) at the early phase of organic solvent-induced autolysis

    International Nuclear Information System (INIS)

    Ishida-Ichimasa, Michiko

    1978-01-01

    Initial stage of organic solvent-induced autolysis in yeast was studied with 14 C-acetate labeled cells. In the case of toluene-induced autolysis, primary cell injury which was estimated by leakage of UV absorbing substances from cell accompanied rapid deacylation of phospholipids. Lysophospholipids did not occur during autolysis. When autolysis was induced by addition of ethyl acetate, phospholipids of yeast cells were not degraded so much. Ethyl acetate rather inhibited yeast phospholipase activity under the condition tested. (auth.)

  10. Composition of oleoresins from two kinds of chili pepper (habanero and tabasco) obtained by lixiviation with organic solvents

    OpenAIRE

    Restrepo Gallego, Mauricio; Llanos Ríos, Natalia; Fonseca Echeverri, Carlos Enrique

    2007-01-01

    Introduction. In the development of new processes and ingredients for food industry, extraction techniques allow us to obtain active principles from natural products, good for human consuming and strongly related to the tendency towards a healthier and free of contaminants feeding. Oleoresins from vegetables allow us to work with dye and aromatic components (as in the case of peppers, for which, extraction with organic solvents is a common practice that must be refi...

  11. [Characterization of severe acute occupational poisoning accidents related to organic solvents in China between 1989 and 2003].

    Science.gov (United States)

    Wang, Huan-Qiang; Li, Tao; Zhang, Min; Wang, Hong-Fei; Chen, Shu-Yang; Du, Xie-Yi; Wang, Dan; Zhang, Shuang; Qin, Jian

    2006-12-01

    To analyze severe acute occupational poisoning accidents related to organic solvents reported in China between 1989 and 2003, and to study the characteristics of severe acute occupational poisoning accidents and provide scientific evidences for prevention and control strategies. The data from the national occupational poisoning case reporting system were analyzed with descriptive methods. (1) There were 58 severe acute occupational poisoning accidents related to organic solvents for 15 years with 393 workers poisoned and 48 workers died. The total poisoning rate was 51.2%, and the total mortality was 12.2%. The average poisoning age was (30.9 +/- 8.8) years old and the average death age was (30.6 +/- 12.0) years old. (2) There were 11 types of chemicals that caused these poisoning accidents, and most of the accidents were caused by benzene and homologs. (3) Most of the accidents occurred in manufacture, chemical industry, construction industry, transportation and storage industry, service and commerce. The risk was higher in some jobs than in others, such as paint spraying and cleanout. The poisoning accidents occurred more frequently from April to July each year. (4) The main causes of the accidents were poor ventilation (23.6%), lack of personal protection equipment (21.2%), lack of safety education (19.2%), and lack of safety work practice (15.8%) etc. The ventilation at the workplace involved in organic solvents should be maintained and the skin contacting directly with the organic solvents should be avoided, and it is encouraged to replace the poison with the nontoxic or lower toxic chemicals.

  12. Biotransformation of citrinin to decarboxycitrinin using an organic solvent-tolerant marine bacterium, Moraxella sp. (MB1)

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Naik, C.G.; Rodrigues, C.

    and Bhosle, 2003), are reported to grow in media containing various amounts of organic solvents (cyclohexane, p-xylene, 1-octanol, toluene, 1-heptanol, benzene etc.). These bacteria have mechanisms available to cope with the deleterious effects..., when compared to their chemical counterparts, offer the advantages of high selectivity and mild operating conditions. For example esterases are being increasingly recognized as useful for stereospecific manipulation of esters (Cornec et al., 1998...

  13. ``Living polymers'' in organic solvents : stress relaxation in bicopper tetracarboxylate/tert-butyl cyclohexane solutions

    Science.gov (United States)

    Terech, P.; Maldivi, P.; Dammer, C.

    1994-10-01

    Viscoelastic solutions of a bicopper tetracarboxylate complex in tert-butylcyclohexane have been studied by dynamic rheology in a wide range of concentrations (0.5-1.5 % volume fraction). The zero shear viscosity, the elastic modulus, the terminal stress relaxation time and the height of the high-frequency dip, in a Cole-Cole representation of the complex elastic modulus, follow scaling laws. The related exponents are discussed in the context of the physics of “living polymers” : a term used to describe worm-like species undergoing scission/recombination reactions competing mainly with the reptation motions of the chains. The current system, made up of molecular threads (17.5 Å diameter) of Cu2(O2C-CH(C2H5)C4H9)4 in the apolar solvent, is representative of a “living polymer” where, instead of mechanisms involving transient star polymeric crosslinks, a reversible scission mechanism prevails. The dynamics in the high-frequency range evolves from a regime where reptation is the dominant relaxation mechanism to a cross-over regime where “breathing” fluctuations and Rouse motions become important. Large modifications of the stress relaxation function occur for more concentrated systems. The binary system is the first example of a “living polymer” in an organic solvent and exhibits elastic moduli (G ≈ ca. 120 Pa à φ = 1 %) which are at least 20 times larger than those found for the aqueous “living polymer” systems. Les solutions viscoélastiques d'un tétracarboxylate binucléaire de cuivre dans le tert-butylcyclohexane sont étudiées par rhéologie en mode dynamique dans une gamme étendue de concentrations (0,5 %-15,5 %). La viscosité à gradient nul, le module élastique, le temps terminal de relaxation et la hauteur du puits à haute fréquence, dans une représentation Cole-Cole du module élastique complexe, suivent des lois d'échelles. Les exposants correspondants sont discutés dans le contexte de la physique des “polymères vivants

  14. Sample loading for C-14 measurement in the simulated organic solvent waste from a CANDU Nuclear Power Plant

    International Nuclear Information System (INIS)

    Dianu, Magdalena; Podina, C.; Nita, Valentina

    2005-01-01

    Full text: Sample preparation is a critical step in obtaining accurate results in scintillation counting. Standard (22 ml) glass and plastic vials were used in these experiments. The preliminary research was conducted using glass vials to allow visual verification that a homogeneous solution is obtained at the desired cocktail/sample ratio. Then, the research was moved into plastic vials to reduce backgrounds and improve the counting rate. Samples were counted in a Model 2100 TR Packard TRI-CARB liquid scintillation analyzer. The paper mainly contains: - Composition and data about liquid scintillation cocktails used (tables); - Characterization of radioactive waste - organic solvent contaminated with C-14; - Sample loading (tables); - Efficiency vs Sample Loading - for each cocktail used. Organic solvent sample volumes were added to the vials in 0.5 ml increments from 1 ml to 2 ml. Then, the liquid scintillation cocktail was added so that the sample-cocktail volume was 20 ml. Each vial was shaken vigorously for several seconds after each addition to ensure homogeneity and count. Blank vials were prepared using C-14-free organic solvent samples in the same sample-cocktail proportions. After at least two hours, the samples and blank vials were counted for ten minutes, using a Packard counter. (authors)

  15. Separation properties of aluminium-plastic laminates in post-consumer Tetra Pak with mixed organic solvent.

    Science.gov (United States)

    Zhang, S F; Zhang, L L; Luo, K; Sun, Z X; Mei, X X

    2014-04-01

    The separation properties of the aluminium-plastic laminates in postconsumer Tetra Pak structure were studied in this present work. The organic solvent blend of benzene-ethyl alcohol-water was used as the separation reagent. Then triangle coordinate figure analysis was taken to optimize the volume proportion of various components in the separating agent and separation process. And the separation temperature of aluminium-plastic laminates was determined by the separation time, efficiency, and total mass loss of products. The results show that cost-efficient separations perform best with low usage of solvents at certain temperatures, for certain times, and within a certain range of volume proportions of the three components in the solvent agent. It is also found that similar solubility parameters of solvents and polyethylene adhesives (range 26.06-34.85) are a key factor for the separation of the aluminium-plastic laminates. Such multisolvent processes based on the combined-system concept will be vital to applications in the recycling industry.

  16. Removal of uranium from ammonium nitrate solution by nanofiltration

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Runci; Yuan, Zhongwei; Yan, Taihong; Zheng, Weifang [China Institute of Atomic Energy, Beijing (China). Dept. of Radiochemistry

    2017-07-01

    Two types of nanofiltration membranes were tested to remove uranium dissolved in ammonium nitrate solution, and the influence of operating parameters as transmembrane pressure, tangential velocity and feed temperature was investigated. Experimental results showed NF270 membrane can reject more than 96% uranium and allow most (90% min) ammonium nitrate solution passed by, and with a permeate flux of 60 L/(m{sup 2}.h). Nanofiltration seems to be a promising technology for the removal of uranium and recovery of ammonium nitrate simultaneously.

  17. A review of potential neurotoxic mechanisms among three chlorinated organic solvents

    International Nuclear Information System (INIS)

    Bale, Ambuja S.; Barone, Stan; Scott, Cheryl Siegel; Cooper, Glinda S.

    2011-01-01

    The potential for central nervous system depressant effects from three widely used chlorinated solvents, trichloroethylene (TCE), perchloroethylene (PERC), and dichloromethane (DCM), has been shown in human and animal studies. Commonalities of neurobehavioral and neurophysiological changes for the chlorinated solvents in in vivo studies suggest that there is a common mechanism(s) of action in producing resultant neurotoxicological consequences. The purpose of this review is to examine the mechanistic studies conducted with these chlorinated solvents and to propose potential mechanisms of action for the different neurological effects observed. Mechanistic studies indicate that this solvent class has several molecular targets in the brain. Additionally, there are several pieces of evidence from animal studies indicating this solvent class alters neurochemical functions in the brain. Although earlier evidence indicated that these three chlorinated solvents perturb the lipid bilayer, more recent data suggest an interaction between several specific neuronal receptors produces the resultant neurobehavioral effects. Collectively, TCE, PERC, and DCM have been reported to interact directly with several different classes of neuronal receptors by generally inhibiting excitatory receptors/channels and potentiating the function of inhibitory receptors/channels. Given this mechanistic information and available studies for TCE, DCM, and PERC, we provide hypotheses on primary targets (e.g. ion channel targets) that appear to be most influential in producing the resultant neurological effects. - Research highlights: → Comparison of neurological effects among TCE, PERC, and DCM. → Correlation of mechanistic findings to neurological effects. → Data support that TCE, PERC, and DCM interact with several ion channels to produce neurological changes.

  18. Parental Occupational Exposure to Organic Solvents and Testicular Germ Cell Tumors in their Offspring

    DEFF Research Database (Denmark)

    Le Cornet, Charlotte; Fervers, Béatrice; Pukkala, Eero

    2017-01-01

    BACKGROUND: Testicular germ cell tumors (TGCT) were suggested to have a prenatal environmentally related origin. The potential endocrine disrupting properties of certain solvents may interfere with the male genital development in utero. OBJECTIVES: We aimed to assess the association between......-Nordic Occupational Cancer Study Job-Exposure Matrix. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Overall, no association was found between prenatal maternal exposure to solvents and TGCT risk. In subset analyses using only mothers for whom...

  19. Voltammetric Studies on Vitamins D2 and D3 in Organic Solvents

    International Nuclear Information System (INIS)

    Chan, Ya Yun; Yue, Yanni; Webster, Richard D.

    2014-01-01

    Highlights: • Vitamins D 2 and D 3 undergo a chemically irreversible oxidation process. • The electrochemical oxidation occurs via one-electron on short (CV) time-scales. • On long time scales (electrolysis) the oxidation occurs via two-electrons. • Chemical oxidation was performed using two molar equivalents of NO + . • Oxidation occurs at the triene moiety. - Abstract: The electrochemical behavior of vitamins D 2 and D 3 were examined by performing cyclic voltammetry (CV), rotating disk electrode voltammetry, controlled potential electrolysis and chemical oxidation in aprotic organic solvents. Both vitamins were electrochemically oxidized in dichloromethane and acetonitrile (E p ox ∼ +0.8 vs. (Fc/Fc + )/V, where E p ox is the anodic peak potential and Fc = ferrocene) via a one-electron chemically irreversible process on the short voltammetric time scale (≤ seconds). Varying the scan rate (0.1 V s −1 to 20 V s −1 ) and temperature (233 K to 293 K) did not strongly affect the voltammetric response recorded on platinum and glassy carbon electrode surfaces with the oxidation process remaining chemically irreversible over the range of scan rates and temperatures tested, indicating that the initially formed cation radical was not long-lived. Repetitive CV experiments indicated that the oxidized product partially adsorbed onto the electrode surface, resulting in diminishing peak currents with multiple scans. Bulk controlled potential electrolysis of the vitamin D compounds performed by alternating several cycles of oxidative electrolysis and reductive pulsed stripping proved to be effective in stripping the adsorbed species off the electrode surfaces. Longer time scale bulk electrolysis experiments led to the detection of a new oxidation peak appearing at less positive potentials as the electrolysis progressed, suggesting that the compounds underwent oxidation on long time scales (minutes to hours) via a two electron process. The vitamins were most

  20. Solvent substitutes

    International Nuclear Information System (INIS)

    Evanoff, S.P.

    1995-01-01

    The environmental and industrial hygiene regulations promulgated since 1980, most notably the Superfund Amendments and Reauthorization Act (SARA), the Hazardous and Solid Waste Amendments to the Resources Conservation and Recovery Act (RCRA), and the Clean Air Act Amendments of 1990, have brought about an increased emphasis on user exposure, hazardous waste generation, and air emissions. As a result, industry is performing a fundamental reassessment of cleaning solvents, processes, and procedures. The more progressive organizations have made their goal the elimination of solvents that may pose significant potential human health and environmental hazards. This chapter discusses solvent cleaning in metal-finishing, metal-manufacturing, and industrial maintenance applications; precision cleaning; and electronics manufacturing. Nonmetallic cleaning, adhesives, coatings, inks, and aerosols also will be addressed, but in a more cursory manner

  1. Predicting the Disorder–Order Transition of Solvent-Free Nanoparticle–Organic Hybrid Materials

    KAUST Repository

    Yu, Hsiu-Yu; Koch, Donald L.

    2013-01-01

    in the ordered phase, the cooperation of the oligomers in filling the space is hindered. Therefore, shorter oligomers feel a stronger entropic penalty in the ordered solid and favor the disordered phase. Strikingly, we found that the solvent-free system has a

  2. Solvents in Organic Synthesis: Replacement and Multi-step Reaction Systems

    DEFF Research Database (Denmark)

    Gani, Rafiqul; Gómez, Paola Arenas; Folic, Milica

    2008-01-01

    Solvents are widely used as reaction media in the chemical, fine chemical and pharmaceutical industries, but they present numerous environmental, health and safety (EHS) challenges that need to be managed and are subject to increasing regulatory scrutiny. The above issues, together with the princ...

  3. Novel Paradigm Supercapacitors V: Significance of Organic Polar Solvents and Salt Identities

    Science.gov (United States)

    2017-06-01

    146 E. DISCUSSION OF VARIABLES ..........................................................146 1. Viscosity and Density...146 Table 77. Kinematic Viscosity and Density of Water and Tested Solvents...surface area per unit mass, or unit volume [22]. Examples of this material include carbon, conductive clays , some metal and oxides and graphene. These

  4. Long-Term Stability of Polymer-Coated Surface Transverse Wave Sensors for the Detection of Organic Solvent Vapors.

    Science.gov (United States)

    Stahl, Ullrich; Voigt, Achim; Dirschka, Marian; Barié, Nicole; Richter, Christiane; Waldbaur, Ansgar; Gruhl, Friederike J; Rapp, Bastian E; Rapp, Michael; Länge, Kerstin

    2017-11-03

    Arrays with polymer-coated acoustic sensors, such as surface acoustic wave (SAW) and surface transverse wave (STW) sensors, have successfully been applied for a variety of gas sensing applications. However, the stability of the sensors' polymer coatings over a longer period of use has hardly been investigated. We used an array of eight STW resonator sensors coated with different polymers. This sensor array was used at semi-annual intervals for a three-year period to detect organic solvent vapors of three different chemical classes: a halogenated hydrocarbon (chloroform), an aliphatic hydrocarbon (octane), and an aromatic hydrocarbon (xylene). The sensor signals were evaluated with regard to absolute signal shifts and normalized signal shifts leading to signal patterns characteristic of the respective solvent vapors. No significant time-related changes of sensor signals or signal patterns were observed, i.e., the polymer coatings kept their performance during the course of the study. Therefore, the polymer-coated STW sensors proved to be robust devices which can be used for detecting organic solvent vapors both qualitatively and quantitatively for several years.

  5. Application of method of organizational congruences to substitution of organic solvents with vegetable agents for cleaning offset printing machine

    Energy Technology Data Exchange (ETDEWEB)

    Salerno, S [ENEA, Casaccia (Italy). Area Energia Ambiente e Salute; Tartaglia, R [Unita Sanitaria Locale 10/D, Firenze (Italy); Garzi, S; Biagioni, A [Istituto tecnico Leonardo da Vinci, Firenze (Italy)

    1995-06-01

    The aim of this research is the application of the method of organizational congruences before and after the substitution of organic solvents with vegetable agents for the cleaning offset printing machine in order to assess the organizational changes. A solvent free process is the goal of the SUBSPRINT project (Technology Transfer Program of the European Community). In this study it is shown how human and environmental health is improved by using vegetable agents through this change may lead to some other organizational constraints such as the time needed, the monotony and repetitiveness of the technical actions involved. The authors underline that the knowledge of the new technology impact of health help for a better understanding of the resistance to the change and help for a further amelioration of it.

  6. Removal of pollutants from surface water and groundwater by nanofiltration: overview of possible applications in the drinking water industry

    International Nuclear Information System (INIS)

    Bruggen, Bart van der; Vandecasteele, Carlo

    2003-01-01

    The nanofiltration system has many potential uses in removing chemical and biological contaminants from water. - During the last decade, nanofiltration (NF) made a breakthrough in drinking water production for the removal of pollutants. The combination of new standards for drinking water quality and the steady improvement of the nanofiltration process have led to new insights, possible applications and new projects on lab-scale, pilot scale and industrial scale. This paper offers an overview of the applications in the drinking water industry that have already been realised or that are suggested on the basis of lab-scale research. Applications can be found in the treatment of surface water as well as groundwater. The possibility of using NF for the removal of hardness, natural organic material (NOM), micropollutants such as pesticides and VOCs, viruses and bacteria, salinity, nitrates, and arsenic will be discussed. Some of these applications have proven to be reliable and can be considered as known techniques; other applications are still studied on laboratory scale. Modelling is difficult due to effects of fouling and interaction between different components. The current insight in the separation mechanisms will be briefly discussed

  7. Organic solvent and temperature-enhanced ion chromatography-high resolution mass spectrometry for the determination of low molecular weight organic and inorganic anions

    International Nuclear Information System (INIS)

    Gilchrist, Elizabeth S.; Nesterenko, Pavel N.; Smith, Norman W.; Barron, Leon P.

