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Sample records for organic solvent buffer

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

    PubMed

    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%.

  2. Organic solvent topical report

    SciTech Connect

    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.

  3. Organic solvent topical report

    SciTech Connect

    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.

  4. Solvent effects on chemical processes. 8. Demethylation kinetics of aspartame in binary aqueous-organic solvents.

    PubMed

    Skwierczynski, R D; Connors, K A

    1994-12-01

    The kinetics of demethylation of aspartame were studied in binary aqueous-organic solvent mixtures at 25 degrees C under two solution conditions, namely 1.0 M HCl (pH 0.28 in water) and carbonate buffer (pH 10.1 in water). Under these conditions solvent effects on the acid dissociation constants of aspartame do not complicate the interpretation of the kinetics. The organic cosolvents were acetone, acetonitrile, dimethyl sulfoxide, dioxane, tetrahydrofuran, and methanol. The observed kinetic solvent effects were modest in magnitude, not exceeding a factor of 3 in rate constant, relative to the fully aqueous solution. The rate changes included both increases and decreases, and in some solvent mixtures extrema were observed. It is concluded that at least two contributory factors, identified as an electrostatic (dielectric constant) effect and a solvation effect, must be operating to produce the observed kinetic solvent effects.

  5. Ionic equilibria in neutral amphiprotic solvents of low dielectric constant: Buffer solutions.

    PubMed

    Bosch, E; Rosés, M

    1989-06-01

    The ionic equilibria in neutral amphiprotic solvents (isopropyl and tert-butyl alcohols) have been established, and equations to calculate pH values in solutions of acids, bases, salts or their mixtures, developed. The effect, on the dissociation equilibria, of the presence of small quantities of water or other solvents in the bulk solvent used has been taken into account in the proposed equations. On the basis of these equations some buffer solutions have been studied and recommended for electrode standardization. The results, tested by experimental work, show the importance of the incompleteness of dissociation of salts in these solvents, which decreases the pH of acid buffers and increases the buffer capacity.

  6. Organic Solvent Effects in Biomass Conversion Reactions.

    PubMed

    Shuai, Li; Luterbacher, Jeremy

    2016-01-01

    Transforming lignocellulosic biomass into fuels and chemicals has been intensely studied in recent years. A large amount of work has been dedicated to finding suitable solvent systems, which can improve the transformation of biomass into value-added chemicals. These efforts have been undertaken based on numerous research results that have shown that organic solvents can improve both conversion and selectivity of biomass to platform molecules. We present an overview of these organic solvent effects, which are harnessed in biomass conversion processes, including conversion of biomass to sugars, conversion of sugars to furanic compounds, and production of lignin monomers. A special emphasis is placed on comparing the solvent effects on conversion and product selectivity in water with those in organic solvents while discussing the origins of the differences that arise. We have categorized results as benefiting from two major types of effects: solvent effects on solubility of biomass components including cellulose and lignin and solvent effects on chemical thermodynamics including those affecting reactants, intermediates, products, and/or catalysts. Finally, the challenges of using organic solvents in industrial processes are discussed from the perspective of solvent cost, solvent stability, and solvent safety. We suggest that a holistic view of solvent effects, the mechanistic elucidation of these effects, and the careful consideration of the challenges associated with solvent use could assist researchers in choosing and designing improved solvent systems for targeted biomass conversion processes.

  7. Organic Solvent Effects in Biomass Conversion Reactions.

    PubMed

    Shuai, Li; Luterbacher, Jeremy

    2016-01-01

    Transforming lignocellulosic biomass into fuels and chemicals has been intensely studied in recent years. A large amount of work has been dedicated to finding suitable solvent systems, which can improve the transformation of biomass into value-added chemicals. These efforts have been undertaken based on numerous research results that have shown that organic solvents can improve both conversion and selectivity of biomass to platform molecules. We present an overview of these organic solvent effects, which are harnessed in biomass conversion processes, including conversion of biomass to sugars, conversion of sugars to furanic compounds, and production of lignin monomers. A special emphasis is placed on comparing the solvent effects on conversion and product selectivity in water with those in organic solvents while discussing the origins of the differences that arise. We have categorized results as benefiting from two major types of effects: solvent effects on solubility of biomass components including cellulose and lignin and solvent effects on chemical thermodynamics including those affecting reactants, intermediates, products, and/or catalysts. Finally, the challenges of using organic solvents in industrial processes are discussed from the perspective of solvent cost, solvent stability, and solvent safety. We suggest that a holistic view of solvent effects, the mechanistic elucidation of these effects, and the careful consideration of the challenges associated with solvent use could assist researchers in choosing and designing improved solvent systems for targeted biomass conversion processes. PMID:26676907

  8. Method of stripping metals from organic solvents

    DOEpatents

    Todd, Terry A.; Law, Jack D.; Herbst, R. Scott; Romanovskiy, Valeriy N.; Smirnov, Igor V.; Babain, Vasily A.; Esimantovski, Vyatcheslav M.

    2009-02-24

    A new method to strip metals from organic solvents in a manner that allows for the recycle of the stripping agent. The method utilizes carbonate solutions of organic amines with complexants, in low concentrations, to strip metals from organic solvents. The method allows for the distillation and reuse of organic amines. The concentrated metal/complexant fraction from distillation is more amenable to immobilization than solutions resulting from current practice.

  9. Organic Solvent Tolerant Lipases and Applications

    PubMed Central

    Kanwar, Shamsher S.

    2014-01-01

    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. PMID:24672342

  10. Hematin crystallization from aqueous and organic solvents

    NASA Astrophysics Data System (ADS)

    Ketchum, Megan A.; Olafson, Katy N.; Petrova, Elena V.; Rimer, Jeffrey D.; Vekilov, Peter G.

    2013-09-01

    Hematin crystallization is the main mechanism of detoxification of heme that is released in malaria-infected erythrocytes as a byproduct of the hemoglobin catabolism by the parasite. A controversy exists over whether hematin crystals grow from the aqueous medium of the parasite's digestive vacuole or in the lipid bodies present in the vacuole. To this end, we compare the basic thermodynamic and structural features of hematin crystallization in an aqueous buffer at pH 4.8, as in the digestive vacuole, and in water-saturated octanol that mimics the environment of the lipid nanospheres. We show that in aqueous solutions, hematin aggregation into mesoscopic disordered clusters is insignificant. We determine the solubility of the β-hematin crystals in the pH range 4.8-7.6. We image by atomic force microscopy crystals grown at pH 4.8 and show that their macroscopic and mesoscopic morphology features are incompatible with those reported for biological hemozoin. In contrast, crystals grown in the presence of octanol are very similar to those extracted from parasites. We determine the hematin solubility in water-saturated octanol at three temperatures. These solubilities are four orders of magnitude higher than that at pH 4.8, providing for faster crystallization from organic than from aqueous solvents. These observations further suggest that the lipid bodies play a role in mediating biological hemozoin crystal growth to ensure faster heme detoxification.

  11. Organic solvent regeneration of granular activated carbon

    NASA Astrophysics Data System (ADS)

    Cross, W. H.; Suidan, M. T.; Roller, M. A.; Kim, B. R.; Gould, J. P.

    1982-09-01

    The use of activated carbon for the treatment of industrial waste-streams was shown to be an effective treatment. The high costs associated with the replacement or thermal regeneration of the carbon have prohibited the economic feasibility of this process. The in situ solvent regeneration of activated carbon by means of organic solvent extraction was suggested as an economically alternative to thermal regeneration. The important aspects of the solvent regeneration process include: the physical and chemical characteristics of the adsorbent, the pore size distribution and energy of adsorption associated with the activated carbon; the degree of solubility of the adsorbate in the organic solvent; the miscibility of the organic solvent in water; and the temperature at which the generation is performed.

  12. SOLVENT-FREE ORGANIC SYNTHESES USING MICROWAVES

    EPA Science Inventory

    The latest results on microwave-expedited solvent-free approach as applied to the assembly of organic molecules will be presented. The salient features of this expeditious methodology such as solvent conservation and ease of manipulation etc. will be described in the context of r...

  13. Zebrafish as a Model for Systems Medicine R&D: Rethinking the Metabolic Effects of Carrier Solvents and Culture Buffers Determined by (1)H NMR Metabolomics.

    PubMed

    Akhtar, Muhammad T; Mushtaq, Mian Y; Verpoorte, Robert; Richardson, Michael K; Choi, Young H

    2016-01-01

    Zebrafish is a frequently employed model organism in systems medicine and biomarker discovery. A crosscutting fundamental question, and one that has been overlooked in the field, is the "system-wide" (omics) effects induced in zebrafish by metabolic solvents and culture buffers. Indeed, any bioactivity or toxicity test requires that the target compounds are dissolved in an appropriate nonpolar solvent or aqueous media. It is important to know whether the solvent or the buffer itself has an effect on the zebrafish model organism. We evaluated the effects of two organic carrier solvents used in research with zebrafish, as well as in drug screening: dimethyl sulfoxide (DMSO) and ethanol, and two commonly used aqueous buffers (egg water and Hank's balanced salt solution). The effects of three concentrations (0.01, 0.1, and 1%) of DMSO and ethanol were tested in the 5-day-old zebrafish embryo using proton nuclear magnetic resonance ((1)H NMR) based metabolomics. DMSO (1% and 0.1%, but not 0.01%) exposure significantly decreased the levels of adenosine triphosphate (ATP), betaine, alanine, histidine, lactate, acetate, and creatine (p < 0.05). By contrast, ethanol exposure did not alter the embryos' metabolome at any concentration tested. The two different aqueous media noted above impacted the zebrafish embryo metabolome as evidenced by changes in valine, alanine, lactate, acetate, betaine, glycine, glutamate, adenosine triphosphate, and histidine. These results show that DMSO has greater effects on the embryo metabolome than ethanol, and thus is used with caution as a carrier solvent in zebrafish biomarker research and oral medicine. Moreover, the DMSO concentration should not be higher than 0.01%. Careful attention is also warranted for the use of the buffers egg water and Hank's balanced salt solution in zebrafish. In conclusion, as zebrafish is widely used as a model organism in life sciences, metabolome changes induced by solvents and culture buffers warrant further

  14. Solvent-free fluidic organic dye lasers.

    PubMed

    Choi, Eun Young; Mager, Loic; Cham, Tran Thi; Dorkenoo, Kokou D; Fort, Alain; Wu, Jeong Weon; Barsella, Alberto; Ribierre, Jean-Charles

    2013-05-01

    We report on the demonstration of liquid organic dye lasers based on 9-(2-ethylhexyl)carbazole (EHCz), so-called liquid carbazole, doped with green- and red-emitting laser dyes. Both waveguide and Fabry-Perot type microcavity fluidic organic dye lasers were prepared by capillary action under solvent-free conditions. Cascade Förster-type energy transfer processes from liquid carbazole to laser dyes were employed to achieve color-variable amplified spontaneous emission and lasing. Overall, this study provides the first step towards the development of solvent-free fluidic organic semiconducting lasers and demonstrates a new kind of optoelectronic applications for liquid organic semiconductors.

  15. Effect of salts, solvents and buffer on miRNA detection using DNA silver nanocluster (DNA/AgNCs) probes

    NASA Astrophysics Data System (ADS)

    Shah, Pratik; Cho, Seok Keun; Waaben Thulstrup, Peter; Bhang, Yong-Joo; Ahn, Jong Cheol; Choi, Suk Won; Rørvig-Lund, Andreas; Yang, Seong Wook

    2014-01-01

    MicroRNAs (miRNAs) are small regulatory RNAs (size ˜21 nt to ˜25 nt) which regulate a variety of important cellular events in plants, animals and single cell eukaryotes. Especially because of their use in diagnostics of human diseases, efforts have been directed towards the invention of a rapid, simple and sequence selective detection method for miRNAs. Recently, we reported an innovative method for the determination of miRNA levels using the red fluorescent properties of DNA/silver nanoclusters (DNA/AgNCs). Our method is based on monitoring the emission drop of a DNA/AgNCs probe in the presence of its specific target miRNA. Accordingly, the accuracy and efficiency of the method relies on the sensitivity of hybridization between the probe and target. To gain specific and robust hybridization between probe and target, we investigated a range of diverse salts, organic solvents, and buffer to optimize target sensing conditions. Under the newly adjusted conditions, the target sensitivity and the formation of emissive DNA/AgNCs probes were significantly improved. Also, fortification of the Tris-acetate buffer with inorganic salts or organic solvents improved the sensitivity of the DNA/AgNC probes. On the basis of these optimizations, the versatility of the DNA/AgNCs-based miRNA detection method can be expanded.

  16. Polar organic solvents accelerate the rate of DNA strand replacement reaction.

    PubMed

    Zhang, Tianchi; Shang, Chunli; Duan, Ruixue; Hakeem, Abdul; Zhang, Zhenyu; Lou, Xiaoding; Xia, Fan

    2015-03-21

    Herein, we report a novel strategy to accelerate the rate of DNA strand replacement reaction (DSRR) by polar organic solvents. DSRR plays a vital role in DNA nanotechnology but prolonged reaction time limits its further advancement. That is why it is extremely important to speed up the rate of DSRR. In this work, we introduce different polar organic solvents in both simple and complicated DSRR systems and observe that the rate constant is much more than in aqueous buffer. The rate acceleration of DSRR by polar organic solvents is very obvious and we believe that this strategy will extend the application of DNA nanotechnology in future.

  17. Co-solvent enhanced zinc oxysulfide buffer layers in Kesterite copper zinc tin selenide solar cells.

    PubMed

    Steirer, K Xerxes; Garris, Rebekah L; Li, Jian V; Dzara, Michael J; Ndione, Paul F; Ramanathan, Kannan; Repins, Ingrid; Teeter, Glenn; Perkins, Craig L

    2015-06-21

    A co-solvent, dimethylsulfoxide (DMSO), is added to the aqueous chemical "bath" deposition (CBD) process used to grow ZnOS buffer layers for thin film Cu2ZnSnSe4 (CZTSe) solar cells. Device performance improves markedly as fill factors increase from 0.17 to 0.51 upon the co-solvent addition. X-ray photoelectron spectroscopy (XPS) analyses are presented for quasi-in situ CZTSe/CBD-ZnOS interfaces prepared under an inert atmosphere and yield valence band offsets equal to -1.0 eV for both ZnOS preparations. When combined with optical band gap data, conduction band offsets exceed 1 eV for the water and the water/DMSO solutions. XPS measurements show increased downward band bending in the CZTSe absorber layer when the ZnOS buffer layer is deposited from water only. Admittance spectroscopy data shows that the ZnOS deposited from water increases the built-in potential (Vbi) yet these solar cells perform poorly compared to those made with DMSO added. The band energy offsets imply an alternate form of transport through this junction. Possible mechanisms are discussed, which circumvent the otherwise large conduction band spike between CZTSe and ZnOS, and improve functionality with the low-band gap absorber, CZTSe (Eg = 0.96 eV). PMID:26000570

  18. Co-solvent enhanced zinc oxysulfide buffer layers in Kesterite copper zinc tin selenide solar cells.

    PubMed

    Steirer, K Xerxes; Garris, Rebekah L; Li, Jian V; Dzara, Michael J; Ndione, Paul F; Ramanathan, Kannan; Repins, Ingrid; Teeter, Glenn; Perkins, Craig L

    2015-06-21

    A co-solvent, dimethylsulfoxide (DMSO), is added to the aqueous chemical "bath" deposition (CBD) process used to grow ZnOS buffer layers for thin film Cu2ZnSnSe4 (CZTSe) solar cells. Device performance improves markedly as fill factors increase from 0.17 to 0.51 upon the co-solvent addition. X-ray photoelectron spectroscopy (XPS) analyses are presented for quasi-in situ CZTSe/CBD-ZnOS interfaces prepared under an inert atmosphere and yield valence band offsets equal to -1.0 eV for both ZnOS preparations. When combined with optical band gap data, conduction band offsets exceed 1 eV for the water and the water/DMSO solutions. XPS measurements show increased downward band bending in the CZTSe absorber layer when the ZnOS buffer layer is deposited from water only. Admittance spectroscopy data shows that the ZnOS deposited from water increases the built-in potential (Vbi) yet these solar cells perform poorly compared to those made with DMSO added. The band energy offsets imply an alternate form of transport through this junction. Possible mechanisms are discussed, which circumvent the otherwise large conduction band spike between CZTSe and ZnOS, and improve functionality with the low-band gap absorber, CZTSe (Eg = 0.96 eV).

  19. 40 CFR 52.1145 - Regulation on organic solvent use.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Regulation on organic solvent use. 52... on organic solvent use. (a) Definitions: (1) Organic solvents include diluents and thinners and are defined as organic materials which are liquids at standard conditions and which are used as...

  20. 40 CFR 52.1145 - Regulation on organic solvent use.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Regulation on organic solvent use. 52... on organic solvent use. (a) Definitions: (1) Organic solvents include diluents and thinners and are defined as organic materials which are liquids at standard conditions and which are used as...

  1. 40 CFR 52.1145 - Regulation on organic solvent use.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Regulation on organic solvent use. 52... on organic solvent use. (a) Definitions: (1) Organic solvents include diluents and thinners and are defined as organic materials which are liquids at standard conditions and which are used as...

  2. Organic Solvent Tropical Report [SEC 1 and 2

    SciTech Connect

    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.

  3. Indentation of polydimethylsiloxane submerged in organic solvents

    NASA Astrophysics Data System (ADS)

    Hu, Yuhang; Chen, Xin; Whitesides, George; Vlassak, Joost; Suo, Zhigang

    2011-03-01

    This study uses a method based on indentation to characterize a polydimethylsiloxane (PDMS) elastomer submerged in an organic solvent (decane, heptane, pentane, or cyclohexane). An indenter is pressed into a disk of a swollen elastomer to a fixed depth, and the force on the indenter is recorded as a function of time. By examining how the relaxation time scales with the radius of contact, one can differentiate the poroelastic behavior from the viscoelastic behavior. By matching the relaxation curve measured experimentally to that derived from the theory of poroelasticity, one can identify elastic constants and permeability. The measured elastic constants are interpreted within the Flory-Huggins theory. The measured permeabilities indicate that the solvents migrate in PDMS by diffusion, rather than by convection. This work confirms that indentation is a reliable and convenient method to characterize swollen elastomers.

  4. Fast molecular beacon hybridization in organic solvents with improved target specificity.

    PubMed

    Dave, Neeshma; Liu, Juewen

    2010-12-01

    DNA hybridization is of tremendous importance in biology, bionanotechnology, and biophysics. Molecular beacons are engineered DNA hairpins with a fluorophore and a quencher labeled on each of the two ends. A target DNA can open the hairpin to give an increased fluorescence signal. To date, the majority of molecular beacon detections have been performed only in aqueous buffers. We describe herein DNA detection in nine different organic solvents, methanol, ethanol, isopropanol, acetonitrile, formamide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethylene glycol, and glycerol, varying each up to 75% (v/v). In comparison with detection in water, the detection in organic solvents showed several important features. First, the molecular beacon hybridizes to its target DNA in the presence of all nine solvents up to a certain percentage. Second, the rate of this hybridization was significantly faster in most organic solvents compared with water. For example, in 56% ethanol, the beacon showed a 70-fold rate enhancement. Third, the ability of the molecular beacon to discriminate single-base mismatch is still maintained. Lastly, the DNA melting temperature in the organic solvents showed a solvent concentration-dependent decrease. This study suggests that molecular beacons can be used for applications where organic solvents must be involved or organic solvents can be intentionally added to improve the molecular beacon performance.

  5. Swelling of lignites in organic solvents

    SciTech Connect

    R.G. Makitra; D.V. Bryk

    2008-10-15

    Data on the swelling of Turkish lignites can be summarized using linear multiparameter equations that take into account various properties of solvents. Factors responsible for the amounts of absorbed solvents are the basicity and cohesion energy density of the solvents.

  6. NOVEL POLYMERIC MEMBRANE FOR DEHYDRATION OF ORGANIC SOLVENTS

    EPA Science Inventory

    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...

  7. Solid-state enzyme deactivation in air and in organic solvents

    SciTech Connect

    Toscano, G.; Pirozzi, D.; Maremonti, M.; Greco, G. Jr. . Dipartimento di Ingegneria Chimica)

    1994-09-05

    Thermal deactivation of solid-state acid phosphatase is analyzed, both in the presence and in the absence of organic solvents. The thermal deactivation profile departs from first order kinetics and shows an unusual, temperature-dependent, asymptotic value of residual activity. The process is described by a phenomenological equation, whose theoretical implications are also discussed. The total amount of buffer salts in the enzyme powder dramatically affects enzyme stability in the range 70 to 105 C. The higher salt/protein ratio increases the rate of thermal deactivation. The deactivation rate is virtually unaffected by the presence of organic solvents, independent of their hydrophilicity.

  8. 40 CFR Table 3 to Subpart Nnnn of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in... formulation data. Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic...

  9. 40 CFR Table 3 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false 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. Average organic HAP mass fraction Typical organic HAP, percent by mass...

  10. 40 CFR Table 5 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in... formulation data. Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic...

  11. 40 CFR Table 5 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in... formulation data. Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in... formulation data. Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic...

  13. 40 CFR Table 3 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false 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. Average organic HAP mass fraction Typical organic HAP, percent by mass...

  14. 40 CFR Table 3 to Subpart Nnnn of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in... formulation data. Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic...

  15. Interaction of organic solvents with the green alga Chlorella pyrenoidosa

    SciTech Connect

    Stratton, G.W.; Smith, T.M. )

    1988-06-01

    Solvents are often a component of bioassay systems when water-insoluble toxicants are being tested. These solvents must also be considered as xenobiotics and therefore, as potential toxicants in the bioassay. However, the effects of solvents on the organisms being tested and their possible interaction with the test compound are often overlooked by researchers. The purpose of the present study was to compare the inhibitory effects of six solvents commonly used in pesticide bioassays towards growth of the common green alga Chlorella pyrenoidosa, and to examine the occurrence of solvent-pesticide interactions with this organism.

  16. A newly isolated organic solvent tolerant Staphylococcus saprophyticus M36 produced organic solvent-stable lipase.

    PubMed

    Fang, Yaowei; Lu, Zhaoxin; Lv, Fengxia; Bie, Xiaomei; Liu, Shu; Ding, Zhongyang; Xu, Weifeng

    2006-12-01

    Thirty-eight high lipase activity strains were isolated from soil, seawater, and Brassica napus. Among them, a novel organic solvent tolerant bacterium (strain M36) was isolated from the seawater in Jiangsu, China. Isolate M36 was able to grow at high concentration of benzene or toluene up to 40% (vol/vol), and later identified as Staphylococcus saprophyticus by biochemical test and 16s ribosomal DNA sequence. No work on Staphylococcus producing lipase with organic solvent tolerance has been reported so far. The lipase of strain M36 whose activity in liquid medium was 42 U mL(-1) at 24-h incubation time was stable in the presence of 25% (vol/vol) p-xylene, benzene, toluene, and hexane.

  17. COSOLVENCY OF PARTIALLY MISCIBLE ORGANIC SOLVENTS ON THE SOLUBILITY OF HYDROPHOBIC ORGANIC CHEMICALS

    EPA Science Inventory

    The cosolvency of completely miscible organic solvents (CMOSs) and partially miscible organic solvents (PMOSs) on the solubility of hydrophobic organic chemicals (HOCs) was examined, with an emphasis on PMOSs. Measured solubilities were compared with predictions from the log- lin...

  18. 40 CFR Table 6 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false 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...

  19. 40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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,...

  20. 40 CFR Table 6 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false 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. 40 CFR Table 6 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 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...

  2. 40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2010 CFR

    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,...

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

    Code of Federal Regulations, 2010 CFR

    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...

  4. 40 CFR Table 3 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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...

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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...

  6. Dispersion and separation of nanostructured carbon in organic solvents

    NASA Technical Reports Server (NTRS)

    Landi, Brian J. (Inventor); Raffaelle, Ryne P. (Inventor); Ruf, Herbert J. (Inventor); Evans, Christopher M. (Inventor)

    2011-01-01

    The present invention relates to dispersions of nanostructured carbon in organic solvents containing alkyl amide compounds and/or diamide compounds. The invention also relates to methods of dispersing nanostructured carbon in organic solvents and methods of mobilizing nanostructured carbon. Also disclosed are methods of determining the purity of nanostructured carbon.

  7. Mechanism of paint removing by organic solvents

    SciTech Connect

    Del Nero, V.; Siat, C.; Marti, M.J.; Aubry, J.M.; Lallier, J.P.; Dupuy, N.; Huvenne, J.P.

    1996-01-01

    The mechanism of paint removing has been studied by comparing the stripping efficiency of a given solvent with its ability to swell the film. The most effective solvents have a Hildebrand{close_quote}s parameter, {delta}{sub H}, ranging from 10.5 to 12 and a Dimroth parameter, ET{sub (30)}, ranging from 0.25 to 0.4. The synergy observed with the mixtures DMSO/non polar solvent is explained by a dissociation of the DMSO clusters into individual molecules which diffuse more easily. {copyright} {ital 1996 American Institute of Physics.}

  8. Dispersion of carbon nanotubes using organic solvents.

    PubMed

    Dumonteil, S; Demortier, A; Detriche, S; Raes, C; Fonseca, A; Rühle, M; Nagy, J B

    2006-05-01

    Phenyl ethyl alcohol was used for fast and stable dispersion of carbon nanotubes. This solvent, more effective than ethanol and toluene, allows easy dispersion of carbon nanotubes for TEM characterization. For TEM grids prepared at high dilution, it is possible to observe each tube separately. Applying that solvent, it was possible to measure the length, the diameter and the solubility of different carbon nanotubes samples.

  9. 40 CFR Table 3 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for... of Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass... manufacturer's formulation data Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical...

  10. 40 CFR Table 3 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for... of Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass... manufacturer's formulation data Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for... of Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass... manufacturer's formulation data Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for... MMMM of Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass... organic HAP mass fraction must be used for that solvent blend. Otherwise, use the organic HAP...

  13. 40 CFR Table 3 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for... MMMM of Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass... organic HAP mass fraction must be used for that solvent blend. Otherwise, use the organic HAP...

  14. 40 CFR Table 3 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for... MMMM of Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass... organic HAP mass fraction must be used for that solvent blend. Otherwise, use the organic HAP...

  15. The oxidation of chiral alcohols catalyzed by catalase in organic solvents

    SciTech Connect

    Magner, E.; Klibanov, A.M.

    1995-04-20

    The catalytic properties of bovine liver catalase have been investigated in organic solvents. In tetrahydrofuran, dioxane, and acetone (all containing 1% to 3% of water), the enzyme breaks down tert-butyl hydroperoxide several fold faster than in pure water. Furthermore, the rate of catalase-catalyzed production of tert-butanol from tert-butyl hydroperoxide increases more than 400-fold upon transition from aqueous buffer to ethanol as the reaction medium. The mechanistic rationale for this striking effect is that in aqueous buffer the rate-limiting step of the enzymatic process involves the reduction of catalase`s compound 1 by tert-butyl hydroperoxide. In ethanol, an additional step in the reaction scheme becomes available in which ethanol, greatly outcompeting the hydroperoxide, is oxidized by compound 1 regenerating the free enzyme. In solvents, such as acetonitrile or tetrahydrofuran, which themselves are not oxidizable by compound 1, catalase catalyzes the oxidation of numerous primary and secondary alcohols with tert-butyl hydroperoxide to the corresponding aldehydes or ketones. The enzymatic oxidation of some chiral alcohols (2,3-butanediol, citronellol, and menthol) under these conditions occurs enantioselectively. Examination of the enantioselectivity for the oxidation of 2,3-butanediol in a series of organic solvents reveals a considerable solvent dependence.

  16. SOLVENT-FREE ORGANIC SYNTHESES USING SUPPORTED REAGENTS AND MICROWAVES

    EPA Science Inventory

    The latest results on microwave-expedited solvent-free approach as applied to the assembly of organic molecules will be presented. The salient features of this expeditious methodology such as solvent conservation and ease of manipulation etc. will be described in the context of ...

  17. Measurement of oxygen transfer from air into organic solvents

    PubMed Central

    Ramesh, Hemalata; Hobisch, Mathias; Borisov, Sergey; Klimant, Ingo; Krühne, Ulrich; Woodley, John M

    2015-01-01

    Abstract BACKGROUND The use of non‐aqueous organic media is becoming increasingly important in many biotechnological applications in order to achieve process intensification. Such media can be used, for example, to directly extract poorly water‐soluble toxic products from fermentations. Likewise many biological reactions require the supply of oxygen, most normally from air. However, reliable online measurements of oxygen concentration in organic solvents (and hence oxygen transfer rates from air to the solvent) has to date proven impossible due to limitations in the current analytical methods. RESULTS For the first time, online oxygen measurements in non‐aqueous media using a novel optical sensor are demonstrated. 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 applications). Subsequently, the oxygen transfer rates from air into these organic solvents were measured. 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 measurements in organic solvents has also been demonstrated, paving the way for new opportunities in process control. © 2015 The Authors. Journal of Chemical Technology & Biotechnology published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.

  18. Mechanism of transport and distribution of organic solvents in blood

    NASA Technical Reports Server (NTRS)

    Lam, C. W.; Galen, T. J.; Boyd, J. F.; Pierson, D. L.

    1990-01-01

    Little is known about the mechanism of transport and distribution of volatile organic compounds in blood. Studies were conducted on five typical organic solvents to investigate how these compounds are transported and distributed in blood. Groups of four to five rats were exposed for 2 hr to 500 ppm of n-hexane, toluene, chloroform, methyl isobutyl ketone (MIBK), or diethyl ether vapor; 94, 66, 90, 51, or 49%, respectively, of these solvents in the blood were found in the red blood cells (RBCs). Very similar results were obtained in vitro when aqueous solutions of these solvents were added to rat blood. In vitro studies were also conducted on human blood with these solvents; 66, 43, 65, 49, or 46%, respectively, of the added solvent was taken up by the RBCs. These results indicate that RBCs from humans and rats exhibited substantial differences in affinity for the three more hydrophobic solvents studied. When solutions of these solvents were added to human plasma and RBC samples, large fractions (51-96%) of the solvents were recovered from ammonium sulfate-precipitated plasma proteins and hemoglobin. Smaller fractions were recovered from plasma water and red cell water. Less than 10% of each of the added solvents in RBC samples was found in the red cell membrane ghosts. These results indicate that RBCs play an important role in the uptake and transport of these solvents. Proteins, chiefly hemoglobin, are the major carriers of these compounds in blood. It can be inferred from the results of the present study that volatile lipophilic organic solvents are probably taken up by the hydrophobic sites of blood proteins.

  19. Solvent Selection for Recrystallization: An Undergraduate Organic Experiment.

    ERIC Educational Resources Information Center

    Baumann, Jacob B.

    1979-01-01

    This experiment develops the students' ability to carry out a simple recrystallization effectively, and demonstrates how a solvent may be selected or rejected for the recrystallization of a specific organic compound. (Author/BB)

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for... 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...

  1. 40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2010 CFR

    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...

  2. 40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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...

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

    Code of Federal Regulations, 2010 CFR

    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...

  4. 40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for... 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...

  5. 40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for... 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction.... If a solvent blend matches both the name and CAS number for an entry, that entry's organic HAP...

  6. 40 CFR Table 3 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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...

  7. Self-healing Microencapsulation of Biomacromolecules without Organic Solvents**

    PubMed Central

    Reinhold, Samuel E.; Desai, Kashappa-Goud H.; Zhang, Li; Olsen, Karl F.

    2012-01-01

    Microencapsulation of biomacromolecules in PLGA is routinely performed with organic solvent through multiple complex steps deleterious to the biomacromolecule. The new self-healing based PLGA microencapsulation obviates micronization- and organic solvent-induced protein damage, provides very high encapsulation efficiency, exhibit stabilization and slow release of labile tetanus protein antigen, and provides long-term testosterone suppression in rats following a single injection of encapsulated leuprolide. PMID:23011773

  8. Electroenzymatic reactions with oxygen on laccase-modified electrodes in anhydrous (pure) organic solvent.

    PubMed

    Yaropolov, A; Shleev, S; Zaitseva, E; Emnéus, J; Marko-Varga, G; Gorton, L

    2007-05-01

    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 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 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 glassy carbon and graphite electrodes with adsorbed laccase. The influence of the time for drying the laccase solution at the electrode surface on the electroreduction of oxygen was studied. Investigating the electroenzymatic oxidation reaction of catechol and hydroquinone in DMSO reveals the formation of various intermediates of the substrates with different electrochemical activity under oxygenated conditions. The influence of the content of aqueous buffer in the organic solvent on the electrochemical behaviour of hydroquinone/1,4-benzoquinone couple was also studied.

  9. Background Noise Contributes to Organic Solvent Induced Brain Dysfunction

    PubMed Central

    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

  10. Permeation of Tank C-103 sludge simulant by organic solvent

    SciTech Connect

    Gerber, M.A.

    1995-03-01

    The plan for stabilizing underground storage tanks (USTs) calls for draining the supernate from the tanks; however, there is concern that draining the supernate from Tank C-103 will degrade safety in the tank. The sludge in Tank C-103 contains ranges in depth from 1 to 1.5 m and is covered by both an aqueous phase and a separate organic layer. The main concern is that draining the supernate will cause the solvent to permeate the sludge solids and provide a source of fuel for a fire on the surface of the drained sludge. The question of whether the solvent will permeate sludge that is 1 to 1.5 m deep after the tank is dewatered is the purpose of the tests conducted and described in this report. Evaluation of the solvent permeation mechanism required the preparation of solvent, supernate, and sludge simulants based on the known chemistry of Tank C-103. Solvent and aqueous phase supernate simulants are based on the results of fiscal year 1994 sampling of the tank solvent and supernate. Sludge simulant is based on the chemical analyses of tank sludge samples retrieved in 1986. Experiments were conducted with each simulant to evaluate solvent permeation under matric potentials ranging from 0.8 m to 1.8 m of supernate. The amount of solvent recovered for each experiment was recorded as well as the maximum amount of solvent that could be din the sludge based on solvent recovered from resuspended sludge and solvent not recovered. The wt% of water remaining in the sludge was also recorded for each experiment, which was determined by measuring the weight of the sludge after drying it. One observation noted from the test results is that the finer sludge material tended to have a greater amount of solvent loss compared to the coarser sludge material at comparable levels of vacuum. At this time, there is no explanation.

  11. Buffer controlled photoswitching microscopy using standard organic fluorophores

    NASA Astrophysics Data System (ADS)

    Buschmann, Volker; Fore, Samantha; van de Linde, Sebastian; Sauer, Markus; Wolter, Steve; Heilemann, Mike; Koberling, Felix; Erdmann, Rainer

    2011-03-01

    The interest in super-resolution microscopy techniques has dramatically increased in the last years due to the unprecedented insight into cellular structure which has become possible [1]. In all widefield-based techniques, such as Stochastical Optical Reconstruction Microscopy (STORM) or Photo-activation localization microscopy (PALM), the dye-sensor-molecules are switched between a bright and a dark state. Many organic fluorophores exhibit intrinsic dark states with a lifetime that can be tuned by adjusting the level of oxidants and reductants in the buffer, thereby allowing to reversibly switch individual fluorophores between an on- and off-state [2]. This behavior is used in the dSTORM method. We exploited this redox-level adjusted photoswitching behaviour based on addition of millimolar amounts of reducing thiols for high-resolution imaging on a setup based on an inverse microscope coupled with ultrasensitive CCD camera detection. In order to quickly control the quality of the measurement, we used real-time computation of the subdiffraction-resolution image [3]. This greatly increases the applicability of the method, as image analysis times are greatly reduced.

  12. Acute toxicity of organic solvents on Artemia salina

    SciTech Connect

    Barahona-Gomariz, M.V.; Sanz-Barrera, F.; Sanchez-Fortun, S. )

    1994-05-01

    Organic solvents can make their way into the environment as industrial wastes and components of pesticide formulation. In laboratory bioassays, the use of organic formulations. In laboratory bioassays, the use of organic solvents is often unavoidable, since many pesticides and organic pollutants have low water solubility and must be dissolved in organic solvents prior to addition into experimental systems. In the toxicant bioassays, invertebrates with special reference to aquatic arthropod species are of recent interest as test models due to the need for developing nonmammalian test systems. Toxic effects of organic solvents have been tested with a few aquatic species, but information on the comparative toxicity of solvents towards Artemia salina is not available. Artemia salina have, within recent years, gained popularity as test organisms for short-term toxicity testing. Because Artemia salina exhibit rapid development and growth within 48 hr after hatch, their potential as a model organism for toxicology screening has been considered. To do this, synchronous populations of Artemia salina at different development intervals must be available.

  13. Automated process for solvent separation of organic/inorganic substance

    DOEpatents

    Schweighardt, Frank K.

    1986-01-01

    There is described an automated process for the solvent separation of organic/inorganic substances that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In the process, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control apparatus. The mixture in the filter is agitated by ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process.

  14. Automated process for solvent separation of organic/inorganic substance

    DOEpatents

    Schweighardt, F.K.

    1986-07-29

    There is described an automated process for the solvent separation of organic/inorganic substances that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In the process, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control apparatus. The mixture in the filter is agitated by ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process. 4 figs.

  15. Behavioral methods and organic solvents: questions and consequences.

    PubMed Central

    Iregren, A

    1996-01-01

    This paper reviews some illustrative examples of studies of human neurobehavioral effects from experimental as well as long-term occupational organic-solvent exposure. My objective is to present a selection of neurobehavioral solvent studies with the educational aim that we may hopefully learn from the early experiences of others. Some of the methodological problems encountered in these studies are discussed, as well as some reasons for the relative success of the work performed by certain Scandinavian research teams. PMID:9182043

  16. Solvent-dependent cation exchange in metal-organic frameworks.

    PubMed

    Brozek, Carl K; Bellarosa, Luca; Soejima, Tomohiro; Clark, Talia V; López, Núria; Dincă, Mircea

    2014-06-01

    We investigated which factors govern the critical steps of cation exchange in metal-organic frameworks by studying the effect of various solvents on the insertion of Ni(2+) into MOF-5 and Co(2+) into MFU-4l. After plotting the extent of cation insertion versus different solvent parameters, trends emerge that offer insight into the exchange processes for both systems. This approach establishes a method for understanding critical aspects of cation exchange in different MOFs and other materials.

  17. ACTIVE EFFLUX OF ORGANIC SOLVENTS BY PSEUDOMONAS PUTIDA S12 IS INDUCED BY SOLVENTS

    EPA Science Inventory

    Induction of the membrane-associated organic solvent efflux system SrpABC of Pseudomonas putida S12 was examined by cloning a 312-bp DNA fragment, containing the srp promoter, in the broad-host-range reporter vector pKRZ-1. Compounds that are capable of inducing expression of the...

  18. Impairment of colour vision in workers exposed to organic solvents

    PubMed Central

    Semple, S; Dick, F; Osborne, A; Cherrie, J; Soutar, A; Seaton, A; Haites, N

    2000-01-01

    OBJECTIVES—To investigate loss of colour vision related to exposure to solvents and the role of three enzyme polymorphisms in modifying the risk in exposed workers.
METHODS—A sample was studied of 68 male dockyard workers and 42 male community controls with and without neuropsychological symptoms from a previous cross sectional study. Indices of cumulative and intensity based exposure to solvents were calculated for all subjects. Alcohol, drug, and smoking histories were obtained. Colour vision was tested by Lanthony D15d colour vision test. Genotype of glutathione S-transferase M1 and T1 and N-acetyltransferase 2 polymorphisms were determined.
RESULTS—The relation between impairment of colour vision and exposure to solvents was investigated with multiple regression techniques. Increasing annual exposure to solvents was significantly associated with reduced colour vision (p=0.029). Impairment of colour vision was not associated with neuropsychological symptoms as measured by the Q16 solvent symptom questionnaire. No significant association was found between acquired impairment of colour vision and genetic polymorphisms when GSTM1, GSTT1 or NAT2 phenotypes were included in the analyses.
CONCLUSIONS—Exposure to mixed solvents is associated with impairment in colour vision, the risk increases with increasing exposure. The risk of impairment of colour vision was not altered in this study by the presence of different GSTM1, GSTT1 or NAT2 polymorphisms.


Keywords: colour vision; organic solvents; genetic polymorphisms PMID:10935938

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Wood Building Products Pt. 63, Subpt. QQQQ, Table 5 Table 5 to Subpart QQQQ of Part 63—Default Organic.... Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic HAP, percent by mass...

  20. Acquired intolerance to organic solvents and results of vestibular testing

    SciTech Connect

    Gyntelberg, F.; Vesterhauge, S.; Fog, P.; Isager, H.; Zillstorff, K.

    1986-01-01

    Among 160 consecutive patients referred to the Clinic of Occupational Medicine, Rigshospitalet, for symptoms connected with exposure to organic solvents, 20 exhibited symptoms of acquired intolerance to minor amounts of organic solvents. Later, an additional 30 consecutive patients with symptoms of acquired intolerance were included, yielding a total of 43 men and 7 women. The characteristics of the clinical syndrome described are complaints of dizziness, nausea, and weakness after exposure to minimal solvent vapor concentrations. After having tolerated long-term occupational exposure to moderate or high air concentrations of various organic solvents, the patients became intolerant within a short period of time. Since dizziness was a frequent complaint, we tried to obtain a measure of the patients' complaints using vestibular tests. As a diagnostic test the combined vestibular tests had a sensitivity of 0.55 and a specificity of 0.87. No differences between patients with and without intolerance could be detected by the vestibular tests used. We conclude that acquired intolerance to organic solvents is a new but characteristic and easily recognizable syndrome, often with severe consequences for the patient's working ability.

  1. Organic solvents identify specific ligand binding sites on protein surfaces.

    PubMed

    Liepinsh, E; Otting, G

    1997-03-01

    Enzymes frequently recognize substrates and pharmaceutical drugs through specific binding interactions in deep pockets on the protein surface. We show how the specificity-determining substrate binding site of hen egg-white lysozyme (HEWL) can be readily identified in aqueous solution by nuclear magnetic resonance spectroscopy using small organic solvent molecules as detection probes. Exchange of magnetization between the 1H nuclei of the protein and the ligands through dipole-dipole interactions is observed which allows the modeling of their position and orientation at the binding site. Combined with site-specific binding constants measured by titration experiments with different organic solvents, the method can provide important information for rational drug design. In addition, the lifetime of nonspecific interactions of HEWL with organic solvents is shown to be in the sub-nanosecond time range. PMID:9062927

  2. A novel hemin-based organic phase artificial enzyme electrode and its application in different hydrophobicity organic solvents.

    PubMed

    Ge, Pei-Yu; Zhao, Wei; Du, Ying; Xu, Jing-Juan; Chen, Hong-Yuan

    2009-03-15

    Based on the newly discovered artificial enzyme formed by mixing hemin with supramolecular hydrogels via the self-assembly of amphiphilic oligopeptides, we prepared a novel organic phase artificial enzyme electrode by coating the artificial enzyme on an electrode which was then covered with sodium alginate for protection. Scanning electron micrograph showed that the supramolecular hydrogel kept its nanofibers structure on the electrode surface. Hemin dispersed in the supermolecular hydrogel as monomer greatly promotes its direct electrochemistry behavior in organic solvents. At the same time, this electrode exhibited higher electrocatalytic ability to tert-butyl hydroperoxide (TBHP) than free hemin modified electrode (free hemin mainly present as dimer). As low as 27 microM TBHP could be detected with a linear range from 6.6 x 10(-5) to 1.27 x 10(-2)M via amperometric method. The biosensor can reach 95% of the steady-state current in about 10+/-2s. More importantly, it can be applied in both hydrophilic and hydrophobic solvents without adding extra buffer or mediators to them that cannot be received by most traditional organic phase enzyme electrodes. This unique property greatly promotes the development of the organic phase enzyme electrodes by facilitating the detection of different kinds of substrates of the hemin-based artificial enzyme soluble in hydrophilic and hydrophobic solvents. The artificial enzyme electrode was successfully used to determine organic peroxides in body lotion samples.

  3. Poly(ionic liquid) superabsorbent for polar organic solvents.

    PubMed

    Horne, W Jeffrey; Andrews, Mary A; Terrill, Kelsey L; Hayward, Spenser S; Marshall, Jeannie; Belmore, Kenneth A; Shannon, Matthew S; Bara, Jason E

    2015-05-01

    A simple, polymerized ionic liquid (poly(IL)) based on methylimidazolium cations tethered to a polystyrene backbone exhibits superabsorbent behavior toward polar organic solvents, most notably propylene carbonate (PC) and dimethyl sulfoxide (DMSO), wherein the poly(IL) was observed to swell more than 390 and 200 times (w/w) its original mass, yet absorbs negligible quantities of water, hexanes, and other solvents, many of which were miscible with the IL monomer. Although solubility parameters and dielectric constants are typically used to rationalize such behaviors, we find that poly(IL)-solvent compatibility is most clearly correlated to solvent dipole moment. Poly(IL) superabsorbency is not reliant upon the addition of a cross-linking agent. PMID:25893981

  4. Universal organic solvent-water partition coefficient model

    PubMed

    Torrens

    2000-03-01

    A method that permits a semiquantitative estimate of the partitioning of any solute between any two media is presented. As an example, the organic solvent-water partition coefficients P are calculated. Program GSCAP is written as a version of Pascal's SCAP program. The only needed parameters are the dielectric constant and molecular volume of the organic solvent. The log P results are compared with the Pomona database. The average absolute deviation is 1.48 log units and the standard deviation is 1.66 log units.

  5. INFLUENCE OF ORGANIC BUFFERS ON BACTERIOCIN PRODUCTION BY STREPTOCOCCUS THERMOPHILUS ST110

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of the organic buffer salts MES, MOPS and PIPES on the growth of S. thermophilus ST110, medium pH and accumulation of the antipediococcal bacteriocin thermophilin 110 were evaluated in whey permeate media over a period of 24 h. In non buffered medium, thermophilin 110 production at 37°C ...

  6. Can Dispersion Forces Govern Aromatic Stacking in an Organic Solvent?

    PubMed

    Yang, Lixu; Brazier, John B; Hubbard, Thomas A; Rogers, David M; Cockroft, Scott L

    2016-01-18

    Experimental support for the dominance of van der Waals dispersion forces in aromatic stacking interactions occurring in organic solution is surprisingly limited. The size-dependence of aromatic stacking in an organic solvent was examined. The interaction energy was found to vary by about 7.5 kJ mol(-1) on going from a phenyl-phenyl to an anthracene-pyrene stack. Strikingly, the experimental data were highly correlated with dispersion energies determined using symmetry-adapted perturbation theory (SAPT), while the induction, exchange, electrostatic, and solvation energy components correlated poorly. Both the experimental data and the SAPT-dispersion energies gave high-quality correlations with the change in solvent accessible area upon complexation. Thus, the size-dependence of aromatic stacking interactions is consistent with the dominance of van der Waals dispersion forces even in the presence of a competing polarizable solvent. PMID:26632979

  7. Catalytic solvent delignification of agricultural residues: Organic catalysts.

    PubMed

    Ghose, T K; Pannir Selvam, P V; Ghosh, P

    1983-11-01

    The effects of moderate-temperature aqueous butanol pretreatment of rice straw on several organic catalysts have been studied. Maximum delignification was obtained with an aromatic organic acid catalyst. Presoaking of straw in aqueous improved delignification, particularly in high solid-liquid rations. However, due to the difficulty of penetration of lignin into the solvent phase, an increase in the solid-liquid ratio appears to affect delignification. A two-stage catalytic solvent process involving presoaking at 80 degrees C followed by delignification at 120 degrees C resulted in 83% removal of lignin in aqueous-butanol, whereas 75% lignin removal was possible in ethanol. Higher reduction in the crystallinity was possible with etanol. Lignin produced by the solvent process offers desirable physical properties for polymer applications compared to Kraft lignin.

  8. Can Dispersion Forces Govern Aromatic Stacking in an Organic Solvent?

    PubMed

    Yang, Lixu; Brazier, John B; Hubbard, Thomas A; Rogers, David M; Cockroft, Scott L

    2016-01-18

    Experimental support for the dominance of van der Waals dispersion forces in aromatic stacking interactions occurring in organic solution is surprisingly limited. The size-dependence of aromatic stacking in an organic solvent was examined. The interaction energy was found to vary by about 7.5 kJ mol(-1) on going from a phenyl-phenyl to an anthracene-pyrene stack. Strikingly, the experimental data were highly correlated with dispersion energies determined using symmetry-adapted perturbation theory (SAPT), while the induction, exchange, electrostatic, and solvation energy components correlated poorly. Both the experimental data and the SAPT-dispersion energies gave high-quality correlations with the change in solvent accessible area upon complexation. Thus, the size-dependence of aromatic stacking interactions is consistent with the dominance of van der Waals dispersion forces even in the presence of a competing polarizable solvent.

  9. Transitioning organic synthesis from organic solvents to water. What's your E Factor?

    PubMed Central

    Lipshutz, Bruce H.; Ghorai, Subir

    2014-01-01

    Traditional organic chemistry, and organic synthesis in particular, relies heavily on organic solvents, as most reactions involve organic substrates and catalysts that tend to be water-insoluble. Unfortunately, organic solvents make up most of the organic waste created by the chemical enterprise, whether from academic, industrial, or governmental labs. One alternative to organic solvents follows the lead of Nature: water. To circumvent the solubility issues, newly engineered “designer” surfactants offer an opportunity to efficiently enable many of the commonly used transition metal-catalyzed and related reactions in organic synthesis to be run in water, and usually at ambient temperatures. This review focuses on recent progress in this area, where such amphiphiles spontaneously self-aggregate in water. The resulting micellar arrays serve as nanoreactors, obviating organic solvents as the reaction medium, while maximizing environmental benefits. PMID:25170307

  10. Transitioning organic synthesis from organic solvents to water. What's your E Factor?

    PubMed

    Lipshutz, Bruce H; Ghorai, Subir

    2014-08-01

    Traditional organic chemistry, and organic synthesis in particular, relies heavily on organic solvents, as most reactions involve organic substrates and catalysts that tend to be water-insoluble. Unfortunately, organic solvents make up most of the organic waste created by the chemical enterprise, whether from academic, industrial, or governmental labs. One alternative to organic solvents follows the lead of Nature: water. To circumvent the solubility issues, newly engineered "designer" surfactants offer an opportunity to efficiently enable many of the commonly used transition metal-catalyzed and related reactions in organic synthesis to be run in water, and usually at ambient temperatures. This review focuses on recent progress in this area, where such amphiphiles spontaneously self-aggregate in water. The resulting micellar arrays serve as nanoreactors, obviating organic solvents as the reaction medium, while maximizing environmental benefits.

  11. 40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends

    Code of Federal Regulations, 2010 CFR

    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...

  12. 40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Contents of... Boat 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...

  13. 40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Contents of... Boat 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...

  14. Lipase catalyzed esterification of glycidol in organic solvents

    SciTech Connect

    Martins, J.F.; Nunes da Ponte, M.; Barreiros, S. . Centro de Tecnologia Quimica e Biologica)

    1993-08-05

    The authors studied the resolution of racemic glycidol through esterification with butyric acid catalyzed by porcine pancreatic lipase in organic media. A screening of seven solvents (log P values between 0.49 and 3.0, P being the n-octanol-water partition coefficient of the solvent) showed that neither log P nor the logarithm of the molar solubility of water in the solvent provides good correlations between enantioselectivity and the properties of the organic media. Chloroform was one of the best solvents as regards the enantiometic purity (e.p.) of the ester produced. In this solvent, the optimum temperature for the reaction was determined to be 35C. The enzyme exhibited maximum activity at a water content of 13 [plus minus] 2% (w/w). The enantiomeric purity obtained was 83 [plus minus] 2% of (S)-glycidol butyrate and did not depend on the alcohol concentration or the enzyme water content for values of these parameters up to 200 mM and 25% (w/w), respectively. The reaction was found to follow a BiBi mechanism.

  15. Lipase catalyzed esterification of glycidol in organic solvents.

    PubMed

    Martins, J F; Da Ponte, M N; Barreiros, S

    1993-08-01

    We studied the resolution of racemic glycidol through esterification with butyric acid catalyzed by porcine pancreatic lipase in organic media. A screening of seven solvents (log P values between 0.49 and 3.0, P being the n-octanol-water partition coefficient of the solvent) showed that neither log P nor the logarithm of the molar solubility of water in the solvent provides good correlations between enantioselectivity and the properties of the organic media. Chloroform was one of the best solvents as regards the enantiomeric purity (e. p.) of the ester produced. In this solvent, the optimum temperature for the reaction was determined to be 35 degrees C. The enzyme exhibited maximum activity at a water content of 13 +/- 2% (w/w). The enantiomeric purity obtained was 83 +/- 2% of (S)-glycidyl butyrate and did not depend on the alcohol concentration or the enzyme water content for values of these parameters up to 200 mM and 25% (w/w), respectively. The reaction was found to follow a BiBi mechanism.

  16. [Generic method for determination of volatile organic solvents in cosmetics].

    PubMed

    Da, Jing; Huang, Xianglu; Wang, Gangli; Cao, Jin; Zhang, Qingsheng

    2014-11-01

    A generic screening, confirmation and determination method was established based on 36 commonly used volatile organic solvents in cosmetics by headspace gas chromatography- mass spectrometry (GC-MS). This method included a database for pilot screening and identifi- cation of those solvents and their quantitative method. Pilot screening database was composed by two sections, one was household section built by two columns with opposite polarities (col- umn VF-1301 ms and DB-5 ms) using retention index in different column systems as qualitative parameter, and the other was NIST MS search version 2.0. Meanwhile, the determination method of the 36 volatile solvents was developed with GC-MS. Cosmetic samples were dissolved in water and transferred to a headspace vial. After 30 min equilibration at 60 °C, the samples were analyzed by GC-MS equipped with a capillary chromatographic column VF-1301 ms. The external calibration was used for quantification. The limits of detection were from 0.01 to 3.3 μg/g, and the recoveries were from 60.77% to 126.6%. This study provided a generic method for pilot screening, identification, and quantitation of volatile organic solvents in cosmetics, and may solve the problem that different analytical methods need to be developed for different targeted compounds and pilot screening for potential candidate solvent residues.