    2015-01-01

    Highlights: • IC selectivity at high contents of organic solvent in eluent and elevated temperature is studied. • Solvent-enhanced IC coupled to high resolution MS is beneficial for sensitive detection of ions. • The first application of IC-HRMS to the detection of low explosives in fingermarks is shown. - Abstract: There has recently been increased interest in coupling ion chromatography (IC) to high resolution mass spectrometry (HRMS) to enable highly sensitive and selective analysis. Herein, the first comprehensive study focusing on the direct coupling of suppressed IC to HRMS without the need for post-suppressor organic solvent modification is presented. Chromatographic selectivity and added HRMS sensitivity offered by organic solvent-modified IC eluents on a modern hyper-crosslinked polymeric anion-exchange resin (IonPac AS18) are shown using isocratic eluents containing 5–50 mM hydroxide with 0–80% methanol or acetonitrile for a range of low molecular weight anions (<165 Da). Comprehensive experiments on IC thermodynamics over a temperature range between 20–45 °C with the eluent containing up to 60% of acetonitrile or methanol revealed markedly different retention behaviour and selectivity for the selected analytes on the same polymer based ion-exchange resin. Optimised sensitivity with HRMS was achieved with as low as 30–40% organic eluent content. Analytical performance characteristics are presented and compared with other IC-MS based works. This study also presents the first application of IC-HRMS to forensic detection of trace low-order anionic explosive residues in latent human fingermarks

  8. Organic solvent and temperature-enhanced ion chromatography-high resolution mass spectrometry for the determination of low molecular weight organic and inorganic anions

    Energy Technology Data Exchange (ETDEWEB)

    Gilchrist, Elizabeth S. [Analytical & Environmental Science Division, Department of Forensic & Analytical Science, King’s College London, 150 Stamford Street, London, SE1 9NH (United Kingdom); Nesterenko, Pavel N. [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart 7001 (Australia); Smith, Norman W. [Analytical & Environmental Science Division, Department of Forensic & Analytical Science, King’s College London, 150 Stamford Street, London, SE1 9NH (United Kingdom); Barron, Leon P., E-mail: leon.barron@kcl.ac.uk [Analytical & Environmental Science Division, Department of Forensic & Analytical Science, King’s College London, 150 Stamford Street, London, SE1 9NH (United Kingdom)

    2015-03-20

    Highlights: • IC selectivity at high contents of organic solvent in eluent and elevated temperature is studied. • Solvent-enhanced IC coupled to high resolution MS is beneficial for sensitive detection of ions. • The first application of IC-HRMS to the detection of low explosives in fingermarks is shown. - Abstract: There has recently been increased interest in coupling ion chromatography (IC) to high resolution mass spectrometry (HRMS) to enable highly sensitive and selective analysis. Herein, the first comprehensive study focusing on the direct coupling of suppressed IC to HRMS without the need for post-suppressor organic solvent modification is presented. Chromatographic selectivity and added HRMS sensitivity offered by organic solvent-modified IC eluents on a modern hyper-crosslinked polymeric anion-exchange resin (IonPac AS18) are shown using isocratic eluents containing 5–50 mM hydroxide with 0–80% methanol or acetonitrile for a range of low molecular weight anions (<165 Da). Comprehensive experiments on IC thermodynamics over a temperature range between 20–45 °C with the eluent containing up to 60% of acetonitrile or methanol revealed markedly different retention behaviour and selectivity for the selected analytes on the same polymer based ion-exchange resin. Optimised sensitivity with HRMS was achieved with as low as 30–40% organic eluent content. Analytical performance characteristics are presented and compared with other IC-MS based works. This study also presents the first application of IC-HRMS to forensic detection of trace low-order anionic explosive residues in latent human fingermarks.

  9. Retention measurements of nanofiltration membranes with electrolyte solutions

    NARCIS (Netherlands)

    Peeters, J.M.M.; Peeters, J.M.M.; Boom, J.P.; Boom, J.P.; Mulder, M.H.V.; Strathmann, H.

    1998-01-01

    Retention measurements with single salt solutions of CaCl2, NaCl and Na2SO4 revealed that the rejection mechanism of commercial polymeric nanofiltration membranes investigated in this study may be divided into two categories: 1. Membranes for which Donnan exclusion seems to play an important role.

  10. EVALUATION OF NANOFILTRATION PRETREATMENTS FOR FLUX LOSS CONTROL

    Science.gov (United States)

    Differing nanofiltration pretreatment approaches for Ohio River water were evaluated withthe intent of producing systems with varying degrees of biological fouling. The membrane feed water was alum-coagulated, settled, and filtered Ohio River water (SF-ORW). Five 1.8" x 12" N...

  11. The applicability of nanofiltration for the treatment and reuse of ...

    African Journals Online (AJOL)

    The main aim of the study was to test the feasibility of using nanofiltration (NF) processes for the treatment of reactive dyebath effluents from the textile industry, in order to recover the water and chemicals (salts) for reuse purposes. The study of the reusability of nanofiltered water for dyeing has been given little or no ...

  12. Predicting the Disorder–Order Transition of Solvent-Free Nanoparticle–Organic Hybrid Materials

    KAUST Repository

    Yu, Hsiu-Yu

    2013-07-02

    The transition from a disordered to a face-centered-cubic phase in solvent-free oligomer-tethered nanoparticles is predicted using a density-functional theory for model hard spheres with tethered bead-spring oligomers. The transition occurs without a difference of volume fraction for the two phases, and the phase boundary is influenced by the loss of oligomer configurational entropy relative to an ideal random system in one phase compared with the other. When the particles are localized in the ordered phase, the cooperation of the oligomers in filling the space is hindered. Therefore, shorter oligomers feel a stronger entropic penalty in the ordered solid and favor the disordered phase. Strikingly, we found that the solvent-free system has a later transition than hard spheres for all investigated ratios of oligomer radius of gyration to particle radius. © 2013 American Chemical Society.

  13. Systematic investigations on acyclic organic carbonate solvents for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, J.; Peter, S.; Novak, P.

    2003-03-01

    Electrochemical cycling tests on cells with graphite electrodes and several alkyl methyl carbonates were performed. Experiments with mixed binary solvent electrolytes with ethylene carbonate (EC) showed that the alkyl methyl carbonates H{sub 3}CO(CO)O(CH{sub 2}){sub n}H (n = 3-5) are suitable as co-solvents in lithium-ion batteries. Ternary mixtures of EC, BMC, and propylene carbonate (PC) showed better overall performances than EC/PC electrolytes. The branched isobutyl methyl carbonate (i-BMC) outperforms its linear isomer (BMC) in terms of electrochemical performance. LiPF{sub 6} is superior to LiClO{sub 4} as conducting salt in both EC/BMC and EC/i-BMC mixtures in terms of electrolyte conductivity, rate capability, and cycling stability. (author)

  14. Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

    Directory of Open Access Journals (Sweden)

    Martin Obst

    2016-11-01

    Full Text Available A method for the solvent-free photocatalytic conversion of solid and liquid substrates was developed, using a novel rod mill apparatus. In this setup, thin liquid films are realized which is crucial for an effective photocatalytic conversion due to the low penetration depth of light in heterogeneous systems. Several benzylic alcohols were oxidized with riboflavin tetraacetate as photocatalyst under blue light irradiation of the reaction mixture. The corresponding carbonyl compounds were obtained in moderate to good yields.

  15. Accelerating Palladium Nanowire H2 Sensors Using Engineered Nanofiltration.

    Science.gov (United States)

    Koo, Won-Tae; Qiao, Shaopeng; Ogata, Alana F; Jha, Gaurav; Jang, Ji-Soo; Chen, Vivian T; Kim, Il-Doo; Penner, Reginald M

    2017-09-26

    The oxygen, O 2 , in air interferes with the detection of H 2 by palladium (Pd)-based H 2 sensors, including Pd nanowires (NWs), depressing the sensitivity and retarding the response/recovery speed in air-relative to N 2 or Ar. Here, we describe the preparation of H 2 sensors in which a nanofiltration layer consisting of a Zn metal-organic framework (MOF) is assembled onto Pd NWs. Polyhedron particles of Zn-based zeolite imidazole framework (ZIF-8) were synthesized on lithographically patterned Pd NWs, leading to the creation of ZIF-8/Pd NW bilayered H 2 sensors. The ZIF-8 filter has many micropores (0.34 nm for gas diffusion) which allows for the predominant penetration of hydrogen molecules with a kinetic diameter of 0.289 nm, whereas relatively larger gas molecules including oxygen (0.345 nm) and nitrogen (0.364 nm) in air are effectively screened, resulting in superior hydrogen sensing properties. Very importantly, the Pd NWs filtered by ZIF-8 membrane (Pd NWs@ZIF-8) reduced the H 2 response amplitude slightly (ΔR/R 0 = 3.5% to 1% of H 2 versus 5.9% for Pd NWs) and showed 20-fold faster recovery (7 s to 1% of H 2 ) and response (10 s to 1% of H 2 ) speed compared to that of pristine Pd NWs (164 s for response and 229 s for recovery to 1% of H 2 ). These outstanding results, which are mainly attributed to the molecular sieving and acceleration effect of ZIF-8 covered on Pd NWs, rank highest in H 2 sensing speed among room-temperature Pd-based H 2 sensors.

  16. Determination of Terpenoid Content in Pine by Organic Solvent Extraction and Fast-GC Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Harman-Ware, Anne E., E-mail: anne.ware@nrel.gov; Sykes, Robert [National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO (United States); Peter, Gary F. [School of Forest Resources and Conservation, University of Florida, Gainesville, FL (United States); Davis, Mark [National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO (United States)

    2016-01-25

    Terpenoids, naturally occurring compounds derived from isoprene units present in pine oleoresin, are a valuable source of chemicals used in solvents, fragrances, flavors, and have shown potential use as a biofuel. This paper describes a method to extract and analyze the terpenoids present in loblolly pine saplings and pine lighter wood. Various extraction solvents were tested over different times and temperatures. Samples were analyzed by pyrolysis-molecular beam mass spectrometry before and after extractions to monitor the extraction efficiency. The pyrolysis studies indicated that the optimal extraction method used a 1:1 hexane/acetone solvent system at 22°C for 1 h. Extracts from the hexane/acetone experiments were analyzed using a low thermal mass modular accelerated column heater for fast-GC/FID analysis. The most abundant terpenoids from the pine samples were quantified, using standard curves, and included the monoterpenes, α- and β-pinene, camphene, and δ-carene. Sesquiterpenes analyzed included caryophyllene, humulene, and α-bisabolene. Diterpenoid resin acids were quantified in derivatized extractions, including pimaric, isopimaric, levopimaric, palustric, dehydroabietic, abietic, and neoabietic acids.

  17. An odd–even effect on solubility of dicarboxylic acids in organic solvents

    International Nuclear Information System (INIS)

    Zhang, Hui; Yin, Qiuxiang; Liu, Zengkun; Gong, Junbo; Bao, Ying; Zhang, Meijing; Hao, Hongxun; Hou, Baohong; Xie, Chuang

    2014-01-01

    Highlights: • The solubilities of the homologous series of C2–C10 dicarboxylic acids were determined in four selected solvents. • The experimental data were well correlated with the modified Apelblat equation. • The odd–even effect of solubility was found and explained. • The enthalpy, entropy and the molar Gibbs free energy of solution were predicted. - Abstract: The solubility of the homologous series of dicarboxylic acids, HOOC-(CH 2 ) n−2 -COOH (n = 2 to 10), in ethanol, acetic acid, acetone and ethyl acetate was measured at temperatures ranging from (278.15 to 323.15) K by a static analytic method at atmospheric pressure. Dicarboxylic acids with even number of carbon atoms exhibit lower values of solubility than adjacent homologues with odd carbon numbers. This odd–even effect of solubility is attributed to the twist of molecules and interlayer packing in solid state as explained in our previous work. The alternation varies in different solvents, which is believed to be associated with the properties of solvents. Finally, the dissolution enthalpy, dissolution entropy and the molar Gibbs free energy were calculated using the fitting parameters of the modified Apelblat equation. The molar Gibbs free energy also showed apparent odd–even alternation in keeping with the alternation of solubility

  18. Enthalpy of solution of α- and β-cyclodextrin in water and in some organic solvents

    International Nuclear Information System (INIS)

    Belica, Sylwia; Sadowska, Monika; Stępniak, Artur; Graca, Anna; Pałecz, Bartłomiej

    2014-01-01

    Highlights: • A great influence of crystalline water on the energetic of dissolving compounds. • The strongest interaction between β-cyclodextrin and DMSO. • The enthalpic pair interaction coefficient, h βCD-EtOH , obtained is positive. • Predominating effects of the partial dehydration of the molecules – βCD-EtOH. -- Abstract: The calorimetric measurements of solution enthalpy of α-cyclodextrin, β-cyclodextrin in water (H 2 O), dimetyloformamid (DMF), dimethyl sulfoxide (DMSO) and aqueous ethanol solutions (H 2 O + EtOH) at 298.15 K were made. The experimental results were used to calculate the enthalpic coefficients of the interactions between cyclodextrin and ethanol molecules in water based on McMillan–Mayer’s model. The results were compared with literature data and with hydrodynamic radii of cyclodextrin in examined solvents and with donor numbers of these solvents. In order to check, if the inclusion complex formation between the solvent with the highest enthalpy of solution and cyclodextrin has happened, the calorimetric isothermal titration measurements were made and the results were interpreted

  19. Determination of Terpenoid Content in Pine by Organic Solvent Extraction and Fast-GC Analysis

    International Nuclear Information System (INIS)

    Harman-Ware, Anne E.; Sykes, Robert; Peter, Gary F.; Davis, Mark

    2016-01-01

    Terpenoids, naturally occurring compounds derived from isoprene units present in pine oleoresin, are a valuable source of chemicals used in solvents, fragrances, flavors, and have shown potential use as a biofuel. This paper describes a method to extract and analyze the terpenoids present in loblolly pine saplings and pine lighter wood. Various extraction solvents were tested over different times and temperatures. Samples were analyzed by pyrolysis-molecular beam mass spectrometry before and after extractions to monitor the extraction efficiency. The pyrolysis studies indicated that the optimal extraction method used a 1:1 hexane/acetone solvent system at 22°C for 1 h. Extracts from the hexane/acetone experiments were analyzed using a low thermal mass modular accelerated column heater for fast-GC/FID analysis. The most abundant terpenoids from the pine samples were quantified, using standard curves, and included the monoterpenes, α- and β-pinene, camphene, and δ-carene. Sesquiterpenes analyzed included caryophyllene, humulene, and α-bisabolene. Diterpenoid resin acids were quantified in derivatized extractions, including pimaric, isopimaric, levopimaric, palustric, dehydroabietic, abietic, and neoabietic acids.

  20. Characterization of inclusion complexes of organic ions with hydrophilic hosts by ion transfer voltammetry with solvent polymeric membranes.

    Science.gov (United States)

    Olmos, José Manuel; Laborda, Eduardo; Ortuño, Joaquín Ángel; Molina, Ángela

    2017-03-01

    The quantitative characterization of inclusion complexes formed in aqueous phase between organic ions and hydrophilic hosts by ion-transfer voltammetry with solvent polymeric membrane ion sensors is studied, both in a theoretical and experimental way. Simple analytical solutions are presented for the determination of the binding constant of the complex from the variation with the host concentration of the electrochemical signal. These solutions are valid for any voltammetric technique and for solvent polymeric membrane ion sensors comprising one polarisable interface (1PI) and also, for the first time, two polarisable interfaces (2PIs). Suitable experimental conditions and data analysis procedures are discussed and applied to the study of the interactions of a common ionic liquid cation (1-octyl-3-metyl-imidazolium) and an ionisable drug (clomipramine) with two hydrophilic cyclodextrins: α-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin. The experimental study is performed via square wave voltammetry with 2PIs and 1PI solvent polymeric membranes and in both cases the electrochemical experiments enable the detection of inclusion complexes and the determination of the corresponding binding constant. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Enzymatic synthesis of 6-O-glucosyl-poly(3-hydroxyalkanoate) in organic solvents and their binary mixture.

    Science.gov (United States)

    Gumel, A M; Annuar, M S M; Heidelberg, T

    2013-04-01

    The effects of organic solvents and their binary mixture in the glucose functionalization of bacterial poly-3-hydroxyalkanoates catalyzed by Lecitase™ Ultra were studied. Equal volume binary mixture of DMSO and chloroform with moderate polarity was more effective for the enzyme catalyzed synthesis of the carbohydrate polymer at ≈38.2 (±0.8)% reactant conversion as compared to the mono-phasic and other binary solvents studied. The apparent reaction rate constant as a function of medium water activity (aw) was observed to increase with increasing solvent polarity, with optimum aw of 0.2, 0.4 and 0.7 (±0.1) observed in hydrophilic DMSO, binary mixture DMSO:isooctane and hydrophobic isooctane, respectively. Molecular sieve loading between 13 to 15gL(-1) (±0.2) and reaction temperature between 40 to 50°C were found optimal. Functionalized PHA polymer showed potential characteristics and biodegradability. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Impact of Organic Solvents and Environmental Pollutants on the Physiological Function in Petrol Filling Workers

    Directory of Open Access Journals (Sweden)

    V. Devender Reddy

    2008-09-01

    Full Text Available Long term exposure to solvents and air pollutants can lead to deleterious effects on respiratory, haematological and thyroid functioning. The aim of this study was to investigate whether chronic exposure to solvents like benzene and pollutants like carbon monoxide in petrol filling workers had adverse effect on blood parameters, thyroid and respiratory functions. The study group consisted of 42 healthy, non-smoker petrol filling workers, aged 20-50 years with work (exposure duration from 2-15 years while 36 healthy subjects of the same age group served as controls. Physical examination and measurement of pulmonary functions by portable electronic spirometer were performed. Complete blood pictures (CBP were determined by normal haematology lab procedure and hormones by Chemiluminescence immunoassay (CLIA light absorption techniques. There was a significant decrease in the lung volumes and capacities; the restrictive pattern was more prevalent in the workers when compared with the control groups. But in the workers exposed for long period (more than 10 years the restrictive pattern was changed to mixed pattern. A significant increase in haemoglobin (Hb (>16 mg % and red blood cells (RBC (5.4 million cells/mm3 were observed in workers with longer period of exposure when compared with the control subjects (14.483 mg% and 4.83 million cells/mm3 for Hb and RBC respectively. White blood cell count except eosinophils and platelets were significantly lower in workers compared to controls. Marked increase in the tetra iodothyroinine (T4, free thyroxine (T4F level and significant decrease in thyroid stimulating hormones (TSH, and tri-iodothyronine (T3 were observed between long term exposed and non – exposed groups. Till now researchers focused only on the effect of solvents in workers professionally exposed to solvents without considering the effect of concomittant air pollution. The result obtained from present study indicates that there is

  3. Impact of organic solvents and environmental pollutants on the physiological function in petrol filling workers.

    Science.gov (United States)

    Uzma, Nazia; Salar, B M Khaja Mohinuddin; Kumar, B Santhosh; Aziz, Nusrat; David, M Anthony; Reddy, V Devender

    2008-09-01

    Long term exposure to solvents and air pollutants can lead to deleterious effects on respiratory, haematological and thyroid functioning. The aim of this study was to investigate whether chronic exposure to solvents like benzene and pollutants like carbon monoxide in petrol filling workers had adverse effect on blood parameters, thyroid and respiratory functions. The study group consisted of 42 healthy, non-smoker petrol filling workers, aged 20-50 years with work (exposure) duration from 2-15 years while 36 healthy subjects of the same age group served as controls. Physical examination and measurement of pulmonary functions by portable electronic spirometer were performed. Complete blood pictures (CBP) were determined by normal haematology lab procedure and hormones by Chemiluminescence immunoassay (CLIA) light absorption techniques. There was a significant decrease in the lung volumes and capacities; the restrictive pattern was more prevalent in the workers when compared with the control groups. But in the workers exposed for long period (more than 10 years) the restrictive pattern was changed to mixed pattern. A significant increase in haemoglobin (Hb) (>16 mg %) and red blood cells (RBC) (5.4 million cells/mm3) were observed in workers with longer period of exposure when compared with the control subjects (14.483 mg% and 4.83 million cells/mm3 for Hb and RBC respectively). White blood cell count except eosinophils and platelets were significantly lower in workers compared to controls. Marked increase in the tetra iodothyroinine (T4), free thyroxine (T4F) level and significant decrease in thyroid stimulating hormones (TSH), and tri-iodothyronine (T3) were observed between long term exposed and non-exposed groups. Till now researchers focused only on the effect of solvents in workers professionally exposed to solvents without considering the effect of concomittant air pollution. The result obtained from present study indicates that there is a significant toxic

  4. Temperature effects on separation of Gd3+ from Gd-DTPA-folate using nanofiltration method

    Science.gov (United States)

    Rahayu, I.; Indraneli, R. P.; Yuliyati, Y. B.; Anggraeni, A.; Soedjanaatmadja, U. M. S.; Bahti, H. H.

    2018-05-01

    MRI is one of the best techniques in medical diagnostics. Contrast agents are used to improve the visual of organs that are difficult to distinguish through MRI. Gd-DTPA-folate is one of the specific contrast agents against cancer diagnosis, because it has a high affinity to folate receptors. In the complexing Gd-DTPA-folate, does not rule out the complexity step runs imperfectly, so there is still Gd3+ in the Gd-DTPA-folate complex. The separation of Gd3+ from the Gd-DTPA-folate complex is important to eliminate toxic effects on the contrast agent. This study aims to determine the effect of temperature on the separation of Gd-DTPA-folate from Gd3+ with nanofiltration. The method are preparation Gd-DTPA-folate from GdCl3.6H2O and DTPA-folate by reflux method, then separated Gd-DTPA-folate complex from Gd3+ with nanofiltration at variation temperature (40, 41, 42, 43, 44oC ). Then, the values of flux and rejection coefficients were analyzed. The results showed that the optimum temperature for the separation of Gd3+ from Gd-DTPA-folate was achieved at 42.6°C with the rejection coefficient of 24% and the permeate flux of 403 L.m-2.h-1.

  5. Study of acid-base properties in various water-salt and water-organic solvent mixtures

    International Nuclear Information System (INIS)

    Lucas, M.

    1969-01-01

    Acid-base reactions have been studied in water-salt mixtures and water organic solvent-mixtures. It has been possible to find some relations between the displacement of the equilibria and the numerical value of water activity in the mixture. First have been studied some equilibria H + + B ↔ HB + in salt-water mixtures and found a relation between the pK A value, the solubility of the base and water activity. The reaction HO - + H + ↔ H 2 O has been investigated and a relation been found between pK i values, water activity and the molar concentration of the salt in the mixture. This relation is the same for every mixture. Then the same reactions have been studied in organic solvent-water mixtures and a relation found in the first part of the work have been used with success. So it has been possible to explain easily some properties of organic water-mixture as the shape of the curves of the Hammett acidity function Ho. (authors) [fr

  6. System Development from Organic Solvents to Ionic Liquids for Synthesiz-ing Ascorbyl Esters with Conjugated Linoleic Acids

    DEFF Research Database (Denmark)

    Yang, Zhiyong; Schultz, Lise; Guo, Zheng

    2012-01-01

    . Results show that only Novozym® 435 turned out to be a useful enzymatic preparation for the production of ascorbyl-CLA ester. The optimum reaction conditions in the or-ganic solvent system were 4 h at 55°C and at a molar ratio of 5 (CLA/ascorbic acid). The esterification reaction was trans......-ferred to an ionic liquid system for the purpose of improving solubility of the polar substrate and avoiding the application of organic solvents. From screening experiments, it was evident that only methyltrioctylammonium triflouroacetate (tO-MA·TFA) could provide a proper reaction environment for production...... of ascorbyl-CLA ester when using Novozym® 435 as biocatalyst. It was possible to significantly increase the productivity (150 g/l) through the increase of ascorbic acid sol-ubility in ionic liquids by super saturation together with the increase of reaction temperature to 70°C, far beyond than that in organic...

  7. [Neurologic diagnosis and certification in persons chronically exposed to certain organic solvents in light of personal cases].

    Science.gov (United States)

    Sińczuk-Walczak, H

    1995-01-01

    A clinical picture of selected cases diagnosed or suspected of chronic poisoning by organic solvents such as: Trichlorethylene (TRI), Tetrachlorethylene (PER), Carbon Disulfide (CS2) is presented. Based on examples of diagnosed neurological syndromes, some diagnostic and certification issues concerning occupational diseases of the neurological system, are analysed. An objective assessment of patients' complaints, differentiation between occupational diseases, so called idiopathic diseases of the nervous system, selection of appropropriate diagnostic methods in order to confirm or exclude these diseases belong to essential problems among those discussed.

  8. Solvent-Assisted Gel Printing for Micropatterning Thin Organic-Inorganic Hybrid Perovskite Films.

    Science.gov (United States)

    Jeong, Beomjin; Hwang, Ihn; Cho, Sung Hwan; Kim, Eui Hyuk; Cha, Soonyoung; Lee, Jinseong; Kang, Han Sol; Cho, Suk Man; Choi, Hyunyong; Park, Cheolmin

    2016-09-27

    While tremendous efforts have been made for developing thin perovskite films suitable for a variety of potential photoelectric applications such as solar cells, field-effect transistors, and photodetectors, only a few works focus on the micropatterning of a perovskite film which is one of the most critical issues for large area and uniform microarrays of perovskite-based devices. Here we demonstrate a simple but robust method of micropatterning a thin perovskite film with controlled crystalline structure which guarantees to preserve its intrinsic photoelectric properties. A variety of micropatterns of a perovskite film are fabricated by either microimprinting or transfer-printing a thin spin-coated precursor film in soft-gel state with a topographically prepatterned elastomeric poly(dimethylsiloxane) (PDMS) mold, followed by thermal treatment for complete conversion of the precursor film to a perovskite one. The key materials development of our solvent-assisted gel printing is to prepare a thin precursor film with a high-boiling temperature solvent, dimethyl sulfoxide. The residual solvent in the precursor gel film makes the film moldable upon microprinting with a patterned PDMS mold, leading to various perovskite micropatterns in resolution of a few micrometers over a large area. Our nondestructive micropatterning process does not harm the intrinsic photoelectric properties of a perovskite film, which allows for realizing arrays of parallel-type photodetectors containing micropatterns of a perovskite film with reliable photoconduction performance. The facile transfer of a micropatterned soft-gel precursor film on other substrates including mechanically flexible plastics can further broaden its applications to flexible photoelectric systems.

  9. Ultrasonic and viscometric studies of yttrium soaps in mixed organic solvents

    International Nuclear Information System (INIS)

    Mehrotra, K.N.; Tandon, K.; Rawat, M.K.

    1992-01-01

    The ultrasonic and viscosity measurements of yttrium soaps (caprylate, caprate and laurate) in a mixture of benzene and dimethyl formamide (3:2) have been carried out with a view to determine the critical micellar concentration soap-solvent interaction and other allied parameters. The various acoustic parameters (intermolecular free-length adiabatic compressibility, apparent molar compressibility, specific acoustic impedance, molar sound velocity, solvation number available volume and relative association) have been evaluated by ultrasonic velocity measurements. The results of viscosity measurement have been explained in terms of well known equations. (author). 18 refs., 2 figs., 3 tabs

  10. The distribution of n-caprylic acid between organic solvents and aqueous sodium sulfate solution

    International Nuclear Information System (INIS)

    Gloe, K.; Muehl, P.; Kholkin, A.I.; Gindin, L.M.

    1981-01-01

    The distribution of 14 C-labelled n-caprylic acid between n-decane, benzene, isoamyl acetate, diisopropyl ketone, isoamyl alcohol and an aqueous 0.6 molar sodium sulfate solution was studied. The distribution constants and the dimerisation constants were determined for the reactions HRsub((w)) reversible HRsub((org)) and 2 HRsub((org)) reversible (HR)sub(2(org)), respectively. Both the effect of the solvent on the acid distribution and the importance of such studies for the interpretation of liquid-liquid extraction equilibria are discussed. (author)

  11. Ultrasonic measurements and other allied parameters of yttrium soaps in mixed organic solvents

    International Nuclear Information System (INIS)

    Mehrotra, K.N.; Tandon, K.

    1990-01-01

    The ultrasonic measurements of yttrium soaps were made in a mixture of 70 % benzene and 30 % dimethylsulfoxide (ν/ν) to determine the critical micelle concentration, soap-solvent interaction and various acoustic and thermodynamic parameters. The values of the CMC decrease with increasing chainlength of fatty acid constituent of the soap molecule and are in agreement with the values obtained from other micellar properties. The various acoustic parameters (intermolecular freelength, adiabatic compressibility, apparent molar compressibility, specific acoustic impedance, apparent molar volume, molar sound velocity, solvation number, available volume and relative association) for yttrium soaps (myristate, palmitate, stearate and oleate) have been evaluated by ultrasonic velocity measurements. (Authors)

  12. Determination of organic bases in non-aqueous solvents by catalytic thermometric titration.

    Science.gov (United States)

    Vajgand, V J; Kiss, T A; Gaál, F F; Zsigrai, I J

    1968-07-01

    Catalytic thermometric titrations have been developed for bases (brucine, diethylaniline, potassium acetate and triethylamine) in acetic acid by continuous and discontinuous addition of the standard solution and automatic temperature recording. The determination of weak bases, e.g., antipyrine, unsuccessful in acetic acid by catalytic thermometric titration, has been achieved by using nitromethane or acetic anhydride as solvent. Catalytic thermometric titrations were also performed by coulometric generation of hydrogen ions for the determination of micro amounts of weak bases in a mixture of acetic anhyride and acetic acid.

  13. Esterase Active in Polar Organic Solvents from the Yeast Pseudozyma sp. NII 08165

    Directory of Open Access Journals (Sweden)

    Deepthy Alex

    2014-01-01

    Full Text Available Esterases/lipases active in water miscible solvents are highly desired in biocatalysis where substrate solubility is limited and also when the solvent is desired as an acyl acceptor in transesterification reactions, as with the case of biodiesel production. We have isolated an esterase from the glycolipid producing yeast-Pseudozyma sp. NII 08165 which in its crude form was alkali active, thermo stable, halo tolerant and also capable of acting in presence of high methanol concentration. The crude enzyme which maintained 90% of its original activity after being treated at 70°C was purified and the properties were characterized. The partially purified esterase preparation had temperature and pH optima of 60°C and 8.0 respectively. The enzyme retained almost complete activity in presence of 25% methanol and 80% activity in the same strength of ethanol. Conditions of enzyme production were optimized, which lead to 9 fold increase in the esterase yield. One of the isoforms of the enzyme LIP1 was purified to homogeneity and characterized. Purified LIP1 had a Km and Vmax of 0.01 and 1.12, respectively. The purified esterase lost its thermo and halo tolerance but interestingly, retained 97% activity in methanol.

  14. Characterization and Storage Stability Study of Bixin Extracted from Bixa orellana Using Organic Solvent

    Science.gov (United States)

    Husa, N. N.; Hamzah, F.; Said, H. M.

    2018-05-01

    Colorant is one of the additives to give a better appearance or improve the colour of the product. Synthetic colorant has been widely used in industrial due to its readiness in the market and its colour stability. However the arising issues related to the safety, nutrition and also the therapeutic effect has encouraged users to become more concern about the colouring component. Thus, the present research was conducted in order to produce natural colorant called bixin from Bixa orellana or also known as annatto seeds. The study was focusing on the effect of the solvent on the characteristic and concentration of the extracted bixin. While stability of the bixin during different storage condition was determined to further validate the effectiveness of the solvent. The result indicated that methanol and acetone gave darker of the bixin colour as compared to the water. However, the deterioration rate of the bixin in acetone and methanol were faster as compared to the water. The extracted bixin was analysed using Fourier-transform infrared spectroscopy (FTIR) and spectrophotometer analysis. The strong band for the bixin was observed at absorbance range of 1704 – 1740cm-1. The study indicates that the concentration of the extracted bixin was the highest in methanol which gave 817.7 ppm of bixin. Meanwhile, bixin concentration in acetone and water was 602.9 ppm and 477.19 ppm respectively.

  15. Extraction of garlic with supercritical CO2 and conventional organic solvents

    Directory of Open Access Journals (Sweden)

    J. M. del Valle

    2008-09-01

    Full Text Available Garlic (Allium sativum L. and garlic extracts have therapeutical properties that stem from their sulfur-containing compounds, mainly allicin. The main objective of this work was to compare conventional and "premium" garlic extracts in terms of yield and quality, with the latter being obtained using supercritical carbon dioxide (SC-CO2 as the solvent. Yield ranged between 0.65 and 1.0% and increased with extraction pressure (150-400 bar at a constant temperature of 50°C. Extraction temperature (35-60°C, on the other hand, had little effect at a constant pressure of 300 bar. Based on yield and quality considerations, the best extraction conditions using SC-CO2 were 35-50°C and 300-400 bar. A yield of 5.5% was obtained by conventional extraction using ethanol as the solvent, but ethanol appeared to be less selective for valuable components than SC-CO2. The use of fresh garlic resulted in extracts that more closely resembled commercial products, possibly because of thermal and oxidative degradation of valuable microconstituents during drying.

  16. Exposure to organic solvents in the offset printing industry in Norway.

    Science.gov (United States)

    Svendsen, K; Rognes, K S

    2000-03-01

    The purpose of this study was to document the conditions regarding solvent exposure at offset printing offices in Norway at present and to study the variation of exposure between printing office technologies. Measurements were made at seven offset printing offices. The measurements consisted of five to 10 whole day personal exposure measurements at each office performed over a period of 2 months. Variables that may influence the level of exposure were registered by the occupational hygienist at the end of each measuring day using a check list. The influence of the variables on the "additive factor" was examined by linear regression analysis.The main contributor to the "additive factor" was isopropanol. The exposure to isopropanol sometimes exceeded the Norwegian TLV. The exposure decreased when a separate exhaust ventilation was used. The exposure increased when the machine had automatic cleaning. The variables automatic cleaning and separate exhaust ventilation explained 59% of the variation in the "additive factor". The results of this study indicate that the most important source of solvent exposure in printing offices at present is the moisturizer used in the printing machines. We think it is worth giving attention to this exposure and making efforts to reduce it.

  17. Application of acid-catalyzed hydrolysis of dispersed organic solvent in developing new microencapsulation process technology.

    Science.gov (United States)

    Lee, Honghwa; Lee, Sunhwa; Bhattacharjee, Himanshu; Sah, Hongkee

    2012-01-01

    The aim of this study was to evaluate a new microencapsulation technology employing an acid-catalyzed solvent extraction method in conjunction to an emulsion-based microencapsulation process. Its process consisted of emulsifying a dispersed phase of poly(D,L-lactide-co-glycolide) and isopropyl formate in an aqueous phase. This step was followed by adding hydrochloric acid to the resulting oil-in-water emulsion, in order to initiate the hydrolysis of isopropyl formate dissolved in the aqueous phase. Its hydrolysis caused the liberation of water-soluble species, that is, isopropanol and formic acid. This event triggered continual solvent leaching out of emulsion droplets, thereby initiating microsphere solidification. This new processing worked well for encapsulation of progesterone and ketoprofen that were chosen as a nonionizable model drug and a weakly acidic one, respectively. Furthermore, the structural integrity of poly(D,L-lactide-co-glycolide) was retained during microencapsulation. The new microencapsulation technology, being conceptually different from previous approaches, might be useful in preparing various polymeric particles.

  18. Polysulfone thin film composite nanofiltration membranes for removal of textile dyes wastewater

    Science.gov (United States)

    Sutedja, Andrew; Aileen Josephine, Claresta; Mangindaan, Dave

    2017-12-01

    This research was conducted to produce nanofiltration (NF) membranes, which have good performance in terms of removal of textile dye (Reactive Red 120, RR120) from simulated wastewater as one of several eco-engineering developments for sustainable water resource management. Phase inversion technique was utilized to fabricate the membrane with polysulfone (PSF) support, dissolved in N-methyl-2 pyrollidone (NMP) solvent, and diethylene glycol (DEG) as non-solvent additive. The fabricated membrane then modified with the additional of dopamine coating and further modified by interfacial polymerization (IP) to form a thin film composite (TFC)-NF membrane with PSF substrate. TFC was formed from interaction between amine monomer (2 %-weight of m-phenylenediamine (MPD) in deionized water) and acyl chloride (0.2 %-weight of trimesoyl chloride (TMC) in hexane). From this study, the fabricated PSF-TFC membrane could remove dyestuff from RR120 wastewater by 88% rejection at 120 psi. The result of this study is promising to be applied in Indonesia where researches on removal of dyes from textile wastewater by using membranes are still quite rare. Therefore, this paper may open new avenues for development of eco-engineering development in Indonesia.

  19. Production, Optimization, and Characterization of Organic Solvent Tolerant Cellulases from a Lignocellulosic Waste-Degrading Actinobacterium, Promicromonospora sp. VP111.

    Science.gov (United States)

    Thomas, Lebin; Ram, Hari; Kumar, Alok; Singh, Ved Pal

    2016-07-01

    High costs of natural cellulose utilization and cellulase production are an industrial challenge. In view of this, an isolated soil actinobacterium identified as Promicromonospora sp. VP111 showed potential for production of major cellulases (CMCase, FPase, and β-glucosidase) utilizing untreated agricultural lignocellulosic wastes. Extensive disintegration of microcrystalline cellulose and adherence on it during fermentation divulged true cellulolytic efficiency of the strain. Conventional optimization resulted in increased cellulase yield in a cost-effective medium, and the central composite design (CCD) analysis revealed cellulase production to be limited by cellulose and ammonium sulfate. Cellulase activities were enhanced by Co(+2) (1 mM) and retained up to 60 °C and pH 9.0, indicating thermo-alkaline tolerance. Cellulases showed stability in organic solvents (25 % v/v) with log P ow  ≥ 1.24. Untreated wheat straw during submerged fermentation was particularly degraded and yielded about twofold higher levels of cellulases than with commercial cellulose (Na-CMC and avicel) which is especially economical. Thus, this is the first detailed report on cellulases from an efficient strain of Promicromonospora that was non-hemolytic, alkali-halotolerant, antibiotic (erythromycin, kanamycin, rifampicin, cefaclor, ceftazidime) resistant, multiple heavy metal (Mo(+6) = W(+6) > Pb(+2) > Mn(+2) > Cr(+3) > Sn(+2)), and organic solvent (n-hexane, isooctane) tolerant, which is industrially and environmentally valuable.

  20. Rapid and simple purification of elastin-like polypeptides directly from whole cells and cell lysates by organic solvent extraction.

    Science.gov (United States)

    VerHeul, Ross; Sweet, Craig; Thompson, David H

    2018-03-26

    Elastin-like polypeptides (ELP) are a well-known class of proteins that are being increasingly utilized in a variety of biomedical applications, due to their beneficial physicochemical properties. A unifying feature of ELP is their demonstration of a sequence tunable inverse transition temperature (Tt) that enables purification using a simple, straightforward process called inverse transition cycling (ITC). Despite the utility of ITC, the process is inherently limited to ELP with an experimentally accessible Tt. Since the underlying basis for the ELP Tt is related to its high overall hydrophobicity, we anticipated that ELP would be excellent candidates for purification by organic extraction. We report the first method for rapidly purifying ELP directly from whole E. coli cells or clarified lysates using pure organic solvents and solvent mixtures, followed by aqueous back extraction. Our results show that small ELP and a large ELP-fusion protein can be isolated in high yield from whole cells or cell lysates with greater than 95% purity in less than 30 min and with very low levels of LPS and DNA contamination.

  1. Enzymatic synthesis of tasty oligopeptide in organic solvent. Yuki yobaichu deno teimisei origo pepuchido no koso gosei

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Tomita, K.; Nakanishi, K. (Okayama Univ., Okayama (Japan). Faculty of Engineering)

    1991-10-01

    An introduction is made to examples of the latest researches on methods to manufacture oligopeptides by enzymatic synthesizing methods in regards to to various processes using reactions in organic solvents as a means to increase the yield, particularly on synthesis of one that have taste effects. To raise the yield of peptides that are produced by condensing amino acid and amino acid derivatives, it is necessary that an equilibrium control reaction is operated in such a way that the product concentration and product moisture concentration are reduced, and the concentration of substrates of non-dissociation type is raised. In the case ofamino acid reacting with amino acid ester or amide, a velocity control is carried out, in which the velocity to produce the peptides from the acyl intermediates is raised and the velocity of the ester hydrolysis is slowed down. Examples of synthesis of tasty oligopeptides include, for example, the precursor in manufacturing artificial sweetener, aspartyl-phenylalanine methyl, as well as synthesis in an aqueous solution using special enzymes or in an organic solvent, and synthesis of other acidic amino acid oligomers. 24 refs., 2 figs.