  17. 40 CFR 52.254 - Organic solvent usage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Air Quality Control Regions (the “Regions”), as described in 40 CFR part 81, dated July 1, 1979... been met. Editorial Note: For Federal Register citations affecting § 52.254, see the List of CFR... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Organic solvent usage. 52.254...

  18. 40 CFR 52.254 - Organic solvent usage.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Air Quality Control Regions (the “Regions”), as described in 40 CFR part 81, dated July 1, 1979... been met. Editorial Note: For Federal Register citations affecting § 52.254, see the List of CFR... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Organic solvent usage. 52.254...

  19. 40 CFR 52.254 - Organic solvent usage.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Air Quality Control Regions (the “Regions”), as described in 40 CFR part 81, dated July 1, 1979... been met. Editorial Note: For Federal Register citations affecting § 52.254, see the List of CFR... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Organic solvent usage. 52.254...

  20. 40 CFR 52.254 - Organic solvent usage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Air Quality Control Regions (the “Regions”), as described in 40 CFR part 81, dated July 1, 1979... been met. Editorial Note: For Federal Register citations affecting § 52.254, see the List of CFR... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Organic solvent usage. 52.254...

  1. Superfund Innovative Technology Evaluation: Demonstration Bulletin: Organic Extraction Utilizing Solvents

    EPA Science Inventory

    This technology utilizes liquified gases as the extracting solvent to remove organics, such as hydrocarbons, oil and grease, from wastewater or contaminated sludges and soils. Carbon dioxide is generally used for aqueous solutions, and propane is used for sediment, sludges and ...

  2. SOLVENT-FREE ACCELERATED ORGANIC SYNTHESES USING MICROWAVES

    EPA Science Inventory

    Abstract: A solvent-free approach for organic synthesis is described which involves microwave (MW) exposure of neat reactants (undiluted) either in presence of a catalyst or catalyzed by the surfaces of inexpensive and recyclable mineral supports such as alumina, silica, clay, or...

  3. Cardiovascular malformations and organic solvent exposure during pregnancy in Finland

    SciTech Connect

    Tikkanen, J.; Heinonen, O.P.

    1988-01-01

    In order to investigate the possible association between cardiovascular malformations and maternal exposure to organic solvents during the first trimester of pregnancy, 569 cases and 1,052 controls were retrospectively studied. The cases represented all infants with diagnosed cardiovascular malformations born in Finland in 1982-1984, and the controls were randomly selected from all normal births in the country during the same period. All mothers were interviewed approximately 3 months after delivery by a midwife using a structured questionnaire. Exposures to organic solvents at work during the first trimester of pregnancy were slightly more prevalent among the mothers of affected infants (10.4%) than among those of controls (7.8%). Logistic regression analysis of exposure to organic solvents showed an adjusted relative odds ratio of 1.3 (95% confidence interval, 0.8-2.2). In the analysis of ventricular septal defect, exposure to organic solvents showed an adjusted relative odds ratio of 1.5 (95% confidence interval, 1.0-3.7).

  4. Investigation of HNO2 Production in Solvent Extraction Organic Phases

    SciTech Connect

    Leigh R. Martin

    2014-09-01

    This document is a letter report that was prepared to meet FCR&D level 4 milestone M4FT-14IN0304054, “Investigate HNO2 production in solvent extraction organic phases.” This work was carried out under the auspices of the Fundamental Radiation Chemistry FCR&D work package. This document reports on an initial tests performed to follow HNO2 formation in reference flowsheet relevant organic phases.

  5. All solution processable organic photovoltaic cells using DMDCNQI as an organic N-type buffer layer.

    PubMed

    Yang, Eui Yeol; So, Byoung Min; Chung, Chan Moon; Oh, Se Young

    2012-01-01

    Organic photovoltaic cells consisting of ITO/PEDOT-PSS/P3HT:PCBM/TiO(x)/DMDCNQI/Al have been fabricated by using dip-coated DMDCNQI layer as a cathode buffer material. We have investigated the physical effects of charge transfer complex and wettability of DMDCNQI between TiO(x)/P3HT:PCBM layer and Al cathode electrode on the performance of organic photovoltaic cell. The photovoltaic cell fabricated with a dip-coated DMDCNQI layer exhibited almost similar performance compared to the device using conventional evaporated DMDCNQI layer. Especially, the power conversion efficiency of the prepared organic photovoltaic cell using TiO(x)/DMDCNQI layer was improved to 3.1%, which is mainly due to the decrease in the low contact resistance of organic-metal interface.

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Petroleum Solvent Groups 6 Table 6 to Subpart VVVV of Part 63 Protection of Environment ENVIRONMENTAL... Petroleum Solvent Groups As specified in § 63.5758(a)(6), when detailed organic HAP content data for solvent..., Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend.) 3 1% Xylene,...

  7. A QSPR study on the solvent-induced frequency shifts of acetone and dimethyl sulfoxide in organic solvents

    NASA Astrophysics Data System (ADS)

    Ou, Yu Heng; Chang, Chia Ming; Chen, Ying Shao

    2016-06-01

    In this study, solvent-induced frequency shifts (SIFS) in the infrared spectrum of acetone and dimethyl sulfoxide in organic solvents were investigated by using four types of quantum-chemical reactivity descriptors. The results showed that the SIFS of acetone is mainly affected by the electron-acceptance chemical potential and the maximum nucleophilic condensed local softness of organic solvents, which represent the electron flow and the polarization between acetone and solvent molecules. On the other hand, the SIFS of dimethyl sulfoxide changes with the maximum positive charge of hydrogen atom and the inverse of apolar surface area of solvent molecules, showing that the electrostatic and hydrophilic interactions are main mechanisms between dimethyl sulfoxide and solvent molecules. The introduction of the four-element theory model-based quantitative structure-property relationship approach improved the assessing quality and provided a basis for interpreting the solute-solvent interactions.

  8. A QSPR study on the solvent-induced frequency shifts of acetone and dimethyl sulfoxide in organic solvents.

    PubMed

    Ou, Yu Heng; Chang, Chia Ming; Chen, Ying Shao

    2016-06-01

    In this study, solvent-induced frequency shifts (SIFS) in the infrared spectrum of acetone and dimethyl sulfoxide in organic solvents were investigated by using four types of quantum-chemical reactivity descriptors. The results showed that the SIFS of acetone is mainly affected by the electron-acceptance chemical potential and the maximum nucleophilic condensed local softness of organic solvents, which represent the electron flow and the polarization between acetone and solvent molecules. On the other hand, the SIFS of dimethyl sulfoxide changes with the maximum positive charge of hydrogen atom and the inverse of apolar surface area of solvent molecules, showing that the electrostatic and hydrophilic interactions are main mechanisms between dimethyl sulfoxide and solvent molecules. The introduction of the four-element theory model-based quantitative structure-property relationship approach improved the assessing quality and provided a basis for interpreting the solute-solvent interactions. PMID:26994584

  9. 40 CFR Table 3 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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 Fraction for Solvents and Solvent Blends You may use the mass fraction values in the following table...

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

    PubMed

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

    2002-02-01

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

  11. Generalized Born and Explicit Solvent Models for Free Energy Calculations in Organic Solvents: Cyclodextrin Dimerization.

    PubMed

    Zhang, Haiyang; Tan, Tianwei; van der Spoel, David

    2015-11-10

    Evaluation of solvation (binding) free energies with implicit solvent models in different dielectric environments for biological simulations as well as high throughput ligand screening remain challenging endeavors. In order to address how well implicit solvent models approximate explicit ones we examined four generalized Born models (GB(Still), GB(HCT), GB(OBC)I, and GB(OBC)II) for determining the dimerization free energy (ΔG(0)) of β-cyclodextrin monomers in 17 implicit solvents with dielectric constants (D) ranging from 5 to 80 and compared the results to previous free energy calculations with explicit solvents ( Zhang et al. J. Phys. Chem. B 2012 , 116 , 12684 - 12693 ). The comparison indicates that neglecting the environmental dependence of Born radii appears acceptable for such calculations involving cyclodextrin and that the GB(Still) and GB(OBC)I models yield a reasonable estimation of ΔG(0), although the details of binding are quite different from explicit solvents. Large discrepancies between implicit and explicit solvent models occur in high-dielectric media with strong hydrogen bond (HB) interruption properties. ΔG(0) with the GB models is shown to correlate strongly to 2(D-1)/(2D+1) (R(2) ∼ 0.90) in line with the Onsager reaction field ( Onsager J. Am. Chem. Soc. 1936 , 58 , 1486 - 1493 ) but to be very sensitive to D (D < 10) as well. Both high-dielectric environments where hydrogen bonds are of interest and low-dielectric media such as protein binding pockets and membrane interiors therefore need to be considered with caution in GB-based calculations. Finally, a literature analysis of Gibbs energy of solvation of small molecules in organic liquids shows that the Onsager relation does not hold for real molecules since the correlation between ΔG(0) and 2(D-1)/(2D+1) is low for most solutes. Interestingly, explicit solvent calculations of the solvation free energy ( Zhang et al. J. Chem. Inf. Model . 2015 , 55 , 1192 - 1201 ) reproduce the weak

  12. Efficient organic solar cells processed from hydrocarbon solvents

    NASA Astrophysics Data System (ADS)

    Zhao, Jingbo; Li, Yunke; Yang, Guofang; Jiang, Kui; Lin, Haoran; Ade, Harald; Ma, Wei; Yan, He

    2016-02-01

    Organic solar cells have desirable properties, including low cost of materials, high-throughput roll-to-roll production, mechanical flexibility and light weight. However, all top-performance devices are at present processed using halogenated solvents, which are environmentally hazardous and would thus require expensive mitigation to contain the hazards. Attempts to process organic solar cells from non-halogenated solvents lead to inferior performance. Overcoming this hurdle, here we present a hydrocarbon-based processing system that is not only more environmentally friendly but also yields cells with power conversion efficiencies of up to 11.7%. Our processing system incorporates the synergistic effects of a hydrocarbon solvent, a novel additive, a suitable choice of polymer side chain, and strong temperature-dependent aggregation of the donor polymer. Our results not only demonstrate a method of producing active layers of organic solar cells in an environmentally friendly way, but also provide important scientific insights that will facilitate further improvement of the morphology and performance of organic solar cells.

  13. Rational enhancement of enzyme performance in organic solvents. Final technical report, 1992--1996

    SciTech Connect

    Klibanov, A.M.

    1996-12-31

    This research focused on the following: the dependence of enzymatic activity of several model hydrolases in nonaqueous solvents; control of substrate selectivity of the protease subtilisin Carlsberg by the solvent; control of catalytic activity and enantioselectivity of this enzyme in organic solvents by immobilization support; lipase-catalyzed acylation of sugars in anhydrous hydrophobic media; the possibility of accelerating enzymatic processes in organic solvents by certain cosolvents; whether lipase catalysis in organic solvents can be enhanced by introducing interfaces in the in the reaction medium; the structure of proteins suspended in organic solvents; improving enzymatic enantioselectivity in organic solvents; analyzing the plunge in enzymatic activity upon replacing water with organic solvents; and the structural basis for the phenomenon of molecular memory of imprinted proteins in organic solvents.

  14. Alterations in cognitive and psychological functioning after organic solvent exposure

    SciTech Connect

    Morrow, L.A.; Ryan, C.M.; Hodgson, M.J.; Robin, N. )

    1990-05-01

    Exposure to organic solvents has been linked repeatedly to alterations in both personality and cognitive functioning. To assess the nature and extent of these changes more thoroughly, 32 workers with a history of exposure to mixtures of organic solvents and 32 age- and education-matched blue-collar workers with no history of exposure were assessed with a comprehensive battery of neuropsychological tests. Although both groups were comparable on measures of general intelligence, significant differences were found in virtually all other cognitive domains tested (Learning and Memory, Visuospatial, Attention and Mental Flexibility, Psychomotor Speed). In addition, Minnesota Multiphasic Personality Inventories of exposed workers indicated clinically significant levels of depression, anxiety, somatic concerns and disturbances in thinking. The reported psychological distress was unrelated to degree of cognitive deficit. Finally, several exposure-related variables were associated with poorer performance on tests of memory and visuospatial ability.

  15. Gold recovery from organic solvents using galvanic stripping

    SciTech Connect

    Flores, C.; O`Keefe, T.J.

    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. Effect of temperature and solvent composition on acid dissociation equilibria, I: Sequenced (s)(s)pKa determination of compounds commonly used as buffers in high performance liquid chromatography coupled to mass spectroscopy detection.

    PubMed

    Padró, Juan M; Acquaviva, Agustín; Tascon, Marcos; Gagliardi, Leonardo G; Castells, Cecilia B

    2012-05-01

    A new automated and rapid potentiometric method for determining the effect of organic-solvent composition on pK(a) has been developed. It is based on the measurements of pH values of buffer solutions of variable solvent compositions using a combined glass electrode. Additions of small volumes of one precisely thermostated solution into another, both containing exactly the same analytical concentrations of the buffer components, can produce continuous changes in the solvent composition. Two sequences of potential measurements, one of increasing and the other of decreasing solvent content, are sufficient to obtain the pK(a) values of the acidic compound within the complete solvent-composition range in about 2h. The experimental design, procedures, and calculations needed to convert the measured pH into the thermodynamic pK(a) values are thoroughly discussed. This rapid and automated method allows the systematic study of the effect of solvent compositions and temperatures on the pK(a). It has been applied to study the dissociation constants of two monoprotic acids: formic acid and triethylamine:HCl in acetonitrile/water mixtures within the range from 0 to 90% (v/v) at temperatures between 20°C and 60°C. These volatile compounds are frequently used to control the pH of the mobile phase in HPLC, especially in methods coupled to mass-spectrometry detection. The obtained pK(a) values are in excellent agreement with those previously reported. The results were fitted to empirical functions between pK(a) and temperature and composition. These equations, which can be used to estimate the pK(a) of these substances at any composition and temperature, would be highly useful in practical work during chromatographic method development.

  17. Solvents induced ZnO nanoparticles aggregation associated with their interfacial effect on organic solar cells.

    PubMed

    Li, Pandeng; Jiu, Tonggang; Tang, Gang; Wang, Guojie; Li, Jun; Li, Xiaofang; Fang, Junfeng

    2014-10-22

    ZnO nanofilm as a cathode buffer layer has surface defects due to the aggregations of ZnO nanoparticles, leading to poor device performance of organic solar cells. In this paper, we report the ZnO nanoparticles aggregations in solution can be controlled by adjusting the solvents ratios (chloroform vs methanol). These aggregations could influence the morphology of ZnO film. Therefore, compact and homogeneous ZnO film can be obtained to help achieve a preferable power conversion efficiency of 8.54% in inverted organic solar cells. This improvement is attributed to the decreased leakage current and the increased electron-collecting efficiency as well as the improved interface contact with the active layer. In addition, we find the enhanced maximum exciton generation rate and exciton dissociation probability lead to the improvement of device performance due to the preferable ZnO dispersion. Compared to other methods of ZnO nanofilm fabrication, it is the more convenient, moderate, and effective to get a preferable ZnO buffer layer for high-efficiency organic solar cells.

  18. Polar organic solvent removal in microcosm constructed wetlands.

    PubMed

    Grove, Janet Kowles; Stein, Otto R

    2005-10-01

    Three polar organic solvents, acetone, tetrahydrofuran (THF) and 1-butanol, were added at 100 mg/l each to post-primary municipal wastewater in order to simulate a mixed waste stream. This mixture was applied to an experimental microcosm subsurface constructed wetland system consisting of replicates of Juncus effusus, Carex lurida, Iris pseudacorus, Pondeteria cordata and unplanted controls in a series of 14-day batch incubations over a yearlong period simulating a summer and winter season. 90% removal of 1-butanol typically took less than 3 days. 90% removal of acetone required from 5 to 10 days in summer and 10 to 14 days in winter. 90% removal of THF required at least 10 days and was frequently not achieved during the 14-day incubations. Initial experiments confirmed that the majority of solvent removal was via microbial bioremediation. Solvent removal was typically better in planted replicates, especially Juncus, regardless of season. The removal rate of all solvents was slower in winter, but the seasonal effect was most pronounced in the unplanted control replicates and least in the Carex and Juncus replicates. Plant and seasonal effects are believed to be due, in part, to variation in metabolic pathways induced by plant and seasonal variation in available root-zone oxygen. Variation in transpiration also influenced species and seasonal effects on THF removal, but not the other more biodegradable solvents. A model based on a prediction of plant uptake of nonionic dissolved chemicals suggests that as much as 39% of the THF in solution could have been removed through plant transpiration.

  19. Solubility of C60 and PCBM in Organic Solvents.

    PubMed

    Wang, Chun I; Hua, Chi C

    2015-11-12

    The ability to correlate fullerene solubility with experimentally or computationally accessible parameters can significantly facilitate nanotechnology nowadays for a wide range of applications, while providing crucial insight into optimum design of future fullerene species. To date, there has been no single relationship that satisfactorily describes the existing data clearly manifesting the effects of solvent species, system temperature, and isomer. Using atomistic molecular dynamics simulations on two standard fullerene species, C60 and PCBM ([6,6]-phenyl-C61-butyric acid methyl ester), in a representative series of organic solvent media (i.e., chloroform, toluene, chlorobenzene, 1,3-dichlorobenzene, and 1,2-dichlorobenzene), we show that a single time constant characterizing the dynamic stability of a tiny (angstrom-sized) solvation shell encompassing the fullerene particle can be utilized to effectively capture the known trends of fullerene solubility as reported in the literature. The underlying physics differs substantially between the two fullerene species, however. Although C60 was previously shown to be dictated by a diffusion-limited aggregation mechanism, the side-chain-substituted PCBM is demonstrated herein to proceed with an analogous reaction-limited aggregation with the "reaction rate" set by the fullerene rotational diffusivity in the medium. The present results suggest that dynamic quantities-in contrast to the more often employed, static ones-may provide an excellent means to characterize the complex (entropic and enthalpic) interplay between fullerene species and the solvent medium, shed light on the factors determining the solvent quality of a nanoparticle solution, and, in particular, offer a practical pathway to foreseeing optimum fullerene design and fullerene-solvent interactions. PMID:26488132

  20. 40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for... OOOO of Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass... organic HAP, percent by mass 1. Toluene 108-88-3 1.0 Toluene. 2. Xylene(s) 1330-20-7 1.0...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for... OOOO of Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass... organic HAP, percent by mass 1. Toluene 108-88-3 1.0 Toluene. 2. Xylene(s) 1330-20-7 1.0...

  2. 40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for... OOOO of Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass... organic HAP, percent by mass 1. Toluene 108-88-3 1.0 Toluene. 2. Xylene(s) 1330-20-7 1.0...

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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....

  4. 40 CFR Table 3 to Subpart Nnnn of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2010 CFR

    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....

  5. 40 CFR Table 6 to Subpart Vvvv of... - Default Organic HAP Contents of Petroleum Solvent Groups

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Petroleum Solvent Groups 6 Table 6 to Subpart VVVV of Part 63 Protection of Environment ENVIRONMENTAL... Contents of Petroleum Solvent Groups As specified in § 63.5758(a)(6), when detailed organic HAP content..., Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend.) 3...

  6. Enzyme catalysis in organic solvents: influence of water content, solvent composition and temperature on Candida rugosa lipase catalyzed transesterification.

    PubMed

    Herbst, Daniela; Peper, Stephanie; Niemeyer, Bernd

    2012-12-31

    In the present study the influence of water content, solvent composition and reaction temperature on the transesterification of 1-phenylpropan-2-ol catalyzed by Candida rugosa lipase was examined. Reactions were carried out in different mixtures of hexane and tetrahydrofurane. The studies showed that an increasing water content of the organic solvent results in an increasing enzyme activity and a decreasing enantiomeric excess. Furthermore, a significant influence of the solvent hydrophilicity both on the enzyme activity and on the enantiomeric excess was found. An increase in solvent hydrophilicity leads to a decrease of enzyme activity and an increase of the enantiomeric excess. This indicates that the enzyme becomes more selective with decreasing flexibility. Similar effects were found by variation of the reaction temperature. Taken together, the decrease in conversion and the increase in selectivity with increasing solvent hydrophilicity are induced by the different water contents on the enzyme surface and not by the solvent itself.

  7. Occupational Exposure to Organic Solvents during Bridge Painting

    PubMed Central

    Qian, Hua; Fiedler, Nancy; Moore, Dirk F.; Weisel, Clifford P.

    2010-01-01

    Exposure to volatile organic compounds (VOCs) from bridge painting was measured in New York City and New Jersey during the summer and fall seasons from 2005 to 2007. The effect of painting activities (paint coating layer, confinement setup, and application method) and meteorological conditions (temperature, humidity, and wind speed) on solvent exposure to aromatic, ketone, ester, and alkane compounds were individually evaluated. Mixed-effect models were used to examine the combination effects of these factors on the air concentration of total VOCs as the individual compound groups were not present in all samples. Air concentration associated with spraying was not affected by meteorological conditions since spraying was done in a confined space, thus reducing their impact on solvent air concentration. The mixed models for brushing and rolling samples included two fixed factors, i.e. application method and temperature, and one random factor, i.e. sampling day. An independent dataset (daily air samples) was used to validate the mixed model constructed for brushing and rolling samples. The regression line of the predicted values and actual measurements had a slope of 1.32 ± 0.15 for daily brushing and rolling samples, with almost all points being within the 95% confidence bands. The constructed model provides practical approaches for estimating the solvent exposure from brushing and rolling activities among construction painters. An adjusted mean air concentration derived from the activity-specific spray samples was the best estimate for that painting application. PMID:20354053

  8. Occupational exposure to organic solvents during bridge painting.

    PubMed

    Qian, Hua; Fiedler, Nancy; Moore, Dirk F; Weisel, Clifford P

    2010-06-01

    Exposure to volatile organic compounds (VOCs) from bridge painting was measured in New York City and New Jersey during the summer and fall seasons from 2005 to 2007. The effect of painting activities (paint coating layer, confinement setup, and application method) and meteorological conditions (temperature, humidity, and wind speed) on solvent exposure to aromatic, ketone, ester, and alkane compounds were individually evaluated. Mixed-effect models were used to examine the combination effects of these factors on the air concentration of total VOCs as the individual compound groups were not present in all samples. Air concentration associated with spraying was not affected by meteorological conditions since spraying was done in a confined space, thus reducing their impact on solvent air concentration. The mixed models for brushing and rolling samples included two fixed factors, i.e. application method and temperature, and one random factor, i.e. sampling day. An independent dataset (daily air samples) was used to validate the mixed model constructed for brushing and rolling samples. The regression line of the predicted values and actual measurements had a slope of 1.32 +/- 0.15 for daily brushing and rolling samples, with almost all points being within the 95% confidence bands. The constructed model provides practical approaches for estimating the solvent exposure from brushing and rolling activities among construction painters. An adjusted mean air concentration derived from the activity-specific spray samples was the best estimate for that painting application.

  9. Mixed Organic Solvents Induce Renal Injury in Rats

    PubMed Central

    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. PMID:23029287

  10. Interaction of protonated merocyanine dyes with amines in organic solvents

    NASA Astrophysics Data System (ADS)

    Ribeiro, Eduardo Alberton; Sidooski, Thiago; Nandi, Leandro Guarezi; Machado, Vanderlei Gageiro

    2011-10-01

    2,6-Diphenyl-4-(2,4,6-triphenylpyridinium-1-yl)phenolate ( 1a) and 4-[(1-methyl-4(1 H)-pyridinylidene)-ethylidene]-2,5-cyclohexadien-1-one ( 2a) were protonated in organic solvents (dichloromethane, acetonitrile, and DMSO) to form 1b and 2b, respectively. The appearance of the solvatochromic bands of 1a and 2a was studied UV-vis spectrophotometrically by deprotonation of 1b and 2b in solution in the presence of the following amines: aniline (AN), N-methylaniline (NMAN), N, N-dimethylaniline (NDAN), n-butylamine (BA), diethylamine (DEA), and triethylamine (TEA). Titrations of 1b and 2b with the amines were carried out and the binding constants were determined from the titration curves in each solvent, using a mathematical model adapted from the literature which considers the simultaneous participation of two dye: amine stoichiometries, 1:1 and 1:2. The data obtained showed the following base order for the two compounds in DMSO: BA > DEA > TEA, while aromatic amines did not cause any effect. In dichloromethane, the following base order for 1b was verified: TEA > DEA > BA ≫NDAN, while for 2b the order was: TEA > DEA > BA, suggesting that 1b is more acidic than 2b. The data in acetonitrile indicated for 1b and 2b the following order for the amines: DEA > TEA > BA. The diversity of the experimental data were explained based on a model that considers the level of interaction of the protonated dyes with the amines to be dependent on three aspects: (a) the basicity of the amine, which varies according to their molecular structure and the solvent in which it is dissolved, (b) the molecular structure of the dye, and (c) the solvent used to study the system.

  11. The dual role of lakes as buffers and amplifiers of dissolved organic matter temporal dynamics: Buffering transport and amplifying transformation

    NASA Astrophysics Data System (ADS)

    Ejarque, Elisabet; Schelker, Jakob; Khan, Samiullah; Hollaus, Lisa-Maria; Steniczka, Gertraud; Kainz, Martin; Battin, Tom

    2016-04-01

    Lakes that disrupt the flow of water and its constituents within the fluvial continuum can modify the downstream dynamics of dissolved organic matter (DOM). Potential causes of this change may include the hydrological buffering capacity of lakes relative to streams and rivers and the amplification of biotic processes. To test this hypothesis, we measured DOM quantity and quality at the inflow and outflow of sub-alpine Lake Lunz (Lower Austria) during one year. DOM quality was characterised using optical metrics indicative of the humic-like composition (fluorescence peak C), humification (HIX), and aromaticity (SUVA) degree, predominance of autochthonous components (BIX), and average molecular weight (E2:E3). Total annual variability was found to be lower in the outflow compared with the inflow (SDout:SDin < 1) for dissolved organic carbon (DOC) concentration and HIX. These variables showed a minimal seasonal variation in both inflow and outflow, together with a more accentuated response to hydrology in the inflow. Mean DOC concentration was significantly higher in the outflow (1.70 ± 0.14 mg L‑1) than in the inflow (1.3 ± 0.25 mg L‑1), and this pattern was only occasionally reversed during high flow. By contrast, the total annual variability of peak C, SUVA, BIX and E2:E3 was higher in the outflow than in the inflow (SDout:SDin > 1). This was due to the large seasonal variability in the outflow, which contrasted with a reduced temporal dynamics in the inflow. Combined, this created a shift from similar inflow-outflow DOM characteristics during winter, to uncoupled DOM characteristics during summer. This uncoupling consisted in a higher signal of the autotrophic origin of DOM, a lower average molecular weight, as well as a lower aromatic and humic-like content in the outflow. Overall, these results highlight the role of the Lake Lunz as a DOC source and as a buffer of hydrological pulses of DOC export. Moreover, results emphasise the capacity of the lake to

  12. Exciton-blocking phosphonic acid-treated anode buffer layers for organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Zimmerman, Jeramy D.; Song, Byeongseop; Griffith, Olga; Forrest, Stephen R.

    2013-12-01

    We demonstrate significant improvements in power conversion efficiency of bilayer organic photovoltaics by replacing the exciton-quenching MoO3 anode buffer layer with an exciton-blocking benzylphosphonic acid (BPA)-treated MoO3 or NiO layer. We show that the phosphonic acid treatment creates buffers that block up to 70% of excitons without sacrificing the hole extraction efficiency. Compared to untreated MoO3 anode buffers, BPA-treated NiO buffers exhibit a ˜ 25% increase in the near-infrared spectral response in diphenylanilo functionalized squaraine (DPSQ)/C60-based bilayer devices, increasing the power conversion efficiency under 1 sun AM1.5G simulated solar illumination from 4.8 ± 0.2% to 5.4 ± 0.3%. The efficiency can be further increased to 5.9 ± 0.3% by incorporating a highly conductive exciton blocking bathophenanthroline (BPhen):C60 cathode buffer. We find similar increases in efficiency in two other small-molecule photovoltaic systems, indicating the generality of the phosphonic acid-treated buffer approach to enhance exciton blocking.

  13. Volatile buffers can override the "pH memory" of subtilisin catalysis in organic media.

    PubMed

    Zacharis, E; Halling, P J; Rees, D G

    1999-02-16

    The protonation state and activity of enzymes in low-water media are affected by the aqueous pH before drying ("pH memory"). However, both protonation and activity will change if buffer ions can be removed as volatile or organic-extractable weak acids or bases. With NH4OOCH buffers, in which both ions can be removed, pH memory disappears completely for subtilisin-catalyzed transesterification in hexane. Only weak pH memory is found with buffers having one volatile component, NH4-phosphate and NaOOCH. The changes in ionization state result from proton exchanges like Protein-COO-NH4+ --> Protein-COOH + NH3 (g) and Protein-NH3+HCOO- --> Protein-NH2 + HOOCH (g). An equivalent, complementary picture is that net charges on the protein and buffer ions must remain equal and opposite. With NaOOCH buffers, loss of some HCOO- ions gives a more negative net charge on the protein, balanced by the excess Na+. With NH4-phosphate buffers, loss of NH3 gives protein with a more positive net charge. The resulting catalytic activities were high and low, respectively, similar to those after drying from Na-phosphate buffers of optimal (8.5) and acid pH. All of the above effects have been demonstrated for both covalently immobilized subtilisin and the lyophilized free enzyme. Subtilisin lyophilized from NH4OOCH buffers gave pH approximately 4 after redissolution in water, probably because removal of HCOO- counterions remains incomplete. The resulting catalytic activity was low. The effects are discussed in relation to the possible locations, in low-dielectric media, of the positive charge that balances the net negative catalytic triad in active subtilisin. PMID:9990001

  14. S5 Lipase: an organic solvent tolerant enzyme.

    PubMed

    Rahman, Raja Noor Zaliha Abdul; Baharum, Syarul Nataqain; Salleh, Abu Bakar; Basri, Mahiran

    2006-12-01

    In this study, an organic solvent tolerant bacterial strain was isolated. This strain was identified as Pseudomonas sp. strain S5, and was shown to degrade BTEX (Benzene, Toluene, Ethyl-Benzene, and Xylene). Strain S5 generates an organic solvent-tolerant lipase in the late logarithmic phase of growth. Maximum lipase production was exhibited when peptone was utilized as the sole nitrogen source. Addition of any of the selected carbon sources to the medium resulted in a significant reduction of enzyme production. Lower lipase generation was noted when an inorganic nitrogen source was used as the sole nitrogen source. This bacterium hydrolyzed all tested triglycerides and the highest levels of production were observed when olive oil was used as a natural triglyceride. Basal medium containing Tween 60 enhanced lipase production to the most significant degree. The absence of magnesium ions (Mg2+) in the basal medium was also shown to stimulate lipase production. Meanwhile, an alkaline earth metal ion, Na+, was found to stimulate the production of S5 lipase.

  15. High exposures to organic solvents among graffiti removers.

    PubMed

    Anundi, H; Lind, M L; Friis, L; Itkes, N; Langworth, S; Edling, C

    1993-01-01

    The exposure to organic solvents among 12 graffiti removers was studied. Health effects were also assessed by structured interview and a symptom questionnaire. Blood and urine samples were collected at the end of the day of air sampling. The concentrations of dichloromethane, glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone in the breathing zone of each worker were measured during one working day. The 8-h time-weighted average exposure to dichloromethane ranged from 18 to 1200 mg/m3. The Swedish Permissible Exposure Limit value for dichloromethane is 120 mg/m3. The air concentrations of glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone were low or not detectable. No exposure-related deviations in the serum concentrations of creatinine, aspartate transaminase, alanine transaminase, gamma-glutamyl transpeptidase or hyaluronan or the urine concentrations of alpha 1-microglobulin, beta 2-microglobulin or N-acetyl-beta-glucosaminidase were found. Irritative symptoms of the eyes and upper respiratory tract were more prevalent than in the general population. This study demonstrates that old knowledge about work hazards is not automatically transferred to new professions. Another aspect is that the public is also exposed as the job is performed during daytime in underground stations. At least for short periods, bystanders may be exposed to high concentrations of organic solvent vapours. People with predisposing conditions, e.g. asthmatics, may risk adverse reactions. PMID:8144235

  16. High exposures to organic solvents among graffiti removers.

    PubMed

    Anundi, H; Lind, M L; Friis, L; Itkes, N; Langworth, S; Edling, C

    1993-01-01

    The exposure to organic solvents among 12 graffiti removers was studied. Health effects were also assessed by structured interview and a symptom questionnaire. Blood and urine samples were collected at the end of the day of air sampling. The concentrations of dichloromethane, glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone in the breathing zone of each worker were measured during one working day. The 8-h time-weighted average exposure to dichloromethane ranged from 18 to 1200 mg/m3. The Swedish Permissible Exposure Limit value for dichloromethane is 120 mg/m3. The air concentrations of glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone were low or not detectable. No exposure-related deviations in the serum concentrations of creatinine, aspartate transaminase, alanine transaminase, gamma-glutamyl transpeptidase or hyaluronan or the urine concentrations of alpha 1-microglobulin, beta 2-microglobulin or N-acetyl-beta-glucosaminidase were found. Irritative symptoms of the eyes and upper respiratory tract were more prevalent than in the general population. This study demonstrates that old knowledge about work hazards is not automatically transferred to new professions. Another aspect is that the public is also exposed as the job is performed during daytime in underground stations. At least for short periods, bystanders may be exposed to high concentrations of organic solvent vapours. People with predisposing conditions, e.g. asthmatics, may risk adverse reactions.

  17. Characterizing DNA Condensation and Conformational Changes in Organic Solvents

    PubMed Central

    Ke, Fuyou; Luu, Yen Kim; Hadjiargyrou, Michael; Liang, Dehai

    2010-01-01

    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. PMID:20949017

  18. Direct extraction of genomic DNA from maize with aqueous ionic liquid buffer systems for applications in genetically modified organisms analysis.

    PubMed

    Gonzalez García, Eric; Ressmann, Anna K; Gaertner, Peter; Zirbs, Ronald; Mach, Robert L; Krska, Rudolf; Bica, Katharina; Brunner, Kurt

    2014-12-01

    To date, the extraction of genomic DNA is considered a bottleneck in the process of genetically modified organisms (GMOs) detection. Conventional DNA isolation methods are associated with long extraction times and multiple pipetting and centrifugation steps, which makes the entire procedure not only tedious and complicated but also prone to sample cross-contamination. In recent times, ionic liquids have emerged as innovative solvents for biomass processing, due to their outstanding properties for dissolution of biomass and biopolymers. In this study, a novel, easily applicable, and time-efficient method for the direct extraction of genomic DNA from biomass based on aqueous-ionic liquid solutions was developed. The straightforward protocol relies on extraction of maize in a 10 % solution of ionic liquids in aqueous phosphate buffer for 5 min at room temperature, followed by a denaturation step at 95 °C for 10 min and a simple filtration to remove residual biopolymers. A set of 22 ionic liquids was tested in a buffer system and 1-ethyl-3-methylimidazolium dimethylphosphate, as well as the environmentally benign choline formate, were identified as ideal candidates. With this strategy, the quality of the genomic DNA extracted was significantly improved and the extraction protocol was notably simplified compared with a well-established method. PMID:25381609

  19. Direct extraction of genomic DNA from maize with aqueous ionic liquid buffer systems for applications in genetically modified organisms analysis.

    PubMed

    Gonzalez García, Eric; Ressmann, Anna K; Gaertner, Peter; Zirbs, Ronald; Mach, Robert L; Krska, Rudolf; Bica, Katharina; Brunner, Kurt

    2014-12-01

    To date, the extraction of genomic DNA is considered a bottleneck in the process of genetically modified organisms (GMOs) detection. Conventional DNA isolation methods are associated with long extraction times and multiple pipetting and centrifugation steps, which makes the entire procedure not only tedious and complicated but also prone to sample cross-contamination. In recent times, ionic liquids have emerged as innovative solvents for biomass processing, due to their outstanding properties for dissolution of biomass and biopolymers. In this study, a novel, easily applicable, and time-efficient method for the direct extraction of genomic DNA from biomass based on aqueous-ionic liquid solutions was developed. The straightforward protocol relies on extraction of maize in a 10 % solution of ionic liquids in aqueous phosphate buffer for 5 min at room temperature, followed by a denaturation step at 95 °C for 10 min and a simple filtration to remove residual biopolymers. A set of 22 ionic liquids was tested in a buffer system and 1-ethyl-3-methylimidazolium dimethylphosphate, as well as the environmentally benign choline formate, were identified as ideal candidates. With this strategy, the quality of the genomic DNA extracted was significantly improved and the extraction protocol was notably simplified compared with a well-established method.

  20. Peptide synthesis of aspartame precursor using organic-solvent-stable PST-01 protease in monophasic aqueous-organic solvent systems.

    PubMed

    Tsuchiyama, Shotaro; Doukyu, Noriyuki; Yasuda, Masahiro; Ishimi, Kosaku; Ogino, Hiroyasu

    2007-01-01

    The PST-01 protease is a metalloprotease that has zinc ion at the active center and is very stable in the presence of water-soluble organic solvents. The reaction rates and the equilibrium yields of the aspartame precursor N-carbobenzoxy-L-aspartyl-L-phenylalanine methyl ester (Cbz-Asp-Phe-OMe) synthesis from N-carbobenzoxy-L-aspartic acid (Cbz-Asp) and L-phenylalanine methyl ester (Phe-OMe) in the presence of water-soluble organic solvents were investigated under various conditions. Higher reaction rate and yield of Cbz-Asp-Phe-OMe were attained by the PST-01 protease when 30 mM Cbz-Asp and 500 mM Phe-OMe were used. The maximum reaction rate was obtained pH 8.0 and 37 degrees C. In the presence of dimethylsulfoxide (DMSO), glycerol, methanol, and ethylene glycol, higher reaction rates were obtained. The equilibrium yield was the highest in the presence of DMSO. The equilibrium yield of Cbz-Asp-Phe-OMe using the PST-01 protease attained 83% in the presence of 50% (v/v) DMSO.

  1. Continuous hydrolysis of olive oil by immobilized lipase in organic solvent.

    PubMed

    Yang, D; Rhee, J S

    1992-09-01

    Lipase (EC 3.1.1.3) from Candida rugosa was immobilized with DEAE-Sephadex A50, Sephadex G50, Sephadex LH-20, Amberlite IRA94, and Amberlite XAD-7. The enzyme immobilized with DEAE-Sephadex A50 was found to be most effective for continuous hydrolysis of olive oil in isooctane. For the continuous reaction, 0.2 g of dry immobilized enzyme was swollen with predetermined amount of water, and packed in a glass column reactor. When the organic solvent (Isooctane) containing olive oil substrate was co-currently fed with aqueous buffer, the two phases were evenly distributed throughout the packed bed without surfactant supplement or prior mixing of the two phases. A small amount of the surfactant (AOT) was used only in packing procedure, and no additional surfactant was necessary thereafter. Effects of initial water content of the swollen gel, buffer types, and strength were examined in the continuous reaction. Our results suggest that the operational half-life was affected by desorption of the bound enzyme. Under the conditions of 20% olive oil in isooctane and 25 mM triethanolamine buffer (pH 7.0), operational half life was 220 h at 30 degrees C. The reactor was also operable with n-hexane, but the operational stability of the immobilized enzyme in n-hexane was only half of that in isooctane. Our results indicate that various enzyme carrier having hydrophilic or amphiphilic properties could be used for two-phase continuous reaction in packed-bed column, reactor without any surfactant supply or prior dispersion of the two immiscible phases. PMID:18601176

  2. Improving performance of inverted organic solar cells using ZTO nanoparticles as cathode buffer layer

    NASA Astrophysics Data System (ADS)

    Tsai, Meng-Yen; Cheng, Wen-Hui; Jeng, Jiann-Shing; Chen, Jen-Sue

    2016-06-01

    In this study, a low-temperature solution-processed zinc tin oxide (ZTO) films are successfully utilized as the cathode buffer layer in the inverted organic P3HT:PCBM bulk heterojunction solar cells. ZTO film cathode buffer layer with an appropriate Sn-doping concentration outperforms the zinc oxide (ZnO) film with an improved power conversion efficiency (1.96% (ZTO film) vs. 1.56% (ZnO film)). Furthermore, ZTO nanoparticles (NPs) are also synthesized via low-temperature solution route and the device with ZTO NPs buffer layer exhibits a significant improvement in device performance to reach a PCE of 2.60%. The crystallinity of the cathode buffer layer plays an influential factor in the performance. From impedance spectroscopy analysis, a correlation between short circuit current (Jsc), carrier life time (τavg) and, thus, PCE is observed. The interplay between composition and crystallinity of the cathode buffer layers is discussed to find their influences on the solar cell performance.

  3. Major neurological disease and occupational exposure to organic solvents.

    PubMed

    Seaton, A; Jellinek, E H; Kennedy, P

    1992-09-01

    Five patients are described who presented with major organic brain disease affecting one or more of pyramidal and extrapyramidal tracts, cerebellum, and higher cortical functions. All had a history of 10 years or more of regular occupational exposure to solvents in confined spaces, three in painting inside ships and the others in weapons maintenance and printing. All had been regularly exposed to high air vapour peaks as well as to skin contamination. Four showed some evidence of improvement after the exposure ceased. None was initially suspected of having a toxic encephalopathy by the consultant to whom he was referred. The spectrum of neurological disease presented by these men mirrors closely that described in solvent abusers. All were forced by illness to retire from their work, a circumstance which might have in the past have led to such conditions being missed in cross-sectional studies, which in general have not shown evidence of major disease. We suggest that when such disease occurs nowadays, its cause is usually not suspected. Further epidemiological study of the problem is necessary.

  4. Characterization of nicergoline polymorphs crystallized in several organic solvents.

    PubMed

    Malaj, Ledjan; Censi, Roberta; Capsoni, Doretta; Pellegrino, Luca; Bini, Marcella; Ferrari, Stefania; Gobetto, Roberto; Massarotti, Vincenzo; Di Martino, Piera

    2011-07-01

    Nicergoline (NIC), a poorly water-soluble semisynthetic ergot derivative, was crystallized from several organic solvents, obtaining two different polymorphic forms, the triclinic form I and the orthorhombic form II. NIC samples were then characterized by several techniques such as (13)C cross-polarization magic angle spinning solid-state spectroscopy, room-temperature and high-temperature X-ray powder diffraction, differential scanning calorimetry, and by analysis of weight loss, solvent content, powder density, morphology, and particle size. Solubility and intrinsic dissolution rates determined for the two polymorphic forms in water and hydrochloride solutions (HCl 0.1 N) were always higher for form II than for form I, which is actually the form used for the industrial preparation of NIC medicinal products. Preformulation studies might encourage industry for the evaluation of polymorph II, as it is more suitable for pharmaceutical applications. Results in drug delivery, as well as those obtained by the above-mentioned techniques, and the application of Burger-Ramberger's rules make it possible to conclude that there is a thermodynamic relation of monotropy between the two polymorphs. This last assumption may help formulators in predicting the relative stability of the two forms. PMID:21254066

  5. Solvent Effects on Electronic Excitations of an Organic Chromophore.

    PubMed

    Zuehlsdorff, T J; Haynes, P D; Hanke, F; Payne, M C; Hine, N D M

    2016-04-12

    In this work we study the solvatochromic shift of a selected low-energy excited state of alizarin in water by using a linear-scaling implementation of large-scale time-dependent density functional theory (TDDFT). While alizarin, a small organic dye, is chosen as a simple example of solute-solvent interactions, the findings presented here have wider ramifications for the realistic modeling of dyes, paints, and pigment-protein complexes. We find that about 380 molecules of explicit water need to be considered in order to yield an accurate representation of the solute-solvent interaction and a reliable solvatochromic shift. By using a novel method of constraining the TDDFT excitation vector, we confirm that the origin of the slow convergence of the solvatochromic shift with system size is due to two different effects. The first factor is a strong redshift of the excitation due to an explicit delocalization of a small fraction of the electron and the hole from the alizarin onto the water, which is mainly confined to within a distance of 7 Å from the alizarin molecule. The second factor can be identified as long-range electrostatic influences of water molecules beyond the 7 Å region on the ground-state properties of alizarin. We also show that these electrostatic influences are not well reproduced by a QM/MM model, suggesting that full QM studies of relatively large systems may be necessary in order to obtain reliable results. PMID:26967019

  6. Characterization of nicergoline polymorphs crystallized in several organic solvents.

    PubMed

    Malaj, Ledjan; Censi, Roberta; Capsoni, Doretta; Pellegrino, Luca; Bini, Marcella; Ferrari, Stefania; Gobetto, Roberto; Massarotti, Vincenzo; Di Martino, Piera

    2011-07-01

    Nicergoline (NIC), a poorly water-soluble semisynthetic ergot derivative, was crystallized from several organic solvents, obtaining two different polymorphic forms, the triclinic form I and the orthorhombic form II. NIC samples were then characterized by several techniques such as (13)C cross-polarization magic angle spinning solid-state spectroscopy, room-temperature and high-temperature X-ray powder diffraction, differential scanning calorimetry, and by analysis of weight loss, solvent content, powder density, morphology, and particle size. Solubility and intrinsic dissolution rates determined for the two polymorphic forms in water and hydrochloride solutions (HCl 0.1 N) were always higher for form II than for form I, which is actually the form used for the industrial preparation of NIC medicinal products. Preformulation studies might encourage industry for the evaluation of polymorph II, as it is more suitable for pharmaceutical applications. Results in drug delivery, as well as those obtained by the above-mentioned techniques, and the application of Burger-Ramberger's rules make it possible to conclude that there is a thermodynamic relation of monotropy between the two polymorphs. This last assumption may help formulators in predicting the relative stability of the two forms.

  7. Solvent-tolerance of fungi located on an interface between an agar plate and an organic solvent.

    PubMed

    Oda, Shinobu; Sugitani, Ayaka; Ohashi, Shinichi

    2014-01-01

    While 6 by 20 of type culture fungi could grow on an interface between organic solvent (log P, 4.12) and agar plate, 13 by 20 of strains could form a large colony after the removal of more toxic solvent, such as styrene (log P, 2.95) and tert-butyl acetate (log P, 1.76) because of viability of spores on the interface.

  8. Rapid carbon nanotubes suspension in organic solvents using organosilicon polymers.

    PubMed

    Dalcanale, Federico; Grossenbacher, Jonas; Blugan, Gurdial; Gullo, Maurizio R; Brugger, Jürgen; Tevaearai, Hendrik; Graule, Thomas; Kuebler, Jakob

    2016-05-15

    A strategy for a simple dispersion of commercial multi-walled carbon nanotubes (MWCNTs) using two organosilicones, polycarbosilane SMP10 and polysilazane Ceraset PSZ20, in organic solvents such as cyclohexane, tetrahydrofuran (THF), m-xylene and chloroform is presented. In just a few minutes the combined action of sonication and the presence of Pt(0) catalyst is sufficient to obtain a homogeneous suspension, thanks to the rapid hydrosilylation reaction between SiH groups of the polymer and the CNT sidewall. The as-produced suspensions have a particle size distribution <1μm and remain unchanged after several months. A maximum of 0.47 and 0.50mg/ml was achieved, respectively, for Ceraset in THF and SMP10 in chloroform. Possible applications as polymeric and ceramic thin films or aerogels are presented. PMID:26939076

  9. Peptide synthesis in neat organic solvents with novel thermostable proteases.

    PubMed

    Toplak, Ana; Nuijens, Timo; Quaedflieg, Peter J L M; Wu, Bian; Janssen, Dick B

    2015-06-01

    Biocatalytic peptide synthesis will benefit from enzymes that are active at low water levels in organic solvent compositions that allow good substrate and product solubility. To explore the use of proteases from thermophiles for peptide synthesis under such conditions, putative protease genes of the subtilase class were cloned from Thermus aquaticus and Deinococcus geothermalis and expressed in Escherichia coli. The purified enzymes were highly thermostable and catalyzed efficient peptide bond synthesis at 80°C and 60°C in neat acetonitrile with excellent conversion (>90%). The enzymes tolerated high levels of N,N-dimethylformamide (DMF) as a cosolvent (40-50% v/v), which improved substrate solubility and gave good conversion in 5+3 peptide condensation reactions. The results suggest that proteases from thermophiles can be used for peptide synthesis under harsh reaction conditions.

  10. Non-equilibrium plasma reactors for organic solvent destruction

    SciTech Connect

    Yang, C.L.; Beltran, M.R.; Kravets, Z.

    1997-12-31

    Two non-equilibrium plasma reactors were evaluated for their ability to destroy three widely used organic solvents, i.e., 2-butanone, toluene and ethyl acetate. The catalyzed plasma reactor (CPR) with 6 mm glass beads destroys 98% of 50 ppm toluene in air at 24 kV/cm and space velocities of 1,400 v/v/hr. Eighty-five percent of ethyl acetate and 2-butanone are destroyed under the same conditions. The tubular plasma reactor (TPR) has an efficiency of 10% to 20% lower than that of a CPR under the same conditions. The 1,400 v/v/hr in a CPR is equal to a residence time of 2.6 seconds in a TPR. The operating temperatures, corona characteristics, as well as the kinetics of VOC destruction in both TPR and CPR were studied.

  11. Evaluation of some water-miscible organic solvents for spray-drying enzymes and carbohydrates.

    PubMed

    Sass, Anke; Lee, Geoffrey

    2014-06-01

    The spray-drying behaviour of 16 water-miscible organic solvents on a bench-scale machine (Büchi B290 with inert loop) was determined under mild-to-moderate process conditions, namely inlet gas temperature of 130 °C and liquid feed flow rate of ≤3 mL/min. The solvents with boiling points below the inlet gas temperature could be fully dried (Group 1 solvents). The two exceptions were DMSO and DMF which despite their higher boiling points could be fully dried. The remaining solvents with boiling points above the inlet gas temperature were not fully dried during passage through the spray-dryer (Group 2 solvents). Trypsin and lysozyme when spray-dried from Group 1 solvent binary mixtures with water showed similar inactivation and residual water content, independent of solvent. The level of residual solvent was, however, strongly dependent on solvent. Trehalose (20%) and mannitol (10%) could be spray-dried from DMSO/water binary mixtures, but the amorphous disaccharide required higher inlet gas temperature. Trehalose/trypsin and mannitol/trypsin formulations showed differing degrees of protection against enzyme inactivation when spray-dried from Group 1 solvent binary mixtures with water. In all solvents the mannitol protected as well, if not better, than the trehalose. This study identifies some suitable organic solvents for spray-drying protein formulations, but also shows the difficulties of remaining organic solvent under the moderate inlet gas temperature used.

  12. Evaluation of some water-miscible organic solvents for spray-drying enzymes and carbohydrates.

    PubMed

    Sass, Anke; Lee, Geoffrey

    2014-06-01

    The spray-drying behaviour of 16 water-miscible organic solvents on a bench-scale machine (Büchi B290 with inert loop) was determined under mild-to-moderate process conditions, namely inlet gas temperature of 130 °C and liquid feed flow rate of ≤3 mL/min. The solvents with boiling points below the inlet gas temperature could be fully dried (Group 1 solvents). The two exceptions were DMSO and DMF which despite their higher boiling points could be fully dried. The remaining solvents with boiling points above the inlet gas temperature were not fully dried during passage through the spray-dryer (Group 2 solvents). Trypsin and lysozyme when spray-dried from Group 1 solvent binary mixtures with water showed similar inactivation and residual water content, independent of solvent. The level of residual solvent was, however, strongly dependent on solvent. Trehalose (20%) and mannitol (10%) could be spray-dried from DMSO/water binary mixtures, but the amorphous disaccharide required higher inlet gas temperature. Trehalose/trypsin and mannitol/trypsin formulations showed differing degrees of protection against enzyme inactivation when spray-dried from Group 1 solvent binary mixtures with water. In all solvents the mannitol protected as well, if not better, than the trehalose. This study identifies some suitable organic solvents for spray-drying protein formulations, but also shows the difficulties of remaining organic solvent under the moderate inlet gas temperature used. PMID:23596974

  13. Assembly and organization of poly(3-hexylthiophene) brushes and their potential use as novel anode buffer layers for organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Alonzo, José; Kochemba, W. Michael; Pickel, Deanna L.; Ramanathan, Muruganathan; Sun, Zhenzhong; Li, Dawen; Chen, Jihua; Sumpter, Bobby G.; Heller, William T.; Kilbey, S. Michael, II

    2013-09-01

    Buffer layers that control electrochemical reactions and physical interactions at electrode/film interfaces are key components of an organic photovoltaic cell. Here the structure and properties of layers of semi-rigid poly(3-hexylthiophene) (P3HT) chains tethered at a surface are investigated, and these functional systems are applied in an organic photovoltaic device. Areal density of P3HT chains is readily tuned through the choice of polymer molecular weight and annealing conditions, and insights from optical absorption spectroscopy and semiempirical quantum calculation methods suggest that tethering causes intrachain defects that affect co-facial π-stacking of brush chains. Because of their ability to modify oxide surfaces, P3HT brushes are utilized as an anode buffer layer in a P3HT-PCBM (phenyl-C61-butyric acid methyl ester) bulk heterojunction device. Current-voltage characterization shows a significant enhancement in short circuit current, suggesting the potential of these novel nanostructured buffer layers to replace the PEDOT:PSS buffer layer typically applied in traditional P3HT-PCBM solar cells.Buffer layers that control electrochemical reactions and physical interactions at electrode/film interfaces are key components of an organic photovoltaic cell. Here the structure and properties of layers of semi-rigid poly(3-hexylthiophene) (P3HT) chains tethered at a surface are investigated, and these functional systems are applied in an organic photovoltaic device. Areal density of P3HT chains is readily tuned through the choice of polymer molecular weight and annealing conditions, and insights from optical absorption spectroscopy and semiempirical quantum calculation methods suggest that tethering causes intrachain defects that affect co-facial π-stacking of brush chains. Because of their ability to modify oxide surfaces, P3HT brushes are utilized as an anode buffer layer in a P3HT-PCBM (phenyl-C61-butyric acid methyl ester) bulk heterojunction device

  14. Toxic effects of organic solvents on the growth of chlorella vulgaris and Selenastrum capicornutum

    SciTech Connect

    El Jay, A.