  2. Laser photolysis study of anthraquinone in binary mixtures ofionic liquid [bmim][PF6] and organic solvent

    Directory of Open Access Journals (Sweden)

    Side Yao

    2006-12-01

    Full Text Available Photochemical properties of the ionic liquid (RTIL 1-butyl-3-methylimidazoliumhexafluorophosphate [bmim][PF6] and its binary mixed solutions with organic solvent(DMF and MeCN were investigated by laser photolysis at an excitation wavelength of 355nm, using anthraquinone (AQ as a probe molecule. It was indicated that the triplet excitedstate of AQ (3AQ* can abstract hydrogen from [bmim][PF6]. Moreover, along with thechange of the ratio of RTIL and organic solvent, the reaction rate constant changes regularly.Critical points were observed at volume fraction VRTIL = 0.2 for RTIL/MeCN and VRTIL =0.05 for RTIL/DMF. For both systems, before the critical point, the rate constant increasesrapidly with increasing VRTIL; however, it decreases obviously with VRTIL after the criticalpoint. We conclude that the concentration dependence is dominant at lower VRTIL, while theviscosity and phase transformation are dominant at higher VRTIL for the effect of ionic liquidon the decay of rate constant.

  3. Effect of Organic Solvents in Preparation of Silica-Based Chemical Gel Decontaminates for Decontamination of Nuclear Facilities

    International Nuclear Information System (INIS)

    Yoon, Suk Bon; Jung, Chong Hun; Kim, Chang Ki; Choi, Byung Seon; Lee, Kune Woo; Moon, Jei Kwon

    2011-01-01

    Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment such as stainless steel components, other iron-based steel and alloys, metal surfaces, structural materials and so on. Chemical decontamination technology in particular is a highly effective method to remove the radioactive contamination through a chemical dissolution or a redox reaction. However, this method has the serious drawback due to the generation of large amounts of the radioactive liquid wastes. Recently, a few literatures have been reported for the preparation of the chemical gel decontaminants to reduce the amount of the radioactive liquid wastes and to enhance the decontamination efficiency through increasing the contact time between the gels and the radioactive contaminants. In the preparation of the chemical gels, the control of the viscosity highly depends on the amount of a coviscosifier used among the components of the chemical gels consisted of a viscosifier, a coviscosifier, and a chemical decontaminant. In this works, a new effective method for the preparation of the chemical gel was investigated by introducing the organic solvents. The mixture solution of the coviscosifier and organic solvent was more effective in the control of the viscosity compared with that of the coviscosifier only in gels. Furthermore, the decontamination efficiency of the chemical gels measured by using the multi-channel analyzer (MCA) showed the high decontamination factor for Co-60 and Cs-137 contaminated on the surface of the stainless steel 304

  4. Determination of basicity of neutral organic phosphorus extractants in nonpolar solvents by the 31P NMR method

    International Nuclear Information System (INIS)

    Yakshin, V.V.; Meshcheryakov, N.M.; Il'in, E.G.; Ignatov, M.E.; Laskorin, B.N.

    1984-01-01

    The variant of the NMR method application is developed for quantitative description of acidic-basic properties of neutral organic phosphorus extractants, R 3 P--O (NPE), in non-polar organic solvents. For the NPE basicity determination the dependence of the chemical shift value in NMR 31 P spectra of 0.1 M NPE solutions in the dodecane on sulfuric acid acitivity in aqueous phase at 0-12 M acidity is studied. The linear equation relating NPE basicity and electronic structure of these compounds expressed through the sum: of Kabachnik reaction constants is derived. Linear dependences between the NPE basicity value in dodecane and NPE basicity in nitromethane as well as enthalpies of complexes formation with charge transport with standard acid-iodine in heptane, enthalpies of hydrogen complexes formation with phenol and water have been found

  5. Solvent effects on the adsorption and self-organization of Mn12 on Au(111).

    Science.gov (United States)

    Pineider, Francesco; Mannini, Matteo; Sessoli, Roberta; Caneschi, Andrea; Barreca, Davide; Armelao, Lidia; Cornia, Andrea; Tondello, Eugenio; Gatteschi, Dante

    2007-11-06

    A sulfur-containing single molecule magnet, [Mn12O12(O2CC6H4SCH3)16(H2O)4], was assembled from solution on a Au(111) surface affording both submonolayer and monolayer coverages. The adsorbate morphology and the degree of coverage were inspected by scanning tunneling microscopy (STM), while X-ray photoelectron spectroscopy (XPS) allowed the determination of the chemical nature of the adsorbate on a qualitative and quantitative basis. The properties of the adsorbates were found to be strongly dependent on the solvent used to dissolve the magnetic complex. In particular, systems prepared from tetrahydrofuran solutions gave arrays of isolated and partially ordered clusters on the gold substrate, while samples prepared from dichloromethane exhibited a homogeneous monolayer coverage of the whole Au(111) surface. These findings are relevant to the optimization of magnetic addressing of single molecule magnets on surfaces.

  6. Size controlled synthesis of Co nanoparticles by combination of organic solvent and surfactant

    International Nuclear Information System (INIS)

    Chen Yong; Liew, K.Y.; Li Jinlin

    2009-01-01

    Co particles were synthesized with mean particle sizes in the range of 3.2-171.4 nm in ambient atmosphere by reduction of cobalt salt with sodium borohydride as the reducing reagent, a combination of alcohols as solvents and a triblock copolymer P123 (EO 20 PO 70 EO 20 ) as the surfactant. The particle size and its distribution were controlled by varying the synthesis parameters such as the viscosity of the medium, the amount of alcohols or P123 in the reaction system. FT-IR and X-ray photoelectron spectroscopy (XPS) measurements confirmed the interaction between the oxygen atoms of P123 and Co 2+ or Co 0 . Detailed surface analyses by XPS and HRTEM revealed that the synthesized particles consisted of Co 0 metal surrounded by amorphous CoO, Co 2 B and chemisorbed P123.

  7. Density and speed of sound of lithium bromide with organic solvents: Measurement and correlation

    Energy Technology Data Exchange (ETDEWEB)

    Zafarani-Moattar, Mohammed Taghi [Department of Physical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of); Research Institute of Fundamental Sciences, Tabriz 51664 (Iran, Islamic Republic of)], E-mail: zafarani47@yahoo.com; Shekaari, Hemayat [Department of Physical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of); Research Institute of Fundamental Sciences, Tabriz 51664 (Iran, Islamic Republic of)

    2007-12-15

    Densities, {rho}, and speed of sound, u, of the solutions of LiBr with non-aqueous solvents (methanol, ethanol, 2-propanol, acetone, and acetonitrile) having a wide range of dielectric constants were measured at T = 298.15 K. Also, these measurements were made for the system (LiBr + N,N-dimethylacetamide) at T = 323.15 K. For the investigated systems, the limiting values for apparent molar volume, V{sub {phi}}{sup 0}, and the apparent molar isentropic compressibility, {kappa}{sub {phi}}{sup 0}, were obtained from the Redlich-Mayer and an abbreviated form of the Pitzer equations. The Pitzer and NRTL equations were satisfactorily used for the correlation of apparent molar volumes, V{sub {phi}}, and the apparent molar isentropic compressibility, {kappa}{sub {phi}}, values of the studied systems.

  8. Ligand isotopic exchange of tris(acetylacetonato)germanium(IV) perchlorate in organic solvents

    International Nuclear Information System (INIS)

    Nagasawa, Akira; Saito, Kazuo

    1978-01-01

    The ligand isotopic exchange between tris(acetylacetonato)germanium(IV) perchlorate and acetylacetone[ 14 C] has been studied in 1,1,2,2-tetrachloroethane (TCE), nitromethane (NM), and acetonitrile (AN), at 100 - 120 0 C. In these solvents, the rate formula was R = k[H 2 O][complex]; the concentrations of the complex, free ligand, and water in solution were in the ranges from 0.01 to 0.1 mol dm -3 . The activation enthalpies and entropies for the k's are 105, 98, and 90 kJ mol -1 ; and -25, -53, and -69 JK -1 mol -1 , in TCE, NM, and AN, respectively. Influence of acid and base concentrations, and deuterium isotope effect on the rate in AN suggest that the rate controlling step of the exchange is governed by the ease of the proton transfer between the leaving and the incoming acac - in an intermediate. (auth.)

  9. Enhancement of Palmarumycin C12 and C13 Production by the Endophytic Fungus Berkleasmium sp. Dzf12 in an Aqueous-Organic Solvent System

    OpenAIRE

    Mou, Yan; Xu, Dan; Mao, Ziling; Dong, Xuejiao; Lin, Fengke; Wang, Ali; Lai, Daowan; Zhou, Ligang; Xie, Bingyan

    2015-01-01

    The endophytic fungus Berkleasmium sp. Dzf12, isolated from Dioscorea zingiberensis, was found to produce palmarumycins C12 and C13 which possess a great variety of biological activities. Seven biocompatible water-immiscible organic solvents including n-dodecane, n-hexadecane, 1-hexadecene, liquid paraffin, dibutyl phthalate, butyl oleate and oleic acid were evaluated to improve palmarumycins C12 and C13 production in suspension culture of Berkleasmium sp. Dzf12. Among the chosen solvents bot...

  10. Application of nanofiltration to the treatment of uranium mill effluents

    International Nuclear Information System (INIS)

    Macnaughton, S.J.; McCulloch, J.K.; Marshall, K.; Ring, R.J.

    2002-01-01

    Nanofiltration is widely used in water treatment due to the lower energy requirements and higher yields than reverse osmosis. Separation characteristics are dependent on both the molecular size and charge of the dissolved species in the feed solution as well as membrane properties. In this investigation the potential of nanofiltration to remove dissolved species from uranium mill effluent has been studied. The background behind the application is discussed and the results of the first testwork programme are presented. An initial screening of seventeen commercially available membranes was completed and it was found that uranium rejections of greater than 75% were consistently achieved. Selected membranes also showed potential for the separation of radium, sulfate and manganese. (author)

  11. Optimization of physical factors affecting the production of thermo-stable organic solvent-tolerant protease from a newly isolated halo tolerant Bacillus subtilis strain Rand

    Directory of Open Access Journals (Sweden)

    Salleh Abu

    2009-04-01

    Full Text Available Abstract Background Many researchers have reported on the optimization of protease production; nevertheless, only a few have reported on the optimization of the production of organic solvent-tolerant proteases. Ironically, none has reported on thermostable organic solvent-tolerant protease to date. The aim of this study was to isolate the thermostable organic solvent-tolerant protease and identify the culture conditions which support its production. The bacteria of genus Bacillus are active producers of extra-cellular proteases, and the thermostability of enzyme production by Bacillus species has been well-studied by a number of researchers. In the present study, the Bacillus subtilis strain Rand was isolated from the contaminated soil found in Port Dickson, Malaysia. Results A thermostable organic solvent-tolerant protease producer had been identified as Bacillus subtilis strain Rand, based on the 16S rRNA analysis conducted, as well as the morphological characteristics and biochemical properties. The production of the thermostable organic solvent-tolerant protease was optimized by varying various physical culture conditions. Inoculation with 5.0% (v/v of (AB600 = 0.5 inoculum size, in a culture medium (pH 7.0 and incubated for 24 h at 37°C with 200 rpm shaking, was the best culture condition which resulted in the maximum growth and production of protease (444.7 U/ml; 4042.4 U/mg. The Rand protease was not only stable in the presence of organic solvents, but it also exhibited a higher activity than in the absence of organic solvent, except for pyridine which inhibited the protease activity. The enzyme retained 100, 99 and 80% of its initial activity, after the heat treatment for 30 min at 50, 55, and 60°C, respectively. Conclusion Strain Rand has been found to be able to secrete extra-cellular thermostable organic solvent-tolerant protease into the culture medium. The protease exhibited a remarkable stability towards temperature and organic

  12. Crystallization of an organic compound from an ionic liquid using carbon dioxide as anti-solvent

    NARCIS (Netherlands)

    Kroon, M.C.; Toussaint, V.A.; Shariati - Sarabi, A.; Florusse, L.J.; Spronsen, van J.; Witkamp, G.J.; Peters, C.J.

    2008-01-01

    In this paper the anti-solvency behavior of supercritical carbon dioxide (CO2) as a way to recover an organic compound from an ionic liquid by crystallization is explored. As an example, the conditions for crystallization of the organic compound methyl-(Z)-a-acetamido cinnamate (MAAC) from the ionic

  13. Phase equilibria of didecyldimethylammonium nitrate ionic liquid with water and organic solvents

    International Nuclear Information System (INIS)

    Domanska, Urszula; Lugowska, Katarzyna; Pernak, Juliusz

    2007-01-01

    The phase diagrams for binary mixtures of an ammonium ionic liquid, didecyldimethylammonium nitrate, [DDA][NO 3 ], with: alcohols (propan-1-ol, butan-1-ol, octan-1-ol, and decan-1-ol): hydrocarbons (toluene, propylbenzene, hexane, and hexadecane) and with water were determined in our laboratory. The phase equilibria were measured by a dynamic method from T 220 K to either the melting point of the ionic liquid, or to the boiling point of the solvent. A simple liquidus curve in a eutectic system was observed for [DDA][NO 3 ] with: alcohols (propan-1-ol, butan-1-ol, and octan-1-ol); aromatic hydrocarbons (toluene and propylbenzene) and with water. (Solid + liquid) equilibria with immiscibility in the liquid phase were detected with the aliphatic hydrocarbons heptane and hexadecane and with decan-1-ol. (Liquid + liquid) equilibria for the system [DDA][NO 3 ] with hexadecane was observed for the whole mole fraction range of the ionic liquid. The observation of the upper critical solution temperature in binary mixtures of ([DDA][NO 3 ] + decan-1-ol, heptane, or hexadecane) was limited by the boiling temperature of the solvent. Characterisation and purity of the compounds were determined by elemental analysis, water content (Fisher method) and differential scanning microcalorimetry (d.s.c.) analysis. The d.s.c. method of analysis was used to determine melting temperatures and enthalpies of fusion. The thermal stability of the ionic liquid was resolved by the thermogravimetric technique-differential thermal analysis (TG-DTA) technique over a wide temperature range from (200 to 780) K. The thermal decomposition temperature of 50% of the sample was greater than 500 K. The (solid + liquid) phase equilibria, curves were correlated by means of different G Ex models utilizing parameters derived from the (solid + liquid) equilibrium. The root-mean-square deviations of the solubility temperatures for all calculated data are dependent upon the particular system and the particular

  14. Influence of organic solvents on interfacial water at surfaces of silica gel and partially silylated fumed silica

    International Nuclear Information System (INIS)

    Turov, V.V.; Gun'ko, V.M.; Tsapko, M.D.; Bogatyrev, V.M.; Skubiszewska-Zieba, J.; Leboda, R.; Ryczkowski, J.

    2004-01-01

    The effects of organic solvents (dimethylsulfoxide-d 6 (DMSO-d 6 ), chloroform-d, acetone-d 6 , and acetonitrile-d 3 ) on the properties of interfacial water at surfaces of silica gel Si-40 and partially silylated fumed silica A-380 were studied by means of the 1 H NMR spectroscopy with freezing-out of adsorbed water at 180 1 H NMR investigations were also analysed on the basis of the structural characteristics of silicas and quantum chemical calculations of the chemical shifts δ H and solvent effects. DMSO-d 6 and acetonitrile-d 3 are poorly miscible with water in silica gel pores in contrast to the bulk liquids. DMSO-d 6 and chloroform-d affect the structure of the interfacial water weaker than acetone-d 6 and acetonitrile-d 3 at amounts of liquids greater than the pore volume. Acetone-d 6 and acetonitrile-d 3 can displace water from pores under this condition. The chemical shift of protons in water adsorbed on silica gel is 3.5-6.5 ppm, which corresponds to the formation of two to four hydrogen bonds per molecule. Water adsorbed on partially silylated fumed silica has two 1 H NMR signals at 5 and 1.1-1.7 ppm related to different structures (droplets and small clusters) of the interfacial water

  15. Model of twelve properties of a set of organic solvents with graph-theoretical and/or experimental parameters.

    Science.gov (United States)

    Pogliani, Lionello

    2010-01-30

    Twelve properties of a highly heterogeneous class of organic solvents have been modeled with a graph-theoretical molecular connectivity modified (MC) method, which allows to encode the core electrons and the hydrogen atoms. The graph-theoretical method uses the concepts of simple, general, and complete graphs, where these last types of graphs are used to encode the core electrons. The hydrogen atoms have been encoded by the aid of a graph-theoretical perturbation parameter, which contributes to the definition of the valence delta, delta(v), a key parameter in molecular connectivity studies. The model of the twelve properties done with a stepwise search algorithm is always satisfactory, and it allows to check the influence of the hydrogen content of the solvent molecules on the choice of the type of descriptor. A similar argument holds for the influence of the halogen atoms on the type of core electron representation. In some cases the molar mass, and in a minor way, special "ad hoc" parameters have been used to improve the model. A very good model of the surface tension could be obtained by the aid of five experimental parameters. A mixed model method based on experimental parameters plus molecular connectivity indices achieved, instead, to consistently improve the model quality of five properties. To underline is the importance of the boiling point temperatures as descriptors in these last two model methodologies. Copyright 2009 Wiley Periodicals, Inc.

  16. Isolation, production, purification and characterization of an organic-solvent-thermostable alkalophilic cellulase from Bacillus vallismortis RG-07.

    Science.gov (United States)

    Gaur, Rajeeva; Tiwari, Soni

    2015-03-19

    The rising concerns about the scarcity of fossil fuels, the emission of green house gasses and air pollution by incomplete combustion of fossil fuel have also resulted in an increasing focus on the use of cellulases to perform enzymatic hydrolysis of the lignocellulosic materials for the generation of bioethanol. The aim of this study was to isolate a potential thermo-solvent tolerant cellulase producing bacterium from natural resources, and then applied for purification and characterization. The purified enzyme was to be accessible for the bioethanol production as well as industrial exploitation (discuss in our next study). It is the first instance when thermo-solvent tolerant cellulase producing bacterium was isolated from soil sample. The culture was identified as Bacillus vallismortis RG-07 by 16S rDNA sequence analysis. Bacillus vallismortis RG-07 reported maximum cellulase production from sugarcane baggase (4105 U ml(-1)) used as agro-waste carbon source. The cellulase enzyme produced by the Bacillus sp. was purified by (NH4)2SO4 precipitation, ion exchange and gel filtration chromatography, with overall recovery of 28.8%. The molecular weight of purified cellulase was 80 kDa as revealed by SDS-PAGE and activity gel analysis. The optimum temperature and pH for enzyme activity was determined as 65°C and 7.0 and it retained 95 and 75% of activity even at 95°C, and 9.0 respectively. The enzyme activity was enhanced in the presence of organic solvents (30%) n-dodecane, iso-octane, n-decane, xylene, toluene, n-haxane, n-butanol, and cyclohexane, after prolonged incubation (7 days). The enzyme activity was also stimulated by Ca(2+), mercaptoethanol, Tween-60, and Sodium hypochloride whereas strongly inhibited by Hg. Kinetic analysis of purified enzyme showed the Km and Vmax to be 1.923 mg ml(-1) and 769.230 μg ml(-1) min(-1), respectively. The unique property of solvent-thermostable-alkalophilic, nature proves the potential candidature of this isolate for

  17. Improved spectrophotometric analysis of fullerenes C60 and C70 in high-solubility organic solvents.

    Science.gov (United States)

    Törpe, Alexander; Belton, Daniel J

    2015-01-01

    Fullerenes are among a number of recently discovered carbon allotropes that exhibit unique and versatile properties. The analysis of these materials is of great importance and interest. We present previously unreported spectroscopic data for C60 and C70 fullerenes in high-solubility solvents, including error bounds, so as to allow reliable colorimetric analysis of these materials. The Beer-Lambert-Bouguer law is found to be valid at all wavelengths. The measured data were highly reproducible, and yielded high-precision molar absorbance coefficients for C60 and C70 in o-xylene and o-dichlorobenzene, which both exhibit a high solubility for these fullerenes, and offer the prospect of improved extraction efficiency. A photometric method for a C60/C70 mixture analysis was validated with standard mixtures, and subsequently improved for real samples by correcting for light scattering, using a power-law fit. The method was successfully applied to the analysis of C60/C70 mixtures extracted from fullerene soot.