    1996-10-01

    Organic solvents can make their way into the environment as industrial wastes and components of pesticide formulations. In laboratory bioassays, the use of organic solvents is unavoidable since many pesticides and organic pollutants have low water solubilities and need to be dissolved in organic solvents prior to addition into experimental systems. So, one area of concern with laboratory bioassays is the stress imposed on test organisms by organic solvents. Most reports on the comparative toxicity of solvents towards test organisms deals with the effects of solvents on fish and aquatic invertebrates with some data available for blue-green algae and green algae. The US Environmental Protection Agency recommends maximum allowable limits of 0.05% solvent for acute tests and 0.01% for chronic tests but, in the literature, the nature of the solvent and the final concentration used vary among the different authors and are often higher than EPA limits due to problems associated with the use of small test volumes and toxicant solubility. Organic solvents can cause toxic effects on their own, but it has been also reported that they can interact with pesticides to alter toxicity. The first step in choosing a solvent for use in bioassays should be a detailed screening to identify solvents with inherently low toxicity to the test organism, followed by an interaction study (pesticide and solvent interactions) to choose the best concentration to use. The purpose of this study is to compare the inhibitory effects of our solvents used in pesticide bioassays towards the growth of two green algae. 18 refs., 4 figs., 1 tabs.

  15. DNA-catalyzed Henry reaction in pure water and the striking influence of organic buffer systems.

    PubMed

    Häring, Marleen; Pérez-Madrigal, Maria M; Kühbeck, Dennis; Pettignano, Asja; Quignard, Françoise; Díaz, David Díaz

    2015-01-01

    In this manuscript we report a critical evaluation of the ability of natural DNA to mediate the nitroaldol (Henry) reaction at physiological temperature in pure water. Under these conditions, no background reaction took place (i.e., control experiment without DNA). Both heteroaromatic aldehydes (e.g., 2-pyridinecarboxaldehyde) and aromatic aldehydes bearing strong or moderate electron-withdrawing groups reacted satisfactorily with nitromethane obeying first order kinetics and affording the corresponding β-nitroalcohols in good yields within 24 h. In contrast, aliphatic aldehydes and aromatic aldehydes having electron-donating groups either did not react or were poorly converted. Moreover, we discovered that a number of metal-free organic buffers efficiently promote the Henry reaction when they were used as reaction media without adding external catalysts. This constitutes an important observation because the influence of organic buffers in chemical processes has been traditionally underestimated.

  16. Water-enhanced solubility of carboxylic acids in organic solvents and its application to extraction processes

    SciTech Connect

    Starr, J.N. ); King, C.J. )

    1992-11-01

    This paper reports on solubilities of carboxylic acids in certain organic solvents which increase sharply as the concentration of water in the solvent increases. This phenomenon leads to a method of regeneration for solvent-extraction processes whereby coextracted water is selectively removed from the extract, such as by stripping, thereby precipitating the acid. The removal of a minor constituent to cause precipitation reduces energy consumption, in contrast with bulk removal of solvent. Solubilities of fumaric acid were measured in a number of organic solvents, with varying amounts of water in the organic phase. Cyclohexanone and methylcyclohexanone were chosen as solvents for which detailed solid-liquid and liquid-liquid equilibria were measured for adipic, fumaric, and succinic acids in the presence of varying concentrations of water, at both 25 and 45[degrees]C. Batch precipitation experiments were performed to demonstrate the processing concept and determine the relative volatility of water to solvent in the presence of carbon.

  17. 3D porous metal-organic framework exhibiting selective adsorption of water over organic solvents.

    PubMed

    Gu, Jin-Zhong; Lu, Wen-Guan; Jiang, Long; Zhou, Hong-Cai; Lu, Tong-Bu

    2007-07-23

    A 3D porous metal-organic framework (MOF) with 1D open channels has been constructed hydrothermally using Zn(II) and a rigid planar ligand IDC(3)- (imidazole-4,5-dicarboxylate). This MOF can adsorb water selectively over organic solvents and can be regenerated and reused. It also represents a rare example of a MOF with open channels that form/collapse reversibly upon hydration/dehydration.

  18. Relevance of an organic solvent for absorption of siloxanes.

    PubMed

    Ghorbel, Leila; Tatin, Romuald; Couvert, Annabelle

    2014-01-01

    A wide range of siloxanes exist but the most abundant in biogas are Hexamethyldisiloxane (L2) and Octamethyltrisiloxane (L3) as linear siloxanes and Octamethylcyclotetrasiloxane (D4) as a cyclic siloxane. In order to remove volatile organic compound from biogas, different processes can be used. A promising process for siloxane removal is their absorption in an organic solvent. In this work, three oils were tested to absorb the selected siloxanes: silicone oil 47V20, Seriola 1510 and Polyalphaolefin. Initially, the characterization of these oils was realized by measuring their viscosities and densities, depending on temperature. The second time, the absorption capacity of the siloxanes by selected oils was characterized through the determination of their Henry's constants, but also owing to the implementation of a wet-wall column. Both Henry's constants and removal efficiencies in continuous regime revealed that silicone oil (47V20) can be considered as the most efficient oil among the three selected siloxanes. Moreover, the cyclic siloxane (D4) showed more affinity with oils than linear siloxanes. Silicone oil 47V20 appeared to be the best oil (intermediate price 14 euro/L, low viscosity, low volatility, chemical inertness (no corrosion) and resistance to high and low temperatures).

  19. Regioselective self-acylating cyclodextrins in organic solvent

    PubMed Central

    Cho, Eunae; Yun, Deokgyu; Jeong, Daham; Im, Jieun; Kim, Hyunki; Dindulkar, Someshwar D.; Choi, Youngjin; Jung, Seunho

    2016-01-01

    Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrate in organic solvent. In the self-acylation, the most acidic OH group at the 2-position and the inclusion complexing ability of cyclodextrin were considered to be significant. The substrate preference was also observed in favor of the long-chain acyl group, which could be attributed to the inclusion ability of cyclodextrin cavity. Furthermore, using the model amphiphilic building block, 2-O-mono-lauryl β-cyclodextrin, the self-organized supramolecular architecture with nano-vesicular morphology in water was investigated by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. The cavity-type nano-assembled vesicle and the novel synthetic methods for the preparation of mono-acylated cyclodextrin should be of great interest with regard to drug/gene delivery systems, functional surfactants, and carbohydrate derivatization methods. PMID:27020946

  20. Regioselective self-acylating cyclodextrins in organic solvent

    NASA Astrophysics Data System (ADS)

    Cho, Eunae; Yun, Deokgyu; Jeong, Daham; Im, Jieun; Kim, Hyunki; Dindulkar, Someshwar D.; Choi, Youngjin; Jung, Seunho

    2016-03-01

    Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrate in organic solvent. In the self-acylation, the most acidic OH group at the 2-position and the inclusion complexing ability of cyclodextrin were considered to be significant. The substrate preference was also observed in favor of the long-chain acyl group, which could be attributed to the inclusion ability of cyclodextrin cavity. Furthermore, using the model amphiphilic building block, 2-O-mono-lauryl β-cyclodextrin, the self-organized supramolecular architecture with nano-vesicular morphology in water was investigated by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. The cavity-type nano-assembled vesicle and the novel synthetic methods for the preparation of mono-acylated cyclodextrin should be of great interest with regard to drug/gene delivery systems, functional surfactants, and carbohydrate derivatization methods.

  1. Regioselective self-acylating cyclodextrins in organic solvent.

    PubMed

    Cho, Eunae; Yun, Deokgyu; Jeong, Daham; Im, Jieun; Kim, Hyunki; Dindulkar, Someshwar D; Choi, Youngjin; Jung, Seunho

    2016-01-01

    Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrate in organic solvent. In the self-acylation, the most acidic OH group at the 2-position and the inclusion complexing ability of cyclodextrin were considered to be significant. The substrate preference was also observed in favor of the long-chain acyl group, which could be attributed to the inclusion ability of cyclodextrin cavity. Furthermore, using the model amphiphilic building block, 2-O-mono-lauryl β-cyclodextrin, the self-organized supramolecular architecture with nano-vesicular morphology in water was investigated by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. The cavity-type nano-assembled vesicle and the novel synthetic methods for the preparation of mono-acylated cyclodextrin should be of great interest with regard to drug/gene delivery systems, functional surfactants, and carbohydrate derivatization methods. PMID:27020946

  2. Relevance of an organic solvent for absorption of siloxanes.

    PubMed

    Ghorbel, Leila; Tatin, Romuald; Couvert, Annabelle

    2014-01-01

    A wide range of siloxanes exist but the most abundant in biogas are Hexamethyldisiloxane (L2) and Octamethyltrisiloxane (L3) as linear siloxanes and Octamethylcyclotetrasiloxane (D4) as a cyclic siloxane. In order to remove volatile organic compound from biogas, different processes can be used. A promising process for siloxane removal is their absorption in an organic solvent. In this work, three oils were tested to absorb the selected siloxanes: silicone oil 47V20, Seriola 1510 and Polyalphaolefin. Initially, the characterization of these oils was realized by measuring their viscosities and densities, depending on temperature. The second time, the absorption capacity of the siloxanes by selected oils was characterized through the determination of their Henry's constants, but also owing to the implementation of a wet-wall column. Both Henry's constants and removal efficiencies in continuous regime revealed that silicone oil (47V20) can be considered as the most efficient oil among the three selected siloxanes. Moreover, the cyclic siloxane (D4) showed more affinity with oils than linear siloxanes. Silicone oil 47V20 appeared to be the best oil (intermediate price 14 euro/L, low viscosity, low volatility, chemical inertness (no corrosion) and resistance to high and low temperatures). PMID:24600877

  3. Assembly and organization of poly(3-hexylthiophene) brushes and their potential use as novel anode buffer layers for organic photovoltaics.

    PubMed

    Alonzo, José; Kochemba, W Michael; Pickel, Deanna L; Ramanathan, Muruganathan; Sun, Zhenzhong; Li, Dawen; Chen, Jihua; Sumpter, Bobby G; Heller, William T; Kilbey, S Michael

    2013-10-01

    Buffer layers that control electrochemical reactions and physical interactions at electrode/film interfaces are key components of an organic photovoltaic cell. Here the structure and properties of layers of semi-rigid poly(3-hexylthiophene) (P3HT) chains tethered at a surface are investigated, and these functional systems are applied in an organic photovoltaic device. Areal density of P3HT chains is readily tuned through the choice of polymer molecular weight and annealing conditions, and insights from optical absorption spectroscopy and semiempirical quantum calculation methods suggest that tethering causes intrachain defects that affect co-facial π-stacking of brush chains. Because of their ability to modify oxide surfaces, P3HT brushes are utilized as an anode buffer layer in a P3HT-PCBM (phenyl-C₆₁-butyric acid methyl ester) bulk heterojunction device. Current-voltage characterization shows a significant enhancement in short circuit current, suggesting the potential of these novel nanostructured buffer layers to replace the PEDOT:PSS buffer layer typically applied in traditional P3HT-PCBM solar cells.

  4. Process for separating a fluid feed mixture containing hydrocarbon oil and an organic solvent

    SciTech Connect

    Bitter, J.G.A.; Haan, J.P.

    1989-03-07

    This patent describes a process for separating a fluid feed mixture containing a hydrocarbon lubricating base oil and an organic solvent selected from furfural and mixture of toluene and methyl ethyl ketone which process comprises subjecting the fluid feed mixture to reverse osmosis in a reverse osmosis zone with a membrane comprising a layer of a silicone polymer. The process provides a retentate stream having an organic solvent content higher than the feed mixture, and a permeate stream having an organic solvent content less than the amount of solvent in the feed mixture, and permits recovering hydrocarbon oil from the permeate stream.

  5. Studies on the Properties of Organic Photovoltaic Cells Using TiOx and DMDCNQI as Double Buffer Layers.

    PubMed

    Kim, Gyu Min; Han, Seong Hun; Oh, Se Young

    2015-02-01

    Various types of n-type buffer layers have been used in organic electronic devices. These buffer layers turned out to expedite carrier injection and reduce series resistance, leading to good performance of organic electronic devices. In our current work, we have fabricated organic photovoltaic (OPV) cells consisting of ITO/PEDOT:PSS/P3HT:PCBM/TiOx/DMDCNQI/AI which were fabricated in the presence of air. To incorporate the individual advantages of each n-type buffer layer, a DMDCNQI and TiOx layers were inserted to act as n-type double buffer layers. This leads to an increase of short-circuit current (JSC) and fill factor (FF) with good stability, in comparison to P3HT:PCBM based conventional cells. The results imply that the structures of double buffer layers can provide possible alternative to achieving high performance and air durability.

  6. High mobility organic thin-film transistors based on p-p heterojunction buffer layer

    NASA Astrophysics Data System (ADS)

    Qian, Xianrui; Wang, Tong; Yan, Donghang

    2013-10-01

    The p-p heterojunction of 5, 6, 11, 12-tetraphenylnaphthacene/vanadyl phthalocyanine, which has been used as the buffer layer, is demonstrated. The highest field-effect mobility is 5.1 cm2/Vs, which is one of the highest reported for polycrystalline rubrene thin film transistors. Current versus voltage characteristics of heterojunction diodes are utilized to investigate the charge injection mechanism, revealing the factors that bring about the improvement of carrier injection and the reduction of contact resistance. These results suggest that our approach is very promising to fabricate high performance organic thin-film transistors for practical applications in organic electronics.

  7. Epidemiology of organic solvents and connective tissue disease

    PubMed Central

    Garabrant, David H; Dumas, Constantine

    2000-01-01

    Case reports suggest that solvents are associated with various connective tissue diseases (systemic sclerosis, scleroderma, undifferentiated connective tissue disease, systemic lupus erythematosis, and rheumatoid arthritis), particularly systemic sclerosis. A small number of epidemiological studies have shown statistically significant but weak associations between solvent exposure, systemic sclerosis, and undifferentiated connective tissue disease. However, the interpretation of these positive findings is tempered by a lack of replication, an inability to specify which solvents convey risk, and an absence of increasing risk with increasing exposure. Existing studies, on aggregate, do not show conclusively that solvents (either as a group of chemicals or individual chemicals) are causally associated with any connective tissue disease. Further investigations should be carried out to replicate the positive existing findings and to specify the solvents and circumstances of exposure that carry risk. PMID:11094414

  8. Tertiary phase diagram of cellulose, ionic liquid and organic solvent

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Henderson, Doug; Tyagi, Madhusudan; Mao, Yimin; Briber, Robert M.; Wang, Howard

    Cellulose is the most abundant natural polymer on earth, and widely used in products from clothing to paper. Fundamental understanding of molecular solutions of cellulose is the key to realize advanced technologies beyond cellulose fibers. It has been reported that certain ionic liquid/organic solvent mixtures dissolve cellulose. In this study, the tertiary phase diagram of microcrystalline cellulose, 1-Ethyl-3-methylimidazolium acetate (EMIMAc), and dimethylformamide (DMF) mixtures has been determined using optical cloud point method and small angle neutron scattering (SANS). Data indicate that a molar ratio of EMIMAc to cellulose repeating unit equal or greater than 3 is necessary but not sufficient in forming one-phase homogeneous solutions. A miscibility gap exists in the dilute regime, where a minimum of 5 mol% of EMIM Ac in DMF is needed to form homogenous solutions. SANS show that cellulose chains adopt Gaussian-like conformation in homogenous solutions. The solutions exhibit the characteristics of upper critical solution temperature. Clustering of cellulose chains occurs at low EMIMAc/DMF or EMIMAc/cellulose ratio, or at low temperatures. The mechanism of cellulose dissolution in tertiary mixture is discussed.

  9. Organic solvent soluble oxide supported hydrogenation catalyst precursors

    DOEpatents

    Edlund, David J.; Finke, Richard G.; Saxton, Robert J.

    1992-01-01

    The present invention discloses two polyoxoanion supported metal complexes found to be useful in olefin hydrogenation. The complexes are novel compositions of matter which are soluble in organic solvents. In particular, the compositions of matter comprise A.sub.x [L.sub.n Ir.sup.(I) .multidot.X.sub.2 M.sub.15 M'.sub.3 O.sub.62 ].sup.x- and A.sub.y [L.sub.n Ir.sup.(I) .multidot.X.sub.2 M.sub.9 M'.sub.3 O.sub.40 ].sup.y- where L is a ligand preferably chosen from 1,5-cyclooctadiene (COD), ethylene, cyclooctene, norbornadiene and other olefinic ligands; n=1 or 2 depending upon the number of double bonds present in the ligand L; X is a "hetero" atom chosen from B, Si, Ge, P, As, Se, Te, I, Co, Mn and Cu; M is either W or Mo; M' is preferably Nb or V but Ti, Zr, Ta, Hf are also useful; and A is a countercation preferably selected from tetrabutyl ammonium and alkali metal ions.

  10. Effect of Buffer Conditions and Organic Cosolvents on the Rate of Strain-Promoted Azide-Alkyne Cycloaddition.

    PubMed

    Davis, Derek L; Price, Erin K; Aderibigbe, Sabrina O; Larkin, Maureen X-H; Barlow, Emmett D; Chen, Renjie; Ford, Lincoln C; Gray, Zackery T; Gren, Stephen H; Jin, Yuwei; Keddington, Keith S; Kent, Alexandra D; Kim, Dasom; Lewis, Ashley; Marrouche, Rami S; O'Dair, Mark K; Powell, Daniel R; Scadden, Mick'l H C; Session, Curtis B; Tao, Jifei; Trieu, Janelle; Whiteford, Kristen N; Yuan, Zheng; Yun, Goyeun; Zhu, Judy; Heemstra, Jennifer M

    2016-08-01

    We investigate the effect of buffer identity, ionic strength, pH, and organic cosolvents on the rate of strain-promoted azide-alkyne cycloaddition with the widely used DIBAC cyclooctyne. The rate of reaction between DIBAC and a hydrophilic azide is highly tolerant to changes in buffer conditions but is impacted by organic cosolvents. Thus, bioconjugation reactions using DIBAC can be carried out in the buffer that is most compatible with the biomolecules being labeled, but the use of organic cosolvents should be carefully considered.

  11. Membrane separation in green chemical processing: solvent nanofiltration in liquid phase organic synthesis reactions.

    PubMed

    Livingston, Andrew; Peeva, Ludmila; Han, Shejiao; Nair, Dinesh; Luthra, Satinder Singh; White, Lloyd S; Freitas Dos Santos, Luisa M

    2003-03-01

    This paper describes ideas together with preliminary experimental results for applying solvent nanofiltration to liquid phase organic synthesis reactions. Membranes for organic solvent nanofiltration have only recently (during the 1990s) become available and, to date, have been applied primarily to food processing (vegetable oil processing, in particular) and refinery processes. Applications to organic synthesis, even at a laboratory feasibility level, are few. However, these membranes have great potential to improve the environmental performance of many liquid phase synthesis reactions by reducing the need for complex solvent handling operations. Examples that are shown to be feasible are solvent exchanges, where it is desired to swap a high molecular weight molecule from one solvent to another between separate stages in a complex synthesis, and recycle and reuse of homogeneous catalysts. In solvent exchanges, nanofiltration is shown to provide a fast and effective means of swapping from a high boiling point solvent to a solvent with a lower boiling point-this is a difficult operation by means of distillation. Solvent nanofiltration is shown to be able to separate two distinct types of homogeneous catalysts, phase transfer catalysts and organometallic catalysts, from their respective reaction products. In both cases the application of organic solvent nanofiltration allows several reuses of the same catalyst. Catalyst stability is shown to be an essential requirement for this technique to be effective. Finally, we present a discussion of scale-up aspects including membrane flux and process economics.

  12. Immobilization of Lipase by Adsorption Onto Magnetic Nanoparticles in Organic Solvents.

    PubMed

    Shi, Ying; Liu, Wei; Tao, Qing-Lan; Jiang, Xiao-Ping; Liu, Cai-Hong; Zeng, Sha; Zhang, Ye-Wang

    2016-01-01

    In order to improve the performance of lipase in organic solvents, a simple immobilization method was developed by adsorption of lipase onto Fe₃O₄@ SiO₂magnetic nanoparticles in organic solvent. Among the solvents tested, toluene was found to be the most effective solvent for the immobilization. A maximum immobilization yield of 97% and relative activity of 124% were achieved in toluene at 30 °C. The optimal temperature, enzyme loading and water activity were 30 °C, 1.25 mg/mg support and 0.48 aw, respectively. The residual activity of immobilized lipase was 67% after 10 cycles of use. The advantages of the immobilized lipase including easy recovery, high stability, and enhanced activity of immobilized lipase in organic solvents show potential industrial applications in anhydrous solvents. PMID:27398494

  13. FT-IR spectroscopy and DFT calculation study on the solvent effects of benzaldehyde in organic solvents.

    PubMed

    Li, Yi; Zhang, Hui; Liu, Qing

    2012-02-01

    FT-IR spectra of benzaldehyde in 11 different organic solvents were recorded and analyzed. The density functional theory (DFT) B3LYP/6-31G* method was chosen to calculate the infrared spectrum of benzaldehyde in gaseous state. The electrostatic effects of different solvents in benzaldehyde solutions were calculated using DFT with the self-consistent isodensity polarizable continuum model (SCI-PCM). Two remarkable carbonyl (C=O) peaks of benzaldehyde were observed by FT-IR in alcohol solvents, which were caused by different hydrogen bond species and explained by ab initio calculation. The results showed that the combination of SCI-PCM model and ab initio calculation could give excellent agreements with FT-IR spectra of title compound in solutions.

  14. The Buffering Balance: Modeling Arctic river total-, inorganic-, and organic-alkalinity fluxes

    NASA Astrophysics Data System (ADS)

    Hunt, C. W.; Salisbury, J.; Wollheim, W. M.; Mineau, M.; Stewart, R. J.

    2014-12-01

    River-borne inputs of alkalinity influence the pH and pCO2 of coastal ocean waters, and changes in alkalinity inputs also have implications for responses to climate-driven ocean acidification. Recent work has shown that alkalinity fluxes from rivers are not always dominated by inorganic carbon species, and can instead be composed somewhat or mostly of non-carbonate, presumably organic species. Concentrations and proportions of organic alkalinity (O-Alk) are correlated to dissolved organic carbon (DOC) concentrations and fluxes, which are predicted to rise as Arctic permafrost thaws and the hydrologic cycle intensifies. We have scaled results from watershed studies to develop a process-based model to simulate and aggregate Arctic river exports of total alkalinity, DOC, and O-Alk to the coastal sea. Total alkalinity, DOC, and O-Alk were loaded to a river network and routed through a 6-minute hydrologic model (FrAMES). We present results contrasting poorly buffered (e.g. the Kolyma river) and highly buffered (e.g. the Yukon river) systems, the impact of O-Alk on river pH and pCO2, and examine the seasonalities of inorganic and organic influences on coastal ocean carbonate chemistry.

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

    EPA Science Inventory

    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...

  16. Exposure Characteristics of Construction Painters to Organic Solvents

    PubMed Central

    Park, Hyunhee; Park, Hae Dong; Jang, Jae-Kil

    2015-01-01

    Background Construction painters have not been studied well in terms of their hazards exposure. The objective of this study was to evaluate the exposure levels of total volatile organic compounds (TVOCs) for painters in the construction industry. Methods Activity-specific personal air samplings were carried out in three waterproofing activities [polyurethane (PU), asphalt, and cement mortar] and three painting activities (epoxy, oil based, and water based) by using organic-vapor-monitor passive-sampling devices. Gas chromatograph with flame ionization detector could be used for identifying and quantifying individual organic chemicals. The levels of TVOCs, by summing up 15 targeted substances, were expressed in exposure-index (EI) values. Results As arithmetic means in the order of concentration levels, the EIs of TVOCs in waterproofing works were 10.77, 2.42, 1.78, 1.68, 0.47, 0.07, and none detected (ND) for indoor PU-primer task, outdoor PU-primer task, outdoor PU-resin task, indoor PU-resin task, asphalt-primer task, asphalt-adhesive task, and cement-mortar task, respectively. The highest EI for painting works was 5.61 for indoor epoxy-primer task, followed by indoor epoxy-resin task (2.03), outdoor oil-based-spray-paint task (1.65), outdoor water-based-paint task (0.66), and indoor oil-based-paint task (0.15). Assuming that the operations were carried out continuously for 8 hours without breaks and by using the arithmetic means of EIs for each of the 12 tasks in this study, 58.3% (7 out of 12) exceeded the exposure limit of 100% (EI > 1.0), while 8.3% (1 out of 12) was in 50–100% of exposure limit (0.5 > EI > 1.0), and 4 tasks out of 12 were located in less than 50% of the limit range (EI < 0.5). 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

  17. High-Pressure Solvent Vapor Annealing with a Benign Solvent To Rapidly Enhance the Performance of Organic Photovoltaics.

    PubMed

    Jung, Buyoung; Kim, Kangmin; Eom, Yoomin; Kim, Woochul

    2015-06-24

    A high-pressure solvent vapor annealing (HPSVA) treatment is suggested as an annealing process to rapidly achieve high-performance organic photovoltaics (OPVs); this process can be compatible with roll-to-roll processing methods and uses a benign solvent: acetone. Solvent vapor annealing can produce an advantageous vertical distribution in the active layer; however, conventional solvent vapor annealing is also time-consuming. To shorten the annealing time, high-pressure solvent vapor is exposed on the active layer of OPVs. Acetone is a nonsolvent for poly(3-hexylthiophene-2,5-diyl) (P3HT), but it can dissolve small amounts of 1-(3-methoxycarbonyl)-propyl-1,1-phenyl-(6,6)C61 (PCBM). Acetone vapor molecules can penetrate into the active layer under high vapor pressure conditions to alter the morphology. HPSVA induces a PCBM-rich phase near the cathode and facilitates the transport of free charge carriers to the electrode. Although P3HT is not soluble in acetone, locally rearranged P3HT crystallites are generated. The performance of OPV films was enhanced after HPSVA; the film treated at 30 kPa for 10 s showed optimum performance. Additionally, this HPSVA method could be adapted for mass production because the temporary exposure of films to high-pressure acetone vapor in ambient conditions also improved performance.

  18. Performance of organic photovoltaics using an ytterbium trifluoride n-type buffer layer

    NASA Astrophysics Data System (ADS)

    Ji, Chan Hyuk; Jang, Ji Min; Oh, Se Young

    2016-03-01

    Ytterbium trifluoride (YbF3) was used as an n-type cathode buffer layer in conventional poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester (P3HT:PC60BM) bulk heterojunction (BHJ) organic photovoltaic cells. This buffer layer acts as an electron-transport layer and improves the open circuit voltage ( V oc), power conversion efficiency (PCE), and interfacial durability of the device. The physical properties and performance of the device were studied using impedance spectroscopy, photocurrent measurements, ultraviolet photoelectron spectroscopy, and atomic force microscopy. The PCE reached to 3.2% with a 65% fill factor under 1 sun irradiation. The PCE decreased to half of its original value after 120 h at room temperature in air or 24 h at 70°C in air. Comparison with Yb and TiOx cathode buffer layers reveals that YbF3 has superior performance and longevity. These findings suggest that YbF3 has the potential to replace costly device encapsulation. [Figure not available: see fulltext.

  19. Effect of organic solvents on the conformation and interaction of catalase and anticatalase antibodies.

    PubMed

    Rehan, Mohd; Younus, Hina

    2006-05-30

    Effect of six organic solvents-methanol, ethanol, propanol, dimethyl sulphoxide (DMSO), N,N-dimethyl formamide (DMF), and glycerol on the conformation and interaction of catalase and anticatalase antibodies were studied with the aim of identifying the solvents in which antigen-antibody interactions are strong. The antigen binding activity of the antibodies in the various organic solvents increased in the following order: ethanolorganic solventorganic solvents used in this study. Catalase activity was inhibited in DMSO. However, the enzyme was activated in DMF upto about 50% of its concentration. PMID:16677702

  20. Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

    SciTech Connect

    Starr, J.N.; King, C.J.

    1991-11-01

    The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.

  1. Fetotoxic effects of exposure to the vapor of organic solvents from a synthetic adhesive in mice

    SciTech Connect

    Tachi, N.; Shimotori, S.; Naruse, N.; Itani, T.; Aoyama, M. ); Fujise, H.; Sonoki, S. )

    1994-09-01

    Synthetic adhesives are widely used in various industries as well as at home. Adhesives usually contain several organic solvents which easily vaporize. Exposure can cause aplastic anemia and polyneuropathy in adults. Chronic glue sniffing results in aplastic anemia, polyneuropathy, and muscular atrophy. Inhalation of the solvent contained in adhesives, such as n-hexane, toluene, xylene, and benzene by pregnant animals can decrease the number of live fetuses and retard fetal growth. In humans, the risk of spontaneous abortion is increased in workers exposed to organic solvents. However, information is still limited about the effects of exposure to organic solvents vaporized from adhesives on fetuses. In the present study, female mice were exposed throughout pregnancy to organic solvents vaporized from an adhesive to clarify the effects of the inhalation on progeny. 19 refs., 1 fig., 4 tabs.

  2. Ultraviolet-ozone-treated PEDOT:PSS as anode buffer layer for organic solar cells.

    PubMed

    Su, Zisheng; Wang, Lidan; Li, Yantao; Zhao, Haifeng; Chu, Bei; Li, Wenlian

    2012-08-17

    Ultraviolet-ozone-treated poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)was used as the anode buffer layer in copper phthalocyanine (CuPc)/fullerene-based solar cells. The power conversion efficiency of the cells with appropriated UV-ozone treatment was found to increase about 20% compared to the reference cell. The improved performance is attributed to the increased work function of the PEDOT:PSS layer, which improves the contact condition between PEDOT:PSS and CuPc, hence increasing the extraction efficiency of the photogenerated holes and decreasing the recombination probability of holes and electrons in the active organic layers.

  3. Solute-solvent interactions in micellar electrokinetic chromatography. Selectivity of lithium dodecyl sulfate-lithium perfluorooctanesulfonate mixed-micellar buffers.

    PubMed

    Fuguet, E; Ràfols, C; Bosch, E; Rosés, M; Abraham, M H

    2001-01-12

    The solvation parameter model has been applied to the characterization of micellar electrokinetic chromatographic (MEKC) systems with mixtures of lithium dodecyl sulfate and lithium perfluorooctanesulfonate as surfactant. The variation in MEKC surfactant composition results in changes in the coefficients of the correlation equation, which in turns leads to information on solute-solvent and solute-micelle interactions. Lithium perfluorooctanesulfonate is more dipolar and hydrogen bond acidic but less polarizable and hydrogen bond basic than lithium dodecyl sulfate. Therefore mixtures of lithium dodecyl sulfate and lithium perfluorooctanesulfonate cover a very wide range of polarity and hydrogen bond properties, which in turn results in important selectivity changes for analytes with different solute properties.

  4. Effects of organic solvents on the barrier properties of human nail.

    PubMed

    Smith, Kelly A; Hao, Jinsong; Li, S Kevin

    2011-10-01

    The effects of organic solvent systems on nail hydration and permeability have not been well studied. The objectives of the present study were to investigate the effects of binary aqueous organic solvent systems of ethanol (EtOH), propylene glycol (PPG), and polyethylene glycol 400 (PEG) on the barrier properties of nail plates. (3) H-water, (14) C-urea, and (14) C-tetraethylammonium ions were the probes in the nail uptake and transport experiments to study the effect(s) of organic solvents on nail hydration and permeability. Gravimetric studies were also performed as a secondary method to study nail hydration and the reversibility of the nail after organic solvent treatments. Both ungual uptake and transport were directly related to the concentration of the organic solvent in the binary systems. Partitioning of the probes into and transport across the nail decreased with an increase in the organic solvent concentration. These changes corresponded to the changes in solution viscosity and the barrier properties of the nail. In general, the effects for PPG and PEG were more pronounced than those for EtOH. Practically, these results suggest that organic solvents in formulations can increase nail barrier resistivity. PMID:21607952

  5. Effects of organic solvents on the barrier properties of human nail.

    PubMed

    Smith, Kelly A; Hao, Jinsong; Li, S Kevin

    2011-10-01

    The effects of organic solvent systems on nail hydration and permeability have not been well studied. The objectives of the present study were to investigate the effects of binary aqueous organic solvent systems of ethanol (EtOH), propylene glycol (PPG), and polyethylene glycol 400 (PEG) on the barrier properties of nail plates. (3) H-water, (14) C-urea, and (14) C-tetraethylammonium ions were the probes in the nail uptake and transport experiments to study the effect(s) of organic solvents on nail hydration and permeability. Gravimetric studies were also performed as a secondary method to study nail hydration and the reversibility of the nail after organic solvent treatments. Both ungual uptake and transport were directly related to the concentration of the organic solvent in the binary systems. Partitioning of the probes into and transport across the nail decreased with an increase in the organic solvent concentration. These changes corresponded to the changes in solution viscosity and the barrier properties of the nail. In general, the effects for PPG and PEG were more pronounced than those for EtOH. Practically, these results suggest that organic solvents in formulations can increase nail barrier resistivity.

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

    PubMed Central

    Ahmed, Sofia; Mustaan, Nafeesa; Sheraz, Muhammad Ali; Nabi, Syeda Ayesha Ahmed un; Ahmad, Iqbal

    2015-01-01

    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. PMID:26783497

  7. Improvement of organic solvent tolerance by disruption of the lon gene in Escherichia coli.

    PubMed

    Watanabe, Rei; Doukyu, Noriyuki

    2014-08-01

    The Lon ATP-dependent protease plays an important role in regulating many biological processes in bacteria. In this study, we examined the organic solvent tolerance of a Δlon mutant of Escherichia coli K-12 and found that the mutant showed remarkably higher organic solvent tolerance than the parent strain. Δlon mutants are known to overproduce capsular polysaccharide, resulting in the formation of mucoid colonies. We considered that this increase in capsular polysaccharide production might be involved in the organic solvent tolerance in E. coli. However, a ΔlonΔwcaJ double-gene mutant displaying a nonmucoid phenotype was as tolerant to organic solvents as the Δlon mutant, suggesting that capsular polysaccharide is not involved in organic solvent tolerance. On the other hand, the Lon protease is known to exhibit proteolytic activity against the transcriptional activators MarA and SoxS, which can enhance the expression level of the AcrAB-TolC efflux pump. We found that the Δlon mutant showed a higher expression level of AcrB than the parent strain. In addition, the ΔlonΔacrB double-gene mutant showed a significant decrease in organic solvent tolerance. Thus, it was shown that organic solvent tolerance in the Δlon mutant depends on the AcrAB-TolC pump but not capsular polysaccharide. E. coli strain JA300 acrRIS marR overexpresses the AcrAB-TolC pump and exhibits high-level solvent tolerance. In an attempt to further improve the solvent tolerance of JA300 acrRIS marR, a lon gene disruptant of this strain was constructed. However, the resulting mutant JA300 acrRIS marR Δlon showed lower solvent tolerance than JA300 acrRIS marR.

  8. Degradation problems with the solvent extraction organic at Roessing uranium

    SciTech Connect

    Munyungano, Brodrick; Feather, Angus; Virnig, Michael

    2008-07-01

    Roessing Uranium Ltd recovers uranium from a low-grade ore in Namibia. Uranium is recovered and purified from an ion-exchange eluate in a solvent-extraction plant. The solvent-extraction plant uses Alamine 336 as the extractant for uranium, with isodecanol used as a phase modifier in Sasol SSX 210, an aliphatic hydrocarbon diluent. Since the plant started in the mid 1970's, there have been a few episodes where the tertiary amine has been quickly and severely degraded when the plant was operated outside certain operating parameters. The Rossing experience is discussed in more detail in this paper. (authors)

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

    SciTech Connect

    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.

  10. Influence of organic buffers on bacteriocin production by Streptococcus thermophilus ST110.

    PubMed

    Somkuti, George A; Gilbreth, Stefanie E

    2007-08-01

    The effect of the organic buffer salts MES, MOPS, and PIPES on the growth of S. thermophilus ST110, medium pH, and accumulation of the antipediococcal bacteriocin thermophilin 110 were evaluated in whey permeate media over a period of 24 h. In nonbuffered medium, thermophilin 110 production at 37 degrees C paralleled the growth of S. thermophilus ST110 and reached a maximum after 8-10 h. Addition of organic buffer salts decreased the drop in medium pH and resulted in increased biomass (dry cells; microg/mL) and higher yields of thermophilin 110 (units/microg cells). The best results were obtained by the addition of 1% (w/v) MES to the medium, which reduced the pH drop to 1.8 units after 10 h of growth (compared to 2.3 pH units in the control) and resulted in a 1.5-fold increase in cell mass (495 microg/mL) and a 7-fold increase in thermophilin 110 yield (77 units/microg dry cells) over the control. The results showed that whey permeate-based media may be suitable for producing large amounts of thermophilin 110 needed for controlling spoilage pediococci in industrial wine and beer fermentations.

  11. Structure, Optical Absorption, and Performance of Organic Solar Cells Improved by Gold Nanoparticles in Buffer Layers.

    PubMed

    Yang, Yingguo; Feng, Shanglei; Li, Meng; Wu, Zhongwei; Fang, Xiao; Wang, Fei; Geng, Dongping; Yang, Tieying; Li, Xiaolong; Sun, Baoquan; Gao, Xingyu

    2015-11-11

    11-Mercaptoundecanoic acid (MUA)-stabilized gold nanoparticles (AuNPs) embedded in copper phthalocyanine (CuPc) were used as a buffer layer between a poly(3-hexyl-thiophene) (P3HT)/[6,6]-phenyl C61-butyric acid methyl ester (PCBM) bulk heterojunction and anodic indium-tin oxide (ITO) substrate. As systematic synchrotron-based grazing incidence X-ray diffraction (GIXRD) experiments demonstrated that the AuNPs present in the buffer layer can improve the microstructure of the active layer with a better lamella packing of P3HT from the surface to the interior, UV-visible absorption spectrum measurements revealed enhanced optical absorption due to the localized surface plasma resonance (LSPR) generated by the AuNPs. The device of ITO/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate/CuPc:MUA-stabilized AuNPs/P3HT:PCBM/LiF/Al was found with over 24% enhancement of power conversion efficiency (PCE) in comparison with reference devices without AuNPs. This remarkable improvement in PCE should be partially attributed to LSPR generated by the AuNPs and partially to improved crystallization as well as preferred orientation order of P3HT due to the presence of the AuNPs, which would promote more applications of metal NPs in the organic photovoltaic devices and other organic multilayer devices. PMID:26477556

  12. Lipase in aqueous-polar organic solvents: Activity, structure, and stability

    PubMed Central

    Kamal, Md Zahid; Yedavalli, Poornima; Deshmukh, Mandar V; Rao, Nalam Madhusudhana

    2013-01-01

    Studying alterations in biophysical and biochemical behavior of enzymes in the presence of organic solvents and the underlying cause(s) has important implications in biotechnology. We investigated the effects of aqueous solutions of polar organic solvents on ester hydrolytic activity, structure and stability of a lipase. Relative activity of the lipase monotonically decreased with increasing concentration of acetone, acetonitrile, and DMF but increased at lower concentrations (upto ∼20% v/v) of dimethylsulfoxide, isopropanol, and methanol. None of the organic solvents caused any appreciable structural change as evident from circular dichorism and NMR studies, thus do not support any significant role of enzyme denaturation in activity change. Change in 2D [15N, 1H]-HSQC chemical shifts suggested that all the organic solvents preferentially localize to a hydrophobic patch in the active-site vicinity and no chemical shift perturbation was observed for residues present in protein's core. This suggests that activity alteration might be directly linked to change in active site environment only. All organic solvents decreased the apparent binding of substrate to the enzyme (increased Km); however significantly enhanced the kcat. Melting temperature (Tm) of lipase, measured by circular dichroism and differential scanning calorimetry, altered in all solvents, albeit to a variable extent. Interestingly, although the effect of all organic solvents on various properties on lipase is qualitatively similar, our study suggest that magnitudes of effects do not appear to follow bulk solvent properties like polarity and the solvent effects are apparently dictated by specific and local interactions of solvent molecule(s) with the protein. PMID:23625694

  13. WASTE TREATABILITY TESTS OF SPENT SOLVENT AND OTHER ORGANIC WASTEWATERS

    EPA Science Inventory

    Some commercial and industrial facilities treat RCRA spent solvent wastewaters by steam stripping, carbon adsorption, and/or biological processes. Thirteen facilities were visited by EPA's Office of Research and Development (ORD) from June 1985 to September 1986, to conduct sampl...

  14. EXPEDITIOUS SOLVENT-FREE ORGANIC SYNTHESES USING MICROWAVE IRRADIATION

    EPA Science Inventory

    Microwave-expedited solvent-free synthetic processes involve the exposure of neat reactants to microwave (MW) irradiation in the presence of supported reagents or catalysts on mineral oxides. Recent developments are described and the salient features of these high yield protocol...

  15. Boost Up Carrier Mobility for Ferroelectric Organic Transistor Memory via Buffering Interfacial Polarization Fluctuation

    PubMed Central

    Sun, Huabin; Wang, Qijing; Li, Yun; Lin, Yen-Fu; Wang, Yu; Yin, Yao; Xu, Yong; Liu, Chuan; Tsukagoshi, Kazuhito; Pan, Lijia; Wang, Xizhang; Hu, Zheng; Shi, Yi

    2014-01-01

    Ferroelectric organic field-effect transistors (Fe-OFETs) have been attractive for a variety of non-volatile memory device applications. One of the critical issues of Fe-OFETs is the improvement of carrier mobility in semiconducting channels. In this article, we propose a novel interfacial buffering method that inserts an ultrathin poly(methyl methacrylate) (PMMA) between ferroelectric polymer and organic semiconductor layers. A high field-effect mobility (μFET) up to 4.6 cm2 V−1 s−1 is obtained. Subsequently, the programming process in our Fe-OFETs is mainly dominated by the switching between two ferroelectric polarizations rather than by the mobility-determined charge accumulation at the channel. Thus, the “reading” and “programming” speeds are significantly improved. Investigations show that the polarization fluctuation at semiconductor/insulator interfaces, which affect the charge transport in conducting channels, can be suppressed effectively using our method. PMID:25428665

  16. Boost Up Carrier Mobility for Ferroelectric Organic Transistor Memory via Buffering Interfacial Polarization Fluctuation

    NASA Astrophysics Data System (ADS)

    Sun, Huabin; Wang, Qijing; Li, Yun; Lin, Yen-Fu; Wang, Yu; Yin, Yao; Xu, Yong; Liu, Chuan; Tsukagoshi, Kazuhito; Pan, Lijia; Wang, Xizhang; Hu, Zheng; Shi, Yi

    2014-11-01

    Ferroelectric organic field-effect transistors (Fe-OFETs) have been attractive for a variety of non-volatile memory device applications. One of the critical issues of Fe-OFETs is the improvement of carrier mobility in semiconducting channels. In this article, we propose a novel interfacial buffering method that inserts an ultrathin poly(methyl methacrylate) (PMMA) between ferroelectric polymer and organic semiconductor layers. A high field-effect mobility (μFET) up to 4.6 cm2 V-1 s-1 is obtained. Subsequently, the programming process in our Fe-OFETs is mainly dominated by the switching between two ferroelectric polarizations rather than by the mobility-determined charge accumulation at the channel. Thus, the ``reading'' and ``programming'' speeds are significantly improved. Investigations show that the polarization fluctuation at semiconductor/insulator interfaces, which affect the charge transport in conducting channels, can be suppressed effectively using our method.

  17. Solubility of hydrophobic organic pollutants in binary and multicomponent aqueous solvents.

    PubMed

    Ruckenstein, E; Shulgin, I

    2005-03-15

    The present paper deals with the application of fluctuation theory of solutions to the solubility of poorly soluble substances of environmental significance in aqueous mixed solvents. The fluctuation theory of ternary solutions was first used to derive an expression for the activity coefficient of a solute at infinite dilution in a binary mixed solvent. This equation contains the activity coefficients of the constituents of the solute-free mixed solvent and the molar volume of the solute-free mixed solvent. Further, the derived expression for the activity coefficient of a solute at infinite dilution was used to generate a number of expressions for the solubility of solids in aqueous mixed solvents. Several expressions for the activity coefficients of the components were considered: first, the mixed solvent was considered an ideal mixture; second, the activity coefficients of the constituents of the binary solvent were expressed using the two-suffix Margules equations; third, the activity coefficients of the constituents of the binary solvent were expressed using the Wilson equations. The obtained expressions were applied to 25 experimental data sets pertaining to the solubilities of hydrophobic organic pollutants (HOP) in aqueous mixed solvents. It was found that the suggested equations can be used for an accurate and reliable correlation of the solubilities in aqueous mixed binary solvents. The best results were obtained by combining our expression for the activity coefficient of a solute at infinite dilution in a mixed solvent with the Wilson equations for the activity coefficients of the constituents of a solute-free mixed solvent. The derived equations can also be used for predicting the solubilities of poorly soluble environmentally important compounds in aqueous mixed solvents using for the Wilson parameters those obtained from vapor-liquid equilibrium data. A similar methodology was applied to the solubility of poorly soluble substances of environmental

  18. Organic solvent adaptation of Gram positive bacteria: applications and biotechnological potentials.

    PubMed

    Torres, Sebastian; Pandey, Ashok; Castro, Guillermo R

    2011-01-01

    Organic-solvent-tolerant bacteria are considered extremophiles with different tolerance levels that change among species and strains, but also depend on the inherent toxicity of the solvent. Extensive studies to understand the mechanisms of organic solvent tolerance have been done in Gram-negative bacteria. On the contrary, the information on the solvent tolerance mechanisms in Gram-positive bacteria remains scarce. Possible shared mechanisms among Gram-(-) and Gram-(+) microorganisms include: energy-dependent active efflux pumps that export toxic organic solvents to the external medium; cis-to-trans isomerization of unsaturated membrane fatty acids and modifications in the membrane phospholipid headgroups; formation of vesicles loaded with toxic compounds; and changes in the biosynthesis rate of phospholipids to accelerate repair processes. However, additional physiological responses of Gram-(+) bacteria to organic solvents seem to be specific. The aim of the present work is to review the state of the art of responsible mechanisms for organic solvent tolerance in Gram-positive bacteria, and their industrial and environmental biotechnology potential. PMID:21504787

  19. The solubility of hydrophobic aromatic chemicals in organic solvent/water mixtures

    SciTech Connect

    Dickhut, R.M.

    1989-01-01

    The influence of dissolved organic solvents on the aqueous phase solubility of hydrophobic aromatic chemicals was investigated. To provide a basis for a comprehensive evaluation of the importance of cosolvent properties on solubility, the effects of several different organic cosolvents on the solubility of a model hydrophobic solute, naphthalene, were determined. Naphthalene solubility was measured in binary, ternary, and quaternary alcohol/water (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol) mixtures, binary ketone/water (acetone, methylethylketone, diethylketone), and aromatic organic solvent/water (benzene, toluene) mixtures. The solubility data were statistically evaluated and used to obtain an estimate of the overall accuracy of solubility measurements of hydrophobic chemicals in organic solvent/water mixtures. An accurate data base for mixed solvent solubility was established by combining the solubility data with additional solubility data obtained experimentally and from the literature. Thermodynamic models for predicting solubility in organic solvent/water mixtures were tested against the experimental data. The effects of organic cosolvent properties and solute hydrophobicity on solubility behavior and model predictive capability were evaluated. The results were used to evaluate the accuracy of existing models for predicting solubility and to explore possible molecular interactions in organic solvent/water mixtures.

  20. 40 CFR Table 6 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Petroleum Solvent Groups a 6 Table 6 to Subpart QQQQ of Part 63 Protection of Environment ENVIRONMENTAL...—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in... Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. c...

  1. 40 CFR Table 4 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups 1

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Petroleum Solvent Groups 1 4 Table 4 to Subpart RRRR of Part 63 Protection of Environment ENVIRONMENTAL... Organic HAP Mass Fraction for Petroleum Solvent Groups 1 You May Use the Mass Fraction Values in the..., Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend. 3 E.g.,...

  2. PERTURBATION OF VOLTAGE-SENSITIVE CALCIUM FUNCTION IN PHEOCHROMOCYTOMA CELLS BY VOLATILE ORGANIC SOLVENTS.

    EPA Science Inventory

    Volatile organic solvents such as toluene (TOL) and trichloroethylene perturb nervous system function and share characteristic effects with other central nervous system depressants such as anesthetic gasses, ethanol, benzodiazepines and barbiturates. Recently, mechanistic studies...

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

    EPA Science Inventory

    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...

  4. Utilization of Metal Oxides and Chalcogenides Stabilized in Organic Solvents

    NASA Astrophysics Data System (ADS)

    Lampert, Lester; Flaig, Robby; Camacho, Jorge; Hamilton, James

    2011-03-01

    Metal oxides and metal chalcogenides are important materials for a variety of applications including photocatalysis for decomposition of water, conductive and optical coatings, catalysts, photovoltaics, pryoelectrics, self-cleaning surfaces, pigments, and high efficiency Li-insertion materials in batteries among many other applications. Fundamental discoveries of surprising solubility of insoluble materials such as single and multi-walled carbon nanotubes and graphene has lead us to discover that certain metal oxides and metal chalcogenides such as TiO2 are soluble in certain solvents. Due to the industrial importance of TiO2, discovering stable pure solvent systems demonstrates a possibility to avoid surface modification of TiO2 nanoparticles by use materials such as of (3-methacryloxypropyl)-trimethoxysilane and various other methods of artificial stabilization. We have created thin films of TiO2, transparent ultraviolet (UV) --absorptive polymers, and Li-ion battery anodes with graphene-TiO2 hybrid materials.

  5. Cellulose solvent- and organic solvent-based lignocellulose fractionation enabled efficient sugar release from a variety of lignocellulosic feedstocks.

    PubMed

    Sathitsuksanoh, Noppadon; Zhu, Zhiguang; Zhang, Y-H Percival

    2012-08-01

    Developing feedstock-independent biomass pretreatment would be vital to second generation biorefineries that would fully utilize diverse non-food lignocellulosic biomass resources, decrease transportation costs of low energy density feedstock, and conserve natural biodiversity. Cellulose solvent- and organic solvent-based lignocellulose fractionation (COSLIF) was applied to a variety of feedstocks, including Miscanthus, poplar, their mixture, bagasse, wheat straw, and rice straw. Although non-pretreated biomass samples exhibited a large variation in enzymatic digestibility, the COSLIF-pretreated biomass samples exhibited similar high enzymatic glucan digestibilities and fast hydrolysis rates. Glucan digestibilities of most pretreated feedstocks were ∼93% at five filter paper units per gram of glucan. The overall glucose and xylose yields for the Miscanthus:poplar mixture at a weight ratio of 1:2 were 93% and 85%, respectively. These results suggested that COSLIF could be regarded as a feedstock-independent pretreatment suitable for processing diverse feedstocks by adjusting pretreatment residence time only. PMID:22613899

  6. Recurrent Acute Liver Failure Because of Acute Hepatitis Induced by Organic Solvents: A Case Report.

    PubMed

    Ito, Daisuke; Tanaka, Tomohiro; Akamatsu, Nobuhisa; Ito, Kyoji; Hasegawa, Kiyoshi; Sakamoto, Yoshihiro; Nakagawa, Hayato; Fujinaga, Hidetaka; Kokudo, Norihiro

    2016-01-01

    The authors present a case of recurrent acute liver failure because of occupational exposure to organic solvents. A 35-year-old man with a 3-week history of worsening jaundice and flu-like symptoms was admitted to our hospital. Viral hepatitis serology and autoimmune factors were negative. The authors considered liver transplantation, but the patient's liver function spontaneously recovered. Liver biopsy revealed massive infiltration of neutrophils, but the cause of the acute hepatitis was not identified. Four months after discharge, the patient's liver function worsened again. The authors considered the possibility of antinuclear antibody-negative autoimmune hepatitis and initiated steroid treatment, which was effective. Four months after discharge, the patient was admitted for repeated liver injury. The authors started him on steroid pulse therapy, but this time it was not effective. Just before the first admission, he had started his own construction company where he was highly exposed to organic solvents, and thus the authors considered organic solvent-induced hepatitis. Although urine test results for organic solvents were negative, a second liver biopsy revealed severe infiltration of neutrophils, compatible with toxic hepatitis. Again, his liver function spontaneously improved. Based on the pathology and detailed clinical course, including the patient's high exposure to organic solvents since just before the first admission, and the spontaneous recovery of his liver damage in the absence of the exposure, he was diagnosed with toxic hepatitis. The authors strongly advised him to avoid organic solvents. Since then, he has been in good health without recurrence. This is the first report of recurrent acute liver failure because of exposure to organic solvents, which was eventually diagnosed through a meticulous medical history and successfully recovered by avoiding the causative agents. In acute liver failure with an undetermined etiology, clinicians should rule

  7. Recurrent Acute Liver Failure Because of Acute Hepatitis Induced by Organic Solvents

    PubMed Central

    Ito, Daisuke; Tanaka, Tomohiro; Akamatsu, Nobuhisa; Ito, Kyoji; Hasegawa, Kiyoshi; Sakamoto, Yoshihiro; Nakagawa, Hayato; Fujinaga, Hidetaka; Kokudo, Norihiro

    2016-01-01

    Abstract The authors present a case of recurrent acute liver failure because of occupational exposure to organic solvents. A 35-year-old man with a 3-week history of worsening jaundice and flu-like symptoms was admitted to our hospital. Viral hepatitis serology and autoimmune factors were negative. The authors considered liver transplantation, but the patient's liver function spontaneously recovered. Liver biopsy revealed massive infiltration of neutrophils, but the cause of the acute hepatitis was not identified. Four months after discharge, the patient's liver function worsened again. The authors considered the possibility of antinuclear antibody-negative autoimmune hepatitis and initiated steroid treatment, which was effective. Four months after discharge, the patient was admitted for repeated liver injury. The authors started him on steroid pulse therapy, but this time it was not effective. Just before the first admission, he had started his own construction company where he was highly exposed to organic solvents, and thus the authors considered organic solvent-induced hepatitis. Although urine test results for organic solvents were negative, a second liver biopsy revealed severe infiltration of neutrophils, compatible with toxic hepatitis. Again, his liver function spontaneously improved. Based on the pathology and detailed clinical course, including the patient's high exposure to organic solvents since just before the first admission, and the spontaneous recovery of his liver damage in the absence of the exposure, he was diagnosed with toxic hepatitis. The authors strongly advised him to avoid organic solvents. Since then, he has been in good health without recurrence. This is the first report of recurrent acute liver failure because of exposure to organic solvents, which was eventually diagnosed through a meticulous medical history and successfully recovered by avoiding the causative agents. In acute liver failure with an undetermined etiology, clinicians

  8. Enhanced production and organic solvent stability of a protease from Brevibacillus laterosporus strain PAP04.

    PubMed

    Anbu, P

    2016-01-01

    A bacterial strain (PAP04) isolated from cattle farm soil was shown to produce an extracellular, solvent-stable protease. Sequence analysis using 16S rRNA showed that this strain was highly homologous (99%) to Brevibacillus laterosporus. Growth conditions that optimize protease production in this strain were determined as maltose (carbon source), skim milk (nitrogen source), pH 7.0, 40°C temperature, and 48 h incubation. Overall, conditions were optimized to yield a 5.91-fold higher production of protease compared to standard conditions. Furthermore, the stability of the enzyme in organic solvents was assessed by incubation for 2 weeks in solutions containing 50% concentration of various organic solvents. The enzyme retained activity in all tested solvents except ethanol; however, the protease activity was stimulated in benzene (74%) followed by acetone (63%) and chloroform (54.8%). In addition, the plate assay and zymography results also confirmed the stability of the PAP04 protease in various organic solvents. The organic solvent stability of this protease at high (50%) concentrations of solvents makes it an alternative catalyst for peptide synthesis in non-aqueous media. PMID:27007657

  9. Phase behavior and self-organized structures of diglycerol monolaurate in different nonpolar organic solvents.

    PubMed

    Shrestha, Lok Kumar; Sato, Takaaki; Aramaki, Kenji

    2007-06-01

    Nonaqueous phase behavior and reverse micellar structures of diglycerol monolaurate (DGL) in different nonpolar organic solvents, such as n-decane, n-tetradecane, and n-hexadecane, have been studied over a wide range of compositions and temperatures. The equilibrium phases are identified by means of visual observation and small-angle X-ray scattering (SAXS). A solid phase present at lower temperature swells small amount of oils and transforms into a lamellar liquid crystalline structure at higher temperature. The melting temperature of the solid phase is virtually constant at all mixing ratios of the surfactant and oil. With the further increase of temperature, the liquid crystal transforms into an isotropic single-liquid phase near the surfactant axis, whereas there is a coexistence region of two isotropic phases near the solvent axis. The area of the two-liquid (II) phase region depends largely on the hydrocarbon chain length of the oils, the longer chain leading to the wider II area. Accordingly, the DGL surfactant is most miscible with decane, exhibiting a reduced miscibility with increasing solvent hydrocarbon chain length. Increasing temperature enhances the dissolution tendency of the surfactant in oil, where the two-liquid phase transforms into an isotropic single phase. SAXS analysis based on the GIFT technique is used to characterize the structure of the reverse micellar aggregates in the isotropic single-phase liquids. We have demonstrated that instead of changing polarity or a functional group of the solvent molecules, if we optimize the hydrophilic nature of the surfactant head group, the alkyl chain length of the solvent oils can serve as a tunable parameter of the micellar geometry. The hydrophilic surfactant DGL interestingly forms cylindrical micelles in nonpolar oils, decane, and tetradecane in the dilute region above the II phase region. The micellar size shows temperature dependence behavior, and the micellar length goes on increasing with

  10. Digitally-Enabled Organizational Routines at the Organization-Environment Boundary: Buffering and the Role of Technology

    ERIC Educational Resources Information Center

    Hillison, Derek William

    2009-01-01

    Boundary units of an organization uniquely experience the tension between adaptation to environmental variation and maintaining stable outcomes for the rest of the organization. In our world of just-in-time supply chain systems, lot-sizes of one, lean manufacturing and an increasing focus on services, traditional forms of buffering such as queuing…

  11. Passive dosing versus solvent spiking for controlling and maintaining hydrophobic organic compound exposure in the Microtox® assay.

    PubMed

    Smith, Kilian E C; Jeong, Yoonah; Kim, Jongwoon

    2015-11-01

    Microbial toxicity bioassays such as the Microtox® test are ubiquitously applied to measure the toxicity of chemicals and environmental samples. In many ways their operation is conducive to the testing of organic chemicals. They are of short duration, use glass cuvettes and take place at reduced temperatures in medium lacking sorbing components. All of these are expected to reduce sorptive and volatile losses, but particularly for hydrophobic organics the role of such losses in determining the bioassay response remains unclear. This study determined the response of the Microtox® test when using solvent spiking compared to passive dosing for introducing the model hydrophobic compounds acenaphthene, phenanthrene, fluoranthene and benzo(a)pyrene. Compared to solvent spiking, the apparent sensitivity of the Microtox® test with passive dosing was 3.4 and 12.4 times higher for acenaphthene and phenanthrene, respectively. Furthermore, fluoranthene only gave a consistent response with passive dosing. Benzo(a)pyrene did not result in a response with either spiking or passive dosing even at aqueous solubility. Such differences in the apparent sensitivity of the Microtox® test can be traced back to the precise definition of the dissolved exposure concentrations and the buffering of losses with passive dosing. This highlights the importance of exposure control even in simple and short-term microbial bioassays such as the Microtox® test. PMID:26117202

  12. 40 CFR Table 6 to Subpart Vvvv of... - Default Organic HAP Contents of Petroleum Solvent Groups

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Contents of... Boat 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...

  13. 40 CFR Table 6 to Subpart Vvvv of... - Default Organic HAP Contents of Petroleum Solvent Groups

    Code of Federal Regulations, 2010 CFR

    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...

  14. 40 CFR Table 6 to Subpart Vvvv of... - Default Organic HAP Contents of Petroleum Solvent Groups

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Contents of... Boat 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...

  15. Solubility, stability, and electrochemical studies of sulfur-sulfide solutions in organic solvents

    NASA Technical Reports Server (NTRS)

    Fielder, W. L.; Singer, J.

    1978-01-01

    A preliminary study of the sulfur electrode in organic solvents suggests that the system warrants further investigation for use in a low temperature (100 deg to 120 C) Na-S secondary battery. A qualitative screening was undertaken at 120 C to determine the solubilities and stabilities of Na2S and Na2S2 in representatives of many classes of organic solvents. From the screening and quantitative studies, two classes of solvents were selected for work; amides and cyclic polyalcohols. Voltammetric and Na-S cell charge discharge studies of sulfide solutions in organic solvents (e.g., N, N-dimethylformamide) at 120 C suggested that the reversibilities of the reactions on Pt or high density graphite were moderately poor. However, the sulfur electrode was indeed reducible (and oxidizable) through the range of elemental sulfur to Na2S. Reactions and mechanisms are proposed for the oxidation reduction processes occurring at the sulfur electrode.

  16. Probing Contaminant Transport to and from Clay Surfaces in Organic Solvents and Water Using Solution Calorimetry.

    PubMed

    Pourmohammadbagher, Amin; Shaw, John M

    2015-09-15

    Clays, in tailings, are a significant ongoing environmental concern in the mining and oilsands production industries, and clay rehabilitation following contamination poses challenges episodically. Understanding the fundamentals of clay behavior can lead to better environmental impact mitigation strategies. Systematic calorimetric measurements are shown to provide a framework for parsing the synergistic and antagonistic impacts of trace (i.e., parts per million level) components on the surface compositions of clays. The enthalpy of solution of as-received and "contaminated" clays, in as-received and "contaminated" organic solvents and water, at 60 °C and atmospheric pressure, provides important illustrative examples. Clay contamination included pre-saturation of clays with water and organic liquids. Solvent contamination included the addition of trace water to organic solvents and trace organic liquids to water. Enthalpy of solution outcomes are interpreted using a quantitative mass and energy balance modeling framework that isolates terms for solvent and trace contaminant sorption/desorption and surface energy effects. Underlying surface energies are shown to dominate the energetics of the solvent-clay interaction, and organic liquids as solvents or as trace contaminants are shown to displace water from as-received clay surfaces. This approach can be readily extended to include pH, salts, or other effects and is expected to provide mechanistic and quantitative insights underlying the stability of clays in tailings ponds and the behaviors of clays in diverse industrial and natural environments.

  17. Probing Contaminant Transport to and from Clay Surfaces in Organic Solvents and Water Using Solution Calorimetry.

    PubMed

    Pourmohammadbagher, Amin; Shaw, John M

    2015-09-15

    Clays, in tailings, are a significant ongoing environmental concern in the mining and oilsands production industries, and clay rehabilitation following contamination poses challenges episodically. Understanding the fundamentals of clay behavior can lead to better environmental impact mitigation strategies. Systematic calorimetric measurements are shown to provide a framework for parsing the synergistic and antagonistic impacts of trace (i.e., parts per million level) components on the surface compositions of clays. The enthalpy of solution of as-received and "contaminated" clays, in as-received and "contaminated" organic solvents and water, at 60 °C and atmospheric pressure, provides important illustrative examples. Clay contamination included pre-saturation of clays with water and organic liquids. Solvent contamination included the addition of trace water to organic solvents and trace organic liquids to water. Enthalpy of solution outcomes are interpreted using a quantitative mass and energy balance modeling framework that isolates terms for solvent and trace contaminant sorption/desorption and surface energy effects. Underlying surface energies are shown to dominate the energetics of the solvent-clay interaction, and organic liquids as solvents or as trace contaminants are shown to displace water from as-received clay surfaces. This approach can be readily extended to include pH, salts, or other effects and is expected to provide mechanistic and quantitative insights underlying the stability of clays in tailings ponds and the behaviors of clays in diverse industrial and natural environments. PMID:26296102

  18. Specific binding of ethanol to cholesterol in organic solvents.

    PubMed

    Daragan, V A; Voloshin, A M; Chochina, S V; Khazanovich, T N; Wood, W G; Avdulov, N A; Mayo, K H

    2000-07-01

    Although ethanol has been reported to affect cholesterol homeostasis in biological membranes, the molecular mechanism of action is unknown. Here, nuclear magnetic resonance (NMR) spectroscopic techniques have been used to investigate possible direct interactions between ethanol and cholesterol in various low dielectric solvents (acetone, methanol, isopropanol, DMF, DMSO, chloroform, and CCl(4)). Measurement of (13)C chemical shifts, spin-lattice and multiplet relaxation times, as well as self-diffusion coefficients, indicates that ethanol interacts weakly, yet specifically, with the HC-OH moiety and the two flanking methylenes in the cyclohexanol ring of cholesterol. This interaction is most strong in the least polar-solvent carbon tetrachloride where the ethanol-cholesterol equilibrium dissociation constant is estimated to be 2 x 10(-3) M. (13)C-NMR spin-lattice relaxation studies allow insight into the geometry of this complex, which is best modeled with the methyl group of ethanol sandwiched between the two methylenes in the cyclohexanol ring and the hydroxyl group of ethanol hydrogen bonded to the hydroxyl group of cholesterol.

  19. Binary Solvent Organization at Silica/Liquid Interfaces: Preferential Ordering in Acetonitrile-Methanol Mixtures.

    PubMed

    Gobrogge, Eric A; Walker, Robert A

    2014-08-01

    Nonlinear vibrational spectroscopy experiments examined solvent organization at the silica/binary solvent interface where the binary solvent consisted of methanol and acetonitrile in varying mole fractions. Data were compared with surface vibrational spectra acquired from silica surfaces exposed to a vapor phase saturated with the same binary solvent mixtures. Changes in vibrational band intensities suggest that methanol ideally adsorbs to the silica/vapor interface but acetonitrile accumulates in excess relative to vapor-phase composition. At the silica/liquid interface, acetonitrile's signal increases until a solution phase mole fraction of ∼0.85. At higher acetonitrile concentrations, acetonitrile's signal decreases dramatically until only a weak signature persists with the neat solvent. This behavior is ascribed to dipole-paired acetonitrile forming a bilayer with the first sublayer associating with surface silanol groups and a second sublayer consisting of weakly associating, antiparallel partners. On the basis of recent simulations, we propose that the second sublayer accumulates in excess. PMID:26277964

  20. Photonic sensing of organic solvents through geometric study of dynamic reflection spectrum

    PubMed Central

    Zhang, Yuqi; Fu, Qianqian; Ge, Jianping

    2015-01-01

    Traditional photonic sensing based on the change of balanced reflection of photonic structures can hardly distinguish chemical species with similar refractive indices. Here a sensing method based on the dynamic reflection spectra (DRS) of photonic crystal gel has been developed to distinguish even homologues, isomers and solvents with similar structures and physical properties. There are inherent relationships between solvent properties, diffusion behaviour and evolution of reflection signals, so that the geometric characteristics of DRS pattern including ascending/descending, colour changes, splitting/merging and curvature of reflection band can be utilized to recognize different organic solvents. With adequate solvents being tested, a database of DRS patterns can be established, which provide a standard to identify an unknown solvent. PMID:26082186

  1. Improved performance of polymer solar cells by using inorganic, organic, and doped cathode buffer layers

    NASA Astrophysics Data System (ADS)

    Taohong, Wang; Changbo, Chen; Kunping, Guo; Guo, Chen; Tao, Xu; Bin, Wei

    2016-03-01

    The interface between the active layer and the electrode is one of the most critical factors that could affect the device performance of polymer solar cells. In this work, based on the typical poly(3-hexylthiophene):[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PCBM) polymer solar cell, we studied the effect of the cathode buffer layer (CBL) between the top metal electrode and the active layer on the device performance. Several inorganic and organic materials commonly used as the electron injection layer in an organic light-emitting diode (OLED) were employed as the CBL in the P3HT:PCBM polymer solar cells. Our results demonstrate that the inorganic and organic materials like Cs2CO3, bathophenanthroline (Bphen), and 8-hydroxyquinolatolithium (Liq) can be used as CBL to efficiently improve the device performance of the P3HT:PCBM polymer solar cells. The P3HT:PCBM devices employed various CBLs possess power conversion efficiencies (PCEs) of 3.0%-3.3%, which are ca. 50% improved compared to that of the device without CBL. Furthermore, by using the doped organic materials Bphen:Cs2CO3 and Bphen:Liq as the CBL, the PCE of the P3HT:PCBM device will be further improved to 3.5%, which is ca. 70% higher than that of the device without a CBL and ca. 10% increased compared with that of the devices with a neat inorganic or organic CBL. Project supported by the National Natural Science Foundation of China (Grant No. 61204014), the “Chenguang” Project (13CG42) supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation, China, and the Shanghai University Young Teacher Training Program of Shanghai Municipality, China.

  2. [A nationwide survey on the use of organic solvents in Japan].

    PubMed

    Inoue, T; Ikeda, M; Ogata, M; Saito, K; Sakurai, H; Takeuchi, Y; Hara, I; Matsushita, T; Hisanaga, N; Ono, Y

    1984-11-01

    A total of 1,179 organic solvent products used as thinners, paint, degreasers, inks, adhesive and others, were collected nationwide from factories of various sizes and kinds in Japan, and analyzed by gas chromatography. Solvent components per sample, frequency of each solvent component, and contents of each component were analyzed and classified by use. Paints, inks, and adhesives which contained nonvolatile substances were analyzed by head space techniques. Seventy-seven percent of all samples, 93% of paints, 85% of thinners, 73% of adhesives, and 52% of degreasers contained mixed organic solvents. The average numbers of solvent components per sample were 4.14 (max. 13) in thinner, 3.29 (max. 7) in paint, 2.23 (max. 5) ink, 2.19 (max. 6) in adhesive, 1.71 (max. 6) in degreaser, when gasoline was excluded. Toluene, xylene, methylalcohol, isopropylalcohol, ethylacetate, methylethylketone, industrial gasoline were widely used in the above-mentioned products. Toluene was the most popular component in the solvent products, excluding degreasers. Many kinds of solvent components were used in thinner and paint. However, toluene, xylene and industrial gasoline were their main components and contents per sample were very high. Acetates, alcohols, ketones and glycols were frequently detected in solvent products, but their contents per sample were relatively low, because these solvent components were usually used as subordinate solvents. The chlorinated hydrocarbons such as trichloroethylene, tetrachloroethylene and 1,1,1-trichloroethane, and industrial gasoline were the most popular components in degreasers. 1,4-dioxane was detected in a relatively large number of the samples, but its content per sample was very low, because it is usually used as an additive to 1,1,1-trichloroethane. Toluene was the most popular component in ink solvents, too. In addition, isopropylacohol, methylalcohol, methylethylketone were frequently detected in inks. Toluene was also the most popular

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

    SciTech Connect

    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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25320701

  5. A push-pull organic dye with a quinoidal thiophene linker: Photophysical properties and solvent effects

    NASA Astrophysics Data System (ADS)

    Climent, Clàudia; Carreras, Abel; Alemany, Pere; Casanova, David

    2016-10-01

    In the present work we perform a computational study of the properties of a push-pull organic dye with a quinoidal thiophene unit as the conjugated linker between the electron donor and acceptor groups. We investigate the photophysical properties of the dye related to its potential use as a molecular sensitizer in dye-sensitized solar cells. We rationalize the solvation effects on the absorption band of the dye in protic and aprotic solvents, identifying the interaction of alcohol solvents with the amine in the donor group as the source for the blue shift of the absorption band with respect to aprotic solvents.

  6. Efficient and Specific Trypsin Digestion of Microgram to Nanogram Quantities of Proteins in Organic-Aqueous Solvent Systems

    SciTech Connect

    Strader, Michael B; Tabb, Dave L; Hervey, IV, William Judson; Pan, Chongle; Hurst, Gregory {Greg} B

    2006-01-01

    Mass spectrometry-based identification of the components of multiprotein complexes often involves solution-phase proteolytic digestion of the complex. The affinity purification of individual protein complexes often yields nanogram to low-microgram amounts of protein, which poses several challenges for enzymatic digestion and protein identification. We tested different solvent systems to optimize trypsin digestions of samples containing limited amounts of protein for subsequent analysis by LC-MS-MS. Data collected from digestion of 10-, 2-, 1-, and 0.2- g portions of a protein standard mixture indicated that an organicaqueous solvent system containing 80% acetonitrile consistently provided the most complete digestion, producing more peptide identifications than the other solvent systems tested. For example, a 1-h digestion in 80% acetonitrile yielded over 52% more peptides than the overnight digestion of 1 g of a protein mixture in purely aqueous buffer. This trend was also observed for peptides from digested ribosomal proteins isolated from Rhodopseudomonas palustris. In addition to improved digestion efficiency, the shorter digestion times possible with the organic solvent also improved trypsin specificity, resulting in smaller numbers of semitryptic peptides than an overnight digestion protocol using an aqueous solvent. The technique was also demonstrated for an affinityisolated protein complex, GroEL. To our knowledge, this report is the first using mass spectrometry data to show a linkage between digestion solvent and trypsin specificity. Mass spectrometry (MS) has become a widely used method for studying proteins, protein complexes, and whole proteomes because of innovations in soft ionization techniques, bioinformatics, and chromatographic separation techniques.1-7 An example of a high-throughput mass spectrometry strategy commonly used for this purpose is a variation of the "shotgun" approach, involving in-solution digestion of a protein complex followed by

  7. Artificially MoO3 graded ITO anodes for acidic buffer layer free organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Lee, Hye-Min; Kim, Seok-Soon; Kim, Han-Ki

    2016-02-01

    We report characteristics of MoO3 graded ITO anodes prepared by a RF/DC graded sputtering for acidic poly(3,4-ethylene dioxylene thiophene):poly(styrene sulfonic acid) (PEDOT:PSS)-free organic solar cells (OSCs). Graded sputtering of the MoO3 buffer layer on top of the ITO layer produced MoO3 graded ITO anodes with a sheet resistance of 12.67 Ω/square, a resistivity of 2.54 × 10-4 Ω cm, and an optical transmittance of 86.78%, all of which were comparable to a conventional ITO anode. In addition, the MoO3 graded ITO electrode showed a greater work function of 4.92 eV than that (4.6 eV) of an ITO anode, which is beneficial for hole extraction from an organic active layer. Due to the high work function of MoO3 graded ITO electrodes, the acidic PEDOT:PSS-free OSCs fabricated on the MoO3 graded ITO electrode exhibited a power conversion efficiency 3.60% greater than that of a PEDOT:PSS-free OSC on the conventional ITO anode. The successful operation of PEDOT:PSS-free OSCs indicates simpler fabrication steps for cost-effective OSCs and elimination of interfacial reactions caused by the acidic PEDOT:PSS layer for reliable OSCs.

  8. Investigations on the activity of poly(2-oxazoline) enzyme conjugates dissolved in organic solvents.

    PubMed

    Konieczny, Stefan; Krumm, Christian; Doert, Dominik; Neufeld, Katharina; Tiller, Joerg C

    2014-07-10

    The use of enzymes in organic solvents offers a great opportunity for the highly selective synthesis of complex organic compounds. In this study we investigate the POXylation of several enzymes with different polyoxazolines ranging from the hydrophilic poly(2-methyl-oxazoline) (PMOx) to the hydrophobic poly(2-heptyl-oxazoline) (PHeptOx). As reported previously on the examples of model enzymes POXylation mediated by pyromellitic acid dianhydride results in highly modified, organosoluble protein conjugates. This procedure is here extended to a larger number of proteins and optimized for the different polyoxazolines. The resulting polymer-enzyme conjugates (PEC) became soluble in different organic solvents ranging from hydrophilic DMF to even toluene. These conjugates were characterized regarding their solubility and especially their activity in organic solvents and in some cases the PECs showed significantly (up to 153,000 fold) higher activities than the respective native enzymes. PMID:24709400

  9. 40 CFR Table 4 to Subpart Nnnn of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in... formulation data. Solvent type Average organic HAP mass fraction Typical organic HAP, percent by...

  10. 40 CFR Table 6 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in... formulation data. Solvent type Average organic HAP mass fraction Typical organic HAP, percent by...

  11. 40 CFR Table 4 to Subpart Nnnn of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in... formulation data. Solvent type Average organic HAP mass fraction Typical organic HAP, percent by...

  12. 40 CFR Table 4 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2010 CFR

    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...

  13. 40 CFR Table 4 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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...

  14. 40 CFR Table 4 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups 1

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Petroleum Solvent Groups 1 You May Use the Mass Fraction Values in the...: Solvent type Average organic HAP mass fraction Typical organic percent HAP, by mass Aliphatic 2 0.03...

  15. 40 CFR Table 4 to Subpart Nnnn of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in... formulation data. Solvent type Average organic HAP mass fraction Typical organic HAP, percent by...

  16. 40 CFR Table 4 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for... MMMM of Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass... manufacturer's formulation data. Solvent type Average organic HAP mass fraction Typical organic HAP, percent...

  17. 40 CFR Table 4 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for... MMMM of Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass... manufacturer's formulation data. Solvent type Average organic HAP mass fraction Typical organic HAP, percent...

  18. 40 CFR Table 4 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for... MMMM of Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass... manufacturer's formulation data. Solvent type Average organic HAP mass fraction Typical organic HAP, percent...

  19. 40 CFR Table 4 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups 1

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Petroleum Solvent Groups 1 You May Use the Mass Fraction Values in the...: Solvent type Average organic HAP mass fraction Typical organic percent HAP, by mass Aliphatic 2 0.03...

  20. 40 CFR Table 6 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for...—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in... formulation data. Solvent type Average organic HAP mass fraction Typical organic HAP, percent by...

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

    PubMed

    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.

  2. Incineration of contaminated organic solvents in a fluidized-bed calciner

    SciTech Connect

    Schindler, R.E.

    1980-01-01

    The reprocessing of expended reactor fuels at the Idaho Chemical Processing Plant (ICPP) generates contaminated organic solvents. An evaluation of potential management alternatives shows that several are suitable for management of contaminated solvents containing tri-butyl phosphate (TBP): the solvent could be burned in a commercially-available burner which absorbs the phosphorus on a fluidized-bed of limestone leaving a solid product for burial; the solvent could be burned in a small fluidized-bed calciner which solidifies non-radioactive feed by in-bed combustion of the contaminated solvent. The fluidized-bed absorbs the phosphate forming a solid product for burial; the solvents could be solidified with a gel or sorbant for burial if the reprocessing system were modified to reduce the solvent volume; and the contaminated solvent could be burned in an existing fluidized-bed calciner designed for solidifying high-level aqueous wastes. Burning the solvent in the existing calciner was selected for process verification because it provides an existing burner, off-gas system, and solids transfer and storage system. No additional wastes are generated. A set of four pilot-plant tests verified the absence of adverse effects from the phosphorus in the fuel when calcining simulated ICPP aqueous wastes. Essentially all of the phosphorus remained in the calcined solids with only a neglegible quantity remaining in the scrubbed off-gas. Combustion efficiency was high (93 to 96%). There were no observable adverse effects on solids in the scrubbing system, corrosion rates, or solids flowability (for retrieval). Conclusions of general applicability are: alternative technologies are available for disposal of contaminated solvents, and the use of an existing fuel-using facility, e.g., calciner or incinerator - designed for contaminated wastes will usually be cost effective.

  3. Screening and isolation of an organic solvent-tolerant bacterium for high-yield production of organic solvent-stable protease.

    PubMed

    Tang, X Y; Pan, Y; Li, S; He, B F

    2008-10-01

    Forty-three strains were screened from crude oil-contaminated samples by toluene and cyclohexane enrichment in medium. Ten of these strains demonstrated high protease activity on skim-milk agar. Among them, the PT121 isolate, identified as Pseudomonas aeruginosa, was selected based on its extracellular protease stability in the presence of hydrophilic organic solvents. The crude protease also retained most of its activity up to at least 14 days in the presence of various organic solvents at 50% concentration, and the protease activity in production medium was 10,876U/ml after 72h incubation. This protease showed high activity as a catalyst for aspartame precursor Cbz-Asp-Phe-NH2 synthesis in the presence of 50% dimethylsulfoxide (DMSO).

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

    PubMed

    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.

  5. The influence of organic solvents on estimates of genotoxicity and antigenotoxicity in the SOS chromotest

    PubMed Central

    Quintero, Nathalia; Stashenko, Elena E.; Fuentes, Jorge Luis

    2012-01-01

    In this work, the toxicity and genotoxicity of organic solvents (acetone, carbon tetrachloride, dichloromethane, dimethylsulfoxide, ethanol, ether and methanol) were studied using the SOS chromotest. The influence of these solvents on the direct genotoxicity induced by the mutagens mitomycin C (MMC) and 4-nitroquinoline-1-oxide (4-NQO) were also investigated. None of the solvents were genotoxic in Escherichia coli PQ37. However, based on the inhibition of protein synthesis assessed by constitutive alkaline phosphatase activity, some solvents (carbon tetrachloride, dimethylsulfoxide, ethanol and ether) were toxic and incompatible with the SOS chromotest. Solvents that were neither toxic nor genotoxic to E. coli (acetone, dichloromethane and methanol) significantly reduced the genotoxicity of MMC and 4-NQO. When these solvents were used to dissolve vitamin E they increased the antigenotoxic activity of this compound, possibly through additive or synergistic effects. The relevance of these results is discussed in relation to antigenotoxic studies. These data indicate the need for careful selection of an appropriate diluent for the SOS chromotest since some solvents can modulate genotoxicity and antigenotoxicity. PMID:22888301

  6. Removal of ion-implanted photoresists on GaAs using two organic solvents in sequence

    NASA Astrophysics Data System (ADS)

    Oh, Eunseok; Na, Jihoon; Lee, Seunghyo; Lim, Sangwoo

    2016-07-01

    Organic solvents can effectively remove photoresists on III-V channels without damage or etching of the channel material during the process. In this study, a two-step sequential photoresist removal process using two different organic solvents was developed to remove implanted ArF and KrF photoresists at room temperature. The effects of organic solvents with either low molar volumes or high affinities for photoresists were evaluated to find a proper combination that can effectively remove high-dose implanted photoresists without damaging GaAs surfaces. The performance of formamide, acetonitrile, nitromethane, and monoethanolamine for the removal of ion-implanted ArF and KrF photoresists were compared using a two-step sequential photoresist removal process followed by treatment in dimethyl sulfoxide (DMSO). Among the various combinations, the acetonitrile + DMSO two-step sequence exhibited the best removal of photoresists that underwent ion implantation at doses of 5 × 1013-5 × 1015 atoms/cm2 on both flat and trench-structured GaAs surfaces. The ability of the two-step process using organic solvents to remove the photoresists can be explained by considering the affinities of solvents for a polymer and its permeability through the photoresist.

  7. The Effect of Solvent on the Analysis of Secondary Organic Aerosol Using Electrospray Ionization Mass Spectrometry

    SciTech Connect

    Bateman, Adam P.; Walser, Maggie L.; Dessiaterik, Yury; Laskin, Julia; Laskin, Alexander; Nizkorodov, Serguei

    2008-08-29

    Solvent-analyte reactions in organic aerosol (OA) extracts prepared for analysis by electrospray ionization mass spectrometry (ESI-MS) were examined. Secondary organic aerosol (SOA) produced by ozonation of d-limonene as well as several test organic chemicals with functional groups typical for OA constituents were dissolved and stored in methanol, d3-methanol, acetonitrile, and d3-acetonitrile to investigate the extent and relative rates of reactions between analyte and solvent. High resolution ESI-MS showed that reactions of carbonyls with methanol produce significant amounts of hemiacetals and acetals on time scales ranging from several minutes to several days, with the reaction rates increasing in acidified solutions. Carboxylic acid groups were observed to react with methanol resulting in the formation of esters. In contrast, acetonitrile extracts showed no evidence of reactions with analyte molecules, suggesting that acetonitrile is the preferred solvent for SOA extraction. The use of solvent-analyte reactivity as an analytical chemistry tool for the improved characterization of functional groups in complex organic mixtures was also demonstrated. Direct comparison between ESI mass spectra of the same SOA samples extracted in reactive (methanol) versus non-reactive (acetonitrile) solvents was used to estimate the relative fractions of ketones (≥38%), aldehydes (≥6%), and carboxylic acids (≥55%) in d-limonene SOA.

  8. Preparation of graphene sponge by vapor phase reduction for oil and organic solvent removal

    NASA Astrophysics Data System (ADS)

    Wu, Ruihan; Yu, Baowei; Jin, Xinyan; Liu, Xiaoyang; Bai, Yitong; Chen, Lingyun; Ming, Zhu; Yang, Hua; Yang, Sheng-Tao; Luo, Jianbin

    2016-10-01

    Due to the porous structure and hydrophobicity, graphene sponge has huge adsorption capacity for oils and organic solvents. In this study, we reported that graphene sponge could be prepared by vapor phase reduction (denoted as VPRGS) for oil and organic solvent removal. Graphene oxide was lyophilized and reduced by steamy hydrazine hydrate to produce VPRGS. VPRGS had huge capacity for oils and organic solvents (72–224 g g‑1). In particular, the adsorption capacity for crude oil reached 165 g g‑1, suggesting that VPRGS could be applied in oil leakage remediation. VPRGS could treat pollutants both in pure liquid form and in the simulated sea water, where the hydrophobic nature of VPRGS allowed the floating of VPRGS on simulated sea water. VPRGS could be easily regenerated without obvious capacity loss up to 9 cycles. The implications to the applications of VPRGS in oil/water separation and water remediation are discussed.

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

    NASA Technical Reports Server (NTRS)

    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.

  10. Toxic effects of organic solvents on the growth of blue-green algae

    SciTech Connect

    Stratton, G.W.

    1987-06-01

    Relatively few reports have been published on the comparative toxicity of solvents towards test organisms, and these deal primarily with fish and aquatic invertebrates. Information for microbial systems are more limited with some data available for algae and slightly more for fungi. Aside from direct toxic effects of their own, solvents can interact synergistically and antagonistically with the toxicant in solution. This problem has been well documented with pesticides, and a procedure has been developed to identify and eliminate these effects from bioassays. The first step in choosing a solvent for use in microbial bioassays should be a detailed screening to identify solvents with inherently low toxicity to the test organism, followed by an interaction study to choose the best concentration to use. The purpose of the present study was to compare the inhibitory effects of six solvents commonly used in pesticide bioassays towards five species of blue-green algae (cyanobacteria), in order to identify solvents with low toxicity for use in bioassays.

  11. Vapor-phase interactions and diffusion of organic solvents in the unsaturated zone

    USGS Publications Warehouse

    Roy, W.R.; Griffin, R.A.

    1990-01-01

    This article presents an analysis of the interactions and static movement of 37 organic solvents as vapors through the unsaturated soil zone. The physicochemical interactions of the organic vapors with unsaturated soil materials were emphasized with focus on diffusive, and adsorptive interactions. Fick's Law and porous media diffusion coefficients for most of the solvent vapors were either compiled or estimated; coefficients were not available for some of the fluorinated solvents. The adsorption of some of the solvent vapors by silica was concluded to be due to hydrogen bond formation with surface silanol groups. Heats of adsorption data for different adsorbents were also compiled. There were very few data on the adsorption of these solvent vapors by soils, but it appears that the magnitude of adsorption of nonpolar solvents is reduced as the relative humidity of the vapor-solid system is increased. Consequently, the interaction of the vapors may then separated into two processes; (1) gas-water partitioning described by Henry's Law constants, and (2) solid-water adsorption coefficients which may be estimated from liquid-solid partition coefficients (Kd values). ?? 1990 Springer-Verlag New York Inc.

  12. Uncovering the role of cathode buffer layer in organic solar cells

    PubMed Central

    Qi, Boyuan; Zhang, Zhi-Guo; Wang, Jizheng

    2015-01-01

    Organic solar cells (OSCs) as the third generation photovoltaic devices have drawn intense research, for their ability to be easily deposited by low-cost solution coating technologies. However the cathode in conventional OSCs, Ca, can be only deposited by thermal evaporation and is highly unstable in ambient. Therefore various solution processible cathode buffer layers (CBLs) are synthesized as substitute of Ca and show excellent effect in optimizing performance of OSCs. Yet, there is still no universal consensus on the mechanism that how CBL works, which is evidently a critical scientific issue that should be addressed. In this article detailed studies are targeted on the interfacial physics at the interface between active layer and cathode (with and without treatment of a polar CBL) by using ultraviolet photoelectron spectroscopy, capacitance-voltage measurement, and impedance spectroscopy. The experimental data demonstrate that CBL mainly takes effect in three ways: suppressing surface states at the surface of active layer, protecting the active layer from being damaged by thermally evaporated cathode, and changing the energy level alignment by forming dipole moments with active layer and/or cathode. Our findings here provide a comprehensive picture of interfacial physics in devices with and without CBL. PMID:25588623

  13. Uncovering the role of cathode buffer layer in organic solar cells.

    PubMed

    Qi, Boyuan; Zhang, Zhi-Guo; Wang, Jizheng

    2015-01-01

    Organic solar cells (OSCs) as the third generation photovoltaic devices have drawn intense research, for their ability to be easily deposited by low-cost solution coating technologies. However the cathode in conventional OSCs, Ca, can be only deposited by thermal evaporation and is highly unstable in ambient. Therefore various solution processible cathode buffer layers (CBLs) are synthesized as substitute of Ca and show excellent effect in optimizing performance of OSCs. Yet, there is still no universal consensus on the mechanism that how CBL works, which is evidently a critical scientific issue that should be addressed. In this article detailed studies are targeted on the interfacial physics at the interface between active layer and cathode (with and without treatment of a polar CBL) by using ultraviolet photoelectron spectroscopy, capacitance-voltage measurement, and impedance spectroscopy. The experimental data demonstrate that CBL mainly takes effect in three ways: suppressing surface states at the surface of active layer, protecting the active layer from being damaged by thermally evaporated cathode, and changing the energy level alignment by forming dipole moments with active layer and/or cathode. Our findings here provide a comprehensive picture of interfacial physics in devices with and without CBL. PMID:25588623

  14. Uncovering the role of cathode buffer layer in organic solar cells

    NASA Astrophysics Data System (ADS)

    Qi, Boyuan; Zhang, Zhi-Guo; Wang, Jizheng

    2015-01-01

    Organic solar cells (OSCs) as the third generation photovoltaic devices have drawn intense research, for their ability to be easily deposited by low-cost solution coating technologies. However the cathode in conventional OSCs, Ca, can be only deposited by thermal evaporation and is highly unstable in ambient. Therefore various solution processible cathode buffer layers (CBLs) are synthesized as substitute of Ca and show excellent effect in optimizing performance of OSCs. Yet, there is still no universal consensus on the mechanism that how CBL works, which is evidently a critical scientific issue that should be addressed. In this article detailed studies are targeted on the interfacial physics at the interface between active layer and cathode (with and without treatment of a polar CBL) by using ultraviolet photoelectron spectroscopy, capacitance-voltage measurement, and impedance spectroscopy. The experimental data demonstrate that CBL mainly takes effect in three ways: suppressing surface states at the surface of active layer, protecting the active layer from being damaged by thermally evaporated cathode, and changing the energy level alignment by forming dipole moments with active layer and/or cathode. Our findings here provide a comprehensive picture of interfacial physics in devices with and without CBL.

  15. Study on effects of organic solvents on Hela cells by digital holography

    NASA Astrophysics Data System (ADS)

    Ouyang, Liting; Wang, Dayong; Wang, Yunxin; Wang, Xinlong; Marx, Lisa

    2012-11-01

    In the anticancer research with traditional Chinese medicine, many medicinally effective components can only dissolve in higher polar organic solvents, such as ethanol, dimethyl sulfoxide (DMSO) etc. However, organic solvents may directly interfere with the accuracy of therapeutic efficacy evaluation. Therefore the study on effects of organic solvents with different concentrations on Hela cells is of great significance. The digital holography is a non-destructive and non-contact method to image the transparent sample without staining and with the high precision and high resolution. In this paper, the digital holography is proposed to replace the methyl-thiazol-tetrazolium (MTT) or the Giemsa dye method. Based on the pre-magnification off-axis Fresnel digital holographic theory, an inverted microscopy system is built to obtain the phase-contrast images of the Hela cells, which are added different concentrations of organic solvents. Compared to the control group, there is significantly differences with the shapes of Hela cells with different organic solvents. The size of cell with ethanol 25% is no significantly difference with the control group. But the sizes of cells in the solutions with ethanol 12.5% and 50% are smaller than the control group. Next, the sizes of cells in the solutions with DMSO 12.5%, 25% and 50% are great smaller, compared with the control group. The results show that the digital holography has high practical value in detecting the changes in the shape of cells and is helpful in the choice of organic solvents for further apoptosis study.

  16. Dynamic solvation shell and solubility of C60 in organic solvents.

    PubMed

    Wang, Chun I; Hua, Chi C; Chen, Show A

    2014-08-21

    The notion of (static) solvation shells has recently proved fruitful in revealing key molecular factors that dictate the solubility and aggregation properties of fullerene species in polar or ionic solvent media. Using molecular dynamics schemes with carefully evaluated force fields, we have scrutinized both the static and the dynamic features of the solvation shells of single C60 particle for three nonpolar organic solvents (i.e., chloroform, toluene, and chlorobenzene) and a range of system temperatures (i.e., T = 250-330 K). The central findings have been that, while the static structures of the solvation shell remain, in general, insensitive to the effects of changing solvent type or system temperature, the dynamic behavior of solvent molecules within the shell exhibits prominent dependence on both factors. Detailed analyses led us to propose the notion of dynamically stable solvation shell, effectiveness of which can be characterized by a new physical parameter defined as the ratio of two fundamental time constants representing, respectively, the solvent relaxation (or residence) time within the first solvation shell and the characteristic time required for the fullerene particle to diffuse a distance comparable to the shell thickness. We show that, for the five (two from the literature) different solvent media and the range of system temperatures examined herein, this parameter bears a value around unity and, in particular, correlates intimately with known trends of solubility for C60 solutions. We also provide evidence revealing that, in addition to fullerene-solvent interactions, solvent-solvent interactions play an important role, too, in shaping the dynamic solvation shell, as implied by recent experimental trends. PMID:25084556

  17. Growth of lanthanum manganate buffer layers for coated conductors via a metal-organic decomposition process

    NASA Astrophysics Data System (ADS)

    Venkataraman, Kartik

    LaMnO3 (LMO) was identified as a possible buffer material for YBa2Cu3O7-x conductors due to its diffusion barrier properties and close lattice match with YBa2Cu 3O7-x. Growth of LMO films via a metal-organic decomposition (MOD) process on Ni, Ni-5at.%W (Ni-5W), and single crystal SrTiO3 substrates was investigated. Phase-pure LMO was grown via MOD on Ni and SrTiO 3 substrates at temperatures and oxygen pressures within a thermodynamic "process window" wherein LMO, Ni, Ni-5W, and SrTiO3 are all stable components. LMO could not be grown on Ni-5W in the "process window" because tungsten diffused from the substrate into the overlying film, where it reacted to form La and Mn tungstates. The kinetics of tungstate formation and crystallization of phase-pure LMO from the La and Mn acetate precursors are competitive in the temperature range explored (850--1100°C). Temperatures <850°C might mitigate tungsten diffusion from the substrate to the film sufficiently to obviate tungstate formation, but LMO films deposited via MOD require temperatures ≥850°C for nucleation and grain growth. Using a Y2O3 seed layer on Ni-5W to block tungsten from diffusing into the LMO film was explored; however, Y2O3 reacts with tungsten in the "process window" at 850--1100°C. Tungsten diffusion into Y2O3 can be blocked if epitaxial, crack-free NiWO4 and NiO layers are formed at the interface between Ni-5W and Y2O3. NiWO 4 only grows epitaxially if the overlying NiO and buffer layers are thick enough to mechanically suppress (011)-oriented NiWO4 grain growth. This is not the case when a bare 75 nm-thick Y2O3 film on Ni-5W is processed at 850°C. These studies show that the Ni-5W substrate must be at a low temperature to prevent tungsten diffusion, whereas the LMO precursor film must be at elevated temperature to crystallize. An excimer laser-assisted MOD process was used where a Y2O 3-coated Ni-5W substrate was held at 500°C in air and the pulsed laser photo-thermally heated the Y2O3 and LMO

  18. Reactions of metallic Li or LiC6 with organic solvents for lithium ion battery

    NASA Astrophysics Data System (ADS)

    Nakajima, Tsuyoshi; Hirobayashi, Yuki; Takayanagi, Yuki; Ohzawa, Yoshimi

    2013-12-01

    DSC (Differential Scanning Calorimetry) study has been made on the reactions of metallic Li or LiC6 with organic solvents for lithium ion battery. Ethylene carbonate (EC) more easily reacts with metallic Li and LiC6 than propylene carbonate (PC). This may be because formation of lithium alkyl carbonate is more difficult for PC than EC. On the other hand, diethyl carbonate (DEC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) react with Li in the same manner. Reactions of Li and LiC6 with organic solvents have been discussed based on the results of quantum calculation.

  19. Analysis of partitioning of organic compounds and proteins in aqueous polyethylene glycol-sodium sulfate aqueous two-phase systems in terms of solute-solvent interactions.

    PubMed

    da Silva, Nuno R; Ferreira, Luisa A; Madeira, Pedro P; Teixeira, José A; Uversky, Vladimir N; Zaslavsky, Boris Y

    2015-10-01

    Partition behavior of nine small organic compounds and six proteins was examined in poly(ethylene glycol)-8000-sodium sulfate aqueous two-phase systems containing 0.5M osmolyte (sorbitol, sucrose, trehalose, TMAO) and poly(ethylene glycol)-10000-sodium sulfate system, all in 0.01M sodium phosphate buffer, pH 6.8. The differences between the solvent properties of the coexisting phases (solvent dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity) were characterized with solvatochromic dyes using the solvatochromic comparison method. Differences between the electrostatic properties of the phases were determined by analysis of partitioning of sodium salts of dinitrophenylated (DNP-) amino acids with aliphatic alkyl side-chain. It was found out that the partition coefficient of all compounds examined (including proteins) may be described in terms of solute-solvent interactions. The results obtained in the study show that solute-solvent interactions of nonionic organic compounds and proteins in polyethylene glycol-sodium sulfate aqueous two-phase system differ from those in polyethylene glycol-dextran system. PMID:26342872

  20. 40 CFR Table 5 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for... OOOO of Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass... manufacturer's formulation data: Solvent type Averageorganic HAP mass fraction Typical organic HAP, percent...

  1. 40 CFR Table 4 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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...

  2. 40 CFR Table 4 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for... of Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass... manufacturer's formulation data Solvent type Averageorganic HAP mass fraction Typical organic HAP, percent...

  3. 40 CFR Table 4 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2010 CFR

    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...

  4. 40 CFR Table 5 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for... OOOO of Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass... manufacturer's formulation data: Solvent type Averageorganic HAP mass fraction Typical organic HAP, percent...

  5. 40 CFR Table 4 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false 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...

  6. 40 CFR Table 5 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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...

  7. 40 CFR Table 4 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for... of Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass... manufacturer's formulation data Solvent type Averageorganic HAP mass fraction Typical organic HAP, percent...

  8. 40 CFR Table 4 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for... of Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass... manufacturer's formulation data Solvent type Averageorganic HAP mass fraction Typical organic HAP, percent...

  9. 40 CFR Table 5 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for... OOOO of Part 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass... manufacturer's formulation data: Solvent type Averageorganic HAP mass fraction Typical organic HAP, percent...

  10. 40 CFR Table 5 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2010 CFR

    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...

  11. 40 CFR Table 4 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2010 CFR

    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...

  12. 40 CFR Table 4 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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...

  13. 40 CFR Table 4 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false 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...

  14. Critical CuI buffer layer surface density for organic molecular crystal orientation change

    SciTech Connect

    Ahn, Kwangseok; Kim, Jong Beom; Lee, Dong Ryeol; Kim, Hyo Jung; Lee, Hyun Hwi

    2015-01-21

    We have determined the critical surface density of the CuI buffer layer inserted to change the preferred orientation of copper phthalocyanine (CuPc) crystals grown on the buffer layer. X-ray reflectivity measurements were performed to obtain the density profiles of the buffer layers and out-of-plane and 2D grazing-incidence X-ray diffraction measurements were performed to determine the preferred orientations of the molecular crystals. Remarkably, it was found that the preferred orientation of the CuPc film is completely changed from edge-on (1 0 0) to face-on (1 1 −2) by a CuI buffer layer with a very low surface density, so low that a large proportion of the substrate surface is bare.

  15. Organic aqueous tunable solvents (OATS): a vehicle for coupling reactions and separations.

    PubMed

    Pollet, Pamela; Hart, Ryan J; Eckert, Charles A; Liotta, Charles L

    2010-09-21

    In laboratory-based chemical synthesis, the choice of the solvent and the means of product purification are rarely determined by cost or environmental impact considerations. When a reaction is scaled up for industrial applications, however, these choices are critical: the separation of product from the solvent, starting materials, and byproduct usually constitutes 60-80% of the overall cost of a process. In response, researchers have developed solvents and solvent-handling methods to optimize both the reaction and the subsequent separation steps on the manufacturing scale. These include "switchable" solvents, which are designed so that their physical properties can be changed abruptly, as well as "tunable" solvents, wherein the solvent's properties change continuously through the application of an external stimulus. In this Account, we describe the organic aqueous tunable solvent (OATS) system, examining two instructive and successful areas of application of OATS as well as its clear potential for further refinement. OATS systems address the limitations of biphasic processes by optimizing reactions and separations simultaneously. The reaction is performed homogeneously in a miscible aqueous-organic solvent mixture, such as water-tetrahydrofuran (THF). The efficient product separation is conducted heterogeneously by the simple addition of modest pressures of CO(2) (50-60 bar) to the system. Under these conditions, the water-THF phase splits into two relatively immiscible phases: the organic THF phase contains the hydrophobic product, and the aqueous phase contains the hydrophilic catalyst. We take advantage of the unique properties of OATS to develop environmentally benign and cost-competitive processes relevant in industrial applications. Specifically, we describe the use of OATS for optimizing the reaction, separation, design, and recycling of (i) Rh-catalyzed hydroformylation of olefins such as 1-octene and (ii) enzyme-catalyzed hydrolysis of 2-phenylacetate. We

  16. Calorimetric Investigation of Hydrogen Bonding of Formamide and Its Methyl Derivatives in Organic Solvents and Water

    NASA Astrophysics Data System (ADS)

    Varfolomeev, Mikhail A.; Rakipov, Ilnaz T.; Solomonov, Boris N.

    2013-04-01

    Formamide and its derivatives have a large number of practical applications; also they are structural fragments of many biomolecules. Hydrogen bonds strongly affect their physicochemical properties. In the present work a calorimetric study of formamide and its methyl derivatives was carried out. Enthalpies of solution at infinite dilution of formamide, N-methylformamide, and N, N-dimethylformamide in organic solvents at 298.15 K were measured. The relationships between the obtained enthalpies of solvation and the structure of the studied compounds were observed. Hydrogen-bond enthalpies of amides with chlorinated alkanes, ethers, ketones, esters, nitriles, amines, alcohols, and water were determined. The strength of hydrogen bonds of formamide, N-methylformamide, and N, N-dimethylformamide with proton donor solvents is practically equal. Enthalpies of hydrogen bonds of formamide with the proton acceptor solvents are two times larger in magnitude than the enthalpies of N-methylformamide. The process of hydrogen bonding of amides in aliphatic alcohols and water is complicated. The obtained enthalpies of hydrogen bonding in aliphatic alcohols vary considerably from the amide structure due to the competition between solute-solvent and solvent-solvent hydrogen bonds. Fourier transform infrared spectroscopic measurements were carried out to explain the calorimetric data. Hydration enthalpies of methyl derivatives of formamides contain a contribution of the hydrophobic effect. New thermochemical data on the hydrogen bonding of formamides may be useful for predicting the properties of biomacromolecules.

  17. Micellization of alkyl-propoxy-ethoxylate surfactants in water-polar organic solvent mixtures.

    PubMed

    Sarkar, Biswajit; Lam, Stephanie; Alexandridis, Paschalis

    2010-07-01

    The effects of cosolvents (glycerol, ethanol, and isopropanol) on the self-assembly of novel alkyl-propoxy-ethoxylate surfactants in aqueous solutions have been investigated with a focus on the (i) quantification of solvent effects on the critical micelle concentration (cmc), (ii) free-energy contributions to micellization, (iii) local environment in the micellar solution, and (iv) structure of the micelles. The introduction of the polar organic solvents considered in this work into water decreases cohesive forces in the solvent mixture, resulting in an increase in the solubility of the surfactant molecules. As a result, micelle formation becomes less favorable and the cmc increases. The contribution of the cosolvent to the free energy of micellization is positive, and the data for different mixed solvents collapse onto a single straight line when plotted versus a function of the solubility parameters of the surfactant alkyl chains and the mixed solvents. The behavior of the poly(propylene oxide) part of the alkyl-propoxy-ethoxylate surfactants is hydrophilic, albeit less so in the ethanol-water mixed solvent than in plain water. Pyrene fluorescence emission I(1)/I(3) data suggest that the microenvironment in micellar solutions is affected mainly by the cosolvent concentration, not the surfactant degree of ethoxylation. Small-angle X-ray scattering data for both water and ethanol-water surfactant solutions are consistent with oblate ellipsoid micelles and reveal that the introduction of 20% ethanol decreases the micelle long axis by 10-15%.

  18. Effect of various organic solvents on rheological properties of wood

    NASA Astrophysics Data System (ADS)

    Sugimoto, H.; Miki, T.; Nishida, M.; Kanayama, K.

    2008-08-01

    Plastics depend strongly on underground resources such as petroleum. To produce novel wood materials as a substitute for plastics, the fine structure of wood impregnated with various organic solvents—ethylene glycol(EG), tri-ethylene glycol, dimethyl folmamyde(DMF), dimethyl sulfoxide(DMSO)—was examined. The dynamic Young's modulus and tanδ—frequency curves of every sample indicated that the relaxation process due to the glass transition of lignin in wood exists. To obtain basic data about the processes, the apparent activation energies (ΔE) were examined. The values of ΔE of the sample impregnated with water and EG were higher than that with DMSO and DMF. These results may not only be due to the hydrogen bonding per volume, but also the confined effect in wood. In fact, the CP/MAS spectra of EG—Wood sample indicates the existence of slow movement EG at higher temperatures of the melting point.

  19. Emission of volatile organic compounds to the atmosphere in the solvent sublation process. II. Volatile chlorinated organic compounds

    SciTech Connect

    Ososkov, V.; Kebbekus, B.; Chou, C.C.

    1996-06-01

    The mass of trichloroethylene, chlorobenzene, and 1,3-dichlorobenzene removed from an aqueous solution and emitted to the atmosphere during solvent sublation was determined experimentally. It was shown that the emission of these compounds in solvent sublation was reduced by 30 to 85% over air stripping under the same experimental conditions. The efficiency of removal of these compounds from water was also studied. The reduction of emissions over air stripping was more effective for the more hydrophobic and less volatile compounds. Emissions are reduced as the thickness of organic layer on the top of the column is increased. The use of decyl alcohol as the layer compound decreases emissions to a greater extent than does paraffin oil. Removal of these chlorinated volatile organic compounds from water by solvent sublation at an elevated temperature of 45{degrees}C is significantly faster than at room temperature. However, the emissions to the atmosphere are also increased.