  18. Parâmetros reacionais para a síntese enzimática do butirato de butila em solventes orgânicos Reactional parameters for enzymatic synthesis of butyl butyrate in organic solvent

    Directory of Open Access Journals (Sweden)

    Heizir F. CASTRO

    1997-12-01

    Full Text Available A síntese orgânica catalisada por enzimas envolve um mecanismo complexo dependente do tipo de substrato, enzima, solvente orgânico e teor de água no meio reacional. Neste trabalho foi estudado a influência de alguns desses parâmetros no rendimento da esterificação do butanol com ácido butírico, utilizando uma preparação enzimática comercial de lipase. A polaridade e natureza do solvente, bem como a razão molar entre o butanol e ácido butírico, foram considerados os fatores que mais influenciaram o desenvolvimento dessa síntese enzimática.The organic synthesis catalyzed by enzymes is a complex function of substrate concentration, water concentration in the liquid phase, enzyme and organic solvent properties. In this work the influence of some parameters on the esterification of butanol with butyric acid was investigated, using a commercial lipase preparation. The polarity and nature of the solvent and also the substrate mole ratios played an important role in the performance of this enzymatic synthesis.

  19. Instrument for Solvent Extraction and Analysis (ISEE) of Organics from Regolith Simulant Using Supercritical Fluid Extraction and Chromatography

    Science.gov (United States)

    Franco, Carolina; Hintze, Paul E.

    2017-01-01

    ISEE is an instrument with the potential to perform extractions from regolith found on the surface of asteroids and planets, followed by characterization and quantitation of the extracts using supercritical fluid extraction (SFE) and chromatography (SFC). SFE is a developed technique proven to extract a wide range of organic compounds. SFC is similar to High Performance Liquid Chromatography (HPLC) but has the advantage of performing chiral separations without needing to derivatize the chiral compounds. CO2 will be the solvent for both stages as it is readily available in the Mars atmosphere. ISEE will capture CO2 from the environment, and use it for SFE and SFC. If successful, this would allow ISEE to perform analysis of organic compounds without using consumables. This paper will present results on a preliminary, proof-of-principle effort to use SFE and SFC to extract and analyze lunar regolith simulant spiked with organic compounds representing a range of organics that ISEE would expect to characterize. An optimization of variables for the extraction of the organics from the spiked regolith was successfully developed, using 138 bar pressure and 40 C temperature. The extraction flow rate was optimized at 2% SLPM with 30% methanol modifier. The extractions were successful with a value of 77.3+/- 0.9% of organics extracted. However, the recovery of organics after the extraction was very low with only 48.5+/-14.2%. Moreover, three columns were selected to analyze multiple samples at a time; two of them are Viridis HSS C18 SB and Torus DIOL, and the third column, specific for chiral separations, has not yet been selected yet.

  20. Solvents in membrane synthesis and their effect on NF/RO performance: from conventional organic solvents to ionic liquids:Solventen in membraansynthese en hun effect op NF/RO performantie: van conventionele organische solventen naar ionische vloeistoffen

    OpenAIRE

    Mariën, Hanne

    2017-01-01

    Membrane technology has grown significantly over the last decades and is used in a broad range of applications nowadays. Nanofiltration (NF) and reverse osmosis (RO) are applied for the separation of low molecular weight components (< 1000 Da) and salts from the feed stream. The main part of the commercial NF and RO membranes are either integrally skinned asymmetric (ISA) or interfacially polymerized thin film composite (TFC) membranes. Polyamide (PA) TFC membranes are the standard in aqueous...

  1. Organic solvent wetting properties of UV and plasma treated ZnO nanorods: printed electronics approach

    KAUST Repository

    Sliz, Rafal; Suzuki, Yuji; Nathan, Arokia; Myllyla, Risto; Jabbour, Ghassan E.

    2012-01-01

    Due to low manufacturing costs, printed organic solar cells are on the short-list of renewable and environmentally- friendly energy production technologies of the future. However, electrode materials and each photoactive layer require different

  2. PERTURBATION OF VOLTAGE-SENSITIVE Ca2+ CHANNEL FUNCTION BY VOLATILE ORGANIC SOLVENTS.

    Science.gov (United States)

    The mechanisms underlying the acute neurophysiological and behavioral effects of volatile organic compounds (VOCs) remain to be elucidated. However, the function of neuronal ion channels is perturbed by VOCs. The present study examined effects of toluene (TOL), trichloroethylene ...

  3. Metal dissolution kinetics in organic solvents using rotating ring-disc voltammetry. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    The effect of a two-phased liquid system - composed of geothermal brine and an organic heat transfer fluid - on the stability of materials used in the energy conversion system was investigated. The principle organic liquids used were isobutane and isopentane. The effects of relative fluid velocity on the corrosion behavior of representative construction materials, austenitic stainless steels, nickel, and copper alloy were determined using an autoclave incorporating a rotating ring-disc electrode. 2 refs., 20 figs. (ACR)

  4. In situ analysis of negative-tone resist pattern formation using organic-solvent-based developer process

    Science.gov (United States)

    Santillan, Julius Joseph; Yamada, Keisaku; Itani, Toshiro

    2014-01-01

    In situ resist “pattern formation” analysis during the development process using high-speed atomic force microscopy has been improved for application not only for conventional aqueous 0.26 N tetramethylammonium hydroxide (aq. TMAH), but also organic solvent n-butyl acetate (nBA) developers. Comparative investigations of resist dissolution in these developers, using the same resist material (hybrid of polyhydroxystyrene and methacrylate), showed a grainlike, uniform dissolution of the “unexposed resist film” in nBA development and uneven dissolution of the “exposed resist film” in aq. TMAH development. These results suggest the importance of dissolution uniformity in further improving the resulting pattern line width roughness.

  5. Assessment of DNA damage in car spray painters exposed to organic solvents by the high-throughput comet assay.

    Science.gov (United States)

    Londoño-Velasco, Elizabeth; Martínez-Perafán, Fabián; Carvajal-Varona, Silvio; García-Vallejo, Felipe; Hoyos-Giraldo, Luz Stella

    2016-05-01

    Occupational exposure as a painter is associated with DNA damage and development of cancer. Comet assay has been widely adopted as a sensitive and quantitative tool for DNA damage assessment at the individual cell level in populations exposed to genotoxics. The aim of this study was to assess the application of the high-throughput comet assay, to determine the DNA damage in car spray painters. The study population included 52 car spray painters and 52 unexposed subjects. A significant increase in the %TDNA median (p  0.05). The results showed an increase in DNA breaks in car spray painters exposed to organic solvents and paints; furthermore, they demonstrated the application of high-throughput comet assay in an occupational exposure study to genotoxic agents.

  6. An off-on Fluorescent Sensor for Detecting a Wide Range of Water Content in Organic Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kanghyeon; Lee, Wanjin; Kim, Jae Nyoung; Kim, Hyung Jin [Chonnam National Univ., Gwangju (Korea, Republic of)

    2013-08-15

    This paper describes the synthesis and water sensing properties of a fluorescent photoinduced electron transfer (PET) sensor (5) with an extended operating sensing range. The 1,8-naphthalimide derivative (5) attached with a piperazine group and a carboxylic group was synthesized and applied as a fluorescent water sensor in water-miscible organic solvents. The fluorescence intensity of the dye 5 increased with increasing water content up to 80% (v/v) and the fluorescence intensities were enhanced 45-, 67- and 122-fold in aqueous EtOH, DMF and DMSO solutions, respectively. In aqueous acetone solution, the enhancement of the fluorescence intensities was somewhat lower (30-fold) but the response range was wider (0-90%, v/v)

  7. Effects of Organic Solvents on Indigo Formation by Pseudomonas sp. strain ST-200 Grown with High Levels of Indole.

    Science.gov (United States)

    Doukyu, N; Arai, T; Aono, R

    1998-01-01

    The indole tolerance level of Pseudomonas sp. strain ST-200 was 0.25 mg/ml. The level was raised to 4 mg/ml when diphenylmethane was added to the medium to 20% by volume. ST-200 grown in this two-phase culture system containing indole (1 mg/ml) and diphenylmethane (0.2 ml/ml) produced a water-soluble yellow pigment, isatic acid, and two water-insoluble and diphenylmethane-soluble pigments, blue indigo and purple indirubin. The amounts of the water-insoluble pigments corresponded to 0.5% (indigo) and 0.2% (indirubin) of the indole added to the medium. Of the conditions tried, indigo and indirubin were formed only when ST-200 was grown in the two-phase system overlaid with organic solvents with appropriate polarity.

  8. (/sup 13/N)ammonia in organic solvents; a potent synthetic precursor for /sup 13/N-labeling

    Energy Technology Data Exchange (ETDEWEB)

    Tominaga, Toshiyoshi; Hirobe, Masaaki; Suzuki, Kazutoshi; Inoue, Osamu; Irie, Toshiaki; Yamasaki, Toshio

    1987-01-01

    /sup 13/NH/sub 3/ in an organic solvent was prepared and its utility as a labeling precursor was studied. (/sup 13/N)adenine ((/sup 13/N)ADN), (/sup 13/N)nicotinamide ((/sup 13/N)NAM), (/sup 13/N)p-nitrophenyl carbamate ((/sup 13/N)NPC), and (/sup 13/N)L-glutamine ((/sup 13/N)Gln) were labeled utilizing this precursor. (/sup 13/N)ADN and (/sup 13/N)NAM were labeled in much better yields than from an aqueous solution of /sup 13/NH/sub 3/. (/sup 13/N)NPC and (/sup 13/N)Gln, which could not be labeled in an aqueous solution, were labeled in high radiochemical yields. Thus, the advantages of this precursor are the improvement of the labeling yield and the feasibility of labeling compounds unstable in aqueous conditions.

  9. In-tube electro-membrane extraction with a sub-microliter organic solvent consumption as an efficient technique for synthetic food dyes determination in foodstuff samples.

    Science.gov (United States)

    Bazregar, Mohammad; Rajabi, Maryam; Yamini, Yadollah; Asghari, Alireza; Abdossalami asl, Yousef

    2015-09-04

    A simple and efficient extraction technique with a sub-microliter organic solvent consumption termed as in-tube electro-membrane extraction (IEME) is introduced. This method is based upon the electro-kinetic migration of ionized compounds by the application of an electrical potential difference. For this purpose, a thin polypropylene (PP) sheet placed inside a tube acts as a support for the membrane solvent, and 30μL of an aqueous acceptor solution is separated by this solvent from 1.2mL of an aqueous donor solution. This method yielded high extraction recoveries (63-81%), and the consumption of the organic solvent used was only 0.5μL. By performing this method, the purification is high, and the utilization of the organic solvent, used as a mediator, is very simple and repeatable. The proposed method was evaluated by extraction of four synthetic food dyes (Amaranth, Ponceau 4R, Allura Red, and Carmoisine) as the model analytes. Optimization of variables affecting the method was carried out in order to achieve the best extraction efficiency. These variables were the type of membrane solvent, applied extraction voltage, extraction time, pH range, and concentration of salt added. Under the optimized conditions, IEME-HPLC-UV provided a good linearity in the range of 1.00-800ngmL(-1), low limits of detection (0.3-1ngmL(-1)), and good extraction repeatabilities (RSDs below 5.2%, n=5). It seems that this design is a proper one for the automation of the method. Also the consumption of the organic solvent in a sub-microliter scale, and its simplicity, high efficiency, and high purification can help one getting closer to the objectives of the green chemistry. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. INIBIÇÃO DE SALMONELLA POR EXTRATO DE ALECRIM (Rosmarinus officinalis: OBTENÇÃO DE EXTRATOS DE ALECRIM EM SOLVENTES ORGÂNICOS INHIBITION OF Salmonella BY ROSEMARY (Rosmarinus officinalis EXTRACTS: ORGANIC SOLVENTS ROSEMARY EXTRACT OBTENTION

    Directory of Open Access Journals (Sweden)

    Maria Célia Lopes Torres

    2007-09-01

    Full Text Available

    Com o objetivo de se obter um extrato de alecrim em solvente orgânico, a ser utilizado na inibição de Salmonella, em alimentos, foram testados quatro tipos de solventes, a saber: metanol, etanol, acetona e hexano. Na obtenção dos extratos foi adotada a técnica recomendada para determinação de lipídeos, conforme as NORMAS ANALÍTICAS DO INSTITUTO ADOLFO LUTZ (1976. A análise dos resultados evidenciou um excelente desempenho do metanol, não sendo contudo recomendada a utilização em produtos alimentares em virtude da sua toxidez. Também o etanol apresentou elevados índices de extração, sem os inconvenientes associados ao uso do metanol, sendo por isto o solvente indicado para a continuidade do estudo proposto.

    Aiming to obtain a rosemary extract in organic solvent to be used in Salmonella inhibition, in food, were tested four kinds of solvents, namely: methane alcohol, ethyl alcohol, acetone and hexane. It was used the recommended technique for lipids determination in extracts determination according to the analytic rules used by Instituto Adolfo Lutz. Analysis results showed an excellent performance for methane alcohol, but its use is not recommended in feed products due to its toxicity. Ethyl alcohol presented also elevated extraction indexes without inconvenients associated to methane alcohol use, by this reason being a solvent indicated for continuity to the proposed study.

  11. P1-11: Visual Function and Neurotoxic Symptoms Related to Exposure to Organic Solvents

    Directory of Open Access Journals (Sweden)

    Ingrid Jimenez Barbosa

    2012-10-01

    Full Text Available Aim: Exposure to Perchloroethylene (PERC, a solvent used in dry-cleaning, is associated with neurotoxicity and changes in colour vision (CV and contrast sensitivity (CS. However, PERCs' impact on other aspects of visual function (VF such as chromatic contrast sensitivity (CCS, glass pattern detection (GPP, visual search (VS, and global motion sensitivity (GMS remains unclear. This study compared VF and neurotoxicity in two populations at risk, dry-cleaners (cases from Colombia and Australia. Control groups of people with community levels of exposure to PERC were also assessed. Methods: A case-control study of VF in people who are working in the dry-cleaning industry for at least 1 year (n = 40 Colombia; n= 34 Australia with controls (n = 35 each site. VF measures assessed were CSF, CCS, the FM Hue 100 test, VS, GPP, and GMS. Neurotoxic symptoms were assessed using the Q16 modified version questionnaire. Results: Cases had poorer CCS, hue discrimination, GPP, GMS, and higher Q16 scores than controls (p < .05. There was no effect of country. CS function was poorer than controls (p < .05 for spatial frequencies≥0.50 cpd for Australian cases but for ≥1.0 cpd for Colombian cases. There were no significant differences between cases and controls for serial and parallel VS. Conclusion: Our CSF and CV findings indicate that the CS deficit extends to lower spatial frequencies. Furthermore we report a reduction in the detection of form, motion, and CCS. These deficits were associated with neurotoxic symptoms. Because VS was unaffected, it suggests that PERC affects lower order visual functions more severely than higher level cognition.

  12. Solubility and crystal nucleation in organic solvents of two polymorphs of curcumin.

    Science.gov (United States)

    Liu, Jin; Svärd, Michael; Hippen, Perschia; Rasmuson, Åke C

    2015-07-01

    Two crystal polymorphs of 1,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (curcumin) have been obtained by crystallization from ethanol (EtOH) solution. The polymorphs have been characterized by differential scanning calorimetry, infrared spectroscopy, and X-ray powder diffraction and shown to be the previously described forms I and III. The solubility of both polymorphs in EtOH and of one polymorph in ethyl acetate (EA) has been measured between 10°C and 50°C with a gravimetric method. Primary nucleation of curcumin from EtOH solution has been investigated in 520 constant temperature crystallization experiments in sealed, magnetically stirred vials under different conditions of supersaturation, temperature, and agitation rate. By a thermodynamic analysis of the melting data and solubility of form I, the solid-state activity is estimated from 10°C up to the melting point. The solubility is lower in EtOH than in EA, and in both solvents, a positive deviation from Raoult's law is observed. Form I has lower solubility than form III and is accordingly thermodynamically more stable over the investigated temperature interval. Extrapolation of solubility regression models indicates that there should be a low-temperature enantiotropic transition point, below which form I will be metastable. By slurry conversion experiments, it is established that this temperature is below -30°C. All nucleation experiments resulted in the stable form I. The induction time is observed to decrease with increasing agitation rate up to a certain point, and then increase with further increasing agitation rate; a trend previously observed for other compounds. By correlating the induction time data obtained at different supersaturation and temperature, the interfacial energy of form I in EtOH is estimated to be 3.0 mJ/m(2) . © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  13. The stability of high-Tc BSCCO/Ag superconducting microcomposites in water, some inorganic solutions and organic solvents

    International Nuclear Information System (INIS)

    Gao, W.; Chen, J.; Yang, C.O.; McNabb, D.; Sande, J. vander

    1992-01-01

    Bi(Pb)-Sr-Ca-Cu-O/Ag (BSCCO/Ag) superconducting microcomposites with zero-resistance temperatures from 102 to 108 K and critical current densities of ∝600 A/cm 2 at 77 K were produced by oxidation and annealling of metallic precursor alloys. The stabilities and degradation behavior of BSCCO/Ag specimens in various environments were studied by a combination of mass loss measurement, electrical transport measurement and microstructural observation. The environmental conditions used in the present work were moist air, distilled water, aqueous solutions of NaCl, NaOH and acetic acid, and organic solvents methanol and acetone. Although there is a general tendency toward a decrease in critical current density after a long exposure to most of the testing conditions, the specimens containing a high percent of Ag (≥70 wt.%) showed very little decrease in Tc and J c up to 200 days of exposure in moist air and distilled water, and up to 20 days in NaCl solution, methanol and acetone. It was found that the superconducting ''2223'' phase is stable in water, neutral solutions and the organic solvents, reacts very slowly with basic solutions, and dissolves rapidly in acidic solutions. Some non-superconducting Ca-rich oxides dissolve in water and neutral and basic solutions and therefore damage the connection of the superconducting grains in low-Ag containing specimens. The excellent stability of the BSCCO/Ag superconducting microcomposites containing high Ag provides an important advantage for their potential industrial application. (orig.)

  14. Organic Solvent-Free Fabrication of Durable and Multifunctional Superhydrophobic Paper from Waterborne Fluorinated Cellulose Nanofiber Building Blocks.

    Science.gov (United States)

    Baidya, Avijit; Ganayee, Mohd Azhardin; Jakka Ravindran, Swathy; Tam, Kam Chiu; Das, Sarit Kumar; Ras, Robin H A; Pradeep, Thalappil

    2017-11-28

    In view of a great demand for paper-based technologies, nonwettable fibrous substrates with excellent durability have drawn much attention in recent years. In this context, the use of cellulose nanofibers (CNFs), the smallest unit of cellulosic substrates (5-20 nm wide and 500 nm to several microns in length), to design waterproof paper can be an economical and smart approach. In this study, an eco-friendly and facile methodology to develop a multifunctional waterproof paper via the fabrication of fluoroalkyl functionalized CNFs in the aqueous medium is presented. This strategy avoids the need for organic solvents, thereby minimizing cost as well as reducing safety and environmental concerns. Besides, it widens the applicability of such materials as nanocellulose-based aqueous coatings on hard and soft substrates including paper, in large areas. Water droplets showed a contact angle of 160° (±2°) over these surfaces and rolled off easily. While native CNFs are extremely hydrophilic and can be dispersed in water easily, these waterborne fluorinated CNFs allow the fabrication of a superhydrophobic film that does not redisperse upon submersion in water. Incorporated chemical functionalities provide excellent durability toward mechanochemical damages of relevance to daily use such as knife scratch, sand abrasion, spillage of organic solvents, etc. Mechanical flexibility of the chemically modified CNF composed paper remains intact despite its enhanced mechanical strength, without additives. Superhydrophobicity induced excellent microbial resistance of the waterproof paper which expands its utility in various paper-based technologies. This includes waterproof electronics, currency, books, etc., where the integrity of the fibers, as demonstrated here, is a much-needed criterion.