  20. The Relationship of Liver Function Tests to Mixed Exposure to Lead and Organic Solvents

    PubMed Central

    2013-01-01

    Objective This study aims to compare liver function indices (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and gamma glutamyl transferase [GGT]) among males who work with lead, organic solvents, or both lead and organic solvents, under the permissible exposure limit (PEL). Methods A total of 593 (out of 2,218) male workers who agreed to share their personal health information for medical research were selected for this study. Those excluded were hepatitis B carriers, individuals exposed to occupational risk factors other than lead and organic solvents, and individuals without liver function results. The 593 were divided into five groups: a lead-exposed group, an organic solvent-exposed group exposed to trichloroethylene (TCE co-exposed solvent group), an organic solvent-exposed group not exposed to trichloroethylene (TCE non-exposed solvent group), a lead and organic solvent-exposed group (mixed exposure group), and a non-exposed group (control group). We performed a one way-analysis of variance (one way-ANOVA) test to compare the geometric means of liver function indices among the groups, using a general linear model (GLM) to adjust for age, work duration, body mass index (BMI), smoking, and alcohol intake. In addition, we performed a binary logistic regression analysis to compare the odds ratios among groups with an abnormal liver function index, according to a cut-off value. Results The ALT and AST of the mixed exposure group were higher than those of the other groups. The GGT of the mixed exposure group was higher than the TCE co-exposed solvent group, but there was no difference among the control group, TCE non-exposed solvent group, lead-exposed group, and mixed exposure group. The same result was evident after adjusting by GLM for age, work duration, BMI, smoking, and alcohol intake, except that ALT from the mixed exposure group showed no difference from the TCE co-exposed solvent group. When the cut-off values of the AST, ALT, and GGT

  1. Random mutagenesis and selection of organic solvent-stable haloperoxidase from Streptomyces aureofaciens.

    PubMed

    Yamada, Ryosuke; Higo, Tatsutoshi; Yoshikawa, Chisa; China, Hideyasu; Yasuda, Masahiro; Ogino, Hiroyasu

    2015-01-01

    Haloperoxidases are useful oxygenases involved in halogenation of a range of water-insoluble organic compounds and can be used without additional high-cost cofactors. In particular, organic solvent-stable haloperoxidases are desirable for enzymatic halogenations in the presence of organic solvents. In this study, we adopted a directed evolution approach by error-prone polymerase chain reaction to improve the organic solvent-stability of the homodimeric BPO-A1 haloperoxidase from Streptomyces aureofaciens. Among 1,000 mutant BPO-A1 haloperoxidases, an organic solvent-stable mutant OST48 with P123L and P241A mutations and a high active mutant OST959 with H53Y and G162R mutations were selected. The residual activity of mutant OST48 after incubation in 40% (v/v) 1-propanol for 1 h was 1.8-fold higher than that of wild-type BPO-A1. In addition, the OST48 mutant showed higher stability in methanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide than wild-type BPO-A1 haloperoxidase. Moreover, after incubation at 80°C for 1 h, the residual activity of mutant OST959 was 4.6-fold higher than that of wild-type BPO-A1. Based on the evaluation of single amino acid-substituted mutant models, stabilization of the hydrophobic core derived from P123L mutation and increased numbers of hydrogen bonds derived from G162R mutation led to higher organic solvent-stability and thermostability, respectively.

  2. Impact Of Organic Solvents And Common Anions On 2-Chlorobiphenyl Dechlorination Kinetics With Pd/Mg

    EPA Science Inventory

    The current study evaluates Pd/Mg performance for 2-chlorobiphenyl (2-CB) dechlorination in the presence of naturally abundant anions such as sulfate, chloride, nitrate, hydroxide and carbonates and organic solvents that are used for ex-situ PCB extraction or may accompany PCB co...

  3. Preparation of carbon quantum dots with tunable photoluminescence by rapid laser passivation in ordinary organic solvents.

    PubMed

    Li, Xiangyou; Wang, Hongqiang; Shimizu, Yoshiki; Pyatenko, Alexander; Kawaguchi, Kenji; Koshizaki, Naoto

    2011-01-21

    A simple approach to prepare carbon quantum dots is presented in this communication by laser rapid passivation of nano carbon particles in ordinary organic solvent. The as-prepared carbon dots exhibited visible, tunable and stable photoluminescence (PL). XPS analysis showed that the increased oxygen concentration might be concerned with the origin of PL.

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

    ERIC Educational Resources Information Center

    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.

  5. Organic solvents induce the formation of oil-in-ionic liquid microemulsion aggregations.

    PubMed

    Gao, Yanan; Li, Na; Zhang, Shaohua; Zheng, Liqiang; Li, Xinwei; Dong, Bin; Yu, Li

    2009-02-01

    The role of four organic solvents in the formation process of 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) based ionic liquid (IL) microemulsions is investigated. The results showed that the addition of Triton X-100 remarkably decreased the conductivity of bmimBF4. The added organic solvents provided a strong apolar environment for the hydrophobic tails of Triton X-100 and caused the surfactant molecules to aggregate into the interfacial film of oil-in-bmimBF4 (O/IL) microemulsions. As a result, the conductivities of the solutions were initially increased because the insulative Triton X-100 molecules were assembled, which corresponded to increasing the concentration of continuous bmimBF4 solutions. The hydrophobic interaction between the dispersed organic solvents and the hydrophobic tails of Triton X-100 may be the driving force for the formation of O/IL microemulsions. The droplets of O/IL microemulsions were successively swollen by organic solvents, and a bicontinuous IL-containing microemulsion was observed by freeze-fracture transmission electron microscopy for the first time. The current study can help in further understanding the ILs-containing microemulsions and thereby improve microemulsion theory. PMID:19138136

  6. Elucidation of the mechanism of chiral selectivity in diastereomeric salt formation using organic solvent nanofiltration.

    PubMed

    Ghazali, Nazlee F; Patterson, Darrell A; Livingston, Andrew G

    2004-04-21

    Organic solvent nanofiltration (OSN) was used to investigate the mechanism of chiral selectivity in diastereomeric salt formation of alpha-phenylethylamine with D-tartaric acid and di-p-toluoyl-D-tartaric acid as resolving agents; results indicate that for these systems chiral selectivity occurs only upon crystallisation and chiral interactions in solution were negligible. PMID:15069495

  7. Understanding mechanisms of asphaltene adsorption from organic solvent on mica.

    PubMed

    Natarajan, Anand; Kuznicki, Natalie; Harbottle, David; Masliyah, Jacob; Zeng, Hongbo; Xu, Zhenghe

    2014-08-12

    The adsorption process of asphaltene onto molecularly smooth mica surfaces from toluene solutions of various concentrations (0.01-1 wt %) was studied using a surface forces apparatus (SFA). Adsorption of asphaltenes onto mica was found to be highly dependent on adsorption time and asphaltene concentration of the solution. The adsorption of asphaltenes led to an attractive bridging force between the mica surfaces in asphaltene solution. The adsorption process was identified as being controlled by the diffusion of asphaltenes from the bulk solution to the mica surface with a diffusion coefficient on the order of 10(-10) m(2)/s at room temperature, depending on the asphaltene bulk concentration. This diffusion coefficient corresponds to a hydrodynamic molecular radius of approximately 0.5 nm, indicating that asphaltene diffuses to mica surfaces as individual molecules at very low concentration (e.g., 0.01 wt %). Atomic force microscopy images of the adsorbed asphaltenes on mica support the results of the SFA force measurements. The results from the SFA force measurements provide valuable insights into the molecular interactions (e.g., steric repulsion and bridging attraction as a function of distance) of asphaltenes in organic media and hence their roles in crude oil and bitumen production.

  8. Lanthanide-organic complexes based on polyoxometalates: Solvent effect on the luminescence properties

    SciTech Connect

    Tang Qun; Liu Shuxia; Liang Dadong; Ma Fengji; Ren Guojian; Wei Feng; Yang Yuan; Li Congcong

    2012-06-15

    A series of lanthanide-organic complexes based on polyoxometalates (POMs) [Ln{sub 2}(DNBA){sub 4}(DMF){sub 8}][W{sub 6}O{sub 19}] (Ln=La(1), Ce(2), Sm(3), Eu(4), Gd(5); DNBA=3,5-dinitrobenzoate; DMF=N,N-dimethylformamide) has been synthesized. These complexes consist of [W{sub 6}O{sub 19}]{sup 2-} and dimeric [Ln{sub 2}(DNBA){sub 4}(DMF){sub 8}]{sup 2+} cations. The luminescence properties of 4 are measured in solid state and different solutions, respectively. Notably, the emission intensity increases gradually with the increase of solvent permittivity, and this solvent effect can be directly observed by electrospray mass spectrometry (ESI-MS). The analyses of ESI-MS show that the eight coordinated solvent DMF units of dimeric cation are active. They can move away from dimeric cations and exchange with solvent molecules. Although the POM anions escape from 3D supramolecular network, the dimeric state structure of [Ln{sub 2}(DNBA){sub 4}]{sup 2+} remains unchanged in solution. The conservation of red luminescence is attributed to the maintenance of the aggregated state structures of dimeric cations. - Graphical abstract: 3D POMs-based lanthanide-organic complexes performed the solvent effect on the luminescence property. The origin of such solvent effect can be understood and explained on the basis of the existence of coordinated active sites by the studies of ESI-MS. Highlights: Black-Right-Pointing-Pointer The solvent effect on the luminescence property of POMs-based lanthanide-organic complexes. Black-Right-Pointing-Pointer ESI-MS analyses illuminate the correlation between the structure and luminescence property. Black-Right-Pointing-Pointer The dimeric cations have eight active sites of solvent coordination. Black-Right-Pointing-Pointer The aggregated state structure of dimer cation remains unchanged in solution. Black-Right-Pointing-Pointer Luminescence associating with ESI-MS is a new method for investigating the interaction of complex and solvent.

  9. Experimental Limiting Oxygen Concentrations for Nine Organic Solvents at Temperatures and Pressures Relevant to Aerobic Oxidations in the Pharmaceutical Industry

    PubMed Central

    2015-01-01

    Applications of aerobic oxidation methods in pharmaceutical manufacturing are limited in part because mixtures of oxygen gas and organic solvents often create the potential for a flammable atmosphere. To address this issue, limiting oxygen concentration (LOC) values, which define the minimum partial pressure of oxygen that supports a combustible mixture, have been measured for nine commonly used organic solvents at elevated temperatures and pressures. The solvents include acetic acid, N-methylpyrrolidone, dimethyl sulfoxide, tert-amyl alcohol, ethyl acetate, 2-methyltetrahydrofuran, methanol, acetonitrile, and toluene. The data obtained from these studies help define safe operating conditions for the use of oxygen with organic solvents. PMID:26622165

  10. Covalent modification of graphite oxide with acetic anhydride to enhance dispersibility in organic solvents

    NASA Astrophysics Data System (ADS)

    Li, Jingjing; Yang, Anwei; Zhang, Chen; Zhang, Lei; Sun, Feifei; Ma, Ning

    2016-05-01

    Graphite oxide (GO) was modified by acetic anhydride via a catalyzed ring-opening reaction of the attached epoxy groups at very mild condition. The dispersion of the modified GO is thus largely imporved in many organic solvents and the highest GO concentration reaches 2.0mg/mL in alkyl(aryl) chlorides, ethers, alcohols and cyclohexane, which is amongst the highest value for GO in organics.

  11. Solvent-induced changes in PEDOT:PSS films for organic electrochemical transistors

    SciTech Connect

    Zhang, Shiming; Kumar, Prajwal; Nouas, Amel Sarah; Fontaine, Laurie; Tang, Hao; Cicoira, Fabio

    2015-01-01

    Organic electrochemical transistors based on the conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) are of interest for several bioelectronic applications. In this letter, we investigate the changes induced by immersion of PEDOT:PSS films, processed by spin coating from different mixtures, in water and other solvents of different polarities. We found that the film thickness decreases upon immersion in polar solvents, while the electrical conductivity remains unchanged. The decrease in film thickness is minimized via the addition of a cross-linking agent to the mixture used for the spin coating of the films.

  12. Nickel-Catalyzed Cross-Electrophile Coupling with Organic Reductants in Non-Amide Solvents.

    PubMed

    Anka-Lufford, Lukiana L; Huihui, Kierra M M; Gower, Nicholas J; Ackerman, Laura K G; Weix, Daniel J

    2016-08-01

    Cross-electrophile coupling of aryl halides with alkyl halides has thus far been primarily conducted with stoichiometric metallic reductants in amide solvents. This report demonstrates that the use of tetrakis(dimethylamino)ethylene (TDAE) as an organic reductant enables the use of non-amide solvents, such as acetonitrile or propylene oxide, for the coupling of benzyl chlorides and alkyl iodides with aryl halides. Furthermore, these conditions work for several electron-poor heterocycles that are easily reduced by manganese. Finally, we demonstrate that TDAE addition can be used as a control element to 'hold' a reaction without diminishing yield or catalyst activity. PMID:27273457

  13. Cacosmia and neurobehavioral dysfunction associated with occupational exposure to mixtures of organic solvents.

    PubMed

    Ryan, C M; Morrow, L A; Hodgson, M

    1988-11-01

    This study examined the interrelationships among occupational exposure to mixtures of organic solvents, neurobehavioral functioning, and complaints of cacosmia. The latter was defined as nausea, headaches, and subjective distress in individuals exposed to neutral environmental odors. The authors administered a battery of cognitive tests to men with and without a history of solvent exposure and found exposed workers to be impaired across a wide range of cognitive domains. Multiple regression analyses of exposed workers demonstrated a highly significant relationship between a history of cacosmia and performance decrements on measures of learning and memory. PMID:3189606

  14. Emission of volatile organic compounds to the atmosphere in the solvent sublation process. I. Toulene

    SciTech Connect

    Ososkov, V.; Kebbekus, B.; Mei Chen

    1996-01-01

    The mass of volatile organic compounds emitted to the atmosphere during solvent sublation was determined experimentally, using toluene as a test compound. It is shown that the emission of toluene to the atmosphere can be significantly reduced by using solvent sublation instead of air stripping under the same experimental conditions. The parameters which affect emission are the air flow rate, the nature and thickness of the organic layer, and the nature and concentrations of the co-solutes. Emissions are reduced as the thickness of the organic layer on the top of the column is increased. The use of decyl alcohol as the layer compound decreases emission to a greater extent than does paraffin oil. The emission of toluene during solvent sublation is further reduced as the air flow rate is lowered. The rate of toluene removal from water in solvent sublation is somewhat higher than in air stripping under the same experimental conditions. The effect of added anionic or cationic surfactants or alcohol was to improve the efficiency of water separation, but it also allowed more of the toluene to be emitted from the system.

  15. Application of a statistically enhanced, novel, organic solvent stable lipase from Bacillus safensis DVL-43.

    PubMed

    Kumar, Davender; Parshad, Rajinder; Gupta, Vijay Kumar

    2014-05-01

    This paper presents the molecular identification of a newly isolated bacterial strain producing a novel and organic solvent stable lipase, statistical optimization of fermentation medium, and its application in the synthesis of ethyl laurate. On the basis of nucleotide homology and phylogenetic analysis of 16S rDNA sequence, the strain was identified as Bacillus safensis DVL-43 (Gen-bank accession number KC156603). Optimization of fermentation medium using Plackett-Burman design and response surface methodology led to 11.4-fold increase in lipase production. The lipase from B. safensis DVL-43 exhibited excellent stability in various organic solvents. The enzyme retained 100% activity after 24h incubation in xylene, DMSO and toluene, each solvent being used at a concentration of 25% (v/v). The use of partially purified DVL-43 lipase as catalyst in the synthesis of ethyl laurate, an esterification product of lauric acid and ethanol, resulted in 80% esterification in 12h under optimized conditions. The formation of ethyl laurate was confirmed using TLC and (1)H NMR. Organic solvent stable lipases exhibiting potential application in enzymatic esterification are in great demand in flavor, fine chemicals and pharma industries. We could not find any report on lipase production from B. safensis strain and its application in esterification.

  16. Lipophilic polyelectrolyte gels as super-absorbent polymers for nonpolar organic solvents

    NASA Astrophysics Data System (ADS)

    Ono, Toshikazu; Sugimoto, Takahiro; Shinkai, Seiji; Sada, Kazuki

    2007-06-01

    Polyelectrolyte gels that are known as super-absorbent polymers swell and absorb water up to several hundred times their dried weights and have become ubiquitous and indispensable materials in many applications. Their superior swelling abilities originate from the electrostatic repulsion between the charges on the polymer chains and the osmotic imbalance between the interior and exterior of the gels. However, no super-absorbent polymers for volatile organic compounds (VOCs), and especially for nonpolar organic solvents (ɛ<10) have been reported, because common polyelectrolyte gels collapse in such solvents owing to the formation of a higher number of aggregates of ions and ion pairs. Here, we report that a novel class of polyelectrolyte gels bearing tetra-alkylammonium tetraphenylborate as a lipophilic and bulky ionic group swell in some nonpolar organic solvents up to 500 times their dry size. Dissociation of the ionic groups even in low-dielectric media (3<ɛ<10) enhances the swelling ability by expansion of the polymer networks. This expands the potential of polyelectrolytes that have been used only in aqueous solutions or highly polar solvents, and provides soft materials that swell in a variety of media. These materials could find applications as protective barriers for VOCs spilled in the environment and as absorbents for waste oil.

  17. Application of a statistically enhanced, novel, organic solvent stable lipase from Bacillus safensis DVL-43.

    PubMed

    Kumar, Davender; Parshad, Rajinder; Gupta, Vijay Kumar

    2014-05-01

    This paper presents the molecular identification of a newly isolated bacterial strain producing a novel and organic solvent stable lipase, statistical optimization of fermentation medium, and its application in the synthesis of ethyl laurate. On the basis of nucleotide homology and phylogenetic analysis of 16S rDNA sequence, the strain was identified as Bacillus safensis DVL-43 (Gen-bank accession number KC156603). Optimization of fermentation medium using Plackett-Burman design and response surface methodology led to 11.4-fold increase in lipase production. The lipase from B. safensis DVL-43 exhibited excellent stability in various organic solvents. The enzyme retained 100% activity after 24h incubation in xylene, DMSO and toluene, each solvent being used at a concentration of 25% (v/v). The use of partially purified DVL-43 lipase as catalyst in the synthesis of ethyl laurate, an esterification product of lauric acid and ethanol, resulted in 80% esterification in 12h under optimized conditions. The formation of ethyl laurate was confirmed using TLC and (1)H NMR. Organic solvent stable lipases exhibiting potential application in enzymatic esterification are in great demand in flavor, fine chemicals and pharma industries. We could not find any report on lipase production from B. safensis strain and its application in esterification. PMID:24534493

  18. Solvent dependence of Stokes shift for organic solute-solvent systems: A comparative study by spectroscopy and reference interaction-site model-self-consistent-field theory.

    PubMed

    Nishiyama, Katsura; Watanabe, Yasuhiro; Yoshida, Norio; Hirata, Fumio

    2013-09-01

    The Stokes shift magnitudes for coumarin 153 (C153) in 13 organic solvents with various polarities have been determined by means of steady-state spectroscopy and reference interaction-site model-self-consistent-field (RISM-SCF) theory. RISM-SCF calculations have reproduced experimental results fairly well, including individual solvent characteristics. It is empirically known that in some solvents, larger Stokes shift magnitudes are detected than anticipated on the basis of the solvent relative permittivity, ɛr. In practice, 1,4-dioxane (ɛr = 2.21) provides almost identical Stokes shift magnitudes to that of tetrahydrofuran (THF, ɛr = 7.58), for C153 and other typical organic solutes. In this work, RISM-SCF theory has been used to estimate the energetics of C153-solvent systems involved in the absorption and fluorescence processes. The Stokes shift magnitudes estimated by RISM-SCF theory are ∼5 kJ mol(-1) (400 cm(-1)) less than those determined by spectroscopy; however, the results obtained are still adequate for dipole moment comparisons, in a qualitative sense. We have also calculated the solute-solvent site-site radial distributions by this theory. It is shown that solvation structures with respect to the C-O-C framework, which is common to dioxane and THF, in the near vicinity (∼0.4 nm) of specific solute sites can largely account for their similar Stokes shift magnitudes. In previous works, such solute-solvent short-range interactions have been explained in terms of the higher-order multipole moments of the solvents. Our present study shows that along with the short-range interactions that contribute most significantly to the energetics, long-range electrostatic interactions are also important. Such long-range interactions are effective up to 2 nm from the solute site, as in the case of a typical polar solvent, acetonitrile.

  19. Solvent dependence of Stokes shift for organic solute-solvent systems: A comparative study by spectroscopy and reference interaction-site model-self-consistent-field theory

    NASA Astrophysics Data System (ADS)

    Nishiyama, Katsura; Watanabe, Yasuhiro; Yoshida, Norio; Hirata, Fumio

    2013-09-01

    The Stokes shift magnitudes for coumarin 153 (C153) in 13 organic solvents with various polarities have been determined by means of steady-state spectroscopy and reference interaction-site model-self-consistent-field (RISM-SCF) theory. RISM-SCF calculations have reproduced experimental results fairly well, including individual solvent characteristics. It is empirically known that in some solvents, larger Stokes shift magnitudes are detected than anticipated on the basis of the solvent relative permittivity, ɛr. In practice, 1,4-dioxane (ɛr = 2.21) provides almost identical Stokes shift magnitudes to that of tetrahydrofuran (THF, ɛr = 7.58), for C153 and other typical organic solutes. In this work, RISM-SCF theory has been used to estimate the energetics of C153-solvent systems involved in the absorption and fluorescence processes. The Stokes shift magnitudes estimated by RISM-SCF theory are ˜5 kJ mol-1 (400 cm-1) less than those determined by spectroscopy; however, the results obtained are still adequate for dipole moment comparisons, in a qualitative sense. We have also calculated the solute-solvent site-site radial distributions by this theory. It is shown that solvation structures with respect to the C-O-C framework, which is common to dioxane and THF, in the near vicinity (˜0.4 nm) of specific solute sites can largely account for their similar Stokes shift magnitudes. In previous works, such solute-solvent short-range interactions have been explained in terms of the higher-order multipole moments of the solvents. Our present study shows that along with the short-range interactions that contribute most significantly to the energetics, long-range electrostatic interactions are also important. Such long-range interactions are effective up to 2 nm from the solute site, as in the case of a typical polar solvent, acetonitrile.

  20. Synthesis of aspartame precursor with an immobilized thermolysin in mixed organic solvents.

    PubMed

    Miyanaga, M; Tanaka, T; Sakiyama, T; Nakanishi, K

    1995-06-20

    N-(benzyloxycarbonyl)-L-aspartyl-L-phenylalanine methyl ester, a precursor of the synthetic sweetener, aspartame, was synthesized from N-(benzyloxycarbonyl)-L-aspartic acid and L-phenylalanine methyl ester with an immobilized thermolysin (EC 3.4.24.4) in the mixed organic solvent system of tert-amyl alcohol and ethyl acetate. A mixed solvent consisting of tert-amyl alcohol and ethyl acetate at a ratio of 33:67 (v/v) was found to be the most suitable with respect to synthetic rate and stability of the immobilized enzyme. The reaction continued to proceed quite successfully in a column reactor at 40 degrees C and at a space velocity of 3.6 h(-1) with a yield of 99%, using 40 mM Z-Asp and 200 mM PheOMe dissolved in the mixed solvent as the substrate. (c) 1995 John Wiley & Sons, Inc.

  1. 40 CFR Table 7 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Default Organic HAP Mass Fraction for Petroleum Solvent Groups a 7 Table 7 to Subpart KKKK of Part 63 Protection of Environment ENVIRONMENTAL... Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in...

  2. 40 CFR Table 7 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Default Organic HAP Mass Fraction for Petroleum Solvent Groups a 7 Table 7 to Subpart KKKK of Part 63 Protection of Environment ENVIRONMENTAL... Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in...

  3. 40 CFR Table 7 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Default Organic HAP Mass Fraction for Petroleum Solvent Groups a 7 Table 7 to Subpart KKKK of Part 63 Protection of Environment ENVIRONMENTAL... Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction values in...

  4. [Development of revolutionary enzymatic reactions in organic solvents with molecular display].

    PubMed

    Ueda, Mitsuyoshi

    2010-11-01

    We have seen increasing use of the term "White biotechnology". White biotechnology involves the use of microbial cells and enzymes in the production of bulk and fine chemicals such as amino acids and polymers. This generally results in cleaner processes with minimum waste generation and energy use. Most of the organic syntheses using enzymes are carried out in nearly anhydrous organic solvents or solvent-free media. Ionic liquids have more recently emerged as another nonaqueous media, which, in view of their low vapor pressure, are viewed as "green solvents". Organic solvents may alter the structure and activity of enzymes that usually function in an aqueous environment. One alternative is to immobilize the enzymes on solid supports to increase their function and stability in response to organic solvents or increased temperatures. Enzymes may be stabilized by chemical and physical processes. With chemical methods, enzymes are immobilized by strong covalent bonding, but changes in protein structure often result. In physical stabilization processes, the interactions between enzymes and solids usually are weaker, resulting in fewer changes in the enzyme's structure. Yeast cell surface engineering is an alternative approach that immobilizes enzymes on the yeast cell surface. Proteins are immobilized by using an outer shell cell-wall protein, the C-terminal half of alpha-agglutinin. Display of enzymes on the yeast cell surface has at least two advantages relative to other physical immobilization methods. First, the displayed enzymes can be readily produced in a standard fermentation. No further work is required to either purify or immobilize the enzymes. Second, enzyme displayed on the yeast cell surface can be modified directly by conventional genetic engineering, which enables error-prone PCR, DNA shuffling, and combinatorial mutagenesis to be used quickly and efficiently to create strains (whole-cell biocatalysts) with enhanced enzyme activity.

  5. Effect of some organic solvent-water mixtures composition on precipitated calcium carbonate in carbonation process

    NASA Astrophysics Data System (ADS)

    Konopacka-Łyskawa, Donata; Kościelska, Barbara; Karczewski, Jakub

    2015-05-01

    Precipitated calcium carbonate particles were obtained during carbonation of calcium hydroxide slurry with carbon dioxide. Aqueous solutions of isopropyl alcohol, n-butanol and glycerol were used as solvents. Concentration of organic additives in the reactive mixture was from 0% to 20% (vol). Precipitation process were performed in a stirred tank reactor equipped with gas distributor. Multimodal courses of particles size distribution were determined for produced CaCO3 particles. Calcium carbonate as calcite was precipitated in all experiments. The mean Sauter diameter of CaCO3 particles decreased when the concentration of all used organic additives increased. The amount of small particle fraction in the product increased with the increasing concentration of organic solvents. Similar physical properties of used liquid phase resulted in the similar characteristics of obtained particles.

  6. Enzymatic catalysis in organic solvents: Polyethylene glycol modified hydrogenase retains sulfhydrogenase activity in toluene

    SciTech Connect

    Woodward, C.A.; Kaufman, E.N.

    1996-11-05

    Naturally occurring enzymes may be modified by covalently attaching hydrophobic groups that render the enzyme soluble and active in organic solvents, and have the potential to greatly expand applications of enzymatic catalysis. The reduction of elemental sulfur to hydrogen sulfide by a hydrogenase isolated from Pyrococcus furiosus has been investigated as a model system for organic biocatalysis. While the native hydrogenase catalyzed the reduction of sulfur to H{sub 2}S in aqueous solution, no activity was observed when the aqueous solvent was replaced with anhydrous toluene. Hydrogenase modified with PEG p-nitrophenyl carbonate demonstrated its native biocatalytic ability in toluene when the reducing dye, benzyl viologen, was also present. Neither benzyl viologen or PEG p-nitrophenyl carbonate alone demonstrated reducing capability. PEG modified cellulase and benzyl viologen were also incapable of reducing sulfur to H{sub 2}S, indicating that the enzyme itself, and not the modification procedure, is responsible for the conversion in the nonpolar organic solvent. Sulfide production in toluene was tenfold higher than that produced in an aqueous system with equal enzyme activity, demonstrating the advantages of organic biocatalysis. Applications of bioprocessing in nonaqueous media are expected to provide significant advances in the areas of fossil fuels, renewable feedstocks, organic synthesis, and environmental control technology.

  7. Structure Characterization and Properties of Metal-Surfactant Complexes Dispersed in Organic Solvents.

    PubMed

    de la Iglesia, Pablo; Jaeger, Vance W; Xi, Yuyin; Pfaendtner, Jim; Pozzo, Lilo D

    2015-08-25

    This work describes the synthesis and characterization of metal-surfactant complexes. Dioctyl sulfosuccinate and dodecylbenzenesulfonate are associated with multivalent aluminum, iron, and vanadium ions using an ion exchange reaction. The metal complexes are dispersible in various organic solvents. In solvents with low polarity, the complexes form "inverse" macromolecular structures with multiple metal ions. In contrast, in alcohols, the complex size is reduced, showing a more disperse conformation. The metal and surfactant ions are still strongly bonded to each other in all the solvents probed. Small-angle X-ray and neutron scattering (SAXS and SANS) are used to characterize the structures. Simultaneous fitting of neutron and X-ray scattering spectra is performed in order to obtain an accurate description of the system. Scattering results are also validated by performing molecular dynamics (MD) simulations. The conductive and electrochemical properties of the complexes in solution are also evaluated. The dispersion of metal-organic complexes significantly increases electric conductivity, and some metal ions in the core of the complexes are shown to be electrochemically active in apolar solvents.

  8. Production, characterization, and application of an organic solvent-tolerant lipase present in active inclusion bodies.

    PubMed

    Li, Suxia; Lin, Kang; Pang, Huaiyu; Wu, Yixin; Xu, Jianhe

    2013-01-01

    An organic solvent-tolerant lipase from Serratia marcescens ECU1010 (rSML) was overproduced in Escherichia coli in an insoluble form. High concentrations of both biomass (50 g cell wet weight/L culture broth) and inclusion bodies (10.5 g/L) were obtained by applying a high-cell-density cultivation procedure. Activity assays indicated that the enzymatic activity of rSML reached 600 U/L. After treatment with isopropyl ether for 12 h, the maximum lipase activity reached 6,000 U/L. Scanning electron microscopy and Fourier transform infrared microspectroscopy revealed the activation mechanism of rSML in the presence of organic solvents. rSML was stable in broad ranges of temperatures and pH values, as well as in a series of organic solvents. Besides, rSML showed the best enantioselectivity for the kinetic resolution of (±)-trans-3-(4-methoxyphenyl)glycidic acid methyl ester. These features render the S. marcescens ECU1010 lipase attractive for biotechnological applications in the field of organic synthesis and pharmaceutical industry. PMID:23269633

  9. New lipophilic polyelectrolyte gels containing quaternary ammonium salt with superabsorbent capacity for organic solvents.

    PubMed

    Chen, Jian; Wang, Shuojue; Peng, Jing; Li, Jiuqiang; Zhai, Maolin

    2014-09-10

    Water and soil pollution by organic pollutants from petrochemical plants has become one of the major environmental problems in recent years. Lipophilic polyelectrolyte gels with ionic groups dissociable in nonpolar organic solvents show an enhanced swelling ability in a corresponding media attributed to the electrostatic repulsion and osmotic pressure provided by dissociated ionic groups. Here, we synthesized new lipophilic polyelectrolyte gels based on an easily available electrolyte monomer, methacryloxyethyl dimethyloctane ammonium trifluoromethanesulfonimide (MODAT), and a lipophilic neutral monomer, dodecyl acrylate by radiation-induced polymerization and cross-linking. The resultant lipophilic polyelectrolyte gels could absorb plenty of organic solvents with dielectric constants lower than 20 and exhibited a high absorbing ability at a wide range of temperatures (0-40 °C). The maximum swelling degree could reach as high as 200 g/g in some media, such as 1,2-dichloroethane (199.4 g/g) and dichloromethane (204 g/g), which was much higher than that of the nonionic gel without the addition of MODAT. Moreover, the resultant lipophilic polyelectrolyte gels could release most of the absorbed solvents within several hours and then be reused. It is expected that this new type of lipophilic polyelectrolyte gels may be a suitable candidate as organic pollutant absorbents. PMID:25134413

  10. Y-Ba-Cu-O film deposition by metal organic chemical vapor deposition on buffered metal substrates.

    SciTech Connect

    Selvamanickam, V.; Galinski, G.; DeFrank, J.; Trautwein, C.; Haldar, P.; Balachandran, U.; Lanagan, M.; Chudzik, M.

    1999-10-12

    YBa{sub 2}Cu{sub 3}O{sub 2} (YBCO) films have been deposited on buffered metal substrates by Metal Organic Chemical Vapor Deposition (MOCVD). Cube-textured nickel substrates were fabricated by a thermomechanical process. Epitaxial CeO{sub 2}films were deposited on these substrates by thermal evaporation. Nickel alloy substrates with biaxially-textured Yttria-Stabilized Zirconia (YSZ) buffer layers deposited by Ion Beam Assisted Deposition were also prepared. Highly biaxially-textured YBCO films were deposited by MOCVD on both types of metal substrates. A critical current density greater than 10{sup 5} A/cm{sup 2} at 77 K has been achieved in YBCO films on metal substrates.

  11. Investigation of hole injection enhancement by MoO{sub 3} buffer layer in organic light emitting diodes

    SciTech Connect

    Haitao, Xu; Xiang, Zhou

    2013-12-28

    An MoO{sub 3} buffer layer prepared by thermal evaporation as hole injection layer was investigated in organic light emitting diodes. The MoO{sub 3} film inserted between the anode and hole transport layer decreased the operating voltage and enhanced power efficiency. Introduction of 1 nm MoO{sub 3} film, which was found to be the optimum layer thickness, resulted in 45% increase in efficiency compared with traditional ITO anode. Results from atomic force microscopy and photoemission spectroscopy showed that smooth surface morphology and suitable energy level alignment of ITO/MoO{sub 3} interface facilitated hole injection and transport. The hole injection and transport mechanism at the ITO/MoO{sub 3} interface in thin and thick buffer layers were analyzed.

  12. Singlet oxygen-sensitized delayed emissions from hydrogen peroxide/gallic acid/potassium ferricyanide systems containing organic solvents

    NASA Astrophysics Data System (ADS)

    Ishii, Hiroshi; Tsukino, Kazuo; Sekine, Masahiko; Nakata, Munetaka

    2009-06-01

    Fourier-transform chemiluminescence spectra of H 2O 2/gallic acid/K 3[Fe(CN) 6] systems containing organic solvents were measured. Emission bands with peaks around 530 and 700 nm were observed in systems containing solvents with a carbonyl group such as N, N-dimethylformamide, and those with a hydroxyl group such as methanol, respectively. The relative band intensities depended strongly on the concentration of these organic solvents. The emission species are attributed to gallic acid-ferricyanide complexes excited by energy transfer from singlet oxygen dimol, ( 1O 2) 2. The effects of organic solvents are interpreted in terms of intermolecular interactions of gallic acid-ferricyanide complexes, water molecules and organic solvents.

  13. Isolation of an organic solvent-tolerant bacterium Bacillus licheniformis PAL05 that is able to secrete solvent-stable lipase.

    PubMed

    Anbu, Periasamy; Hur, Byung Ki

    2014-01-01

    In this study, seven lipase-producing bacterial strains were isolated from salt-enriched and cattle farm soil samples after incubation in toluene- and benzene-enriched media. One strain (PAL05) showed significantly greater lipase activity on spirit blue agar medium and stability in organic solvents. The positive strain (PAL05) was identified as Bacillus licheniformis by 16S rRNA gene sequencing. Lipase production was optimized in a medium containing glycerol as the carbon source and Tween 80 as an inducer (0.5% glycerol+0.5% Tween 80) at pH 8.0 and a temperature of 30 °C. In addition, the enzyme was moderately halotolerant as it exhibited increased activity in the presence of 2.5% NaCl. Optimized conditions increased the lipase production threefold. Crude lipase retained its activity for 14 days of incubation in the presence of various organic solvents at a level of 25% and 50%. The enzyme was stable at 25% in most solvents; some of the solvents such as hexane, benzene, and ethanol actually stimulated enzyme activity. The organic solvent stability of the lipase produced by the strain PAL05 enables the enzyme to be used as a potential biocatalyst for ester synthesis and other applications in nonaqueous conditions. PMID:24397298

  14. Graphene/polyester staple composite for the removal of oils and organic solvents

    NASA Astrophysics Data System (ADS)

    Wu, Ruihan; Yu, Baowei; Liu, Xiaoyang; Li, Hongliang; Bai, Yitong; Ming, Zhu; Chen, Lingyun; Yang, Sheng-Tao; Chang, Xue-Ling

    2016-06-01

    Spongy graphene has been widely applied in oil removal. However, spongy graphene is hardly applicable for crude oil removal, because the complexity and high viscosity of crude oil. Herein, we reported that graphene/polyester staple composite (GPSC) could be used for the removal of oils and organic solvents, in particular crude oil. Graphene oxide was in situ reduced in the presence of polyester staple by hydrazine hydrate to form GPSC. GPSC efficiently adsorbed oils and organic solvents with high adsorption capacities. Demonstrations of treating pure oils and those in simulated sea water by GPSC were successfully performed. Due to the loose structure, GPSC adsorbed crude oil quickly with an adsorption capacity of 52 g g‑1. During the regeneration, the adsorption capacity of GPSC retained around 78% of the initial capacity up to 9 cycles. The implication to the applications of GPSC in water remediation is discussed.

  15. A new organic solvent tolerant protease from Bacillus pumilus 115b.

    PubMed

    Rahman, Raja Noor Zaliha Raja Abd; Mahamad, Shalihah; Salleh, Abu Bakar; Basri, Mahiran

    2007-07-01

    Five out of the nine benzene-toulene-ethylbenzene-xylene (BTEX) tolerant bacteria that demonstrated high protease activity on skim milk agar were isolated. Among them, isolate 115b identified as Bacillus pumilus exhibited the highest protease production. The protease produced was stable in 25% (v/v) benzene and toluene and it was activated 1.7 and 2.5- fold by n-dodecane and n-tetradecane, respectively. The gene encoding the organic solvent tolerant protease was cloned and its nucleotide sequence determined. Sequence analysis revealed an open reading frame (ORF) of 1,149 bp that encoded a polypeptide of 383 amino acid residues. The polypeptide composed of 29 residues of signal peptide, a propeptide of 79 residues and a mature protein of 275 amino acids with a calculated molecular mass of 27,846 Da. This is the only report available to date on organic solvent tolerant protease from B. pumilus.

  16. Separation of lignocresol from eucalyptus lignocresol-cellulase complex using organic solvents.

    PubMed

    Nonaka, Hiroshi; Kobayashi, Ai; Funaoka, Masamitsu

    2013-09-01

    A functional lignin-based material, lignocresol, was synthesized from eucalyptus wood meal by using phase separation treatment with p-cresol and 72% sulfuric acid. Lignocresol physically adsorbs Trichoderma reesei cellulase and functions as an immobilized cellulase. Lignocresol-immobilized cellulase was treated with acetone or ethanol to separate the enzyme and its support. Most lignocresol was dissolved in organic solvents and then precipitated in diethyl ether. The recovery yield of lignocresol using acetone was 85% and that using ethanol was 72%, with very low or negligible residual cellulase. Lignocresol is an innovative recyclable enzyme support that can be easily separated using only organic solvents after deactivation of the immobilized enzyme. PMID:23835277

  17. [Determination of residual organic solvents and macroporous resin residues in Akebia saponin D].

    PubMed

    Wang, Qiao-han; Yang, Xiao-lin; Xiao, Wei; Wang, Zhen-zhong; Ding, Gang; Huang, Wen-zhe; Yang, Zhong-lin

    2015-05-01

    According to ICH, Chinese Pharmacopoeia and supplementary requirements on the separation and purification of herbal extract with macroporous adsorption resin by SFDA, hexane, acetidine, ethanol, benzene, methyl-benzene, o-xylene, m-xylene, p-xylene, styrene, diethyl-benzene and divinyl-benzene of residual organic solvents and macroporous resin residues in Akebia saponin D were determined by headspace capillary GC. Eleven residues in Akebia saponin D were completely separated on DB-wax column, with FID detector, high purity nitrogen as the carry gases. The calibration curves were in good linearity (0.999 2-0.999 7). The reproducibility was good (RSD < 10%). The average recoveries were 80.0% -110%. The detection limit of each component was far lower than the limit concentration. The method is simple, reproducible, and can be used to determine the residual organic solvents and macroporous resin residues in Akebia saponin D. PMID:26390656

  18. Graphene/polyester staple composite for the removal of oils and organic solvents

    NASA Astrophysics Data System (ADS)

    Wu, Ruihan; Yu, Baowei; Liu, Xiaoyang; Li, Hongliang; Bai, Yitong; Ming, Zhu; Chen, Lingyun; Yang, Sheng-Tao; Chang, Xue-Ling

    2016-06-01

    Spongy graphene has been widely applied in oil removal. However, spongy graphene is hardly applicable for crude oil removal, because the complexity and high viscosity of crude oil. Herein, we reported that graphene/polyester staple composite (GPSC) could be used for the removal of oils and organic solvents, in particular crude oil. Graphene oxide was in situ reduced in the presence of polyester staple by hydrazine hydrate to form GPSC. GPSC efficiently adsorbed oils and organic solvents with high adsorption capacities. Demonstrations of treating pure oils and those in simulated sea water by GPSC were successfully performed. Due to the loose structure, GPSC adsorbed crude oil quickly with an adsorption capacity of 52 g g-1. During the regeneration, the adsorption capacity of GPSC retained around 78% of the initial capacity up to 9 cycles. The implication to the applications of GPSC in water remediation is discussed.

  19. One-pot hydrothermal preparation of graphene sponge for the removal of oils and organic solvents

    NASA Astrophysics Data System (ADS)

    Wu, Ruihan; Yu, Baowei; Liu, Xiaoyang; Li, Hongliang; Wang, Weixuan; Chen, Lingyun; Bai, Yitong; Ming, Zhu; Yang, Sheng-Tao

    2016-01-01

    Graphene sponge (GS) has found applications in oil removal due to the hydrophobic nature of graphene sheets. Current hydrothermal preparations of GS use toxic reducing reagents, which might cause environmental pollution. In this study, we reported that graphene oxide (GO) could be hydrothermally reduced by glucose to form GS for the adsorption of oils and various organic solvents. Graphene sheets were reduced by glucose during the hydrothermal treatment and formed 3D porous structure. GS efficiently adsorbed organic solvents and oils with competitive adsorption capacities. GS was able to treat pollutants in pure liquid form and also in the simulated seawater. GS could be easily regenerated by evaporating or burning. After 10 cycles, the adsorption capacity still retained 77% by evaporating and 87% by burning. The implication to the applications of GS in water remediation is discussed.

  20. The extraction-flocculation re-refining lubricating oil process using ternary organic solvents

    SciTech Connect

    Martins, J.P.

    1997-09-01

    The disposal of waste lubricating oils in landfills and/or city sewers can be disastrous due to the possible contamination of soils and waterways. Waste lubricating oils may be re-refined with organic solvents that dissolve base oil and segregate the additives and solid particles. The present paper emphasizes the composition effect on the efficiency of a ternary solvent composed by n-hexane/20propanol/1-butanol. Using the ternary diagram of waste oil/basic organic component/polar compound containing 3 g/L KOH where the phase envelope and the curves of constant sludge removal are plotted, it is proposed the composition of 0.25 waste oil/0.35 n-hexane/0.40 polar compound (80% 2-propanol + 20% 1-butanol, with 3 g/L KOH) for the process. A contribution for the understanding of polymethacrylate flocculation supported on infrared spectra is given.

  1. Neuropathy in an artist exposed to organic solvents in paints: a case study.

    PubMed

    Moshe, Shlomo; Bitchatchi, Enrique; Goshen, Joshua; Attias, Joseph

    2002-01-01

    A 61-year-old artist in Israel had been painting for 30 years in his home studio. He had been healthy until he reached the age of 59.5 years, at which time he began complaining of weakness and paresthesia in both hands and legs. He also complained that he had difficulty concentrating, and his memory was impaired. His work was unusual in that he painted large posters (i.e., 2 x 3 m) with different mixtures of organic solvents, including toluene, xylene, benzene, methyl ethyl ketone, toluene diisocyanate, acetone, and thinner. He did not use any protective gloves and did not wear a mask. He was evaluated with several methods and was diagnosed as having peripheral and central neuropathy, including ototoxic hearing loss as a result of long exposures to organic solvents. The authors were unable to find any similar case report in the literature. PMID:12194157

  2. Organic compounds of different extractability in total solvent extracts from soils of contrasting water repellency

    NASA Astrophysics Data System (ADS)

    Atanassova, Irena; Doerr, Stefan H.

    2010-05-01

    Previous studies examining organic compounds that may cause water-repellent behaviour of soils have typically focussed on analysing only the lipophilic fraction of extracted material. This study aimed to provide a more comprehensive examination by applying single- and sequential-accelerated solvent extraction (ASE), separation and analysis by GC/MS of the total solvent extracts of three soils taken from under eucalypt vegetation with different levels of water repellency. Water repellency increased in all the soils after extraction with DCM:MeOH (95:5), but was eliminated with iso-propanol/ammonia (95:5). Quantities of major lipid compound classes varied between solvents and soils. Iso-propanol/ammonia (95:5) solvent released saccharides, glycerol, aromatic acids and other polar organic compounds, which were more abundant in fractionated extracts from the single extraction and the third step sequential ASE extraction, than in the extracts from the DCM:MeOH ASE solvent. Dominant compounds extracted from all soils were long-chain alkanols (>C22), palmitic acid, C29 alkane, β-sitosterol, terpenes, terpenoids and other polar compounds. The soil with smallest repellency lacked >C18 fatty acids and had smallest concentrations of alkanols (C26, C28 and C30) and alkanes (C29, C31), but a greater abundance of more complex polar compounds than the more repellent soils. We therefore speculate that the above compounds play an important role in determining the water repellency of the soils tested. The results suggest that one-stage and sequential ASE extractions with iso-propanol:ammonia and subsequent fractionation of extracts are a useful approach in providing a comprehensive assessment of the potential compounds involved in causing soil water repellency.

  3. A calorimetric study of energy conversion efficiency of a sonochemical reactor at 500 kHz for organic solvents.

    PubMed

    Toma, Maricela; Fukutomi, Satoshi; Asakura, Yoshiyuki; Koda, Shinobu

    2011-01-01

    It would seem that the economic viability is yet to be established for a great number of sonochemical processes, owning to their perfectible ultrasonic equipments. Industrial scale sonoreactors may become more important as a result of mastering the parameters with influence on their energy balance. This work related the solvent type to the energy efficiency as the first step of a complex study aiming to assess the energy balance of sonochemical reactors at 500 kHz. Quantitative measurements of ultrasonic power for water and 10 pure organic solvents were performed by calorimetry for a cylindrically shaped sonochemical reactor with a bottom mounted vibrating plate. It was found that the ultrasonic power is strongly related to the solvent, the energy conversion for organic liquids is half from that of water and there is a drop in energy efficiency for filling levels up to 250 mm organic solvents. Surface tension, viscosity and vapor pressure influence the energy conversion for organic solvents, but it is difficult explain these findings based on physical properties of solvents alone. The apparent intensity of the atomization process shows a good agreement with the experimentally determined values for energy conversion for water and the solvent group studied here. This study revealed that to attain the same ultrasonic power level, more electrical energy is need for organic solvents as compared to water. The energy balance equation has been defined based on these findings by considering an energy term for atomization. PMID:20655791

  4. Coacervate Core Micelles for the Dispersion and Stabilization of Organophosphate Hydrolase in Organic Solvents

    NASA Astrophysics Data System (ADS)

    Mills, Carolyn; Obermeyer, Allie; Dong, Xuehui; Olsen, Bradley D.

    Bulk organophosphate (OP) nerve agents are difficult to decontaminate on site and dangerous to transport. The organophosphate hydrolase (OPH) enzyme is an efficient catalyst for hydrolyzing, and thus decontaminating, these compounds, but suffers from poor stability in the hydrophobic bulk OP environment. Here, we exploit the complex coacervation phase separation phenomenon to form complex coacervate core micelles (C3Ms) that can protect this OPH enzyme under these conditions. Stable C3Ms form when mixing a charged-neutral block copolymer methyl-quaternized poly(4-vinylpyridine)-block-poly(oligo(ethylene glycol) methacrylate) (Qp4vp- b-POEGMA), a homopolymer poly(acrylic acid) (PAA), and OPH under a certain conditions. The C3Ms are then transferred into two organic solvents, ethanol and dimethyl methylphosphonate (DMMP), which is a good simulant for the physical properties of the OP compounds. The C3Ms retain their nanostructures in the organic solvents. The activity test of OPH indicates that the C3Ms successfully protect OPH activity in organic solvents.

  5. [Cloning and expression of organic solvent tolerant lipase gene from Staphylococcus saprophyticus M36].

    PubMed

    Tang, Yanchong; Lu, Yaping; Lü, Fengxia; Bie, Xiaomei; Guo, Yao; Lu, Zhaoxin

    2009-12-01

    Lipases are important biocatalysts that are widely used in food processing and bio-diesel production. However, organic solvents could inactivate some lipases during applications. Therefore, the efficient cloning and expression of the organic solvent-tolerant lipase is important to its application. In this work, we first found out an organic solvent-tolerant lipase from Staphylococcus saprophyticus M36 and amplified the 741 bp Lipase gene lip3 (GenBank Accession No. FJ979867), by PCR, which encoded a 31.6 kD polypeptide of 247 amino acid residues. But the lipase shared 83% identity with tentative lip3 gene of Staphylococcus saprophyticus (GenBank Accession No. AP008934). We connected the gene with expression vector pET-DsbA, transformed it into Escherichia coli BL21 (DE3), and obtained the recombinant pET-DsbA-lip3. With the induction by 0.4 mmol/L of isopropyl beta-D-thiogalactopyranoside at pH 8.0, OD600 1.0, 25 degrees C for 12 h, the lipase activity reached up to 25.8 U/mL. The lipase expressed was stable in the presence of methanol, n-hexane, and isooctane, n-heptane.

  6. Enhancement of the aspartame precursor synthetic activity of an organic solvent-stable protease.

    PubMed

    Ogino, Hiroyasu; Tsuchiyama, Shotaro; Yasuda, Masahiro; Doukyu, Noriyuki

    2010-03-01

    The PST-01 protease is highly stable and catalyzes the synthesis of the aspartame precursor with high reaction yields in the presence of organic solvents. However, the synthesis rate using the PST-01 protease was slower than that observed when thermolysin was used. Structural comparison of both enzymes showed particular amino acid differences near the active center. These few residue differences in the PST-01 protease were mutated to match those amino acid types found in thermolysin. The mutated PST-01 proteases at the 114th residue from tyrosine to phenylalanine showed enhancement of synthetic activity. This activity was found to be similar to thermolysin. In addition, mutating the residue in the PST-01 protease with arginine and serine showed more improvement of the activity. The mutant PST-01 protease should be more useful than thermolysin for the synthesis of the aspartame precursor, because this enzyme has higher stability and activity in the presence of organic solvents. The results show the potential of organic solvent-stable enzymes as industrial catalysts.

  7. A Robust and Cost-Effective Superhydrophobic Graphene Foam for Efficient Oil and Organic Solvent Recovery.

    PubMed

    Zhu, Haiguang; Chen, Dongyun; An, Wei; Li, Najun; Xu, Qingfeng; Li, Hua; He, Jinghui; Lu, Jianmei

    2015-10-21

    Water pollution caused by chemical reagent leaking, industrial wastewater discharging, and crude oil spills has raised global concerns on environmental sustainability, calling for high-performance absorbent materials for effective treatments. However, low-cost materials capable of effectively separating oils and organic solvents from water with a high adsorption capacity and good recyclability are rare on the market. Here, a cost-effective method is reported to fabricate high-performance graphene modified absorbents through the facile thermal reduction of graphene oxide on the skeletons of melamine foam. By integrating the high porosity, superior elasticity, and mechanical stability of raw sponge with the chemical stability and hydrophobicity of graphene sheets, the as-fabricated graphene foam not only possesses a rough and superhydrophobic surface, but also exhibits an excellent adsorption performance and extraordinary recyclability for various oils and organic solvents. It is worth mentioning that the superhydrophobic surface also endows the graphene foam with an excellent efficiency for oil/water separation. More importantly, the cost-effective fabrication method without involving expensive raw materials and sophisticated equipment permits a scale-up of the graphene foam for pollution disposal. All these features make the graphene foam an ideal candidate for removal and collection of oils and organic solvents from water. PMID:26265103

  8. Towards safer sodium-ion batteries via organic solvent/ionic liquid based hybrid electrolytes

    NASA Astrophysics Data System (ADS)

    Monti, Damien; Ponrouch, Alexandre; Palacín, M. Rosa; Johansson, Patrik

    2016-08-01

    Hybrid electrolytes aimed at application in sodium-ion batteries (SIB) consisting of an organic solvent mixture (EC:PC) and different ionic liquids (ILs); EMImTFSI, BMImTFSI, and Pyr13TFSI, and with the NaTFSI salt providing the Na+ charge carriers have here been extensively studied. The physico-chemical and electrochemical characterisation includes ionic conductivity, viscosity, density, cation coordination and solvation, various safety measures, and electrochemical stability window (ESW). Hybrid electrolytes with 10-50% of IL content were found to have ionic conductivities on par with comparable organic solvent based electrolytes, but with highly enhanced safety properties. A systematic Raman spectroscopy study of the cation coordination and solvation before and after electrolyte safety tests by ignition suggest that IL cations and TFSI remain stable when ignited while organic solvents are consumed. Finally, the solid electrolyte interphase (SEI) formed when using hybrid electrolytes has both better mechanical and electrochemical stability than the SEI derived from pure IL based electrolytes. For a half-cell with a hard carbon (HC) electrode and a hybrid electrolyte with a composition of 0.8 m NaTFSI in EC0.45:PC0.45:Pyr13TFSI0.10 encouraging results were obtained for IL based electrolytes - ca. 182 mAhg-1 at C/10 over 40 cycles.