  15. Polyimide Dielectric Layer on Filaments for Organic Field Effect Transistors: Choice of Solvent, Solution Composition and Dip-Coating Speed

    Directory of Open Access Journals (Sweden)

    Rambausek Lina

    2014-09-01

    Full Text Available In today’s research, smart textiles is an established topic in both electronics and the textile fields. The concept of producing microelectronics directly on a textile substrate is not a mere idea anymore and several research institutes are working on its realisation. Microelectronics like organic field effect transistor (OFET can be manufactured with a layered architecture. The production techniques used for this purpose can also be applied on textile substrates. Besides gate, active and contact layers, the isolating or dielectric layer is of high importance in the OFET architecture. Therefore, generating a high quality dielectric layer that is of low roughness and insulating at the same time is one of the fundamental requirements in building microelectronics on textile surfaces. To evaluate its potential, we have studied polyimide as a dielectric layer, dip-coated onto copper-coated polyester filaments. Accordingly, the copper-coated polyester filament was dip-coated from a polyimide solution with two different solvents, 1-methyl-2-pyrrolidone (NMP and dimethylformaldehyde. A variety of dip-coating speeds, solution concentrations and solvent-solute combinations have been tested. Their effect on the quality of the layer was analysed through microscopy, leak current measurements and atomic force microscopy (AFM. Polyimide dip-coating with polyimide resin dissolved in NMP at a concentration of 15w% in combination with a dip-coating speed of 50 mm/min led to the best results in electrical insulation and roughness. By optimising the dielectric layer’s properties, the way is paved for applying the subsequent semi-conductive layer. In further research, we will be working with the organic semiconductor material TIPS-Pentacene

  16. Mechanical properties of wood from Pinus sylvestris L. treated with Light Organic Solvent Preservative and with waterborne Copper Azole

    Directory of Open Access Journals (Sweden)

    A.M. Villasante

    2013-12-01

    Full Text Available Aim of study: To determine the effect on wood from Pinus sylvestris of treatment with preservatives on mechanical properties and to establish the relation between the penetration and compression strength.Area of study: SpainMaterial and Methods: 40 samples of defect-free wood from Pinus sylvestris L. were treated with Light Organic Solvent Preservative (Vacsol Azure WR 2601 and 50 with waterborne Copper Azole (Tanalith E 3492. 40 control samples were not treated (water or preservative. Mechanical resistance to static bending, modulus of elasticity and compression strength parallel to the grain were compared with untreated wood. Regression analysis between the penetration and compression strength parallel was done with the samples treated with waterborne preservative.Main results: The results indicate that the treated wood (with either product presents a statistically significant increase in mechanical resistance in all three mechanical characteristics. The results obtained differ from earlier studies carried out by other authors.There was no correlation between parallel compression strength and the degree of impregnation of the wood with waterborne Copper Azole . The most probable explanation for these results concerns changes in pressure during treatment.The use of untreated control samples instead of samples treated only with water is more likely to produce significant results in the mechanical resistance studies.Research highlights: Treated wood presents a statistically significant increase in MOE, modulus of rupture to static bending  and parallel compression strength.There was no correlation between parallel compression strength and the degree of impregnation with waterborne preservative.Keywords: Light Organic Solvent Preservative; MOE; parallel compression; static bending; waterborne Copper Azole; wood technology.

  17. Reclaiming agricultural drainage water with nanofiltration membranes: Imperial Valley, California, USA

    Science.gov (United States)

    Kharaka, Y.K.; Schroeder, R.A.; Setmire, J.G.; ,

    2003-01-01

    We conducted pilot-scale field experiments using nanofiltration membranes to lower the salinity and remove Se, As and other toxic contaminants from saline agricultural wastewater in the Imperial Valley, California, USA. Farmlands in the desert climate (rainfall - 7.4 cm/a) of Imperial Valley cover -200,000 ha that are irrigated with water (-1.7 km3 annually) imported from the Colorado River. The salinity (-850 mg/L) and concentration of Se (-2.5 ??g/L) in the Colorado River water are high and evapotranpiration further concentrates salts in irrigation drainage water, reaching salinities of 3,000-15,000 mg/L TDS and a median Se value of -30 ??g/L. Experiments were conducted with two commercially available nanofiltration membranes, using drainage water of varying composition, and with or without the addition of organic precipitation inhibitors. Results show that these membranes selectively remove more than 95% of Se, SO4, Mo, U and DOC, and -30% of As from this wastewater. Low percentages of Cl, NO3 and HCO3, with enough cations to maintain electrical neutrality also were removed. The product water treated by these membranes comprised more than 90% of the wastewater tested. Results indicate that the treated product water from the Alamo River likely will have less than 0.2 ??g/L Se, salinity of 300-500 mg/L TDS and other chemical concentrations that meet the water quality criteria for irrigation and potable use. Because acceptability is a major issue for providing treated wastewater to urban centers, it may be prudent to use the reclaimed water for irrigation and creation of lower salinity wetlands near the Salton Sea; an equivalent volume of Colorado River water can then be diverted for the use of increasing populations of San Diego and other urban centers in southern California. Nanofiltration membranes yield greater reclaimed-water output and require lower pressure and less pretreatment, and therefore are generally more cost effective than traditional reverse

  18. Analysis of larger than tetrameric poly(adenosine diphosphoribose) by a radioimmunoassay in nuclei separated in organic solvents

    International Nuclear Information System (INIS)

    Ferro, A.M.; Minaga, T.; Piper, W.N.; Kun, E.

    1978-01-01

    Antibodies were prepared against poly(adenosine diphosphoribose) of an average chain length of 40 adenosine diphosphoribose units by repeated injection of the polymer mixed with methylated albumin and adjuvants into rabbits. The antibody was present mainly in the 7 S fraction of the immunoglobulins. A membrane binding assay was developed, and its specificity determined for the detection of (adenosine diphosphoribose) (n>4) in organs. The method is suitable for the study of the variation of the polymer content of nuclei. The size recognition of the anti-poly(adenosine diphosphoribose) globulin fraction was the same for polymers composed of 4-40 adenosine diphosphoribose units, but smaller oligomers were not detectible. A quantitative extraction technique was developed and applied for radioimmunoassay of nuclear (adenosine diphosphoribose) n>4. Organs were freeze-clamped, freeze dried, broken into subcellular fragments in a colloid mill, and the nuclear fraction was subsequently separated in organic solvents in order to preserve the polymer. Nicotinamide and nicotinic acid, when administered in vivo, augmented the (adenosine diphosphoribose) (n>4) content of rat liver and heart. Tissues of infant pigeons contained larger quantities of (adenosine diphosphoribose) (n>4) than tissues of adult rates. (Auth.)

  19. Morphology versus vertical phase segregation in solvent annealed small molecule bulk heterojunction organic solar cells

    Czech Academy of Sciences Publication Activity Database

    Kovalenko, A.; Stoyanova, V.; Pospisil, J.; Zhivkov, I.; Fekete, Ladislav; Karashanova, D.; Kratochvílová, Irena; Vala, M.; Weiter, M.

    2015-01-01

    Roč. 2015, Oct (2015), s. 238981 ISSN 1110-662X R&D Projects: GA ČR(CZ) GA15-05095S; GA TA ČR TA04020156; GA MŠk LO1409 Institutional support: RVO:68378271 Keywords : organic solar cells Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.226, year: 2015

  20. Sol-gel immobilization of serine proteases for application in organic solvents

    NARCIS (Netherlands)

    van Unen, D.J.; Engbersen, Johannes F.J.; Reinhoudt, David

    2001-01-01

    The serine proteases α-chymotrypsin, trypsin, and subtilisin Carlsberg were immobilized in a sol-gel matrix and the effects on the enzyme activity in organic media are evaluated. The percentage of immobilized enzyme is 90% in the case of α-chymotrypsin and the resulting specific enzyme activity in

  1. Highly stable ni-m f6-nh2o/onpyrazine2(solvent)x metal organic frameworks and methods of use

    KAUST Repository

    Eddaoudi, Mohamed

    2016-10-13

    Provided herein are metal organic frameworks comprising metal nodes and N-donor organic ligands. Methods for capturing chemical species from fluid compositions comprise contacting a metal organic framework characterized by the formula [MaMbF6-n(O/H2O)w(Ligand)x(solvent)y]z with a fluid composition and capturing one or more chemical species from the fluid composition.

  2. Purification and characterization of an extracellular halophilic and organic solvent-tolerant amylopullulanase from a haloarchaeon, Halorubrum sp. strain Ha25.

    Directory of Open Access Journals (Sweden)

    Mostafa Fazeli

    2013-01-01

    Full Text Available Introduction: Halophiles, especially haloarchaea are one of the most important groups of extremophiles. Halophilic hydrolases have been studied worldwide and have been considered for biotechnology and industrial technologies. This study is the first report in amylopullulanase production in halophilic microorganisms.Materials and methods: A halophilic archaeon, Halorubrum sp. strain Ha25, produced extracellular halophilic organic solvent-tolerant amylopullulanase. The enzyme was purified using ethanol precipitation and anion exchange chromatography method. Molecular mass of purified enzyme was determined by SDS–PAGE method. After purification, the enzyme was characterized. To study the effects of organic solvents in the stability of the enzyme, the enzyme solution was incubated in the presence of various organic compounds and then, residual enzyme activity was measured. Mode of action of the enzyme was determined by thin-layer chromatography.Results: Molecular weight of the purified enzyme was estimated to be 140 kDa by SDS–PAGE method. Optimum temperature for amylolitic and pullulytic activities was 50 °C. Optimum pH for amylolitic activity was 7.0 and for pullulytic activity was 7.5. This enzyme was active over a wide range of concentrations (0-4.5 M of NaCl. The effect of organic solvents on the amylolitic and pullulytic activities showed that this enzyme was more stable in the presence of non-polar organic solvents than polar solvents. The enzyme solely hydrolyzed pullulan and soluble starch to glucose.Discussion and conclusion: Halorubrum sp. strain Ha25 produces thermophilic and extremely halophilic amylopullulanase. The catalytic function under multi extreme condition of high temperature, high salinity, and low water activity might possess biotechnological and commercial values such as treatment waste solutions with starch residues, high salt content and solvents.

  3. Solvent extraction of indium and gallium complexes with bromopyrogallol red by mixed extractants containing chloroform, a polar organic solvent and monocarboxylic acids

    International Nuclear Information System (INIS)

    Pyatnitskij, I.V.; Lysenko, O.V.; Kolomiets, L.L.

    1987-01-01

    Solvent extraction of indium and gallium complexes with bromopyragallol red (BPR) has been studied using mixed extractants containing chloroform, capronic acid (HL) and 1-pentanol (S) (extractant 1), and chloroform, HL, S and propionic acid (extractant 2). The latter is more selectie and extracts only the indium complex. Optimal conditions have been found for the extraction of In-BRP complex (pH 6.3-6.5; C BPR 1.5x10 -4 M) its composition has been estimated and discussed

  4. Safety limits of half-mask cartridge respirators for organic solvent vapors

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Recent studies of the effective service life (safety limits) for typical half-mask cartridge respirators have shown these devices to be unsuitable for certain organic vapors, e.g., methanol, methylamine, vinyl chloride, and dichloromethane, because the effective service life is too short. For these vapors other forms of protection such as air-supplied respirators are recommended. The experimentally determined service life for many vapors is shorter--sometimes significantly shorter--than predicted by adsorption theory

  5. Vacuum-and-solvent-free fabrication of organic semiconductor layers for field-effect transistors

    Science.gov (United States)

    Matsushima, Toshinori; Sandanayaka, Atula S. D.; Esaki, Yu; Adachi, Chihaya

    2015-09-01

    We demonstrate that cold and hot isostatic pressing (CIP and HIP) is a novel, alternative method for organic semiconductor layer fabrication, where organic powder is compressed into a layer shape directly on a substrate with 200 MPa pressure. Spatial gaps between powder particles and the other particles, substrates, or electrodes are crushed after CIP and HIP, making it possible to operate organic field-effect transistors (OFETs) containing the compressed powder as the semiconductor. The CIP-compressed powder of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) had a hole mobility of (1.6 ± 0.4) × 10-2 cm2/Vs. HIP of C8-BTBT powder increased the hole mobility to an amorphous silicon-like value (0.22 ± 0.07 cm2/Vs) because of the growth of the C8-BTBT crystallites and the improved continuity between the powder particles. The vacuum and solution processes are not involved in our CIP and HIP techniques, offering a possibility of manufacturing OFETs at low cost.

  6. Vacuum-and-solvent-free fabrication of organic semiconductor layers for field-effect transistors

    Science.gov (United States)

    Matsushima, Toshinori; Sandanayaka, Atula S. D.; Esaki, Yu; Adachi, Chihaya

    2015-01-01

    We demonstrate that cold and hot isostatic pressing (CIP and HIP) is a novel, alternative method for organic semiconductor layer fabrication, where organic powder is compressed into a layer shape directly on a substrate with 200 MPa pressure. Spatial gaps between powder particles and the other particles, substrates, or electrodes are crushed after CIP and HIP, making it possible to operate organic field-effect transistors (OFETs) containing the compressed powder as the semiconductor. The CIP-compressed powder of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) had a hole mobility of (1.6 ± 0.4) × 10–2 cm2/Vs. HIP of C8-BTBT powder increased the hole mobility to an amorphous silicon-like value (0.22 ± 0.07 cm2/Vs) because of the growth of the C8-BTBT crystallites and the improved continuity between the powder particles. The vacuum and solution processes are not involved in our CIP and HIP techniques, offering a possibility of manufacturing OFETs at low cost. PMID:26416434

  7. Solvent-vapour-assisted pathways and the role of pre-organization in solid-state transformations of coordination polymers

    Directory of Open Access Journals (Sweden)

    James S. Wright

    2015-03-01

    Full Text Available A family of one-dimensional coordination polymers, [Ag4(O2C(CF22CF34(phenazine2(arenen]·m(arene, 1 (arene = toluene or xylene, have been synthesized and crystallographically characterized. Arene guest loss invokes structural transformations to yield a pair of polymorphic coordination polymers [Ag4(O2C(CF22CF34(phenazine2], 2a and/or 2b, with one- and two-dimensional architectures, respectively. The role of pre-organization of the polymer chains of 1 in the selectivity for formation of either polymorph is explored, and the templating effect of toluene and p-xylene over o-xylene or m-xylene in the formation of arene-containing architecture 1 is also demonstrated. The formation of arene-free phase 2b, not accessible in a phase-pure form through other means, is shown to be the sole product of loss of toluene from 1-tol·tol [Ag4(O2C(CF22CF34(phenazine2(toluene]·2(toluene, a phase containing toluene coordinated to Ag(I in an unusual μ:η1,η1 manner. Solvent-vapour-assisted conversion between the polymorphic coordination polymers and solvent-vapour influence on the conversion of coordination polymers 1 to 2a and 2b is also explored. The transformations have been examined and confirmed by X-ray diffraction, NMR spectroscopy and thermal analyses, including in situ diffraction studies of some transformations.

  8. Influence of organic solvents on interfacial water at surfaces of silica gel and partially silylated fumed silica

    Energy Technology Data Exchange (ETDEWEB)

    Turov, V.V.; Gun' ko, V.M.; Tsapko, M.D.; Bogatyrev, V.M.; Skubiszewska-Zieba, J.; Leboda, R.; Ryczkowski, J

    2004-05-15

    The effects of organic solvents (dimethylsulfoxide-d{sub 6} (DMSO-d{sub 6}), chloroform-d, acetone-d{sub 6}, and acetonitrile-d{sub 3}) on the properties of interfacial water at surfaces of silica gel Si-40 and partially silylated fumed silica A-380 were studied by means of the {sup 1}H NMR spectroscopy with freezing-out of adsorbed water at 180solvent effects. DMSO-d{sub 6} and acetonitrile-d{sub 3} are poorly miscible with water in silica gel pores in contrast to the bulk liquids. DMSO-d{sub 6} and chloroform-d affect the structure of the interfacial water weaker than acetone-d{sub 6} and acetonitrile-d{sub 3} at amounts of liquids greater than the pore volume. Acetone-d{sub 6} and acetonitrile-d{sub 3} can displace water from pores under this condition. The chemical shift of protons in water adsorbed on silica gel is 3.5-6.5 ppm, which corresponds to the formation of two to four hydrogen bonds per molecule. Water adsorbed on partially silylated fumed silica has two {sup 1}H NMR signals at 5 and 1.1-1.7 ppm related to different structures (droplets and small clusters) of the interfacial water.

  9. Process optimization for production and purification of a thermostable, organic solvent tolerant lipase from Acinetobacter sp. AU07

    Directory of Open Access Journals (Sweden)

    P. Gururaj

    Full Text Available ABSTRACT The purpose of this study was to isolate, purify and optimize the production conditions of an organic solvent tolerant and thermostable lipase from Acinetobacter sp. AU07 isolated from distillery waste. The lipase production was optimized by response surface methodology, and a maximum production of 14.5 U/mL was observed at 30 ºC and pH 7, using a 0.5% (v/v inoculum, 2% (v/v castor oil (inducer, and agitation 150 rpm. The optimized conditions from the shake flask experiments were validated in a 3 L lab scale bioreactor, and the lipase production increased to 48 U/mL. The enzyme was purified by ammonium sulfate precipitation and ion exchange chromatography and the overall yield was 36%. SDS-PAGE indicated a molecular weight of 45 kDa for the purified protein, and Matrix assisted laser desorption/ionization time of flight analysis of the purified lipase showed sequence similarity with GDSL family of lipases. The optimum temperature and pH for activity of the enzyme was found to be 50 ºC and 8.0, respectively. The lipase was completely inhibited by phenylmethylsulfonyl fluoride but minimal inhibition was observed when incubated with ethylenediaminetetraacetic acid and dithiothreitol. The enzyme was stable in the presence of non-polar hydrophobic solvents. Detergents like SDS inhibited enzyme activity; however, there was minimal loss of enzyme activity when incubated with hydrogen peroxide, Tween 80 and Triton X-100. The kinetic constants (Km and Vmax revealed that the hydrolytic activity of the lipase was specific to moderate chain fatty acid esters. The Vmax, Km and Vmax/Km ratio of the enzyme were 16.98 U/mg, 0.51 mM, and 33.29, respectively when 4-nitrophenyl palmitate was used as a substrate.

  10. Membrane-based osmotic heat engine with organic solvent for enhanced power generation from low-grade heat.

    Science.gov (United States)

    Shaulsky, Evyatar; Boo, Chanhee; Lin, Shihong; Elimelech, Menachem

    2015-05-05

    We present a hybrid osmotic heat engine (OHE) system that uses draw solutions with an organic solvent for enhanced thermal separation efficiency. The hybrid OHE system produces sustainable energy by combining pressure-retarded osmosis (PRO) as a power generation stage and membrane distillation (MD) utilizing low-grade heat as a separation stage. While previous OHE systems employed aqueous electrolyte draw solutions, using methanol as a solvent is advantageous because methanol is highly volatile and has a lower heat capacity and enthalpy of vaporization than water. Hence, the thermal separation efficiency of a draw solution with methanol would be higher than that of an aqueous draw solution. In this study, we evaluated the performance of LiCl-methanol as a potential draw solution for a PRO-MD hybrid OHE system. The membrane transport properties as well as performance with LiCl-methanol draw solution were evaluated using thin-film composite (TFC) PRO membranes and compared to the results obtained with a LiCl-water draw solution. Experimental PRO methanol flux and maximum projected power density of 47.1 L m(-2) h(-1) and 72.1 W m(-2), respectively, were achieved with a 3 M LiCl-methanol draw solution. The overall efficiency of the hybrid OHE system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages under conditions with and without heat recovery. The modeling results demonstrate higher OHE energy efficiency with the LiCl-methanol draw solution compared to that with the LiCl-water draw solution under practical operating conditions (i.e., heat recovery<90%). We discuss the implications of the results for converting low-grade heat to power.

  11. Electrochemical/chemical oxidation of bisphenol A in a four-electron/two-proton process in aprotic organic solvents

    International Nuclear Information System (INIS)

    Chan, Ya Yun; Yue, Yanni; Li, Yongxin; Webster, Richard D.