  9. A Robust and Cost-Effective Superhydrophobic Graphene Foam for Efficient Oil and Organic Solvent Recovery.

    PubMed

    Zhu, Haiguang; Chen, Dongyun; An, Wei; Li, Najun; Xu, Qingfeng; Li, Hua; He, Jinghui; Lu, Jianmei

    2015-10-21

    Water pollution caused by chemical reagent leaking, industrial wastewater discharging, and crude oil spills has raised global concerns on environmental sustainability, calling for high-performance absorbent materials for effective treatments. However, low-cost materials capable of effectively separating oils and organic solvents from water with a high adsorption capacity and good recyclability are rare on the market. Here, a cost-effective method is reported to fabricate high-performance graphene modified absorbents through the facile thermal reduction of graphene oxide on the skeletons of melamine foam. By integrating the high porosity, superior elasticity, and mechanical stability of raw sponge with the chemical stability and hydrophobicity of graphene sheets, the as-fabricated graphene foam not only possesses a rough and superhydrophobic surface, but also exhibits an excellent adsorption performance and extraordinary recyclability for various oils and organic solvents. It is worth mentioning that the superhydrophobic surface also endows the graphene foam with an excellent efficiency for oil/water separation. More importantly, the cost-effective fabrication method without involving expensive raw materials and sophisticated equipment permits a scale-up of the graphene foam for pollution disposal. All these features make the graphene foam an ideal candidate for removal and collection of oils and organic solvents from water.

  10. Organic solvents as interferents in arsenic determination by hydride generation atomic absorption spectrometry with flame atomization

    NASA Astrophysics Data System (ADS)

    Karadjova, Irina B.; Lampugnani, Leonardo; Dědina, Jiri; D'Ulivo, Alessandro; Onor, Massimo; Tsalev, Dimiter L.

    2006-05-01

    Interference effects of various organic solvents miscible with water on arsenic determination by hydride generation atomic absorption spectrometry have been studied. Arsine was chemically generated in continuous flow hydride generation system and atomized by using a flame atomizer able to operate in two modes: miniature diffusion flame and flame-in-flame. The effects of experimental variables and atomization mode were investigated: tetrahydroborate and hydrochloric acid concentrations, argon, hydrogen and oxygen supply rates for the microflame, and the distance from the atomization region to the observation zone. The nature of the species formed in the flame due to the pyrolysis of organic solvent vapors entering the flame volume together with arsine is discussed. The observed signal depression in the presence of organic solvents has been mainly attributed to the atomization interference due to heterogeneous gas-solid reaction between the free arsenic atoms and finely dispersed carbon particles formed by carbon radicals recombination. The best tolerance to interferences was obtained by using flame-in-flame atomization (5-10 ml min - 1 of oxygen flow rate), together with higher argon and hydrogen supply rates and elevated observation heights.

  11. Towards safer sodium-ion batteries via organic solvent/ionic liquid based hybrid electrolytes

    NASA Astrophysics Data System (ADS)

    Monti, Damien; Ponrouch, Alexandre; Palacín, M. Rosa; Johansson, Patrik

    2016-08-01

    Hybrid electrolytes aimed at application in sodium-ion batteries (SIB) consisting of an organic solvent mixture (EC:PC) and different ionic liquids (ILs); EMImTFSI, BMImTFSI, and Pyr13TFSI, and with the NaTFSI salt providing the Na+ charge carriers have here been extensively studied. The physico-chemical and electrochemical characterisation includes ionic conductivity, viscosity, density, cation coordination and solvation, various safety measures, and electrochemical stability window (ESW). Hybrid electrolytes with 10-50% of IL content were found to have ionic conductivities on par with comparable organic solvent based electrolytes, but with highly enhanced safety properties. A systematic Raman spectroscopy study of the cation coordination and solvation before and after electrolyte safety tests by ignition suggest that IL cations and TFSI remain stable when ignited while organic solvents are consumed. Finally, the solid electrolyte interphase (SEI) formed when using hybrid electrolytes has both better mechanical and electrochemical stability than the SEI derived from pure IL based electrolytes. For a half-cell with a hard carbon (HC) electrode and a hybrid electrolyte with a composition of 0.8 m NaTFSI in EC0.45:PC0.45:Pyr13TFSI0.10 encouraging results were obtained for IL based electrolytes - ca. 182 mAhg-1 at C/10 over 40 cycles.

  12. The Mammary Gland Carcinogens: The Role of Metal Compounds and Organic Solvents

    PubMed Central

    Mulware, Stephen Juma

    2013-01-01

    The increased rate of breast cancer incidences especially among postmenopausal women has been reported in recent decades. Despite the fact that women who inherited mutations in the BRCA1 and BRCA2 genes have a high risk of developing breast cancer, studies have also shown that significant exposure to certain metal compounds and organic solvents also increases the risks of mammary gland carcinogenesis. While physiological properties govern the uptake, intracellular distribution, and binding of metal compounds, their interaction with proteins seems to be the most relevant process for metal carcinogenicity than biding to DNA. The four most predominant mechanisms for metal carcinogenicity include (1) interference with cellular redox regulation and induction of oxidative stress, (2) inhibition of major DNA repair, (3) deregulation of cell proliferation, and (4) epigenetic inactivation of genes by DNA hypermethylation. On the other hand, most organic solvents are highly lipophilic and are biotransformed mainly in the liver and the kidney through a series of oxidative and reductive reactions, some of which result in bioactivation. The breast physiology, notably the parenchyma, is embedded in a fat depot capable of storing lipophilic xenobiotics. This paper reviews the role of metal compounds and organic solvents in breast cancer development. PMID:23762568

  13. Nanoparticle surface modification by amphiphilic polymers in aqueous media: role of polar organic solvents.

    PubMed

    Sarkar, Biswajit; Venugopal, Vinithra; Bodratti, Andrew M; Tsianou, Marina; Alexandridis, Paschalis

    2013-05-01

    We investigate the role of three polar organic solvents (dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), and glycerol) on the interfacial behavior of Pluronic P105 poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers on protonated silica nanoparticles in an aqueous dispersion. The polymer adsorption and self-assembly have been assessed from critical surface micelle concentration (csmc, measured by pyrene fluorescence spectroscopy) and adsorbed layer thickness (measured by capillary viscometry) data. Above its csmc, PEO-PPO-PEO block copolymers form hydrophobic domains on the nanoparticle surface. Below a critical concentration in water (known as critical displacer concentration, cdc), organic solvents act as displacers (molecules that can displace adsorbed polymer from a solid surface). The critical displacer concentration is obtained from the csmc and the polymer adsorbed layer thickness data. The cdc is found to be dependent on both the amount of nanoparticles present in the system as well as the nature of the displacer. Below the cdc, the csmc increases and the adsorbed polymer layer thickness decreases with increasing organic solvent concentration. Interfacial free energy calculations suggest that DMF, DMSO, and glycerol can adsorb onto the silica particles by displacing adsorbed PEO. These calculations are consistent with the experimental results in that, as a displacer, glycerol is the most effective and DMF is the least effective. Above the cdc, the influence of glycerol or DMSO on csmc is opposite to that of DMF which is attributed to the cosolvent effect.

  14. Is the general conclusion justified that higher applicable field strength results in shorter analysis time with organic solvents in CE?

    PubMed

    Téllez, Adolfo; Kenndler, Ernst

    2009-11-01

    In this paper, a widespread opinion in CE with organic solvents for the background electrolyte is critically questioned, namely that in general a shorter analysis time can be achieved due to the higher field strength applicable compared with aqueous electrolyte systems. This view, common in the literature, is based on the supposition that the conductance in organic solvents is lower than in water. Indeed in many organic solvents with higher viscosity than water lower ion mobility is observed, and higher fields can be applied in these cases. However, in this paper the problem is sharper defined and treated two-fold: (i) in all solvents conditions are such that either the same electric power is generated, or (ii) the same temperature increase is taken into account. It was shown that for the same electric power the field strength in the organic solvent can be changed to a less extent than the ionic mobility changes. As a result, the migration velocity of the analytes is lower and the analysis time is longer in most organic solvents compared with water; acetonitrile (MeCN) is an exception (in this solvent the mobilities are higher than in water). The more stringent treatment of the problem takes an equal temperature increase due to Joule heating into account rather than equal electric power. The temperature increase in the capillary depends on the thermal conductivity of the solvent, which is only about one-third of that of water for organic liquids. The consequence is that in none of the organic solvent systems a shorter analysis time can be achieved compared with water (given that the experimental conditions are comparable, e.g. zero EOF). The theoretical predictions were confirmed by measurements with water, methanol, propylenecarbonate, and MeCN as solvents.

  15. Carbon, hydrogen and nitrogen isotopes in solvent-extractable organic matter from carbonaceous chondrites

    NASA Technical Reports Server (NTRS)

    Becker, R. H.; Epstein, S.

    1982-01-01

    CCl4 and CH3OH solvent extractions were performed on the Murray, Murchison, Orgueil and Renazzo carbonaceous chondrites. Delta-D values of +300-+500% are found in the case of the CH3OH-soluble organic matter. The combined C, H and N isotope data makes it unlikely that the CH3OH-soluble components are derivable from, or simply related to, the insoluble organic polymer found in the same meteorites. A relation between the event that formed hydrous minerals in CI1 and CM2 meteorites and the introduction of water- and methanol-soluble organic compounds is suggested. Organic matter soluble in CCl4 has no N, and delta-C-13 values are lower than for CH3OH-soluble phases. It is concluded that there either are large isotopic fractionations for carbon and hydrogen between different soluble organic phases, or the less polar components are partially of terrestrial origin.

  16. [Liver function of workers occupationally exposed to mixed organic solvents in a petrochemical industry].

    PubMed

    Fernández-D'Pool, J; Oroño-Osorio, A

    2001-06-01

    A descriptive and cross sectional study was conducted to determine whether hepatic function changes in workers occupationally exposed to a mixture of organic solvents, were due to the exposure or confusing factors. A non random sample of 77 workers, operators and supervisors of the Olefin Plant I and II of a petrochemical industry in Maracaibo, Venezuela, was used. Their mean age was 29 +/- 7 years, and had at least one year of exposure to the solvents. This sample was compared with a group of employees of the administrative offices or control panel workers, with a mean age of 36 +/- 8 year and with similar anthropometric characteristics. Workers with a known history of liver disease, blood transfusions and diabetes mellitus were excluded of the study. In addition to a complete occupational disease medical history and a physical examination, serum samples were obtained to determine the activity of the aspartato aminotransferase (AST), alanin aminotransferase (ALT), gamma glutamiltransferase (GGT), alkaline phosphatase (AF), the concentration of the total bile acids (BAS), the surface antigen of hepatitis B(HbsAg) and the hepatitis A virus antibodies: AntiHAV-IgG and the AntiHAV-IgM. An urine sample was taken and analyzed by standard methodology to determine urinary phenols. The air concentrations of benzene, ethylbenzene, toluene and xylene were analyzed by gas chromathography. The serum activities of the liver enzymes, the concentration of bile acids and urinary phenols were not influenced by the exposure to the solvents. The increase of the activity of GGT was associated with obesity and alcohol consumption. The antibodies of the surface antigen of hepatitis A-IgM were normal in both groups and the antibodies for the antigen of hepatitis A-IgG presented a prevalence of 6% in the exposed group and 9% in the non exposed not being associated with liver abnormalities. The individual air concentrations of the solvents were below the environmentally permissible

  17. MEASUREMENT OF ENTRAINED ORGANIC DROPLET SIZES AND TOTAL CONCENTRATION FOR AQUEOUS STREAMS FROM THE CAUSTIC-SIDE SOLVENT EXTRACTION PROCESS

    SciTech Connect

    Nash, C; Samuel Fink, S; Michael Restivo, M; Dan Burns, D; Wallace Smith, W; S Crump, S; Zane Nelson, Z; Thomas Peters, T; Fernando Fondeur, F; Michael Norato, M

    2007-02-01

    The Modular Caustic-Side Solvent Extraction Unit (MCU) and the Salt Waste Processing Facility will remove radioactive cesium from Savannah River Site supernate wastes using an organic solvent system. Both designs include decanters and coalescers to reduce carryover of organic solvent droplets. Savannah River National Laboratory personnel conducted experimental demonstrations using a series of four 2-cm centrifugal contactors. They also examined organic carryover during operation of a CINC (Costner Industries Nevada Corporation) V-5 contactor under prototypical conditions covering the range of expected MCU operation. This report details the findings from those studies and the implications on design for the MCU.

  18. 40 CFR Table 4 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Petroleum Solvent Groups a 4 Table 4 to Subpart PPPP of Part 63 Protection of Environment ENVIRONMENTAL... 63—Default Organic HAP Mass Fraction for Petroleum Solvent Groups a You may use the mass fraction... Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha,...

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

    ERIC Educational Resources Information Center

    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…

  20. 40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... organic HAP content of aluminum wipedown solvents and aluminum recreational boat surface coatings? 63.5753...) National Emission Standards for Hazardous Air Pollutants for Boat Manufacturing Standards for Aluminum... aluminum wipedown solvents and aluminum recreational boat surface coatings? (a) Use equation 1 of...

  1. 40 CFR 63.5749 - How do I calculate the organic HAP content of aluminum wipedown solvents?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... content of aluminum wipedown solvents? 63.5749 Section 63.5749 Protection of Environment ENVIRONMENTAL... Boat Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5749 How do I calculate the organic HAP content of aluminum wipedown solvents? (a) Use equation 1 of...

  2. 40 CFR 63.5749 - How do I calculate the organic HAP content of aluminum wipedown solvents?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... content of aluminum wipedown solvents? 63.5749 Section 63.5749 Protection of Environment ENVIRONMENTAL... Boat Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5749 How do I calculate the organic HAP content of aluminum wipedown solvents? (a) Use equation 1 of...

  3. 40 CFR 63.5749 - How do I calculate the organic HAP content of aluminum wipedown solvents?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... content of aluminum wipedown solvents? 63.5749 Section 63.5749 Protection of Environment ENVIRONMENTAL... Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5749 How do I calculate the organic HAP content of aluminum wipedown solvents? (a) Use equation 1 of this section to...

  4. 40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... organic HAP content of aluminum wipedown solvents and aluminum recreational boat surface coatings? 63.5753...) National Emission Standards for Hazardous Air Pollutants for Boat Manufacturing Standards for Aluminum... aluminum wipedown solvents and aluminum recreational boat surface coatings? (a) Use equation 1 of...

  5. 40 CFR 63.5749 - How do I calculate the organic HAP content of aluminum wipedown solvents?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... content of aluminum wipedown solvents? 63.5749 Section 63.5749 Protection of Environment ENVIRONMENTAL... Boat Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5749 How do I calculate the organic HAP content of aluminum wipedown solvents? (a) Use equation 1 of...

  6. 40 CFR 63.5749 - How do I calculate the organic HAP content of aluminum wipedown solvents?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... content of aluminum wipedown solvents? 63.5749 Section 63.5749 Protection of Environment ENVIRONMENTAL... Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5749 How do I calculate the organic HAP content of aluminum wipedown solvents? (a) Use equation 1 of this section to...

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

    PubMed

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

    PubMed

    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. PMID:26658672

  9. An organic-solvent-tolerant esterase from thermophilic Bacillus licheniformis S-86.

    PubMed

    Torres, Sebastián; Martínez, M Alejandra; Pandey, Ashok; Castro, Guillermo R

    2009-01-01

    A thermophile, halotolerant and organic-solvent-tolerant esterase producer Bacillus sp. S-86 strain previously isolated was found to belong to Bacillus licheniformis species through morphological, biochemical, 16S rRNA gene sequence analyses and rDNA intergenic spacers amplification (ITS-PCR). The strain can grow at 55 degrees C in presence of C2-C7 alkanols (log P=-0.86 to 2.39), and NaCl concentrations up to 15% (w/v). This bacterium showed optimal growth and esterase production at 50 degrees C. Two different molecular weight esterase activities were detected in zymographic assays. PMSF inhibited type I esterase activity, showing no inhibitory effect on type II esterase activity. B. licheniformis S-86 was able to grow in presence of hydroxylic organic-solvents like propan-2-ol, butan-1-ol and 3-methylbutan-1-ol. At a sub-lethal concentration of these solvents (392 mmoll(-1) propan-2-ol; 99 mmol l(-1) butan-1-ol, 37 mmol l(-1) 3-methylbutan-1-ol), adequate to produce 50% cell growth inhibition at 50 degrees C, an increment between 1.9 and 2.3 times was observed in type I esterase production, and between 2.2 and 3.1 times in type II esterase production. PMID:18723341

  10. Impact of several water-miscible organic solvents on sorption of benzoic acid by soil

    SciTech Connect

    Lee, L.S.; Rao, P.S.C.

    1996-05-01

    Sorption of benzoic acid by a surface soil was measured from several binary mixtures of water and various organic cosolvents spanning a wide range in solvent properties. For all solvents investigated, the addition to an aqueous solution resulted in an increase in solubility and an alkaline shift in the conditional ionization constant (pK{sub a}{sup c}) of benzoic acid. Sorption data were assessed using a cosolvency model that incorporated speciation of the organic acid as determined by the pK{sub a}{sup c} and soil-solution pH. The model provided reasonable predictions of the sorption trends observed from acetone/water, acetonitrile/ water, and 1,4-dioxane/water solutions. However, enhanced sorption observed from DMSO/water solutions was not well described by the cosolvency model similar to what was previously observed for the sorption of carboxylic acids from methanol/water solutions. The relative importance of cosolvent properties and various solvent-specific mechanisms is discussed. Hydrogen bonding along with preferential solvation are hypothesized as the primary mechanisms responsible for the observed deviations from the model. 36 refs., 5 figs., 1 tab.

  11. Morphology of Organically-Modified Layered Silicates (ols) in Binary Solvents: Model System for Polymer Nanocomposites

    NASA Astrophysics Data System (ADS)

    Vaia, Richard; Farmer, Barry; Lui, Weidong; Bharadwaj, Rishi

    2001-03-01

    Critical to forwarding nanocomposite technology is development of a detailed understanding of the spatial distribution of the various constituents (inorganic, polymeric and additives) and associated influence on thermodynamic and kinetic (rheological) aspects of the system. With regard to these issues, in-situ small angle x-ray scattering, associated scattering models, coarse grain simulations, and rheology have been used to examine the phase behavior of organically modified layered silicates (OLS) suspended in pure and binary solvent mixtures. These serve as model systems for examining aspects of morphology development and phase behavior in thermoset and thermoplastic nanocomposites. The phase structure of solvent - OLS system is qualitatively described by Onsager arguments modified to include a crystal-solvate (intercalated phase) and a gelation point. Ternary behavior (binary solvent mixtures) provides evidence for preferential segregation of the polar component to the inorganic surface. The chemical structure of the organic surfactant modifier has a negligible influence on the structure of the intercalated phase, but has a marked effect on the extent and concentration of the dispersed phase. These studies provide insight into the use of polar activators for organosilicate rheolgical control agents and additives to enhance nanocomposite formation (e.g. H20 addition for optimal exfoliated PDMS nanocomposites and incorporation of malic anhydride to produce polypropylene nanocomposites).

  12. Implementation of a solvent management program to control paint shop volatile organic compounds

    SciTech Connect

    Floer, M.M.; Hicks, B.H.

    1997-12-31

    The majority of automobile assembly plant volatile organic compound (VOC) emissions are generated from painting operations. Typical paint operations generate more than 90 percent of the total plant emissions and, up to, 50 percent can be released by cleaning sources. Plant practices which contribute to the release of VOC emissions include the cleaning of paint lines and equipment, tanks, spray booths, floors and vehicles. Solvents continue to be the largest contributing source of VOC emissions in an automotive paint shop. To reduce overall VOC emissions, environmental regulations and guidelines were introduced under the Clean Air Act; Pollution Prevention and Waste Minimization programs, Control Techniques, and special air permit conditions. The introduction of these regulations and guidelines has driven industry toward continual refinement of their present cleaning methods while pursuing new techniques and technologies. Industry has also shown a proactive approach by introducing new waterborne and powder coating paint technologies to reduce overall emissions. As new paint technologies are developed and introduced, special attention must be given to the types of materials utilized for cleaning. The development and implementation of a solvent management program allows a facility to standardize a program to properly implement materials, equipment, technologies and work practices to reduce volatile organic compound emissions, meet strict cleaning requirements posed by new paint technologies and produce a vehicle which meets the high quality standards of the customer. This paper will assess the effectiveness of a solvent management program by examining pollution prevention initiatives and data from four different painting operations.

  13. Nanocrystals self-assembled in superlattices directed by the solvent-organic capping interaction.

    PubMed

    Dalmaschio, Cleocir José; da Silveira Firmiano, Edney Geraldo; Pinheiro, Antonio Narcisio; Sobrinho, Diego Guedes; Farias de Moura, André; Leite, Edson Roberto

    2013-06-21

    Close-packed arrays of ZrO2 nanocrystals (NCs) have been self-assembled from a colloidal solution in a withdrawal dip coating process. A benzyl alcohol route was used to obtain NCs of narrowly controlled size, and then the capping layer was replaced by oleate using solvothermal treatment. The oleate solubility was explored in chloroform, hexane and toluene to prepare thin films of NCs using a dip coating process. From TEM images, the final structures show that increasing the solvent polarity improved self-assembly to prepare mono- and multi-layer superlattices, during solvent evaporation in a short time. The entangled organic chain in the NC surface offsets the limitations of the faceted NCs, improving the assembly quality, allowing the NC assembly to approach the formation of a hard sphere model, resulting in a FCC close-packed structure. Furthermore, the low interaction of chloroform with the capping layer reduces the shrinkage effect during the solvent evaporation preserving the array in the final self-assembled structure. Molecular dynamics simulations with soft potentials supported the conclusion that hexane interacts with the organic capping ligand, increasing the apparent radius of each NC and stabilizing the colloidal suspension, whereas chloroform is partially removed from the capping layer during the aggregation process, forming an array of nanoparticles. PMID:23685460

  14. Effect of organic solvents on peroxidases from rice and horseradish: prospects for enzyme based applications.

    PubMed

    Singh, Priyanka; Prakash, Rajiv; Shah, Kavita

    2012-08-15

    A feasibility test for rice peroxidase (RP) enzyme as a substitute for horseradish peroxidase (HRP) was carried out. The activity of HRP was maximum at 30 °C with pH 6.0-7.0. The purified rice peroxidase showed optimum activity at 30 °C with pH 7-8 and was thermostable till 68 °C, which is higher than the temperature reported for HRP. RP obeyed Michaelis-Menten kinetics. With increasing substrate concentrations, RP and HRP had V(max) as 8.23 μM min(-1) and 4.21 μM min(-1) and K(m) as 5.585 and 3.662 mM, respectively. In 10% 1,4-dioxane and ethanol, RP exhibited 2 and 1.3 times higher activity, respectively than HRP. Shelf life studies show RP to be significantly stable till 60 h in 20% 1,4-dioxane and till 12 h in ethanol. The activity of RP/HRP increased gradually with 0%-40% ethanol or 0%-30% 1,4-dioxane till 20 h with a sharp decline thereafter. The stability of HRP and RP reduced with increasing storage period. Enzyme efficiencies compared as V(m)/K(m) showed water miscible organic solvents, viz.1,4-dioxane and ethanol, to exhibit a regular decrease in V(m)/K(m) with increase in organic solvent concentration whereas, a reverse trend was observed with water-immiscible solvent like chloroform. The relative activity of RP and HRP enzymes upon immobilization on poly-5-carboxy-indole shows increasing enzyme activity with time and with guaiacol/dopamine hydrochloride as substrates. Immobilized RP had a better relative activity with dopamine as substrate than immobilized HRP, whereas with guaiacol both RP and HRP had a comparable activity upon immobilization. Results suggest rice peroxidase to be a cheaper and convenient enzyme system for immobilization using organic solvents. The high thermal stability, more stability in organic solvents and longer shelf life of RP over the immobilizing matrix suggest conducting polyindole having carboxyl functional groups to be a suitable matrix for the covalent entrapment of rice peroxidase through amide linkage. Good

  15. Production of an osteoinductive demineralised bone matrix powder without the use of organic solvents.

    PubMed

    Eagle, M J; Rooney, P; Kearney, J N

    2015-09-01

    Demineralised bone matrix (DBM) is produced by grinding cortical bone into a powder, sieving the powder to obtain a desired size range and then demineralising the powder using acid. Protocols for the production of DBM powder have been published since 1965 and the powder can be used in lyophilised form or it can be mixed with a carrier to produce a paste or putty. The powder is generally produced from cortical bone which has been processed to remove blood, bone marrow and bone marrow components, including fat. Removal of fat is accomplished by incorporating incubation in an organic solvent, often chloroform, chloroform/methanol or acetone. The use of organic solvents in a clean room environment in a human tissue bank is problematic and involves operator exposure and the potential for the solvent to be trapped in air filters or recirculated throughout the clean room suite. Consequently, in this study, we have developed a cortical bone washing step which removes fat/lipid without the use of an organic solvent. Bone was prepared from six femoral shafts from three donors by dissecting soft tissue and bisecting the shaft, the shafts were then cut into ~9-10 cm lengths. These struts were then taken through a series of hot water washes at 56-59 °C, centrifugation and decontamination steps. Washed cortical struts were then lyophilised before being ground with a compressed air milling machine. The ground bone was sieved, demineralised, freeze-dried and terminally sterilised with a target dose of 25 kGy gamma irradiation. The DBM powder was evaluated for residual calcium content, in vitro cytotoxicity and osteoinductivity by implantation into the muscle of an athymic mouse. Data indicated that in addition to removing in excess of 97% DNA and extractable soluble protein, the washing protocol reduced lipid 10,000-fold. The processed bone was easily ground without clogging the grinder; the sterilised DBM powder was not cytotoxic but was osteoinductive in the animal model

  16. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    DOEpatents

    Taylor, R.T.; Jackson, K.J.; Duba, A.G.; Chen, C.I.

    1998-05-19

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants are described. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating. 21 figs.

  17. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    DOEpatents

    Taylor, Robert T.; Jackson, Kenneth J.; Duba, Alfred G.; Chen, Ching-I

    1998-01-01

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating.

  18. Imaging Nanostructures by Single-Molecule Localization Microscopy in Organic Solvents.

    PubMed

    Aloi, Antonio; Vargas Jentzsch, Andreas; Vilanova, Neus; Albertazzi, Lorenzo; Meijer, E W; Voets, Ilja K

    2016-03-01

    The introduction of super-resolution fluorescence microscopy (SRM) opened an unprecedented vista into nanoscopic length scales, unveiling a new degree of complexity in biological systems in aqueous environments. Regrettably, supramolecular chemistry and material science benefited far less from these recent developments. Here we expand the scope of SRM to photoactivated localization microscopy (PALM) imaging of synthetic nanostructures that are highly dynamic in organic solvents. Furthermore, we characterize the photophysical properties of commonly used photoactivatable dyes in a wide range of solvents, which is made possible by the addition of a tiny amount of an alcohol. As proof-of-principle, we use PALM to image silica beads with radii close to Abbe's diffraction limit. Individual nanoparticles are readily identified and reliably sized in multicolor mixtures of large and small beads. We further use SRM to visualize nm-thin yet μm-long dynamic, supramolecular polymers, which are among the most challenging molecular systems to image. PMID:26885701

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

    SciTech Connect

    Thomas, Ajith; Elsa Tom, Anju; Ison, V. V. E-mail: praveen@materials.iisc.ernet.in; Rao, Arun D.; Varman, K. Arul; Ranjith, K.; Ramamurthy, Praveen C. E-mail: praveen@materials.iisc.ernet.in; Vinayakan, R.

    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.

  20. Exposure to organic solvents and neuropsychological dysfunction: a study on monozygotic twins.

    PubMed Central

    Hänninen, H; Antti-Poika, M; Juntunen, J; Koskenvuo, M

    1991-01-01

    Twenty one monozygotic twins exposed to organic solvents were compared with their non-exposed cotwins by performance in psychological tests. A further 28 monozygotic twin pairs were examined as a reference group. The study used 11 tests, 10 of which had shown an effect in previous studies on the results of exposure to solvents. Paired comparisons of the test scores showed the exposed twins to have lower performance in associative learning, digit span, and block design. These results agree with two previous studies that used a similar set of tests. Contrary to some other studies, psychomotor speed was not affected, but the results indicated a marginal effect on the control of hand movements. Further comparison of subgroups with a low and a high exposure showed the prevalence of subtle neuropsychological dysfunction to be greater among the more exposed twins. PMID:1993155

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

    PubMed

    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.

  2. Spray coating fabrication of organic solar cells bypassing the limit of orthogonal solvents

    NASA Astrophysics Data System (ADS)

    Colella, Silvia; Mazzeo, Marco; Melcarne, Giovanna; Carallo, Sonia; Ciccarella, Giuseppe; Gigli, Giuseppe

    2013-05-01

    The development of alternative deposition techniques is an important step towards the realization of low cost multilayered organic solar cells. While spin-coating needs orthogonal solvents to avoid an intermixing of stacked layers, thermal evaporation is expensive and not applicable to polymers. We show here how an innovative deposition technique called dry spray-coating may represent a promising way to manufacture bulk-hetero-junction (BHJ) and multilayered solar cells. Using standard materials such as poly(3-hexylthiophene-2,5-diyl) and [6,6]-phenyl-C61-butyric acid methyl ester, we achieved efficiency of 2.6% for the BHJ device, while a value of 1.5% was obtained for a bilayer structure using the same solvent for both materials.

  3. Permeation of Tank C-103 sludge simulant by organic solvent. Revision 1

    SciTech Connect

    Gerber, M.A.

    1995-08-01

    The plan for stabilizing underground storage tanks calls for draining the supernate from the tanks; however, there is concern that draining the supernate from Tank C-103 will degrade safety in the tank. The sludge in Tank C-103 contains ranges in depth from 1 to 1.5 m and is covered by both an aqueous phase and a separate organic layer. The main concern is that draining the supernate will cause the solvent to permeate the sludge solids and provide a source of fuel for a fire on the surface of the drained sludge. The question of whether the solvent will permeate sludge that is 1 to 1.5 m deep after the tank is dewatered is the purpose of the tests conducted and described in this report.

  4. Hydrothermal liquefaction of palm oil empty fruit bunch (EFB) into bio-oil in different organic solvents

    NASA Astrophysics Data System (ADS)

    Sarwono, Rakhman; Pusfitasari, Eka Dian; Ghozali, Muhammad

    2016-06-01

    Thermochemical Liquefaction of empty fruit bunch (EFB) of palm oil in different organic solvents (water, methanol, ethanol, acetone, toluene and hexane) were comparatively investigated. Experiments were carried out in an autoclave at different temperatures of 300, 350 and 400 °C with a fixed solid/liquid rasio of 3 gram in 50 ml solvent, without catalysts and reaction time of 5 hours. The efficiency of above solvents in terms of conversion rate, soluble liquid and carbon products were investigated in the experiments. Increasing the reaction temperature increased the conversion rate in all organic solvents and water, but gaseous products also increased using a reaction temperature of 400 oC. The water solvent gave higher conversion rate of 49.14%, while toluene, acetone, methanol, hexane and ethanol gave conversion of 35.76%, 26.5%, 25.98%, 24.26 %, and 22.24%, respectively. The bio-oil produced in order of the largest amount were using methanol, water, ethanol, toluene, acetone, and hexane solvents. The chemical properties of bio-oil products were significantly affected by the type of liquefaction solvent. The composition of bio-oil consisted of mostly of a mixture of organic acids, ketones, and esters. The methanol and ethanol solvents resulted in mostly esters, while toluene and hexane resulted in mostly organic acids. Acetone solvent resulted in the same amount of organic acid and esters. In water as a solvent resulted in 2-pentanone, 4-hydroxy-4-methyl. The bio-oil consisted of a range of carbon C6 - C20 fragments.

  5. Application of natural deep eutectic solvents to the extraction of anthocyanins from Catharanthus roseus with high extractability and stability replacing conventional organic solvents.

    PubMed

    Dai, Yuntao; Rozema, Evelien; Verpoorte, Robert; Choi, Young Hae

    2016-02-19

    Natural deep eutectic solvents (NADES) have attracted a great deal of attention in recent times as promising green media. They are generally composed of neutral, acidic or basic compounds that form liquids of high viscosity when mixed in certain molar ratio. Despite their potential, viscosity and acid or basic nature of some ingredients may affect the extraction capacity and stabilizing ability of the target compounds. To investigate these effects, extraction with a series of NADES was employed for the analysis of anthocyanins in flower petals of Catharanthus roseus in combination with HPLC-DAD-based metabolic profiling. Along with the extraction yields of anthocyanins their stability in NADES was also studied. Multivariate data analysis indicates that the lactic acid-glucose (LGH), and 1,2-propanediol-choline chloride (PCH) NADES present a similar extraction power for anthocyanins as conventional organic solvents. Furthermore, among the NADES employed, LGH exhibits an at least three times higher stabilizing capacity for cyanidins than acidified ethanol, which facilitates their extraction and analysis process. Comparing NADES to the conventional organic solvents, in addition to their reduced environmental impact, they proved to provide higher stability for anthocyanins, and therefore have a great potential as possible alternatives to those organic solvents in health related areas such as food, pharmaceuticals and cosmetics. PMID:26822320

  6. Complexes of a naphthalimide photoacid with organic bases, and their excited-state dynamics in polar aprotic organic solvents.

    PubMed

    Kumpulainen, Tatu; Bakker, Bert H; Brouwer, Albert M

    2015-08-28

    Complex formation and intermolecular excited-state proton transfer (ESPT) between a dihydroxy-1,8-naphthalimide photoacid and organic bases are investigated in polar aprotic solvents. First, quantum chemical calculations are used to explore the acid-base and spectroscopic properties and to identify energetically favorable complexes. The two hydroxyl groups of the photoacid enable stepwise formation of 1 : 1 and 1 : 2 complexes. Weak bases exhibit only hydrogen-bonding interactions whereas strong bases are able to deprotonate one of the hydroxyl groups resulting in strong negative cooperativity (K1≫ 4K2) in the formation of the 1 : 2 complex. Time-resolved fluorescence studies of the complexes provide strong indications of a three-step dissociation process. The species involved in the model are: a hydrogen-bonded complex, a hydrogen-bonded ion pair, a solvent separated ion pair, and a free ion pair. PMID:26204802

  7. Novel organic solvent-tolerant esterase isolated by metagenomics: insights into the lipase/esterase classification.

    PubMed

    Berlemont, Renaud; Spee, Olivier; Delsaute, Maud; Lara, Yannick; Schuldes, Jörg; Simon, Carola; Power, Pablo; Daniel, Rolf; Galleni, Moreno

    2013-01-01

    in order to isolate novel organic solvent-tolerant (OST) lipases, a metagenomic library was built using DNA derived from a temperate forest soil sample. A two-step activity-based screening allowed the isolation of a lipolytic clone active in the presence of organic solvents. Sequencing of the plasmid pRBest recovered from the positive clone revealed the presence of a putative lipase/esterase encoding gene. The deduced amino acid sequence (RBest1) contains the conserved lipolytic enzyme signature and is related to the previously described OST lipase from Lysinibacillus sphaericus 205y, which is the sole studied prokaryotic enzyme belonging to the 4.4 α/β hydrolase subgroup (abH04.04). Both in vivo and in vitro studies of the substrate specificity of RBest1, using triacylglycerols or nitrophenyl-esters, respectively, revealed that the enzyme is highly specific for butyrate (C4) compounds, behaving as an esterase rather than a lipase. The RBest1 esterase was purified and biochemically characterized. The optimal esterase activity was observed at pH 6.5 and at temperatures ranging from 38 to 45 °C. Enzymatic activity, determined by hydrolysis of p-nitrophenyl esters, was found to be affected by the presence of different miscible and non-miscible organic solvents, and salts. Noteworthy, RBest1 remains significantly active at high ionic strength. These findings suggest that RBest1 possesses the ability of OST enzymes to molecular adaptation in the presence of organic compounds and resistance of halophilic proteins.

  8. 40 CFR Table 3 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... None. 7. Aromatic 100 0.02 1% xylene, 1% cumene. 8. Aromatic 150 0.09 Naphthalene. 9. Aromatic naphtha 64742-95-6 0.02 1% xylene, 1% cumene. 10. Aromatic solvent 64742-94-5 0.1 Naphthalene. 11. Exempt....06 3% toluene, 3% xylene. 22. Petroleum distillate mixture 68477-31-6 0.08 4% naphthalene,...

  9. 40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... 7. Aromatic 100 2 1% xylene, 1% cumene. 8. Aromatic 150 9 Naphthalene. 9. Aromatic naptha 64742-95-6 2 1% xylene, 1% cumene. 10. Aromatic solvent 64742-94-5 10 Naphthalene. 11. Exempt mineral spirits.... Petroleum distillate mixture 68477-31-6 8 4% naphthalene, 4% biphenyl....

  10. 40 CFR Table 5 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Naphthalene. 9. Aromatic naphtha 64742-95-6 0.02 1% xylene, 1% cumene. 10. Aromatic solvent 64742-94-5 0.1 Naphthalene. 11. Exempt mineral spirits 8032-32-4 0 None. 12. Ligroines (VM & P) 8032-32-4 0 None. 13. Lactol...% naphthalene, 4% biphenyl....

  11. 40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... None. 7. Aromatic 100 2 1% xylene, 1% cumene. 8. Aromatic 150 9 Naphthalene. 9. Aromatic naptha 64742-95-6 2 1% xylene, 1% cumene. 10. Aromatic solvent 64742-94-5 10 Naphthalene. 11. Exempt mineral.... Petroleum distillate mixture 68477-31-6 8 4% naphthalene, 4% biphenyl....

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

    SciTech Connect

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

    1999-05-17

    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.

  13. Exposure to Organic Solvents Used in Dry Cleaning Reduces Low and High Level Visual Function

    PubMed Central

    Jiménez Barbosa, Ingrid Astrid

    2015-01-01

    Purpose 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). Methods 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. Results 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

  14. Heavy metals, organic solvents, and multiple sclerosis: An exploratory look at gene-environment interactions.

    PubMed

    Napier, Melanie D; Poole, Charles; Satten, Glen A; Ashley-Koch, Allison; Marrie, Ruth Ann; Williamson, Dhelia M

    2016-01-01

    Exposure to heavy metals and organic solvents are potential etiologic factors for multiple sclerosis (MS), but their interaction with MS-associated genes is under-studied. The authors explored the relationship between environmental exposure to lead, mercury, and solvents and 58 single-nucleotide polymorphisms (SNPs) in MS-associated genes. Data from a population-based case-control study of 217 prevalent MS cases and 496 age-, race-, gender-, and geographically matched controls were used to fit conditional logistic regression models of the association between the chemical, gene, and MS, adjusting for education and ancestry. MS cases were more likely than controls to report lead (odds ratio [OR] = 2.03; 95% confidence interval [CI]: 1.07, 3.86) and mercury exposure (OR = 2.06; 95% CI: 1.08, 3.91). Findings of potential gene-environment interactions between SNPs in TNF-α, TNF-β, TCA-β, VDR, MBP, and APOE, and lead, mercury, or solvents should be considered cautiously due to limited sample size.

  15. Transport, Targeting and Applications of Metallic Functional Nanoparticles for Degradation of DNAPL Chlorinated Organic Solvents

    SciTech Connect

    Lowry, Gregory V.; Majetich, Sara; Sholl, David; Tilton, Robert D.; Matyjaszewski, Krzysztof; Liu, Yueqiang; Sarbu, Traian; Almusallam, Abdulwahab; Redden, George D.; Meakin, Paul; Rollins, Harry W.

    2004-03-31

    Recently, laboratory and field studies have demonstrated that zero-valent iron nanoparticles (colloids) can rapidly transform dissolved chlorinated organic solvents into non-toxic compounds. This technology also has the potential to address Dense Non- Aqueous Phase Liquid (DNAPL) contamination, one of DOE's primary contamination problems. This project develops and tests polymer-modified reactive nanoscale Fe0 particles for in situ delivery to chlorinated solvents that are present as DNAPLs in the subsurface. The surfaces of reactive Fe0-based nanoparticles are modified with amphiphilic block copolymers to maintain a stable suspension of the particles in water for transport in a porous matrix and to create an affinity for the water-DNAPL interface. Ultimately this will provide an improved technology to locate and eliminate DNAPL, a recalcitrant and persistent source for groundwater contamination by chlorinated solvents. Candidate polymers have been synthesized and attached to 20 nm SiO2 particles using Atom Transfer Radical Polymerization (ATRP). The physical properties (hydrodynamic radius, stability, TCE-water partitioning behavior, mobility in a porous matrix) of these nanostructures have been determined. The particles (dp {approx}102 nm) are water soluble and partition to the TCE-water interface. The physical and chemical properties (e.g. oxide phase and thickness) of Fe0 nanoparticles synthesized using different techniques and the effects of these properties on particle reactivity and efficiency have been evaluated. Numerical models (Brownian Dynamics) have been developed to predict the aqueous diffusivities of these particle-polymer nanostructures.

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

    NASA Astrophysics Data System (ADS)

    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).

  17. Heavy metals, organic solvents and multiple sclerosis: an exploratory look at gene-environment interactions

    PubMed Central

    Napier, Melanie D.; Poole, Charles; Satten, Glen A.; Ashley-Koch, Allison; Marrie, Ruth Ann; Williamson, Dhelia M.

    2015-01-01

    Exposure to heavy metals and organic solvents are potential etiologic factors for multiple sclerosis (MS), but their interaction with MS-associated genes is under-studied. We explored the relationship between environmental exposure to lead, mercury, and solvents and 58 single nucleotide polymorphisms (SNPs) in MS-associated genes. Data from a population-based case-control study of 217 prevalent MS cases and 496 age-, race-, gender-, and geographically-matched controls were used to fit conditional logistic regression models of the association between the chemical, gene, and MS, adjusting for education and ancestry. MS cases were more likely than controls to report lead (odds ratio (OR)=2.03; 95% confidence interval (CI): 1.07, 3.86) and mercury exposure (OR=2.06; 95% CI: 1.08, 3.91). Findings of potential gene-environment interactions between SNPs in TNF-α, TNF-β, TCA-β, VDR, MBP, and APOE, and lead, mercury, or solvents should be considered cautiously due to limited sample size. PMID:25137520

  18. Experimental and Theoretical Study of Molecular Response of Amine Bases in Organic Solvents

    SciTech Connect

    Kathmann, Shawn M.; Cho, Herman M.; Chang, Tsun-Mei; Schenter, Gregory K.; Parab, Kshitij K.; Autrey, Thomas

    2014-05-08

    Reorientational correlation times of various amine bases (viz., pyridine, 2,6-lutidene, 2,2,6,6-tetramethylpiperidine) and organic solvents (dichloromethane, toluene) were determined by solution-state NMR relaxation time measurements and compared with predictions from molecular dynamics (MD) simulations. The bases and solvents are reagents in complex reactions involving Frustrated Lewis Pairs (FLP), which display remarkable catalytic activity in metal-free H2 scission. The comparison of measured and simulated correlation times is a key test of the ability of recent MD and quantum electronic structure calculations to elucidate the mechanism of FLP activity. Correla- tion times were found to be in the range 1.4-3.4 ps (NMR) and 1.23-5.28 ps (MD) for the amines, and 0.9-2.3 ps (NMR) and 0.2-1.7 ps (MD) for the solvent molecules. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences. Pacic Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle.

  19. Archaeal Inorganic Pyrophosphatase Displays Robust Activity under High-Salt Conditions and in Organic Solvents

    PubMed Central

    McMillan, Lana J.; Hepowit, Nathaniel L.

    2015-01-01

    Soluble inorganic pyrophosphatases (PPAs) that hydrolyze inorganic pyrophosphate (PPi) to orthophosphate (Pi) are commonly used to accelerate and detect biosynthetic reactions that generate PPi as a by-product. Current PPAs are inactivated by high salt concentrations and organic solvents, which limits the extent of their use. Here we report a class A type PPA of the haloarchaeon Haloferax volcanii (HvPPA) that is thermostable and displays robust PPi-hydrolyzing activity under conditions of 25% (vol/vol) organic solvent and salt concentrations from 25 mM to 3 M. HvPPA was purified to homogeneity as a homohexamer by a rapid two-step method and was found to display non-Michaelis-Menten kinetics with a Vmax of 465 U · mg−1 for PPi hydrolysis (optimal at 42°C and pH 8.5) and Hill coefficients that indicated cooperative binding to PPi and Mg2+. Similarly to other class A type PPAs, HvPPA was inhibited by sodium fluoride; however, hierarchical clustering and three-dimensional (3D) homology modeling revealed HvPPA to be distinct in structure from characterized PPAs. In particular, HvPPA was highly negative in surface charge, which explained its extreme resistance to organic solvents. To demonstrate that HvPPA could drive thermodynamically unfavorable reactions to completion under conditions of reduced water activity, a novel coupled assay was developed; HvPPA hydrolyzed the PPi by-product generated in 2 M NaCl by UbaA (a “salt-loving” noncanonical E1 enzyme that adenylates ubiquitin-like proteins in the presence of ATP). Overall, we demonstrate HvPPA to be useful for hydrolyzing PPi under conditions of reduced water activity that are a hurdle to current PPA-based technologies. PMID:26546423

  20. Isolation and characterization of a novel thermophilic-organic solvent stable lipase from Acinetobacter baylyi.

    PubMed

    Uttatree, Sasithorn; Winayanuwattikun, Pakorn; Charoenpanich, Jittima

    2010-11-01

    The benzene tolerant Acinetobacter baylyi isolated from marine sludge in Angsila, Thailand could constitutively secrete lipolytic enzymes. The enzyme was successfully purified 21.89-fold to homogeneity by ammonium sulfate precipitation and gel-permeable column chromatography with a relative molecular mass as 30 kDa. The enzyme expressed maximum activity at 60 degrees C and pH 8.0 with p-nitrophenyl palmitate as a substrate and found to be stable in pH and temperature ranging from 6.0-9.0 to 60-80 degrees C, respectively. A study on solvent stability revealed that the enzyme was highly resisted to many organic solvents especially benzene and isoamyl alcohol, but 40% inhibited by decane, hexane, acetonitrile, and short-chain alcohols. Lipase activity was completely inhibited in the presence of Fe(2+), Mn(2+), EDTA, SDS, and Triton X-100 while it was suffered detrimentally by Tween 80. The activity was enhanced by phenylmethylsulfonyl fluoride (PMSF), Na(+), and Mg(2+) and no significant effect was found in the presence of Ca(2+) and Li(+). Half of an activity was retained by Ba(2+), Ag(+), Hg(+), Ni(2+), Zn(2+), and DTT. The enzyme could hydrolyze a wide range of p-nitrophenyl esters, but preferentially medium length acyl chains (C(8)-C(12)). Among natural oils and fats, the enzyme 11-folds favorably catalyzed the hydrolysis of rice bran oil, corn oil, sesame oil, and coconut oil in comparison to palm oil. Moreover, the transesterification activity of palm oil to fatty acid methyl esters (FAMEs) revealed 31.64 +/- 1.58% after 48 h. The characteristics of novel A. baylyi lipase, as high temperature stability, organic solvent tolerance, and transesterification capacity from palm oil to FAMEs, indicate that it could be a vigorous biocatalyzer in the prospective fields as bioenergy industry or even in organic synthesis and pharmaceutical industry. PMID:20177822

  1. Self-diffusion coefficients for water and organic solvents at high temperatures along the coexistence curve

    NASA Astrophysics Data System (ADS)

    Yoshida, Ken; Matubayasi, Nobuyuki; Nakahara, Masaru

    2008-12-01

    The self-diffusion coefficients D for water, benzene, and cyclohexane are determined by using the pulsed-field-gradient spin echo method in high-temperature conditions along the liquid branch of the coexistence curve: 30-350 °C (1.0-0.58 g cm-3), 30-250 °C (0.87-0.56 g cm-3), and 30-250 °C (0.77-0.48 g cm-3) for water, benzene, and cyclohexane, respectively. The temperature and density effects are separated and their origins are discussed by examining the diffusion data over a wide range of thermodynamic states. The temperature dependence of the self-diffusion coefficient for water is larger than that for organic solvents due to the large contribution of the attractive hydrogen-bonding interaction in water. The density dependence is larger for organic solvents than for water. The difference is explained in terms of the van der Waals picture that the structure of nonpolar organic solvents is determined by the packing effect due to the repulsion or exclusion volumes. The dynamic solvation shell scheme [K. Yoshida et al., J. Chem. Phys. 127, 174509 (2007)] is applied for the molecular interpretation of the translational dynamics with the aid of molecular dynamics simulation. In water at high temperatures, the velocity relaxation is not completed before the relaxation of the solvation shell (mobile-shell type) as a result of the breakdown of the hydrogen-bonding network. In contrast, the velocity relaxation of benzene is rather confined within the solvation shell (in-shell type).

  2. Supercritical fluid extraction and organic solvent microextraction of chemical agent simulants from soil

    SciTech Connect

    Griest, W.H.; Ramsey, R.S.; Ho, C.h.; Caldwell, W.M.

    1991-12-31

    Experiments with chemical warfare agent simulants suggest that supercritical fluid extraction can achieve good extraction recoveries of agents in soil and produce less laboratory waste than current organic solvent extraction methods. Two-ppm spikes in 1 g of Rocky Mountain Arsenal Standard Soil were extracted using 5% methanol in carbon dioxide at 300 atm for 2 min at 60{degrees}C. Recoveries (n=3) were 79{plus_minus}23% for dimethylmethylphosphonate, 93{plus_minus}14% for 2-chlorethylethylsulfide, 92{plus_minus}13% for diisopropylfluorophosphate, and 95{plus_minus}17% for diisopropylmethylphosphonate. A 5 min ultrasonic micro-scale extraction using methanol is more reproducible but less efficient.

  3. Supercritical fluid extraction and organic solvent microextraction of chemical agent simulants from soil

    SciTech Connect

    Griest, W.H.; Ramsey, R.S.; Ho, C.h.; Caldwell, W.M.

    1991-01-01

    Experiments with chemical warfare agent simulants suggest that supercritical fluid extraction can achieve good extraction recoveries of agents in soil and produce less laboratory waste than current organic solvent extraction methods. Two-ppm spikes in 1 g of Rocky Mountain Arsenal Standard Soil were extracted using 5% methanol in carbon dioxide at 300 atm for 2 min at 60{degrees}C. Recoveries (n=3) were 79{plus minus}23% for dimethylmethylphosphonate, 93{plus minus}14% for 2-chlorethylethylsulfide, 92{plus minus}13% for diisopropylfluorophosphate, and 95{plus minus}17% for diisopropylmethylphosphonate. A 5 min ultrasonic micro-scale extraction using methanol is more reproducible but less efficient.

  4. Activity and Enantioselectivity of the Hydroxynitrile Lyase MeHNL in Dry Organic Solvents

    PubMed Central

    Paravidino, Monica; Sorgedrager, Menno J; Orru, Romano V A; Hanefeld, Ulf

    2010-01-01

    Water concentration affects both the enantioselectivity and activity of enzymes in dry organic media. Its influence has been investigated using the hydrocyanation of benzaldehyde catalyzed by hydroxynitrile lyase cross-linked enzyme aggregate (MeHNL-CLEA) as a model reaction. The enzyme displayed higher enantioselectivity at higher water concentration, thus suggesting a positive effect of enzyme flexibility on selectivity. The activity increased on reducing the solvent water content, but drastic dehydration of the enzyme resulted in a reversible loss of activity. PMID:20486110

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Study of the resolution of amino acids and aminoalcohols in organic solvents.

    PubMed

    Orsini, F; Pelizzoni, F; Ghioni, C

    1995-06-01

    The enzymatic resolution of racemic phenylglycine, phenylglycinol and phenylalaninol has been studied in organic solvents under a variety of experimental conditions. Subtilisin in 3-methyl-3-pentanol was effective for the resolution of phenylglycine esters, via N-acylation with trifluoroethyl butyrate. Porcine pancreatic lipase in ethyl acetate gave satisfactory results in the resolution of phenylglycinol and phenylalaninol; theα orβ position of the phenyl group was found to influence both the rate and the chemioselectivity of the reaction. PMID:24178813

  7. Limitations and feasibility of the land disposal of organic solvent-contaminated wastes

    USGS Publications Warehouse

    Roy, W.R.; Griffin, R.A.; Mitchell, J.K.; Mitchell, R.A.

    1989-01-01

    The limitations and feasibility of the land disposal of solid wastes containing inorganic solvents and refrigerants (chlorinated fluorocarbons) were investigated by evaluating the attenuation capacity of a hypothetical waste-disposal site by numerical modeling. The basic theorem of this approach was that the land disposal wastes would be environmentally acceptable if subsurface attenuation reduced groundwater concentrations of organic compounds to concentrations that were less than health-based, water-quality criteria. Computer simulations indicated that the predicted concentrations of 13 of 33 organic compounds in groundwater would be less than their health-based criteria. Hence, solid wastes containing these compounds could be safely disposed at the site. The attenuation capacity of the site was insufficient to reduce concentrations of four compounds to safe levels without limiting the amount of mass available to leach into groundwater. Threshold masses based on time-dependent migration simulations were estimated for these compounds. The remaining 16 compounds, which consisted mainly of chlorinated hydrocarbons and fluorocarbons could not be safely landfilled without severe restrictions on the amounts disposed. These organic compounds were candidates to ban from land disposal.The limitations and feasibility of the land disposal of solid wastes containing organic solvents and refrigerants (chlorinated fluorocarbons) were investigated by evaluating the attenuation capacity of a hypothetical waste-disposal site by numerical mdoeling. Computer simulations indicated that the predicted concentrations of 13 of 33 organic compounds in groundwater would be less than their health-based criteria. Hence, solid wastes containing these compounds could be safely disposed at the site. The attenuation capacity of the site was insufficient to reduce concentrations of four compounds to safe levels without limiting the amount of mass available to leach into groundwater. The

  8. Improved solvent collection system for a dispersive liquid-liquid microextraction of organochlorine pesticides from water using low-density organic solvent.

    PubMed

    Chang, Chu-Chi; Wei, Shuo-Yang; Huang, Shang-Da

    2011-04-01

    In this study, the organochlorine pesticides (OCPs) levels in lake and tap water samples were determined by a dispersive liquid-liquid microextraction method using a low-density organic solvent and an improved solvent collection system (DLLME-ISCS). This method used a very small volume of a solvent of low toxicity (11  μL of 1-nonanol and 400  μL of methanol) to extract OCPs from 10  mL water samples prior to the analysis by GC. After centrifugation in the dispersive liquid-liquid microextraction, there was a liquid organic drop floating between the water surface and the glass wall of the centrifuge tube. The liquid organic drop (with some water phase) was transferred into a microtube (3  mm×15  mm) with a syringe. The organic and aqueous phases were separated in the microtube immediately. Then, 1  μL of the organic solvent (which was in the upper portion of liquid in the microtube) was easily collected by a syringe and injected into the GC-ECD system for the analysis. Under optimum conditions, the linear range of this method was 5-5000  ng/L for most of the analytes. The correlation coefficient was higher than 0.997. Enrichment factors ranged from 1309 to 3629. The relative recoveries ranged from 73 to 119% for lake water samples. The LODs of the method ranged from 0.7 to 9.4  ng/L. The precision of the method ranged from 1.0 to 10.8% for lake water.

  9. High-performance hybrid buffer layer using 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile/molybdenum oxide in inverted top-emitting organic light-emitting diodes.

    PubMed

    Park, Cheol Hwee; Lee, Hyun Jun; Hwang, Ju Hyun; Kim, Kyu Nyun; Shim, Yong Sub; Jung, Sun-Gyu; Park, Chan Hyuk; Park, Young Wook; Ju, Byeong-Kwon

    2015-03-25

    A high-performance 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HATCN)/molybdenum oxide (MoO3) hybrid buffer layer with high hole-injection efficiency and superior plasma resistance under the sputtering process was developed. The HATCN enhances the hole-injection efficiency, and the MoO3 effectively protects the underlying organic layers from plasma damage during deposition by sputtering. This improves the characteristics of inverted top-emitting organic light-emitting diodes using a top transparent conductive oxide electrode. The device using the hybrid buffer layer showed the highest electroluminescence characteristics among devices with other buffer layers. The high hole-injection efficiency of HATCN was shown by the J-F curve of hole-only devices, and the plasma protection performance of MoO3 was shown by atomic force microscope surface morphology images of the buffer layer film after O2 plasma treatment.

  10. Highly mesoporous metal–organic framework assembled in a switchable solvent

    PubMed Central

    Peng, Li; Zhang, Jianling; Xue, Zhimin; Han, Buxing; Sang, Xinxin; Liu, Chengcheng; Yang, Guanying

    2014-01-01

    The mesoporous metal–organic frameworks are a family of materials that have pore sizes ranging from 2 to 50 nm, which have shown promising applications in catalysis, adsorption, chemical sensing and so on. The preparation of mesoporous metal–organic frameworks usually needs the supramolecular or cooperative template strategy. Here we report the template-free assembly of mesoporous metal–organic frameworks by using CO2-expanded liquids as switchable solvents. The mesocellular metal–organic frameworks with large mesopores (13–23 nm) are formed, and their porosity properties can be easily adjusted by controlling CO2 pressure. Moreover, the use of CO2 can accelerate the reaction for metal–organic framework formation from metal salt and organic linker due to the viscosity-lowering effect of CO2, and the product can be recovered through CO2 extraction. The as-synthesized mesocellular metal–organic frameworks are highly active in catalysing the aerobic oxidation of benzylic alcohols under mild temperature at atmospheric pressure. PMID:25047059

  11. Photodegradation of moxifloxacin in aqueous and organic solvents: a kinetic study.

    PubMed

    Ahmad, Iqbal; Bano, Raheela; Musharraf, Syed Ghulam; Ahmed, Sofia; Sheraz, Muhammad Ali; ul Arfeen, Qamar; Bhatti, Muhammad Salman; Shad, Zufi

    2014-12-01

    The kinetics of photodegradation of moxifloxacin (MF) in aqueous solution (pH 2.0-12.0), and organic solvents has been studied. MF photodegradation is a specific acid-base catalyzed reaction and follows first-order kinetics. The apparent first-order rate constants (kobs) for the photodegradation of MF range from 0.69 × 10(-4) (pH 7.5) to 19.50 × 10(-4) min(-1) (pH 12.0), and in organic solvents from 1.24 × 10(-4) (1-butanol) to 2.04 × 10(-4) min(-1) (acetonitrile). The second-order rate constant (k2) for the [H(+)]-catalyzed and [OH(-)]-catalyzed reactions are 6.61 × 10(-2) and 19.20 × 10(-2) M(-1) min(-1), respectively. This indicates that the specific base-catalyzed reaction is about three-fold faster than that of the specific acid-catalyzed reaction probably as a result of the rapid cleavage of diazabicyclononane side chain in the molecule. The kobs-pH profile for the degradation reactions is a V-shaped curve indicating specific acid-base catalysis. The minimum rate of photodegradation at pH 7-8 is due to the presence of zwitterionic species. There is a linear relation between kobs and the dielectric constant and an inverse relation between kobs and the viscosity of the solvent. Some photodegraded products of MF have been identified and pathways proposed for their formation in acid and alkaline solutions.

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

    Code of Federal Regulations, 2010 CFR

    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...

  13. Assessment of two immobilized lipases activity and stability to low temperatures in organic solvents under ultrasound-assisted irradiation.

    PubMed

    Batistella, Luciane; Ustra, Mara K; Richetti, Aline; Pergher, Sibele B C; Treichel, Helen; Oliveira, J V; Lerin, Lindomar; de Oliveira, Débora

    2012-03-01

    Both stability and catalytic activity of two commercial immobilized lipases were investigated in the presence of different organic solvents in ultrasound-assisted system. In a general way, for Novozym 435, the use of ethanol as solvent led to a loss of activity of 35% after 10 h of contact. The use of iso-octane conducted to a gradual increase in lipase activity in relation to the contact time, reaching a maximum value of relative activity of 126%. For Lipozyme RM IM, after 5 h of exposure, the enzyme presented no residual activity when ethanol was used as solvent. The solvents tert-butanol and iso-octane showed an enhancement of about 20 and 17% in the enzyme activity in 6 h of exposure, respectively. Novozym 435 and Lipozyme IM presented high stability to storage after treatment under ultrasound-assisted system using n-hexane and tert-butanol as solvents.

  14. Assessment of two immobilized lipases activity and stability to low temperatures in organic solvents under ultrasound-assisted irradiation.

    PubMed

    Batistella, Luciane; Ustra, Mara K; Richetti, Aline; Pergher, Sibele B C; Treichel, Helen; Oliveira, J V; Lerin, Lindomar; de Oliveira, Débora

    2012-03-01

    Both stability and catalytic activity of two commercial immobilized lipases were investigated in the presence of different organic solvents in ultrasound-assisted system. In a general way, for Novozym 435, the use of ethanol as solvent led to a loss of activity of 35% after 10 h of contact. The use of iso-octane conducted to a gradual increase in lipase activity in relation to the contact time, reaching a maximum value of relative activity of 126%. For Lipozyme RM IM, after 5 h of exposure, the enzyme presented no residual activity when ethanol was used as solvent. The solvents tert-butanol and iso-octane showed an enhancement of about 20 and 17% in the enzyme activity in 6 h of exposure, respectively. Novozym 435 and Lipozyme IM presented high stability to storage after treatment under ultrasound-assisted system using n-hexane and tert-butanol as solvents. PMID:21779888

  15. Ideal p-n Diode Current Equation for Organic Heterojunction using a Buffer Layer: Derivation and Numerical Study

    NASA Astrophysics Data System (ADS)

    Kim, SeongMin; Ha, Jaewook; Kim, Jin-Baek

    2016-04-01

    The equation of p-n diode current-voltage (J-V) of an organic heterojunction (HJ) including a hole and electron buffer layer is derived, and its characteristics are numerically simulated based on a polaron-pair model Giebink et al. (Forrest, Phys. Rev. B 82; 1-12, 2010). In particular, the correlation between a fraction of the potential drop for an electron/hole buffer ( δ e - b / δ h - b ) and for a donor (D)/acceptor (A) ( δ D / δ A ) is numerically investigated for J-V curves. As a result, the lowest diode current (DC) is obtained for the condition of δ e - b + δ A ≅ 0 or δ D + δ h - b ≅ 1. It is suggested that it is important to characterize the lowest DC curve for the state of D/A blending with a condition of a fraction of the potential drop ( δ e - b / δ h - b ). Under these circumstances, the transport of holes ( h +) from a DC source at the reverse bias is effectively limited.

  16. Evaluation of different approaches to quantify strong organic acidity and acid-base buffering of organic-rich surface waters in Sweden.

    PubMed

    Köhler, Stephan; Hruska, Jakub; Jönsson, Jörgen; Lövgren, Lars; Lofts, Stephen

    2002-11-01

    The role of organic acids in buffering pH in surface waters has been studied using a small brownwater stream (26mg L(-1) TOC) draining a forested catchment in Northern Sweden. Under the conditions of elevated pressure of CO2 stream field pH was changed between 3.5 and 6.1 during the acidification and alkalinization experiment. Acid-base characteristics of the natural organic matter were also determined using a high precision potentiometric method for a concentrated sample from the same stream. We compared the predictions from the Windermere Humic Aqueous Model (WHAM Model V), a model derived from the potentiometric titration (diprotic/monoprotic acid model) and a previously derived triprotic acid model which only uses alkalinity and TOC as input variables. The predicted buffering characteristics of all three models are very similar in the pH range 4.5-7 which suggests that during routine analysis alkalinity and TOC are sufficient to give a good estimate of organic acid anion charge contribution in a large range of surface waters. A slightly adjusted version of WHAM V successfully describes the organic charge contribution in a large number of sampled surface water lakes, which were previously used to calibrate the triprotic model.

  17. Enantioselective hydrolysis of epichlorohydrin using whole Aspergillus niger ZJB-09173 cells in organic solvents.

    PubMed

    Jin, Huo-Xi; Hu, Zhong-Ce; Zheng, Yu-Guo

    2012-09-01

    The enantioselective hydrolysis of racemic epichlorohydrin for the production of enantiopure (S)-epichlorohydrin using whole cells of Aspergillus niger ZJB-09173 in organic solvents was investigated. Cyclohexane was used as the reaction medium based on the excellent enantioselectivity of epoxide hydrolase from A. niger ZJB- 09173 in cyclohexane. However, cyclohexane had a negative effect on the stability of epoxide hydrolase from A. niger ZJB-09173. In the cyclohexane medium, substrate inhibition, rather than product inhibition of catalysis, was observed in the hydrolysis of racemic epichlorohydrin using A. niger ZJB-09173. The racemic epichlorohydrin concentration was markedly increased by continuous feeding of substrate without significant decline of the yield. Ultimately, 18.5% of (S)-epichlorohydrin with 98 percent enantiomeric excess from 153.6 mM of racemic epichlorohydrin was obtained by the dry cells of A. niger ZJB-09173, which was the highest substrate concentration in the production of enantiopure (S)-epichlorohydrin by epoxide hydrolases using an organic solvent medium among the known reports. PMID:22922194

  18. Metal biosorption capacity of the organic solvent tolerant Pseudomonas fluorescens TEM08.

    PubMed

    Uzel, Atac; Ozdemir, Guven

    2009-01-01

    Many kinds of biomass are being tested as a biosorption material for metal removal from the contaminated waters. In the present study the biosorption capacity of an organic solvent tolerant (OST) bacterium was investigated against Cr(VI) and Ni(II). The OST strain of Pseudomonas fluorescens TEM08 was isolated from an oil contaminated soil sample and grown in normal culture conditions (type I) and in the presence of the cyclohexane (type II). Two types of cells were used in the biosorption experiments to compare the organic solvent effect on the biosorption capacity. The biosorption equilibrium was described by Langmuir and Freundlich adsorption isotherms. The value of Q(0) was higher for type I cells (40.8 for Cr(VI); 12.4 for Ni(II)) then the type II (40.7 for Cr(VI); 11.2 for Ni(II)). The adsorption capacity constants (K(F)) of Freundlich model for type I cells and for type II cells were 10.87 and 8.78 for Ni(II) and 13.60 and 10.99 for Cr(VI), respectively. PMID:18657416

  19. Response of Rhodococcus erythropolis strain IBBPo1 to toxic organic solvents.

    PubMed

    Stancu, Mihaela Marilena

    2015-01-01

    Recently, there has been a lot of interest in the utilization of rhodococci in the bioremediation of petroleum contaminated environments. This study investigates the response of Rhodococcus erythropolis IBBPo1 cells to 1% organic solvents (alkanes, aromatics). A combination of microbiology, biochemical, and molecular approaches were used to examine cell adaptation mechanisms likely to be pursued by this strain after 1% organic solvent exposure. R. erythropolis IBBPo1 was found to utilize 1% alkanes (cyclohexane, n-hexane, n-decane) and aromatics (toluene, styrene, ethylbenzene) as the sole carbon source. Modifications in cell viability, cell morphology, membrane permeability, lipid profile, carotenoid pigments profile and 16S rRNA gene were revealed in R. erythropolis IBBPo1 cells grown 1 and 24 h on minimal medium in the presence of 1% alkanes (cyclohexane, n-hexane, n-decane) and aromatics (toluene, styrene, ethylbenzene). Due to its environmental origin and its metabolic potential, R. erythropolis IBBPo1 is an excellent candidate for the bioremediation of soils contaminated with crude oils and other toxic compounds. Moreover, the carotenoid pigments produced by this nonpathogenic Gram-positive bacterium have a variety of other potential applications. PMID:26691458

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

    PubMed Central

    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

  1. Response of Rhodococcus erythropolis strain IBBPo1 to toxic organic solvents

    PubMed Central

    Stancu, Mihaela Marilena

    2015-01-01

    Abstract Recently, there has been a lot of interest in the utilization of rhodococci in the bioremediation of petroleum contaminated environments. This study investigates the response of Rhodococcus erythropolis IBBPo1 cells to 1% organic solvents (alkanes, aromatics). A combination of microbiology, biochemical, and molecular approaches were used to examine cell adaptation mechanisms likely to be pursued by this strain after 1% organic solvent exposure. R. erythropolis IBBPo1 was found to utilize 1% alkanes (cyclohexane, n-hexane, n-decane) and aromatics (toluene, styrene, ethylbenzene) as the sole carbon source. Modifications in cell viability, cell morphology, membrane permeability, lipid profile, carotenoid pigments profile and 16S rRNA gene were revealed in R. erythropolis IBBPo1 cells grown 1 and 24 h on minimal medium in the presence of 1% alkanes (cyclohexane, n-hexane, n-decane) and aromatics (toluene, styrene, ethylbenzene). Due to its environmental origin and its metabolic potential, R. erythropolis IBBPo1 is an excellent candidate for the bioremediation of soils contaminated with crude oils and other toxic compounds. Moreover, the carotenoid pigments produced by this nonpathogenic Gram-positive bacterium have a variety of other potential applications. PMID:26691458

  2. Organic solvent vapor sensitive methylammonium lead trihalide film formation for efficient hybrid perovskite solar cells

    DOE PAGESBeta

    Lian, Jiarong; Wang, Qi; Yuan, Yongbo; Shao, Yuchuan; Huang, Jinsong

    2015-03-25

    In this study, the anisotropic electronic properties of the perovskite crystals originating from their non-cubic crystal structures can potentially give rise to the grain orientation correlated photovoltaic device performance. Here we report that an organic solvent vapor atmosphere introduced during the spin-coating and formation of perovskite films changes the orientation and size of perovskite grains. It was found that slightly larger but much more oriented methylammonium lead trihalide (CH3NH3PbI3) grains could be obtained under 1,2-dichlorobenzene (DCB) and dimethyl sulfoxide (DMSO) vapor atmospheres. The devices with more oriented grains outperformed regular devices with more random grains by a 50 mV largermore » open circuit voltage as well as a slightly increased fill factor. The device efficiency enhancement can be attributed to the longer charge recombination lifetime resulting from the reduced trap density and oriented grains. This result is important in providing guidelines for comparing the results from various groups because organic solvent vapors are generally present in a sealed glovebox for perovskite solar cell fabrication.« less

  3. Organic solvent vapor sensitive methylammonium lead trihalide film formation for efficient hybrid perovskite solar cells

    SciTech Connect

    Lian, Jiarong; Wang, Qi; Yuan, Yongbo; Shao, Yuchuan; Huang, Jinsong

    2015-03-25

    In this study, the anisotropic electronic properties of the perovskite crystals originating from their non-cubic crystal structures can potentially give rise to the grain orientation correlated photovoltaic device performance. Here we report that an organic solvent vapor atmosphere introduced during the spin-coating and formation of perovskite films changes the orientation and size of perovskite grains. It was found that slightly larger but much more oriented methylammonium lead trihalide (CH3NH3PbI3) grains could be obtained under 1,2-dichlorobenzene (DCB) and dimethyl sulfoxide (DMSO) vapor atmospheres. The devices with more oriented grains outperformed regular devices with more random grains by a 50 mV larger open circuit voltage as well as a slightly increased fill factor. The device efficiency enhancement can be attributed to the longer charge recombination lifetime resulting from the reduced trap density and oriented grains. This result is important in providing guidelines for comparing the results from various groups because organic solvent vapors are generally present in a sealed glovebox for perovskite solar cell fabrication.

  4. Organic solvents-free technique for determining sulfadimethoxine and its metabolites in chicken meat.

    PubMed

    Furusawa, Naoto

    2007-11-16

    A quick and cost-effective technique of sample preparation followed by a reversed-phase high performance liquid chromatography under "organic solvent-free" (=100% aqueous) conditions for the simultaneous quantifying of sulfadimethoxine (SDM) and its metabolites, 6-hydroxy SDM (6-OH) and N(4)-acetyl SDM (N(4)-Ac), in chicken muscle is presented. Analysis by HPLC with photo-diode array detector was performed using a short C1 column with an isocratic 0.04 mol/l citric acid mobile phase. The method was validated by the analyses of spiked chicken muscle samples, resulting recoveries (> or =84%; relative standard deviations < or =6%), analytical total time (<1/2 h/sample, where a batch of 12 samples in 4 h), and limits of quantitation (< or =0.1 microg/g). The decision limits and detection capability were 0.019-0.106 and 0.054-0.112 microg/g, respectively. No organic solvents were used at all.

  5. Expression and purification of organic solvent stable lipase from soil metagenomic library.

    PubMed

    Khan, Mahejibin; Jithesh, Kottur

    2012-06-01

    Gene for organic solvent stable lipase was overexpressed from soil metagenomic library. The clone with maximum activity was selected, and enzyme was purified by gel-permeation chromatography with a molecular mass of approx. 40 kDa. The deduced aminoacid sequence indicated that the protein belongs to the lipase family I.3 and containing a C-terminal secretion signal for ABC dependent transport together with possible motifs for Ca(2+) binding sites. The enzyme expressed maximum activity at 30 °C and pH 7.0 and found to be stable in pH and temperature ranging from 6.0-9.0 and 20-60 °C, respectively. Furthermore, the enzyme was found highly resistant to many organic solvents, especially isopropanol, DMSO, methanol, xylene and hexane. The enzyme showed enhanced activity in the presence of divalent cations (Mg(2+), Mn(2+), Ca(2+), Hg(2+), Cu(2+)), whereas the presence of trivalent cation (Fe(3+)) inhibited the activity.

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

    PubMed

    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. PMID:26541523

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

    PubMed

    Szermer-Olearnik, Bożena; Boratyński, Janusz

    2015-01-01

    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).

  8. Synthesis of alkyl esters by cutinase in miniemulsion and organic solvent media.

    PubMed

    de Barros, Dragana P C; Fonseca, Luís P; Cabral, Joaquim M S; Weiss, Clemens K; Landfester, Katharina

    2009-05-01

    The main objective of this work was studying and testing the nature and influence of reaction media (organic solvent vs. miniemulsion system) on the synthesis of alkyl esters catalyzed by Fusarium solani pisi cutinase. Ester synthesis and cutinase selectivity for different chain length of acids and alcohols (ethyl and hexyl) were evaluated. In iso-octane, after 1 h of reaction, cutinase exhibits rates of esterification between 0.24 micromol x mg(-)1 x min(-1) for ethyl oleate and 1.15 micromol x mg(-)1 x min(-1) for ethyl butyrate, while in a miniemulsion system the rates were from 0.05 for ethyl heptanoate to 0.76 micromol x mg(-1) x min(-1) for ethyl decanoate. The reaction rate for the synthesis of hexyl esters in a miniemulsion system was from 0.19 for hexyl heptanoate to 1.07 micromol x mg(-)1 x min(-1) for hexyl decanoate. High conversion yields of 95% at equilibrium after 8 h of reaction in iso-octane for pentanoic acid (C(5)) with ethanol at equimolar concentration (0.1 M) was achieved. Additionally, this work showed that a significant and unexpected shift in cutinase selectivity occurred towards longer chain length carboxylic acids (C(8)-C(10)) in miniemulsion system as compared to organic solvent (iso-octane) and previous studies in reverse micellar systems. The possibility of working with higher concentration of substrates, without inhibitory effect on the enzyme, was another advantage of the miniemulsion system.

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

    PubMed

    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.

  10. Tryptophanase from Escherichia coli: catalytic and spectral properties in water-organic solvents.

    PubMed

    Faleev, N G; Dementieva, I S; Zakomirdina, L N; Gogoleva, O I; Belikov, V M

    1994-08-01

    In water-methanol and water-dimethylformamide (DMF) (1:1 v/v) solutions tryptophanase from E.coli retains its abilities to form a quinonoid complex with quasisubstrates and to catalyze the decomposition of S-o-nitrophenyl-L-cysteine (SOPC). Both the KM and Vmax values decrease in water-organic media. The affinities of tryptophanase for L-alanine, L-tryptophan, oxindolyl-L-alanine and indole in aqueous methanol are decreased, the effect being stronger for the more hydrophobic substances. In a water solution tryptophanase catalizes the reaction of SOPC with indole to form L-tryptophan while in water-organic solvents only decomposition of SOPC is observed.

  11. Growth of columnar hydrogel colloidal crystals in water-organic solvent mixture.

    PubMed

    Zhou, Jun; Cai, Tong; Tang, Shijun; Marquez, Manuel; Hu, Zhibing

    2006-01-31

    A novel emulsion method has been demonstrated to grow columnar hydrogel colloidal crystals by mixing an aqueous suspension of poly-N-isopropylacrylamide-co-allylamine microgels with organic solvent, driven by the coalescence of micelles consisting of organic oil droplets coated by many microgels. This method leads to microgel colloidal crystals of several centimeters growing from the top to the bottom along the gravity direction. Both temperature and polymer concentration play critical roles for the formation of columnar crystals. A phase diagram has been determined, and it can be used as a guide to selectively grow different crystals, including columnar crystals and randomly oriented crystals, and enable the coexistence of columnar crystals and randomly oriented crystals.

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

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    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.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

  14. Solute-solvent interactions in micellar electrokinetic chromatography. 6. Optimization of the selectivity of lithium dodecyl sulfate-lithium perfluorooctanesulfonate mixed micellar buffers.

    PubMed

    Fuguet, Elisabet; Ràfols, Clara; Torres-Lapasió, José Ramón; García-Alvarez-Coque, María Celia; Bosch, Elisabeth; Rosés, Martí

    2002-09-01

    The optimization of the composition of mixed surfactants used as micellar electrokinetic chromatography (MEKC) pseudostationary phases is proposed as an effective method for the separation of complex mixtures of analytes. The solvation parameter model is used to select two surfactants (lithium dodecyl sulfate, LDS, and lithium perfluorooctanesulfonate, LPFOS) with contrasting solvation properties. Combination of these two surfactants allows variations of the solvation properties of MEKC pseudostationary phase along a wide range. Thus, the convenient variation of the proportion of both surfactants allows an effective control of the selectivity in such systems. An algorithm that predicts the overall resolution of a given mixture of compounds is described and applied to optimize the composition of the mixed surfactant for the separation of the mixture. The algorithm is based on the calculation of peak purities on simulated chromatograms as a function of the composition of the mixed LDS/LPFOS micellar buffer from data at several micellar buffer compositions. Successful separations were achieved for mixtures containing up to 20 compounds, in less than 12 min.

  15. Organic solvent simulations under non-periodic boundary conditions: A library of effective potentials for the GLOB model

    NASA Astrophysics Data System (ADS)

    Mancini, Giordano; Brancato, Giuseppe; Chandramouli, Balasubramanian; Barone, Vincenzo

    2015-04-01

    We extend the library of solvents that can be treated using the GLOB (general liquid optimized boundary) method, that allows to perform MD simulations under non-periodic boundary conditions (NPBC) optimizing effective potentials between explicit molecules and the boundary for four organic solvents: CHCl3, CCl4, CH3OH and CH3CN. We show that GLOB allows reducing the number of explicit solvent shells to be included, while yielding results comparable with PBC and significant advantages over simulations without explicit boundaries. Finally, we provide polynomial fittings for all available GLOB effective potentials (including SPC water) to simplify their implementation in NPBC MD simulations.

  16. 40 CFR Table 6 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2010 CFR

    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...

  17. 40 CFR Table 6 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 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...

  18. Self-assembled, aligned ZnO nanorod buffer layers for high-current-density, inverted organic photovoltaics.

    PubMed

    Rao, Arun D; Karalatti, Suresh; Thomas, Tiju; Ramamurthy, Praveen C

    2014-10-01

    Two different soft-chemical, self-assembly-based solution approaches are employed to grow zinc oxide (ZnO) nanorods with controlled texture. The methods used involve seeding and growth on a substrate. Nanorods with various aspect ratios (1-5) and diameters (15-65 nm) are grown. Obtaining highly oriented rods is determined by the way the substrate is mounted within the chemical bath. Furthermore, a preheat and centrifugation step is essential for the optimization of the growth solution. In the best samples, we obtain ZnO nanorods that are almost entirely oriented in the (002) direction; this is desirable since electron mobility of ZnO is highest along this crystallographic axis. When used as the buffer layer of inverted organic photovoltaics (I-OPVs), these one-dimensional (1D) nanostructures offer: (a) direct paths for charge transport and (b) high interfacial area for electron collection. The morphological, structural, and optical properties of ZnO nanorods are studied using scanning electron microscopy, X-ray diffraction, and ultraviolet-visible light (UV-vis) absorption spectroscopy. Furthermore, the surface chemical features of ZnO films are studied using X-ray photoelectron spectroscopy and contact angle measurements. Using as-grown ZnO, inverted OPVs are fabricated and characterized. For improving device performance, the ZnO nanorods are subjected to UV-ozone irradiation. UV-ozone treated ZnO nanorods show: (i) improvement in optical transmission, (ii) increased wetting of active organic components, and (iii) increased concentration of Zn-O surface bonds. These observations correlate well with improved device performance. The devices fabricated using these optimized buffer layers have an efficiency of ∼3.2% and a fill factor of 0.50; this is comparable to the best I-OPVs reported that use a P3HT-PCBM active layer.

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

    PubMed

    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. PMID:27238487

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

    PubMed

    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.

  1. Competitive Sorption and Desorption of Chlorinated Organic Solvents (DNAPLs) in Engineered Natural Organic Matter

    SciTech Connect

    Tang, Jixin; Weber, Walter J., Jr.

    2004-03-31

    The effects of artificially accelerated geochemical condensation and maturation of natural organic matter on the sorption and desorption of trichloroethylene (TCE) and tetrachloroethylene (PCE) were studied. The sorption and desorption of TCE in the presence and absence of the competing PCE and 1,2-dichlorobenzene (DCB) were also examined. A sphagnum peat comprising geologically young organic matter was artificially ''aged'' using superheated water, thus increasing the aromaticity and the degree of condensation of its associated organic matter. The sorption of all solutes tested were increased remarkably and their respective desorptions reduced, by the aged peat. The sorption capacities and isotherm nonlinearities of the peat for both TCE and PCE were found to increase as treatment temperature increased. In the competitive sorption studies, both PCE and DCB were found to depress TCE sorption, with PCE having greater effects than DCB, presumably because the molecular structure o f the former is more similar to that of TCE.

  2. Multidimensional analysis of the effect of occupational exposure to organic solvents on lung cancer risk: the ICARE study

    PubMed Central

    Mattei, Francesca; Liverani, Silvia; Guida, Florence; Matrat, Mireille; Cenée, Sylvie; Azizi, Lamiae; Menvielle, Gwenn; Sanchez, Marie; Pilorget, Corinne; Lapôtre-Ledoux, Bénédicte; Luce, Danièle; Richardson, Sylvia; Stücker, Isabelle

    2016-01-01

    Background The association between lung cancer and occupational exposure to organic solvents is discussed. Since different solvents are often used simultaneously, it is difficult to assess the role of individual substances. Objectives The present study is focused on an in-depth investigation of the potential association between lung cancer risk and occupational exposure to a large group of organic solvents, taking into account the well-known risk factors for lung cancer, tobacco smoking and occupational exposure to asbestos. Methods We analysed data from the Investigation of occupational and environmental causes of respiratory cancers (ICARE) study, a large French population-based case–control study, set up between 2001 and 2007. A total of 2276 male cases and 2780 male controls were interviewed, and long-life occupational history was collected. In order to overcome the analytical difficulties created by multiple correlated exposures, we carried out a novel type of analysis based on Bayesian profile regression. Results After analysis with conventional logistic regression methods, none of the 11 solvents examined were associated with lung cancer risk. Through a profile regression approach, we did not observe any significant association between solvent exposure and lung cancer. However, we identified clusters at high risk that are related to occupations known to be at risk of developing lung cancer, such as painters. Conclusions Organic solvents do not appear to be substantial contributors to the occupational risk of lung cancer for the occupations known to be at risk. PMID:26911986

  3. The Effect of Organic Solvents and Other Parameters on Trypsin-Catalyzed Hydrolysis of Na-Benzoyl-arginine-p-nitroanilide. A Project-Oriented Biochemical Experiment

    NASA Astrophysics Data System (ADS)

    Correia, L. C.; Bocewicz, A. C.; Esteves, S. A.; Pontes, M. G.; Versieux, L. M.; Teixeira, S. M. R.; Santoro, M. M.; Bemquerer, M. P.

    2001-11-01

    The study of enzymatic catalysis is a classical biochemistry experiment for undergraduate classes. We propose the utilization of the serine protease trypsin to discuss several parameters affecting enzyme catalysis. Hydrolysis of the chromogenic substrate Na -benzoyl-arginine-p-nitroanilide (BApNA) was followed by spectrophotometric monitoring. The optimal pH and temperature values were found to be 8.0 and 40 °C, respectively. Km and Vmax values were obtained by adjustment to Michaelis-Menten, Lineweaver-Burke, and Hanes equations. We then investigated the effect of organic solvents (a series of alcohols) on the hydrolysis of the chromogenic substrate. The reaction rate was reduced in the presence of methanol and further reduced by ethanol, 1-propanol, and 2-propanol, when compared to the data obtained with buffer. Finally the students were asked to measure the molar absorptivity of p-nitrophenol in the presence of the alcohols employed for the kinetic experiments. Thus they could learn that the value of this parameter varies with the solvent. These experiments were designed as a project-oriented approach to teach biochemistry methodologies and theoretical aspects of enzyme kinetics. They took about four months with four to six hours per week spent in the laboratory.

  4. Thermostability and reactivity in organic solvent of O-phospho-L-serine sulfhydrylase from hyperthermophilic archaeon Aeropyrum pernix K1.

    PubMed

    Nakamura, Takashi; Asai, Shinji; Nakata, Kaori; Kunimoto, Kohei; Oguri, Masateru; Ishikawa, Kazuhiko

    2015-01-01

    O-phospho-l-serine sulfhydrylase (OPSS) from archaeon Aeropyrum pernix K1 is able to synthesize l-cysteine even at 80 °C. In this article, we compared thermal stability and reactivity in organic solvent of OPSS with those of O-acetyl-l-serine sulfhydrylase B (OASS-B) from Escherichia coli. As a result, the thermostability of OPSS was much higher than that of OASS-B. Moreover, the activity of OPSS increased in the reaction mixture containing the organic solvent, such as N, N'-dimethyl formamide and 1,4-dioxane, whereas that of OASS-B gradually decreased as the content of organic solvent increased. From the crystal structural analysis, the intramolecular electrostatic interactions of N-terminal domain in OPSS seemed to be correlated with the tolerance of OPSS to high temperature and organic solvent. These results indicate that OPSS is more superior to OASS-B for the industrial production of l-cysteine and unnatural amino acids that are useful pharmaceuticals in the presence of organic solvent.

  5. Molecular recognition with metal containing supramolecular compounds: Soluble tetradentate dithioglyoximes for the detection of organic solvents in the gas phase

    SciTech Connect

    Oeztuerk, Z.Z.

    1996-12-31

    Supramolecular structures have been widely investigated for their specific recognition of ions. Recently, they have been also used to detect neutral molecules and especially organic solvents in the gas phase. In this context, the authors developed a new type of supramolecular structures for the recognition of the organic solvent molecules by their selective incorporation to the bulk of thin films. The authors synthesized a series of the soluble tetradentate dithiogloximes which included mono-, tri-, and pentanuclear metal complexes as well as the heteronuclear polymers. Thin layers of these compounds were prepared from their solutions by evaporating their volatile organic solvents. The subsequent exposure of these films to the same organic solvent molecules in air shows drastic transducer signals, i.e., changes in masses and capacitances due to selective interactions of coordinatively and electronically unsaturated metal complexes with gas molecules. The organic solvents investigated in this work are dichloromethane, trichloromethane, tetrachloromethane, trichloroethylene, tetrachloroethylene, acetone, benzene, toluene, n-hexane, n-octane, methanol, ethanol and n-propanol. Sensor responses were monitored with interdigital capacitor (IDC) and quartz crystal oscillators (QCM).

  6. Production of Thermostable Organic Solvent Tolerant Keratinolytic Protease from Thermoactinomyces sp. RM4: IAA Production and Plant Growth Promotion.

    PubMed

    Verma, Amit; Singh, Hukum; Anwar, Mohammad S; Kumar, Shailendra; Ansari, Mohammad W; Agrawal, Sanjeev

    2016-01-01

    There are several reports about the optimization of protease production, but only few have optimized the production of organic solvent tolerant keratinolytic proteases that show remarkable exploitation in the development of the non-polluting processes in biotechnological industries. The present study was carried with aim to optimize the production of a thermostable organic solvent tolerant keratinolytic protease Thermoactinomyces sp. RM4 utilizing chicken feathers. Thermoactinomyces sp. RM4 isolated from the soil sample collected from a rice mill wasteyard site near Kashipur, Uttrakhand was identified on the basis of 16S rDNA analysis. The production of organic solvent tolerant keratinolytic protease enzyme by Thermoactinomyces sp. RM4 was optimized by varying physical culture conditions such as pH (10.0), temperature (60°C), inoculum percentage (2%), feather concentration (2%) and agitation rate (2 g) for feather degradation. The result showed that Thermoactinomyces sp. RM4 potentially produces extra-cellular thermostable organic solvent tolerant keratinolytic protease in the culture medium. Further, the feather hydrolysate from keratinase production media showed plant growth promoting activity by producing indole-3-acetic acid itself. The present findings suggest that keratinolytic protease from Thermoactinomyces sp. RM4 offers enormous industrial applications due to its organic solvent tolerant property in peptide synthesis, practical role in feather degradation and potential function in plant growth promoting activity, which might be a superior candidate to keep ecosystem healthy and functional. PMID:27555836

  7. Production of Thermostable Organic Solvent Tolerant Keratinolytic Protease from Thermoactinomyces sp. RM4: IAA Production and Plant Growth Promotion

    PubMed Central

    Verma, Amit; Singh, Hukum; Anwar, Mohammad S.; Kumar, Shailendra; Ansari, Mohammad W.; Agrawal, Sanjeev

    2016-01-01

    There are several reports about the optimization of protease production, but only few have optimized the production of organic solvent tolerant keratinolytic proteases that show remarkable exploitation in the development of the non-polluting processes in biotechnological industries. The present study was carried with aim to optimize the production of a thermostable organic solvent tolerant keratinolytic protease Thermoactinomyces sp. RM4 utilizing chicken feathers. Thermoactinomyces sp. RM4 isolated from the soil sample collected from a rice mill wasteyard site near Kashipur, Uttrakhand was identified on the basis of 16S rDNA analysis. The production of organic solvent tolerant keratinolytic protease enzyme by Thermoactinomyces sp. RM4 was optimized by varying physical culture conditions such as pH (10.0), temperature (60°C), inoculum percentage (2%), feather concentration (2%) and agitation rate (2 g) for feather degradation. The result showed that Thermoactinomyces sp. RM4 potentially produces extra-cellular thermostable organic solvent tolerant keratinolytic protease in the culture medium. Further, the feather hydrolysate from keratinase production media showed plant growth promoting activity by producing indole-3-acetic acid itself. The present findings suggest that keratinolytic protease from Thermoactinomyces sp. RM4 offers enormous industrial applications due to its organic solvent tolerant property in peptide synthesis, practical role in feather degradation and potential function in plant growth promoting activity, which might be a superior candidate to keep ecosystem healthy and functional. PMID:27555836

  8. 40 CFR Table 7 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Default Organic HAP Mass Fraction for Petroleum Solvent Groups a 7 Table 7 to Subpart KKKK of Part 63 Protection of Environment ENVIRONMENTAL... Metal Cans Pt. 63, Subpt. KKKK, Table 7 Table 7 to Subpart KKKK of Part 63—Default Organic HAP...

  9. 40 CFR Table 7 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Petroleum Solvent Groups a

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for Petroleum Solvent Groups a 7 Table 7 to Subpart KKKK of Part 63 Protection of Environment ENVIRONMENTAL... Metal Cans Pt. 63, Subpt. KKKK, Table 7 Table 7 to Subpart KKKK of Part 63—Default Organic HAP...

  10. Ionic conduction and self-diffusion near infinitesimal concentration in lithium salt-organic solvent electrolytes

    NASA Astrophysics Data System (ADS)

    Aihara, Yuichi; Sugimoto, Kyoko; Price, William S.; Hayamizu, Kikuko

    2000-08-01

    The Debye-Hückel-Onsager and Nernst-Einstein equations, which are based on two different conceptual approaches, constitute the most widely used equations for relating ionic conduction to ionic mobility. However, both of these classical (simple) equations are predictive of ionic conductivity only at very low salt concentrations. In the present work the ionic conductivity of four organic solvent-lithium salt-based electrolytes were measured. These experimental conductivity values were then contrasted with theoretical values calculated using the translational diffusion (also known as self-diffusion or intradiffusion) coefficients of all of the species present obtained using pulsed-gradient spin-echo (1H, 19F and 7Li) nuclear magnetic resonance self-diffusion measurements. The experimental results verified the applicability of both theoretical approaches at very low salt concentrations for these particular systems as well as helping to clarify the reasons for the divergence between theory and experiment. In particular, it was found that the correspondence between the Debye-Hückel-Onsager equation and experimental values could be improved by using the measured solvent self-diffusion values to correct for salt-induced changes in the solution viscosity. The concentration dependence of the self-diffusion coefficients is discussed in terms of the Jones-Dole equation.

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

    SciTech Connect

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

    1998-09-30

    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{sub 4}) was examined using a heated air stream on a Rocky Flats combustible residue surrogate contaminated with CCl{sub 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.

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

    PubMed

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

    2012-08-01

    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.

  13. Photodegradation of Polyfluorinated Dibenzo-p-Dioxins in Organic Solvents: Experimental and Theoretical Studies.

    PubMed

    Zeng, Xiaolan; Qu, Ruijuan; Feng, Mingbao; Chen, Jing; Wang, Liansheng; Wang, Zunyao

    2016-08-01

    Eighteen polyfluorinated dibenzo-p-dioxins (PFDDs) were synthesized by pyrolysis of fluorophenols. Using a 500 W Xe lamp as the light source, the PFDDs photodegradation kinetics in n-hexane were investigated. The photolysis reactions obeyed the pseudo-first-order rate equation, and higher fluorinated PFDDs tended to photolyze more slowly. Theoretically calculated parameters reflecting the molecular structural properties were used to develop a new model of PFDDs photolysis rates. The results indicated that the substitution pattern for fluorine atoms and the C-O bond length were major factors in the photolysis of PFDDs. We selected octafluorinated dibenzo-p-dioxin (OFDD) as a representative PFDDs to explore the influence of solvent on the photolysis rate of PFDDs, and the results indicated that neither the polarity nor donor hydrogen of organic solvents are independent influencing factors. Mechanistic pathways for the photolysis of OFDD in n-hexane were first studied. The results indicated that photodegradation of OFDD produces octafluorinated dihydroxybiphenyls, octafluorinated phenoxyphenols, and fluorinated phenols. The major pathway for photodegradation of OFDD was C-O bond cleavage. Defluorination reactions did not occur during the photolysis process. PMID:27380414

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

    PubMed Central

    Kuchenbuch, Andrea

    2015-01-01

    Abstract 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. PMID:27308192

  15. Uptake of 10 polar organic solvents during short-term respiration.

    PubMed

    Kumagai, S; Oda, H; Matsunaga, I; Kosaka, H; Akasaka, S

    1999-04-01

    Respiratory uptake was investigated for 10 polar organic solvents with high blood/air partition coefficients (lambda(blood/air)): ethyl acetate (lambda(blood/air), 77), methyl iso-butyl ketone (90), methyl acetate (90), methyl propyl ketone (150), acetone (245), iso-pentyl alcohol (381), iso-propyl alcohol (848), methyl alcohol (2590), ethylene glycol monobutyl ether (EGBE, 7970), and propylene glycol monomethyl ether (PGME, 12380). Test-air concentrations (Cinh) were 25 to 200 ppm. Four healthy male volunteers inhaled the test air for 10 min at rest and then room air for 5 min. The percentage of solvent in the end-exhaled air and in the mixed-exhaled air increased after the start of the test-air respiration, and reached a quasi-steady-state level within a few min. The speeds of these increases at the start of the test-air respiration became lower as lambda(blood/air) increased. The mean uptakes (U) for the last five min of the test air respiration were 67.3, 52.9, 60.4, 53.0, 52.6, 63.0, 60.3, 60.8, 79.7, and 81.3%, respectively, for ethyl acetate, methyl iso-butyl ketone, methyl acetate, methyl propyl ketone, acetone, iso-pentyl alcohol, iso-propyl alcohol, methyl alcohol, EGBE and PGME. Thus, U values of the alcohols were higher than those of the ketones and lower than the glycol ethers. The overall view, except for esters, showed that U increased with lambda(water/air) increases. This tendency can be explained by a hypothesis that solvent absorbed in the mucus layer of the respiratory tract is removed by the bronchial blood circulation. U values of ethyl acetate and methyl acetate were higher than those of methyl iso-butyl ketone and methyl propyl ketone, though the lambda(blood/air) values of these esters were nearly equal to those of the ketones. For the respiration of the esters, their metabolites, ethyl alcohol and methyl alcohol, were detected in the exhaled air. The exhalation percentage of the metabolites increased after the start of test-air respiration

  16. The effects of organic solvents and their co-solvents on the optical, structural, morphological of P3HT:PCBM organic solar cells

    NASA Astrophysics Data System (ADS)

    Kadem, Burak Y.; Hassan, Aseel K.; Cranton, Wayne

    2016-07-01

    The effect of different solvents on the optical, structural, morphology and solar cell performance of P3HT:PCBM based devices were carried out using UV-visible absorption spectroscopy, XRD, AFM, SEM, electrical conductivity as well as current density-voltage (J-V) measurements in dark and under illumination. Chloroform (CF), chlorobenzene (CB), di-chlorobenzene (DCB), and their mixtures (DCB:CB, DCB:CF and CF:CB) in the ratio 1:1 were used as solvents to produce active layers of P3HT:PCBM heterojunctions. UV-visible absorption spectra have demonstrated different absorption intensities subject to the used solvents as well as a decrease in the optical bandgap from around 1.9eV to 1.8eV. AFM and SEM images gave an indication on the films' morphological properties, which have exhibited different topographies due to the used solvent. The electrical conductivity as well as the dark J-V characteristics were analysed using Richardson-Schottky model as well as space charge limited conduction theory to evaluate the diode properties of the produced solar cells. The electrical conductivity were found to vary from 9.7-77.7 mS.cm-1 and the higher values were associated with using CB:CF co-solvents based devices while the series resistance decreased from 33.3KΩ to 0.54KΩ using the same co-solvents. This was associated with an increase in the charge carriers' mobility that reached 6.69x10-6 cm2V-1s-1 in CB:CF based device. OSC devices produced using CB:CF co-solvents has exhibited the highest performance with PCE=2.73%, FF=53% and Jsc=8.3mA.cm-2 while Voc remained unchanged.

  17. Acid neutralizing processes in an alpine watershed front range, Colorado, U.S.A.-1: Buffering capacity of dissolved organic carbon in soil solutions

    USGS Publications Warehouse

    Iggy, Litaor M.; Thurman, E.M.

    1988-01-01

    Soil interstitial waters in the Green Lakes Valley, Front Range, Colorado were studied to evaluate the capacity of the soil system to buffer acid deposition. In order to determine the contribution of humic substances to the buffering capacity of a given soil, dissolved organic carbon (DOC) and pH of the soil solutions were measured. The concentration of the organic anion, Ai-, derived from DOC at sample pH and the concentration of organic anion, Ax- at the equivalence point were calculated using carboxyl contents from isolated and purified humic material from soil solutions. Subtracting Ax- from Ai- yields the contribution of humic substances to the buffering capacity (Aequiv.-). Using this method, one can evaluate the relative contribution of inorganic and organic constituents to the acid neutralizing capacity (ANC) of the soil solutions. The relative contribution of organic acids to the overall ANC was found to be extremely important in the alpine wetland (52%) and the forest-tundra ecotone (40%), and somewhat less important in the alpine tundra sites (20%). A failure to recognize the importance of organic acids in soil solutions to the ANC will result in erroneous estimates of the buffering capacity in the alpine environment of the Front Range, Colorado. ?? 1988.

  18. Separation of switchgrass bio-oil by water/organic solvent addition and pH adjustment

    DOE PAGESBeta

    Park, Lydia Kyoung-Eun; Ren, Shoujie; Yiacoumi, Sotira; Ye, X. Philip; Borole, Abhijeet P.; Tsouris, Costas

    2016-01-29

    Applications of bio-oil are limited by its challenging properties including high moisture content, low pH, high viscosity, high oxygen content, and low heating value. Separation of switchgrass bio-oil components by adding water, organic solvents (hexadecane and octane), and sodium hydroxide may help to overcome these issues. Acetic acid and phenolic compounds were extracted in aqueous and organic phases, respectively. Polar chemicals, such as acetic acid, did not partition in the organic solvent phase. Acetic acid in the aqueous phase after extraction is beneficial for a microbial-electrolysis-cell application to produce hydrogen as an energy source for further hydrodeoxygenation of bio-oil. Organicmore » solvents extracted more chemicals from bio-oil in combined than in sequential extraction; however, organic solvents partitioned into the aqueous phase in combined extraction. When sodium hydroxide was added to adjust the pH of aqueous bio-oil, organic-phase precipitation occurred. As the pH was increased, a biphasic aqueous/organic dispersion was formed, and phase separation was optimized at approximately pH 6. The neutralized organic bio-oil had approximately 37% less oxygen and 100% increased heating value than the initial centrifuged bio-oil. In conclusion, the less oxygen content and increased heating value indicated a significant improvement of the bio-oil quality through neutralization.« less

  19. Enhanced concentration of dispersed carbon nanofibres in organic solvents through their functionalization by fluorination.

    PubMed

    Nomède-Martyr, Nadiège; Disa, Elodie; Guérin, Katia; Dubois, Marc; Frezet, Lawrence; Hamwi, André

    2013-06-15

    Covalent functionalization through pure molecular gaseous fluorination has been applied on carbon nanofibres. Nuclear magnetic resonance and thermal gravimetric analysis investigations have been performed on fluorinated carbon nanofibres in order to determine the chemical and thermal stability of the C-F bonding. The high covalency obtained allows no significant modification of the physicochemical nanostructure of fluorinated carbon nanofibres after sonification. Such modification of surface chemistry leads to a high increase in the limit concentration of dispersed carbon nanofibres in organic solvents without surfactant. An exciting maximum of 570 mg L(-1) of fluorinated nanofibres can be homogeneously dispersed in N-methylpyrrolidone, whereas 310 mg L(-1) is the maximum for non-fluorinated carbon nanofibres. In order to understand such dispersibility differences, Hildebrand and Hansen solubility theory has been used.

  20. Molecular Characteristics of Kraft-AQ Pulping Lignin Fractionated by Sequential Organic Solvent Extraction

    PubMed Central

    Wang, Kun; Xu, Feng; Sun, Runcang

    2010-01-01

    Kraft-AQ pulping lignin was sequentially fractionated by organic solvent extractions and the molecular properties of each fraction were characterized by chemical degradation, GPC, UV, FT-IR, 13C-NMR and thermal analysis. The average molecular weight and polydispersity of each lignin fraction increased with its hydrogen-bonding capacity (Hildebrand solubility parameter). In addition, the ratio of the non-condensed guaiacyl/syringyl units and the content of β-O-4 linkages increased with the increment of the lignin fractions extracted successively with hexane, diethylether, methylene chloride, methanol, and dioxane. Furthermore, the presence of the condensation reaction products was contributed to the higher thermal stability of the larger molecules. PMID:21152286

  1. Magnetic graphene foam for efficient adsorption of oil and organic solvents.

    PubMed

    Yang, Sudong; Chen, Lin; Mu, Lei; Ma, Peng-Cheng

    2014-09-15

    This paper reported the preparation of magnetic graphene foam loaded with magnetite (Fe3O4) nanoparticles and its application for the adsorption of oil and organic solvents. The foam with porous and hierarchical structures was derived from graphene oxide film reduced by gaseous reduction in a hydrothermal system. Drastically different morphologies of Fe3O4 nanoparticles with nanosheet arrays or cubic structures were observed on graphene foam by controlling the reduction degree of graphene oxide under mild conditions. Benefiting from the integration of porous structures and magnetic properties, the graphene foam manifests outstanding oil adsorption capacity, high restoration for absorbates as well as excellent recyclability and stability under cyclic operations. The simple and effective strategy for the preparation of graphene foams developed in this study may offer a new alternative for scale-up production of graphene materials used for the cleanup of oil spills. PMID:24974246

  2. A One-Step, Solvothermal Reduction Method for Producing Reduced Graphene Oxide Dispersions in Organic Solvents

    PubMed Central

    Dubin, Sergey; Gilje, Scott; Wang, Kan; Tung, Vincent C.; Cha, Kitty; Hall, Anthony S.; Farrar, Jabari; Varshneya, Rupal; Yang, Yang; Kaner, Richard B.

    2014-01-01

    Refluxing graphene oxide (GO) in N-methyl-2-pyrrolidinone (NMP) results in deoxygenation and reduction to yield a stable colloidal dispersion. The solvothermal reduction is accompanied by a color change from light brown to black. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) images of the product confirm the presence of single sheets of the solvothermally reduced graphene oxide (SRGO). X-ray photoelectron spectroscopy (XPS) of SRGO indicates a significant increase in intensity of the C=C bond character, while the oxygen content decreases markedly after the reduction is complete. X-ray diffraction analysis of SRGO shows a single broad peak at 26.24° 2θ (3.4 Å), confirming the presence of graphitic stacking of reduced sheets. SRGO sheets are redispersible in a variety of organic solvents, which may hold promise as an acceptor material for bulk heterojunction photovoltaic cells, or electromagnetic interference shielding applications. PMID:20586422

  3. [Toxicology of chemical substances (metals and organic solvents): management as an occupational physician].

    PubMed

    Ueno, Susumu

    2013-10-01

    Even in Japan, there was a time when cases of occupational poisoning had frequently occurred, which led to the enactment of the Industrial Safety and Health Act in 1972. Currently, the use of only a part of chemical substances utilized in the workplace is regulated according to their designated hazardous level, but there are many other substances whose toxicities have not been elucidated. Risk assessment is now required of entrepreneurs in all categories of industry by the recently-revised Industrial Safety and Health Act. This article will focus on the toxicology of metals and organic solvents, and it will discuss how occupational physicians should manage chemicals, including the ones whose toxicities have not been clarified. PMID:24107340

  4. A Red-Emitting Luminescent Material Capable of Detecting Low Water Content in Organic Solvents.

    PubMed

    Wang, Tianren; Li, Huanrong

    2016-08-22

    A new red-emitting luminescent material was prepared from a gel formed by simply mixing EuCl3 ⋅6 H2 O and 4'-para-phenylcarboxyl-2,2':6',2''-terpyridine (Hcptpy) in a molar ratio of 1:2 in anhydrous ethanol at room temperature. It shows bright red luminescence dominated by the (5) D0 →(7) F2 transition of Eu(3+) , a long lifetime (1.16 ms), a high absolute quantum yield (48.2 %), and good thermostability (stable up to 500 °C). In addition, the luminescence of the material can be easily quenched by contact with water, which makes it suitable for detecting low contents of water (0.1-1.5 vol %) in common organic solvents such as diethyl ether and THF.