    2013-01-01

    Graphical abstract: - Highlights: • Bisphenol A undergoes a chemically irreversible voltammetric oxidation process. • Chemical oxidation was performed to overcome adsorption effects that cause electrode fouling. • A new product was isolated from chemical oxidation with 4 mol equiv. of the one-electron oxidant, NO + . • The oxidative mechanism was proposed to be a four-electron/two-proton process. - Abstract: The electrochemical behavior of bisphenol A (BPA) was examined using cyclic voltammetry, bulk electrolysis and chemical oxidation in aprotic organic solvents. It was found that BPA undergoes a chemically irreversible voltammetric oxidation process to form compounds that cannot be electrochemically converted back to the starting materials on the voltammetric timescale. To overcome the effects of electrode fouling during controlled potential electrolysis experiments, NO + was used as a one-electron chemical oxidant. A new product, hydroxylated bisdienone was isolated from the chemical oxidation of BPA with 4 mol equiv of NO + SbF 6 − in low water content CH 3 CN. The structure of the cation intermediate species was deduced and it was proposed that BPA is oxidized in a four-electron/two-proton process to form a relatively unstable dication which reacts quickly in the presence of water in acetonitrile (in a mechanism that is similar to phenols in general). However, as the water content of the solvent increased it was found that the chemical oxidation mechanism produced a nitration product in high yield. The findings from this study provide useful insights into the reactions that can occur during oxidative metabolism of BPA and highlight the possibility of the role of a bisdienone cation as a reactive metabolite in biological systems

  12. Membrane-Based Osmotic Heat Engine with Organic Solvent for Enhanced Power Generation from Low-Grade Heat

    Energy Technology Data Exchange (ETDEWEB)

    Shaulsky, E; Boo, C; Lin, SH; Elimelech, M

    2015-05-05

    We present a hybrid osmotic heat engine (OHE) system that uses draw solutions with an organic solvent for enhanced thermal separation efficiency. The hybrid OHE system produces sustainable energy by combining pressure-retarded osmosis (PRO) as a power generation stage and membrane distillation (MD) utilizing low-grade heat as a separation stage. While previous OHE systems employed aqueous electrolyte draw solutions, using methanol as a solvent is advantageous because methanol is highly volatile and has a lower heat capacity and enthalpy of vaporization than water. Hence, the thermal separation efficiency of a draw solution with methanol would be higher than that of an aqueous draw solution. In this study, we evaluated the performance of LiCl-methanol as a potential draw solution for a PRO-MD hybrid OHE system. The membrane transport properties as well as performance with LiCl methanol draw solution were evaluated using thin-film composite (TFC) PRO membranes and compared to the results obtained with a LiCl water draw solution. Experimental PRO methanol flux and maximum projected power density of 47.1 L m(-2) h(-1) and 72.1 W m(-2), respectively, were achieved with a 3 M LiCl-methanol draw solution. The overall efficiency of the hybrid OHE system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages under conditions with and without heat recovery. The modeling results demonstrate higher ORE energy efficiency with the LiCl methanol draw solution compared to that with the LiCl water draw solution under practical operating conditions (i.e., heat recovery <90%). We discuss the implications of the results for converting low-grade heat to power.

  13. Preferential solvation of ions in mixed solvents. 6: Univalent anions in aqueous organic solvents according to the inverse Kirkwood-Buff integral (IKBI) approach

    International Nuclear Information System (INIS)

    Marcus, Yizhak

    2007-01-01

    The inverse Kirkwood-Buff integral (IKBI) approach is applied to the preferential solvation of F - , Cl - , Br - , I - , and ClO 4 - in aqueous mixtures of the co-solvents (S) methanol (MeOH), ethanol (EtOH), t-butanol (t-BuOH), 1,2-ethanediol (EG), glycerol (Gly), acetone (Me 2 CO), acetonitrile (MeCN), formamide (FA), N,N-dimethylformamide (DMF), N,N,N',N',N'',N''-hexamethyl phosphoric triamide (HMPT), and dimethylsulfoxide (DMSO), as far as the relevant data exist in the literature. Fluoride anions are selectively solvated by the water up to large mole fractions (x S ≥ 0.4) of S = EtOH, t-BuOH, Me 2 CO, MeCN, and DMF, and up to lower contents (x S ∼ 0.1) of MeOH, EG, FA, and DMSO. The other anions are preferentially solvated by water to diminishing extent as their sizes become larger, and the largest ones show some preference for S in water-rich mixtures of MeOH and FA, whereas in aqueous Gly even chloride is preferentially solvated by the Gly. The competition between the co-solvent and the anion for the hydrogen bonds that water molecules donate is the main cause for the observed preferential solvation behaviour

  14. Preferential solvation of ions in mixed solvents. 6: Univalent anions in aqueous organic solvents according to the inverse Kirkwood-Buff integral (IKBI) approach

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, Yizhak [Department of Inorganic and Analytical Chemistry, Hebrew University of Jerusalem, Jerusalem 91904 (Israel)], E-mail: ymarcus@vms.huji.ac.il

    2007-10-15

    The inverse Kirkwood-Buff integral (IKBI) approach is applied to the preferential solvation of F{sup -}, Cl{sup -}, Br{sup -}, I{sup -}, and ClO{sub 4}{sup -} in aqueous mixtures of the co-solvents (S) methanol (MeOH), ethanol (EtOH), t-butanol (t-BuOH), 1,2-ethanediol (EG), glycerol (Gly), acetone (Me{sub 2}CO), acetonitrile (MeCN), formamide (FA), N,N-dimethylformamide (DMF), N,N,N',N',N'',N''-hexamethyl phosphoric triamide (HMPT), and dimethylsulfoxide (DMSO), as far as the relevant data exist in the literature. Fluoride anions are selectively solvated by the water up to large mole fractions (x{sub S} {>=} 0.4) of S = EtOH, t-BuOH, Me{sub 2}CO, MeCN, and DMF, and up to lower contents (x{sub S} {approx} 0.1) of MeOH, EG, FA, and DMSO. The other anions are preferentially solvated by water to diminishing extent as their sizes become larger, and the largest ones show some preference for S in water-rich mixtures of MeOH and FA, whereas in aqueous Gly even chloride is preferentially solvated by the Gly. The competition between the co-solvent and the anion for the hydrogen bonds that water molecules donate is the main cause for the observed preferential solvation behaviour.

  15. Solubility of metallic mercury in organic solvents; Solubilite du mercure metallique dans les solvants organiques; Rastvorimost' metallicheskoj rtuti v organicheskikh rastvoritelyakh; Solubilidad del mercurio metalico en solventes organicos

    Energy Technology Data Exchange (ETDEWEB)

    Klehr, E H; Voigt, A F [Institute for Atomic Research and Department of Chemistry, Iowa State University, Ames, IA (United States)

    1962-03-15

    The solubilities of metallic mercury at 25{sup o}C in the solvents carbon tetrachloride, 2, 2, 4-trimethylpentane, n-decane, benzene, toluene, nitrobenzene, chlorobenzene and bromobenzene have been determined by the use of Hg{sup 203} tracer. Measurements were made either by shaking mercury metal of known specific activity with the solvent, or by measuring the distribution coefficient of the metal between the solvent and water and combining this measurement with the solubility of mercury in water, or by both methods. Radioactivity was measured by counting precipitated samples with a GM counter or liquid aliquots with a well-type scintillator counter. All solubilities were in the range (4.6 to 16) x 10{sup -6} g atoms/l. For n-decane, toluene and chlorobenzene, the temperature dependence of the solubility was determined over the range 0 to 45{sup o}C. The Hildebrand-Scott theory of solubility has been applied to these systems for comparison. For the aliphatic hydrocarbons, the solubilities predicted by theory are within 35% of those observed, but for the other solvents, the predicted values are 4 to 18 times larger than those observed. Modification of the theory gives better agreement for some solvents but poorer agreement for others. Curves of log G (solubility) vs. 1/T were straight lines with slopes similar to those obtained from the Hildebrand-Scott theory but displaced from those curves. The slopes of the curves were used for the calculation of heats and entropies of solution. Entropies were also calculated from curves of log G vs. log T. The two sets of entropy values were in agreement with each other and were within one to four entropy units of the ideal entropies of mixing. (author) [French] Les auteurs ont determine la solubilite du mercure metallique a 25{sup o}C dans les solvants suivants: tetrachlorure de carbone, trimethylpentane 2, 2, 4, n-decane, benzene, toluene, nitrobenzene, chlorobenzene et bromobenzene en utilisant le mercure-203 comme

  16. Enhanced forward osmosis from chemically modified polybenzimidazole (PBI) nanofiltration hollow fiber membranes with a thin wall

    KAUST Repository

    Wang, Kai Yu; Yang, Qian; Chung, Tai-Shung; Rajagopalan, Raj

    2009-01-01

    To develop high-flux and high-rejection forward osmosis (FO) membranes for water reuses and seawater desalination, we have fabricated polybenzimidazole (PBI) nanofiltration (NF) hollow fiber membranes with a thin wall and a desired pore size via non-solvent induced phase inversion and chemically cross-linking modification. The cross-linking by p-xylylene dichloride can finely tune the mean pore size and enhance the salt selectivity. High water permeation flux and improved salt selectivity for water reuses were achieved by using the 2-h modified PBI NF membrane which has a narrow pore size distribution. Cross-linking at a longer time produces even a lower salt permeation flux potentially suitable for desalination but at the expense of permeation flux due to tightened pore sizes. It is found that draw solution concentration and membrane orientations are main factors determining the water permeation flux. In addition, effects of membrane morphology and operation conditions on water and salt transport through membrane have been investigated. © 2008 Elsevier Ltd. All rights reserved.

  17. Green Modification of Outer Selective P84 Nanofiltration (NF) Hollow Fiber Membranes for Cadmium Removal

    KAUST Repository

    Gao, Jie

    2015-10-26

    Outer-selective thin-film composite (TFC) hollow fiber membranes are normally made from interfacial polymerization of m-phenylenediamine (MPD) and trimesoyl chloride (TMC). However, the removal of excess MPD solution and the large consumption of alkane solvents are their technical bottlenecks. In this study, green methods to prepare the outer selective TFC hollow fiber membranes were explored by firstly modifying the membrane substrate with polyethyleneimine (PEI) and then by water soluble small molecules such as glutaraldehyde (GA) and epichlorohydrin (ECH). Using P84 polyimide as the substrate, not only do these modifications decrease substrate\\'s pore size, but also vary surface charge by making the membranes less positively charged. As a result, the resultant membranes have higher rejections against salts such as Na2SO4, NaCl and MgSO4. The PEI and then GA modified membrane has the best separation performance with a NaCl rejection over 90% and a pure water permeability (PWP) of 1.74±0.01 Lm−2bar−1h−1. It also shows an impressive rejection to CdCl2 (94%) during long-term stability tests. The CdCl2 rejection remains higher than 90% at operating temperatures from 5 to 60 °C. This study may provide useful insights for green manufacturing of outer-selective nanofiltration (NF) hollow fiber membranes.

  18. Enhanced forward osmosis from chemically modified polybenzimidazole (PBI) nanofiltration hollow fiber membranes with a thin wall

    KAUST Repository

    Wang, Kai Yu

    2009-04-01

    To develop high-flux and high-rejection forward osmosis (FO) membranes for water reuses and seawater desalination, we have fabricated polybenzimidazole (PBI) nanofiltration (NF) hollow fiber membranes with a thin wall and a desired pore size via non-solvent induced phase inversion and chemically cross-linking modification. The cross-linking by p-xylylene dichloride can finely tune the mean pore size and enhance the salt selectivity. High water permeation flux and improved salt selectivity for water reuses were achieved by using the 2-h modified PBI NF membrane which has a narrow pore size distribution. Cross-linking at a longer time produces even a lower salt permeation flux potentially suitable for desalination but at the expense of permeation flux due to tightened pore sizes. It is found that draw solution concentration and membrane orientations are main factors determining the water permeation flux. In addition, effects of membrane morphology and operation conditions on water and salt transport through membrane have been investigated. © 2008 Elsevier Ltd. All rights reserved.

  19. The Role of Concentration and Solvent Character in the Molecular Organization of Humic Acids

    Directory of Open Access Journals (Sweden)

    Martina Klučáková

    2016-10-01

    Full Text Available The molecular organization of humic acids in different aqueous solutions was studied over a wide concentration range (0.01–10 g·dm−3. Solutions of humic acids were prepared in three different media: NaOH, NaCl, and NaOH neutralized by HCl after dissolution of the humic sample. Potentiometry, conductometry, densitometry, and high resolution ultrasound spectrometry were used in order to investigate conformational changes in the humic systems. The molecular organization of humic acids in the studied systems could be divided into three concentration ranges. The rearrangements were observed at concentrations of ~0.02 g·dm−3 and ~1 g·dm−3. The first “switch-over point” was connected with changes in the hydration shells of humic particles resulting in changes in their elasticity. The compressibility of water in the hydration shells is less than the compressibility of bulk water. The transfer of hydration water into bulk water increased the total compressibility of the solution, reducing the ultrasonic velocity. The aggregation of humic particles and the formation of rigid structures in systems with concentrations higher than 1 g·dm−3 was detected.

  20. Interaction enthalpies of solid human serum albumin with water-dioxane mixtures: comparison with water and organic solvent vapor sorption

    International Nuclear Information System (INIS)

    Sirotkin, Vladimir A.; Faizullin, Djihanguir A.

    2004-01-01

    Enthalpy changes (ΔH tot ) on the immersion of dehydrated human serum albumin (HSA) into water-dioxane mixtures have been measured using a Setaram BT-2.15 calorimeter at 298 K. Thermodynamic activity of water was varied from 0 to 1. Calorimetric results are discussed together with the FTIR-spectroscopic data on water and organic solvent vapor adsorption/desorption isotherms on solid HSA. Dioxane sorption exhibits a pronounced hysteresis. Calorimetric and dioxane desorption dependencies consist of two parts. No dioxane sorption was observed in low water activity region (a w tot values are close to zero. At water activity about 0.5 the sharp exothermic drop of the interaction enthalpy values was observed. This exothermic drop is accompanied by the sharp increase in the amount of sorbed dioxane and additional water sorption (compared with that for pure water). Dioxane adsorption branch resembles a smooth curve. In this case, solid HSA binds more than 300 mol dioxane/mol HSA at low water activities. By using a water activity-based comparison we distinguished between dioxane-assisted and dioxane-competitive effect on water sorption. The obtained results demonstrate that the hydration 'history' of solid protein is an important factor that controls as the state of protein macromolecule as well as the sorption of low-molecular organic molecules

  1. Stabilization and activation of alpha-chymotrypsin in water-organic solvent systems by complex formation with oligoamines.

    Science.gov (United States)

    Kudryashova, Elena V; Artemova, Tatiana M; Vinogradov, Alexei A; Gladilin, Alexander K; Mozhaev, Vadim V; Levashov, Andrey V

    2003-04-01

    Formation of enzyme-oligoamine complexes was suggested as an approach to obtain biocatalysts with enhanced resistance towards inactivation in water-organic media. Complex formation results in broadening (by 20-40% v/v ethanol) of the range of cosolvent concentrations where the enzyme retains its catalytic activity (stabilization effect). At moderate cosolvent concentrations (20-40% v/v) complex formation activates the enzyme (by 3-6 times). The magnitude of activation and stabilization effects increases with the number of possible electrostatic contacts between the protein surface and the molecules of oligoamines (OA). Circular dichroism spectra in the far-UV region show that complex formation stabilizes protein conformation and prevents aggregation in water-organic solvent mixtures. Two populations of the complexes with different thermodynamic stabilities were found in alpha-chymotrypsin (CT)-OA systems depending on the CT/OA ratio. The average dissociation constants and stoichiometries of both low- and high-affinity populations of the complexes were estimated. It appears that it is the low-affinity sites on the CT surface that are responsible for the activation effect.

  2. Exceptional thermal stability and organic solvent tolerance of an esterase expressed from a thermophilic host

    DEFF Research Database (Denmark)

    Mei, Yuxia; Peng, Nan; Zhao, Shumiao

    2012-01-01

    , giving SisEstA. Upon Escherichia coli expression, only the thioredoxin-tagged EstA recombinant protein was soluble. The fusion protein was then purified, and removing the protein tag yielded EcSisEstA. Both forms of the thermophilic EstA enzyme were characterized. We found that SisEstA formed dimer...... that of EcSisEstA at 90°C. This indicated that thermophilic enzymes yielded from homologous expression should be better biocatalysts than those obtained from mesophilic expression.......A protein expression system recently developed for the thermophilic crenarchaeon Sulfolobus islandicus was employed to produce recombinant protein for EstA, a thermophilic esterase encoded in the same organism. Large amounts of protein were readily obtained by an affinity protein purification...

  3. Thermodynamic models for determination of solid–liquid equilibrium of the 6-benzyladenine in pure and binary organic solvents

    International Nuclear Information System (INIS)

    Li, Tao; Deng, Renlun; Wu, Gang; Gu, Pengfei; Hu, Yonghong; Yang, Wenge; Yu, Yemin; Zhang, Yuhao; Yang, Chen

    2017-01-01

    Highlights: • The solubility increased with increasing temperature. • Data were fitted using the modified Apelblat equation and other models in pure solvents. • Data were fitted using the modified Apelblat equation and other models in binary solvent mixture. - Abstract: Data on corresponding solid–liquid equilibrium of 6-benzyladenine in different solvents are essential for a preliminary study of industrial applications. In this paper, the solid–liquid equilibrium of 6-benzyladenine in methanol, ethanol, 1-butanol, acetone, acetonitrile, ethyl acetate, dimethyl formamide and tetrahydrofuran pure solvents and (dimethyl formamide + actone) mixture solvents was explored within the temperature range from (278.15 to 333.15) K under 0.1 MPa. For the temperature range investigated, the solubility of 6-benzyladenine in the solvents increased with increasing temperature. The solubility of 6-benzyladenine in dimethyl formamide is superior to other selected pure solvents. The modified Apelblat model, the Buchowski-Ksiazaczak λh model, and the ideal model were adopted to describe and predict the change tendency of solubility. Computational results showed that the modified Apelblat model has more advantages than the other two models. The solubility results were fitted using a modified Apelblat equation, a variant of the combined nearly ideal binary solvent/Redich-Kister (CNIBS/R-K) model, Jouyban-Acree model and Ma model in (dimethyl formamide + acetone) binary solvent mixture. Computational results showed that the modified Apelblat model is superior to the other equations.

  4. Determination and correlation thermodynamic models for solid–liquid equilibrium of the Nifedipine in pure and mixture organic solvents

    International Nuclear Information System (INIS)

    Wu, Gang; Hu, Yonghong; Gu, Pengfei; Yang, Wenge; Wang, Chunxiao; Ding, Zhiwen; Deng, Renlun; Li, Tao; Hong, Housheng

    2016-01-01

    Highlights: • The solubility increased with increasing temperature. • The data were fitted using the modified Apelblat equation in pure solvents. • The data were fitted using the CNIBS/R-K model in binary solvent mixture. - Abstract: Knowledge of thermodynamic parameters on corresponding solid-liquid equilibrium of nifedipine in different solvents is essential for a preliminary study of pharmaceutical engineering and industrial applications. In this paper, a gravimetric method was used to correct the solid-liquid equilibrium of nifedipine in methanol, ethanol, 1-butanol, acetone, acetonitrile, ethyl acetate and tetrahydrofuran pure solvents as well as in the (tetrahydrofuran + acetonitrile) mixture solvents at temperatures from 278.15 K to 328.15 K under 0.1 MPa. For the temperature range investigation, the solubility of nifedipine in the solvents increased with increasing temperature. The solubility of nifedipine in tetrahydrofuran is superior to other selected pure solvents. The modified Apelblat model, the Buchowski-Ksiazaczak λh model, and the ideal model were adopted to describe and predict the change tendency of solubility. Computational results showed that the modified Apelblat model stood out to be more suitable with the higher accuracy. The solubility values were fitted using a modified Apelblat model, a variant of the combined nearly ideal binary solvent/Redich-Kister (CNIBS/R-K) model and Jouyban-Acree model in (tetrahydrofuran + acetonitrile) binary solvent mixture. Computational results showed that the CNIBS/R-K model had more advantages than other models.