  5. Resin-supported catalysts for CuAAC click reactions in aqueous or organic solvents.

    PubMed

    Presolski, Stanislav I; Mamidyala, Sreeman K; Manzenrieder, Florian; Finn, M G

    2012-10-01

    The copper-catalyzed azide-alkyne cycloaddition click reaction is a valuable process for the synthesis of libraries of drug candidates, derivatized polymers and materials, and a wide variety of other functional molecules. In some circumstances, the removal of the copper catalyst is both necessary and inconvenient. We describe here two immobilized forms of a Cu-binding ligand that has been shown to accelerate triazole formation under many different conditions, using different resin supports that are appropriate for aqueous or organic solvents. Copper leaching from these resins was modest, allowing them to be reused in many reaction/filtration cycles without recharging with metal ion. The utility of this catalyst form was demonstrated in the convenient synthesis of 20 N-acetylgalactosamine derivatives for biological testing. PMID:22946559

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

    PubMed

    Lawrence, Ann-Marie; Besir, H Uuml Seyin

    2009-01-01

    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. PMID:19684570

  7. Screening of lipase carriers for reactions in water, biphasic and pure organic solvent systems.

    PubMed

    Hrydziuszko, Zofia; Dmytryk, Agnieszka; Majewska, Paulina; Szymańska, Katarzyna; Liesiene, Jolanta; Jarzębski, Andrzej; Bryjak, Jolanta

    2014-01-01

    In bioprocesses lipases are typically used in immobilized form, irrespective of type of reaction systems, to ensure an even distribution of catalysts in water restricted media and/or to facilitate separation and reuse. In these studies we report on the selection of appropriate enzyme-carrier preparation for hydrolysis reaction in aqueous and biphasic systems and transesterification in organic solvent. For this Candida rugosa lipase was bound by adsorption or covalent attachment onto various carriers to give 24 preparations. Selection of proper preparation was based on reactivity, thermal stability (4 h at 60°C), possibility of drying and operational stability in 17-23 successive batch processes of 4-nitrophenyl palmitate hydrolysis in water. Activity of preparations varied from 20 to 5100 U∙mL(-1) but the most stable preparations were those of moderate activity: bound by adsorption or covalent attachment to NH₂-Kieselgel or acrylic carrier (retained activity over 90%). Selected preparations were used for hydrolysis of ethyl (1-butyryloxyethyl)-phenylphosphinate in biphasic system, and, after drying, in ethyl (1-hydroxyethyl)-phenyl-phosphinate transesterification. In this study operational stability was the principal criterion of selection. In water system, lipase covalently bound to NH₂-Kieselgel was the best - preserved 50% of initial activity in consecutive batch processes. In biphasic system and lipase covalently bound to acrylic and NH₂-Kieselgel the values were 90 or 77%, respectively, whereas in organic solvent, when lipase was immobilized on NH₂-Kieselgel by adsorption, it was 50%. Thus, NH₂-Kieselgel appears to be an universal matrix for investigated lipase immobilization and can be used in all reaction systems.

  8. Solvent wash solution

    DOEpatents

    Neace, James C.

    1986-01-01

    Process for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 volume percent of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

  9. Solvent wash solution

    DOEpatents

    Neace, J.C.

    1984-03-13

    A process is claimed for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 vol % of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

  10. Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives.

    PubMed

    Schulz, Gisela L; Urdanpilleta, Marta; Fitzner, Roland; Brier, Eduard; Mena-Osteritz, Elena; Reinold, Egon; Bäuerle, Peter

    2013-01-01

    The optimization of solution-processed organic bulk-heterojunction solar cells with the acceptor-substituted quinquethiophene DCV5T-Bu 4 as donor in conjunction with PC61BM as acceptor is described. Power conversion efficiencies up to 3.0% and external quantum efficiencies up to 40% were obtained through the use of 1-chloronaphthalene as solvent additive in the fabrication of the photovoltaic devices. Furthermore, atomic force microscopy investigations of the photoactive layer gave insight into the distribution of donor and acceptor within the blend. The unique combination of solubility and thermal stability of DCV5T-Bu 4 also allows for fabrication of organic solar cells by vacuum deposition. Thus, we were able to perform a rare comparison of the device characteristics of the solution-processed DCV5T-Bu 4 :PC61BM solar cell with its vacuum-processed DCV5T-Bu 4 :C60 counterpart. Interestingly in this case, the efficiencies of the small-molecule organic solar cells prepared by using solution techniques are approaching those fabricated by using vacuum technology. This result is significant as vacuum-processed devices typically display much better performances in photovoltaic cells.

  11. Discovery a novel organic solvent tolerant esterase from Salinispora arenicola CNP193 through genome mining.

    PubMed

    Fang, Yaowei; Wang, Shujun; Liu, Shu; Jiao, Yuliang

    2015-09-01

    An esterase gene, encoding a 325-amino-acid protein (SAestA), was mined form obligate marine actinomycete strain Salinispora arenicola CNP193 genome sequence. Phylogenetic analysis of the deduced amino acid sequence showed that the enzyme belonged to the family IV of lipolytic enzymes. The gene was cloned, expressed in Escherichia coli as a His-tagged protein, purified and characterized. The molecular weight of His-tagged SAestA is ∼38 kDa. SAestA-His6 was active in a temperature (5-40 °C) and pH range (7.0-11.0), and maximal activity was determined at pH 9.0 and 30 °C. The activity was severely inhibited by Hg(2+), Cu(2+), and Zn(2+). In particular, this enzyme showed remarkable stability in presence of organic solvents (25%, v/v) with log P>2.0 even after incubation for 7 days. All these characteristics suggested that SAestA may be a potential candidate for application in industrial processes in aqueous/organic media. PMID:26118483

  12. Reactions of organic ions at ambient surfaces in a solvent-free environment.

    PubMed

    Badu-Tawiah, Abraham K; Cyriac, Jobin; Cooks, R Graham

    2012-05-01

    Solvent-free ion/surface chemistry is studied at atmospheric pressure, specifically pyrylium cations, are reacted at ambient surfaces with organic amines to generate pyridinium ions. The dry reagent ions were generated by electrospraying a solution of the organic salt and passing the resulting electrosprayed droplets pneumatically through a heated metal drying tube. The dry ions were then passed through an electric field in air to separate the cations from anions and direct the cations onto a gold substrate coated with an amine. This nontraditional way of manipulating polyatomic ions has provided new chemical insights, for example, the surface reaction involving dry isolated 2,4,6-triphenylpyrylium cations and condensed solid-phase ethanolamine was found to produce the expected N-substituted pyridinium product ion via a pseudobase intermediate in a regiospecific fashion. In solution however, ethanolamine was observed to react through its N-centered and O-centered nucleophilic groups to generate two isomeric products via 2H-pyran intermediates. The O-centered nucleophile reacted less rapidly to give the minor product. The surface reaction product was characterized in situ by surface enhanced Raman spectroscopy, and ex situ using mass spectrometry and H/D exchange, and found to be chemically the same as the major pyridinium solution-phase reaction product. PMID:22290484

  13. PEGylation of G-CSF in organic solvent markedly increase the efficacy and reactivity through protein unfolding, hydrolysis inhibition and solvent effect.

    PubMed

    Peng, Fei; Liu, Yongdong; Li, Xiunan; Sun, Lijing; Zhao, Dawei; Wang, Qingqing; Ma, Guanghui; Su, Zhiguo

    2014-01-20

    Previous studies demonstrated that hydrophobic proteins could be PEGylated in organic phase rather than water phase. It is still not known what the difference is for a hydrophilic protein's PEGylation in these two different phases. In this study, granulocyte colony stimulating factor (G-CSF) was dissolved in neat dimethyl sulfoxide (DMSO) and was PEGylated. In comparison with the PEGylation in water solution, the PEGylation degree in the organic solvent increased by 33% and 42% for PEG-maleimide (MAL-PEG) and PEG-succinimidyl carbonate (SC-PEG) respectively. Structure analysis revealed that the protein was unfolded in DMSO, which could make the PEGylated sites of G-CSF easily accessible. The hydrolysis half-life in water solution was 40min and 9h for SC-PEG and MAL-PEG respectively. However, in DMSO solvent, PEGs were very stable and no hydrolysis could be detected. Stopped-flow demonstrated that the conjugation speed of G-CSF by MAL-PEG and SC-PEG in DMSO were 1.6×10(4) and 2×10(2) times faster than those in aqueous solution. The remarkable acceleration could mainly be attributed to an increase of protein nucleophilicity in DMSO. The results of this study could be referential to industrial application where the cost of PEG reagents and the speed of reaction on large scale are very important. PMID:24315970

  14. A simple solvent collection technique for a dispersive liquid-liquid microextraction of parabens from aqueous samples using low-density organic solvent.

    PubMed

    Cabuk, Hasan; Akyüz, Mehmet; Ata, Sevket

    2012-10-01

    A simple technique for the collection of an extraction solvent lighter than water after dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with ultraviolet detection was developed for the determination of four paraben preservatives in aqueous samples. After the extraction procedure, low-density organic solvent together with some little aqueous phase was separated by using a disposable glass Pasteur pipette. Next, the flow of the aqueous phase was stopped by successive dipping the capillary tip of the pipette into anhydrous Na(2)SO(4). The upper organic layer was then removed simply with a microsyringe and injected into the high-performance liquid chromatography system. Experimental parameters that affect the extraction efficiency were investigated and optimized. Under optimal extraction conditions, the extraction recoveries ranged from 25 to 86%. Good linearity with coefficients with the square of correlation coefficients ranging from 0.9984 to 0.9998 was observed in the concentration range of 0.001-0.5 μg/mL. The relative standard deviations ranged from 4.1 to 9.3% (n = 5) for all compounds. The limits of detection ranged from 0.021 to 0.046 ng/mL. The method was successfully applied for the determination of parabens in tap water and fruit juice samples and good recoveries (61-108%) were achieved for spiked samples.

  15. Ca/Alq3 hybrid cathode buffer layer for the optimization of organic solar cells based on a planar heterojunction

    NASA Astrophysics Data System (ADS)

    El Jouad, Z.; Barkat, L.; Stephant, N.; Cattin, L.; Hamzaoui, N.; Khelil, A.; Ghamnia, M.; Addou, M.; Morsli, M.; Béchu, S.; Cabanetos, C.; Richard-Plouet, M.; Blanchard, P.; Bernède, J. C.

    2016-11-01

    Use of efficient anode cathode buffer layer (CBL) is crucial to improve the efficiency of organic photovoltaic cells. Here we show that using a double CBL, Ca/Alq3, allows improving significantly cell performances. The insertion of Ca layer facilitates electron harvesting and blocks hole collection, leading to improved charge selectivity and reduced leakage current, whereas Alq3 blocks excitons. After optimisation of this Ca/Alq3 CBL using CuPc as electron donor, it is shown that it is also efficient when SubPc is substituted to CuPc in the cells. In that case we show that the morphology of the SubPc layer, and therefore the efficiency of the cells, strongly depends on the deposition rate of the SubPc film. It is necessary to deposit slowly (0.02 nm/s) the SubPc films because at higher deposition rate (0.06 nm/s) the films are porous, which induces leakage currents and deterioration of the cell performances. The SubPc layers whose formations are kinetically driven at low deposition rates are more uniform, whereas those deposited faster exhibit high densities of pinholes.

  16. UV-ozone-treated ultra-thin NaF film as anode buffer layer on organic light emitting devices.

    PubMed

    Chen, Yu-Cheng; Kao, Po-Ching; Chu, Sheng-Yuan

    2010-06-21

    An ultra-thin NaF film was thermally deposited between ITO and NPB as the buffer layer and then treated with the ultraviolet (UV) ozone, in the fabrication of organic light emitting diodes (ITO/NaF/NPB/Alq(3)/LiF/Al) to study its effect on hole-injection properties. The treatment drastically transforms the role of NaF film from hole-blocking to hole-injecting. This transformation is elucidated using hole-only devices, energy band measurement, surface energy, surface polarity, and X-ray photoelectron spectra. With the optimal thickness (3 nm) of the UV-ozone-treated NaF layer, the device performance is significantly improved, with a turn-on voltage, maximum luminance, and maximum current efficiency of 2.5 V, 15700 cd/m(2), and 4.9 cd/A, respectively. Results show that NaF film is not only a hole-blocking layer, but also a promising hole-injecting layer after UV-ozone treatment.

  17. UV-ozone-treated ultra-thin NaF film as anode buffer layer on organic light emitting devices.

    PubMed

    Chen, Yu-Cheng; Kao, Po-Ching; Chu, Sheng-Yuan

    2010-06-21

    An ultra-thin NaF film was thermally deposited between ITO and NPB as the buffer layer and then treated with the ultraviolet (UV) ozone, in the fabrication of organic light emitting diodes (ITO/NaF/NPB/Alq(3)/LiF/Al) to study its effect on hole-injection properties. The treatment drastically transforms the role of NaF film from hole-blocking to hole-injecting. This transformation is elucidated using hole-only devices, energy band measurement, surface energy, surface polarity, and X-ray photoelectron spectra. With the optimal thickness (3 nm) of the UV-ozone-treated NaF layer, the device performance is significantly improved, with a turn-on voltage, maximum luminance, and maximum current efficiency of 2.5 V, 15700 cd/m(2), and 4.9 cd/A, respectively. Results show that NaF film is not only a hole-blocking layer, but also a promising hole-injecting layer after UV-ozone treatment. PMID:20588585

  18. Schiff base ligands and their transition metal complexes in the mixtures of ionic liquid + organic solvent: a thermodynamic study.

    PubMed

    Shekaari, Hemayat; Kazempour, Amir; Khoshalhan, Maryam

    2015-01-21

    Schiff bases and their metal complexes in the mixtures of ionic liquid (IL) + organic solvent have shown great potential in attractive oxidation catalytic processes. The efficiency of such a process is strongly dependent on the various molecular interactions occurring between components. Thermodynamic properties of these systems can provide valuable information about structural interactions. Therefore, in this work, the interactions of the IL 1-hexyl-3-methylimidazolium chloride ([HMIm]Cl) with Schiff bases in organic solvents were studied through the measurements of density, viscosity, and electrical conductivity. The effect of solvent on the interactions was examined by the solutions of IL + BPIC Schiff base + solvent (C2H6O-C3H8O-C4H10O). Moreover, the influence of Schiff base ligand and Schiff base complex structures was probed by the solutions of IL + DMA + ligand (salcn/salpr/salen) and IL + DMA + complex (VO(3-OMe-salen)/VO(salophen)/VO(salen)), respectively. Using the experimental data, some important thermodynamic properties, such as standard partial molar volume (V(0)(φ,IL)), experimental slope (Sv), viscosity B-coefficient, solvation number (B/V(0)(φ,IL) and limiting molar conductivity (Λ0) were calculated and discussed in terms of solute-solvent (IL-DMF/alcohol) and solute-cosolute (IL-Schiff base) interactions.

  19. 40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  20. 40 CFR 63.5753 - How do I calculate the combined organic HAP content of aluminum wipedown solvents and aluminum...

    Code of Federal Regulations, 2010 CFR

    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...

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

    EPA Science Inventory

    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...

  2. Effect of temperature on competitive adsorption of the solute and the organic solvent in reversed-phase liquid chromatography.

    PubMed

    Poplewska, Izabela; Piatkowski, Wojciech; Antos, Dorota

    2006-01-27

    In analysis of the temperature effect on chromatographic separations the influence of the adsorption of organic solvent on the retention properties of solute is generally not taken into account. In fact, adsorption behavior of solutes is strongly affected by competitive adsorption of organic solvents, which is temperature dependent. In this work changes of adsorption equilibrium of an organic solvent as well as a solute with temperature have been analyzed. Data of the excess adsorption of methanol from aqueous solutions on octadecyl-bonded silica have been acquired at different temperature. Experiments have been performed over a relatively narrow temperature range corresponding to typical chromatographic conditions, i.e., 10-50 degrees C. The competitive adsorption equilibria of model solutes (i.e., two homologous compounds: cyclopentanone and cyclohexanone) have been measured at different temperature and composition of the mobile phase. Temperature alterations to the retention properties were found to result from combined effects of changes in adsorption behavior of the organic solvent and of the solute. The influence of temperature on the separation selectivity has been considered.

  3. Highly efficient synthesis of endomorphin-2 under thermodynamic control catalyzed by organic solvent stable proteases with in situ product removal.

    PubMed

    Xu, Jiaxing; Sun, Honglin; He, Xuejun; Bai, Zhongzhong; He, Bingfang

    2013-02-01

    An efficient enzymatic synthesis of endomorphin-2 (EM-2) was achieved using organic solvent stable proteases in nonaqeous media, based on thermodynamic control and an in situ product removal methodology. The high stability of biocatalysts in organic solvents enabled the aleatoric modulation of the nonaqueous reaction media to shift thermodynamic equilibrium toward synthesis. Peptide Boc-Phe-Phe-NH2 was synthesized with a high yield of 96% by the solvent stable protease WQ9-2 in monophase medium with an economical molar ratio of the substrate of 1:1. The tetrapeptide Boc-Tyr-Pro-Phe-Phe-NH2 was synthesized with a yield of 88% by another organic solvent tolerant protease PT121 from Boc-Tyr-Pro-OH and Phe-Phe-NH2 in an organic-aqueous biphasic system. The reaction-separation coupling in both enzymatic processes provides "driving forces" for the synthetic reactions and gives a high yield and high productivity without purification of the intermediate, thereby making the synthesis more amenable to scale-up.

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

    NASA Astrophysics Data System (ADS)

    Sliz, Rafal; Suzuki, Yuji; Nathan, Arokia; Myllyla, Risto; Jabbour, Ghassan

    2012-09-01

    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 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.

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

    PubMed Central

    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 experiment employs heterocyclic substrates, which are important pharmaceutical building blocks. Thus, this laboratory procedure exposes students to a variety of contemporary topics in organic chemistry, including transition metal-catalyzed cross-couplings, green chemistry, and the importance of heterocycles in drug discovery, none of which are well represented in typical undergraduate organic chemistry curricula. The experimental protocol uses commercially available reagents and is useful in both organic and inorganic instructional laboratories. PMID:25774064

  6. Simultaneous recovery and purification of rice protein and phosphorus compounds from full-fat and defatted rice bran with organic solvent-free process.

    PubMed

    Watanabe, Masanori; Maeda, Isamu; Koyama, Masahiro; Nakamura, Kozo; Sasano, Kazuo

    2015-02-01

    We studied a process that enables simultaneous recovery of protein and phosphorus compounds from rice bran. Phosphorus substances in full-fat and defatted rice bran such as phytic acid and inorganic ions were solubilized under acidic conditions in the first step. After that, inorganic and/or organic phosphate salts were recovered in insoluble form under weak alkaline conditions. Furthermore, protein fractions obtained after phosphorus compounds had been removed were solubilized under alkaline conditions. After solubilization, protein fractions with high content were recovered by isoelectric precipitation (IP) followed by electrolyzed water treatment (EWT). The highest protein content (52.3 w/w%) was attained when machine defatted rice bran was treated through the process. Energy-dispersive X-ray spectroscopy (EDX) and inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses demonstrated efficient desalting from the protein fractions by EWT and higher phosphorus contents (15.1-16.4 w/w% P) in the phosphorus fractions compared with commercial phosphate rock. In addition, no heavy metal ions in either protein or phosphorus fractions were detected. These results suggest that the newly developed process is suitable for practical recovery of highly concentrated protein and phosphorus compounds from rice bran without enzymes or chemicals such as organic solvents, buffering agents, and surfactants. PMID:25174654

  7. Retention of ionisable compounds on high-performance liquid chromatography XIX. pH variation in mobile phases containing formic acid, piperazine and tris as buffering systems and methanol as organic modifier.

    PubMed

    Subirats, Xavier; Bosch, Elisabeth; Rosés, Martí

    2009-07-10

    In previous works a model to estimate the pH of methanol-aqueous buffer mobile phases from the aqueous pH and concentration of the buffer and the fraction of organic modifier was developed. This model was successfully applied and validated for buffers prepared from ammonia, acetic, phosphoric and citric acids. In the present communication this model has been extended to formic acid, piperazine and tris(hydroxymethyl)aminomethane buffers. Prior to the modelling work, the pK(a) values of the studied buffers at several methanol-water compositions were determined.

  8. [Effects of snow cover on water soluble and organic solvent soluble components during foliar litter decomposition in an alpine forest].

    PubMed

    Xu, Li-Ya; Yang, Wan-Qin; Li, Han; Ni, Xiang-Yin; He, Jie; Wu, Fu-Zhong

    2014-11-01

    Seasonal snow cover may change the characteristics of freezing, leaching and freeze-thaw cycles in the scenario of climate change, and then play important roles in the dynamics of water soluble and organic solvent soluble components during foliar litter decomposition in the alpine forest. Therefore, a field litterbag experiment was conducted in an alpine forest in western Sichuan, China. The foliar litterbags of typical tree species (birch, cypress, larch and fir) and shrub species (willow and azalea) were placed on the forest floor under different snow cover thickness (deep snow, medium snow, thin snow and no snow). The litterbags were sampled at snow formation stage, snow cover stage and snow melting stage in winter. The results showed that the content of water soluble components from six foliar litters decreased at snow formation stage and snow melting stage, but increased at snow cover stage as litter decomposition proceeded in the winter. Besides the content of organic solvent soluble components from azalea foliar litter increased at snow cover stage, the content of organic solvent soluble components from the other five foliar litters kept a continue decreasing tendency in the winter. Compared with the content of organic solvent soluble components, the content of water soluble components was affected more strongly by snow cover thickness, especially at snow formation stage and snow cover stage. Compared with the thicker snow covers, the thin snow cover promoted the decrease of water soluble component contents from willow and azalea foliar litter and restrain the decrease of water soluble component content from cypress foliar litter. Few changes in the content of water soluble components from birch, fir and larch foliar litter were observed under the different thicknesses of snow cover. The results suggested that the effects of snow cover on the contents of water soluble and organic solvent soluble components during litter decomposition would be controlled by

  9. [Effects of snow cover on water soluble and organic solvent soluble components during foliar litter decomposition in an alpine forest].

    PubMed

    Xu, Li-Ya; Yang, Wan-Qin; Li, Han; Ni, Xiang-Yin; He, Jie; Wu, Fu-Zhong

    2014-11-01

    Seasonal snow cover may change the characteristics of freezing, leaching and freeze-thaw cycles in the scenario of climate change, and then play important roles in the dynamics of water soluble and organic solvent soluble components during foliar litter decomposition in the alpine forest. Therefore, a field litterbag experiment was conducted in an alpine forest in western Sichuan, China. The foliar litterbags of typical tree species (birch, cypress, larch and fir) and shrub species (willow and azalea) were placed on the forest floor under different snow cover thickness (deep snow, medium snow, thin snow and no snow). The litterbags were sampled at snow formation stage, snow cover stage and snow melting stage in winter. The results showed that the content of water soluble components from six foliar litters decreased at snow formation stage and snow melting stage, but increased at snow cover stage as litter decomposition proceeded in the winter. Besides the content of organic solvent soluble components from azalea foliar litter increased at snow cover stage, the content of organic solvent soluble components from the other five foliar litters kept a continue decreasing tendency in the winter. Compared with the content of organic solvent soluble components, the content of water soluble components was affected more strongly by snow cover thickness, especially at snow formation stage and snow cover stage. Compared with the thicker snow covers, the thin snow cover promoted the decrease of water soluble component contents from willow and azalea foliar litter and restrain the decrease of water soluble component content from cypress foliar litter. Few changes in the content of water soluble components from birch, fir and larch foliar litter were observed under the different thicknesses of snow cover. The results suggested that the effects of snow cover on the contents of water soluble and organic solvent soluble components during litter decomposition would be controlled by

  10. Solvent-free synthesis of new inorganic-organic hybrid solids with finely tuned manganese oxalate structures.

    PubMed

    Luan, Lindong; Li, Jing; Yin, Changzhen; Lin, Zhien; Huang, Hui

    2015-04-01

    Three manganese phosphate-oxalates have been synthesized under solvent-free conditions. These inorganic-organic hybrid solids are based on a pcu-type topology with nanobelt-like, sql-, and cds-type manganese oxalate skeletons, respectively. The amine molecules play a novel structure-directing role for the formation of different metal-organic skeletons within a specific framework topology. PMID:25742937

  11. Solvent vapour mediated spontaneous healing of self-organized defects of liquid crystal films.

    PubMed

    Ravi, Bolleddu; Mukherjee, Rabibrata; Bandyopadhyay, Dipankar

    2015-01-01

    Ultrathin liquid crystal films showed a nematic to isotropic transition when exposed to solvent vapour for a short duration while a reverse isotropic to nematic transition was observed when the film was isolated from the solvent exposure. The phase transitions were associated with the appearance and fading of surface patterns as the solvent molecules diffused into and out of the film matrix, resulting in the destruction or restoration of the orientational order. A long-time solvent vapour exposure caused the dewetting of the film on the surface, which was demonstrated by the formation of holes and their growth in size with the progress of time. Even at this stage, withdrawal of the solvent exposure produced an array of nematic fingers, which nearly self-healed the dewetted holes. The change in contact angle due to the phase transition coupled with the imbalance of osmotic pressure across the contact line due to the differential rate of solvent evaporation from the film and the hole helped the fingers to grow towards the centre of the hole. The appearance of the fingers upon withdrawal of the solvent exposure and their disappearance upon exposure to solvent were also found to be a nearly reversible process. These findings could significantly contribute to the development of vapour sensors and self-healing surfaces using liquid crystal thin films. PMID:25372336

  12. Solvent vapour mediated spontaneous healing of self-organized defects of liquid crystal films.

    PubMed

    Ravi, Bolleddu; Mukherjee, Rabibrata; Bandyopadhyay, Dipankar

    2015-01-01

    Ultrathin liquid crystal films showed a nematic to isotropic transition when exposed to solvent vapour for a short duration while a reverse isotropic to nematic transition was observed when the film was isolated from the solvent exposure. The phase transitions were associated with the appearance and fading of surface patterns as the solvent molecules diffused into and out of the film matrix, resulting in the destruction or restoration of the orientational order. A long-time solvent vapour exposure caused the dewetting of the film on the surface, which was demonstrated by the formation of holes and their growth in size with the progress of time. Even at this stage, withdrawal of the solvent exposure produced an array of nematic fingers, which nearly self-healed the dewetted holes. The change in contact angle due to the phase transition coupled with the imbalance of osmotic pressure across the contact line due to the differential rate of solvent evaporation from the film and the hole helped the fingers to grow towards the centre of the hole. The appearance of the fingers upon withdrawal of the solvent exposure and their disappearance upon exposure to solvent were also found to be a nearly reversible process. These findings could significantly contribute to the development of vapour sensors and self-healing surfaces using liquid crystal thin films.

  13. Distribution coefficients of vitamin B2 in hydrophilic organic solvent-aqueous salt solution systems

    NASA Astrophysics Data System (ADS)

    Korenman, Ya. I.; Mokshina, N. Ya.; Zykov, A. V.

    2010-03-01

    Distribution coefficients of vitamin B2 in hydrophilic solvent ( n-butanol, isopropanol, acetone, ethyl acetate, and their mixtures)-aqueous salt (potassium chloride, sodium fluoride, and ammonium sulfate salting-out agents) solution systems were calculated. The synergic effect and optimum proportions of components in the solvent mixture for efficient extraction of vitamin B2 from aqueous solutions were established.

  14. Use of volatile organic solvents in headspace liquid-phase microextraction by direct cooling of the organic drop using a simple cooling capsule.

    PubMed

    Ghiasvand, Ali Reza; Yazdankhah, Fatemeh; Hajipour, Somayeh

    2016-08-01

    A low-cost and simple cooling-assisted headspace liquid-phase microextraction device for the extraction and determination of 2,6,6-trimethyl-1,3 cyclohexadiene-1-carboxaldehyde (safranal) in Saffron samples, using volatile organic solvents, was fabricated and evaluated. The main part of the cooling-assisted headspace liquid-phase microextraction system was a cooling capsule, with a Teflon microcup to hold the extracting organic solvent, which is able to directly cool down the extraction phase while the sample matrix is simultaneously heated. Different experimental factors such as type of organic extraction solvent, sample temperature, extraction solvent temperature, and extraction time were optimized. The optimal conditions were obtained as: extraction solvent, methanol (10 μL); extraction temperature, 60°C; extraction solvent temperature, 0°C; and extraction time, 20 min. Good linearity of the calibration curve (R(2) = 0.995) was obtained in the concentration range of 0.01-50.0 μg/mL. The limit of detection was 0.001 μg/mL. The relative standard deviation for 1.0 μg/mL of safranal was 10.7% (n = 6). The proposed cooling-assisted headspace liquid-phase microextraction device was coupled (off-line) to high-performance liquid chromatography and used for the determination of safranal in Saffron samples. Reasonable agreement was observed between the results of the cooling-assisted headspace liquid-phase microextraction high-performance liquid chromatography method and those obtained by a validated ultrasound-assisted solvent extraction procedure. PMID:27311349

  15. Use of volatile organic solvents in headspace liquid-phase microextraction by direct cooling of the organic drop using a simple cooling capsule.

    PubMed

    Ghiasvand, Ali Reza; Yazdankhah, Fatemeh; Hajipour, Somayeh

    2016-08-01

    A low-cost and simple cooling-assisted headspace liquid-phase microextraction device for the extraction and determination of 2,6,6-trimethyl-1,3 cyclohexadiene-1-carboxaldehyde (safranal) in Saffron samples, using volatile organic solvents, was fabricated and evaluated. The main part of the cooling-assisted headspace liquid-phase microextraction system was a cooling capsule, with a Teflon microcup to hold the extracting organic solvent, which is able to directly cool down the extraction phase while the sample matrix is simultaneously heated. Different experimental factors such as type of organic extraction solvent, sample temperature, extraction solvent temperature, and extraction time were optimized. The optimal conditions were obtained as: extraction solvent, methanol (10 μL); extraction temperature, 60°C; extraction solvent temperature, 0°C; and extraction time, 20 min. Good linearity of the calibration curve (R(2) = 0.995) was obtained in the concentration range of 0.01-50.0 μg/mL. The limit of detection was 0.001 μg/mL. The relative standard deviation for 1.0 μg/mL of safranal was 10.7% (n = 6). The proposed cooling-assisted headspace liquid-phase microextraction device was coupled (off-line) to high-performance liquid chromatography and used for the determination of safranal in Saffron samples. Reasonable agreement was observed between the results of the cooling-assisted headspace liquid-phase microextraction high-performance liquid chromatography method and those obtained by a validated ultrasound-assisted solvent extraction procedure.

  16. Economic and environmental benefits of product substitution for organic solvents. Final report

    SciTech Connect

    O'Connor, S.C.

    1991-05-01

    U.S. Army installations require solvents for effective maintenance and equipment refurbishing operations. Spent solvent generation has become a significant environmental and economic concern. Of increasing concern are toxic air emissions, threshold limit values, and increasing restriction on land disposal. Coupled with these environmental issues is the rising cost of both waste disposal and new solvent purchase. This manuscript evaluates the environmental protection and economic benefits of substituting aqueous terpene-based cleaners for petroleum-based Stoddard solvent, currently used in parts cleaning. With characteristics such as low volatility, biodegradability, and reduction of land disposal, terpene cleaners have become the favored substitution alternative. This research showed that implementing terpene cleaner substitution for Stoddard solvent requires a site-specific study of each installation which will include waste recycling, disposal of sludge and rinse water, landfills, contamination of soils and economic analysis.

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

    PubMed Central

    Cao, Yue; Shi, Li-Li; Cao, Qing-Ri; Yang, Mingshi; Cui, Jing-Hao

    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) and polyethylene glycol 6000 (PEG 6000) as hydrophilic polymers, sodium hydroxide (NaOH) as an alkalizer, and poloxamer 188 as a surfactant by a lyophilization method. In-vitro dissolution rate and physicochemical properties of the OSF-SDs were characterized using the USP I basket method, differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and fourier transform-infrared (FT-IR) spectroscopy. In addition, the oral bioavailability of OSF-SDs in rats was evaluated by using TEL bulk powder as a reference. The dissolution rates of the OSF-SDs were significantly enhanced as compared to TEL bulk powder. 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 to the reference. This study demonstrated that OSF-SDs can be a promising method to enhance the dissolution rate and oral bioavailability of TEL. PMID:27642309

  18. Effects of industrial effluents, heavy metals, and organic solvents on mallard embryo development

    USGS Publications Warehouse

    Hoffman, D.J.; Eastin, W.C.

    1981-01-01

    Mallard eggs were externally exposed at 3 and 8 days of incubation to 7 different industrial effluents and to 7 different heavy metal, organic solvent, and petroleum solutions to screen for potential embryo-toxic effects. This route of exposure was chosen in order to simulate the transfer of pollutant from the plumage of aquatic birds to their eggs. Five of the effluents including mineral pigment, scouring effluent, sludge, and tannery effluent resulted in small but significant reductions in embryonic growth. Treatment with methyl mercury chloride solution of 50 ppm (Hg) impaired embryonic growth but much higher concentrations were required to affect survival and cause teratogenic effects. Oil used to suppress road dust was the most toxic of the pollutants tested and only 0.5 microliter/egg caused 60% mortality by 18 days of development. These findings, in combination with other studies suggest that petroleum pollutants, or effluents in combination with petroleum, may pose a hazard to birds' eggs when exposure is by this route.

  19. Seasonal variation of solvent extractable organic compounds in the aerosols in Qingdao, China

    NASA Astrophysics Data System (ADS)

    Guo, Z. G.; Sheng, L. F.; Feng, J. L.; Fang, Ming

    The solvent extractable organic compounds in 22 seasonal total suspended particulate samples collected in Qingdao, China during June 2001-May 2002 were analyzed using gas chromatograph/mass-selective detector. Included in these samples were three from Asian dust episodes. The characteristics and abundance of the n-alkanes, polycyclic aromatic hydrocarbons and fatty acids were determined. Distinct seasonal variations were detected in the Qingdao samples. The n-alkanes were found to contain substantial amounts of petroleum residues (56.0% in summer, 64.4% in fall, 77.6% in spring and 81.5% in winter). The winter polycyclic aromatic hydrocarbons (PAHs) were from combustion sources including coal burning for space-heating and the average PAH yield was 14.4 times higher than that in summer. The

  20. Microwave activation of electrochemical processes: enhanced electrodehalogenation in organic solvent media.

    PubMed

    Tsai, Yu-Chen; Coles, Barry A; Compton, Richard G; Marken, Frank

    2002-08-21

    The effect of high-intensity microwave radiation focused into a "hot spot" region in the vicinity of an electrode on electrochemical processes with and without coupled chemical reaction steps has been investigated in organic solvent media. First, the electrochemically reversible oxidation of ferrocene in acetonitrile and DMF is shown to be affected by microwave-induced thermal activation, resulting in increased currents and voltammetric wave shape effects. A FIDAP simulation investigation allows quantitative insight into the temperature distribution and concentration gradients at the electrode / solution interface. Next, the effect of intense microwave radiation on electroorganic reactions is considered for the case of ECE processes. Experimental data for the reduction of p-bromonitrobenzene, o-bromonitrobenzene, and m-iodonitrobenzene in DMF and acetonitrile are analyzed in terms of an electron transfer (E), followed by a chemical dehalogenation step (C), and finally followed by another electron-transfer step (E). The presence of the "hot spot" in the solution phase favors processes with high activation barriers.

  1. Bacterial assisted degradation of chlorpyrifos: The key role of environmental conditions, trace metals and organic solvents.

    PubMed

    Khalid, Saira; Hashmi, Imran; Khan, Sher Jamal

    2016-03-01

    Wastewater from pesticide industries, agricultural or surface runoff containing pesticides and their residues has adverse environmental impacts. Present study demonstrates effect of petrochemicals and trace metals on chlorpyrifos (CP) biotransformation often released in wastewater of agrochemical industry. Biodegradation was investigated using bacterial strain Pseudomonas kilonensis SRK1 isolated from wastewater spiked with CP. Optimal environmental conditions for CP removal were CFU (306 × 10(6)), pH (8); initial CP concentration (150 mg/L) and glucose as additional carbon source. Among various organic solvents (petrochemicals) used in this study toluene has stimulatory effect on CP degradation process using SRK1, contrary to this benzene and phenol negatively inhibited degradation process. Application of metal ions (Cu (II), Fe (II) Zn (II) at low concentration (1 mg/L) took part in biochemical reaction and positively stimulated CP degradation process. Metal ions at high concentrations have inhibitory effect on degradation process. A first order growth model was shown to fit the data. It could be concluded that both type and concentration of metal ions and petrochemicals can affect CP degradation process.

  2. Monitoring of the aerobe biodegradation of chlorinated organic solvents by stable isotope analysis

    NASA Astrophysics Data System (ADS)

    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. Source profiles of volatile organic compounds associated with solvent use in Beijing, China

    NASA Astrophysics Data System (ADS)

    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.

  4. Contrasting voltammetric behavior of different forms of vitamin A in aprotic organic solvents.

    PubMed

    Tan, Ying Shan; Urbančok, Dejan; Webster, Richard D

    2014-07-24

    Six of the major vitamers and provitamins comprising vitamin A (β-carotene, retinoic acid, retinol, retinyl palmitate, retinyl acetate, and retinal) were examined using voltammetric and controlled potential electrolysis techniques in the aprotic organic solvents acetonitrile and dichloromethane at glassy carbon and platinum electrodes. All of the compounds underwent oxidation and reduction processes and displayed a number of similarities and differences in terms of the number of redox processes and chemical reversibility of the voltammetric responses. The electrochemical properties of the compounds were strongly influenced by the functional groups on the unsaturated phytyl chains (carboxylic acid, alcohol, ester, or aldehyde groups), and not only on the fully conjugated hydrocarbon unit which is common to all forms of vitamin A. The compounds were reduced at potentials between approximately -1.7 and -2.6 vs (Fc/Fc(+))/V (Fc = ferrocene) and oxidized at potentials between approximately +0.2 and +0.7 vs (Fc/Fc(+))/V. The average number of electrons transferred per molecule under long time scale electrolysis experiments were found to vary between 0.4 and 4 electrons depending on the exact molecular structure and experimental conditions. PMID:24984099

  5. Electrochemistry of Simple Organometallic Models of Iron-Iron Hydrogenases in Organic Solvent and Water.

    PubMed

    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.

  6. Extracellular vesicles are rapidly purified from human plasma by PRotein Organic Solvent PRecipitation (PROSPR)

    PubMed Central

    Gallart-Palau, Xavier; Serra, Aida; Wong, Andrew See Weng; Sandin, Sara; Lai, Mitchell K. P.; Chen, Christopher P.; Kon, Oi Lian; Sze, Siu Kwan

    2015-01-01

    Extracellular vesicles (EVs) such as exosomes and microvesicles mediate intercellular communication and regulate a diverse range of crucial biological processes. Host cells that are damaged, infected or transformed release biomarker-containing EVs into the peripheral circulation, where they can be readily accessed for use in diagnostic or prognostic testing. However, current methods of EV isolation from blood plasma are complex and often require relatively large sample volumes, hence are inefficient for widespread use in clinical settings. Here, we report a novel and inexpensive method of rapidly isolating EVs from small volumes of human blood plasma by PRotein Organic Solvent PRecipitation (PROSPR). PROSPR encompasses a rapid three-step protocol to remove soluble proteins from plasma via precipitation in cold acetone, leaving the lipid-encapsulated EVs behind in suspension. This generates higher purity EVs that can then be obtained from filtration or classical ultracentrifugation methods. We foresee that PROSPR-based purification of EVs will significantly accelerate the discovery of new disease biomarkers and the characterization of EVs with potential for clinical applications. PMID:26419333

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

    PubMed

    Cao, Yue; Shi, Li-Li; Cao, Qing-Ri; Yang, Mingshi; Cui, Jing-Hao

    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) and polyethylene glycol 6000 (PEG 6000) as hydrophilic polymers, sodium hydroxide (NaOH) as an alkalizer, and poloxamer 188 as a surfactant by a lyophilization method. In-vitro dissolution rate and physicochemical properties of the OSF-SDs were characterized using the USP I basket method, differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and fourier transform-infrared (FT-IR) spectroscopy. In addition, the oral bioavailability of OSF-SDs in rats was evaluated by using TEL bulk powder as a reference. The dissolution rates of the OSF-SDs were significantly enhanced as compared to TEL bulk powder. 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 to the reference. This study demonstrated that OSF-SDs can be a promising method to enhance the dissolution rate and oral bioavailability of TEL. PMID:27642309

  8. Time-course data analysis of gene expression profiles reveals purR regulon concerns in organic solvent tolerance in Escherichia coli.

    PubMed

    Shimizu, Kazunori; Hayashi, Shuhei; Doukyu, Noriyuki; Kobayashi, Takeshi; Honda, Hiroyuki

    2005-01-01

    A time-course gene-expression profile was generated for Escherichia coli TK31 when it was exposed to an organic solvent mixture, and classified by fuzzy adaptive resonance theory (Fuzzy ART). It was found that the purR regulon plays an important role in the organic solvent tolerance (OST) of E. coli.

  9. Long-Term Occupational Exposure to Organic Solvents Affects Color Vision, Contrast Sensitivity and Visual Fields

    PubMed Central

    Costa, Thiago Leiros; Barboni, Mirella Telles Salgueiro; Moura, Ana Laura de Araújo; Bonci, Daniela Maria Oliveira; Gualtieri, Mirella; de Lima Silveira, Luiz Carlos; Ventura, Dora Fix

    2012-01-01

    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. PMID:22916187

  10. Tuning the interfacial hole injection barrier between p-type organic materials and Co using a MoO{sub 3} buffer layer

    SciTech Connect

    Wang Yuzhan; Wee, Andrew T. S.; Cao Liang; Qi Dongchen; Chen Wei; Gao Xingyu

    2012-08-01

    We demonstrate that the interfacial hole injection barrier {Delta}{sub h} between p-type organic materials (i.e., CuPc and pentacene) and Co substrate can be tuned by the insertion of a MoO{sub 3} buffer layer. Using ultraviolet photoemission spectroscopy, it was found that the introduction of MoO{sub 3} buffer layer effectively reduces the hole injection barrier from 0.8 eV to 0.4 eV for the CuPc/Co interface, and from 1.0 eV to 0.4 eV for the pentacene/Co interface, respectively. In addition, by varying the thickness of the buffer, the tuning effect of {Delta}{sub h} is shown to be independent of the thickness of MoO{sub 3} interlayer at both CuPc/Co and pentacene/Co interfaces. This Fermi level pinning effect can be explained by the integer charge-transfer model. Therefore, the MoO{sub 3} buffer layer has the potential to be applied in p-type organic spin valve devices to improve the device performance via reducing the interfacial hole injection barrier.

  11. On the effect of ion pairing of Keggin type polyanions with quaternary ammonium cations on redox potentials in organic solvents.

    PubMed

    Chen, Bo; Neumann, Ronny

    2016-08-10

    The electrochemical properties of Keggin type polyoxometalates Qn[XW12O40] (X = P, Si, B; Q = n-tetraoctylammonium and n-trioctylmethylammonium) in organic solvents were investigated in order to understand the interrelation between the redox potentials, solvents and ion pairing. A logarithmic correlation between the dielectric constant of the solvent (ε ranged from 4.8 to 46.6) and the reduction potential of the [PW12O4](3-)/[PW12O4](4-) couple was found. This reduction potential increased significantly when the surface charge of the polyoxometalate went from 3- to 5-. The investigation of the ion pairing properties by diffusion NMR revealed the presence of intimate ion pairs in less polar solvents (e.g. dichloromethane) and less compact ion pairs in more polar solvents (e.g. DMSO). Using a V atom within the polyoxometalate an NMR experiment showed that a n-trioctylmethyl ammonium cation bonded to the polyoxometalate anion more intimately than a n-tetraoctyl ammonium cation. PMID:27465599

  12. Solvent-modified ultrafast decay dynamics in conjugated polymer/dye labeled single stranded DNA

    NASA Astrophysics Data System (ADS)

    Kim, Inhong; Kang, Mijeong; Woo, Han Young; Oh, Jin-Woo; Kyhm, Kwangseuk

    2015-07-01

    We have investigated that organic solvent (DMSO, dimethyl sulfoxide) modifies energy transfer efficiency between conjugated polymers (donors) and fluorescein-labeled single stranded DNAs (acceptors). In a mixture of buffer and organic solvent, fluorescence of the acceptors is significantly enhanced compared to that of pure water solution. This result can be attributed to change of the donor-acceptor environment such as decreased hydrophobicity of polymers, screening effect of organic solvent molecules, resulting in an enhanced energy transfer efficiency. Time-resolved fluorescence decay of the donors and the acceptors was modelled by considering the competition between the energy harvesting Foerster resonance energy transfer and the energy-wasting quenching. This enables to quantity that the Foerster distance (R0 = 43.3 Å) and resonance energy transfer efficiency (EFRET = 58.7 %) of pure buffer solution become R0 = 38.6 Å and EFRET = 48.0 % when 80% DMSO/buffer mixture is added.

  13. NMR Chemical Shift Ranges of Urine Metabolites in Various Organic Solvents.

    PubMed

    Görling, Benjamin; Bräse, Stefan; Luy, Burkhard

    2016-01-01

    Signal stability is essential for reliable multivariate data analysis. Urine samples show strong variance in signal positions due to inter patient differences. Here we study the exchange of the solvent of a defined urine matrix and how it affects signal and integral stability of the urinary metabolites by NMR spectroscopy. The exchange solvents were methanol, acetonitrile, dimethyl sulfoxide, chloroform, acetone, dichloromethane, and dimethyl formamide. Some of these solvents showed promising results with a single batch of urine. To evaluate further differences between urine samples, various acid, base, and salt solutions were added in a defined way mimicking to some extent inter human differences. Corresponding chemical shift changes were monitored. PMID:27598217

  14. NMR Chemical Shift Ranges of Urine Metabolites in Various Organic Solvents.

    PubMed

    Görling, Benjamin; Bräse, Stefan; Luy, Burkhard

    2016-09-02

    Signal stability is essential for reliable multivariate data analysis. Urine samples show strong variance in signal positions due to inter patient differences. Here we study the exchange of the solvent of a defined urine matrix and how it affects signal and integral stability of the urinary metabolites by NMR spectroscopy. The exchange solvents were methanol, acetonitrile, dimethyl sulfoxide, chloroform, acetone, dichloromethane, and dimethyl formamide. Some of these solvents showed promising results with a single batch of urine. To evaluate further differences between urine samples, various acid, base, and salt solutions were added in a defined way mimicking to some extent inter human differences. Corresponding chemical shift changes were monitored.

  15. NMR Chemical Shift Ranges of Urine Metabolites in Various Organic Solvents

    PubMed Central

    Görling, Benjamin; Bräse, Stefan; Luy, Burkhard

    2016-01-01

    Signal stability is essential for reliable multivariate data analysis. Urine samples show strong variance in signal positions due to inter patient differences. Here we study the exchange of the solvent of a defined urine matrix and how it affects signal and integral stability of the urinary metabolites by NMR spectroscopy. The exchange solvents were methanol, acetonitrile, dimethyl sulfoxide, chloroform, acetone, dichloromethane, and dimethyl formamide. Some of these solvents showed promising results with a single batch of urine. To evaluate further differences between urine samples, various acid, base, and salt solutions were added in a defined way mimicking to some extent inter human differences. Corresponding chemical shift changes were monitored. PMID:27598217

  16. A case study on co-exposure to a mixture of organic solvents in a Tunisian adhesive-producing company

    PubMed Central

    2011-01-01

    Objectives to assess environmental and biological monitoring of exposure to organic solvents in a glue-manufacturing company in Sfax, Tunisia. Methods Exposure of volunteer workers, in the solvented glue-work-stations, in the control laboratory and in the storage rooms of the finished products, was assessed through indoor-air and urine measurements. Informed consent of the workers was obtained. Results and discussion The exposure indexes were found with high values in the solvented workshop as well as in the control laboratory and were respectively, 8.40 and 3.12. These indexes were also correlated with hexane and toluene indoor air concentrations. As to urine, the obtained results for the 2,5-hexandione and hippuric acid, metabolites of hexane and toluene, respectively, were in accord with the indoor-air measurements, with an average of 0.46 mg/l and 1240 mg/g of creatinine. Conclusion This study assessed for the first time biological exposure to organic solvents used in Tunisian adhesive industries. Although values are likely to underestimate true exposure levels, some figures exceed European and American occupational exposure guidelines. PMID:22082240

  17. The effect of organic solvent, temperature and mixing time on the production of oil from Moringa oleifera seeds

    NASA Astrophysics Data System (ADS)

    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.

  18. Interfacial Engineering Importance of Bilayered ZnO Cathode Buffer on the Photovoltaic Performance of Inverted Organic Solar Cells.

    PubMed

    Ambade, Rohan B; Ambade, Swapnil B; Mane, Rajaram S; Lee, Soo-Hyoung

    2015-04-22

    The role of cathode buffer layer (CBL) is crucial in determining the power conversion efficiency (PCE) of inverted organic solar cells (IOSCs). The hallmarks of a promising CBL include high transparency, ideal energy levels, and tendency to offer good interfacial contact with the organic bulk-heterojunction (BHJ) layers. Zinc oxide (ZnO), with its ability to form numerous morphologies in juxtaposition to its excellent electron affinity, solution processability, and good transparency is an ideal CBL material for IOSCs. Technically, when CBL is sandwiched between the BHJ active layer and the indium-tin-oxide (ITO) cathode, it performs two functions, namely, electron collection from the photoactive layer that is effectively carried out by morphologies like nanoparticles or nanoridges obtained by ZnO sol-gel (ZnO SG) method through an accumulation of individual nanoparticles and, second, transport of collected electrons toward the cathode, which is more effectively manifested by one-dimensional (1D) nanostructures like ZnO nanorods (ZnO NRs). This work presents the use of bilayered ZnO CBL in IOSCs of poly(3-hexylthiophene) (P3HT)/[6, 6]-phenyl-C60-butyric acid methyl ester (PCBM) to overcome the limitations offered by a conventionally used single layer CBL. We found that the PCE of IOSCs with an appropriate bilayer CBL comprising of ZnO NRs/ZnO SG is ∼18.21% higher than those containing ZnO SG/ZnO NRs. We believe that, in bilayer ZnO NRs/ZnO SG, ZnO SG collects electrons effectively from photoactive layer while ZnO NRs transport them further to ITO resulting significant increase in the photocurrent to achieve highest PCE of 3.70%. The enhancement in performance was obtained through improved interfacial engineering, enhanced electrical properties, and reduced surface/bulk defects in bilayer ZnO NRs/ZnO SG. This study demonstrates that the novel bilayer ZnO CBL approach of electron collection/transport would overcome crucial interfacial recombination issues and

  19. Interfacial Engineering Importance of Bilayered ZnO Cathode Buffer on the Photovoltaic Performance of Inverted Organic Solar Cells.

    PubMed

    Ambade, Rohan B; Ambade, Swapnil B; Mane, Rajaram S; Lee, Soo-Hyoung

    2015-04-22

    The role of cathode buffer layer (CBL) is crucial in determining the power conversion efficiency (PCE) of inverted organic solar cells (IOSCs). The hallmarks of a promising CBL include high transparency, ideal energy levels, and tendency to offer good interfacial contact with the organic bulk-heterojunction (BHJ) layers. Zinc oxide (ZnO), with its ability to form numerous morphologies in juxtaposition to its excellent electron affinity, solution processability, and good transparency is an ideal CBL material for IOSCs. Technically, when CBL is sandwiched between the BHJ active layer and the indium-tin-oxide (ITO) cathode, it performs two functions, namely, electron collection from the photoactive layer that is effectively carried out by morphologies like nanoparticles or nanoridges obtained by ZnO sol-gel (ZnO SG) method through an accumulation of individual nanoparticles and, second, transport of collected electrons toward the cathode, which is more effectively manifested by one-dimensional (1D) nanostructures like ZnO nanorods (ZnO NRs). This work presents the use of bilayered ZnO CBL in IOSCs of poly(3-hexylthiophene) (P3HT)/[6, 6]-phenyl-C60-butyric acid methyl ester (PCBM) to overcome the limitations offered by a conventionally used single layer CBL. We found that the PCE of IOSCs with an appropriate bilayer CBL comprising of ZnO NRs/ZnO SG is ∼18.21% higher than those containing ZnO SG/ZnO NRs. We believe that, in bilayer ZnO NRs/ZnO SG, ZnO SG collects electrons effectively from photoactive layer while ZnO NRs transport them further to ITO resulting significant increase in the photocurrent to achieve highest PCE of 3.70%. The enhancement in performance was obtained through improved interfacial engineering, enhanced electrical properties, and reduced surface/bulk defects in bilayer ZnO NRs/ZnO SG. This study demonstrates that the novel bilayer ZnO CBL approach of electron collection/transport would overcome crucial interfacial recombination issues and

  20. Comparison of neurobehavioral function in workers exposed to a mixture of organic and inorganic lead and in workers exposed to solvents.

    PubMed

    Bolla, K I; Schwartz, B S; Stewart, W; Rignani, J; Agnew, J; Ford, D P

    1995-02-01

    The neurobehavioral effects of lead (organic and inorganic) and organic solvents were compared in 386 U.S. workers (52 reference, 190 lead, and 144 solvent workers). The association between neurobehavioral test performance and duration of exposure to lead or solvents was also examined and compared. The neurobehavioral test battery consisted of examiner and computer-administered neurobehavioral tests, a test of olfactory function, and questionnaires that assessed neuropsychiatric symptoms. Adjusted mean differences on the neurobehavioral test scores were estimated by comparing the exposed group to the referent group using linear regression and adjusting for premorbid intellectual ability, age, and race. Both lead and solvents were associated with diminished neurobehavioral performance in all neurobehavioral areas tested. Specifically, while lead and solvent exposure had the same magnitude of adverse effects on tests of manual dexterity, lead exposure was associated with greater adverse effects on memory and learning tests but with less adverse effects on executive/motor tests and on a test of olfaction than solvent exposure. An elevated number of neuropsychiatric symptoms was reported by 7% of the referent group, 43% of the lead group, and 15% of the solvent group. For exposure duration of < or = 10 years, more neurobehavioral decrements were found in the solvent group relative to the lead group. However, for exposure duration of > or = 18 years, the lead group showed more decrements than the solvent group. Overall, these data suggest differences in neurobehavioral functioning between the lead (organic and inorganic) and solvent exposed workers examined in this study. PMID:7755013