  5. Flexibility of Enzymes Suspended in Organic Solvents Probed by Time-Resolved Fluorescence Anisotropy. Evidence That Enzyme Activity and Enantioselectivity Are Directly Related to Enzyme Flexibility

    NARCIS (Netherlands)

    Broos, Jaap; Visser, Antonie J.W.G.; Engbersen, Johan F.J.; Verboom, Willem; Hoek, Arie van; Reinhoudt, David N.

    1995-01-01

    A time-resolved fluorescence anisotropy study on the molecular flexibility of active-site labeled anthraniloyl-α-chymotrypsin, dansylsubtilisin Carlsberg, and native subtilisin Carlsberg, suspended in organic solvents, is described. The internal rotational mobility of the fluorophore in the

  6. Organic solvent-induced changes in membrane geometry in human SH-SY5Y neuroblastoma cells - a common narcotic effect?

    NARCIS (Netherlands)

    Meulenberg, C.J.W.; de Groot, A.; Westerink, R.H.S.; Vijverberg, H.P.M.

    2016-01-01

    Exposure to organic solvents may cause narcotic effects. At the cellular level, these narcotic effects have been associated with a reduction in neuronal excitability caused by changes in membrane structure and function. In order to critically test whether changes in membrane geometry contribute to

  7. Optimal Concentration of Organic Solvents to be Used in the Broth Microdilution Method to Determine the Antimicrobial Activity of Natural Products Against Paenibacillus Larvae

    Directory of Open Access Journals (Sweden)

    Cugnata Noelia Melina

    2017-06-01

    Full Text Available American Foulbrood (AFB is a bacterial disease, caused by Paenibacillus larvae, that affects honeybees (Apis mellifera. Alternative strategies to control AFB are based on the treatment of the beehives with antimicrobial natural substances such as extracts, essential oils and/or pure compounds from plants, honey by-products, bacteria and moulds. The broth microdilution method is currently one of the most widely used methods to determine the minimum inhibitory concentration (MIC of a substance. In this regard, the fact that most natural products, due to their lipophilic nature, must be dissolved in organic solvents or their aqueous mixtures is an issue of major concern because the organic solvent becomes part of the dilution in the incubation medium, and therefore, can interfere with bacterial viability depending on its nature and concentration. A systematic study was carried out to determine by the broth microdilution method the MIC and the maximum non inhibitory concentration (MNIC against P. larvae of the most common organic solvents used to extract or dissolve natural products, i.e. ethanol, methanol, acetonitrile, n-butanol, dimethylsulfoxide, and acidified hydromethanolic solutions. From the MIC and MNIC for each organic solvent, recommended maximum concentrations in contact with P. larvae were established: DMSO 5% (v/v, acetonitrile 7.5% (v/v, ethanol 7.5% (v/v, methanol 12% (v/v, n-butanol 1% (v/v, and methanol-water-acetic acid (1.25:98.71:0.04, v/v/v.

  8. Investigation of the remaining major and trace elements in clean coal generated by organic solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Jie Wang; Chunqi Li; Kinya Sakanishi; Tetsuya Nakazato; Hiroaki Tao; Toshimasa Takanohashi; Takayuki Takarada; Ikuo Saito [National Institute Advanced Industrial Science and Technology (AIST), Ibaraki (Japan). Energy Technology Research Institute

    2005-09-01

    A sub-bituminous Wyodak coal (WD coal) and a bituminous Illinois No. 6 coal (IL coal) were thermally extracted with 1-methylnaphthalene (1-MN) and N-methyl-2-pyrrolidone (NMP) to produce clean extract. A mild pretreatment with acetic acid was also carried out. Major and trace inorganic elements in the raw coals and resultant extracts were determined by means of inductively coupled plasma optical emission spectrometry (ICP-OES), flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS), and cold vapor atomic absorption spectrometry (CV-AAS). It was found that the extraction with 1-MN resulted in 73-100% reductions in the concentration of Li, Be, V, Ga, As, Se, Sr, Cd, Ba, Hg, and Pb. The extraction with NMP yielded more extract than that with 1-MN, but it retained more organically associated major and trace metals in the extracts. In the extraction of WD coal with NMP, the acid pretreatment not only significantly enhanced the extraction yield but also significantly reduced the concentrations of alkaline earth elements such as Be, Ca, Mg, Sr, and Ba in the extract. In addition, the modes of occurrence of trace elements in the coals were discussed according to their extraction behaviors. 30 refs., 2 figs., 5 tabs.

  9. Exchange of organic solvents between the atmosphere and grass--the use of open top chambers.

    Science.gov (United States)

    Binnie, J; Cape, J N; Mackie, N; Leith, I D

    2002-02-21

    Volatile organic compounds (VOC) are of increasing environmental significance as a result of continually increasing volumes of traffic on European roads. An open-top chamber fumigation system has been devised to investigate how these contaminants transfer between the atmosphere and the ground, and how they partition between and within air-plant-soil systems. Variation in chamber temperature, solar radiation in the chamber and chamber flow rate were identified as factors that affected final air concentrations. These were assessed and quantified for all individual chambers used--effectively characterising each chamber. The real-life VOC concentrations generated were stable and readily reproducible. Grass exposed to benzene, toluene, 1,1,1-trichloroethane and tetrachloroethene, respectively, equilibrated in response to a change in air concentration within hours. The rate of equilibration in exposed grass in all cases was independent of air temperature. 1,1,1-Trichloroethane and tetrachloroethene appear to be biologically inert demonstrating a simple physico-chemical approach to equilibrium, however, benzene and toluene do not appear independent of plant metabolic activity. Aqueous solubility can account for all of the toluene and benzene in the fumigated plant material.

  10. Recovery of Ionic Liquids from aqueous solution by Nanofiltration

    OpenAIRE

    Fernández Dámaso, José Francisco

    2011-01-01

    The T-SAR methodology was combined with membrane characterization methods. An application of the combined approach was demonstrated with two commercial nanofiltration membranes and it was possible to successfully predict their performance for the recovery of ionic liquids from aqueous solution. Using model solutions of Pyr16 (CF3SO2)2N, it could be evidenced the formation of a new phase of ionic liquid during the concentration process. In this case, 66% of the ionic liquid was separated and t...

  11. Effect of Organic Solvents and Biologically Relevant Ions on the Light-Induced DNA Cleavage by Pyrene and Its Amino and Hydroxy Derivatives

    Directory of Open Access Journals (Sweden)

    Hongtao Yu

    2002-09-01

    Full Text Available Abstract: Polycyclic aromatic hydrocarbons (PAHs are a class of carcinogenic compounds that are both naturally and artificially produced. Many PAHs are pro-carcinogens that require metabolic activation. Recently, it has been shown that PAH can induce DNA single strand cleavage and formation of PAH-DNA covalent adduct upon irradiation with UVA light. The light-induced DNA cleavage parallels phototoxicity in one instance. The DNA photocleavage efficiency depends on the structure of the PAHs. This article reports the effect of both organic solvents and the presence of biologically relevant ions, Na+, Mg2+, Ca2+, K+, Fe3+, Cu2+, Zn+2, Mn2+, and I-, on the light-induced DNA cleavage by pyrene, 1-hydroxypyrene and 1-aminopyrene. Since both 1-hydroxypyrene (0.6 μM and 1-aminopyrene (6 μM dissolve well in the minimum organic solvents used (2% methanol, dimethylsulfoxide, and dimethylformamide, increasing the amount of the organic solvent resulted in the decrease of the amount of DNA single strand cleavage caused by the combination effect of 1-hydroxy or 1-aminopyrene and UVA light. The result with the less watersoluble pyrene shows that increase of the amount of the organic solvent can increase the amount of DNA single strand DNA photocleavage cause by the combination of pyrene and UVA light. Therefore, there are two effects by the organic solvents: (i to dissolve PAH and (ii to quench DNA photocleavage. The presence of Fe3+ and Zn2+ enhances, while the presence of Ca2+ and Mn2+ inhibits the DNA photocleavage caused by 1-aminopyrene and UVA light. Other metal ions have minimal effect. This means that the effect of ions on DNA photocleavage by PAHs is complex. The presence of KI enhances DNA photocleavage. This indicates that the triplet-excited state of 1-aminopyrene is involved in causing DNA cleavage

  12. The effect of solvent component on the discharge performance of Lithium-sulfur cell containing various organic electrolytes

    International Nuclear Information System (INIS)

    Kim, Seok; Jung, Yongju; Lim, Hong S.

    2004-01-01

    The effect of solvent component on the discharge performance of lithium-sulfur (Li/S) cell and the optimal composition of ternary electrolyte for the improved discharge performance of the cell have been investigated. The capacity value and capacity stability with cycle are dependent on the nature of solvent as well as the composition of mixed solvent. The change trend of discharge performance as a function of content of each solvent component is studied. Capacity value increases as the 1,3-dioxolane (DOX) content decreases. Average discharge voltage shows larger value when the 1,2-dimethoxy ethane (DME) content is small. Finally, we have obtained the optimal solvent composition by using a statistical method

  13. Characterization of lecithin isolated from anchovy (Engraulis japonica) residues deoiled by supercritical carbon dioxide and organic solvent extraction.

    Science.gov (United States)

    Lee, Seung-Mi; Asaduzzaman, A K M; Chun, Byung-Soo

    2012-07-01

    Lecithin was isolated and characterized from anchovy (Engraulis japonica) deoiled residues using supercritical carbon dioxide (SC-CO(2)) at a semibatch flow extraction process and an organic solvent (hexane) extraction. SC-CO(2) extraction was carried out to extract oil from anchovy at different temperatures (35 to 45 °C) and pressures (15 to 25 MPa). Extraction yield of oil was influenced by physical properties of SC-CO(2) with temperature and pressure changes. The major phospholipids of anchovy lecithin were quantitatively analyzed by high-performance liquid chromatography. Phosphatidylcholine (PC) (68%± 1.00%) and phosphatidylethanolamine (PE) (29%± 0.50%) were the main phospholipids. Thin layer chromatography was performed to purify the individual phospholipids. The fatty acid compositions of lecithin, PC, and PE were analyzed by gas chromatography. A significant amount of eicosapentaenoic acid and docosahexaenoic acid were present in both phospholipids of PC and PE. Emulsions of lecithin in water were prepared through the use of a homogenizer. Oxidative stability of anchovy lecithin was high in spite of its high concentration of long-chain polyunsaturated fatty acids. Lecithin can be totally metabolized by humans, so is well tolerated by humans and nontoxic when ingested. Lecithin from anchovy contain higher amounts of ω-3 fatty acids especially EPA and DHA, it may have positive outcome to use in food and pharmaceutical industries. © 2012 Institute of Food Technologists®

  14. Surpassing 10% Efficiency Benchmark for Nonfullerene Organic Solar Cells by Scalable Coating in Air from Single Nonhalogenated Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Long [Department of Physics, Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh NC 27695 USA; Xiong, Yuan [Department of Physics, Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh NC 27695 USA; Zhang, Qianqian [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill NC 27599 USA; Li, Sunsun [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; Wang, Cheng [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley CA 94720 USA; Jiang, Zhang [Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 USA; Hou, Jianhui [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; You, Wei [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill NC 27599 USA; Ade, Harald [Department of Physics, Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh NC 27695 USA

    2018-01-10

    The commercialization of nonfullerene organic solar cells (OSCs) relies critically on the response under typical operating conditions (for instance, temperature, humidity) and the ability of scale-up. Despite the rapid increase in power conversion efficiency (PCE) of spin-coated devices fabricated in a protective atmosphere, the device efficiencies of printed nonfullerene OSC devices by blade-coating are still lower than 6%. This slow progress significantly limits the practical printing of high-performance nonfullerene OSCs. Here, a new and stable nonfullerene combination was introduced by pairing a commercially available nonfluorinated acceptor IT-M with the polymeric donor FTAZ. Over 12%-efficiency can be achieved in spincoated FTAZ:IT-M devices using a single halogen-free solvent. More importantly, chlorinefree, in air blade-coating of FTAZ:IT-M is able to yield a PCE of nearly 11%, despite a humidity of ~50%. X-ray scattering results reveal that large π-π coherence lengths, high degree of faceon orientation with respect to the substrate, and small domain spacings of ~20 nm are closely correlated with such high device performance. Our material system and approach yields the highest reported performance for nonfullerene OSC devices by a coating technique approximating scalable fabrication methods and holds great promise for the development of low-cost, low-toxicity, and high-efficiency OSCs by high-throughput production.

  15. Transesterification of waste cooking oil by an organic solvent-tolerant alkaline lipase from Streptomyces sp. CS273.

    Science.gov (United States)

    Mander, Poonam; Yoo, Hah-Young; Kim, Seung Wook; Choi, Yun Hee; Cho, Seung Sik; Yoo, Jin Cheol

    2014-02-01

    The aim of this present study was to produce a microbial enzyme that can potentially be utilized for the enzymatic transesterification of waste cooking oil. To that end, an extracellular lipase was isolated and purified from the culture broth of Streptomyces sp. CS273. The molecular mass of purified lipase was estimated to be 36.55 kDa by SDS PAGE. The optimum lipolytic activity was obtained at alkaline pH 8.0 to 8.5 and temperature 40 °C, while the enzyme was stable in the pH range 7.0 ∼ 9.0 and at temperature ≤40 °C. The lipase showed highest hydrolytic activity towards p-nitrophenyl myristate (C14). The lipase activity was enhanced by several salts and detergents including NaCl, MnSo₄, and deoxy cholic acid, while phenylmethylsulfonyl fluoride at concentration 10 mM inhibited the activity. The lipase showed tolerance towards different organic solvents including ethanol and methanol which are commonly used in transesterification reactions to displace alcohol from triglycerides (ester) contained in renewable resources to yield fatty acid alkyl esters known as biodiesel. Applicability of the lipase in transesterification of waste cooking oil was confirmed by gas chromatography mass spectrometry analysis.

  16. Improved interfacial adhesion in carbon fiber/polyether sulfone composites through an organic solvent-free polyamic acid sizing

    International Nuclear Information System (INIS)

    Yuan, Haojie; Zhang, Shouchun; Lu, Chunxiang; He, Shuqing; An, Feng

    2013-01-01

    An organic solvent-free polyamic acid (PAA) nanoemulsion was obtained by direct ionization of the solid PAA in deionized water, with the average particle size of 261 nm and Zeta potential of −55.1 mV, and used as a carbon fiber sizing to improve the interfacial adhesion between the carbon fiber and polyether sulfone (PES). The surface characteristics of PAA coated carbon fibers were investigated using Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and dynamic contact angle measurement. The results demonstrated that a continuous and uniform PAA sizing layer was formed on the surface of carbon fibers, and the surface energy of carbon fibers increased from 42.91 to 54.55 mN/m after sizing treatment. The single fiber pull-out testing was also performed, which showed the increased interfacial shear strength (IFSS) of carbon fiber/PES composites from 33.6 to 49.7 MPa by 47.9%. The major reasons for the improved interfacial adhesion were the increased van der Waals forces between the PES matrix and sizing layer as well as the chemical bonding between the sizing layer and carbon fiber surface. Furthermore, the PAA sizing also presented a positive effect on the interfacial adhesion of carbon fiber/PES composites under hydrothermal condition.

  17. Improved interfacial adhesion in carbon fiber/polyether sulfone composites through an organic solvent-free polyamic acid sizing

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Haojie [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Shouchun, E-mail: zschun@sxicc.ac.cn [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Lu, Chunxiang, E-mail: chunxl@sxicc.ac.cn [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); He, Shuqing [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); An, Feng [National Engineering Laboratory for carbon fiber technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)

    2013-08-15

    An organic solvent-free polyamic acid (PAA) nanoemulsion was obtained by direct ionization of the solid PAA in deionized water, with the average particle size of 261 nm and Zeta potential of −55.1 mV, and used as a carbon fiber sizing to improve the interfacial adhesion between the carbon fiber and polyether sulfone (PES). The surface characteristics of PAA coated carbon fibers were investigated using Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and dynamic contact angle measurement. The results demonstrated that a continuous and uniform PAA sizing layer was formed on the surface of carbon fibers, and the surface energy of carbon fibers increased from 42.91 to 54.55 mN/m after sizing treatment. The single fiber pull-out testing was also performed, which showed the increased interfacial shear strength (IFSS) of carbon fiber/PES composites from 33.6 to 49.7 MPa by 47.9%. The major reasons for the improved interfacial adhesion were the increased van der Waals forces between the PES matrix and sizing layer as well as the chemical bonding between the sizing layer and carbon fiber surface. Furthermore, the PAA sizing also presented a positive effect on the interfacial adhesion of carbon fiber/PES composites under hydrothermal condition.

  18. Novel ordered structures in the mixture of water/organic solvent/salts investigated by neutron scattering

    International Nuclear Information System (INIS)

    Sadakane, Koichiro

    2013-01-01

    The effect of an antagonistic salt on the phase behavior and nanoscale structure of a mixture of water/organic solvent was investigated by visual inspection, optical microscope, and small-angle neutron scattering (SANS). The addition of the antagonistic salt, namely sodium tetraphenylborate (NaBPh 4 ), induces the shrinking of the two-phase region in contrast to the case in which a normal (hydrophilic) salt is added. Below the phase separation point, the SANS profiles cannot be described by the Ornstein-Zernike function owing to the existence of a long-range periodic structure. With increasing salt concentration, the critical exponents change from the values of 3D-Ising and approach those of 2D-Ising. Furthermore, an ordered phase with multilamellar (onion) structures was confirmed in an off-critical mixture of D 2 O and 3-methylpyridine containing 85 mM of a NaBPh 4 although no surfactants or polymers are contained. (author)

  19. Mechanical properties of wood from Pinus sylvestris L. treated with Light Organic Solvent Preservative and with waterborne Copper Azole

    Energy Technology Data Exchange (ETDEWEB)

    Villasante, A.; Laina, R.; Rojas, J. A. M.; Rojas, I. M.; Vignote, S.

    2013-07-01

    Aim of study: To determine the effect on wood from Pinus sylvestris of treatment with preservatives on mechanical properties and to establish the relation between the penetration and compression strenght. Area of study: Spain. Material and methods: 40 samples of defect-free wood from Pinus sylvestris L. were treated with Light Organic Solvent Preservative (Vacsol Azure WR 2601) and 50 with waterborne Copper Azole (Tanalith E 3492). 40 control samples were not treated (water or preservative). Mechanical resistance to static bending, modulus of elasticity and compression strength parallel to the grain were compared with untreated wood. Regression analysis between the penetration and compression strength parallel was done with the samples treated with waterborne preservative. Main results: The results indicate that the treated wood (with either product) presents a statistically significant increase in mechanical resistance in all three mechanical characteristics. The results obtained differ from earlier studies carried out by other authors. There was no correlation between parallel compression strength and the degree of impregnation of the wood with waterborne Copper Azole. The most probable explanation for these results concerns changes in pressure during treatment. The use of untreated control samples instead of samples treated only with water is more likely to produce significant results in the mechanical resistance studies. Research highlights: Treated wood presents a statistically significant increase in MOE, modulus of rupture to static bending and parallel compression strength. There was no correlation between parallel compression strength and the degree of impregnation with waterborne preservative. (Author)

  20. Combinatorial library based engineering of Candida antarctica lipase A for enantioselective transacylation of sec-alcohols in organic solvent.

    Science.gov (United States)

    Wikmark, Ylva; Svedendahl Humble, Maria; Bäckvall, Jan-E

    2015-03-27

    A method for determining lipase enantioselectivity in the transacylation of sec-alcohols in organic solvent was developed. The method was applied to a model library of Candida antarctica lipase A (CalA) variants for improved enantioselectivity (E values) in the kinetic resolution of 1-phenylethanol in isooctane. A focused combinatorial gene library simultaneously targeting seven positions in the enzyme active site was designed. Enzyme variants were immobilized on nickel-coated 96-well microtiter plates through a histidine tag (His6-tag), screened for transacylation of 1-phenylethanol in isooctane, and analyzed by GC. The highest enantioselectivity was shown by the double mutant Y93L/L367I. This enzyme variant gave an E value of 100 (R), which is a dramatic improvement on the wild-type CalA (E=3). This variant also showed high to excellent enantioselectivity for other secondary alcohols tested. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.